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1

Effects of Ocean Acidification on Early Life Stages of Shrimp (Pandalus borealis) and Mussel (Mytilus edulis)  

Microsoft Academic Search

Ocean acidification (OA) resulting from anthropogenic emissions of carbon dioxide (CO2) has already lowered and is predicted to further lower surface ocean pH. There is a particular need to study effects of OA on organisms living in cold-water environments due to the higher solubility of CO2 at lower temperatures. Mussel larvae (Mytilus edulis) and shrimp larvae (Pandalus borealis) were kept

Renée Katrin Bechmann; Ingrid Christina Taban; Stig Westerlund; Brit Fjone Godal; Maj Arnberg; Sjur Vingen; Anna Ingvarsdottir; Thierry Baussant

2011-01-01

2

Microbial changes and growth of Listeria monocytogenes during chilled storage of brined shrimp (Pandalus borealis).  

PubMed

Thirteen storage trials and ten challenge tests were carried out to examine microbial changes, spoilage and the potential growth of Listeria monocytogenes in brined shrimp (Pandalus borealis). Shrimp in brine as well as brined and drained shrimp in modified atmosphere packaging (MAP) were produced and studied. Different recipes were used to study the effect of preserving parameters (organic acids, pH and NaCl) on growth of microorganisms and shelf life at 7-8 degrees C or 12 degrees C. Particularly, brines with different concentrations of (i) benzoic, citric and sorbic acids or (ii) acetic, citric and lactic acids were studied. Furthermore, the effect of adding diacetate to brined shrimp was evaluated. A single batch of cooked and peeled shrimp was used to study both industrially and manually processed brined shrimp with respect to the effect of process hygiene on microbial changes and the shelf life of products. Concentrations of microorganisms on newly produced brined shrimp from an industrial scale processing line were 1.0-2.3 log (CFU g(-1)) higher than comparable concentrations in manually processed samples. This resulted in a substantially shorter shelf life and a more diverse spoilage microflora of the industrially processed brined shrimp. In addition, shelf life of brined shrimp was affected by the types and concentrations of organic acids and by the storage temperature as expected. The effect of MAP was less pronounced. Eighty-two isolates from the spoilage microflora of brined shrimp were identified and they included 53 lactic acid bacteria, 6 coagulase negative Staphylococcus spp., 18 Pseudomonas fluorescens and 5 yeast isolates. After storage at 7 degrees C, P. fluorescens, Enterococcus-like isolates, E. malodoratus, Carnobacterium maltaromaticum, coagulase negative Staphylococcus spp. and Lactobacillus sakei constituted the dominating microflora of shrimp in brines that contained benzoic, citric and sorbic acids as preservatives. L. sakei dominated the spoilage microflora of brined and drained MAP shrimp, and of brined shrimp preserved using acetic, citric and lactic acids, irrespective of packaging conditions. Shrimp in brine with benzoic, citric and sorbic acids prevented growth of L. monocytogenes during more than 40 days at 7 degrees C when the preserving parameters resembled those of commercial products. However, small changes in the preserving parameters and, particularly, reduced concentrations of benzoic acid led to growth of L. monocytogenes in brined shrimp. The present study provides significant new information on microbial changes, shelf life and growth of L. monocytogenes in brined shrimp. This information can facilitate development of new and safe brined shrimp products. PMID:18456355

Mejlholm, Ole; Kjeldgaard, Jette; Modberg, Anne; Vest, Mette Bohn; Bøknaes, Niels; Koort, Joanna; Björkroth, Johanna; Dalgaard, Paw

2008-06-10

3

Egg survival, embryonic development, and larval characteristics of northern shrimp ( Pandalus borealis ) females subject to different temperature and feeding conditions  

Microsoft Academic Search

Laboratory experiments on ovigerous females of northern shrimp (Pandalus borealis) were used to assess the effects of temperature and food ration on female condition during incubation and examine how combined effects of temperature and female condition influenced egg survival, embryonic development, and larval characteristics. Ovigerous females were maintained at 2°C, 5°C, and 8°C and fed on a low (three times\\/week;

Sophie Brillon; Yvan Lambert; Julian Dodson

2005-01-01

4

Catch, survey and life-history data for shrimp ( Pandalus borealis) off Jan Mayen  

NASA Astrophysics Data System (ADS)

The Jan Mayen area has an extreme environment with low temperatures and infrequent, but abrupt temperature changes. The shrimp population here is considered to be on its edge of distribution. The life-history parameters are in the same range as in other high-latitude shrimp populations and are characterized by slow growth, large size at maturation and extended longevity. Irregular and sporadic commercial exploitation limit fishing mortality and give the population life-history parameters not previously seen in other areas. The Jan Mayen shrimp are large compared to, e.g., the Barents Sea shrimp and can reach a maximum carapace length ( Lmax) of 37 mm and an age of 10-11 years. The large size at sex transformation ( L50, >24 mm) and analyses of length-frequency distributions indicate that the shrimp may be 6-7 years of age before changing sex. The change in Lmax and L50 observed during the study period is probably caused by increased natural mortality due to sudden temperature changes or due to increased predation, rather than increased growth rates. The life-history strategy of shrimp in the Jan Mayen area can be explained by factors such as depth, temperature and population density variations caused by fluctuation in recruitment and mortality. The shrimp fisheries in the Jan Mayen area began in the late 1970s and reached an annual landing of 2000 tonnes in 1985, and since then landings have oscillated around 500 tonnes depending on a combination of factors. The survey indices of stock biomass varied between 3000 and 6600 tonnes. For most years, the highest shrimp densities are at a depth of 200-299 m, while large shrimp (and therefore also female shrimp) are dominant at depths greater than 300 m. Fish community data were studied as the composition of the demersal fish community is an integrated response to environmental conditions and as predation affects the shrimp stock. Polar cod and capelin are the most abundant fish species in the study area. A high number of blue whiting was registered in 1979, but the number declined in 1980 and 1981 as temperature decreased. During the surveys in 1994 and 1995, no blue whiting was registered. A few individuals were found again in the 1999 samples. The number of Greenland halibut has declined from the beginning of the 1980s to the 1990s.

Nilssen, Einar M.; Aschan, Michaela M.

2009-10-01

5

PHYSICAL AND CHEMICAL CHANGES OF PINK SHRIMP, PANDALUS BOREALIS, HELD IN CARBON DIOXIDE MODIFIED REFRIGERATED  

E-print Network

and in ice for 11.5 days. Chemical tests for spoilage indicated that shrimp held in carbon dioxide modified, yield, solids, carotenoids, protein, salt, and pH are given. When expressed on a constant basis (salt Service, NOAA. 73 #12;tubes in the heat exchanger were made of titanium to avoid corrosion. Carbon dioxide

6

Microbiological characteristics of Pacific shrimp (Pandalus jordani).  

PubMed Central

Microorganisms associated with Pacific shrimp (Pandalus jordani) were isolated and identified. Those on the iced raw shrimp, which yielded an average count of 1.6 x 10(6), were predominantly Moraxella, Pseudomonas, Acinetobacter, Arthrobacter, and Flavobacterium-Cytophaga spp. The blanching and peeling reduced the microbial level to 3.3 x 10(4) and also selectively eliminated Moraxella spp. The microbial flora changed after each processing sequence, and the heat sensitivity and growth characteristics of the representative microbial groups suggested that the presence of Arthrobacter and Acinetobacter spp. in peeled shrimp may indicate inadequate cleaning of raw shrimp or a shorter blanching time. The presence of Moraxella and Flavobacterium-Cytophaga spp. would indicate the degree of secondary contamination, and the presence of Pseudomonas spp. would indicate the shelf-age of the processed shrimp. PMID:869532

Lee, J S; Pfeifer, D K

1977-01-01

7

Identification and quantification of astaxanthin esters in shrimp (Pandalus borealis) and in a microalga (Haematococcus pluvialis) by liquid chromatography-mass spectrometry using negative ion atmospheric pressure chemical ionization.  

PubMed

Negative ion liquid chromatography-atmospheric pressure chemical ionization mass spectrometry [negative ion LC-(APCI)MS] was used for the identification of astaxanthin esters in extracts of commercial shrimp (Pandalus borealis) and dried microalga (Haematococcus pluvialis) samples. A cleanup step using a normal phase solid phase extraction (SPE) cartridge was applied prior to analysis. Recovery experiments with astaxanthin oleate as model compound proved the applicability of this step (98.5 +/- 7.6%; n = 4). The assignment of astaxanthin esters in negative ion LC-(APCI)MS was based on the detection of the molecular ion (M*-) and the formation of characteristic fragment ions, resulting from the loss of one or two fatty acids. Quantification of individual astaxanthin esters was performed using an astaxanthin calibration curve, which was found to be linear over the required range (1-51 micromol/L; r2 = 0.9996). Detection limits, based on the intensity of M*-, a signal-to-noise ratio of 3:1, and an injection volume of 20 microL, were estimated to be 0.05 microg/mL (free astaxanthin), 0.28 microg/mL (astaxanthin-C16:0), and 0.78 microg/mL (astaxanthin-C16:0/C16:0), respectively. This LC-(APCI)MS method allows for the first time the characterization of native astaxanthin esters in P. borealis and H. pluvialis without using time-consuming isolation steps with subsequent gas chromatographic analyses of fatty acid methyl esters. The results suggest that the pattern of astaxanthin-bound polyunsaturated fatty acids of P. borealis does not reflect the respective fatty acid pattern found in triacylglycerides. Application of the presented LC-(APCI)MS technique in common astaxanthin ester analysis will forestall erroneous xanthophyll ester assignment in natural sources. PMID:15186109

Breithaupt, Dietmar E

2004-06-16

8

Effect of brine marination on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat shrimp (Pandalus borealis).  

PubMed

The effect of brine marination at chill temperatures on survival and growth of spoilage and pathogenic bacteria during processing and subsequent storage of ready-to-eat cold water shrimp was studied. Survival and growth of Lactobacillus sakei, Listeria monocytogenes, Salmonella, Staphylococcus aureus and Vibrio parahaemolyticus were examined. The effect of brine composition and pH was determined in 12 screening experiments without addition of shrimp. Sixteen challenge tests with shrimp were then carried out to examine the effect of brine composition and storage temperature on survival and growth during processing and subsequent storage of brined and drained shrimp in modified atmosphere packaging (MAP). Different brines with (i) acetic and lactic acids (AL) or (ii) benzoic, citric and sorbic acids (BCS) were studied. V. parahaemolyticus was inactivated in brine AL without shrimp whereas concentrations of all the examined microorganisms were reduced in brine BCS. A significant effect of brine pH on inactivation was observed and inactivation during chill marination of shrimp in brine was reduced compared to the effect of brine alone. This was explained by a relatively fast increase of pH in the brine during marination of shrimp. For shrimp in brine BCS, reductions were observed for V. parahaemolyticus and Salmonella, whereas inactivation in shrimp was only noticed for Salmonella in brine AL. The observed reductions were too small to be used in practise for decontamination of shellfish. None of the examined pathogens was able to grow at 7°C in brined and drained MAP shrimp that resembled commercial products. However, reducing the concentration of acetic and lactic acids by 50% resulted in relatively fast growth of L. monocytogenes in brined and drained MAP shrimp at 7°C. Growth of S. aureus and Salmonella was observed in similar products stored at 15°C. V. parahaemolyticus was reduced in brined and drained MAP shrimp stored at both 7 and 15°C. Based on the results of the present study, L. monocytogenes was identified as the greatest potential risk with respect to the safety of brined and drained MAP shrimp. The potential of L. sakei as spoilage bacterium in brined and drained MAP shrimp was confirmed. Importantly, growth rates of L. sakei and L. monocytogenes in brined and drained MAP shrimp were predicted accurately by available mathematical models. Thus, these models can be used for product development and establishment of shell-life for ready-to-eat shrimp taking into account both quality and safety aspects. PMID:22564452

Mejlholm, Ole; Devitt, Tina D; Dalgaard, Paw

2012-06-15

9

DESCRIPTION OF LARVAE OF THE HUMPY SHRIMP, PANDALUS GONIURUS, REARED IN SITU  

E-print Network

DESCRIPTION OF LARVAE OF THE HUMPY SHRIMP, PANDALUS GONIURUS, REARED IN SITU IN KACHEMAK BAY not been verified by rearing the larvae from known parentage. Larvae ofP. goniurus were reared in situ of describing pandalid shrimp larvae reared in the laboratory from known par- entage. I have reported on larvae

10

An investigation into mechanical strength of exoskeleton of hydrothermal vent shrimp (Rimicaris exoculata) and shallow water shrimp (Pandalus platyceros) at elevated temperatures.  

PubMed

This investigation reports a comparison of the exoskeleton mechanical strength of deep sea shrimp species Rimicaris exoculata and shallow water shrimp species Pandalus platyceros at temperatures ranging from 25°C to 80°C using nanoindentation experiments. Scanning Electron Microscopy (SEM) observations suggest that both shrimp exoskeletons have the Bouligand structure. Differences in the structural arrangement and chemical composition of both shrimps are highlighted by SEM and EDX (Energy Dispersive X-ray) analyses. The variation in the elastic moduli with temperature is found to be correlated with the measured compositional differences. The reduced modulus of R. exoculata is 8.26±0.89GPa at 25°C that reduces to 7.61±0.65GPa at 80°C. The corresponding decrease in the reduced modulus of P. platyceros is from 27.38±2.3GPa at 25°C to 24.58±1.71GPa at 80°C. The decrease in reduced moduli as a function of temperature is found to be dependent on the extent of calcium based minerals in exoskeleton of both types of shrimp exoskeletons. PMID:25686945

Verma, Devendra; Tomar, Vikas

2015-04-01

11

DIET OF PACIFIC COD, GADUS MACROCEPHALUS, AND PREDATION ON THE NORTHERN PINK SHRIMp,  

E-print Network

DIET OF PACIFIC COD, GADUS MACROCEPHALUS, AND PREDATION ON THE NORTHERN PINK SHRIMp, PANDALUS BOREALIS, IN PAVLOF BAY, ALASKA W. D. ALBERS AND P. J. ANDERSON! ABSTRACf Analysis of 455 Pacific cod more frequently with increasing cod size (30-69 cm fork length). Euphausids decreased in frequency

12

FECUNDITY OF NORTHERN SHRIMp, PANDALUS BOREALIS, (CRUSTACEA, DECAPODA) IN AREAS OF  

E-print Network

.1 mm using Vernier calipers. This measurement is the distance between the posterior margin of the orbit of the eye and the posterodorsal margin of the carapace (Rasmussen 1953). All eggs were removed from

13

An investigation into environment dependent nanomechanical properties of shallow water shrimp (Pandalus platyceros) exoskeleton.  

PubMed

The present investigation focuses on understanding the influence of change from wet to dry environment on nanomechanical properties of shallow water shrimp exoskeleton. Scanning Electron Microscopy (SEM) based measurements suggest that the shrimp exoskeleton has Bouligand structure, a key characteristic of the crustaceans. As expected, wet samples are found to be softer than dry samples. Reduced modulus values of dry samples are found to be 24.90 ± 1.14 GPa as compared to the corresponding values of 3.79 ± 0.69 GPa in the case of wet samples. Hardness values are found to be 0.86 ± 0.06 GPa in the case of dry samples as compared to the corresponding values of 0.17 ± 0.02 GPa in the case of wet samples. In order to simulate the influence of underwater pressure on the exoskeleton strength, constant load creep experiments as a function of wet and dry environments are performed. The switch in deformation mechanism as a function of environment is explained based on the role played by water molecules in assisting interface slip and increased ductility of matrix material in wet environment in comparison to the dry environment. PMID:25280717

Verma, Devendra; Tomar, Vikas

2014-11-01

14

META-ANALYSIS OF COD–SHRIMP INTERACTIONS REVEALS TOP-DOWN CONTROL IN OCEANIC FOOD WEBS  

Microsoft Academic Search

Here we present a meta-analytic approach to analyzing population interac- tions across the North Atlantic Ocean. We assembled all available biomass time series for a well-documented predator-prey couple, Atlantic cod (Gadus morhua) and northern shrimp (Pandalus borealis), to test whether the temporal dynamics of these populations are con- sistent with the ''top-down'' or the ''bottom-up'' hypothesis. Eight out of nine

Boris Worm; Ransom A. Myers

2003-01-01

15

Expression Profiling without Genome Sequence Information in a Non-Model Species, Pandalid Shrimp (Pandalus latirostris), by Next-Generation Sequencing  

PubMed Central

While the study of phenotypic variation is a central theme in evolutionary biology, the genetic approaches available to understanding this variation are usually limited because of a lack of genomic information in non-model organisms. This study explored the utility of next-generation sequencing (NGS) technologies for studying phenotypic variations between 2 populations of a non-model species, the Hokkai shrimp (Pandalus latirostris; Decapoda, Pandalidae). Before we performed transcriptome analyses using NGS, we examined the genetic and phenotypic differentiation between the populations. Analyses using microsatellite DNA markers suggested that these populations genetically differed from one another and that gene flow is restricted between them. Moreover, the results of our 4-year field observations indicated that the egg traits varied genetically between the populations. Using mRNA extracted from the ovaries of 5 females in each population of Hokkai shrimp, we then performed a transcriptome analysis of the 2 populations. A total of 13.66 gigabases (Gb) of 75-bp reads was obtained. Further, 58,804 and 33,548 contigs for the first and second population, respectively, and 47,467 contigs for both populations were produced by de novo assembly. We detected 552 sequences with the former approach and 702 sequences with the later one; both sets of sequences showed greater than twofold differences in the expression levels between the 2 populations. Twenty-nine sequences were found in both approaches and were considered to be differentially expressed genes. Among them, 9 sequences showed significant similarity to functional genes. The present study showed a de novo assembly approach for the transcriptome of a non-model species using only short-read sequence data, and provides a strategy for identifying sequences showing significantly different expression levels between populations. PMID:22016807

Kawahara-Miki, Ryouka; Wada, Kenta; Azuma, Noriko; Chiba, Susumu

2011-01-01

16

Corona Borealis  

NASA Astrophysics Data System (ADS)

(the Northern Crown; abbrev. CrB, gen. Coronae Borealis; area 179 sq. deg.) A northern constellation which lies between Boötes and Hercules, and culminates at midnight in mid-May. It represents the crown that in Greek mythology was made by Hephaestus, god of fire, and worn by Princess Ariadne of Crete. Its brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest....

Murdin, P.

2000-11-01

17

The Sei Whale, Balaenoptera borealis  

E-print Network

), which makes it the third largest whale in the family Balaenopteridae, following the blue, B. musculusThe Sei Whale, Balaenoptera borealis SALLY A. MIZROCH, DALE W. RICE, and JEFFREY M. BREIWICK Introduction The sei whale, Balaenoptera borealis Lesson, 1828, can range in length up to 18.5 m (60 feet

18

NOAA Technical Report NMFS 78 August 1989 Survey of Fishes and Water Properties  

E-print Network

, by Robert A. Murchelano, Linda Despres- Patanjo, and John Ziskowski. March 1986, 14 p. 38. Fishery atlas, David S. Peters, Michael P. Seki, Richard N. Uchida, John D. Ditmars, and Robert A. Paddock. June 1986 of temperature on the biology of the northern shrimp, Pandalus borealis, in the Gulf of Maine, by Spencer

19

NOAA Technical Report NMFS 75 Codend Selection  

E-print Network

, by Robert A. Murchelano, Linda Despres- Patanjo, and John Ziskowski. March 1986, 14 p. 38. Fishery atlas, David S. Peters, Michael P. Seki, Richard N. Uchida, John D. Ditmars, and Robert A. Paddock. June 1986 oftemperarure on the biology of the northern shrimp, Pandalus borealis, in the Gulf of Maine, by Spencer

20

NOAA Technical Report NMFS 72 December 1988 Age Determination Methods for  

E-print Network

, by Robert A. Murchelano, Linda Despres- Patanjo, and John Ziskowski. March 1986, 14 p. 38. Fishery atlas, David S. Peters, Michael P. Seki, Richard N. Uchida, John D. Ditmars, and Robert A. Paddock. June 1986 of temperature on the biology of the northern shrimp, Pandalus borealis, in the Gulf of Maine, by Spencer

21

Photometry of R Coronae Borealis  

NASA Technical Reports Server (NTRS)

Visual and photoelectric observations of R Coronae Borealis are presented, including a number of observations surrounding the 1974 minimum. The recent visual history of the variable is examined and the discrete cloud obscuration model is considered.

Dawson, D. W.; Tedesco, E. F.

1976-01-01

22

Validation of the name Wolffia borealis (Lemnaceae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Problems with the valid publication of the species name Wolffia borealis, thought to have been published in 1977 for a duckweed from the United States and Canada, are discussed. The varietal name upon which W. borealis was presumably based, “W. brasiliensis var. borealis Engelm.”, did not exist in ...

23

WINDS IN CORONAE BOREALIS STARS Geoffrey Clayton,  

E-print Network

WINDS IN CORONAE BOREALIS STARS Geoffrey Clayton, 1 Geballe, Luciana Bianchi Received February accepted 2003 ABSTRACT present spectroscopic observations the i #10830 line Coronae Borealis (RCB) stars R Coronae Borealis (RCB) stars small group of hydrogen­deficient, carbon­rich supergiants

Bianchi, Luciana

24

Punching Shrimp  

NSDL National Science Digital Library

Legendary boxer Muhammad Ali used to brag that he could "float like a butterfly and sting like a bee." But to be a true champion, a prizefighter should really try to "punch like a mantis shrimp." This Science Update examines the research behind copying this mechanism for application to machinery design.

Science Update

2004-06-28

25

Nebula around R Corona Borealis  

E-print Network

The star R Corona Borealis (R CrB) shows forbidden lines of [O II], [N II], and [S II] during the deep minimum when the star is fainter by about 8 to 9 magnitudes from normal brightness, suggesting the presence of nebular material around it. We present low and high spectral resolution observations of these lines during the ongoing deep minimum of R CrB, which started in July 2007. These emission lines show double peaks with a separation of about 170 km/s. The line ratios of [S II] and [O II] suggest an electron density of about 100 cm$^{-3}$. We discuss the physical conditions and possible origins of this low density gas. These forbidden lines have also been seen in other R Coronae Borealis stars during their deep light minima and this is a general characteristic of these stars, which might have some relevance to their origins.

Rao, N Kameswara

2011-01-01

26

Brine Shrimp 1: Hatching Brine Shrimp  

NSDL National Science Digital Library

In this Science NetLinks lesson, students will design a test to determine the optimum salinity for hatching brine shrimp. In the second brine shrimp lesson of the series, students will raise these brine shrimp, designing an artificial environment in which they can survive. This lesson relates to the idea that in any particular environment, the growth and survival of organisms depend on the physical conditions.

Science Netlinks;

2001-10-20

27

Brine Shrimp 2: Brine Shrimp Survival  

NSDL National Science Digital Library

This Science NetLinks lesson is the second of two lessons on brine shrimp. In the first brine shrimp lesson, students determined the optimum salinity for hatching. In this lesson, students will raise brine shrimp, designing an artificial environment in which they can survive. This Science NetLinks lesson relates to the idea that in any particular environment, the growth and survival of organisms depend on the physical conditions.

Science Netlinks;

2001-10-20

28

SHRIMPS (ARTHROPODA: CRUSTACEA: PENAEIDAE)  

EPA Science Inventory

The pollution ecology of penaeid shrimps involving industrial organic chemicals, pesticides, petroleum, heavy metals, biological agents, and interactions of the above is discussed. Penaeid shrimps, within their geographic distribution, can serve as valid indicators of the presenc...

29

Antibacterial activity in four marine crustacean decapods  

Microsoft Academic Search

A search for antibacterial activity in different body-parts of Pandalus borealis (northern shrimp), Pagurus bernhardus (hermit crab), Hyas araneus (spider crab) and Paralithodes camtschatica (king crab) was conducted. Dried samples were extracted with 60% (v\\/v) acetonitrile, containing 0·1% (v\\/v) trifluoroacetic acid, and further extracted and concentrated on C18 cartridges. Eluates from the solid phase extraction were tested for antibacterial, lysozyme

Tor Haug; Anita K. Kjuul; Klara Stensvåg; Erling Sandsdalen; Olaf B. Styrvold

2002-01-01

30

CHARACTERIZATION OF SHRIMP BACULOVIRUS  

EPA Science Inventory

The research undertaken involved the partial characterization of a baculovirus of the pink shrimp, Penaeus duorarum. The significance of the study is related to the fact that the shrimp baculovirus is morphologically similar to insect vaculoviruses which were considered unique to...

31

R Coronae Borealis in 1992 and 1993  

Microsoft Academic Search

203 nights of UBV automatic photoelectric telescope (APT) data are reported for R Coronae Borealis in the years 1992 and 1993. An additional 21 nights of photometry from this observatory are also presented, and previously reported visual estimates are included to sketch the early stages of a deep decline at the end of the 1993 season. Through most of these

J. D. Fernie; S. Seager

1994-01-01

32

Distributed operation in the Borealis stream processing engine  

Microsoft Academic Search

Borealis is a distributed stream processing engine that is being developed at Brandeis University, Brown University, and MIT. Borealis inherits core stream processing functionality from Aurora and inter-node communication functionality from Medusa.We propose to demonstrate some of the key aspects of distributed operation in Borealis, using a multi-player network game as the underlying application. The demonstration will illustrate the dynamic

Yanif Ahmad; Bradley Berg; U?ur Cetintemel; Mark Humphrey; Jeong-Hyon Hwang; Anjali Jhingran; Anurag Maskey; Olga Papaemmanouil; Alexander Rasin; Nesime Tatbul; Wenjuan Xing; Ying Xing

2005-01-01

33

The Design of the Borealis Stream Processing Engine  

Microsoft Academic Search

Borealis is a second-generation distributed stream pro-cessing engine that is being developed at Brandeis Uni-versity, Brown University, and MIT. Borealis inherits core stream processing functionality from Aurora [14] and distribution functionality from Medusa [51]. Bo-realis modifies and extends both systems in non-trivial and critical ways to provide advanced capabilities that are commonly required by newly-emerging stream pro-cessing applications. In this

D. Abadi; Y. Ahmad; H. Balakrishnan

2004-01-01

34

Fluorine in R Coronae Borealis Stars  

Microsoft Academic Search

Neutral fluorine (F I) lines are identified in the optical spectra of several\\u000aR Coronae Borealis stars (RCBs) at maximum light. These lines provide the first\\u000ameasurement of the fluorine abundance in these stars. Fluorine is enriched in\\u000asome RCBs by factors of 800 to 8000 relative to its likely initial abundance.\\u000aThe overabundances of fluorine are evidence for the

Gajendra Pandey; David L. Lambert; N. Kameswara Rao

2007-01-01

35

Winds in R Coronae Borealis Stars  

Microsoft Academic Search

We present new spectroscopic observations of the He I $\\\\lambda$10830 line in\\u000aR Coronae Borealis (RCB) stars which provide the first strong evidence that\\u000amost, if not all, RCB stars have winds. It has long been suggested that when\\u000adust forms around an RCB star, radiation pressure accelerates the dust away\\u000afrom the star, dragging the gas along with it.

Geoffrey C. Clayton; T. R. Geballe; Luciana Bianchi

2003-01-01

36

The hybrid origin of the polyploid liverwort Pellia borealis  

Microsoft Academic Search

Isozyme markers were used to investigate the origin of the polyploid liverwort, Pellia borealis (gametophytic n=18), which was believed to represent an autopolyploid form of Pellia epiphylla (n=9). Enzyme variation was studied in four taxa: polyploid P. borealis, two recently discovered sibling species of P. epiphylla complex, and the closely related P. neesiana (n=9). Gametophytes of the polyploid showed a

Ireneusz J. Odrzykoski; Ewa Chudzifiska; Jerzy Szweykowski

1996-01-01

37

Resurfacing History of Vastitas Borealis, Mars: Early Amazonian Climate Implications  

Microsoft Academic Search

Geologic mapping of the north polar plains of Mars (>60° N.), aka Vastitas Borealis, based on Mars Orbiter Laser Altimeter (MOLA) topography, reveals new insights into resurfacing events in the polar region during the Amazonian Period. Deposits making up the Vastitas Borealis Formation (VBF) were emplaced at the end of the Hesperian Period and covered this entire region except for

K. L. Tanaka

2001-01-01

38

Two Centuries of Observing R Coronæ Borealis  

NASA Astrophysics Data System (ADS)

R Coronæ Borealis was found to be variable in the year 1783, and was one of the first variable stars to be so identified. Its class, the R Coronæ Borealis (RCB) stars, are rare hydrogen-deficient carbon-rich supergiants. RCB stars undergo massive declines of up to 8 mag due to the formation of carbon dust at irregular intervals. The mechanism of dust formation around RCB stars is not well understood, but the dust is thought to form in or near the atmosphere of the star. Their rarity may stem from the fact that they are in an extremely rapid phase of the evolution, or are in an evolutionary phase that most stars do not undergo. Several evolutionary models have been suggested to account for the RCB stars, including a merger of two white dwarfs (WDs) or a final helium-shell flash (FF) in a PN central star. The large overabundance of 18O found in most of the RCB stars favours the WD merger model, while the presence of Li in the atmospheres of five RCB stars favours the FF one. In particular, the measured isotopic abundances imply that many, if not most, RCB stars are produced by WD mergers, which may be the low-mass counterparts of the more massive mergers thought to produce type Ia supernovæ. Understanding these enigmatic stars depends to a large extent on continuous monitoring to catch their irregular but rapid variations caused by dust formation, their variations due to stellar pulsations, and long-term changes that may occur over centuries. I will use observations of R Coronæ Borealis obtained over 200 years to demonstrate what kinds of monitoring are necessary for these and similar classes of variables.

Clayton, Geoffrey C.

2012-04-01

39

Fluorine in R Coronae Borealis Stars  

E-print Network

Neutral fluorine (F I) lines are identified in the optical spectra of several R Coronae Borealis stars (RCBs) at maximum light. These lines provide the first measurement of the fluorine abundance in these stars. Fluorine is enriched in some RCBs by factors of 800 to 8000 relative to its likely initial abundance. The overabundances of fluorine are evidence for the synthesis of fluorine. These results are discussed in the light of the scenario that RCBs are formed by accretion of an He white dwarf by a C-O white dwarf. Sakurai's object (V4334 Sgr), a final He-shell flash product, shows no detectable F I lines.

Gajendra Pandey; David L. Lambert; N. Kameswara Rao

2007-11-15

40

Fluorine in R Coronae Borealis Stars  

E-print Network

Neutral fluorine (F I) lines are identified in the optical spectra of several R Coronae Borealis stars (RCBs) at maximum light. These lines provide the first measurement of the fluorine abundance in these stars. Fluorine is enriched in some RCBs by factors of 800 to 8000 relative to its likely initial abundance. The overabundances of fluorine are evidence for the synthesis of fluorine. These results are discussed in the light of the scenario that RCBs are formed by accretion of an He white dwarf by a C-O white dwarf. Sakurai's object (V4334 Sgr), a final He-shell flash product, shows no detectable F I lines.

Pandey, Gajendra; Rao, N Kameswara

2007-01-01

41

Diapause traits in Melanoplus sanguinipes and M. borealis (Orthoptera: Acrididae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

A thorough understanding of diapause is needed for prediction of population responses to climate change, for realistic simulation models, and for the development of effective pest management. In Melanoplus sanguinipes (Fabricius) and M. borealis (Fieber) (Orthoptera: Acrididae), diapause typically o...

42

The Design of the Borealis Stream Processing Engine  

Microsoft Academic Search

Borealis is a second-generation distributed stream pro- cessing engine that is being developed at Brandeis Uni- versity, Brown University, and MIT. Borealis inherits core stream processing functionality from Aurora (14) and distribution functionality from Medusa (51). Bo- realis modifies and extends both systems in non-trivial and critical ways to provide advanced capabilities that are commonly required by newly-emerging stream pro-

Daniel J. Abadi; Yanif Ahmad; Magdalena Balazinska; Ugur Çetintemel; Mitch Cherniack; Jeong-hyon Hwang; Wolfgang Lindner; Anurag Maskey; Alex Rasin; Esther Ryvkina; Nesime Tatbul; Ying Xing

2005-01-01

43

Color Control in Shrimp  

NSDL National Science Digital Library

Sand shrimp, Crangon septemspinosus, are capable of varying their color or shading in response to several environmental changes (background color, light intensity, light wavelength, and temperature). The degree of color change can be determined quantitatively by examining the chromatophores under a dissecting microscope and staging the amount of pigment dispersion, (b) the location or type of receptors involved, and (c) the type of communication between receptors and effectors.

Mary-Jane O'Halloran (Dalhousie University; )

1989-06-06

44

R Coronae Borealis stars and planetary nebulae  

NASA Technical Reports Server (NTRS)

IRAS observations of R Coronae Borealis type stars (R CrB's) suggests that a subset of these is inside planetary nebulae (PNs). In most cases, the PN is confirmed by the finding of a visible nebula around the star. These nebular R CrB's are identified as being the results of a final helium shell flash on the central star of old PNs. The majority of the R CrB's formed after the coalescence of a binary consisting of CO and He white dwarfs. Also presented in this paper are the results of a survey of 52 R CrB's. The normal R CrB's have power-law spectra which imply that the grain absorption coefficient varies linearly with frequency. It is estimated that R CrB's eject about 300 clouds per year, each of which subtend an angle of about 30 sq deg.

Schaefer, B. E.

1986-01-01

45

Substrate Selection by Ghost Shrimp  

NSDL National Science Digital Library

The purpose of this experiment is to determine if ghost shrimp show a preference for a particular substrate surface under artificial conditions. Ghost shrimp are geographically widespread. They are an important source of food for many fish, mammals, and birds. Ghost shrimp are omnivorous, seldom predaceous. Their preferred food is aquatic vegetation. Ecologically, they are considered scavengers. Therefore, they contribute to an efficient flow of energy within aquatic habitats. Economically, they have become a favorite source of live food for aquarium fish and are sold in pet stores and are harvested for bait for sport fishing.

Ms. Sue Diggs (Monterey High School)

2000-07-01

46

What Are the R Coronae Borealis Stars?  

NASA Astrophysics Data System (ADS)

The R Coronae Borealis (RCB) stars are rare hydrogen-deficient, carbon-rich, supergiants, best known for their spectacular declines in brightness at irregular intervals. Efforts to discover more RCB stars have more than doubled the number known in the last few years and they appear to be members of an old, bulge population. Two evolutionary scenarios have been suggested for producing an RCB star, a double degenerate merger of two white dwarfs, or a final helium shell flash in a planetary nebula central star. The evidence pointing toward one or the other is somewhat contradictory, but the discovery that RCB stars have large amounts of 18O has tilted the scales towards the merger scenario. If the RCB stars are the product of white dwarf mergers, this would be a very exciting result since RCB stars would then be low-mass analogs of type Ia supernovae. The predicted number of RCB stars in the Galaxy is consistent with the predicted number of He/CO WD mergers. But, so far, only about sixty-five of the predicted 5,000 RCB stars in the Galaxy have been discovered. The mystery has yet to be solved.

Clayton, G. C.

2012-06-01

47

The dynamics of the Corona Borealis supercluster  

NASA Technical Reports Server (NTRS)

The dynamics of the Corona Borealis (Cor Bor) supercluster was studied on a sample of 1555 galaxies in the vicinity of the six Abell clusters (A2061, A2065, A2067, A2079, A2089, and A2092) which comprise the supercluster. For all galaxies in this sample, photographic R photometry and accurate positional data are available. New R photometry and/or new redshifts were obtained for 97 galaxies, bringing the number of galaxies in this system for which the redshifts are available to 182. The central cluster R band luminosity, X-ray luminosity, and surface density were correlated with the cluster velocity dispersion and virial mass. The amount of matter in the supercluster, estimated to be about 8.2 x 10 to the 15th solar masses, is considered to be sufficient to bind the six Cor Bor clusters, which are contained within a volume of about 13 Mpc in radius. Dynamical time scales are comparable with the Hubble time, making it unlikely that the system is virialized.

Postman, M.; Geller, M. J.; Huchra, J. P.

1988-01-01

48

What are the R Coronae Borealis Stars?  

E-print Network

The R Coronae Borealis (RCB) stars are rare hydrogen-deficient, carbon-rich, supergiants, best known for their spectacular declines in brightness at irregular intervals. Efforts to discover more RCB stars have more than doubled the number known in the last few years and they appear to be members of an old, bulge population. Two evolutionary scenarios have been suggested for producing an RCB star, a double degenerate merger of two white dwarfs, or a final helium shell flash in a planetary nebula central star. The evidence pointing toward one or the other is somewhat contradictory, but the discovery that RCB stars have large amounts of 18O has tilted the scales towards the merger scenario. If the RCB stars are the product of white dwarf mergers, this would be a very exciting result since RCB stars would then be low-mass analogs of type Ia supernovae. The predicted number of RCB stars in the Galaxy is consistent with the predicted number of He/CO WD mergers. But, so far, only about 65 of the predicted 5000 RCB s...

Clayton, Geoffrey C

2012-01-01

49

Monodon baculovirus of shrimp.  

PubMed

Among the viruses infecting penaeid shrimp, monodon-type baculovirus (MBV) otherwise known as Penaeus monodon singly enveloped nuclear polyhedrosis virus (PmSNPV), is one of the widely reported and well described viruses. It is a rod-shaped, enveloped, double-stranded DNA virus, and considered till recently, as the type A baculovirus. Besides MBV, two strains of SNPV are reported-plebejus baculovirus and bennettae baculovirus. MBV was reported to be originated from Taiwan and has wide geographic distribution and is reported to be enzootic in wild penaeids of the Indo-pacific coasts of Asia. The virus also has diverse host-range including a variety of cultured and captured shrimp species and freshwater prawn, Macrobrachium rosenbergii. MBV has been reported in all life stages of P. monodon with late larval, postlarval and young juvenile as the most susceptible stages/ages. However, MBV has not been documented in early larval stages. Although MBV has been reported to be tolerated well by shrimp, the infection has been attributed to decreased productivity. The target organs or tissues of MBV are the hepatopancreatic tubules and duct epithelium of postlarvae, juveniles and adults, and the anterior midgut epithelium of very young postlarvae. The prominent clinical sign of infection is the presence of multiple spherical inclusion bodies in the hepatopancreas and midgut epithelial cells. The major mode of transmission of the virus is horizontal through oral exposure to occlusion bodies, contaminated tissues or fomites. Minor morphometric variation of the virus has been reported among different isolates. The rod-shaped enveloped virus particles range from 265-324 nm in length and 42-77 nm in diameter. Although complete genome sequence of MBV is not available, nucleic acid of MBV is circular, double-stranded DNA with a genome size ranging from 80 to 160 kbp. The virus codes for a 53 kDa major polyhedrin polypeptide and two minor 47 and 49 kDa polypeptides. A variety of diagnostic tools have been reported for this virus including real-time PCR and LAMP-based detection. Taxonomic position is still uncertain and International Committee on Taxonomy of Viruses lists MBV as a tentative species named PemoNPV in the genus Nucleopolyhedrovirus. However, according to the latest genomic information on the virus, it has been suggested to create a new group of non-occluded bacilliform viruses called nudiviruses with MBV as one of the members. The aim of the current work is to describe the knowledge on the status, distribution and host-range, pathology, transmission, virus structure and morphogenesis, genomic characteristics, diagnosis and the latest taxonomic position of MBV. PMID:23997439

Rajendran, K V; Makesh, M; Karunasagar, I

2012-09-01

50

Science Nation: Disappearing Red Shrimp  

NSDL National Science Digital Library

Along the shore in Hawaii, the ponds imbedded in lava rocks contain organisms found only in that environment. Among the marine life in these pools are hundreds of tiny red shrimp. With support from the National Science Foundation (NSF), molecular biologist Scott Santos and his team at Auburn University are studying how the shrimp, along with other organisms, thrive in harsh, brackish pools of water.

51

On the Feeding Mechanisms of the Sei Whale ( Balaenoptera borealis )  

Microsoft Academic Search

The sei whale (Balaenoptera borealis) is a medium sized rorqual with basic features similar to the larger fin and blue (Balaenoptera sp.). While the sei whale has an expandable buccal pouch, it's capacity is substantially reduced by the length of the ventral grooves relative to fin and blue whales. The finer filtration capacity of the baleen allows predation on smaller

P. Brodie; G. Vikingsson

2010-01-01

52

ES Aquilae Is an R Coronae Borealis Star  

Microsoft Academic Search

ES Aql, initially classified as a semiregular variable, is now believed to be a member of the R Coronae Borealis (RCB) class of stars, a small group of carbon-rich supergiants that undergo dramatic declines in brightness at irregular intervals. We present photometry of ES Aql going back as far as 1893 using plates from the Harvard College Observatory as well

Geoffrey C. Clayton; D. Hammond; J. Lawless; D. Kilkenny; T. Lloyd Evans; J. Mattei; A. U. Landolt

2002-01-01

53

Chemical composition of R Coronae Borealis and XX Camelopardalis  

Microsoft Academic Search

Three R Coronae Borealis stars (R CrB, XX Cam, and RY Sgr) have been examined using extensive, high resolution, high signal-to-noise Reticon data. From He- and C-rich models and an appropriate model atmosphere code, the following atmospheric parameters were derived

P. L. Cottrell; D. L. Lambert

1982-01-01

54

on red-cockaded woodpecker Picoides borealis reproductive success  

Microsoft Academic Search

Anecdotal data gathered from many populations suggest that southern flying squirrel (SFS, Gluucomys volans) use of the endangered red-cockaded woodpecker's (RCW, Picoides borealis) nest and roost cavities may negatively affect RCW populations. We conducted a controlled experiment to determine the effects of SFSs on RCW reproductive success. During the 1994 and 1995 breeding seasons, SFSs were removed from 30 RCW

Kevin S. Laves; Susan C. Loeb

55

The Aurora and Borealis Stream Processing Ugur Cetintemel1  

E-print Network

The Aurora and Borealis Stream Processing Engines Ugur C¸etintemel1 , Daniel Abadi2 , Yanif Ahmad1 on an SPE. The Aurora stream-processing engine, motivated by these three tenets, is currently operational-shedding algorithms are presented in [18], and our approach to high availability in a multi-site Aurora installation

Balazinska, Magdalena

56

Winds in R Coronae Borealis Stars  

E-print Network

We present new spectroscopic observations of the He I $\\lambda$10830 line in R Coronae Borealis (RCB) stars which provide the first strong evidence that most, if not all, RCB stars have winds. It has long been suggested that when dust forms around an RCB star, radiation pressure accelerates the dust away from the star, dragging the gas along with it. The new spectra show that nine of the ten stars observed have P-Cygni or asymmetric blue-shifted profiles in the He I $\\lambda$10830 line. In all cases, the He I line indicates a mass outflow - with a range of intensity and velocity. Around the RCB stars, it is likely that this state is populated by collisional excitation rather than photoionization/recombination. The line profiles have been modeled with an SEI code to derive the optical depth and the velocity field of the helium gas. The results show that the typical RCB wind has a steep acceleration with a terminal velocity of \\Vinf = 200-350 \\kms and a column density of N $\\sim10^{12}$ cm$^{-2}$ in the He I $\\lambda$10830 line. There is a possible relationship between the lightcurve of an RCB star and its He I $\\lambda$10830 profile. Stars which have gone hundreds of days with no dust-formation episodes tend to have weaker He I features. The unusual RCB star, V854 Cen, does not follow this trend, showing little or no He I absorption despite high mass-loss activity. The He I $\\lambda$10830 line in R CrB itself, which has been observed at four epochs between 1978 and 2001, seems to show a P-Cygni or asymmetric blue-shifted profile at all times whether it is in decline or at maximum light.

Geoffrey C. Clayton; T. R. Geballe; Luciana Bianchi

2003-06-04

57

CONJOINED TWIN ADULT SHRIMP (DECAPODA: PENAEIDAE)  

E-print Network

NOTES CONJOINED TWIN ADULT SHRIMP (DECAPODA: PENAEIDAE) A two-headed roughback shrimp by preservation. Antennules, anten- FIGURE I.-Conjoined twin Trackype1UUi'1U1 simi/is in diagrammatic lateral view

58

???????????????????????????????????????????? Design and Development of Shrimp Straightening Machine  

Microsoft Academic Search

A semi automatic shrimp straightening machine controlled by a programmable logic controller (PLC) was designed and developed. The machine consisted of three main parts, a shrimp conveyor, a shrimp pressing straightening part and the controller. The machine had three operation steps. In the first step, a pneumatic cylinder retreated at the stroke of 5 cm to move the conveyor with

Prakarn Paemunkong

59

The Newly Active R Coronae Borealis Star, V2552 Oph  

E-print Network

In 2001, V2552 Oph (CD -22 12017, HadV98) quickly faded by several magnitudes in a manner typical of the R Coronae Borealis (RCB) stars. Photometry of V2552 Oph obtained over 70 years previous to 2001 shows no indication of variability. Optical spectra of this star subsequently confirmed that V2552 Oph is a member of the hydrogen deficient, carbon-rich RCB class of variables. It resembles the warm (T$_{eff}\\sim$ 7000 K) RCB stars such as R Coronae Borealis itself. Other RCB stars, such as XX Cam and Y Mus, have experienced similar periods of inactivity, going decades without significant dust formation. Further observations of V2552 Oph will be of great interest since there is an opportunity to monitor an RCB star that may be moving from prolonged inactivity into an active phase of dust production.

E. Hesselbach; Geoffrey C. Clayton; Paul S. Smith

2003-09-11

60

The R Coronae Borealis stars — A few mere facts  

Microsoft Academic Search

This review presents a selection of recent highlights of observations of R Coronae Borealis variables. Emphasis is placed\\u000a on an abundance analysis of a complete sample (18 stars) of the warm galactic RCBs. It is shown that 14 of the 18 have very\\u000a similar compositions: the iron mass fraction ranges about a factor of 3 around the solar value (assuming

David L. Lambert; N. Kameswara Rao

1994-01-01

61

The Newly Active R Coronae Borealis Star, V2552 Oph  

Microsoft Academic Search

In 2001, V2552 Oph (CD -22 12017, HadV98) quickly faded by several magnitudes\\u000ain a manner typical of the R Coronae Borealis (RCB) stars. Photometry of V2552\\u000aOph obtained over 70 years previous to 2001 shows no indication of variability.\\u000aOptical spectra of this star subsequently confirmed that V2552 Oph is a member\\u000aof the hydrogen deficient, carbon-rich RCB class

E. Hesselbach

2003-01-01

62

The R Coronae Borealis stars - atmospheres and abundances  

Microsoft Academic Search

An abundance analysis of the H-deficient and He- and C-rich R Coronae Borealis (R CrB) stars has been under- taken to examine the ancestry of the stars. The investigation is based on high-resolution spectra and line-blanketed H-deficient model atmospheres. The models successfully reproduce the flux distributions and all spectral features, both molecular bands and high-excitation transitions, with one important exception,

M. Asplund; B. Gustafsson; D. L. Lambert; N. K. Rao

2000-01-01

63

Polarization signals in mantis shrimps  

NASA Astrophysics Data System (ADS)

While color signals are well known as a form of animal communication, a number of animals communicate using signals based on patterns of polarized light reflected from specialized body parts or structures. Mantis shrimps, a group of marine crustaceans, have evolved a great diversity of such signals, several of which are based on photonic structures. These include resonant scattering devices, structures based on layered dichroic molecules, and structures that use birefringent layers to produce circular polarization. Such biological polarizers operate in different spectral regions ranging from the near-UV to medium wavelengths of visible light. In addition to the structures that are specialized for signal production, the eyes of many species of mantis shrimp are adapted to detect linearly polarized light in the ultraviolet and in the green, using specialized sets of photoreceptors with oriented, dichroic visual pigments. Finally, a few mantis shrimp species produce biophotonic retarders within their photoreceptors that permit the detection of circularly polarized light and are thus the only animals known to sense this form of polarization. Mantis shrimps use polarized light in species-specific signals related to mating and territorial defense, and their means of manipulating light's polarization can inspire designs for artificial polarizers and achromatic retarders.

Cronin, Thomas W.; Chiou, Tsyr-Huei; Caldwell, Roy L.; Roberts, Nicholas; Marshall, Justin

2009-08-01

64

21 CFR 161.176 - Frozen raw lightly breaded shrimp.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Frozen raw lightly breaded shrimp. 161.176 Section 161.176 Food and Drugs ...Fish and Shellfish § 161.176 Frozen raw lightly breaded shrimp. Frozen raw lightly breaded shrimp...

2011-04-01

65

21 CFR 161.176 - Frozen raw lightly breaded shrimp.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Frozen raw lightly breaded shrimp. 161.176 Section 161.176 Food and Drugs ...Fish and Shellfish § 161.176 Frozen raw lightly breaded shrimp. Frozen raw lightly breaded shrimp...

2010-04-01

66

Potential and realized rates of vegetative reproduction in Spirodela polyrhiza, Lemna minor, and Wolffia borealis  

Microsoft Academic Search

The rate of vegetative propagule development was estimated in three duckweed (Lemnaceae) species, Spirodela polyrhiza, Lemna minor, and Wolffia borealis, by measuring the number of daughter fronds produced over the life span of mother fronds. Under the same constant environmental conditions, plants of L. minor lived the longest (31.3 days) and produced the most daughter fronds (14.0), yet W. borealis

Gordon D. Lemon; Usher Posluszny; Brian C. Husband

2001-01-01

67

The Norris Survey of the Corona Borealis Supercluster. III. Structure and Mass of the Supercluster  

Microsoft Academic Search

We present a study of the structure and dynamics of the Corona Borealis supercluster (z ~ 0.07) based on the redshifts of 528 galaxies in the supercluster. The galaxy distribution within Corona Borealis is clumpy and appears overall to be far from relaxed. Approximately one-third of the supercluster galaxies lie outside of the Abell clusters in the supercluster. A background

Todd A. Small; Chung-Pei Ma; Wallace L. W. Sargent; Donald Hamilton

1998-01-01

68

Arsenic in shrimp from Kuwait  

SciTech Connect

Arsenic is ubiquitous in the environment and can accumulate in food via contaminated soil, water or air. It enters the food chain through dry and wet atmospheric deposition. Combustion of oil and coal, use of arsenical fertilizers and pesticides and smelting of ores contributes significantly to the natural background of arsenic in soils and sediments. The metal can be transferred from soil to man through plants. In spite of variation in acute, subacute, and chronic toxic effects to plants and animals, evidence of nutritional essentiality of arsenic for rats, goats, and guinea pigs has been suggested, but has not been confirmed for humans. Adverse toxic effects of arsenic as well as its widespread distribution in the environment raises concern about levels of arsenic in man`s diet. Higher levels of arsenic in the diet can result in a higher accumulation rate. Arsenic levels in marine organisms are influenced by species differences, size of organism, and human activities. Bottom dwellers such as shrimp, crab, and lobster accumulate more arsenic than fish due to their frequent contact with bottom sediments. Shrimp constitute approximately 30% of mean total seafood consumption in Kuwait. This study was designed to determine the accumulation of arsenic in the commercially important jinga shrimp (Metapenaeus affinis) and grooved tiger prawn (Penaeus semisulcatus). 13 refs., 3 figs., 1 tab.

Bou-Olayan, A.H. [Kuwait Univ. (Kuwait); Al-Yakoob, S.; Al-Hossaini, M. [Kuwait Institute for Scientific Research (Kuwait)

1995-04-01

69

Optical Spectroscopy at Deep Light Minimum of R Coronae Borealis  

NASA Astrophysics Data System (ADS)

We present optical spectroscopy late in a deep minimum for the quintessential hydrogen-deficient carbon star R Coronae Borealis. Starting 3.5 years into the current deep and long minimum, we have secured observations that reveal some of the oddest optical spectra ever obtained for any astronomical object. Helium emission lines from triplet transitions, strong Ca II H and K emission, and forbidden lines of oxygen and nitrogen are the only spectral features observed. The spectra can be interpreted as coming from a chromospheric-like region lying above a carbon shell ejection front combined with a large-scale nebular-like region surrounding the star.

Howell, Steve B.; Rector, Travis A.; Walter, Donald

2013-08-01

70

Fluorine in R Coronae Borealis and Extreme Helium Stars  

E-print Network

Neutral fluorine lines are identified in the optical spectra of several R Coronae Borealis stars (RCBs) at maximum light. These lines provide the first measurement of the fluorine abundance in these stars. Fluorine is enriched in some RCBs by factors of 800 to 8000 relative to its likely initial abundance. The overabundances of fluorine are evidence for the synthesis of fluorine. These results are discussed in the light of the scenario that RCBs are formed by accretion of an He white dwarf by a C-O white dwarf. Sakurai's object (V4334 Sgr), a final He-shell flash product, shows no detectable neutral fluorine lines.

Gajendra Pandey; David L. Lambert; N. Kameswara Rao

2007-12-24

71

R Coronae Borealis dust ejections - A preferred plane?  

NASA Technical Reports Server (NTRS)

Spectropolarimetric observations of R Coronae Borealis obtained during the brightness minimum of 1986 are presented. When combined with previous polarization observations of brightness minima, the distribution of observations in the Q-U plane suggests that ejections of dust clouds occur in a preferred plane about the star, in contrast to the standard model for the R CrB-type stars, which holds that clouds are ejected from all parts of the stellar surface. The possibility of an ejection mechanism connected with nonradial pulsations is discussed as the most likely explanation of the preferred plane.

Stanford, S. A.; Clayton, G. C.; Meade, M. R.; Nordsieck, K. H.; Whitney, B. A.

1988-01-01

72

Fluorine in R Coronae Borealis and Extreme Helium Stars  

E-print Network

Neutral fluorine lines are identified in the optical spectra of several R Coronae Borealis stars (RCBs) at maximum light. These lines provide the first measurement of the fluorine abundance in these stars. Fluorine is enriched in some RCBs by factors of 800 to 8000 relative to its likely initial abundance. The overabundances of fluorine are evidence for the synthesis of fluorine. These results are discussed in the light of the scenario that RCBs are formed by accretion of an He white dwarf by a C-O white dwarf. Sakurai's object (V4334 Sgr), a final He-shell flash product, shows no detectable neutral fluorine lines.

Pandey, Gajendra; Rao, N Kameswara

2007-01-01

73

On the Abundance of Lithium in T Coronae Borealis  

NASA Technical Reports Server (NTRS)

We have obtained high resolution echelle spectroscopy of the recurrent nova T CrB (T Coronae Borealis). We find that the surface lithium abundance in T CrB is significantly enhanced compared to field M giants, where it is not detectable. We offer possible explanations for this in terms of either a delay in the onset of convection in the giant star, enhanced coronal activity due to star-spots or the enhancement of Li resulting from the nova explosion(s).

Shahbaz, T.; Hauschildt, P.H.; Naylor, T.; Ringwald, F.

1999-01-01

74

STS-56 remote manipulator system (RMS) backdropped against Aurora Borealis  

NASA Technical Reports Server (NTRS)

STS-56 remote manipulator system (RMS) arm is backdropped against the 'northern lights' (Aurora Borealis) in this view exposed from the crew cabin of Discovery, Orbiter Vehicle (OV) 103. The arm was used in operations with the Shuttle Pointed Autonomous Research Tool for Astronomy 201 (SPARTAN-201). Space Shuttle astronauts have the opportunity to observe auroral activity only on 57-degree inclination missions and only in the 'night' hemisphere. Astronaut hand-held photography is the only method which is capable of documenting the detailed structure of the auroral oval.

1993-01-01

75

A comparison of host-defense peptides in skin secretions of female Xenopus laevis × Xenopus borealis and X. borealis × X. laevis F1 hybrids.  

PubMed

Peptidomic analysis was used to compare the diversity of host-defense peptides in norepinephrine-stimulated skin secretions from laboratory-generated female F1 hybrids of Xenopus laevis and Xenopus borealis (Pipidae). Skin secretions of hybrids with maternal X. laevis (XLB) contained 12 antimicrobial peptides (AMPs), comprising 8 from X. laevis and 4 from X. borealis. Magainin-B1, XPF-B1, PGLa-B1 CPF-B2, CPF-B3 and CPF-B4 from X. borealis and XPF-1, XPF-2, and CPF-6 from X. laevis were not detected and CPF-1 and CPF-7 were present in low concentration. The secretions contained caerulein and caerulein-B1 derived from both parents but lacked X. laevis xenopsin and X. borealis caerulein-B2. Skin secretions of hybrids with maternal X. borealis (XBL) contained 14 AMPs comprising 6 from X. borealis and 8 from X. laevis. Magainin-B1, XPF-B1, PGLa-B1, CPF-B2, XPF-1, CPF-5, and CPF-7 were absent and CPF-B3, CPF-B4, CPF-1 and CPF-6 were present only in low concentration. Xenopsin and caerulein were identified in the secretions but caerulein-B2 was absent and caerulein-B1 was present in low concentration. No peptides were identified in secretions of either XLB or XBL hybrids that were not present in the parental species. The data indicate that hybridization between X. laevis and X. borealis results in increased diversity of host-defense peptides in skin secretions but point to extensive AMP gene silencing compared with previously studied female X. laevis×X. muelleri F1 hybrids and no novel peptide expression. PMID:23624316

Mechkarska, Milena; Prajeep, Manju; Leprince, Jérôme; Vaudry, Hubert; Meetani, Mohammed A; Evans, Ben J; Conlon, J Michael

2013-07-01

76

Migration and molt patterns of red bats, Lasiurus borealis (Chiroptera: Vespertilionidae), in Illinois  

E-print Network

Red bats, Lasiurus borealis (Chiroptera: Vespertilionidae), are widespread in North America, but many aspects of their biology are poorly known. In an attempt to elucidate patterns of migration and molt in red bats, data were collected over...

Timm, Robert M.

1989-01-01

77

Topographic and Roughness Characteristics of the Vastitas Borealis Formation on Mars Described by Fractal Statistics  

NASA Technical Reports Server (NTRS)

The surface roughness of the Vastitas Borealis Formation on Mars was analyzed with fractal statistics. Root mean square slopes and fractal dimensions were calculated for 74 topographic profiles. Results have implications for radar scattering models.

Garneau, S.; Plaut, J. J.

2000-01-01

78

5. Aurora Borealis Pass over the United States at Night - Duration: 0:21.  

NASA Video Gallery

This video of the United States at night and the Aurora Borealis was taken by the crew of Expedition 29 on board the International Space Station. This sequence of shots was taken September 29, 2011...

79

Distribution of Boroecia borealis (Ostracoda: Halocyprididae) in the Arctic Ocean and adjacent waters of the Atlantic  

Microsoft Academic Search

The geographical and vertical distribution of Boroecia borealis was studied based on literature data and materials collected by Soviet and Russian expeditions in the Arctic Ocean and adjacent\\u000a waters of the Atlantic during the period from 1929 to 1993. In the region of study, this species occurs at a temperature from\\u000a 0.5 to 17.7°C. In the Arctic basin, B. borealis

A. G. Bashmanov; V. G. Chavtur

2008-01-01

80

Probiotics as Antiviral Agents in Shrimp Aquaculture  

PubMed Central

Shrimp farming is an aquaculture business for the cultivation of marine shrimps or prawns for human consumption and is now considered as a major economic and food production sector as it is an increasingly important source of protein available for human consumption. Intensification of shrimp farming had led to the development of a number of diseases, which resulted in the excessive use of antimicrobial agents, which is finally responsible for many adverse effects. Currently, probiotics are chosen as the best alternatives to these antimicrobial agents and they act as natural immune enhancers, which provoke the disease resistance in shrimp farm. Viral diseases stand as the major constraint causing an enormous loss in the production in shrimp farms. Probiotics besides being beneficial bacteria also possess antiviral activity. Exploitation of these probiotics in treatment and prevention of viral diseases in shrimp aquaculture is a novel and efficient method. This review discusses the benefits of probiotics and their criteria for selection in shrimp aquaculture and their role in immune power enhancement towards viral diseases. PMID:23738078

Lakshmi, Bestha; Sai Gopal, D. V. R.

2013-01-01

81

78 FR 15691 - Certain Frozen Warmwater Shrimp From India; Preliminary Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From India; Preliminary Results of Antidumping Duty...frozen warmwater shrimp (shrimp) from India. The review covers 195 producers/ exporters...Certain Frozen Warmwater Shrimp From India, 77 FR 73619 (December 11,...

2013-03-12

82

77 FR 40848 - Certain Frozen Warmwater Shrimp From India: Final Results of Antidumping Duty Administrative...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From India: Final Results of Antidumping Duty Administrative...frozen warmwater shrimp (shrimp) from India. The period of review (POR) is February...the antidumping duty order on shrimp from...

2012-07-11

83

Microbial flora of fresh and stored shrimp  

E-print Network

, 700 480&000 720, 000 190, 000 170, 000 Shrimp was stored at 1 C for 7 days Table 6. Aerobic and anaerobic plate counts of fresh and stored shrimp sample 6 on plate count aSar prepared with different waters Shrimp Sample Conditions of plate... throughout this study. This project was partially funded by the National Science Foundation Sea Grant Program, Institutional Grant GH-59 made to Texas A&M University. TABLE OF CONTENTS INTRODUCTION P~ae REVIEN OF LITERATURE 1%TERIALS AND METHODS' ~ e...

Mroz, Eva

1970-01-01

84

NPOI Observations of the Exoplanet Host Kappa Coronae Borealis  

NASA Astrophysics Data System (ADS)

Kappa Coronae Borealis is a "retired A star", otherwise known as a former A-type dwarf that is now a K-type subgiant. It is a particularly fascinating target because of its unusual configuration of companions and dust rings. It hosts at least one exoplanet and perhaps two, and features a single wide dust ring or two narrow ones. We observed the star interferometrically in order to characterize the main star and the environment in which the planet(s) and dust ring(s) reside. We determined a variety of fundamental parameters for kappa CrB: the limb-darkened angular diameter, physical size, effective temperature, luminosity, mass, age, and the extent of the habitable zone range. We combined our mass with the orbital parameters from four sources from the literature to calculate the planet's mass as well.

Baines, Ellyn K.; Armstrong, J. T.; van Belle, G.

2014-01-01

85

Mid-Infrared Variations of R Coronae Borealis Stars  

E-print Network

Mid-infrared photometry of R Coronae Borealis stars obtained from various satellites from IRAS to WISE has been utilized in studying the variations of the circumstellar dust's contributions to the spectral energy distribution of these stars. The variation of the fractional coverage (R) of dust clouds and their blackbody temperatures (T$_d$) have been used in trying to understand the dust cloud evolution over the three decades spanned by the satellite observations. In particular, it is shown that a prediction R $ \\propto T_d^4$ developed in this paper is satisfied, especially by those stars for which a single collection of cloud dominates the IR fluxes. Correlations of R with photospheric abundance and luminosity of the stars are explored.

Rao, N Kameswara

2014-01-01

86

A Dynamical Analysis of the Corona Borealis Supercluster  

E-print Network

Using data from the Sloan Digital Sky Survey we assess the current dynamical state of the Corona Borealis Supercluster (CSC), a highly dense and compact supercluster at z = 0.07. The Fundamental Plane relation is used to determine redshift independent distances to six clusters in the densest region of the supercluster, with mean accuracy in the relative distance estimates of 4 per cent. Peculiar velocities determined from these distance estimates indicate that the clusters have broken from the Hubble Flow, suggesting that the CSC likely contains two regions that have reached turnaround and are currently undergoing gravitational collapse. These results provide the strongest observational evidence to date that the CSC is a bound system similar to the much more extensive Shapley Supercluster, which is the most extensive confirmed bound supercluster yet identified in the Universe. When compared with simulations of the CSC our results require substantially more mass than is contained within the clusters, possibly ...

Batiste, Merida

2013-01-01

87

Variable Winds and Dust Formation in R Coronae Borealis Stars  

E-print Network

We have observed P-Cygni and asymmetric, blue-shifted absorption profiles in the He I 10830 lines of twelve R Coronae Borealis (RCB) stars over short (1 month) and long (3 year) timescales to look for variations linked to their dust-formation episodes. In almost all cases, the strengths and terminal velocities of the line vary significantly and are correlated with dust formation events. Strong absorption features with blue-shifted velocities ~400 km/s appear during declines in visible brightness and persist for about 100 days after recovery to maximum brightness. Small residual winds of somewhat lower velocity are present outside of the decline and recovery periods. The correlations support models in which recently formed dust near the star is propelled outward at high speed by radiation pressure and drags the gas along with it.

Clayton, Geoffrey C; Zhang, Wanshu

2013-01-01

88

Variable Winds and Dust Formation in R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

We have observed P-Cygni and asymmetric, blue-shifted absorption profiles in the He I ?10830 lines of 12 R Coronae Borealis stars over short (1 month) and long (3 yr) timescales to look for variations linked to their dust-formation episodes. In almost all cases, the strengths and terminal velocities of the line vary significantly and are correlated with dust formation events. Strong absorption features with blue-shifted velocities ~400 km s-1 appear during declines in visible brightness and persist for about 100 days after recovery to maximum brightness. Small residual winds of somewhat lower velocity are present outside of the decline and recovery periods. The correlations support models in which recently formed dust near the star is propelled outward at high speed by radiation pressure and drags the gas along with it.

Clayton, Geoffrey C.; Geballe, T. R.; Zhang, Wanshu

2013-08-01

89

R Coronae Borealis Stars at Minimum Light -- UW Cen  

E-print Network

Two high-resolution optical spectra of the R Coronae Borealis star UW Cen in decline are discussed. A spectrum from mid-1992 when the star had faded by three magnitudes shows just a few differences with the spectrum at maximum light. The ubiquitous sharp emission lines seen in R CrB at a similar drop below maximum light are absent. In contrast, a spectrum from mid-2002 when the star was five magnitudes below maximum light shows an array of sharp emission lines and a collection of broad emission lines. Comparisons are made with spectra of R CrB obtained during the deep 1995-1996 minimum. The many common features are discussed in terms of a torus-jet geometry.

N. Kameswara Rao; B. E. Reddy; D. L. Lambert

2004-09-09

90

VARIABLE WINDS AND DUST FORMATION IN R CORONAE BOREALIS STARS  

SciTech Connect

We have observed P-Cygni and asymmetric, blue-shifted absorption profiles in the He I {lambda}10830 lines of 12 R Coronae Borealis stars over short (1 month) and long (3 yr) timescales to look for variations linked to their dust-formation episodes. In almost all cases, the strengths and terminal velocities of the line vary significantly and are correlated with dust formation events. Strong absorption features with blue-shifted velocities {approx}400 km s{sup -1} appear during declines in visible brightness and persist for about 100 days after recovery to maximum brightness. Small residual winds of somewhat lower velocity are present outside of the decline and recovery periods. The correlations support models in which recently formed dust near the star is propelled outward at high speed by radiation pressure and drags the gas along with it.

Clayton, Geoffrey C.; Zhang Wanshu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Geballe, T. R., E-mail: gclayton@fenway.phys.lsu.edu, E-mail: wzhan21@lsu.edu, E-mail: tgeballe@gemini.edu [Gemini Observatory, 670 N. A'ohoku Place, Hilo, HI 96720 (United States)

2013-08-01

91

Selenium requirement of shrimp Penaeus chinensis  

NASA Astrophysics Data System (ADS)

Penaeus chinensis were reared in fibreglass tanks for the study of their selenium requirements. The shrimp were fed semipurified diets containing graded levels of selenium, and weight gains, activities of glutatione peroxidase (GSH-Px) and selenium contents in muscle and hepatopancreas were determined. Weight gain and GSH-Px activity were the highest when the shrimp were fed diet containing 20 mg/kg selenium. Good linear correlation was found between GSH-Px activities and selenium contents in the diets, and the number of healthy shrimp. The experiment showed that 20 mg/kg selenium in the diet is optimal for the shrimp and that GSH-Px activity can be an important biochemical index of the selenium nutrition status of the animal.

Tian, Yuchuan; Liu, Fayi

1993-09-01

92

The Brine Shrimp's Butterfly Stroke  

E-print Network

We investigate the fluid dynamics of brine shrimp larvae swimming in this gallery of fluid motion video. Time resolved particle image velocimetry was performed using nano-particles as seeding material to measure the time dependent velocity and vorticity fields. The Reynolds number of the flow was roughly 8 and the Womerseley number (ratio of periodic forcing to viscous forcing) was about 5. Vorticity dynamics reveals the formation of a vortex ring structure at the tip of each arm at the beginning of the power stroke. This two vortex system evolves dramatically with time as the stroke progresses. The outer circulation is noted to weaken while the inner circulation strengthens over the power stroke. The gaining strength of the inner vortex correlates with the acceleration and forward movement of the larvae.

Johnson, Brennan; Dasi, Lakshmi Prasad

2011-01-01

93

Inshore Environmental Effects on Brown Shrimp, Penaeus aztecus, and White Shrimp, P. setiferus,  

E-print Network

, and field observations of all stages including sexually mature adults. The quantity of sources cited length (TL = tip of rostrum to tip of telson), adults as animals which are sexually mature, and juveniles in population abundance of white shrimp may have accelerated the research on the brown shrimp, particularly

94

Incidence and inactivation of Listeria spp. on frozen shrimp  

Technology Transfer Automated Retrieval System (TEKTRAN)

Foodborne illness outbreaks occasionally occur as a result of microbiologically contaminated crustaceans, including shrimp. Foodborne pathogens occasionally found on shrimp include Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, and Vibrios. In this study the microbiological qualit...

95

Shrimp Farms and Mangroves, Gulf of Fonseca  

NASA Technical Reports Server (NTRS)

For decades, astronauts on space missions have documented land use changes around the world. In this pair of images, astronauts track the development of shrimp farming along the Honduran coastline of the Gulf of Fonseca between 1989 and 2001. Mariculture, primarily shrimp farming, has become a leading agricultural effort in Honduras. The regional transformation of large tracts of coastal swamps into shrimp farms blossomed throughout the 1990s. The top image was taken with color infrared film in 1989. Dense vegetation, like the coastal mangrove swamps and the forested slopes of Volcan Cosiguina show up as dark red. The bottom image, taken with color visible film by the crew of the most recent Space Shuttle mission in December 2001 shows that hundreds of square kilometers of coastal swamp, primarily in Honduras, have been converted to shrimp ponds. These appear as the light-colored, rectilinear land use pattern. The Honduras shrimp farms were hit hard by flooding after Hurricane Mitch in 1998, and a devastating virus in 1999-2000. It is not known how many of the ponds in this view are still functional. A vigorous debate continues about the sustainability of the shrimp farms and the impacts to the environment and coastal ecosystem due to mangrove clearing and mariculture waste production. Apart from the shrimp farms, the other prominent feature on these images is the impressive volcano Cosiguina, which erupted explosively in 1859 (the largest recorded eruption in the Western Hemisphere). Photograph STS-108-717-85 was taken in the December 2001 by the crew of Space Shuttle mission 108 using a Hasselblad camera with 250-mm lens. Photograph STS030-93-15 was taken in May 1989 using a Hasselblad camera and color infrared film. Both images are provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

2002-01-01

96

Pink shrimp as an indicator for restoration of everglades ecosystems  

Microsoft Academic Search

The pink shrimp, Farfantepenaeus duorarum, familiar to most Floridians as either food or bait shrimp, is ubiquitous in South Florida coastal and offshore waters and is proposed as an indicator for assessing restoration of South Florida's southern estuaries: Florida Bay, Biscayne Bay, and the mangrove estuaries of the lower southwest coast. Relationships between pink shrimp and salinity have been determined

Joan A. Browder; Michael B. Robblee

2009-01-01

97

Burrowing shrimp as foundation species in NE Pacific estuaries  

EPA Science Inventory

My talk will be about the my research to characterize the role that burrowing shrimp play as foundation/engineering species in Pacific NW estuaries. My research has focused on measuring the abundance & distribution of two species (ghost shrimp & mud shrimp) at ecosystem scales, ...

98

Tadpole shrimp structure macroinvertebrate communities in playa lake microcosms  

Microsoft Academic Search

Laboratory microcosms were used to assess whether tadpole shrimp, Triops sp., affect community structure of other native macroinvertebrates in playa lakes of the Southern High Plains of Texas. Removal of tadpole shrimp shortly after hatching reduced abundances of many taxa, and decreased subsequent taxonomic richness and diversity. For many invertebrates, the presence of tadpole shrimp in low numbers had a

Susan Harrell Yee; Michael R. Willig; Daryl L. Moorhead

2005-01-01

99

The hot R Coronae Borealis star DY Centauri is a binary  

E-print Network

The remarkable hot R Coronae Borealis star DY Cen is revealed to be the first and only binary system to be found among the R Coronae Borealis (RCB) stars and their likely relatives, including the Extreme Helium stars and the hydrogen-deficient carbon stars. Radial velocity determinations from 1982-2010 have shown DY Cen is a single-lined spectroscopic binary in an eccentric orbit with a period of 39.67 days. It is also one of the hottest and most H-rich member of the class of RCB stars. The system may have evolved from a common-envelope to its current form.

Rao, N Kameswara; Garcia-Hernandez, D A; Jeffery, C Simon; Woolf, Vincent M; McArthur, Barbara

2012-01-01

100

High-resolution spectroscopy of the R Coronae Borealis and Other Hydrogen Deficient Stars  

E-print Network

High-resolution spectroscopy is a very important tool for studying stellar physics, perhaps, particularly so for such enigmatic objects like the R Coronae Borealis and related Hydrogen deficient stars that produce carbon dust in addition to their peculiar abundances. Examples of how high-resolution spectroscopy is used in the study of these stars to address the two major puzzles are presented: (i) How are such rare H-deficient stars created? and (ii) How and where are the obscuring soot clouds produced around the R Coronae Borealis stars?

Rao, N Kameswara

2010-01-01

101

Aploparaksis borealis sp. n. (Cestoda: Hymenolepididae) from passeriform and charadriiform birds in Chukotka and Alaska.  

PubMed

Aploparaksis borealis sp. n. (Cestoda: Hymenolepididae), from the long-tailed jaeger, Stercorarisu longicaudus Vieillot, on the Seward Peninsula, Alaska, and from the red-throated pipit, Anthus cervinus (Pallas), and the Lapland longspur, Calcarius lapponicus (Linnaeus), in Chukotka, northestern Siberia, is described. This cestode is distinguished by the structure of the cirrus and other morphologic characters from other species of Aploparaksis Clerc 1903 in which there are 10 rostellar hooks and the vitelline gland is aporal to the ovary. A. borealis is the first species of Aploparaksis to be reported from birds representing 2 orders (Passeriformes and Charadriiformes). PMID:845746

Bondarenko, S K; Rausch, R L

1977-02-01

102

The Corona Borealis Supercluster - II: Mass Estimation & Simulations  

NASA Astrophysics Data System (ADS)

Recently, Pearson & Batuski (2013) found that there should be little chance of finding extended bound structure in the Corona Borealis supercluster (CSC) if most of the mass is contained within the clusters themselves. However, Batiste & Batuski (2013) found evidence for CSC being in a state of collapse through a Fundamental Plane (FP) analysis. The contradiction of the results suggests strongly that there is a substantial matter component outside of the clusters. Using methods developed by Small et al. 1998, Reisenegger et al. 2000, Dünner et al. 2007, as well as a method we developed ourselves based on the spherical collapse model, we find evidence for between 1.91 and 13.9×1016 h-1 M? in the CSC region. The lower end of this mass range would mean there is about twice as much mass outside of the clusters than within the clusters themselves, similar to the finding of Proust et al. 2006 for the Shapley supercluster (SSC). Assuming an inter-cluster matter component of 3.8 × 1016 h-1 M? (Small et al. 1998), and line-of-sight peculiar velocities implied by the FP at present, our simulations show that there is a ~70% chance of the entire supercluster being gravitationally bound.

Pearson, David; Batiste, M.; Batuski, D. J.

2014-01-01

103

A dynamical analysis of the Corona Borealis supercluster  

NASA Astrophysics Data System (ADS)

Using data from the Sloan Digital Sky Survey we assess the current dynamical state of the Corona Borealis supercluster (CSC), a highly dense and compact supercluster at z ? 0.07. The Fundamental Plane relation is used to determine redshift-independent distances to six clusters in the densest region of the supercluster, with mean accuracy in the relative distance estimates of 4 per cent. Peculiar velocities determined from these distance estimates indicate that the clusters have broken from the Hubble flow, suggesting that the CSC likely contains two regions that have reached turnaround and are currently undergoing gravitational collapse. These results provide the strongest observational evidence to date that the CSC is a bound system similar to the much more extensive Shapley supercluster, which is the most extensive confirmed bound supercluster yet identified in the Universe. When compared with simulations of the CSC our results require substantially more mass than is contained within the clusters, possibly indicating a significant intercluster dark matter component. In order to facilitate comparison with studies for which spectroscopic data are not available, an alternative analysis of the dynamics is made using the Kormendy relation as a distance indicator. The results are generally consistent with those of the Fundamental Plane and suggest similar global dynamics, but we find that the relatively sparse sampling of the clusters makes the Kormendy relation less reliable overall and more susceptible to small systematic differences between the cluster samples.

Batiste, Merida; Batuski, David J.

2013-12-01

104

Aurorae: The earliest datable observation of the aurora borealis  

NASA Astrophysics Data System (ADS)

The Late Babylonian astronomical texts, discovered at the site of Babylon (32.5°N, 44.4°E) more than a century ago, contain what is probably the earliest reliable account of the aurora borealis. A clay tablet recording numerous celestial observations made by the official astronomers during the 37th year of King Nebuchadnezzar II (568/567 BC) describes an unusual ``red glow'' in the sky at night; the exact date of this observation corresponds to the night of 12/13 March in 567 BC. The most likely interpretation of the phenomenon is an auroral display. This event occurred several centuries before the first clearly identifiable observation of the aurora from elsewhere in the world, namely China in 193 BC. The Babylonian auroral observation is remarkable in the sense that it is one of a series of carefully recorded astronomical observations, for each of which the year, month and day are known precisely. This observation occurred at a time when the geomagnetic (dipole) latitude of Babylon was about 41°N compared with the present value of 27.5°N, suggesting a higher auroral incidence at Babylon in 567 BC than at present.

Stephenson, F. Richard; Willis, David M.; Hallinan, Thomas J.

2004-12-01

105

NSV 11154 Is a New R Coronae Borealis Star  

NASA Astrophysics Data System (ADS)

NSV 11154 has been confirmed as a new member of the rare hydrogen-deficient R Coronae Borealis (RCB) stars based on new photometric and spectroscopic data. Using new photometry, as well as archival plates from the Harvard archive, we have constructed the historical light curve of NSV 11154 from 1896 to the present. The light curve shows the sudden, deep, irregularly spaced declines characteristic of RCB stars. The visible spectrum is typical of a cool (Teff ? 5000 K) RCB star, showing no hydrogen lines, strong C2 Swan bands, and no evidence of 13C. In addition, the star shows small pulsations that are typical of an RCB star and an infrared excess due to circumstellar dust, with a temperature of ˜800 K. The distance to NSV 11154 is estimated to be ˜14.5 kpc. RCB stars are very rare in the Galaxy, so each additional star is important to population studies leading to a better understanding the origins of these mysterious stars. Among the known sample of RCB stars, NSV 11154 is unusual in that it lies well above the Galactic plane (5 kpc) and away from the Galactic center, which suggests that its parent population is neither thick disk nor bulge.

Kijbunchoo, Nutsinee; Clayton, Geoffrey C.; Vieux, Timothy C.; Dickerman, N.; Hillwig, T. C.; Welch, D. L.; Pagnotta, Ashley; Tang, Sumin; Grindlay, J. E.; Henden, A.

2011-10-01

106

NSV 11154 Is a New R Coronae Borealis Star  

E-print Network

NSV 11154 has been confirmed as a new member of the rare hydrogen deficient R Coronae Borealis (RCB) stars based on new photometric and spectroscopic data. Using new photometry, as well as archival plates from the Harvard archive, we have constructed the historical lightcurve of NSV 11154 from 1896 to the present. The lightcurve shows the sudden, deep, irregularly spaced declines characteristic of RCB stars. The visible spectrum is typical of a cool (Teff < 5000 K) RCB star showing no hydrogen lines, strong C2 Swan bands, and no evidence of 13C. In addition, the star shows small pulsations typical of an RCB star, and an infrared excess due to circumstellar dust with a temperature of ~800 K. The distance to NSV 11154 is estimated to be ~14.5 kpc. RCB stars are very rare in the Galaxy so each additional star is important to population studies leading to a better understanding the origins of these mysterious stars. Among the known sample of RCB stars, NSV 11154 is unusual in that it lies well above the Galact...

Kijbunchoo, Nutsinee; Vieux, Timothy C; Dickerman, N; Hillwig, T C; Welch, D L; Pagnotta, Ashley; Tang, Sumin; Grindlay, J E; Henden, A

2011-01-01

107

V532 Oph is a New R Coronae Borealis Star  

E-print Network

V532 Oph has been found to be a member of the rare, hydrogen-deficient R Coronae Borealis (RCB) stars from new photometric and spectroscopic data reported in this paper. The lightcurve of V532 Oph shows the sudden, deep, irregularly spaced declines characteristic of RCB stars. Its optical spectrum is typical of a warm (T(eff)~7000 K) RCB star, showing weak or absent hydrogen lines, the C2 Swan bands, and no evidence for 13C. In addition, the star shows small pulsations typical of an RCB star and an infrared excess due to circum- stellar dust. It also appears to be significantly reddened by foreground dust. The distance to V532 Oph is estimated to be 5.5-8.7 kpc. These new data show that this star was misclassified as an eclipsing binary in the General Catalog of Variable Stars. The new data presented here for V532 Oph reveal the power of high-quality, high-cadence all-sky photometric surveys, such as ASAS-3, to identify new RCB candidates on the basis of lightcurve data alone, now that they have been collecti...

Clayton, Geoffrey C; Wils, P; Welch, D L

2009-01-01

108

Will R Coronae Borealis Ever Return to Maximum Light?  

NASA Astrophysics Data System (ADS)

R Coronae Borealis (R CrB) has been in a deep decline for almost 7 years. Before that, it spent 6 uninterrupted years at maximum light. R CrB is the prototype of its eponymous class of stars, which are very rare, and have many unusual characteristics including extreme hydrogen deficiency, and large, sudden declines in brightness of 8 magnitudes or more. These declines are caused by clouds of carbon dust forming near the atmospheres of the stars, which are later dissipated by radiation pressure. The RCB stars are true irregular variables in that the timing of their declines cannot be predicted, but several RCB stars are also known to begin their declines at a particular phase of their pulsations. There is a wide range of dust formation activity among these stars, as well as as a wide variation in the level of activity for an individual star over time. Long Time Domain observations of the RCB stars are necessary to understand the frequency of their declines, and to give clues about how and when the dust forms around these enigmatic stars.

Clayton, Geoffrey C.

2014-06-01

109

Oxygen isotopic ratios in cool R Coronae Borealis stars  

E-print Network

We investigate the relationship between R Coronae Borealis (RCB) stars and hydrogen-deficient carbon (HdC) stars by measuring precise 16O/18O ratios for five cool RCB stars. The 16O/18O ratios are derived by spectrum synthesis from high-resolution (R=50,000) K-band spectra. Lower limits to the 16O/17O and 14N/15}N ratios as well as Na and S abundances (when possible) are also given. RCB stars in our sample generally display less 18O than HdC stars - the derived 16O/18O ratios range from 3 to 20. The only exception is the RCB star WX CrA, which seems to be a HdC-like star with 16O/18O=0.3. Our result of a higher 16O/18O ratio for the RCB stars must be accounted for by a theory of the formation and evolution of HdC and RCB stars. We speculate that a late dredge-up of products of He-burning, principally 12C and 16O, may convert a 18O-rich HdC star into a 18O-poor RCB star as the H-deficient star begins its final evolution from a cool supergiant to the top of the white dwarf cooling track.

Garcia-Hernandez, D Anibal; Rao, N Kameswara; Hinkle, Ken H; Eriksson, Kjell

2010-01-01

110

Pathogenicity of Bacillus thuringiensis for penaeid shrimp  

E-print Network

is insupportable due to the similarity of the cells in the control guts. The pH's of penaeid shrimp digestive tracts have not been determined by previous investigators. The ingestion 38 of indicators present in the pelletized ration appears to be an effective... of the shrimp which had been fed the BT. Histologic examination revealed BT within the lumen of the gut, but deterioration of the gut integrity could not be attributed to the bac- teria. The addition of 1. 3% borax to the pelletized ration did not enhance...

Lehrer, Janis Ellen

2012-06-07

111

Habitat Suitability Index Models: Northern Gulf of Mexico Brown Shrimp and White Shrimp  

USGS Publications Warehouse

A review and synthesis of existing information were used to develop estuarine habitat models for brown shrimp (Penaeus aztecus) and white shrimp (Penaeus setiferus). The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for estuarine areas of the northern Gulf of Mexico. Habitat suitability indexes are designed for use with the habitat evaluation procedures developed by the U.S. Fish and Wildlife Service.

Turner, Robert Eugene; Brody, Michael S.

1983-01-01

112

76 FR 23972 - Certain Frozen Warmwater Shrimp From Brazil, India, the People's Republic of China, Thailand, and...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From Brazil, India, the People's Republic of China...frozen warmwater shrimp (shrimp) from Brazil, India, the People's Republic of China...antidumping duty orders on shrimp from Brazil, India, the PRC, Thailand, and...

2011-04-29

113

MFR PAPER 1171 Shrimp taste and vitamin  

E-print Network

MFR PAPER 1171 Shrimp taste and vitamin content did not differ markedly in thermal and microwave been done on vitamin anal '>es of \\egetables cooked b) micro~\\ ave and ~onven ti )nalmean hot spot. by employing peliodic stilTing. Vitamin selected for thi "tud) \\~e;e those \\\\ hich had been

114

Smart shrimp hatchery using Mikros platform  

Microsoft Academic Search

In this paper, wireless sensor networks (WSNs) have been deployed to monitor the temperature and control the air conditions in a shrimp hatchery. The in-house nodes called Mikros are currently employed in the clustered WSNs. XBee platform is also included to the system as a cluster head and repeater. All data and control live onto the web application and iPhone

S. Charoenpanyasak; W. Suntiamorntut; T. Phatthanatraiwat; J. Ruksachum

2011-01-01

115

COBALT-60 Gamma Irradiation of Shrimp.  

NASA Astrophysics Data System (ADS)

Meta- and ortho-tyrosine were measured using high performance liquid chromatography (HPLC) in conjunction with electrochemical detection in shrimp irradiated using cobalt-60 gamma radiation in the absorbed dose range 0.8 to 6.0 kGy, in nonirradiated shrimp, and in bovine serum albumin (BSA) irradiated in dilute aqueous solution at 25.0 kGy. Ortho-tyrosine was measured in nonirradiated BSA. Para-, meta-, and ortho-tyrosine were measured using HPLC in conjunction with uv-absorption detection in dilute aqueous solutions of phenylalanine irradiated in the absorbed dose range 16.0 to 195.0 kGy. The measured yields of tyrosine isomers were approximately linear as a function of absorbed dose in shrimp, and in irradiated solutions of phenylalanine up to 37.0 kGy. The occurrence of meta- and ortho-tyrosine, which had formerly been considered unique radiolytic products, has not previously been reported in nonirradiated shrimp or BSA. The conventional hydrolyzation and analytical techniques used in the present study to measure meta- and ortho-tyrosine may provide the basis for a method to detect and determine the dose used in food irradiation.

Sullivan, Nancy L. B.

116

Cobalt-60 gamma irradiation of shrimp  

SciTech Connect

Meta- and ortho-tyrosine were measured using high performance liquid chromatography (HPLC) in conjunction with electrochemical detection in shrimp irradiated using cobalt-60 gamma radiation in the absorbed dose range 0.8 to 6.0 kGy, in nonirradiated shrimp, and in bovine serum albumin (BSA) irradiated in dilute aqueous solution at 25.0 kGy. Ortho-tyrosine was measured in nonirradiated BSA. Para-, meta-, and ortho-tyrosine was measured using HPLC in conjunction with uv-absorption detection in dilute aqueous solutions of phenylalanine irradiated in the absorbed dose range 16.0 to 195.0 kGy. The measured yields of tyrosine isomers were approximately linear as a function of absorbed dose in shrimp, and in irradiated solutions of phenylalanine up to 37.0 kGy. The occurrence of meta- and ortho-tyrosine, which had formerly been considered unique radiolytic products, has not previously been reported in nonirradiated shrimp or BSA. The conventional hydrolyzation and analytical techniques used in the present study to measure meta- and ortho-tyrosine may provide the basis for a method to detect and determine the dose used in food irradiation.

Sullivan, N.L.B.

1993-01-01

117

GLUCOSE OXIDASE REDUCES OXIDATION IN FROZEN SHRIMP  

E-print Network

role oxygen can have during storage of foods (Scott, 1958). Glucose oxidase-catalase preparations are used to carry out the net reaction: 2 glucose + oxygen glucose oxidase > 2 gluconic acid. catalase of glucose oxidase -catalase would probably be more obvious in shrimp, which were packed in transparent bags

118

Pacific white shrimp culture in inland ponds  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Pacific white shrimp (Litopenaeus vannamei), a tropical species grown throughout Latin America and now introduced into Asia, adapts to and grows well in low-salinity water. Pond culture of L. vannamei has expanded to inland regions across the southern US where low-salinity ground water is availa...

119

CO? efflux from shrimp ponds in Indonesia.  

PubMed

The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored 'blue' carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO?) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO? efflux from the floors and walls of shrimp ponds. Rates of CO? efflux within shrimp ponds were 4.37 kg CO? m?² y?¹ from the walls and 1.60 kg CO? m?² y?¹ from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO? emissions to the atmosphere between 5.76 and 13.95 Tg y?¹. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO? emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO? released to atmosphere. PMID:23755306

Sidik, Frida; Lovelock, Catherine E

2013-01-01

120

Archaeorhizomyces borealis sp. nov. and a sequence-based classification of related soil fungal species.  

PubMed

The class Archaeorhizomycetes (Taphrinomycotina, Ascomycota) was introduced to accommodate an ancient lineage of soil-inhabiting fungi found in association with plant roots. Based on environmental sequencing data Archaeorhizomycetes may comprise a significant proportion of the total fungal community in soils. Yet the only species described and cultivated in this class is Archaeorhizomyces finlayi. In this paper, we describe a second species from a pure culture, Archaeorhizomyces borealis NS99-600(T) (=CBS138755(ExT)) based on morphological, physiological, and multi-locus molecular characterization. Archaeorhizomyces borealis was isolated from a root tip of a Pinus sylvestris seedling grown in a forest nursery in Lithuania. Analysis of Archaeorhizomycete species from environmental samples shows that it has a Eurasian distribution and is the most commonly observed species. Archaeorhizomyces borealis shows slow growth in culture and forms yellowish creamy colonies, characteristics that distinguish A. borealis from its closest relative A. finlayi. Here we also propose a sequence-based taxonomic classification of Archaeorhizomycetes and predict that approximately 500 species in this class remain to be isolated and described. PMID:25457942

Menkis, Audrius; Urbina, Hector; James, Timothy Y; Rosling, Anna

2014-12-01

121

Prelaying exodus of Cory's Shearwaters ( Calonectris diomedea borealis ) on Selvagem Grande  

Microsoft Academic Search

Summary We stayed on the Portugese island of Selvagem Grande, 30° N 16° W, 300 km south of Madeira and 200 km north of Tenerife, from 9 May to 3 June 1991 in order to study the prelaying exodus in Cory's Shearwaters (Calonectris diomedea borealis) and its connection with the colony attendance cycles described earlier. Laying took place on 1.5

Christian Jouanin; Francis Roux; Jean-Louis Mougin I; Jean-Claude Stahl

2001-01-01

122

The Norris Survey of the Corona Borealis Supercluster. II. Galaxy Evolution with Redshift and Environment  

Microsoft Academic Search

We measure the field galaxy luminosity function (LF) as a function of color and redshift from z = 0 to z = 0.5 using galaxies from the Norris Survey of the Corona Borealis Supercluster. The data set consists of 603 field galaxies with 0 < z <= 0.5 and spans a wide range in apparent magnitude (14.0 <~ r <~

Todd A. Small; Wallace L. W. Sargent; Donald Hamilton

1997-01-01

123

The MACHO Project LMC Variable Star Inventory. X. The R Coronae Borealis Stars  

Microsoft Academic Search

We report the discovery of eight new R Coronae Borealis (RCB) stars in the Large Magellanic Cloud (LMC) using the MACHO project photometry database. The discovery of these new stars increases the number of known RCB stars in the LMC to thirteen. We have also discovered four stars similar to the Galactic variable DY Per. These stars decline much more

C. Alcock; R. A. Allsman; D. R. Alves; T. S. Axelrod; A. Becker; D. P. Bennett; Geoffrey C. Clayton; K. H. Cook; N. Dalal; A. J. Drake; K. C. Freeman; M. Geha; K. D. Gordon; K. Griest; D. Kilkenny; S. L. Marshall; D. Minniti; K. A. Misselt; C. A. Nelson; B. A. Peterson; P. Popowski; M. R. Pratt; P. J. Quinn; C. W. Stubbs; W. Sutherland; A. Tomaney; T. Vandehei; D. L. Welch

2001-01-01

124

Discovery of Five New R. Coronae Borealis Stars in the MACHO Galactic Bulge Database  

Microsoft Academic Search

We have identified five new R Coronae Borealis (RCB) stars in the Galactic bulge using the MACHO Project photometry database, raising the total number of known Galactic RCB stars to about 40. We have obtained spectra to confirm the identifications. The fact that four out of the five newly identified RCB stars are ''cool'' (T{sub eff} < 6000 K) rather

A. Zaniewski; Geoffrey C. Clayton; D. L. Welch; Karl D. Gordon; D. Minniti; K. H. Cook

2005-01-01

125

The MACHO Project Large Magellanic Cloud Variable Star Inventory. IV. New R Coronae Borealis Stars  

Microsoft Academic Search

We report the discovery of two new R Coronae Borealis (RCB) stars in the LMC using the MACHO project photometry database. The identification of both stars has been confirmed spectroscopically. One is a cool RCB star (T_eff_ ~ 5000 K), characterized by very strong Swan bands of C_2_ and violet bands of CN, and weak or absent Balmer lines, G

C. Alcock; R. A. Allsman; D. R. Alves; T. S. Axelrod; A. Becker; D. P. Bennett; G. C. Clayton; K. H. Cook; K. C. Freeman; K. Griest; J. A. Guern; D. Kilkenny; M. J. Lehner; S. L. Marshall; D. Minniti; M. R. Pratt; P. J. Quinn; A. W. Rodgers; C. W. Stubbs; W. Sutherland; D. L. Welch

1996-01-01

126

Millimeter Observation of the SZ Effect in the Corona Borealis Supercluster  

Microsoft Academic Search

We have observed the Corona Borealis supercluster with the Millimeter and Infrared Testa Grigia Observatory (MITO), located in the Italian Alps, at 143, 214, 272, and 353 GHz. We present a description of the measurements, data analysis, and results of the observations together with a comparison with observations performed at 33 GHz with the Very Small Array (VSA) interferometer situated

E. S. Battistelli; M. De Petris; L. Lamagna; R. A. Watson; R. Rebolo; F. Melchiorri; R. Génova-Santos; G. Luzzi; S. De Gregori; J. A. Rubiño-Martin; R. D. Davies; R. J. Davis; K. Grainge; M. P. Hobson; R. D. E. Saunders; P. F. Scott

2006-01-01

127

Interpretation of the spectral and photometric variations of R Coronae Borealis  

Microsoft Academic Search

A consistent picture explaining both the spectral and photometric (infrared and visual) variations of R Coronae Borealis is developed. It is found that the extreme infrared maximum and minimum can be fitted by dispersion of the same mass of graphite dust. Random clumps of this dust crossing the line of sight both obscure the visual continuum of the object and

L. Hartmann; J. P. Apruzese

1976-01-01

128

The Norris Survey of the Corona Borealis Supercluster. I. Observations and Catalog Construction  

Microsoft Academic Search

We have conducted a redshift survey of a 6 deg x 6 deg region in the core of the Corona Borealis Supercluster using the 176 fiber Norris Spectrograph on the Hale 5 m telescope. The input catalog from which we selected objects is based on machine scans of Schmidt plates and consists of over 5 x 105 objects. As it

Todd A. Small; Wallace L. W. Sargent; Donald Hamilton

1997-01-01

129

What are the Hot R Coronae Borealis Stars?  

E-print Network

We investigate the evolutionary status of four stars: V348 Sgr, DY Cen and MV Sgr in the Galaxy and HV 2671 in the LMC. These stars have in common random deep declines in visual brightness which are characteristic for R Coronae Borealis (RCB) stars. RCB stars are typically cool, hydrogen deficient supergiants. The four stars studied in this paper are hotter (T$_{\\rm eff}$ = 15-20 kK) than the majority of RCB stars (T$_{\\rm eff}$ = 5000-7000 K). Although these are commonly grouped together as the \\emph{hot RCB stars} they do not necessarily share a common evolutionary history. We present new observational data and an extensive collection of archival and previously-published data which is reassessed to ensure internal consistency. We find temporal variations of various properties on different time scales which will eventually help us to uncover the evolutionary history of these objects. DY Cen and MV Sgr have typical RCB helium abundances which excludes any currently known post-AGB evolutionary models. Moreover, their carbon and nitrogen abundances present us with further problems for their interpretation. V348 Sgr and HV 2671 are in general agreement with a born-again post-AGB evolution and their abundances are similar to Wolf-Rayet central stars of PN. The three Galactic stars in the sample have circumstellar nebulae which produce forbidden line radiation (for HV 2671 we have no information). V348 Sgr and DY Cen have low density, low expansion velocity nebulae (resolved in the case of V348 Sgr), while MV Sgr has a higher density, higher expansion velocity nebula.

Orsola De Marco; Geoffrey C. Clayton; F. Herwig; D. L. Pollacco; J. S. Clark; David Kilkenny

2002-03-08

130

78 FR 42492 - Certain Frozen Warmwater Shrimp From India: Final Results of Antidumping Duty Administrative...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From India: Final Results of Antidumping Duty Administrative...on certain frozen warmwater shrimp from India.\\1\\ The period of review (POR) is...See Certain Frozen Warmwater Shrimp From India; Preliminary Results of Antidumping...

2013-07-16

131

50 CFR 622.201 - South Atlantic rock shrimp limited access.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false South Atlantic rock shrimp limited access. 622.201 Section...Atlantic Region § 622.201 South Atlantic rock shrimp limited access. (a) Commercial Vessel Permits for Rock Shrimp (South Atlantic EEZ)....

2013-10-01

132

76 FR 18157 - Certain Frozen Warmwater Shrimp From Brazil, India, and Thailand: Notice of Initiation of...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From Brazil, India, and Thailand: Notice of Initiation...frozen warmwater shrimp (shrimp) from Brazil, India and Thailand. The anniversary...Kate Johnson at (202) 482-4929 (Brazil), Henry Almond at (202)...

2011-04-01

133

75 FR 48724 - Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam  

Federal Register 2010, 2011, 2012, 2013

...Review)] Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and...

2010-08-11

134

75 FR 57501 - Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam  

Federal Register 2010, 2011, 2012, 2013

...Review)] Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and...

2010-09-21

135

75 FR 22370 - Certain Frozen Warmwater Shrimp From Brazil, Ecuador, India, the People's Republic of China...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From Brazil, Ecuador, India, the People's Republic...of certain frozen warmwater shrimp from Brazil, Ecuador, India, the People's Republic...Frozen and Canned Warmwater Shrimp From Brazil, 69 FR 76910 (December 23,...

2010-04-28

136

75 FR 1078 - Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam  

Federal Register 2010, 2011, 2012, 2013

...Review)] Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and...

2010-01-08

137

75 FR 17693 - Certain Frozen Warmwater Shrimp from Brazil, India, and Thailand: Notice of Initiation of...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp from Brazil, India, and Thailand: Notice of Initiation...frozen warmwater shrimp (shrimp) from Brazil, India and Thailand. The anniversary...Rebecca Trainor at (202) 482-4007 (Brazil), Elizabeth Eastwood at (202)...

2010-04-07

138

75 FR 22424 - Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam  

Federal Register 2010, 2011, 2012, 2013

...Review)] Frozen Warmwater Shrimp From Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and Vietnam...orders on frozen warmwater shrimp from Brazil, China, India, Thailand, and...

2010-04-28

139

The Norris Survey of the Corona Borealis Supercluster: III. Structure and Mass of the Supercluster  

E-print Network

(Abridged) We present a study of the structure and dynamics of the Corona Borealis Supercluster (z ~ 0.07) based on the redshifts for 528 galaxies in the supercluster. The galaxy distribution within Corona Borealis is clumpy and appears overall to be far from relaxed. A background supercluster at z ~ 0.11 makes a substantial contribution to the projected surface density of galaxies in the Corona Borealis field. In order to estimate the mass of the supercluster, we have assumed that the mass of the supercluster is proportional to v^2r, where v and r are suitable scale velocity and radius, respectively, and we have used N-body simulations of both critical- and low-density universes to determine the applicability of standard mass estimators based on this assumption. Although superclusters are obviously not in equilibrium, our simulations demonstrate that the virial mass estimator yields mass estimates with an insignificant bias and a dispersion of only ~25% for objects with overdensities >~ 5. Non-uniform spatial sampling can, however, cause systematic underestimates by as much as 30%. All of our simulated superclusters turn out to be bound, and based on the overdensity of the Corona Borealis supercluster, we believe it is also very likely to be bound and may well have started to collapse. The mass of Corona Borealis is at least 3 x 10^16 solar masses, which yields a B(AB)-band mass-to-light ratio of 564h (M/L)_solar on scales of ~20 h^-1 Mpc. The background supercluster has a mass-to-light ratio of 726h (M/L)_solar. By comparing the supercluster mass-to-light ratios with the critical mass-to-light ratio required to close the universe, we determine that Omega_0 >~ 0.4 on supercluster scales.

Todd A. Small; Chung-Pei Ma; Wallace L. W. Sargent; Donald Hamilton

1997-08-16

140

Fin Whale (Balaenoptera physalus): Western North Atlantic Stock _____________________ 2 Sei Whale (Balaenoptera borealis): Nova Scotia Stock _______________________________ 9  

E-print Network

of seasonal occurrence and annual return that in some respects were similar to those shown for humpback whales1 Fin Whale (Balaenoptera physalus): Western North Atlantic Stock _____________________ 2 Sei Whale (Balaenoptera borealis): Nova Scotia Stock _______________________________ 9 Minke Whale (Balaenoptera

141

Development of the brine shrimp Artemia is accelerated during spaceflight  

NASA Technical Reports Server (NTRS)

Developmentally arrested brine shrimp cysts have been reactivated during orbital spaceflight on two different Space Shuttle missions (STS-50 and STS-54), and their subsequent development has been compared with that of simultaneously reactivated ground controls. Flight and control brine shrimp do not significantly differ with respect to hatching rates or larval morphology at the scanning and transmission EM levels. A small percentage of the flight larvae had defective nauplier eye development, but the observation was not statistically significant. However, in three different experiments on two different flights, involving a total of 232 larvae that developed in space, a highly significant difference in degree of flight to control development was found. By as early as 2.25 days after reactivation of development, spaceflight brine shrimp were accelerated, by a full instar, over ground control brine shrimp. Although developing more rapidly, flight shrimp grew as long as control shrimp at each developmental instar or stage.

Spooner, B. S.; Metcalf, J.; DeBell, L.; Paulsen, A.; Noren, W.; Guikema, J. A.

1994-01-01

142

Marine shrimp aquaculture and natural resource degradation in Thailand  

Microsoft Academic Search

Rising demand for shrimp in the developed nations has helped to foster a dramatic growth in marine shrimp aquaculture, particularly\\u000a in South America and South Asia. In Thailand, Marine shrimp aquaculture is now an important earmer of foreign exchange. The\\u000a growth in Production has been achieved through the expansion of the culture area and the adoption of intensive production\\u000a methods.

Mark Flaherty; Choomjet Karnjanakesorn

1995-01-01

143

Closed recirculating system for shrimp-mollusk polyculture  

Microsoft Academic Search

This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The\\u000a culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle,\\u000a water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation.\\u000a Constricted tagelus,Sinonovacula constricta, was selected

Xiongfei Wu; Zhidong Zhao; Deshang Li; Kangmei Chang; Zhuanshang Tong; Liegang Si; Kaichong Xu; Bailin Ge

2005-01-01

144

A bio-economic model for penaeid shrimp mariculture systems  

E-print Network

Pound (Base Value: $0. 15) Ex-Ves el Price Per Pound of Tails (Base Value: $g. 25) Sensitivity Summary VI SUKV&RY, LINITATIONS AND CONCLUSIONS REFERENCES 98 99 100 103 109 123 127 130 1)0 1/0 1/2 lgl 132 13lp 135 186 14. 2 VITA ix... varied for operations of 100, 500, and. 1000 acres, The table shrimp production system assumed. only one crop of 36 count (number per pound) shrimp. The bait shrimp production system assumed four crops of bait shrimp. Results from the analysis...

Adams, Charles M

1978-01-01

145

The R Coronae Borealis stars - atmospheres and abundances  

NASA Astrophysics Data System (ADS)

An abundance analysis of the H-deficient and He- and C-rich R Coronae Borealis (R CrB) stars has been undertaken to examine the ancestry of the stars. The investigation is based on high-resolution spectra and line-blanketed H-deficient model atmospheres. The models successfully reproduce the flux distributions and all spectral features, both molecular bands and high-excitation transitions, with one important exception, the C i lines. Since photoionization of C i dominates the continuous opacity, the line strengths of C i are essentially independent of the adopted carbon abundance and stellar parameters. All predicted C i lines are, however, much too strong compared with observations, with a discrepancy in abundance corresponding to 0.6 dex with little star-to-star scatter. Various solutions of this ``carbon problem'' have been investigated. A possible solution is that classical model atmospheres are far from adequate descriptions of supergiants such as the R CrB stars. We can also not exclude completely, however, the possibility that the gf-values for the C i lines are in error. This is supported by the fact that the C ii, [C i] and C_2 lines are reproduced by the models with no apparent complications. In spite of the carbon problem, various tests suggest that abundance ratios are little affected by the uncertainties. Judging by chemical composition, the R CrB stars can be divided into a homogeneous majority group and a diverse minority, which is characterized by extreme abundance ratios, in particular as regards Si/Fe and S/Fe. All stars show evidence of H- and He-burning in different episodes as well as mild s-process enhancements. Four of the majority members are Li-rich, while overabundances of Na, Al, Si and S are attributes of all stars. An anti-correlation found between the H and Fe abundances of H-deficient stars remains unexplained. These enigmatic stars are believed to be born-again giants, formed either through a final He-shell flash in a post-AGB star or through a merger of two white dwarfs. Owing to a lack of theoretical predictions of the resulting chemical compositions, identification of the majority and minority groups with the two scenarios is unfortunately only preliminary. Furthermore, Sakurai's object and V854 Cen exhibit aspects of both majority and minority groups, which may suggest that the division into two groups is too simplistic.

Asplund, M.; Gustafsson, B.; Lambert, D. L.; Rao, N. K.

2000-01-01

146

The Planet Orbiting r Coronae Borealis Robert W. Noyes 1 , Adam R. Contos 1 Sylvain G. Korzennik 1 Peter Nisenson 1 Timothy M. Brown 2 and Scott D. Horner 3  

E-print Network

The Planet Orbiting r Coronae Borealis Robert W. Noyes 1 , Adam R. Contos 1 Sylvain G. Korzennik 1 observationsof ae Coronae Borealis have allowed the determination of updated parameters of the 40­day orbit

147

Vortex Formation with a Snapping Shrimp Claw  

PubMed Central

Snapping shrimp use one oversized claw to generate a cavitating high speed water jet for hunting, defence and communication. This work is an experimental investigation about the jet generation. Snapping shrimp (Alpheus-bellulus) were investigated by using an enlarged transparent model reproducing the closure of the snapper claw. Flow inside the model was studied using both High-Speed Particle Image Velocimetry (HS-PIV) and flow visualization. During claw closure a channel-like cavity was formed between the plunger and the socket featuring a nozzle-type contour at the orifice. Closing the mechanism led to the formation of a leading vortex ring with a dimensionless formation number of approximate ?T*?4. This indicates that the claw might work at maximum efficiency, i.e. maximum vortex strength was achieved by a minimum of fluid volume ejected. The subsequent vortex cavitation with the formation of an axial reentrant jet is a reasonable explanation for the large penetration depth of the water jet. That snapping shrimp can reach with their claw-induced flow. Within such a cavitation process, an axial reentrant jet is generated in the hollow cylindrical core of the cavitated vortex that pushes the front further downstream and whose length can exceed the initial jet penetration depth by several times. PMID:24244273

Hess, David; Brücker, Christoph; Hegner, Franziska; Balmert, Alexander; Bleckmann, Horst

2013-01-01

148

Vortex formation with a snapping shrimp claw.  

PubMed

Snapping shrimp use one oversized claw to generate a cavitating high speed water jet for hunting, defence and communication. This work is an experimental investigation about the jet generation. Snapping shrimp (Alpheus-bellulus) were investigated by using an enlarged transparent model reproducing the closure of the snapper claw. Flow inside the model was studied using both High-Speed Particle Image Velocimetry (HS-PIV) and flow visualization. During claw closure a channel-like cavity was formed between the plunger and the socket featuring a nozzle-type contour at the orifice. Closing the mechanism led to the formation of a leading vortex ring with a dimensionless formation number of approximate ?T*?4. This indicates that the claw might work at maximum efficiency, i.e. maximum vortex strength was achieved by a minimum of fluid volume ejected. The subsequent vortex cavitation with the formation of an axial reentrant jet is a reasonable explanation for the large penetration depth of the water jet. That snapping shrimp can reach with their claw-induced flow. Within such a cavitation process, an axial reentrant jet is generated in the hollow cylindrical core of the cavitated vortex that pushes the front further downstream and whose length can exceed the initial jet penetration depth by several times. PMID:24244273

Hess, David; Brücker, Christoph; Hegner, Franziska; Balmert, Alexander; Bleckmann, Horst

2013-01-01

149

Closed recirculating system for shrimp-mollusk polyculture  

NASA Astrophysics Data System (ADS)

This paper deals with a new system of aquaculture, i.e., a closed recirculating system for shrimp-mollusk polyculture. The culture system consisted of several shrimp ponds, a mollusk water-purifying pond and a reservoir. During the production cycle, water circulated between the shrimp and mollusk ponds, and the reservoir compensated for water loss from seepage and evaporation. Constricted tagelus, Sinonovacula constricta, was selected as the cultured mollusk, and Pacific white shrimp, Litopenaeus vannamei, as the cultured shrimp. The main managing measures during the production cycle were: setting and using the aerators; introducting the probiotic products timely into the shrimp ponds; adopting a “pen-closing” method for controlling shrimp viral epidemics; setting the flow diversion barriers in the mollusk pond to keep the circulating water flowing through the pond along a sine-like curve and serve as substrate for biofilm; no direct feeding was necessary for the cultured mollusk until the co-cultured shrimp was harvested; natural foods in the water from the shrimp ponds was used for their foods. Two sets of the system were used in the experiment in 2002 and satisfactory results were achieved. The average yield of the shrimp was 11 943.5 kg/hm2, and that of the mollusk was 16 965 kg/hm2. After converting the mollusk yield into shrimp yield at their market price ratio, the food coefficient of the entire system averaged at as low as 0.81. The water quality in the ponds was maintained at a desirable level and no viral epidemics were discovered during the production cycle.

Wu, Xiongfei; Zhao, Zhidong; Li, Deshang; Chang, Kangmei; Tong, Zhuanshang; Si, Liegang; Xu, Kaichong; Ge, Bailin

2005-12-01

150

Biology, genome organization, and evolution of parvoviruses in marine shrimp.  

PubMed

As shrimp aquaculture has evolved from a subsistent farming activity to an economically important global industry, viral diseases have also become a serious threat to the sustainable growth and productivity of this industry. Parvoviruses represent an economically important group of viruses that has greatly affected shrimp aquaculture. In the early 1980s, an outbreak of a shrimp parvovirus, infectious hypodermal and hematopoietic necrosis virus (IHHNV), led to the collapse of penaeid shrimp farming in the Americas. Since then, considerable progress has been made in characterizing the parvoviruses of shrimp and developing diagnostic methods aimed to preventing the spread of diseases caused by these viruses. To date, four parvoviruses are known that infect shrimp; these include IHHNV, hepatopancreatic parvovirus (HPV), spawner-isolated mortality virus (SMV), and lymphoid organ parvo-like virus. Due to the economic repercussions that IHHNV and HPV outbreaks have caused to shrimp farming over the years, studies have been focused mostly on these two pathogens, while information on SMV and LPV remains limited. IHHNV was the first shrimp virus to be sequenced and the first for which highly sensitive diagnostic methods were developed. IHHNV-resistant lines of shrimp were also developed to mitigate the losses caused by this virus. While the losses due to IHHNV have been largely contained in recent years, reports of HPV-induced mortalities in larval stages in hatchery and losses due to reduced growth have increased. This review presents a comprehensive account of the history and current knowledge on the biology, diagnostics methods, genomic features, mechanisms of evolution, and management strategies of shrimp parvoviruses. We also highlighted areas where research efforts should be focused in order to gain further insight on the mechanisms of parvoviral pathogenicity in shrimp that will help to prevent future losses caused by these viruses. PMID:24751195

Dhar, Arun K; Robles-Sikisaka, Refugio; Saksmerprome, Vanvimon; Lakshman, Dilip K

2014-01-01

151

Sensory differentiation of shrimp using a trained descriptive analysis panel  

Microsoft Academic Search

A trained descriptive analysis panel evaluated raw and cooked sensory attributes for both fresh and frozen commercially available shrimp. While significant differences in sensory attributes existed among the type of frozen shrimp evaluated (Georgia white, Georgia brown, Gulf white, Gulf brown, Gulf pink, Honduras white, Belise white, Columbia white, and Burma black tiger), only appearance attributes could uniquely differentiate a

M. C. Erickson; M. A. Bulgarelli; A. V. A. Resurreccion; R. A. Vendetti; K. A. Gates

2007-01-01

152

CUTICULAR LESIONS INDUCED IN GRASS SHRIMP EXPOSED TO HEXAVALENT CHROMIUM  

EPA Science Inventory

Adult grass shrimp were exposed to four concentrations (0.5, 1.0, 2.0 and 4.0 ppm) of hexavalent chromium for 38 days. At the end of the exposure period, over 50% of the surviving shrimp possessed cuticular lesions that had many of the gross characteristics of 'shell disease.' Th...

153

STAGE I ZOEAE OF A CRANGONID SHRIMP, CRANGON FRANCISCORUM ANGUSTIMANA,  

E-print Network

NOTES STAGE I ZOEAE OF A CRANGONID SHRIMP, CRANGON FRANCISCORUM ANGUSTIMANA, HATCHED FROM OVIGEROUS FEMALES COLLECTED IN KACHEMAK BAY, ALASKA Information on the larval stages of crangonid shrimp ofthe North Pacific Ocean is meager. Need- ler (1941) described the first zoeal stage of Cran- gon septemspinosa (as

154

SIZE DISTRIBUTION OF PINK SHRIMP, Penaeus duorarum, AND FLEET  

E-print Network

and depth 10 Fleet concentrations 16 Shrimp discarding 16 Summary 22 Literature cited 23 Appendix 24 FIGURES 1. Map of south Florida showing the Tortugas fishing grounds 2 2. Important features of Tortugas 10 7. Relationship of depth of water and average size of female shrimp 10 8. Relationship of depth

155

LENGTH-WEIGHT RELATION IN THE COMMON OR WHITE SHRIMP  

E-print Network

-year period in Texas. Material was obtained during each month of the year. Measurements of total lengthLENGTH-WEIGHT RELATION IN THE COMMON OR WHITE SHRIMP PENAEUS SETIFERUS Marine Biological, Arnie J. Suomela, Commissioner LENGTH-WEIGHT RELATION IN THE COMMON OR WHITE SHRIMP, PENAEUS SETIFERUS

156

Sanitation Guidelines for the Breaded-Shrimp Industry  

E-print Network

Sanitation Guidelines for the Breaded-Shrimp Industry UNITED STATES DEPARTMENT OF THE INTERIOR FISH OF THE INTERIOR U.S. Fish and Wildlife Service BUREAU OF COMMERCIAL FISHERIES Sanitation Guidelines Dress 12 Habits 13 Supervision 14 in #12;#12;Sanitation Guidelines for the Breaded-Shrimp Industry

157

Model Merger Exercises for Chapter 5: The Brine Shrimp of Mono Lake  

E-print Network

Model Merger Exercises for Chapter 5: The Brine Shrimp of Mono Lake It is often useful to merge two of planktonic and benthic algae, brine shrimp, brine flies and a variety of migrating and nesting bird (see Figure 1) This exercise focuses on the brine shrimp (see Photo 1). Photo 1. The Brine Shrimp (photo

Ford, Andrew

158

Improvement on the technology of producing high quality seawater shrimp broodstocks  

Microsoft Academic Search

Seawater shrimps are high economic valued species. Their natural catch has reached its maximum yield, about 1.6 - 1.8 million ton a year. Shrimp culture is an effective solution to satisfy the continued increasing demand of global markets on this valuable seafood. Shrimp culture, especially the culture of tiger shrimp (Penaeus monodon), is a high profit business, but there are

Nguyen Tac An

2004-01-01

159

Genetic Characteristics of Western North Pacific Sei Whales, Balaenoptera borealis , as Revealed by Microsatellites  

Microsoft Academic Search

Genetic characteristics of sei whales, Balaenoptera borealis, inhabiting the western North Pacific were analyzed at 17 microsatellite loci in a total of 89 whales obtained from the area\\u000a between 37°N–45°N and 147°E–166°E in 2002 (N = 39) and 2003 (N = 50). All the loci analyzed were polymorphic over the samples, some of the loci had more than 10 alleles,

N. Kanda; M. Goto; L. A. Pastene

2006-01-01

160

New binary parameters for the symbiotic recurrent nova T Coronae Borealis  

Microsoft Academic Search

The amplitude of the ellipsoidal variability, the mass function and the evolutionary limits on the component masses have been used to constrain the binary system parameters of T Coronae Borealis. Contrary to all previous studies, our analysis shows that the mass ratio of TCrB is q=M_g\\/M_h~0.6, which implies a low-mass binary system, with the stellar masses M_g~0.7Msolar for the red

K. Belczynski; J. Mikolajewska

1998-01-01

161

White Dwarf Mergers and the Origin of R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

We present a nucleosynthesis study of the merger of a 0.4 M? helium white dwarf with a 0.8 M? carbon-oxygen white dwarf, coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing nucleosynthesis code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars.

Lorén-Aguilar, P.; Longland, R.; José, J.; García-Berro, E.; Althaus, L. G.; Isern, J.

2012-07-01

162

White dwarf mergers and the origin of R Coronae Borealis stars  

E-print Network

We present a nucleosynthesis study of the merger of a 0.4 solar masses helium white dwarf with a 0.8 solar masses carbon-oxygen white dwarf, coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars.

Lorén-Aguilar, P; José, J; García-Berro, E; Althaus, L G; Isern, J

2011-01-01

163

Hydraulic redistribution in Eucalyptus kochii subsp. borealis with variable access to fresh groundwater  

Microsoft Academic Search

Salinity caused by land clearing is an important cause of land degradation in the Western Australian wheatbelt. Returning\\u000a a proportion of the cleared land to higher water use perennial vegetation is one option for reducing or slowing the salinisation\\u000a of land. Over the course of a year patterns of water use by Eucalyptus kochii subsp borealis (C. Gardner) D. Nicolle,

K. Brooksbank; D. A. White; E. J. Veneklaas; J. L. Carter

2011-01-01

164

CO-OCCURRENCE OF WHITE SHRIMP, PENAEUS VANNAMEI, MORTALITIES AND MICROCYSTIN TOXIN IN A SOUTHEASTERN USA SHRIMP FACILITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Various freshwater and marine algal toxins are known to affect plants, fishes, mammals, and invertebrates. During recent mortality events in Texas white shrimp aquaculture ponds, water and shrimp tissue samples were analyzed for cyanobacterial toxins and found to contain microcystin-LR. Cyanoprokar...

165

76 FR 515 - Endangered and Threatened Species, Designation of Critical Habitat for Southern Distinct...  

Federal Register 2010, 2011, 2012, 2013

...occur as bycatch in the ocean shrimp (Pandalus jordani) fishery (Hay et al., 1999; Olsen et al., 2000; NWFSC, 2008; Hannah and Jones, 2009), which seems to indicate that the distribution of these organisms may overlap in the ocean. Spawning...

2011-01-05

166

Immunization with Hypoallergens of Shrimp Allergen Tropomyosin Inhibits Shrimp Tropomyosin Specific IgE Reactivity  

PubMed Central

Designer proteins deprived of its IgE-binding reactivity are being sought as a regimen for allergen-specific immunotherapy. Although shrimp tropomyosin (Met e 1) has long been identified as the major shellfish allergen, no immunotherapy is currently available. In this study, we aim at identifying the Met e 1 IgE epitopes for construction of hypoallergens and to determine the IgE inhibitory capacity of the hypoallergens. IgE-binding epitopes were defined by three online computational models, ELISA and dot-blot using sera from shrimp allergy patients. Based on the epitope data, two hypoallergenic derivatives were constructed by site-directed mutagenesis (MEM49) and epitope deletion (MED171). Nine regions on Met e 1 were defined as the major IgE-binding epitopes. Both hypoallergens MEM49 and MED171 showed marked reduction in their in vitro reactivity towards IgE from shrimp allergy patients and Met e 1-sensitized mice, as well as considerable decrease in induction of mast cell degranulation as demonstrated in passive cutaneous anaphylaxis assay. Both hypoallergens were able to induce Met e 1-recognizing IgG antibodies in mice, specifically IgG2a antibodies, that strongly inhibited IgE from shrimp allergy subjects and Met e 1-sensitized mice from binding to Met e 1. These results indicate that the two designer hypoallergenic molecules MEM49 and MED171 exhibit desirable preclinical characteristics, including marked reduction in IgE reactivity and allergenicity, as well as ability to induce blocking IgG antibodies. This approach therefore offers promises for development of immunotherapeutic regimen for shrimp tropomyosin allergy. PMID:25365343

Wai, Christine Y. Y.; Leung, Nicki Y. H.; Ho, Marco H. K.; Gershwin, Laurel J.; Shu, Shang An; Leung, Patrick S. C.; Chu, Ka Hou

2014-01-01

167

Consumer method to control Salmonella and Listeria species in shrimp.  

PubMed

The purpose of this study was to determine whether the current consumer method of boiling shrimp until floating and pink in color is adequate for destroying Listeria and Salmonella. Shrimp samples were submerged in bacterial suspensions of Listeria and Salmonella for 30 min and allowed to air dry for 1 h under a biosafety cabinet. Color parameters were then measured with a spectrophotometer programmed with the CIELAB system. Twenty-four shrimp samples were divided into groups (days 0, 1, or 2) and stored at 4°C. The samples were treated by placing them in boiling water (100°C) on days 0, 1, and 2. The shrimp were immediately removed from the boiling water once they floated to the surface, and color parameters were measured. Bacterial counts were determined, and the log CFU per gram was calculated. The effect of sodium tripolyphosphate on the color change of cooked shrimp also was determined. Initial bacterial counts on shrimp after air drying were 5.31 ± 0.14 log CFU/g for Salmonella Enteritidis, 5.24 ± 0.31 log CFU/g for Salmonella Infantis, 5.40 ± 0.16 log CFU/g for Salmonella Typhimurium, 3.91 + 0.11 log CFU/g for Listeria innocua, 4.45 ± 0.11 log CFU/g for Listeria monocytogenes (1/2a), and 3.70 ± 0.22 log CFU/g for Listeria welshimeri. On days 0, 1, and 2, all bacterial counts were reduced to nondetectable levels for shrimp samples that floated. The average time for shrimp to float was 96 ± 8 s. The bacterial counts remained at nondetectable levels (<10 log CFU/g) during refrigerated (4°C) storage of cooked shrimp for 2 days. The redness, yellowness, and lightness were significantly higher (P < 0.0001) for the cooked shrimp than for the uncooked shrimp on all days tested. The standard deviation for redness in the cooked shrimp was large, indicating a wide range of pink coloration on all days tested. The results suggest that boiling shrimp until they float will significantly reduce Listeria and Salmonella contamination, but color change is not a good indication of reduction of these pathogens because of the wide natural color variation. PMID:23317857

Edwards, Genevieve; Janes, Marlene; Lampila, Lucina; Supan, John

2013-01-01

168

Description and analysis of the shrimp raceway run for the summer 1990, Shrimp Mariculture Project, Texas A&M University System  

E-print Network

widely used are: -The giant tiger shrimp (P. monodon), cultured in Taiwan, Thailand, Indonesia and the Philippines. It is responsible for 33-: of the world shrimp Farming production. This species is the largest and has the fastest growth rate...

Mena, Luis

1991-01-01

169

EFFECTS OF GROUND ULV (ULTRA-LOW VOLUME) APPLICATIONS OF FENTHION ON ESTUARINE BIOTA. 3. RESPONSE OF CAGED PINK SHRIMP AND GRASS SHRIMP  

EPA Science Inventory

Estuarine grass shrimp (Palaemonetes pugio) and pink shrimp (Penaeus duorarum) were deployed in floating cages to determine if fenthion, in an actual-use application in the field, affected shrimp survival. After four ultra-low-volume ground applications (equivalent to llg/ha or 0...

170

78 FR 19639 - Certain Frozen Warmwater Shrimp From India and Thailand: Notice of Initiation of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From India and Thailand: Notice of Initiation of...frozen warmwater shrimp (shrimp) from India and Thailand. The anniversary month of...David Crespo at (202) 482-3693 (India) and Blaine Wiltse (202)...

2013-04-02

171

75 FR 53947 - Certain Frozen Warmwater Shrimp From Brazil, India, the People's Republic of China, Thailand, and...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From Brazil, India, the People's Republic of China...of certain frozen warmwater shrimp from Brazil, Ecuador, India, the People's Republic...Frozen and Canned Warmwater Shrimp From Brazil, 69 FR 76910 (December 23,...

2010-09-02

172

76 FR 23277 - Certain Frozen Warmwater Shrimp From Brazil, India, the People's Republic of China, Thailand, and...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp From Brazil, India, the People's Republic of China...of certain frozen warmwater shrimp from Brazil, Ecuador, India, the People's Republic...orders on frozen warmwater shrimp from Brazil, the PRC, India, Thailand, and...

2011-04-26

173

75 FR 27299 - Certain Frozen Warmwater Shrimp from Brazil, India, the People's Republic of China and Thailand...  

Federal Register 2010, 2011, 2012, 2013

...Certain Frozen Warmwater Shrimp from Brazil, India, the People's Republic of China...on certain frozen warmwater shrimp from Brazil, India, the People's Republic of China...on certain frozen warmwater shrimp from Brazil, India, the PRC, and Thailand....

2010-05-14

174

COMPARISON OF CARBON AND NITROGEN FLUXES IN TIDEFLAT FOOD WEBS DOMINATED BY BURROWING SHRIMP OR BY CULTURED OYSTERS  

EPA Science Inventory

Two species of indigenous, thalassinid burrowing shrimps are pests to the benthic culture of Pacific oysters (Crassostrea gigas) because deposition of sediment excavated by the shrimps buries or smothers the oysters. Carbaryl pesticide is used to reduce burrowing shrimp densitie...

175

Climatic controls of a keystone understory species, Sasamorpha borealis , and an impact assessment of climate change in Japan  

Microsoft Academic Search

Introduction\\u000a   The aims of this study were to identify the climatic conditions controlling the distribution of Sasamorpha borealis and to assess the impact of climate change on the species in Japan.\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods\\u000a   The relationship between S. borealis distribution and climatic variables in the Japanese Archipelago was explored using classification tree analysis. Potential\\u000a habitat maps under the current and

Ikutaro Tsuyama; Katsuhiro Nakao; Tetsuya Matsui; Motoki Higa; Masahiro Horikawa; Yuji Kominami; Nobuyuki Tanaka

176

Drilling Polar Oceans with the European Research Icebreaker AURORA BOREALIS: the IODP Context  

NASA Astrophysics Data System (ADS)

Polar oceans are characterized by extreme environmental conditions for humans and materials, and have remained the least accessible regions to scientists of the IODP. DSDP and ODP have for long faced specific technical and logistical problems when attempting to drill in ice-covered polar deep-sea basins. The Arctic Ocean and large areas of the high-latitude Southern Ocean remained largely un-sampled by ODP and remain one of the major scientific and technological challenges for IODP. Drilling in these regions has been discussed and anticipated for decades and the scientific rationales are reflected in the science plans of the international Nansen Arctic Drilling Program (NAD) or the Arctic Program Planning Group (APPG) of ODP/IODP, amongst others. More recently, the rationale to investigate the polar oceans in a holistic approach has been outlined by workshops, leading to strategic assessments of the scientific potential and new drilling proposals. The European Polar Board took the initiative to develop a plan for a novel and dedicated research icebreaker with technical capabilities hitherto unrealised. This research icebreaker will enable autonomous operations in the central Arctic Ocean and the Southern Ocean, even during the severest ice conditions in the deep winter, serving all marine disciplines of polar research including scientific drilling: The European Research Icebreaker and Deep-Sea Drilling Vessel AURORA BOREALIS. AURORA BOREALIS is presently planned as a multi-purpose vessel. The ship can be deployed as a research icebreaker in all polar waters during any season of the year, as it shall meet the specifications of the highest ice-class attainable (IACS Polar Code 1) for icebreakers. During the times when it is not employed for drilling, it will operate as the most technically advanced multi-disciplinary research vessel in the Arctic or polar Southern Ocean. AURORA BOREALIS will be a "European scientific flagship facility" (fully open to non-European partners), a multidisciplinary platform for studies ranging from the sub-seafloor into the atmosphere. AURORA BOREALIS was planned for her role in deep-sea drilling in consultation with engineers and technical experts familiar with the program and the operation of these vessels. All techniques currently deployed on IODP expeditions can be implemented onboard the vessel under polar weather and ice conditions, including the full range of re-entry, casing and cementing, and instrumentation options and the entire suite of downhole logging tools. Due to sufficient laboratory space, a full analytical workflow can be easily established comparable to existing permanent platforms, including clean rooms, diverse scanning and logging or incubation facilities. While the vessel is equipped with a dedicated deep-sea drilling rig, other coring and drilling techniques can be employed if needed (e.g. Rockdrill, MEBO, large diameter Kasten cores). AURORA BOREALIS is fitted to operate a CALYPSO Piston Coring System in polar waters. Future mud-return systems under consideration and testing for IODP to provide controlled borehole conditions in difficult facies are compatible with the layout of AURORA BOREALIS. The berthing capacity of 120 personnel total (scientists, technical support and crew) allows to accommodate a sufficient number of science party members offshore. The present scientific implementation documents plan for about one polar scientific drilling expedition per year in a to-be-determined configuration. As the vessel is a multi-dsiciplinary platform, operations for the entire year are not dependant on drilling operations alone. While principal access to the vessel will be based on a competitive proposal review and evaluation system, the allocation of timeslots specifically for drilling would preferably be given over to IODP handling and planning systems in a cooperative mode using the strengths and capacitites of the future program. Depending on interests and needs of the scientific communities a preferential focus in non-drilling expedition planning could be e

Lembke-Jene, Lester; Wolff-Boenisch, Bonnie; Azzolini, Roberto; Thiede, Joern; Biebow, Nicole; Eldholm, Olav; Egerton, Paul

2010-05-01

177

MAPPING BURROWING SHRIMP AND SEAGRASS IN YAQUINA ESTUARY  

EPA Science Inventory

Burrowing shrimp and seagrasses create extensive intertidal and shallow subtidal habitats within Pacific NW estuaries. Maps of their populations are useful to inform estuarine managers of locations that deserve special consideration for conservation, and to inform oyster farmers...

178

Editor's Comments On Eating Shrimp, and Some Other Matters  

E-print Network

\\,el Tap water. Salt bay leaf or IWO. Cloves. Olher spices accordm!! 10 Ihe C,)"~\\\\\\ him One COP) of ) e not content with the incomparable flavor of the shrimp itself, and icy beer. It would be ungentlemanly

179

ADDITIONAL REFERENCES ON THE BIOLOGY OF SHRIMP, FAMILY PENAEIDAE 1  

E-print Network

. 'VISBY. 1964. Effects of light and moon phase on the be- havior of pink shrimp. Proc. Gulf Carib. Fish. Divulg. 6(57), "" pp. 101 #12;ALDRICH, DAVID V. 1963. Physiology and behavior program. In Biologi- cal

180

GENETIC CHARACTERIZATION OF A BURROWING SHRIMP (NEOTRYPAEA CALIFORNIENSIS)  

EPA Science Inventory

Ghost shrimp, (Neotypaea californiensis) are burrowers, whose bioturbation and sediment destabilizations have a negative effect on mariculture of the commercially important oyster (Crassostrea gigas). Oyster farmers in Washington and Oregon estuaries have been poisoning these shr...

181

DISSOLVED AIR FLOTATION TREATMENT OF GULF SHRIMP CANNERY WASTEWATER  

EPA Science Inventory

This study reports on the operation of a plant scale dissolved air flotation system installed to define and evaluate attainable shrimp cannery wastewater treatment levels. The system was operated in all three modes of DAF pressurization. Destabilizing coagulants investigation inc...

182

Economic feasibility of commercial shrimp farming in Texas  

E-print Network

with Critical Factor for Net Cash Flow 26 Format of Net Present Value Analysis with Critical Factors for Total Assets 27 Wholesale Shrimp Prices for 51-65 Count P. setiferus (white shrimp) 1/68 ? June, 1$7$ CHAPTER I INTRODUCTION The exponential growth... Literature Review Methodology FACTORS AFFECTING ASSETS, OPERATING EXPENSES AND REVENUE Assets Operating Expenses De scription o f Revenue 9 16 21 III THE MODEL. . . . . . . . . . . . . . . 2$ Data Inputs for the Mod, el Land and Improvements...

Williams, Robert James

2012-06-07

183

NORMAL POSTMORTEM CHANGES IN THE BROWN SHRIMP, PENAEUS AZTECUSI  

Microsoft Academic Search

A study was carried out to determine the normal rates and patterns of gross and histologic postmortem changes in the brown shrimp (Penaells a~.le(,lIs Ives). Experimental shrimp were held at 10°, 20°, or 30°C in water-saturated air or in seawater at a salinity of 30%0. Observations were made at O. 2. 4, 8, 12, 24, 48, and 72 h postmortem.

DONALD V. LIGHTNER

184

Diurnal and nocturnal catchability of Kuwait's commercial shrimps  

Microsoft Academic Search

In descending order of importance, the shrimps Penaeus semisulcatus De Haan, 1844; Metapenaeus affinis (H. Milne-Edwards, 1837); and Parapenaeopsis stylifera (H. Milne-Edwards, 1837) account for over 95% of Kuwait's commercial landings. Throughout its range, P. semisulcatus is nocturnal, but Kuwait trawlers are active 24h a day during season. Historically, all scientific shrimp surveys in Kuwait have been conducted during daylight

J. M. Bishop; Y. Ye; A. H. Alsaffar; H. M. Al-Foudari; S. Al-Jazzaf

2008-01-01

185

Economic and financial implications of shrimp farming in West Texas  

E-print Network

Analysis. DESCRIPTION OF AQUACULTURE FACILITY Pond Construction Equipment Fixed Costs. Operational Costs Shrimp Price Biological Parameters RESULTS. 17 18 19 21 22 26 28 30 32 32 33 34 37 Deterministic Implications. Sensitivity... Illustration of mean, maximum, and minimum annual net returns for a simulated shrimp farm, 25 separate iterations. . . . . . . . . . . . . . . 50 INTRODUCTION West Texas is searching for new economic opportunities. Aquaculture using saline ground water may...

Britt, David Westbrook

1995-01-01

186

Detection of virus in shrimp using digital color correlation  

NASA Astrophysics Data System (ADS)

Detection of virus in shrimp tissue using digital color correlation is presented. Phase filters in three channels (red, green and blue) were used in order to detect HPV virus like target. These first results obtained showed that is possible to detect virus in shrimp tissue. More research must be made with color correlation in order to consider natural morphology of the virus, color, scale and rotation and noise in the samples.

Alvarez-Borrego, Josue; Chavez-Sanchez, Cristina; Bueno-Ibarra, Mario A.

1999-07-01

187

Enhanced Cellular Immunity in Shrimp (Litopenaeus vannamei) after ‘Vaccination’  

PubMed Central

It has long been viewed that invertebrates rely exclusively upon a wide variety of innate mechanisms for protection from disease and parasite invasion and lack any specific acquired immune mechanisms comparable to those of vertebrates. Recent findings, however, suggest certain invertebrates may be able to mount some form of specific immunity, termed ‘specific immune priming’, although the mechanism of this is not fully understood (see Textbox S1). In our initial experiments, either formalin-inactivated Vibrio harveyi or sterile saline were injected into the main body cavity (haemocoel) of juvenile shrimp (Litopenaeus vannamei). Haemocytes (blood cells) from V. harveyi-injected shrimp were collected 7 days later and incubated with a 1?1 mix of V. harveyi and an unrelated Gram positive bacterium, Bacillus subtilis. Haemocytes from ‘vaccinated’ shrimp showed elevated levels of phagocytosis of V. harveyi, but not B. subtilis, compared with those from saline-injected (non-immunised) animals. The increased phagocytic activity was characterised by a significant increase in the percentage of phagocytic cells. When shrimp were injected with B. subtilis rather than vibrio, there was no significant increase in the phagocytic activity of haemocytes from these animals in comparison to the non-immunised (saline injected) controls. Whole haemolymph (blood) from either ‘immunised’ or non-immunised’ shrimp was shown to display innate humoral antibacterial activity against V. harveyi that was absent against B. subtilis. However, there was no difference in the potency of antibacterial activity between V. harveyi-injected shrimp and control (saline injected) animals showing that ‘vaccination’ has no effect on this component of the shrimp's immune system. These results imply that the cellular immune system of shrimp, particularly phagocytosis, is capable of a degree of specificity and shows the phenomenon of ‘immune priming’ reported by other workers. However, in agreement with other studies, this phenomenon is not universal to all potential pathogens. PMID:21698190

Roberts, Emily C.; Shields, Robin J.; Wardle, Robin; Rowley, Andrew F.

2011-01-01

188

Hydrocarbon analysis of shrimp from oil polluted waters  

E-print Network

HYDROCARBON ANALYSIS OF SHRIMP FROM OIL POLLUTED WATERS A Thesis by BERNARD JOHN DEWITT III Submitted to the Graduate College of Texas A&M University in partial fulfilment of the requirement for the degree of MASTER OF SCIENCE May 1982... Major Subject: Food Science and Technology HYDROCARBON ANALYSIS OF SHRIMP FROM OIL POLLUTED WATERS A Thesis BERNARD JOHN DEWITT III Approved as to style and content by: (Chairman of Committee) (Member) (Member) (Head of apartment) May 1982...

DeWitt, Bernard John

2012-06-07

189

Probes of large-scale structure in the Corona Borealis region  

NASA Technical Reports Server (NTRS)

The present redshift survey of the Corona Borealis region encompasses redshifts, magnitudes and positions for 83 galaxies covering a 16.4 sq deg region; a complementary survey covers 39.2 sq deg, is complete to m(B)0 of 15.5, and encompasses 37 galaxies. The combined survey furnishes further support for the 'bubble-like' geometry revealed by the shallower CfA survey. The redshift distribution obtained is noted to be very similar to that in the neighboring Bootes region. The structure of voids and surfaces in the galaxy distribution is insensitive to luminosity for M(B)0 of less than about -17.4.

Postman, M.; Huchra, J. P.; Geller, M. J.

1986-01-01

190

Discovery of Five New R Coronae Borealis Stars in the MACHO Galactic Bulge Lightcurve Database  

NASA Astrophysics Data System (ADS)

We have identified 5 new R Coronae Borealis (RCB) stars in the Galactic bulge, using the MACHO photometry database, raising the total number of known Galactic RCB stars to 40. We have obtained spectra to confirm the identifications. The fact that four out of the 5 newly identified RCB stars are ``cool'' rather than ``warm'' suggests the preponderance of warm RCB stars among the existing sample may be a selection bias. Using the volume of the surveyed field, we estimate the total number of Galactic RCB stars to be about 700. This project was supported by the NSF/REU grant AS T-0097694 and the Nantucket Maria Mitchell Association.

Zaniewski, A. M.; Clayton, G. C.; Welch, D. L.; Gordon, K. D.; Minniti, D.; Cook, K.

2004-12-01

191

Hydrologic activity during late Noachian and Early Hesperian downwarping of Borealis Basin, Mars  

NASA Technical Reports Server (NTRS)

Pronounced global volcanism as well as fracturing and erosion along the highland/lowland boundary (HLB) during the Late Noachian (LN) and Early Hesperian (EH) led McGill and Dimitriou to conclude that the Borealis basin formed tectonically during this period. This scenario provides a basis for interpretation of the initiation and mode of formation of erosional and collapse features along the HLB. The interpretation, in turn, is integral to hypotheses regarding the development of ancient lakes (or an ocean) and their impact on the climate history of Mars. Hydrologic features of Mars are discussed along with their implications for paleolakes and climate history.

Tanaka, Kenneth L.

1991-01-01

192

THE HOT R CORONAE BOREALIS STAR DY CENTAURI IS A BINARY  

SciTech Connect

The remarkable hot R Coronae Borealis (RCB) star DY Cen is revealed to be the first and only binary system to be found among the RCB stars and their likely relatives, including the extreme helium stars and the hydrogen-deficient carbon stars. Radial velocity determinations from 1982 to 2010 have shown that DY Cen is a single-lined spectroscopic binary in an eccentric orbit with a period of 39.67 days. It is also one of the hottest and most H-rich member of the class of RCB stars. The system may have evolved from a common envelope to its current form.

Kameswara Rao, N. [543, 17th Main, IV Sector, HSR Layout, Bangalore 560102 (India); Lambert, David L.; McArthur, Barbara [W. J. McDonald Observatory, University of Texas, Austin, TX 78712-1083 (United States); Garcia-Hernandez, D. A. [Instituto de Astrofisica de Canarias, C/Via Lactea s/n, E-38205 La Laguna (Spain); Simon Jeffery, C. [Armagh Observatory, College Hill, Armagh BT61 9DG (United Kingdom); Woolf, Vincent M., E-mail: nkrao@iiap.res.in, E-mail: dll@astro.as.utexas.edu, E-mail: agarcia@iac.es [Physics Department, University of Nebraska at Omaha, NE 68182-0266 (United States)

2012-11-20

193

Are the R Coronae Borealis Stars Produced by White Dwarf Mergers?  

NASA Astrophysics Data System (ADS)

The R Coronae Borealis (RCB) stars are rare hydrogen-deficient, carbon-rich supergiants. Two evolutionary scenarios have been suggested, a double degenerate merger of two white dwarfs (WDs), or a final helium shell flash in a PN central star. The evidence pointing toward a WD merger or a FF origin for RCB stars is contradictory. The population of RCB stars in the Galaxy may be consistent with the number of He/CO WD mergers. If so, this would be an exciting result since RCB stars may be low-mass analogs of Type Ia SNe.

Clayton, G. C.

2013-01-01

194

The Hot R Coronae Borealis Star DY Centauri is a Binary  

NASA Astrophysics Data System (ADS)

The remarkable hot R Coronae Borealis (RCB) star DY Cen is revealed to be the first and only binary system to be found among the RCB stars and their likely relatives, including the extreme helium stars and the hydrogen-deficient carbon stars. Radial velocity determinations from 1982 to 2010 have shown that DY Cen is a single-lined spectroscopic binary in an eccentric orbit with a period of 39.67 days. It is also one of the hottest and most H-rich member of the class of RCB stars. The system may have evolved from a common envelope to its current form.

Kameswara Rao, N.; Lambert, David L.; García-Hernández, D. A.; Jeffery, C. Simon; Woolf, Vincent M.; McArthur, Barbara

2012-11-01

195

Decline and local extinction of Caribbean eusocial shrimp.  

PubMed

The tropical shrimp genus Synalpheus includes the only eusocial marine animals. In much of the Caribbean, eusocial species have dominated the diverse fauna of sponge-dwelling shrimp in coral rubble for at least the past two decades. Here we document a recent, dramatic decline and apparent local extinction of eusocial shrimp species on the Belize Barrier Reef. Our collections from shallow reefs in central Belize in 2012 failed to locate three of the four eusocial species formerly abundant in the area, and showed steep declines in colony size and increases in frequency of queenless colonies prior to their disappearance. Concordant with these declines, several nonsocial, pair-forming Synalpheus species increased in frequency. The decline in eusocial shrimp is explained in part by disappearance of two sponge species on which they specialize. Eusocial shrimp collections from Jamaica in 2012 showed similar patterns of decline in colony size and increased queenlessness compared with prior Jamaican collections. The decline and local extinction of eusocial shrimp happened against a backdrop of changes in coral assemblages during recent decades, and may reflect changes in abundance and quality of dead coral substratum and succession of the diverse cryptic organisms living within it. These changes document potentially worrisome declines in a unique taxon of eusocial marine animals. PMID:23418429

Duffy, J Emmett; Macdonald, Kenneth S; Hultgren, Kristin M; Chak, Tin Chi Solomon; Rubenstein, Dustin R

2013-01-01

196

Comparative spring mechanics in mantis shrimp.  

PubMed

Elastic mechanisms are fundamental to fast and efficient movements. Mantis shrimp power their fast raptorial appendages using a conserved network of exoskeletal springs, linkages and latches. Their appendages are fantastically diverse, ranging from spears to hammers. We measured the spring mechanics of 12 mantis shrimp species from five different families exhibiting hammer-shaped, spear-shaped and undifferentiated appendages. Across species, spring force and work increase with size of the appendage and spring constant is not correlated with size. Species that hammer their prey exhibit significantly greater spring resilience compared with species that impale evasive prey ('spearers'); mixed statistical results show that species that hammer prey also produce greater work relative to size during spring loading compared with spearers. Disabling part of the spring mechanism, the 'saddle', significantly decreases spring force and work in three smasher species; cross-species analyses show a greater effect of cutting the saddle on the spring force and spring constant in species without hammers compared with species with hammers. Overall, the study shows a more potent spring mechanism in the faster and more powerful hammering species compared with spearing species while also highlighting the challenges of reconciling within-species and cross-species mechanical analyses when different processes may be acting at these two different levels of analysis. The observed mechanical variation in spring mechanics provides insights into the evolutionary history, morphological components and mechanical behavior, which were not discernible in prior single-species studies. The results also suggest that, even with a conserved spring mechanism, spring behavior, potency and component structures can be varied within a clade with implications for the behavioral functions of power-amplified devices. PMID:23239886

Patek, S N; Rosario, M V; Taylor, J R A

2013-04-01

197

Spectroscopic and photometric observations of the R Coronae Borealis stars S Apodis and RZ Normae throughout their recent declines  

Microsoft Academic Search

Spectroscopic and photometric observations of two R Coronae Borealis (RCB) stars, S Apodis and RZ Normae, have been obtained during the decline phase of each of these stars. Although the declines have very different global characteristics -- the depth of the decline in brightness is respectively 6 and 2 mag in S Aps and RZ Nor -- there are some

Lj. Skuljan; P. L. Cottrell

1999-01-01

198

High-resolution polarization observations inside spectral lines of magnetic Ap stars. I. Instrumentation and observations of. beta. Coronae Borealis  

Microsoft Academic Search

We have constructed a coude photon-counting polarimeter capable of attaining (with a Fabry-Perot interferometer) a high resolution. A description of the instrument is given, with a discussion of various sources of systematic error in the polarimetry. Observations of linear and circular polarization in the spectrum of the Ap star ..beta.. Coronae Borealis, throughout the magnetic cycle, are obtained across an

E. F. Borra; A. H. Vaughan

1977-01-01

199

Biology and life cycle of Natatolana borealis Lilj.1851, a scavenging isopod from the continental slope of the Mediterranean  

Microsoft Academic Search

The biology of Natatolana borealis, a deep-sea (?500 m) scavenging isopod that lives on the continental slope of Mediterranean canyons, was studied in the field and in the laboratory. Animals were collected at two stations using a baited trap. Whatever the site at which the animals were collected, a strong correlation was always found to exist between their length and

R. A. Kaïm-Malka

1997-01-01

200

The 203 kbp Mitochondrial Genome of the Phytopathogenic Fungus Sclerotinia borealis Reveals Multiple Invasions of Introns and Genomic Duplications  

PubMed Central

Here we report the complete sequence of the mitochondrial (mt) genome of the necrotrophic phytopathogenic fungus Sclerotinia borealis, a member of the order Helotiales of Ascomycetes. The 203,051 bp long mtDNA of S. borealis represents one of the largest sequenced fungal mt genomes. The large size is mostly determined by the presence of mobile genetic elements, which include 61 introns. Introns contain a total of 125,394 bp, are scattered throughout the genome, and are found in 12 protein-coding genes and in the ribosomal RNA genes. Most introns contain complete or truncated ORFs that are related to homing endonucleases of the LAGLIDADG and GIY-YIG families. Integrations of mobile elements are also evidenced by the presence of two regions similar to fragments of inverton-like plasmids. Although duplications of some short genome regions, resulting in the appearance of truncated extra copies of genes, did occur, we found no evidences of extensive accumulation of repeat sequences accounting for mitochondrial genome size expansion in some other fungi. Comparisons of mtDNA of S. borealis with other members of the order Helotiales reveal considerable gene order conservation and a dynamic pattern of intron acquisition and loss during evolution. Our data are consistent with the hypothesis that horizontal DNA transfer has played a significant role in the evolution and size expansion of the S. borealis mt genome. PMID:25216190

Mardanov, Andrey V.; Beletsky, Alexey V.; Kadnikov, Vitaly V.; Ignatov, Alexander N.; Ravin, Nikolai V.

2014-01-01

201

78 FR 54912 - Frozen Warmwater Shrimp from Indonesia and Thailand; Termination of Investigations  

Federal Register 2010, 2011, 2012, 2013

...Final)] Frozen Warmwater Shrimp from Indonesia and Thailand; Termination of Investigations...the subject investigations concerning Indonesia (78 FR 50379) and Thailand (78 FR...concerning frozen warmwater shrimp from Indonesia and Thailand (investigation Nos....

2013-09-06

202

78 FR 72635 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Rescission of Antidumping...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Rescission of Antidumping Duty New Shipper Review...frozen warmwater shrimp from the Socialist Republic of Vietnam (``Vietnam'') covering the period February 1, 2013...

2013-12-03

203

78 FR 59650 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation of Antidumping...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation of Antidumping Duty New Shipper Review...frozen warmwater shrimp from the Socialist Republic of Vietnam (``Vietnam'') meets the statutory and regulatory...

2013-09-27

204

75 FR 27705 - Certain Frozen Warmwater Shrimp from the Socialist Republic of Vietnam: Extension of Final...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp from the Socialist Republic of Vietnam: Extension of Final Results of Antidumping Duty New...shrimp'') from the Socialist Republic of Vietnam (``Vietnam''). This review covers the period February...

2010-05-18

205

75 FR 60730 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation of Antidumping...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation of Antidumping Duty New Shipper Review...shrimp'') from the Socialist Republic of Vietnam (``Vietnam''), received on August 26, 2010, meets the...

2010-10-01

206

75 FR 844 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Preliminary Results of Antidumping...shrimp'') from the Socialist Republic of Vietnam (``Vietnam''). This review covers the period February...

2010-01-06

207

76 FR 36519 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Final...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Final Results of Antidumping Duty Administrative...frozen warmwater shrimp from the Socialist Republic of Vietnam (``Vietnam''). The review covers the period February...

2011-06-22

208

75 FR 55740 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Preliminary...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Preliminary Results of Antidumping...frozen warmwater shrimp from the Socialist Republic of Vietnam (``Vietnam''). The review covers the period February...

2010-09-14

209

76 FR 16384 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation of Antidumping...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Initiation of Antidumping Duty New Shipper Review...shrimp'') from the Socialist Republic of Vietnam (``Vietnam''), received on February 28, 2011, meets...

2011-03-23

210

78 FR 15699 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Preliminary Results of...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Preliminary Results of Antidumping Duty Administrative...frozen warmwater shrimp from the Socialist Republic of Vietnam (``Vietnam'') for the period of review (``POR'')...

2013-03-12

211

MORE THAN JUST BAIT: BURROWING SHRIMP AS ECOSYSTEM ENGINEERS IN OREGON ESTUARIES - SEPTEMBER 2006  

EPA Science Inventory

Burrowing shrimp may be most widely known as excellent fishing bait, but they also play important roles in estuaries of the Pacific Northwest. These shrimps strongly affect carbon and nutrient cycling, phytoplankton abundance, food web structure and dynamics, sediment stability,...

212

RESPONSE OF GHOST SHRIMP (NEOTRYPAEA CALIFORNIENSIS) BIOTURBATION TO ORGANIC MATTER ENRICHMENT OF ESTUARINE INTERTIDAL SEDIMENTS  

EPA Science Inventory

Populations of burrowing shrimp (Neotrypaea californiensis and Upogebia p;ugettensis) are the dominant invertebrate fauna on Pacific estuarine tide flats, occupying >80% of intertidal area in some estuaries. Burrowing shrimp are renowned for their bioturbation of intertidal sedi...

213

ENHANCED ORGANIC MATTER REMINERALIZATION AND NUTRIENT TURNOVER BY POPULATIONS OF BURROWING SHRIMP IN YAQUINA BAY, OR  

EPA Science Inventory

Burrowing, or thalassinid, shrimp structure large areas of intertidal habitat of Pacific Northwest estuaries. This field study utilized a combination of anoxic incubations, porewater dialysis peepers, and benthic chambers to quantify the role of burrowing shrimp species on OM dec...

214

Electrical coupling and innexin expression in the stomatogastric ganglion of the crab Cancer borealis.  

PubMed

Gap junctions are intercellular channels that allow for the movement of small molecules and ions between the cytoplasm of adjacent cells and form electrical synapses between neurons. In invertebrates, the gap junction proteins are coded for by the innexin family of genes. The stomatogastric ganglion (STG) in the crab Cancer borealis contains a small number of identified and electrically coupled neurons. We identified Innexin 1 (Inx1), Innexin 2 (Inx2), Innexin 3 (Inx3), Innexin 4 (Inx4), Innexin 5 (Inx5), and Innexin 6 (Inx6) members of the C. borealis innexin family. We also identified six members of the innexin family from the lobster Homarus americanus transcriptome. These innexins show significant sequence similarity to other arthropod innexins. Using in situ hybridization and reverse transcriptase-quantitative PCR (RT-qPCR), we determined that all the cells in the crab STG express multiple innexin genes. Electrophysiological recordings of coupling coefficients between identified pairs of pyloric dilator (PD) cells and PD-lateral posterior gastric (LPG) neurons show that the PD-PD electrical synapse is nonrectifying while the PD-LPG synapse is apparently strongly rectifying. PMID:25210156

Shruti, Sonal; Schulz, David J; Lett, Kawasi M; Marder, Eve

2014-12-01

215

High-resolution spectroscopy of the R Coronae Borealis Star V Coronae Australis  

E-print Network

Optical high-resolution spectra of the R Coronae Borealis star V CrA at light maximum and during minimum light arediscussed. Abundance analysis confirms previous results showing that V CrA has the composition of the small subclass of R Coronae Borealis (RCB) stars know as `minority' RCBs, i.e., the Si/Fe and S/Fe ratios are 100 times their solar values. A notable novel result for RCBs is the detection of the 1-0 Swan system $^{12}$C$^{13}$C bandhead indicating that $^{13}$C is abundant: spectrum synthesis shows that $^{12}$C/$^{13}$C is about 3 to 4. Absorption line profiles are variable at maximum light with some lines showing evidence of splitting by about 10 km s$^{-1}$. A spectrum obtained as the star was recovering from a deep minimum shows the presence of cool C$_2$ molecules with a rotational temperature of about 1200K, a temperature suggestive of gas in which carbon is condensing into soot. The presence of rapidly outflowing gas is shown by blue-shifted absorption components of the Na {\\sc i} D and K ...

Rao, N Kameswara

2007-01-01

216

High-resolution spectroscopy of the R Coronae Borealis Star V Coronae Australis  

E-print Network

Optical high-resolution spectra of the R Coronae Borealis star V CrA at light maximum and during minimum light arediscussed. Abundance analysis confirms previous results showing that V CrA has the composition of the small subclass of R Coronae Borealis (RCB) stars know as `minority' RCBs, i.e., the Si/Fe and S/Fe ratios are 100 times their solar values. A notable novel result for RCBs is the detection of the 1-0 Swan system $^{12}$C$^{13}$C bandhead indicating that $^{13}$C is abundant: spectrum synthesis shows that $^{12}$C/$^{13}$C is about 3 to 4. Absorption line profiles are variable at maximum light with some lines showing evidence of splitting by about 10 km s$^{-1}$. A spectrum obtained as the star was recovering from a deep minimum shows the presence of cool C$_2$ molecules with a rotational temperature of about 1200K, a temperature suggestive of gas in which carbon is condensing into soot. The presence of rapidly outflowing gas is shown by blue-shifted absorption components of the Na {\\sc i} D and K {\\sc i} 7698 \\AA resonance lines.

N. Kameswara Rao; David L. Lambert

2007-10-26

217

An economic model incorporating shrimp growth and water quality parameters into a budget-simulation  

E-print Network

, the penaeid shrimps, have become poten- tial culture organisms along the Texas Gulf Coast. A high volume of sales is feasible since shrimp may be cultured in densities of approximately 40, 000 shrimo per acre (Parker) and since there ap- pears to be a high... of wind, water turnover rates, photosynthesis, decomposition, phytoplanktonic res- piration, and shrimp respiration. Several shrimp-growth models are currently being developed at Texas A&M University. Each of these models is concerned with dif- ferent...

Hanson, Jerrell Scott

2012-06-07

218

Quality perceptions of stakeholders in Beninese export-oriented shrimp chain.  

PubMed

In recent years, the Beninese shrimp sector has faced a ban on export to the European Union due to lack of compliance with food safety standards. The present study aimed at obtaining insight into the factors that determine shrimp quality and safety in Benin. A survey was conducted to investigate the relationships between stakeholders, the conditions under which shrimps are handled at fishing areas and processed at shrimp plants, and the stakeholders' perceptions of quality. A total of 325 fishermen, 128 intermediate traders, 12 collectors, and 3 shrimp processing plant managers were interviewed face to face. The results showed that various specific relations existed between the stakeholders. For example, loyalty was ensured by family relationships, or incentives were provided to ensure a supply of shrimps between stakeholders. Shrimp handling practices during the steps prior to shrimp processing at the plants were not in agreement with the requirements of the European regulations. For example, shrimps were kept at ambient temperature (28 ± 1°C) by 94.1% of fishermen and 60.9% of intermediate traders. Shrimps were also stored in inappropriate holding containers and washed with nonpotable water. Fishermen, intermediate traders, and collectors considered shrimp size and texture their priority quality attributes, whereas plant managers considered shrimp appearance (freshness) and texture their priority quality attributes. This survey demonstrated that the steps prior to shrimp processing at the plants are the critical steps for shrimp quality and safety because of temperature abuse and inappropriate hygienic conditions. There is a need to communicate and provide incentives for the stakeholders in the first part of the chain to give priority to shrimp freshness. Moreover, training in Good Fishing Practices and safe food handling practices and evaluation of compliance with the practices through monitoring will contribute to better shrimp quality and safety management. PMID:25198861

Dabade, D Sylvain; den Besten, Heidy M W; Azokpota, Paulin; Nout, M J Rob; Hounhouigan, D Joseph; Zwietering, Marcel H

2014-09-01

219

Coming out of their homesteads? : Employment for rural women in shrimp aquaculture in coastal Bangladesh  

Microsoft Academic Search

Bangladesh has experienced a rapid expansion of shrimp farming in the coastal regions in recent years. The increase in both area and production has been influenced by the financial profit motive of rural farmers coupled with high international demands for shrimps and ecological congeniality for shrimp aquaculture. In the past the traditional farming systems in the coastal belts of Bangladesh

M. Akhter Hamid; Mohammad Alauddin

1998-01-01

220

50 CFR 622.208 - Minimum mesh size applicable to rock shrimp off Georgia and Florida.  

Code of Federal Regulations, 2013 CFR

...false Minimum mesh size applicable to rock shrimp off Georgia and Florida. 622...208 Minimum mesh size applicable to rock shrimp off Georgia and Florida. (a) The minimum mesh size for the cod end of a rock shrimp trawl net in the South...

2013-10-01

221

50 CFR 622.19 - South Atlantic rock shrimp limited access off Georgia and Florida.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false South Atlantic rock shrimp limited access off Georgia and Florida...Limitations § 622.19 South Atlantic rock shrimp limited access off Georgia and Florida...For a person aboard a vessel to fish for rock shrimp in the South Atlantic EEZ off...

2010-10-01

222

50 CFR 622.19 - South Atlantic rock shrimp limited access off Georgia and Florida.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false South Atlantic rock shrimp limited access off Georgia and Florida...Limitations § 622.19 South Atlantic rock shrimp limited access off Georgia and Florida...For a person aboard a vessel to fish for rock shrimp in the South Atlantic EEZ off...

2011-10-01

223

50 CFR 622.19 - South Atlantic rock shrimp limited access off Georgia and Florida.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false South Atlantic rock shrimp limited access off Georgia and Florida...Limitations § 622.19 South Atlantic rock shrimp limited access off Georgia and Florida...For a person aboard a vessel to fish for rock shrimp in the South Atlantic EEZ off...

2012-10-01

224

Environmental mutagenicity and toxicity caused by sodium metabisulfite in sea shrimp harvesting in Piauí, Brazil  

Microsoft Academic Search

Sodium metabisulfite is used in marine shrimp harvesting to prevent the occurrence of black spots. Shrimps are soaked in a sodium metabisulfite solution in ice, which is disposed of in sewages that run into marine canals, creating an environmental hazard. This study evaluates the toxicity and mutagenicity caused by sodium metabisulfite in sea waters and sediments collected in a shrimp

Ivana Mara da Costa Machado Matos Carvalho; Ana Amélia Melo Cavalcante; Alisson Ferreira Dantas; Danilo Leôncio Aguiar Pereira; Francisco Cézar Costa Rocha; Francisco Massal de Oliveira; Juliana Da Silva

2011-01-01

225

78 FR 76106 - Certain Frozen Warmwater Shrimp From the People's Republic of China: Notice of Final...  

Federal Register 2010, 2011, 2012, 2013

...Administration [A-570-893] Certain Frozen Warmwater Shrimp From the People's...antidumping duty order on certain frozen warmwater shrimp from the People's...Circumstances Review: Certain Frozen Warmwater Shrimp from the People's...available, in accordance with section 776(a) and (b) of...

2013-12-16

226

Mangroves as filters of shrimp pond effluent: predictions and biogeochemical research needs  

Microsoft Academic Search

Preliminary estimates of the ratio of mangrove forest: shrimp pond area necessary to remove nutrients from shrimp pond effluent are made using budgets of nitrogen and phosphorus output for semi-intensive and intensive shrimp ponds combined with estimates of total net primary production in Rhizophora-dominated mangrove forests in tropical coastal areas. If effluent is delivered directly to mangrove forest plots, it

A. I. Robertson; M. J. Phillips

1995-01-01

227

RADIATION PASTEURIZATION OF SHRIMP. Final Summary Report for the Period, January-December 1962  

Microsoft Academic Search

Radiation processing of shrimp was investigated as a means of extending ; refrigerated storage life from 15 to 30 days or longer. Doses of Co⁶° ; gamma radiation of 50,000 to 100,000 rads resulted in an increase in the iced ; storage life of shrimp of from 2 to 7 weeks, as compared to unirradiated controls. ; The shrimp were

A. F. Novak; J. A. Liuzzo

1963-01-01

228

Metals in Shrimp Culture Areas from the Gulf of Fonseca, Central America. I. Sediments  

Microsoft Academic Search

Shrimp aquaculture is a prominent industrial activity in the Gulf of Fonseca, which is shared by Honduras, Nicaragua and El Salvador. The shrimp culture area in Honduras is widely extended and mainly located in the Departments of Valle and Choluteca, receiving waters from Choluteca, Sampile, Goascoran, Nacaome and Negro Rivers. Three thousands tons of shrimps were produced during 1993. In

G. Carbonell; C. Ramos; J. V. Tarazona

1998-01-01

229

Strong population genetic structure and larval dispersal capability of the burrowing ghost shrimp (Neotrypaea californiensis)  

EPA Science Inventory

The burrowing ghost shrimp, Neotrypaea californiensis, is a vital member of the estuarine benthic community. Dense populations of shrimp are found in the major estuaries of Washington and Oregon. Our study determines the genetic structure of shrimp populations in order to gain ...

230

77 FR 36998 - Proposed Information Collection; Comment Request; Mandatory Shrimp Vessel and Gear...  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Shrimp Vessel and Gear Characterization Survey AGENCY...as required by the Paperwork Reduction Act of 1995. DATES: Written...for the Gulf Shrimp Vessel and Gear Characterization Form may be...annual Gulf Shrimp Vessel and Gear Characterization Form....

2012-06-20

231

78 FR 40436 - Proposed Information Collection; Comment Request; Mandatory Shrimp Vessel and Gear...  

Federal Register 2010, 2011, 2012, 2013

...Mandatory Shrimp Vessel and Gear Characterization Survey AGENCY...as required by the Paperwork Reduction Act of 1995. DATES: Written...for the Gulf Shrimp Vessel and Gear Characterization Form may be...annual Gulf Shrimp Vessel and Gear Characterization Form....

2013-07-05

232

Antibacterial activity in four marine crustacean decapods.  

PubMed

A search for antibacterial activity in different body-parts of Pandalus borealis (northern shrimp), Pagurus bernhardus (hermit crab), Hyas araneus (spider crab) and Paralithodes camtschatica (king crab) was conducted. Dried samples were extracted with 60% (v/v) acetonitrile, containing 0.1% (v/v) trifluoroacetic acid, and further extracted and concentrated on C18 cartridges. Eluates from the solid phase extraction were tested for antibacterial, lysozyme and haemolytic activity. Antibacterial activity against Escherichia coli, Vibrio anguillarum, Corynebacterium glutamicum and Staphylococcus aureus was detected in extracts from several tissues in all species tested, but mainly in the haemolymph and haemocyte extracts. V. anguillarum and C. glutamicum were generally the most sensitive micro-organisms. In P. borealis and P. bernhardus most of the active fractions were not affected by proteinase K treatment, while in H. araneus and P. camtschatica most fractions were sensitive to proteinase K treatment, indicating antibacterial factors of proteinaceous nature. In P. bernhardus the active fractions were generally heat labile, whereas in H. araneus the activities were resistant to heat. Differences between active extracts regarding hydrophobicity and sensitivity for heat and proteinase K treatment indicate that several compounds are responsible for the antibacterial activities detected. Lysozyme-like activity could be detected in some fractions and haemolytic activity against human red blood cells could be detected in haemolymph/haemocyte and exoskeleton extracts from all species tested. PMID:12194450

Haug, Tor; Kjuul, Anita K; Stensvåg, Klara; Sandsdalen, Erling; Styrvold, Olaf B

2002-05-01

233

Mon. Not. R. Astron. Soc. (2012) doi:10.1111/j.1745-3933.2012.01330.x Can R Coronae Borealis stars form from the merger of two helium  

E-print Network

Mon. Not. R. Astron. Soc. (2012) doi:10.1111/j.1745-3933.2012.01330.x Can R Coronae Borealis stars agreement with the observed abundances of R Coronae Borealis (R CrB) and extreme He stars. Such stars might for the hydrogen-deficient R Coronae Borealis (R CrB) variables (Paczy´nski 1971; Weiss 1987). R CrB stars

234

[Detection of allergenic substances (shrimp, crab) in processed seafood].  

PubMed

We have carried out a study (2009-2012) on processed seafood products in order to determine the level of contamination with shrimp and crab. In 2010-2012, after the Allergy Labeling Regulation went into effect, the detection rate of crustacean protein in processed seafood products including small fish, such as niboshi, tukudani and so on (both boiled and dried), was 63%. Detection rates for processed seafood products in which crustacean protein levels were below 1 ?g/g were 36% with and 58% without advisory labels, allowing us to conclude that 60% of labels were adequate. On the other hand, the detection rate for processed seafood products with crustacean protein levels higher than the baseline of 10 ?g/g was 9%, of which 60% carried no advisory labels. The rate of shrimp DNA detection using the Akiami primer in processed foods containing shrimp and crab was high (73%). This suggests that it is necessary to test these products using the Akiami primer for supplemental analyses of shrimp DNA. The PCR analysis for crab DNA detection failed due to combined detection of mantis shrimp DNA, which accounted for 8% of the total detected. PMID:24598226

Watanabe, Hiroko; Saita, Kiyotaka; Akaboshi, Chie; Ohsawa, Nobuhiko; Hashiguchi, Shigeki; Miyazawa, Maki

2014-01-01

235

Immunological-based assays for specific detection of shrimp viruses  

PubMed Central

Among shrimp viral pathogens, white spot syndrome virus (WSSV) and yellow head virus (YHV) are the most lethal agents, causing serious problems for both the whiteleg shrimp, Penaeus (Litopenaeus) vannamei, and the black tiger shrimp, Penaeus (Penaeus) monodon. Another important virus that infects P. vannamei is infectious myonecrosis virus (IMNV), which induces the white discoloration of affected muscle. In the cases of taura syndrome virus and Penaeus stylirostris densovirus (PstDNV; formerly known as infectious hypodermal and hematopoietic necrosis virus), their impacts were greatly diminished after the introduction of tolerant stocks of P. vannamei. Less important viruses are Penaeus monodon densovirus (PmDNV; formerly called hepatopancreatic parvovirus), and Penaeus monodon nucleopolyhedrovirus (PemoNPV; previously called monodon baculovirus). For freshwater prawn, Macrobrachium rosenbergii nodavirus and extra small virus are considered important viral pathogens. Monoclonal antibodies (MAbs) specific to the shrimp viruses described above have been generated and used as an alternative tool in various immunoassays such as enzyme-linked immunosorbent assay, dot blotting, Western blotting and immunohistochemistry. Some of these MAbs were further developed into immunochromatographic strip tests for the detection of WSSV, YHV, IMNV and PemoNPV and into a dual strip test for the simultaneous detection of WSSV/YHV. The strip test has the advantages of speed, as the result can be obtained within 15 min, and simplicity, as laboratory equipment and specialized skills are not required. Therefore, strip tests can be used by shrimp farmers for the pond-side monitoring of viral infection. PMID:24567913

Chaivisuthangkura, Parin; Longyant, Siwaporn; Sithigorngul, Paisarn

2014-01-01

236

Immunological-based assays for specific detection of shrimp viruses.  

PubMed

Among shrimp viral pathogens, white spot syndrome virus (WSSV) and yellow head virus (YHV) are the most lethal agents, causing serious problems for both the whiteleg shrimp, Penaeus (Litopenaeus) vannamei, and the black tiger shrimp, Penaeus (Penaeus) monodon. Another important virus that infects P. vannamei is infectious myonecrosis virus (IMNV), which induces the white discoloration of affected muscle. In the cases of taura syndrome virus and Penaeus stylirostris densovirus (PstDNV; formerly known as infectious hypodermal and hematopoietic necrosis virus), their impacts were greatly diminished after the introduction of tolerant stocks of P. vannamei. Less important viruses are Penaeus monodon densovirus (PmDNV; formerly called hepatopancreatic parvovirus), and Penaeus monodon nucleopolyhedrovirus (PemoNPV; previously called monodon baculovirus). For freshwater prawn, Macrobrachium rosenbergii nodavirus and extra small virus are considered important viral pathogens. Monoclonal antibodies (MAbs) specific to the shrimp viruses described above have been generated and used as an alternative tool in various immunoassays such as enzyme-linked immunosorbent assay, dot blotting, Western blotting and immunohistochemistry. Some of these MAbs were further developed into immunochromatographic strip tests for the detection of WSSV, YHV, IMNV and PemoNPV and into a dual strip test for the simultaneous detection of WSSV/YHV. The strip test has the advantages of speed, as the result can be obtained within 15 min, and simplicity, as laboratory equipment and specialized skills are not required. Therefore, strip tests can be used by shrimp farmers for the pond-side monitoring of viral infection. PMID:24567913

Chaivisuthangkura, Parin; Longyant, Siwaporn; Sithigorngul, Paisarn

2014-02-12

237

Emerging viral diseases of fish and shrimp  

USGS Publications Warehouse

The rise of aquaculture has been one of the most profound changes in global food production of the past 100 years. Driven by population growth, rising demand for seafood and a levelling of production from capture fisheries, the practice of farming aquatic animals has expanded rapidly to become a major global industry. Aquaculture is now integral to the economies of many countries. It has provided employment and been a major driver of socio-economic development in poor rural and coastal communities, particularly in Asia, and has relieved pressure on the sustainability of the natural harvest from our rivers, lakes and oceans. However, the rapid growth of aquaculture has also been the source of anthropogenic change on a massive scale. Aquatic animals have been displaced from their natural environment, cultured in high density, exposed to environmental stress, provided artificial or unnatural feeds, and a prolific global trade has developed in both live aquatic animals and their products. At the same time, over-exploitation of fisheries and anthropogenic stress on aquatic ecosystems has placed pressure on wild fish populations. Not surprisingly, the consequence has been the emergence and spread of an increasing array of new diseases. This review examines the rise and characteristics of aquaculture, the major viral pathogens of fish and shrimp and their impacts, and the particular characteristics of disease emergence in an aquatic, rather than terrestrial, context. It also considers the potential for future disease emergence in aquatic animals as aquaculture continues to expand and faces the challenges presented by climate change.

Winton, James R.; Walker, Peter J.

2010-01-01

238

Nutritional Contribution of Phytoplankton to the Pacific White Shrimp Litopenaeus vannamei  

E-print Network

. In 2009, shrimp aquaculture yields were estimated at 3.1 million metric tons (MMT) with total farmed shrimp landings valued at US$ 12.9 billion (FAO 2011). Until 2001, black tiger shrimp, Penaeus monodon, was the main species cultured comprising 70... to begin culturing the Pacific white shrimp, Litopenaeus vannamei. In 2003, the production of L. vannamei exceeded black tiger shrimp by 309,172 MT (59% of world production - FAO 2011) and it is projected that for 2013, this species will represent about...

Sanchez Corrales, Dagoberto Raul

2012-07-16

239

Summary of studies on closed-polyculture of penaeid shrimp with fishes and moluscans  

NASA Astrophysics Data System (ADS)

Closed-polyculture of Chinese penaeid shrimp, Taiwan red tilapia, and molluscans(constricted tagelus and bay scallop) was studied from 1995 to 1997 with the enclosure-experiment method, on a shrimp farm in Haiyang County, Shandong Province. Four structure-optimized closed-polyculture systems, i. e., the “shrimp-tagelus” system, the “shrimp-scallop” system, the “shrimp-tilapia” system and the “shrimp-tilapia-tagelus” system, were worked out. All these polyculture systems were superior to shrimp monoculture system in economic and ecological efficiencies. The order of these polyculture systems in efficiencies was “shrimptilapia-tagelus” > “shrimp-tagelus”>“shrimp-tilapia”>“shrimp-scallop”. The “shrimp-tilapia-tagelus” system raised the production by 28% and the utilization efficiency of input nitrogen by 85%. These closed-polyculture systems reduced the nitrogen discharge ratio to 6% 8%, instead of 40% 90% in the usual open culture systems. The ecological features of the systems were also investigated and many meaningful results have been obtained. The mechanism enhancing the efficiencies of these systems, the ways to enhance the efficiencies further and those to reuse the sedimented materials are disscussed.

Li, De-Shang; Dong, Shuang-Lin

2000-03-01

240

Cost and returns budgets for penaeid shrimp culture operations  

E-print Network

the method of Primavera (1978). Maturation animals are fed a diet of fresh frozen squid (~Loli o ~s . ), fresh frozen juvenile shrimp (Penaeus ~s . ), and fresh frozen bloodworms (Glycera dibranchiata) in a 2:1:1 ratio. Production per tank 21 td bit b P... for each piece of equipment. The maturation ration for broodstock consists of squid, juven- ile shrimp, and bloodworms and have per kilogram prices of $1. 65, $2. 75, and $22. 00, respectively. Squid are fed twice a day at ap- proximately 150g per...

Johns, M. A.

2012-06-07

241

Ex-vessel demand by size for the Gulf shrimp  

E-print Network

EX-VESSEL DEMAND BY SIZE FOR THE GULF SHRIMP A Thesis by MARGARET RAM-TOO CHUI Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1980 Major... Subject: Agricultural Economics EX-VESSEL DEMAND BY SIZE FOR SHRIMP IN THE GULF OF MEXICO A Thesis by MARGARET KAM-TOO CHUI Approved as to style and content by: ai an of Committee) (Hea f ep tment) (Member) (Member) August 1980 ABSTRACT Ex...

Chui, Margaret Kam-Too

2012-06-07

242

Discovery of Five New R Coronae Borealis Stars in the MACHO Galactic Bulge Database  

NASA Astrophysics Data System (ADS)

We have identified five new R Coronae Borealis (RCB) stars in the Galactic bulge using the MACHO Project photometry database, raising the total number of known Galactic RCB stars to about 40. We have obtained spectra to confirm the identifications. The fact that four out of the five newly identified RCB stars are ``cool'' (Teff<6000 K) rather than ``warm'' (Teff>6000 K) suggests that the preponderance of warm RCB stars among the existing sample is a selection bias. These cool RCB stars are redder and fainter than their warm counterparts and may have been missed in surveys done with blue plates. Based on the number of new RCB stars discovered in the MACHO bulge fields, there may be ~250 RCB stars in the reddened ``exclusion'' zone toward the bulge.

Zaniewski, A.; Clayton, Geoffrey C.; Welch, D. L.; Gordon, Karl D.; Minniti, D.; Cook, K. H.

2005-11-01

243

Discovery of Five New R. Coronae Borealis Stars in the MACHO Galactic Bulge Database  

SciTech Connect

We have identified five new R Coronae Borealis (RCB) stars in the Galactic bulge using the MACHO Project photometry database, raising the total number of known Galactic RCB stars to about 40. We have obtained spectra to confirm the identifications. The fact that four out of the five newly identified RCB stars are ''cool'' (T{sub eff} < 6000 K) rather than ''warm'' (T{sub eff} > 6000 K) suggests that the preponderance of warm RCB stars among the existing sample is a selection bias. These cool RCB stars are redder and fainter than their warm counterparts and may have been missed in surveys done with blue plates. Based on the number of new RCB stars discovered in the MACHO bulge fields, there may be {approx}250 RCB stars in the reddened ''exclusion'' zone toward the bulge.

Zaniewshi, A; Clayton, G C; Welch, D; Gordon, K D; Minniti, D; Cook, K

2005-06-16

244

The origin of the cold spot in the Corona Borealis supercluster  

NASA Astrophysics Data System (ADS)

The Very Small Array (VSA) detected a cold spot in the Cosmic Microwave Background (CMB) towardsthe Corona Borealis supercluster of galaxies. The origin of this spot remains unclear as itis not obviously associated to any known cluster of galaxies. We present here recent observationalresults (GTC, WHT, SDSS) and theoretical (N-body simulations) studies aimed to better understandthe origin of this anomalous spot.We carried out a near-IR survey (LIRIS@WHT) complemented with optical data (ACAM@WHT, OSIRIS@GTC and SDSS) in the line of sight of the core of this supercluster to search for new clusters of galaxies at a higher redshift. Using the Mare Nostrum Universe (an N-body SPH cosmological simulationby Yepes et al. 2007), we also study the potential of the different physical phases insuperclusters to produce similar thermal Sunyaev-Zeldovich signals to the observed in the cold spot.

Flores-Cacho, I.; Rubiño-Martín, J. A.; Rebolo, R.

2011-11-01

245

Nucleosynthesis during the Merger of White Dwarfs and the Origin of R Coronae Borealis Stars  

E-print Network

Many hydrogen deficient stars are characterised by surface abundance patterns that are hard to reconcile with conventional stellar evolution. Instead, it has been suggested that they may represent the result of a merger episode between a helium and a carbon-oxygen white dwarf. In this Letter, we present a nucleosynthesis study of the merger of a 0.4 M_sol helium white dwarf with a 0.8 M_sol carbon-oxygen white dwarf, by coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars.

Longland, R; José, J; García-Berro, E; Althaus, L G; Isern, J

2011-01-01

246

Photometric analysis of Magellanic Cloud R Coronae Borealis Stars in the recovery phase of their declines  

E-print Network

This paper presents the initial results of a multi-site photometric programme to examine the extraordinary behaviour displayed by 18 R Coronae Borealis (RCB) stars in the Magellanic Clouds (MCs). RCB stars exhibit a unique variability whereby they undergo rapid declines of up to several magnitudes. These are thought to be caused by the formation of dust in the stellar environment which reduces the brightness. The monitoring programme comprised the collection of UBVRI photometric data using five telescopes located at three different southern hemisphere longitudes (Las Campanas Observatory in Chile, Mount Joun University Observatory in New Zealand, and the Southern African Large Telescope (SALT) in South Africa). Examination of the data acquired in the V and I filters resulted in the identification of a total of 18 RCB declines occurring in four stars. Construction of colour-magnitude diagrams (V vs V-I), during the recovery to maximum light were undertaken in order to study the unique colour behaviour associat...

Woollands, Robyn M; Udalski, A

2009-01-01

247

EROS 2 photometry of probable R Coronae Borealis stars in the Small Magellanic Cloud  

E-print Network

EROS 2 (Experience de Recherche d'Objets Sombres) conducted a survey of the SMC between July 1996 and February 2003 in two EROS broad-band colours, V_E and R_E. The photometric data of 4.2 million stars have been searched for behaviour typical of R Coronae Borealis (RCB) candidates such as drastic changes in magnitude. Five objects have been found, four of them being catalogued in the Simbad database as RAW 21, RAW 233, RAW 476, and [MH95] 431 with confirmed carbon-rich atmospheres, characteristic of RCB. From the EROS 2 light curve of RAW 21 and its spectrum reported by Morgan et al. (2003), we confirm that it is the first RCB to be found in the SMC. The other objects are new RCB candidates with absolute luminosity and colour close to those found for RCBs in the LMC. We propose that 2 of them are DY Per-like RCBs.

P. Tisserand; J. B. Marquette; J. P. Beaulieu; P. de Laverny

2004-05-27

248

Discovery of Five New R Coronae Borealis Stars in the MACHO Galactic Bulge Database  

E-print Network

We have identified five new R Coronae Borealis (RCB) stars in the Galactic bulge using the MACHO Project photometry database, raising the total number of known Galactic RCB stars to about 40. We have obtained spectra to confirm the identifications. The fact that four out of the five newly identified RCB stars are ``cool'' (T(eff) 6000 K) suggests that the preponderance of warm RCB stars among the existing sample is a selection bias. These cool RCB stars are redder and fainter than their warm counterparts and may have been missed in surveys done with blue plates. Based on the number of new RCB stars discovered in the MACHO bulge fields, there may be ~250 RCB stars in the reddened "exclusion" zone toward the bulge.

Zaniewski, A; Welch, D L; Gordon, K D; Minniti, D; Cook, K H; Clayton, Geoffrey C.; Gordon, Karl D.

2005-01-01

249

Surface Compositions of R Coronae Borealis Stars and Extreme Helium Stars - Some Connections  

E-print Network

Abundances of R Coronae Borealis stars (RCBs) and Extreme Helium stars (EHes) are discussed. Recent estimates of the $s$-process elements in hot extreme helium stars show enhancements of lighter $s$-process elements (Y, Zr) relative to heavier $s$-process elements, a characteristic shared by RCB stars. It also suggests that atleast some EHe stars went through an episode of $s$-process element synthesis in their earlier evolution. A majority of RCB stars show a high $^{12}$C/$^{13}$C ratio in their atmospheres. A recent analysis of the spectrum of minority RCB star V CrA, however, shows a lower value between 4 $-$ 10. The implications of these results are discussed.

N. Kameswara Rao

2004-10-27

250

Nucleosynthesis during the Merger of White Dwarfs and the Origin of R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

Many hydrogen-deficient stars are characterized by surface abundance patterns that are hard to reconcile with conventional stellar evolution. Instead, it has been suggested that they may represent the result of a merger episode between a helium and a carbon-oxygen white dwarf. In this Letter, we present a nucleosynthesis study of the merger of a 0.4 M sun helium white dwarf with a 0.8 M sun carbon-oxygen white dwarf, by coupling the thermodynamic history of Smoothed Particle Hydrodynamics particles with a post-processing code. The resulting chemical abundance pattern, particularly for oxygen and fluorine, is in qualitative agreement with the observed abundances in R Coronae Borealis stars.

Longland, R.; Lorén-Aguilar, P.; José, J.; García-Berro, E.; Althaus, L. G.; Isern, J.

2011-08-01

251

Discovery of Five New R Coronae Borealis Stars in the MACHO Galactic Bulge Database  

E-print Network

We have identified five new R Coronae Borealis (RCB) stars in the Galactic bulge using the MACHO Project photometry database, raising the total number of known Galactic RCB stars to about 40. We have obtained spectra to confirm the identifications. The fact that four out of the five newly identified RCB stars are ``cool'' (T(eff) 6000 K) suggests that the preponderance of warm RCB stars among the existing sample is a selection bias. These cool RCB stars are redder and fainter than their warm counterparts and may have been missed in surveys done with blue plates. Based on the number of new RCB stars discovered in the MACHO bulge fields, there may be ~250 RCB stars in the reddened "exclusion" zone toward the bulge.

A. Zaniewski; Geoffrey C. Clayton; D. L. Welch; Karl D. Gordon; D. Minniti; K. H. Cook

2005-09-21

252

What is the True Population of the R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

The R Coronae Borealis (RCB) stars are rare hydrogen-deficient, carbon-rich supergiants. Two evolutionary scenarios have been suggested, a double degenerate merger of two white dwarfs (WDs), or a final helium shell flash (FF) in a PN central star. The evidence pointing toward a WD merger or a FF origin for RCB stars is contradictory. Therefore, determining the population of RCB stars is very important. Predictions of the number of RCB stars in the Galaxy range as high as 5,000 but very few RCB stars are known. The discovery rate for RCB stars has been accelerated by the use of WISE IR colors and the ASAS-3 lightcurves. The number of Milky Way RCB stars identified has doubled in just a few years to about 100 and may double again soon.

Clayton, G.

2014-04-01

253

The changing nebula around the hot R Coronae Borealis star DY Centauri  

NASA Astrophysics Data System (ADS)

Among the distinguishing characteristics of the remarkable hot R Coronae Borealis star DY Centauri, which was recently found to be a spectroscopic binary, is the presence of nebular forbidden lines in its optical spectrum. A compilation of photometry from 1970 to the present suggests that the star has evolved to higher effective temperatures. A comparison of spectra from 2010 with earlier spectra has shown that between 2003 and 2010, the 6717 and 6730 Å emission lines of [S II] underwent a dramatic change in their fluxes. This suggests that there was an increase in the nebula's electron density from 290 to 3140 cm-3 between 1989 and 2010, while the stellar temperature increased from 19 500 to 25 000 K. The nebular radius is about 0.02 pc, which is 60 000 times larger than the semimajor axis of the DY Cen binary system. The rapid changes of stellar temperature and the nebula's response to these changes demonstrate stellar evolution in action.

Kameswara Rao, N.; Lambert, David L.; García-Hernández, D. A.; Manchado, Arturo

2013-05-01

254

Are C60 molecules detectable in circumstellar shells of R Coronae Borealis stars?  

E-print Network

The hydrogen-poor, helium-rich and carbon-rich character of the gas around R Coronae Borealis (RCB) stars has been suggested to be a site for formation of C60 molecules. This suggestion is not supported by observations reported here showing that infrared transitions of C60 are not seen in a large sample of RCB stars observed with the Infrared Spectrograph on the Spitzer Space Telescope. The infrared C60 transitions are seen, however, in emission and blended with PAH-features in spectra of DY Cen and possibly also of V854 Cen, the two least hydrogen-deficient (hydrogen deficiency of only ~10-100) RCB stars. The speculation is offered that C60 (and the PAHs) in the moderately H-deficient circumstellar envelopes may be formed by the decomposition of hydrogenated amorphous carbon but fullerene formation is inefficient in the highly H-deficient environments of most RCBs.

Garcia-Hernandez, D A; Lambert, D L

2011-01-01

255

Millimetric observation of the SZ effect in the Corona Borealis supercluster  

E-print Network

We have observed the Corona Borealis Supercluster with the Millimeter and Infrared Testa grigia Observatory (MITO), located in the Italian Alps, at 143, 214, 272, and 353 GHz. We present a description of the measurements, data analysis, and results of the observations together with a comparison with observations performed at 33 GHz with the Very Small Array (VSA) interferometer situated at the Teide Observatory (Tenerife-Spain). Observations have been made in the direction of the supercluster towards one Cosmic Microwave Background (CMB) cold spot previously detected in a VSA temperature map. Observational strategy and data analysis are described in detail, explaining the procedures used to disentangle primary and secondary anisotropies in the resulting maps. From a first level of data analysis we find evidence in MITO data of primary anisotropy, however still with room for the presence of secondary anisotropy, especially when VSA results are included. With a second level of data analysis using map-making and...

Battistelli, E S; Davis, R J; De Gregori, S; Genova-Santos, R; Grainge, K; Hobson, M P; Lamagna, L; Luzzi, G; Melchiorri, F; Petris, M D; Rebolo, R; Rubi~no-Martin, J A; Saunders, R D E; Scott, P F; Watson, R A

2006-01-01

256

The changing nebula around the hot R Coronae Borealis star DY Centauri  

E-print Network

Among the distinguishing characteristics of the remarkable hot R Coronae Borealis star DY Cen, which was recently found to be a spectroscopic binary, is the presence of nebular forbidden lines in its optical spectrum. A compilation of photometry from 1970 to the present suggests that the star has evolved to higher effective temperatures. Comparison of spectra from 2010 with earlier spectra show that between 2003 and 2010, the 6717 and 6730 A emission lines of [S II] underwent a dramatic change in their fluxes suggesting an increase in the nebula's electron density of 290 cm-3 to 3140 cm-3 from 1989 to 2010 while the stellar temperature increased from 19500 K to 25000 K. The nebular radius is about 0.02 pc, 60000 times bigger than the semimajor axis of DY Cen binary system. Rapid changes of stellar temperature and its response by the nebula demonstrate stellar evolution in action.

Rao, N Kameswara; Garcia-Hernandez, D A; Manchado, A

2013-01-01

257

Low-frequency vocalizations of sei whales (Balaenoptera borealis) in the Southern Ocean.  

PubMed

Simultaneous sightings and acoustic detections of sei whales (Balaenoptera borealis) are scarce, and there are few published data describing their vocalizations. Analysis of recordings from directional frequency analysis and recording sonobuoys in the presence of sei whales in the Southern Ocean in March 2013 identified both downsweep and upsweep calls. Sound frequencies within all calls were between 34 and 87?Hz with an average call duration of 1.1?s. These very low-frequency sounds share characteristics with sei whale calls recorded near the Hawaiian Islands and off Cape Cod in winter and summer, respectively, but are the first documented sei whale calls in the Southern Ocean that are clearly less than 100?Hz. PMID:25480092

Calderan, Susannah; Miller, Brian; Collins, Kym; Ensor, Paul; Double, Michael; Leaper, Russell; Barlow, Jay

2014-12-01

258

Caryospora uptoni n. sp. (Apicomplexa: Eimeriidae) from red-tailed hawks (Buteo jamaicensis borealis).  

PubMed

Oocysts of Caryospora uptoni n. sp. were described from the feces of red-tailed hawks, Buteo jamaicensis borealis. Sporulated oocysts were spherical or subspherical and measured 28.1 by 26.4 micron. The oocyst wall was composed of a yellowish outer layer and brownish inner layer and was about 1.5 micron thick. Neither micropyle, polar granules, nor oocyst residuum were present. A single, spherical sporocyst 18.2 by 17.9 micron was present; a Stieda body was absent. A spherical eccentrically located sporocyst residuum was present in many sporocysts, but it degenerated to form a dispersed granular residuum in other sporocysts. Eight randomly arranged sporozoites, 12.6 by 4.2 micron, were present in each sporocyst; they contained a centrally or slightly posteriorly located nucleus. PMID:3806324

Lindsay, D S; Blagburn, B L

1986-10-01

259

The Norris Survey of the Corona Borealis Supercluster: II. Galaxy Evolution with Redshift and Environment  

E-print Network

We measure the field galaxy luminosity function (LF) as a function of color and redshift from z = 0 to z = 0.5 using galaxies from the Norris Survey of the Corona Borealis Supercluster. We find that our local r-band LF, when normalized to counts in high galactic latitude fields, agrees well with the local LF measured in the Las Campanas Redshift Survey. Our B-band local LF, however, does not match the B-band LF from the Stromlo/APM survey, having a normalization 1.6 times higher. We see compelling evidence that B-band field galaxy LF evolves with redshift. The evolution is strongest for the population of star-forming galaxies with [OII]3727 rest-frame equivalent widths greater than 10A. The population of red, quiescent galaxies shows no sign of evolution to z = 0.5. The evolution of the LF which we observe is consistent with the findings of other faint galaxy redshift surveys. The fraction of galaxies with [OII] emission increases rapidly with redshift, but the fraction of galaxies with strong Hdelta 4101 absorption, a signature of a burst of star formation, does not. We thus conclude that the star formation in distant galaxies is primarily long-lived. We also compute the LFs of the Corona Borealis supercluster and the A2069 supercluster. The shapes of the two supercluster LFs are broadly similar to the shape of the local LF. However, there are important differences. Both supercluster LFs have an excess of very bright galaxies. In addition, there is a suggestion of an upturn in the LF for galaxies fainter than M(B) = -17 mag. (Abridged from the abstract in the paper.)

Todd A. Small; Wallace L. W. Sargent; Donald Hamilton

1997-05-05

260

Phylogeny and evolution of Indo-Pacific shrimp-associated gobies (Gobiiformes: Gobiidae).  

PubMed

Despite the ubiquity of obligate mutualisms on coral reef ecosystems, little is known about the evolution of many participating species. The shrimp gobies, known primarily from the coral reef habitats of the Indo-Pacific, are small benthic fishes that participate in a remarkable mutualism with alpheid shrimp. In this mutualism, the shrimp build and maintain a burrow that is guarded by the goby, and the shrimp and goby engage in an intricate tactile communication system. The mutualism is obligate for most shrimp gobies as participating species are highly vulnerable to predation when separated from a shrimp partner. We use phylogenetic analysis of nuclear and mitochondrial DNA sequence data to infer evolutionary relationships among shrimp gobies, and between shrimp gobies and their non-mutualistic gobiid relatives. We show that the mutualist shrimp association has arisen twice among gobies, once in a clade composed of Amblyeleotris, Ctenogobiops, and Vanderhorstia, and a second time in a clade including Cryptocentrus, Mahidolia, Tomiamichthys and Stonogobiops. We then compare the evolution of traits within each shrimp goby clade and consider their intrarelationships. We document cryptic diversity among shrimp gobies, with three distinct clades delineated among Mahidolia mysticina specimens captured at the same locality, paired with the same shrimp species. Mahidolia is placed as sister to the Cryptocentrus species Cryptocentrus cinctus; both exhibit pronounced dichromatism, occurring in both brown and yellow (xanthic) forms. We additionally clarify species identities within Amblyeleotris, confirming that widespread similar species Amblyeleotris fasciata, Amblyeleotris steinitzi and Amblyeleotris wheeleri are all distinct. We hypothesize that the flexibility of gobiid gobies and alpheid shrimp to interact with mutualist partners, as well as the apparently highly beneficial nature of mutualism between them, has contributed to the dual evolution of shrimp-association among Indo-Pacific gobies. PMID:21315161

Thacker, Christine E; Thompson, Andrew R; Roje, Dawn M

2011-04-01

261

Discovery of a Previously Unrecognised Allusion to the Aurora Borealis in Paradise Lost, and Implications for Edmund Halley Scholarship  

NASA Astrophysics Data System (ADS)

This research reveals that John Milton employed an allusion to the aurora borealis in the epic poem Paradise Lost which has not been recognised in more than three centuries of scholarly analysis. It further disproves the long-held belief, made popular by the astronomer Edmund Halley, that no notable aurora was visible in England in the seventeenth century. A study of the personal Latin diary of the Elizabethan historian William Camden shows that the famous aurora of 1621 was visible in England. While Pierre Gassendi has been credited with creation of the term 'aurora borealis' based on his report of the 1621 aurora, this study reaffirms a neglected analysis from 1986 that established the term originated with Galileo in 1619.

Cunningham, Clifford J.

2014-11-01

262

Emerging viral diseases of fish and shrimp.  

PubMed

The rise of aquaculture has been one of the most profound changes in global food production of the past 100 years. Driven by population growth, rising demand for seafood and a levelling of production from capture fisheries, the practice of farming aquatic animals has expanded rapidly to become a major global industry. Aquaculture is now integral to the economies of many countries. It has provided employment and been a major driver of socio-economic development in poor rural and coastal communities, particularly in Asia, and has relieved pressure on the sustainability of the natural harvest from our rivers, lakes and oceans. However, the rapid growth of aquaculture has also been the source of anthropogenic change on a massive scale. Aquatic animals have been displaced from their natural environment, cultured in high density, exposed to environmental stress, provided artificial or unnatural feeds, and a prolific global trade has developed in both live aquatic animals and their products. At the same time, over-exploitation of fisheries and anthropogenic stress on aquatic ecosystems has placed pressure on wild fish populations. Not surprisingly, the consequence has been the emergence and spread of an increasing array of new diseases. This review examines the rise and characteristics of aquaculture, the major viral pathogens of fish and shrimp and their impacts, and the particular characteristics of disease emergence in an aquatic, rather than terrestrial, context. It also considers the potential for future disease emergence in aquatic animals as aquaculture continues to expand and faces the challenges presented by climate change. PMID:20409453

Walker, Peter J; Winton, James R

2010-01-01

263

Emerging viral diseases of fish and shrimp  

PubMed Central

The rise of aquaculture has been one of the most profound changes in global food production of the past 100 years. Driven by population growth, rising demand for seafood and a levelling of production from capture fisheries, the practice of farming aquatic animals has expanded rapidly to become a major global industry. Aquaculture is now integral to the economies of many countries. It has provided employment and been a major driver of socio-economic development in poor rural and coastal communities, particularly in Asia, and has relieved pressure on the sustainability of the natural harvest from our rivers, lakes and oceans. However, the rapid growth of aquaculture has also been the source of anthropogenic change on a massive scale. Aquatic animals have been displaced from their natural environment, cultured in high density, exposed to environmental stress, provided artificial or unnatural feeds, and a prolific global trade has developed in both live aquatic animals and their products. At the same time, over-exploitation of fisheries and anthropogenic stress on aquatic ecosystems has placed pressure on wild fish populations. Not surprisingly, the consequence has been the emergence and spread of an increasing array of new diseases. This review examines the rise and characteristics of aquaculture, the major viral pathogens of fish and shrimp and their impacts, and the particular characteristics of disease emergence in an aquatic, rather than terrestrial, context. It also considers the potential for future disease emergence in aquatic animals as aquaculture continues to expand and faces the challenges presented by climate change. PMID:20409453

Walker, Peter J.; Winton, James R.

2010-01-01

264

A Very Small Array search for the extended Sunyaev-Zel'dovich effect in the Corona Borealis supercluster  

Microsoft Academic Search

We present interferometric imaging at 33 GHz of the Corona Borealis supercluster, using the extended configuration of the Very Small Array. A total area of 24 deg2 has been imaged, with an angular resolution of 11 arcmin and a sensitivity of 12 mJy beam-1. The aim of these observations is to search for Sunyaev-Zel'dovich (SZ) detections from known clusters of

Ricardo Génova-Santos; José Alberto Rubiño-Martín; Rafael Rebolo; Kieran Cleary; Rod D. Davies; Richard J. Davis; Clive Dickinson; Nelson Falcón; Keith Grainge; Carlos M. Gutiérrez; Michael P. Hobson; Michael E. Jones; Rüdiger Kneissl; Katy Lancaster; Carmen P. Padilla-Torres; Richard D. E. Saunders; Paul F. Scott; Angela C. Taylor; Robert A. Watson

2005-01-01

265

BeppoSAX temperature maps of galaxy clusters in the Corona Borealis supercluster: A2061, A2067 and A2124  

Microsoft Academic Search

In this paper we present the analysis of BeppoSAX observations of the cluster pairs A2061-A2067 and A2122-A2124, located in the Corona Borealis supercluster, which have been selected as candidate merging clusters. The aim of this work is to study the physics of the intracluster medium and to look for the possible presence of merging signatures. We derived the global temperatures

F. Marini; S. Bardelli; E. Zucca; S. De Grandi; A. Cappi; S. Ettori; L. Moscardini; G. Tormen; A. Diaferio

2004-01-01

266

Three-dimensional Doppler Tomogram of Gas Flows in the Algol-Type Binary U Coronae Borealis  

Microsoft Academic Search

The reconstruction of three-dimensional (3D) Doppler tomograms based on observational data has been accomplished for the first time. The distribution of the Halpha emission intensity I(Vx,Vy,Vz) of the interacting Algol binary system U Coronae Borealis has been restored in 3D velocity space with resolutions of 30 km s-1 in Vx and Vy and 110 km s-1 in Vz. The reconstruction

Michail Agafonov; Mercedes Richards; Olga Sharova

2006-01-01

267

Biokinetics of plutonium, americium and californium in the marine isopod Cirolana borealis , with observations on its feeding and molting behavior  

Microsoft Academic Search

In a series of laboratory experiments carried out during 1982, the biokinetics of 237Pu (IV), 237Pu (V), 241Am (III), and 252Cf (III) were studied in the benthic marine isopod Cirolana borealis Lilljeb. Following a 3 wk exposure to labelled seawater, isopods reached non-equilibrium concentration factors of 52±15, 54±12, 176±14, and 185±53 for Pu (IV), Pu (V), Am and Cf, respectively.

F. P. Carvalho; S. W. Fowler

1985-01-01

268

Stable isotope analysis of some representative fish and invertebrates of the Newfoundland and Labrador continental shelf food web  

NASA Astrophysics Data System (ADS)

We examined stable carbon and nitrogen isotopic signatures of 17 fish and 16 invertebrate taxa common to the Newfoundland and Labrador (NL) continental shelf food web. Particular sampling emphasis was placed on Atlantic cod ( Gadus morhua) and related prey species (e.g. shrimp, Pandalus borealis, and capelin, Mallotus villosus). We found highly significant ( p < 0.0001) differences between near-shore (bays) and offshore (shelf edge) ?15N signatures for cod, 'other fish' (pooled) and invertebrates (pooled). In contrast, there were only minor differences in ?13C signatures of 'other fish' ( p < 0.05) and no difference for cod and invertebrates among the two habitats. We sampled at two times of the year (January and June) and found no systematic effect of season on both ?13C and ?15N in cod, 'other fish' and invertebrates. We calculated isotopic fractionation factors for cod from the entire shelf (mixed diet) and for cod with diets composed mainly of capelin or shrimp. These values ranged between 2.2‰ and 3.9‰ for ?15N and -0.4‰ and 0.8‰ for ?13C and, for ?15N, may reflect diet-related differences in bioenergetic status. We discuss potential mechanisms for near-shore versus offshore enrichment of ?15N signatures, and demonstrate the implications of this spatial variation on ?15N-derived trophic position estimates.

Sherwood, Graham D.; Rose, George A.

2005-06-01

269

The effect of Echinorhynchus borealis (Acanthocephala) infection on the anti-predator behavior of a benthic amphipod.  

PubMed

In benthic habitats, predators can generally not be detected visually, so olfaction may be particularly important for inducing anti-predation behaviors in prey organisms. Manipulative parasites infecting benthic hosts could suppress these responses so as to increase the probability of predation and thus trophic transmission. We studied how infection with the acanthocephalan Echinorhynchus borealis affects the response of the benthic amphipod Pallasea quadrispinosa to water conditioned by burbot (Lota lota), the parasite's definitive host. In normal lake water, refuge use by infected and uninfected amphipods was similar, but when exposed to burbot-conditioned water, uninfected amphipods spent much more time hiding than infected amphipods. Thus, rather than affecting ambient hiding behavior, E. borealis infection seems to alter host response to a predator. A group of amphipods sampled from a postglacial spring that is devoid of fish predators exhibited only a weak response to burbot-conditioned water, perhaps suggesting these anti-predator behaviors are costly to maintain. The hiding behavior of spring and infected amphipods was very similar. If the reduced refuge use by the spring amphipods reflects adaptation to a predator-free environment, this indicates that E. borealis severely weakens its host's anti-predator behavior. Presumably this increases the likelihood of parasite transmission. PMID:18564759

Benesh, D P; Kitchen, J; Pulkkinen, K; Hakala, I; Valtonen, E T

2008-04-01

270

Recent population expansion and connectivity in the hydrothermal shrimp  

E-print Network

-sea hydrothermal vents are unstable habitats that are both spatially and temporally fragmented. In vent species of the shrimp Rimicaris exoculata, which forms high-density local populations on hydrothermal vents along the Mid-Atlantic ridge. Location Deep-sea hydrothermal vents along the Mid-Atlantic Ridge. Methods We used

Teixeira, Sara

271

Talking about Brine Shrimps: Three Ways of Analysing Pupil Conversations.  

ERIC Educational Resources Information Center

Applies three distinct analyses to recorded and transcribed student conversations (n=240) about brine shrimps. The complementary analytic methods provide information on the content of pupils' conversations in terms of the observations made, the ways in which pupils make sense of their observations, and the ways in which students use conversation…

Tunnicliffe, Sue Dale; Reiss, Michael J.

1999-01-01

272

The Freshwater Shrimps Of Curaçao, West Indies (decapoda, Caridea)  

Microsoft Academic Search

On the basis of a é eld survey and review of existing records I here report on the occurrence of ten freshwater shrimp species in Curaç ao. Four species constitute new and\\/or previously unpublished records for the island. Existing records for the neighbouring islands of Bonaire and Aruba are reviewed. The most common species are Macrobrachium carcinus , M. crenulatum,

Adolphe O. Debrot

2003-01-01

273

CO2 Efflux from Shrimp Ponds in Indonesia  

PubMed Central

The conversion of mangrove forest to aquaculture ponds has been increasing in recent decades. One of major concerns of this habitat loss is the release of stored ‘blue’ carbon from mangrove soils to the atmosphere. In this study, we assessed carbon dioxide (CO2) efflux from soil in intensive shrimp ponds in Bali, Indonesia. We measured CO2 efflux from the floors and walls of shrimp ponds. Rates of CO2 efflux within shrimp ponds were 4.37 kg CO2 m?2 y?1 from the walls and 1.60 kg CO2 m?2 y?1 from the floors. Combining our findings with published data of aquaculture land use in Indonesia, we estimated that shrimp ponds in this region result in CO2 emissions to the atmosphere between 5.76 and 13.95 Tg y?1. The results indicate that conversion of mangrove forests to aquaculture ponds contributes to greenhouse gas emissions that are comparable to peat forest conversion to other land uses in Indonesia. Higher magnitudes of CO2 emission may be released to atmosphere where ponds are constructed in newly cleared mangrove forests. This study indicates the need for incentives that can meet the target of aquaculture industry without expanding the converted mangrove areas, which will lead to increased CO2 released to atmosphere. PMID:23755306

Sidik, Frida; Lovelock, Catherine E.

2013-01-01

274

Diel and Seasonal Occurrence of Pink Shrimp, Penaeus duorarum  

E-print Network

of Tampa Bay, Florida SPECIAL SCIENTIFIC REPORT-FISHERIES Na 561 UNI ITATES DEPARTMEJfMOF^J>}^ FISH Habitats of Tampa Bay, Florida By CARL H. SALOMAN Contribution No. 37, Bureau of Commercial Fisheries Shrimp, Penaeus duorarum Burkenroad, in Two Divergent Habitats of Tampa Bay, Florida By CARL H. SALOMAN

275

The Lobster and Shrimp Fisheries in Hawaii The Lobster Fishery  

E-print Network

The Lobster and Shrimp Fisheries in Hawaii The Lobster Fishery Introduction The commercial lobster, and commercial trapping be gan in 1977 (Uchida and Tagami, 1984). Since 1983, the lobster fleet has ranged from 9 Center Na tional Marine Fisheries Service, NOAA, 2570 Dole Street, Honolulu, Hawaii 96822-2396. Mention

276

Bringing Scientific Inquiry Alive Using Real Grass Shrimp Research  

ERIC Educational Resources Information Center

This lesson was developed for middle school students using actual research on grass shrimp ("Palaemonetes pugio") to illustrate the process of a scientific investigation. The research was conducted at Savannah State University and funded by the National Oceanic and Atmospheric Administration (NOAA) Office of Education through the Living Marine…

Aultman, Terry; Curran, Mary Carla; Partridge, Michael

2010-01-01

277

JANUARY TO APRIL DISTRIBUTION OF THE COMMON SHRIMP ON THE  

E-print Network

. 171 Washington, D. C. April 1956 #12;M/V Pelican of the U.S. Fish and Wildlife Service ABSTRACT or brown shrimps (P . aztecus and P. duorarum) occur on the Shelf outside the present limits of the fishery. Milton J. Lindner, Edgar M. Smith, and Edgar L. Raymond, Master of the Pelican, contributed much

278

Introduction Bycatch in shrimp trawls is a signifi-  

E-print Network

Texas and southwestern Florida. Gear information, such as net characteris- tics, bycatch reduction plan in 1992 to identify, develop, and evaluate gear options to reduce bycatch in the Gulf of Mexico and South Atlan- tic shrimp fisheries (NMFS5; Hoar et al.6). More than 150 bycatch reduction device (BRD

279

Zhongshania aliphaticivorans sp. nov., an aliphatic hydrocarbon-degrading bacterium isolated from marine sediment, and transfer of Spongiibacter borealis Jang et al. 2011 to the genus Zhongshania as Zhongshania borealis comb. nov.  

PubMed

A Gram-staining-negative, facultatively aerobic bacterium, designated SM-2(T), was isolated from a sea-tidal flat of Yellow Sea, South Korea. Cells were catalase- and oxidase-positive motile rods with a single polar flagellum. Growth of strain SM-2(T) was observed at 10-37 °C (optimum, 25-30 °C), at pH 5.5-8.5 (optimum, pH 7.0-7.5) and in the presence of 0-11% (w/v) NaCl (optimum, 2%). Strain SM-2(T) contained ubiquinone-8 (Q-8) as the sole isoprenoid quinone and C(17:1)?8c, summed feature 3 (comprising C(16:1)?7c and/or iso-C(15:0) 2-OH), C(17:0) and C(18:1)?7c as the major fatty acids. Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified lipid were identified as the major cellular polar lipids. The G+C content of the genomic DNA was 52.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SM-2(T) formed a tight phyletic lineage with Zhongshania antarctica ZS5-23(T), Zhongshania guokunii ZS6-22(T) and Spongiibacter borealis CL-AS9(T), but that S. borealis CL-AS9(T) was distinct from other species of the genus Spongiibacter. Based on 16S rRNA gene sequence similarities, strain SM-2(T) was most closely related to S. borealis CL-AS9(T), Z. antarctica ZS5-23(T) and Z. guokunii ZS6-22(T), with similarities of 99.5%, 98.9% and 98.7%, respectively, but the DNA-DNA hybridization values among these species were clearly lower than 70%. On the basis of chemotaxonomic data and molecular properties, we propose strain SM-2(T) represents a novel species of the genus Zhongshania with the name Zhongshania aliphaticivorans sp. nov. (type strain SM-2(T)?=KACC 18120(T)?=JCM 30138(T)). We also propose the transfer of Spongiibacter borealis Jang et al. 2011 to the genus Zhongshania as Zhongshania borealis comb. nov. (type strain CL-AS9(T)?=KCCM 90094(T)?=JCM 17304(T)). PMID:25122615

Lo, Naysim; Kang, Hyo Jung; Jeon, Che Ok

2014-11-01

280

Microhabitat and shrimp abundance within a Norwegian cold-water coral ecosystem  

NASA Astrophysics Data System (ADS)

Cold-water coral (CWC) reefs are heterogeneous ecosystems comprising numerous microhabitats. A typical European CWC reef provides various biogenic microhabitats (within, on and surrounding colonies of coral species such as Lophelia pertusa, Paragorgia arborea and Primnoa resedaeformis, or formed by their remains after death). These microhabitats may be surrounded and intermixed with non-biogenic microhabitats (soft sediment, hard ground, gravel/pebbles, steep walls). To date, studies of distribution of sessile fauna across CWC reefs have been more numerous than those investigating mobile fauna distribution. In this study we quantified shrimp densities associated with key CWC microhabitat categories at the Røst Reef, Norway, by analysing image data collected by towed video sled in June 2007. We also investigated shrimp distribution patterns on the local scale (<40 cm) and how these may vary with microhabitat. Shrimp abundances at the Røst Reef were on average an order of magnitude greater in biogenic reef microhabitats than in non-biogenic microhabitats. Greatest shrimp densities were observed in association with live Paragorgia arborea microhabitat (43 shrimp m-2, SD = 35.5), live Primnoa resedaeformis microhabitat (41.6 shrimp m-2, SD = 26.1) and live Lophelia pertusa microhabitat (24.4 shrimp m-2, SD = 18.6). In non-biogenic microhabitat, shrimp densities were <2 shrimp m-2. CWC reef microhabitats appear to support greater shrimp densities than the surrounding non-biogenic microhabitats at the Røst Reef, at least at the time of survey.

Purser, A.; Ontrup, J.; Schoening, T.; Thomsen, L.; Tong, R.; Unnithan, V.; Nattkemper, T. W.

2013-09-01

281

Microhabitat and shrimp abundance within a Norwegian cold-water coral ecosystem  

NASA Astrophysics Data System (ADS)

Cold-water coral reefs are highly heterogeneous ecosystems comprising of a range of diverse microhabitats. In a typical European cold-water coral reef various biogenic habitats (live colonies of locally common coral species such as Lophelia pertusa, Paragorgia arborea and Primnoa resedaeformis, dead coral structure, coral rubble) may be surrounded and intermixed with non-biogenic habitats (soft sediment, hardground, gravel/pebbles, steep walls). To date, studies of distribution of sessile fauna across these microhabitats have been more numerous than those investigating mobile fauna distribution. In this study we quantified shrimp densities associated with key CWC habitat categories at the Røst reef, Norway, by analysing image data collected by towed video sled. We also investigated shrimp distribution patterns on the local scale (<40 cm) and how these may vary with habitat. We found shrimp abundances at the Røst reef to be on average an order of magnitude greater in biogenic reef habitats than in non-biogenic habitats. Greatest shrimp densities were observed in association with live Paragorgia arborea habitats (43 shrimp m-2, SD = 35.5), live Primnoa resedaeformis habitats (41.6 shrimp m-2, SD = 26.1) and live Lophelia pertusa habitats (24.4 shrimp m-2, SD = 18.6). In non-biogenic habitats shrimp densities were <2 shrimp m-2. We conclude that CWC reef habitats clearly support greater shrimp densities than the surrounding non-biogenic habitats on the Norwegian margin.

Purser, A.; Ontrup, J.; Schoening, T.; Thomsen, L.; Tong, R.; Unnithan, V.; Nattkemper, T. W.

2013-02-01

282

R Coronae Borealis Stars formed from Double White Dwarf Mergers Jan Staff[1], Falk Herwig[2], Athira Menon[2], Wesley Even[3], Joel Tohline[1], Geoff Clayton[1], Patrick Motl[4], Chris Fryer[3], Tom Geballe[5  

E-print Network

R Coronae Borealis Stars formed from Double White Dwarf Mergers Jan Staff[1], Falk Herwig[2 Laboratory, 4: Indiana University Kokomo, 5: Gemini Observatory Introduction R Corona Borealis stars · 1M availability of N14 in the He-WD and hence production of more 18O. Fig.1: The light curve of R Coronae Bore

Herwig, Falk

283

Design and Test of a Topless Shrimp Trawl to Reduce Pelagic Fish Bycatch in the Gulf of Maine Pink Shrimp Fishery  

Microsoft Academic Search

A new innovative topless shrimp trawl was designed and tested in the flume tank, and at sea to evaluate its potential of reducing finfish bycatch in the pink shrimp fishery in the Gulf of Maine. The trawl design removed the square and the top part of the section after the square (first belly section), to become \\

Pingguo He; David Goethel; Tracey Smith

2007-01-01

284

Vaccination Enhances Early Immune Responses in White Shrimp Litopenaeus vannamei after Secondary Exposure to Vibrio alginolyticus  

PubMed Central

Background Recent work suggested that the presence of specific memory or some form of adaptive immunity occurs in insects and shrimp. Hypervariable pattern recognition molecules, known as Down syndrome cell adhesion molecules, are able to mount specific recognition, and immune priming in invertebrates. In the present study, we attempted to understand the immune response pattern of white shrimp Litopenaeus vannamei which received primary (PE) and secondary exposure (SE) to Vibrio alginolyticus. Methodology Immune parameters and proliferation of haematopoietic tissues (HPTs) of shrimp which had received PE and SE to V. alginolyticus were measured. In the PE trial, the immune parameters and proliferation of HPTs of shrimp that received heat-killed V. alginolyticus (HVa) and formalin-inactivated V. alginolyticus (FVa) were measured. Mortality, immune parameters and proliferation of HPTs of 7-day-HVa-PE shrimp (shrimp that received primary exposure to HVa after 7 days) and 7-day-FVa-PE shrimp (shrimp that received primary exposure to FVa after 7 days) following SE to live V. alginolyticus (LVa) were measured. Phagocytic activity and clearance efficiency were examined for the 7?35-day-HVa-PE and FVa-PE shrimp. Results HVa-receiving shrimp showed an earlier increase in the immune response on day 1, whereas FVa-receiving shrimp showed a late increase in the immune response on day 5. The 7-day-FVa-PE shrimp showed enhancement of immunity when encountering SE to LVa, whereas 7-day-HVa-PE shrimp showed a minor enhancement in immunity. 7-day-FVa-PE shrimp showed higher proliferation and an HPT mitotic index. Both phagocytic activity and clearance maintained higher for both HVa-PE and FVa-PE shrimp after 28 days. Conclusions HVa- and FVa-receiving shrimp showed the bacteria agglutinated prior to being phagocytised. FVa functions as a vaccine, whereas HVa functions as an inducer and can be used as an immune adjuvant. A combined mixture of FVa and HVa can serve as a “vaccine component” to modulate the immunity of shrimp. PMID:23894531

Lin, Yong-Chin; Chen, Jiann-Chu; Morni, Wan Zabidii W.; Putra, Dedi Fazriansyah; Huang, Chien-Lun; Li, Chang-Che; Hsieh, Jen-Fang

2013-01-01

285

The culture of Penaeid shrimp in ponds receiving heated discharge water from a steam electric generating station, and their use as indicators of water quality  

E-print Network

shrimp in pond 6 stocked at 5, 000 shrimp/ha with a survaval of 80. 6% 48 Growth and condition data for fed brown shrimp in pond 7 stocked at 5, 000 shrimp/ha with a survival of 81. 0% . . 49 Type and composition of food used in all experiments... at 500 shrimp/ha with a survival of 100m 65 17 Growth and condition data for fed white shrimp in pond 7 stocked at 500 shrimp/ha with a survival of 100% 66 18 Summary of results of the white shrimp experiment based on data collected on October 17...

Reitsema, Lawrence Alan

2012-06-07

286

AURORA BOREALIS - Icebreaking Deep-Sea Drilling Platform and Multi-Purpose Research Vessel  

NASA Astrophysics Data System (ADS)

Future breakthroughs in scientific deep-sea drilling critically depend on our ability to perform field expeditions with state-of-the-art technologies and modern infrastructures. This will require major investments, both in terms of generating new, as well as maintaining and renovating existing infrastructure. Diverse models for science operations are presently projected, also within the context of scientific needs after the current phase of the IODP will come to an end. In spite of its critical role in global climate and tectonic evolution, the Arctic Ocean is one of the most unexplored ocean basins of the world, its geologic and paleo-environmental history remaining largely unknown. Restricted by circulating sea ice, scientific drilling has been slow to arrive in the Arctic Ocean. This lack of data remains and represents one of the largest gaps of information in modern Earth Science. We here report on the finalised technical planning of a new European research icebreaker and deep-sea drilling vessel, the AURORA BOREALIS, designed with an all-season capability of endurance in permanently ice-covered waters. The icebreaker will be able to carry out deep-sea drilling in ice-covered deep-sea basins primarily during the more favorable summer seasons in order to fulfill the needs of the IODP or its eventual successor as a Mission-Specific Platform. AURORA BOREALIS will be the most advanced polar research vessel in the world with a multi-functional role of drilling in deep ocean basins and supporting climate and environmental research and decision support for stakeholder governments within the next 35-40 years. It will feature the highest attainable icebreaker classification, considerably surpassing in performance all currently operating research icebreakers. New technological features to be implemented include a novel hull design and specialized dynamic positioning systems for operations under closed sea-ice cover conditions with up to 2.5 m ice thickness, combined with advanced ice-forecasting support. The vessel is planned to operate routinely without ice management support by additional icebreakers, thus reducing operational costs for scientific drilling in polar regions considerably. Two moon-pools (7x7 m each) will allow routine deployment of Remotely Operated Vehicles (ROV) and Autonomous Underwater Vehicles (AUV) in ice conditions. A dedicated deep-sea drilling rig with full weather protection will enable sampling of the ocean floor in water depths between 100 and 5000 m with more than 1000 m penetration under polar conditions. The modular arrangement of science space with hangars, the possibility to flexibly equip the ship with laboratory or supply containers and with helicopters, addresses the needs of diverse disciplines in marine research. This icebreaker will allow to stage long international, interdisciplinary drilling expeditions in the central Arctic. In a long-term perspective, AURORA BOREALIS will also be used to address Antarctic research targets, both in its mode as a regular research and a scientific drilling vessel.

Lembke-Jene, L.; Biebow, N.; Kunz-Pirrung, M.; Thiede, J.; Egerton, P.; Azzolini, R.

2009-04-01

287

Biological control of Culex mosquitoes (Diptera: Culicidae) by the tadpole shrimp, Triops longicaudatus (Notostraca: Triopsidae).  

PubMed

Laboratory oviposition choice tests and behavioral observations indicated that the activity of tadpole shrimp, Triops longicaudatus (LeConte), near the water surface deterred gravid Culex quinquefasciatus Say from ovipositing. In the cities of Oasis and Riverside, Calif., tadpole shrimp significantly reduced the abundance of immature mosquitoes (Cx. tarsalis Coquillett and Cx. quinquefasciatus) probably due to lowered oviposition rates, as well as tadpole shrimp predation. Generally, mosquito oviposition rates in field ponds with tadpole shrimp were lower than that of controls, except when tadpole shrimp were very young (4 d after flooding) or when their abundance had declined late in the flooding period. When analyzed by pond, tadpole shrimp size was correlated inversely with abundance; however, differences in size or abundance did not affect their capacity to reduce mosquito populations. PMID:2033616

Tietze, N S; Mulla, M S

1991-01-01

288

Food habits of the mantis shrimp, Squilla empusa Say, in Galveston Bay, Texas  

E-print Network

were fed pieces of squid, fish or shrimp several times a week. Experimental tanks were set up with a shell hash or gravel substrate and artificial U-shaped burrows made out of PVC (polyvinyl chloride). [Matsuura and Hamano (1984) showed that mantis... (6. 91%) had empty stomachs (see Table V). Food types found in stomachs of mantis shrimp included fish, penaeid shrimp, xanthid crabs, amphipods, other crustaceans, bivalve mollusc shells, a few gastropod mollusc shells, squid, nematodes...

Cappola, Valerie Ann

2012-06-07

289

Application of Nucleic-acid-based Therapeutics for Viral Infections in Shrimp Aquaculture  

Microsoft Academic Search

Viral infections are one of the major reasons for the huge economic losses in shrimp farming. The control of viral diseases\\u000a in shrimp remains a serious challenge for the shrimp aquacultural industry, with major pathogens, such as the white spot syndrome\\u000a virus, yellow head virus, Taura syndrome virus, hepatopancreatic parvovirus, and baculoviruses, being geographically widespread.\\u000a In the absence of a

Mudagandur S. Shekhar; Yuanan Lu

2009-01-01

290

Identification of the Major Brown Shrimp (Penaeus aztecus) Allergen as the Muscle Protein Tropomyosin  

Microsoft Academic Search

Shrimp, a major seafood allergen, was investigated as a model food allergen. Extracts from both shrimp (Penaeus aztecus) meat and cooking fluid contain a substantial and similar amount of allergenic activity. A 36-kD allergen, demonstrated in both extracts by SDS-PAGE\\/Western blot analysis, reacted with 28\\/34 (82%) sera from shrimp-sensitive, skin test and RAST-positive, individuals. This allergen, named Pen a I,

C. B. Daul; M. Slattery; G. Reese; S. B. Lehrer

1994-01-01

291

Alterations in prey capture and induction of metallothioneins in grass shrimp fed cadmium-contaminated prey  

SciTech Connect

The aquatic oligochaete Limnodrilus hoffmeisteri from a Cd-contaminated cove on the Hudson River, Foundry Cove, New York, USA, has evolved Cd resistance. Past studies have focused on how the mode of detoxification of Cd by these Cd-resistant worms influences Cd trophic transfer to the grass shrimp Palaemonetes pugio. In the present study, the authors investigate reductions in prey capture in grass shrimp fed Cd-contaminated prey. They also investigate the induction of metal-binding proteins, metallothioneins, in these Cd-exposed shrimp. Grass shrimp were fed field-exposed Cd-contaminated Foundry Cove oligochaetes or laboratory-exposed Cd-contaminated Artemia salina. Following these exposures, the ability of Cd- dosed and control shrimp to capture live A. salina was compared. Results show that shrimp fed laboratory-exposed Cd-contaminated A. salina for 2 weeks exhibit significant reductions in their ability to successfully capture prey (live A. salina). Reductions in prey capture were also apparent, though not as dramatic in shrimp fed for 1 week on field-exposed Cd-contained Foundry Cove oligochaetes. Shrimp were further investigated for their subcellular distribution of Cd to examine if alterations in prey capture could be linked to saturation of Cd-metallothionein. Cd-dosed shrimp produced a low molecular weight CD-binding metallothionein protein in a dose- and time-dependent manner. Most importantly, successful prey capture decreased with increased Cd body burdens and increased Cd concentration bound to high molecular weight proteins.

Wallace, W.G.; Hoexum Brouwer, T.M.; Brouwer, M.; Lopez, G.R.

2000-04-01

292

A stochastic migration-death model of marked white shrimp populations in Moses Lake, Texas  

E-print Network

from i to j in At is a binomial event. Therefore Prob (one shrimp moves from i to 3 ~ X;(t)) "i (t) kji~t(1-kjidt) 18 If one considers only single order of magnitude at terms as having practical significance, then the expansion of the above... migra- ting in At is equal to o(at). There are 3 ways for the number of shrimp in area i, X;(t), to change in At; area i may gain a shrimp from another area or it may lose a shrimp by migration to area j or to system exterior (k0; ). Again we assert...

Rawles, Steven Douglas

1983-01-01

293

Mictomys borealis (northern bog lemming) and the Wisconsin paleoecology of the east-central Great Basin  

NASA Astrophysics Data System (ADS)

Teeth of northern bog lemming, Mictomys borealis, are reported from Cathedral and Smith Creek caves and represent the first Wisconsin remains of the genus from the Great Basin. Specimens from Cathedral Cave, Snake Range, are associated with U-series ages of 24,000 to 15,000 yr B.P. Previous work with pollen and packrat middens, dating to the same age as the Mictomys, indicate that Smith Creek Canyon contained a riparian, locally mesic community, including Picea engelmannii (spruce), Betula sp. (birch), Cercocarpus sp. (mountain mahogany), and Artemisia sp. (sagebrush) among other species. Exposed canyon slopes and the adjacent valley apparently contained a more xeric steppe community including sagebrush and Chenopodiineae species; rocky outcrop permitted Pinus flexilis (limber pine) and P. longaeva (bristlecone pine) to grow adjacent to Lake Bonneville or low in the canyon. The region apparently experienced a dry climate (not necessarily drier than today); however, Smith Creek Canyon was fed by glacial meltwater from Mt. Moriah. The northern bog lemming probably lived only in the riparian community and possibly on the north-facing slope below Cathedral Cave. Few canyons of the Snake Range would have had the unusually mesic conditions found in Smith Creek Canyon.

Mead, Jim I.; Bell, Christopher J.; Murray, Lyndon K.

1992-03-01

294

Paenibacillus borealis sp. nov., a nitrogen-fixing species isolated from spruce forest humus in Finland.  

PubMed

Seven spore-forming, nitrogen-fixing bacterial isolates from spruce forest humus in Finland were studied using the polyphasic approach. PCR amplification of 16S rRNA gene fragment with specific primers showed that the isolates were members of Paenibacillus. Levels of 16S rDNA similarity between the isolates were 97.3-100.0% and those between the isolates and other Paenibacillus species were 90.3-96.5%. The highest similarities were observed with Paenibacillus azotofixans and Paenibacillus durus. Ribotyping with EcoRI and PvuII restriction showed a high diversity in the Paenibacillus species and distinguished the isolates from these closely related species. The main whole-cell fatty acids were anteiso-C15:0 (33-48%), straight-chain C14:0 (7-21%) and C16:0 (9-20%), and iso-C15:0 (6-15%). Electron microscopy revealed a unique striped morphology of the spore surfaces. Based on phylogenetic inference and phenotypic and chemotaxonomic characteristics, these isolates are proposed as a new species, Paenibacillus borealis sp. nov., the type strain of which is KK19T (= DSM 13188T = CCUG 43137T). PMID:11321100

Elo, S; Suominen, I; Kämpfer, P; Juhanoja, J; Salkinoja-Salonen, M; Haahtela, K

2001-03-01

295

The largest gravitationally bound structures: the Corona Borealis supercluster - mass and bound extent  

NASA Astrophysics Data System (ADS)

Recent simulations of the densest portion of the Corona Borealis supercluster (A2061, A2065, A2067, and A2089) have shown virtually no possibility of extended gravitationally bound structure without inter-cluster matter. In contrast, recent analyses of the dynamics found that the clusters had significant peculiar velocities towards the supercluster centroid. In this paper we present the results of a thorough investigation of the CSC: we determine redshifts and virial masses for all eight clusters associated with the CSC; repeat the analysis of Batiste & Batuski with the inclusion of A2056 and CL1529+29; estimate the mass of the supercluster by applying the virial theorem on the supercluster scale, the caustics method, and a new procedure using the spherical collapse model (SCM) with the results of the dynamical analysis (SCM+FP); and perform a series of simulations to assess the likelihood of the CSC being a gravitationally bound supercluster. We find that the mass of the CSC is between 0.6 and 12 × 1016 h-1 M?. The dynamical analysis, caustics method and the SCM+FP indicate that the structure is collapsing, with the latter two both indicating a turn around radius of ˜12.5 h-1 Mpc. Lastly, the simulations show that with a reasonable amount of inter-cluster mass, there is likely extended bound structure in the CSC. Our results suggest that A2056, A2061, A2065, A2067, and A2089 form a gravitationally bound supercluster.

Pearson, David W.; Batiste, Merida; Batuski, David J.

2014-06-01

296

Zeta(2) Coronae Borealis, a Spectroscopic Triple System Including an Asynchronous Close Binary  

NASA Astrophysics Data System (ADS)

Using the 1-m telescope at Ritter Observatory, 36 observations of zeta (2) Coronae Borealis were taken with a fiber-fed echelle spectrograph. From these observations, zeta (2) CrB was found to be a triple system and a new spectroscopic orbit was calculated. This orbit has two periods, a 1.72357 day period for the inner binary composed of zeta (2) CrB A & B and a 251 day period for the outer binary composed of zeta (2) CrB AB & C. The inner binary period is significantly shorter than the 12.5842 day period previously calculated by Abhyankar & Sarma (1966, MNRAS, 133, 437). The inner binary possesses an essentially circular orbit (e = 0.01) while the outer binary has an eccentric orbit (e = 0.48). From the widths of their Si II 6371 Angstroms lines, the vsin i's were calculated to be 42--51 km s(-1) for zeta (2) CrB A and 7--8 km s(-1) for zeta (2) CrB B. As zeta (2) CrB A & B have similar masses, their different rotational velocities make this system a sensitive test of synchronization theories.

Mulliss, C. L.; Gordon, K. D.

1996-12-01

297

A new threat to honey bees, the parasitic phorid fly Apocephalus borealis.  

PubMed

Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD. PMID:22235317

Core, Andrew; Runckel, Charles; Ivers, Jonathan; Quock, Christopher; Siapno, Travis; Denault, Seraphina; Brown, Brian; Derisi, Joseph; Smith, Christopher D; Hafernik, John

2012-01-01

298

Hearing and hunting in red bats (lasiurus borealis, vespertilionidae): Audiogram and ear properties  

E-print Network

We examined aspects of hearing in the red bat (Lasiurus borealis) related to its use of biosonar. Evoked potential audiograms, obtained from volume-conducted auditory brainstem responses, were obtained in two bats, and the sound pressure transformation of the pinna was measured in three specimens. Field-recorded echolocation signals were analysed for comparison. The fundamental sonar search calls sweep from 45 to 30 kHz (peak energy at 35 kHz), approach-phase calls sweep from 65 to 35 kHz (peak 40 kHz) and terminal calls sweep from 70 to 30 kHz (peak 45 kHz). The most sensitive region of the audiogram extended from 10 kHz to 45–55 kHz, with maximum sensitivity as low as 20 dB SPL occurring between 25 and 30 kHz. A relative threshold minimum occurred between 40 and 50 kHz. With increasing frequency, the acoustic axis

Martin K. Obrist; Jeffrey J. Wenstrup

1997-01-01

299

The Largest Gravitationally Bound Structures: The Corona Borealis Supercluster - Mass and Bound Extent  

E-print Network

Recent simulations of the densest portion of the Corona Borealis supercluster (A2061, A2065, A2067, and A2089) have shown virtually no possibility of extended gravitationally bound structure without inter-cluster matter (Pearson & Batuski). In contrast, recent analyses of the dynamics found that the clusters had significant peculiar velocities towards the supercluster centroid (Batiste & Batuski). In this paper we present the results of a thorough investigation of the CSC: we determine redshifts and virial masses for all 8 clusters associated with the CSC; repeat the analysis of Batiste & Batuski with the inclusion of A2056 and CL1529+29; estimate the mass of the supercluster by applying the virial theorem on the supercluster scale (e.g. Small et al.), the caustics method (e.g. Reisenegger et al.), and a new procedure using the spherical collapse model (SCM) with the results of the dynamical analysis (SCM+FP); and perform a series of simulations to assess the likelihood of the CSC being a gravitat...

Pearson, David W; Batuski, David J

2014-01-01

300

The MACHO Project LMC Variable Star Inventory: III. New R Coronae Borealis Stars  

E-print Network

We report the discovery of two new R Coronae Borealis (RCB) stars in the Large Magellanic Cloud (LMC) using the MACHO project photometry database. The identification of both stars has been confirmed spectroscopically. One is a cool RCB star (T_eff about 5000 K) characterized by very strong Swan bands of C_2 and violet bands of CN, and weak or absent Balmer lines, G-band and 12C-13C bands. The second star is an example of a hot RCB star of which only 3 were previously known to exist in the Galaxy and none in the LMC. Its spectrum is characterized by several C II lines in emission. Both stars have shown deep declines of Delta V > 4 mag in brightness. The new stars are significantly fainter at maximum light than the three previously known LMC RCB stars. The amount of reddening toward these stars is somewhat uncertain but both seem to have absolute magnitudes, M_V, about half a magnitude fainter than the other three stars. Estimates of M_Bol find that the hot RCB star lies in the range of the other three stars while the cool RCB star is fainter. The two cool LMC RCB stars are the faintest at M_Bol. The discovery of these two new stars brings to five the number of known RCB stars in the LMC and demonstrates the utility of the MACHO photometric database for the discovery of new RCB stars.

C. Alcock; R. A. Allsman; D. R. Alves; T. S. Axelrod; A. Becker; D. P. Bennett; G. C. Clayton; K. H. Cook; K. C. Freeman; K. Griest; J. A. Guern; D. Kilkenny; M. J. Lehner; S. L. Marshall; B. A. Peterson; M. R. Pratt; P. J. Quinn; A. W. Rodgers; C. W. Stubbs; W. Sutherland; D. L. Welch

1996-05-07

301

The ongoing pursuit of R Coronae Borealis stars: ASAS-3 survey strikes again  

E-print Network

R Coronae Borealis stars (RCBs) are rare, hydrogen-deficient, carbon-rich supergiant variable stars that are likely the evolved merger products of pairs of CO and He white dwarfs. Only 55 RCB stars are known in our galaxy and their distribution on the sky is weighted heavily by microlensing survey field positions. A less-biased wide-area survey would provide the ability to test competing evolutionary scenarios, understand the population or populations that produce RCBs and constraint their formation rate. The ASAS-3 survey monitored the sky south of declination +28 deg since 2000 to a limiting magnitude of V=14. We searched ASAS-3 for RCB variables using a number of different methods to ensure that the probability of RCB detection was as high as possible and to reduce selection biases based on luminosity, temperature, dust production activity and shell brightness. Candidates whose light curves were visually inspected were pre-selected based on their infrared excesses due to warm dust in their circumstellar sh...

Tisserand, P; Welch, D L; Pilecki, B; Wyrzykowski, L; Kilkenny, D

2012-01-01

302

VLTI observations of the dust geometry around R Coronae Borealis stars  

E-print Network

We are investigating the formation and evolution of dust around the hydrogen-deficient supergiants known as R Coronae Borealis (RCB) stars. We aim to determine the connection between the probable merger past of these stars and their current dust-production activities. We carried out high-angular resolution interferometric observations of three RCB stars, namely RY Sgr, V CrA, and V854 Cen with the mid-IR interferometer, MIDI on the VLTI, using two telescope pairs. The baselines ranged from 30 to 60 m, allowing us to probe the dusty environment at very small spatial scales (~ 50 mas or 400 stellar radii). The observations of the RCB star dust environments were interpreted using both geometrical models and one-dimensional radiative transfer codes. From our analysis we find that asymmetric circumstellar material is apparent in RY Sgr, may also exist in V CrA, and is possible for V854 Cen. Overall, we find that our observations are consistent with dust forming in clumps ejected randomly around the RCB star so tha...

Bright, S N; Clayton, G C; De Marco, O; Leão, I C; Nordhaus, J; Gallagher, J S

2011-01-01

303

Very Large Telescope Interferometer observations of the dust geometry around R Coronae Borealis stars  

NASA Astrophysics Data System (ADS)

We are investigating the formation and evolution of dust around the hydrogen-deficient supergiants known as R Coronae Borealis (RCB) stars. We aim to determine the connection between the probable merger past of these stars and their current dust-production activities. We carried out high angular resolution interferometric observations of three RCB stars, namely RY Sgr, V CrA and V854 Cen, with the mid-infrared interferometer (MIDI) on the Very Large Telescope Interferometer (VLTI), using two telescope pairs. The baselines ranged from 30 to 60 m, allowing us to probe the dusty environment at very small spatial scales (˜50 mas or 400R?). The observations of the RCB star dust environments were interpreted using both geometrical models and one-dimensional radiative transfer codes. From our analysis, we find that asymmetric circumstellar material is apparent in RY Sgr, may also exist in V CrA and is possible for V854 Cen. Overall, we find that our observations are consistent with dust forming in clumps ejected randomly around the RCB star so that over time they create a spherically symmetric distribution of dust. However, we conclude that the determination of whether there is a preferred plane of dust ejection must wait until a time series of observations are obtained. Based on observations made with the Very Large Telescope Interferometer at Paranal Observatory under programme 079.D-0415.

Bright, S. N.; Chesneau, O.; Clayton, G. C.; De Marco, O.; Leão, I. C.; Nordhaus, J.; Gallagher, J. S.

2011-06-01

304

Millimetric observation of the SZ effect in the Corona Borealis supercluster  

E-print Network

We have observed the Corona Borealis Supercluster with the Millimeter and Infrared Testa grigia Observatory (MITO), located in the Italian Alps, at 143, 214, 272, and 353 GHz. We present a description of the measurements, data analysis, and results of the observations together with a comparison with observations performed at 33 GHz with the Very Small Array (VSA) interferometer situated at the Teide Observatory (Tenerife-Spain). Observations have been made in the direction of the supercluster towards one Cosmic Microwave Background (CMB) cold spot previously detected in a VSA temperature map. Observational strategy and data analysis are described in detail, explaining the procedures used to disentangle primary and secondary anisotropies in the resulting maps. From a first level of data analysis we find evidence in MITO data of primary anisotropy, however still with room for the presence of secondary anisotropy, especially when VSA results are included. With a second level of data analysis using map-making and the maximum entropy method we claim a weak detection of a faint signal compatible with a SZ effect characterized at most by a Comptonization parameter $y=(7.8^{+5.3}_{-4.4})\\times10^{-6}$ 68% CL. The low level of confidence in the presence of a SZ signal invite us to study this sky region with higher sensitivity and angular resolution experiments like the already planned upgraded versions of VSA and MITO.

E. S. Battistelli; M. De Petris; L. Lamagna; R. A. Watson; R. Rebolo; F. Melchiorri; R. Génova-Santos; G. Luzzi; S. De Gregori; J. A. Rubiño-Martin; R. D. Davies; R. J. Davis; K. Grainge; M. P. Hobson; R. D. E. Saunders; P. F. Scott

2006-12-20

305

Long-term Spatial and Temporal Variations of Aurora Borealis Events in the Period 1700 - 1905  

NASA Astrophysics Data System (ADS)

Catalogues and other records of aurora-borealis events were used to study the long-term spatial and temporal variation of these phenomena in the period from 1700 to 1905 in the Northern Hemisphere. For this purpose, geographic and geomagnetic coordinates were assigned to approximately 27 000 auroral events with more than 80 000 observations. They were analyzed separately in three large-scale areas: i) Europe and North Africa, ii) North America, and iii) Asia. There was a clear need to fill some gaps existing in the records so as to have a reliable proxy of solar activity, especially during the 18th century. In order to enhance the long-term variability, an 11-year smoothing window was applied to the data. Variations in the cumulative numbers of auroral events with latitude (in both geographic and geomagnetic coordinates) were used to discriminate between the two main solar sources: coronal mass ejections and high-speed streams from coronal holes. The characteristics of the associated auroras correlate differently with the solar-activity cycle.

Vázquez, M.; Vaquero, J. M.; Gallego, M. C.

2014-05-01

306

Double white dwarf mergers and elemental surface abundances in extreme helium and R Coronae Borealis stars  

E-print Network

The surface abundances of extreme helium (EHe) and R Coronae Borealis (RCB) stars are discussed in terms of the merger of a carbon-oxygen white dwarf with a helium white dwarf. The model is expressed as a linear mixture of the individual layers of both constituent white dwarfs, taking account of the specific evolution of each star. In developing this recipe from previous versions, particular attention has been given to the inter-shell abundances of the asymptotic giant branch star which evolved to become the carbon-oxygen white dwarf. Thus the surface composition of the merged star is estimated as a function of the initial mass and metallicity of its progenitor. The question of whether additional nucleosynthesis occurs during the white dwarf merger has been examined. The high observed abundances of carbon and oxygen must either originate by dredge-up from the core of the carbon-oxygen white dwarf during a cold merger or be generated directly by alpha-burning during a hot merger. The presence of large quantiti...

Jeffery, C Simon; Saio, Hideyuki

2011-01-01

307

A VSA search for the extended Sunyaev-Zel'dovich Effect in the Corona Borealis Supercluster  

E-print Network

We present interferometric imaging at 33 GHz of the Corona Borealis supercluster, using the extended configuration of the Very Small Array. A total area of 24 deg^2 has been imaged, with an angular resolution of 11 arcmin and a sensitivity of 12 mJy/beam. The aim of these observations is to search for Sunyaev-Zel'dovich (SZ) detections from known clusters of galaxies in this supercluster and for a possible extended SZ decrement due to diffuse warm/hot gas in the intercluster medium. We measure negative flux values in the positions of the ten richest clusters in the region. Collectively, this implies a 3.0-sigma detection of the SZ effect. In the clusters A2061 and A2065 we find decrements of approximately 2-sigma. Our main result is the detection of two strong and resolved negative features at -70+-12 mJy/beam (-157+-27 microK) and -103+-10 mJy/beam (-230+-23 microK), respectively, located in a region with no known clusters, near the centre of the supercluster. We discuss their possible origins in terms of pr...

Genova-Santos, R; Rebolo, R; Cleary, K; Davies, R D; Davis, R J; Dickinson, C; Falcon, N; Grainge, K; Gutíerrez, C M; Hobson, M P; Jones, M E; Kneissl, R; Lancaster, K; Padilla-Torres, C P; Saunders, R D E; Scott, P F; Watson, A; Genova-Santos, Ricardo; Rubino-Martin, Jose Alberto; Rebolo, Rafael; Cleary, Kieran; Davies, Rod D.; Davis, Richard J.; Dickinson, Clive; Falcon, Nelson; Grainge, Keith; Gutierrez, Carlos M.; Hobson, Michael P.; Jones, Michael E.; Kneissl, Ruediger; Lancaster, Katy; Padilla-Torres, Carmen P.; Saunders, Richard D.E.; Scott, Paul F.; Watson, Angela C. Taylor & Robert A.

2005-01-01

308

Discovery of Bright Galactic R Coronae Borealis and DY Persei Variables: Rare Gems Mined from ASAS  

E-print Network

We present the results of a machine-learning (ML) based search for new R Coronae Borealis (RCB) stars and DY Persei-like stars (DYPers) in the Galaxy using cataloged light curves obtained by the All-Sky Automated Survey (ASAS). RCB stars - a rare class of hydrogen-deficient carbon-rich supergiants - are of great interest owing to the insights they can provide on the late stages of stellar evolution. DYPers are possibly the low-temperature, low-luminosity analogs to the RCB phenomenon, though additional examples are needed to fully establish this connection. While RCB stars and DYPers are traditionally identified by epochs of extreme dimming that occur without regularity, the ML search framework more fully captures the richness and diversity of their photometric behavior. We demonstrate that our ML method recovers ASAS candidates that would have been missed by traditional search methods employing hard cuts on amplitude and periodicity. Our search yields 13 candidates that we consider likely RCB stars/DYPers: n...

Miller, A A; Bloom, J S; Cenko, S B; Silverman, J M; Starr, D L; Stassun, K G

2012-01-01

309

Do R Coronae Borealis Stars Form from Double White Dwarf Mergers?  

E-print Network

A leading formation scenario for R Coronae Borealis (RCB) stars invokes the merger of degenerate He and CO white dwarfs (WD) in a binary. The observed ratio of 16O/18O for RCB stars is in the range of 0.3-20 much smaller than the solar value of ~500. In this paper, we investigate whether such a low ratio can be obtained in simulations of the merger of a CO and a He white dwarf. We present the results of five 3-dimensional hydrodynamic simulations of the merger of a double white dwarf system where the total mass is 0.9 Mdot and the initial mass ratio (q) varies between 0.5 and 0.99. We identify in simulations with $q\\lesssim0.7$ a feature around the merged stars where the temperatures and densities are suitable for forming 18O. However, more 16O is being dredged-up from the C- and O-rich accretor during the merger than the amount of 18O that is produced. Therefore, on a dynamical time scale over which our hydrodynamics simulation runs, a 16O/18O ratio of ~2000 in the "best" case is found. If the conditions fou...

Staff, Jan E; Herwig, Falk; Even, Wesley; Fryer, Chris L; Motl, Patrick M; Geballe, Tom; Pignatari, Marco; Clayton, Geoffrey C; Tohline, Joel E

2012-01-01

310

R Coronae Borealis Stars in M31 from the Palomar Transient Factory  

E-print Network

We report the discovery of R Coronae Borealis (RCB) stars in the Andromeda galaxy (M31) using the Palomar Transient Factory (PTF). RCB stars are rare hydrogen-deficient, carbon-rich supergiant variables, most likely the merger products of two white dwarfs. These new RCBs, including two confirmed ones and two candidates, are the first to be found beyond the Milky Way and the Magellanic Clouds. All of M31 RCBs showed >1.5 mag irregular declines over timescales of weeks to months. Due to the limiting magnitude of our data (R~21-22 mag), these RCB stars have R~19.5 to 20.5 mag at maximum light, corresponding to M_R= -4 to -5, making them some of the most luminous RCBs known. Spectra of two objects show that they are warm RCBs, similar to the Milky Way RCBs RY Sgr and V854 Cen. We consider these results, derived from a pilot study of M31 variables, as an important proof-of-concept for the study of rare bright variables in nearby galaxies with the PTF or other synoptic surveys.

Tang, Sumin; Bildsten, Lars; Nugent, Peter; Bellm, Eric; Kulkarni, Shrinivas R; Laher, Russ; Levitan, David; Masci, Frank; Ofek, Eran O; Prince, Thomas A; Sesar, Branimir; Surace, Jason

2013-01-01

311

Do R Coronae Borealis Stars Form from Double White Dwarf Mergers?  

NASA Astrophysics Data System (ADS)

A leading formation scenario for the irregular variable R Coronae Borealis (RCB) stars invokes the merger of a degenerate Helium white dwarf with a Carbon-Oxygen white dwarf in a binary. The observed ratio of ^16O / ^18O for RCB stars is in the range of 0.3 - 20, much smaller than the solar value of 500. We report on our investigations into whether such a low oxygen isotope ratio can be obtained in simulations of double white dwarf mergers. We identify a ``shell of fire'' feature in the simulations surrounding the merged object where temperatures and densities are favorable for forming ^18O for binaries with initial mass ratios near 0.7. However, the accretion stream's impact dredges up ^16O from the Carbon-Oxygen white dwarf which forms a competing process that raises the oxygen isotope ratio. We present the most favorable scenarios we have identified for creating RCB stars in light of these competing processes and outline steps for future progress.

Motl, Patrick; Staff, Jan; Menon, Athira; Herwig, Falk; Even, Wesley; Fryer, Chris; Geballe, Tom; Pignatari, Marco; Clayton, Geoffrey; Tohline, Joel

2013-04-01

312

Dust around R Coronae Borealis stars: II. Infrared emission features in a H-poor environment  

E-print Network

Residual Spitzer/IRS spectra for a sample of 31 R Coronae Borealis (RCB) stars are presented and discussed in terms of narrow emission features superimposed on the quasi-blackbody continuous infrared emission. A broad ~6-10 um dust emission complex is seen in the RCBs showing an extreme H-deficiency. A secondary and much weaker ~11.5-15 um broad emission feature is detected in a few RCBs with the strongest ~6-10 um dust complex. The Spitzer infrared spectra reveal for the first time the structure within the ~6-10 um dust complex, showing the presence of strong C-C stretching modes at ~6.3 and 8.1 um as well as of other dust features at ~5.9, 6.9, and 7.3 um, which are attributable to amorphous carbonaceous solids with little or no hydrogen. The few RCBs with only moderate H-deficiencies display the classical 'unidentified infrared bands (UIRs)' and mid-infrared features from fullerene-related molecules. In general, the characteristics of the RCB infrared emission features are not correlated with the stellar a...

Garcia-Hernandez, D A; Lambert, D L

2013-01-01

313

Can R Coronae Borealis stars form from the merger of two helium white dwarfs?  

NASA Astrophysics Data System (ADS)

Due to orbital decay by gravitational wave radiation, some close binary helium white dwarfs are expected to merge within a Hubble time. The immediate merger products are believed to be He-rich subdwarf O (sdO) stars, essentially helium main-sequence stars. We present new evolution calculations for these post-merger stars beyond the core He-burning phase. The most massive He-rich sdO stars develop a strong He-burning shell and evolve to become He-rich giants. We include nucleosynthesis calculations following the merger of 0.4 M? He white dwarf pairs with metallicities Z= 0.0001, 0.004, 0.008 and 0.02. The surface chemistries of the resulting giants are in partial agreement with the observed abundances of R Coronae Borealis (R CrB) and extreme He stars. Such stars might represent a third, albeit rare, evolution channel for the latter, in addition to the CO+He white dwarf merger and the very late thermal pulse channels proposed previously. We confirm a recent suggestion that Li seen in R CrB stars could form naturally during the hot phase of a merger in the presence of 3He from the donor white dwarf.

Zhang, Xianfei; Jeffery, C. Simon

2012-10-01

314

The MACHO Project LMC Variable Star Inventory: X. The R Coronae Borealis Stars  

E-print Network

We report the discovery of eight new R Coronae Borealis (RCB) stars in the Large Magellanic Cloud (LMC) using the MACHO project photometry database. The discovery of these new stars increases the number of known RCB stars in the LMC to thirteen. We have also discovered four stars similar to the Galactic variable DY Per. These stars decline much more slowly and are cooler than the RCB stars. The absolute luminosities of the Galactic RCB stars are unknown since there is no direct measurement of the distance to any Galactic RCB star. Hence, the importance of the LMC RCB stars. We find a much larger range of absolute magnitudes (M(V) = -2.5 to -5 mag) than inferred from the small pre-MACHO sample of LMC RCB stars. It is likely that there is a temperature - M(V)relationship with the cooler stars being intrinsically fainter. Cool (~5000 K) RCB stars are much more common than previously thought based on the Galactic RCB star sample. Using the fairly complete sample of RCB stars discovered in the MACHO fields, we have estimated the likely number of RCB stars in the Galaxy to be ~3,200. The SMC MACHO fields were also searched for RCB stars but none were found.

C. Alcock; R. A. Allsman; D. R. Alves; T. S. Axelrod; A. Becker; D. P. Bennett; Geoffrey C. Clayton; K. H. Cook; N. Dalal; A. J. Drake; K. C. Freeman; M. Geha; K. D. Gordon; K. Griest; D. Kilkenny; M. J. Lehner; S. L. Marshall; D. Minniti; K. A. Misselt; C. A. Nelson; B. A. Peterson; P. Popowski; M. R. Pratt; P. J. Quinn; C. W. Stubbs; W. Sutherland; A. Tomaney; T. Vandehei; D. L. Welch

2001-02-15

315

Long-term variations in dust production in R Coronae Borealis  

NASA Technical Reports Server (NTRS)

Several searches for periodicities in the historical visible light curves of RCB stars have found that the intervals between declines are random. This paper reexamines 70 declines of R Coronae Borealis since 1853 using one homogeneous data set, the AAVSO light curve. In this data set, pairs of consecutive declines also show a random distribution of intervals. However, if the sequence of declines is examined, there are semiperiodic variations between times of high- and low-decline activity on a time scale of a few years. Near-IR photometry of RCB stars indicates that there are large semiperiodic variations in the amount of dust being produced which have similar time scales. Possible interpretations of a semiperiodic variation in dust formation rates in RCB stars are presented. One is a magnetic activity cycle resulting in 'spots' on the star over which dust formation takes place. Such a magnetic activity cycle is similar to the solar cycle. Another is the changes in the period and amplitude of the pulsations over several years affecting the efficiency of dust production.

Clayton, Geoffrey C.; Whitney, Barbara A.; Mattei, Janet A.

1993-01-01

316

The Circumstellar Environment of R Coronae Borealis: White Dwarf Merger or Final Helium Shell Flash?  

E-print Network

In 2007, R Coronae Borealis (R CrB) went into an historically deep and long decline. In this state, the dust acts like a natural coronagraph at visible wavelengths, allowing faint nebulosity around the star to be seen. Imaging has been obtained from 0.5 to 500 micron with Gemini/GMOS, HST/WFPC2, Spitzer/MIPS, and Herschel/SPIRE. Several of the structures around R CrB are cometary globules caused by wind from the star streaming past dense blobs. The estimated dust mass of the knots is consistent with their being responsible for the R CrB declines if they form along the line of sight to the star. In addition, there is a large diffuse shell extending up to 4 pc away from the star containing cool 25 K dust that is detected all the way out to 500 micron. The SED of R CrB can be well fit by a 150 AU disk surrounded by a very large diffuse envelope which corresponds to the size of the observed nebulosity. The total masses of the disk and envelope are 10^-4 and 10^2 M(Sun), respectively, assuming a gas-to-dust ratio ...

Clayton, Geoffrey C; Stanford, S Adam; Whitney, B A; Honor, J; Babler, B; Barlow, M J; Gordon, K D; Andrews, J E; Geballe, T R; Bond, Howard E; De Marco, O; Lawson, W A; Sibthorpe, B; Olofsson, G; Polehampton, E; Gomez, H L; Matsuura, M; Hargrave, P C; Ivison, R J; Wesson, R; Leeks, S J; Swinyard, B M; Lim, T L

2011-01-01

317

R Coronae Borealis Stars in M31 from the Palomar Transient Factory  

NASA Astrophysics Data System (ADS)

We report the discovery of R Coronae Borealis (RCB) stars in the Andromeda galaxy (M31) using the Palomar Transient Factory (PTF). RCB stars are rare hydrogen-deficient, carbon-rich supergiant variables, most likely the merger products of two white dwarfs. These new RCBs, including two confirmed ones and two candidates, are the first to be found beyond the Milky Way and the Magellanic Clouds. All of M31 RCBs showed >1.5 mag irregular declines over timescales of weeks to months. Due to the limiting magnitude of our data (R ? 21-22 mag), these RCB stars have R ? 19.5-20.5 mag at maximum light, corresponding to MR = -4 to -5, making them some of the most luminous RCBs known. Spectra of two objects show that they are warm RCBs, similar to the Milky Way RCBs RY Sgr and V854 Cen. We consider these results, derived from a pilot study of M31 variables, as an important proof-of-concept for the study of rare bright variables in nearby galaxies with the PTF or other synoptic surveys.

Tang, Sumin; Cao, Yi; Bildsten, Lars; Nugent, Peter; Bellm, Eric; Kulkarni, Shrinivas R.; Laher, Russ; Levitan, David; Masci, Frank; Ofek, Eran O.; Prince, Thomas A.; Sesar, Branimir; Surace, Jason

2013-04-01

318

Coordinated Ginga, IUE, and VLA observations of stellar activity in Sigma(2) Coronae Borealis  

NASA Technical Reports Server (NTRS)

Observations of the active cool star binary system Sigma(2) Corona Borealis with the Large Area Counters on the Ginga X-ray satellite over 2.5 d, or about two orbital periods, are reported. Throughout the observations, Sigma(2) CrB exhibited X-ray variability on time scales ranging from tens of minutes to hours. The X-ray light curve shows evidence of flaring during the course of the observations. The summed X-ray pulse height spectrum from flaring events compared with similar spectra from quiescent periods indicates an increase in coronal temperature. Periodogram analysis of the entire X-ray light curve shows a possible periodicity at about 0.40-0.44 d, with no strong signal at the orbital period or 1/2 of the orbital period. Coordinated multiwavelength observations of IUE and the VLA indicate both UV and microwave flaring during one X-ray outburst. The quiescent microwave spectrum is not consistent with a thermal gyrosynchrotron process; nonthermal gyrosynchrotron radiation is argued to be the most likely emission process.

Stern, R. A.; Uchida, Y.; Walter, F.; Vilhu, O.; Hannikainen, D.; Brown, A.; Veale, A.; Haisch, B. M.

1992-01-01

319

Zeta^2 Coronae Borealis, a Spectroscopic Triple System Including an Asynchronous Close Binary  

E-print Network

Using the 1-m telescope at Ritter Observatory, we took 36 observations of zeta^2 Coronae Borealis with a fiber-fed echelle spectrograph. From these observations, zeta^2 CrB was found to be a triple system and a new spectroscopic orbit was calculated. This orbit has two periods, a 1.72357 day period for the inner binary composed of zeta^2 CrB A & B and a 251 day period for the outer binary composed of zeta^2 CrB AB & C. The inner binary is a double-lined spectroscopic binary composed of two B7 V stars. The inner binary's center of mass (zeta^2 CrB AB) describes a long-period single-lined variation identified with the outer binary. The inner binary period is significantly shorter than the 12.5842 day period previously calculated by Abhyankar & Sarma (1966). The inner binary possesses an essentially circular orbit (e = 0.01) while the outer binary has an eccentric orbit (e = 0.48). From the widths of their Si II 6371 A lines, the vsini's were calculated to be 46 +/- 7 km s^-1 for zeta^2 CrB A and 7.5 +/- 2 km s^-1 for zeta^2 CrB B. As zeta^2 CrB A & B have similar masses, their different rotational velocities make this system a sensitive test of synchronization theories.

K. D. Gordon; C. L. Mulliss

1996-11-12

320

The spatial distribution of galaxies within the CMB cold spot in the Corona Borealis supercluster  

E-print Network

We study the spatial distribution and colours of galaxies within the region covered by the cold spot in the cosmic microwave background (CMB) recently detected by the Very Small Array (VSA; Genova-Santos et al. 2005, 2008) towards the Corona Borealis supercluster (CrB-SC). The spot is in the northern part of a region with a radius ~1 degree (~5 Mpc at the redshift of CrB-SC) enclosing the clusters Abell 2056, 2065, 2059 and 2073, and where the density of galaxies, excluding the contribution from those clusters, is ~2 times higher than the mean value in typical intercluster regions of the CrB-SC. Two of such clusters (Abell 2056 and 2065) are members of the CrB-SC, while the other two are in the background. This high density intercluster region is quite inhomogeneous, being the most remarkable feature a large concentration of galaxies in a narrow filament running from Abell 2065 with a length of ~35 arcmin (~3 Mpc at the redshift of CrB-SC) in the SW-NE direction. This intercluster population of galaxies proba...

Padilla-Torres, C P; Rebolo, R; Genova-Santos, R; Rubiño-Martín, J A

2009-01-01

321

Dust around R Coronae Borealis stars: I. Spitzer/IRS observations  

E-print Network

Spitzer/IRS spectra from 5 to 37 um for a complete sample of 31 R Coronae Borealis stars (RCBs) are presented. These spectra are combined with optical and near-infrared photometry of each RCB at maximum light to compile a spectral energy distribution (SED). The SEDs are fitted with blackbody flux distributions and estimates made of the ratio of the infrared flux from circumstellar dust to the flux emitted by the star. Comparisons for 29 of the 31 stars are made with the IRAS fluxes from three decades earlier: Spitzer and IRAS fluxes at 12 um and 25 um are essentially equal for all but a minority of the sample. For this minority, the IRAS to Spitzer flux ratio exceeds a factor of three. The outliers are suggested to be stars where formation of a dust cloud or dust puff is a rare event. A single puff ejected prior to the IRAS observations may have been reobserved by Spitzer as a cooler puff at a greater distance from the RCB. RCBs which experience more frequent optical declines have, in general, a circumstellar...

Garcia-Hernandez, D A; Lambert, David L

2011-01-01

322

The Circumstellar Environment of R Coronae Borealis: White Dwarf Merger or Final Helium Shell Flash?  

NASA Astrophysics Data System (ADS)

In 2007, R Coronae Borealis (R CrB) went into an historically deep and long decline. In this state, the dust acts like a natural coronograph at visible wavelengths, allowing faint nebulosity around the star to be seen. Several of the structures around R CrB are cometary globules caused by wind from the star streaming past dense blobs. The estimated dust mass of the knots is consistent with their being responsible for the R CrB declines if they form along the line of sight to the star. In addition, there is a large diffuse shell extending up to 4 pc away from the star containing cool 25 K dust that is detected all the way out to 500 µm. The evidence pointing toward a white-dwarf merger or a final-helium-shell flash origin for R CrB is contradictory. The shell and the cometary knots are consistent with a fossil planetary nebula. Along with the fact that R CrB shows significant Lithium in its atmosphere, this supports the final-helium-shell flash. However, the relatively high inferred mass of R CrB and its high fluorine abundance support a white-dwarf merger.

Clayton, Geoffrey C.

2012-01-01

323

Dust Around R Coronae Borealis Stars. II. Infrared Emission Features in an H-poor Environment  

NASA Astrophysics Data System (ADS)

Residual Spitzer/Infrared Spectrograph spectra for a sample of 31 R Coronae Borealis (RCB) stars are presented and discussed in terms of narrow emission features superimposed on the quasi-blackbody continuous infrared emission. A broad ~6-10 ?m dust emission complex is seen in the RCBs showing an extreme H-deficiency. A secondary and much weaker ~11.5-15 ?m broad emission feature is detected in a few RCBs with the strongest ~6-10 ?m dust complex. The Spitzer infrared spectra reveal for the first time the structure within the ~6-10 ?m dust complex, showing the presence of strong C-C stretching modes at ~6.3 and 8.1 ?m as well as of other dust features at ~5.9, 6.9, and 7.3 ?m, which are attributable to amorphous carbonaceous solids with little or no hydrogen. The few RCBs with only moderate H-deficiencies display the classical "unidentified infrared bands (UIRs)" and mid-infrared features from fullerene-related molecules. In general, the characteristics of the RCB infrared emission features are not correlated with the stellar and circumstellar properties, suggesting that the RCB dust features may not be dependent on the present physical conditions around RCB stars. The only exception seems to be the central wavelength of the 6.3 ?m feature, which is blueshifted in those RCBs showing also the UIRs, i.e., the RCBs with the smallest H deficiency.

García-Hernández, D. A.; Kameswara Rao, N.; Lambert, D. L.

2013-08-01

324

R Coronae Borealis stars in the Galactic Bulge discovered by EROS-2  

E-print Network

Rare types of variable star may give unique insight into short-lived stages of stellar evolution. The systematic monitoring of millions of stars and advanced light curve analysis techniques of microlensing surveys make them ideal for discovering also such rare variable stars. One example is the R Coronae Borealis (RCB) stars, a rare type of evolved carbon-rich supergiant. We have conducted a systematic search of the EROS-2 database for the Galactic catalogue Bulge and spiral arms to find Galactic RCB stars. The light curves of $\\sim$100 million stars, monitored for 6.7 years (from July 1996 to February 2003), have been analysed to search for the main signature of RCB stars, large and rapid drops in luminosity. Follow-up spectroscopy has been used to confirm the photometric candidates. We have discovered 14 new RCB stars, all in the direction of the Galactic Bulge, bringing the total number of confirmed Galactic RCB stars to about 51. After reddening correction, the colours and absolute magnitudes of at least ...

Tisserand, P; Wood, P R; Lesquoy, E; Beaulieu, J P; Milsztajn, A; Hamadache, C; Afonso, C; Albert, J N; Andersen, J; Ansari, R; Aubourg, E; Bareyre, P; Charlot, X; Coutures, C; Ferlet, R; Fouqué, P; Glicenstein, J F; Goldman, B; Gould, A; Gros, M; Haïssinski, J; De Kat, J; Guillou, L Le; Loup, C; Magneville, C; Maurice, E; Maury, A; Moniez, M; Palanque-Delabrouille, Nathalie; Perdereau, O; Rahal, Y; Rich, J; Spiro, M; Vidal-Madjar, A; Zylberajch, S

2008-01-01

325

Detection of an X-ray flare in the RS CVn binary Sigma Coronae Borealis  

NASA Technical Reports Server (NTRS)

The detection of an X-ray flare in the RS CVn binary Sigma Coronae Borealis with the Monitor Proportional Counter on the Einstein Observatory is described. During the 513 min of observation, an X-ray flare of 208 min duration was detected at a significance level of 26 sigma in the 1.19-10.16 keV band. The rise time of the flare is between 25 and 70 min and the decay time is greater than or equal to 34 min. The X-ray luminosity at the flare maximum is found to be 6 x 10 to the 30th erg/s and the total energy radiated in X-rays during the flare is 2 x 10 to the 34th erg. The energy spectrum in the flaring state is found to be harder (temperature T about 2.5 x 10 to the 7th K) compared to the one observed in the quiescent state (T about 6 x 10 to the 6th K). Applying the coronal loop model, the loop parameters are calculated and compared for the X-ray flares observed in the various RS CVn binaries and the sun. The significance of the differences in the observed and derived parameters of the X-ray flares is briefly discussed.

Agrawal, P. C.; Rao, A. R.; Riegler, G. R.

1986-01-01

326

Tracking down R Coronae Borealis stars from their mid-infrared WISE colours  

E-print Network

R Coronae Borealis stars (RCBs) are hydrogen-deficient and carbon-rich supergiant stars. They are very rare, as only $\\sim50$ are actually known in our Galaxy. Interestingly, RCBs are strongly suspected to be the evolved merger product of two white dwarfs and could therefore be an important tool to understand Supernovae type Ia in the double degenerate scenario. Constraints on the spatial distribution and the formation rate of such stars are needed to picture their origin and test it in the context of actual population synthesis results. To do so, it is crucial to increase significantly the number of known RCBs. With an absolute magnitude $\\mathrm{M_V\\sim-5}$ and a bright/hot circumstellar shell made of amorphous carbon grains, RCBs are really distinctive stars. Mono-epoch mid-infrared data can help us to discriminate RCBs among other dust-producing stars. The aim is to produce from the WISE and 2MASS infrared catalogues a new catalogue of reasonable size, enriched with RCB stars. Colour-Colour cuts used on a...

Tisserand, Patrick

2011-01-01

327

Detections of CO in the Circumstellar Shells of R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

It has been known for 60 years that the declines of R Coronae Borealis (RCB) stars are caused by circumstellar dust formation. The declines occur suddenly and without warning. No spectroscopic changes have yet been noted near the beginning of the decline, which might be linked to the cooling gas that must be condensing to form the dust. The mechanism of mass loss and dust formation is still a mystery. New observational evidence along with models of the carbon chemistry around RCB stars suggest that dust may condense close to the star. Shocks propagating through the outer atmospheres encourage non-equilibrium conditions where the conditions for carbon nucleation may be present. CO is thought to be a critical gas coolant in this process. We report detections of the CO 4th positive system lines in STIS UV spectra of two RCB stars and of the CO v=2 bands in the near-IR for several RCB stars. These observations are being used to model the temperature and density of condensing gas around these stars.

Clayton, G. C.; Hanson, M. M.; Gordon, K. D.; Ayres, T. R.

1999-12-01

328

A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis  

PubMed Central

Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD. PMID:22235317

Core, Andrew; Runckel, Charles; Ivers, Jonathan; Quock, Christopher; Siapno, Travis; DeNault, Seraphina; Brown, Brian; DeRisi, Joseph; Smith, Christopher D.; Hafernik, John

2012-01-01

329

Sasa borealis stem extract attenuates hepatic steatosis in high-fat diet-induced obese rats.  

PubMed

The aim of the current study is to examine the improving effect of Sasa borealis stem (SBS) extract extracts on high-fat diet (HFD)-induced hepatic steatosis in rats. To determine the hepatoprotective effect of SBS, we fed rats a normal regular diet (ND), HFD, and HFD supplemented with 150 mg/kg body weight (BW) SBS extracts for five weeks. We found that the body weight and liver weight of rats in the HFD + SBS group were significantly lower than those in the HFD group. Significantly lower serum total cholesterol (TC) and triglyceride (TG) concentrations were observed in the SBS-supplemented group compared with the HFD group. We also found that the HFD supplemented with SBS group showed dramatically reduced hepatic lipid accumulation compared to the HFD alone group, and administration of SBS resulted in dramatic suppression of TG, TC in the HFD-induced fatty liver. In liver gene expression within the SBS treated group, PPAR? was significantly increased and SREBP-1c was significantly suppressed. SBS induced a significant decrease in the hepatic mRNA levels of PPAR?, FAS, ACC1, and DGAT2. In conclusion, SBS improved cholesterol metabolism, decreased lipogenesis, and increased lipid oxidation in HFD-induced hepatic steatosis in rats, implying a potential application in treatment of non-alcoholic fatty liver disease. PMID:24905748

Song, Yuno; Lee, Soo-Jung; Jang, Sun-Hee; Ha, Ji Hee; Song, Young Min; Ko, Yeoung-Gyu; Kim, Hong-Duck; Min, Wongi; Kang, Suk Nam; Cho, Jae-Hyeon

2014-06-01

330

Sasa borealis Stem Extract Attenuates Hepatic Steatosis in High-Fat Diet-induced Obese Rats  

PubMed Central

The aim of the current study is to examine the improving effect of Sasa borealis stem (SBS) extract extracts on high-fat diet (HFD)-induced hepatic steatosis in rats. To determine the hepatoprotective effect of SBS, we fed rats a normal regular diet (ND), HFD, and HFD supplemented with 150 mg/kg body weight (BW) SBS extracts for five weeks. We found that the body weight and liver weight of rats in the HFD + SBS group were significantly lower than those in the HFD group. Significantly lower serum total cholesterol (TC) and triglyceride (TG) concentrations were observed in the SBS-supplemented group compared with the HFD group. We also found that the HFD supplemented with SBS group showed dramatically reduced hepatic lipid accumulation compared to the HFD alone group, and administration of SBS resulted in dramatic suppression of TG, TC in the HFD-induced fatty liver. In liver gene expression within the SBS treated group, PPAR? was significantly increased and SREBP-1c was significantly suppressed. SBS induced a significant decrease in the hepatic mRNA levels of PPAR?, FAS, ACC1, and DGAT2. In conclusion, SBS improved cholesterol metabolism, decreased lipogenesis, and increased lipid oxidation in HFD-induced hepatic steatosis in rats, implying a potential application in treatment of non-alcoholic fatty liver disease. PMID:24905748

Song, Yuno; Lee, Soo-Jung; Jang, Sun-Hee; Ha, Ji Hee; Song, Young Min; Ko, Yeoung-Gyu; Kim, Hong-Duck; Min, Wongi; Kang, Suk Nam; Cho, Jae-Hyeon

2014-01-01

331

On the origin of the Vastitas Borealis Formation in Chryse and Acidalia Planitiae, Mars  

NASA Astrophysics Data System (ADS)

geologic history of the northern plains of Mars has been extensively debated. Specifically, the Vastitas Borealis Formation (VBF) represents an enigmatic surface unit that exhibits flow morphologies at its boundary, extensive surface fracturing, tens of thousands of small mounds, and unique crater morphologies. Here we test the hypothesis that the VBF in the region of Chryse and Acidalia Planitiae, Mars, originated through the compaction and later expulsion of fluid-laden sediments sourced from the shallow subsurface. We find that the morphological, thermophysical, and spectral properties of the VBF marginal unit, in addition to the recent identification of fine-grained sedimentary layers in the shallow subsurface, are all consistent with such a formation mechanism. Estimates of volume loss based on "collar-like" morphologies present on high-standing buttes suggest that a minimum fluid volume of ~13,500 km3 was expelled from the subsurface, making the VBF a significant ancient hydrologic reservoir on the Martian surface. This formation mechanism lends additional insight into the sedimentary and aqueous history of the northern plains of Mars and unites morphologic, spectral, thermophysical, and structural observations under one consistent formation hypothesis.

Salvatore, M. R.; Christensen, P. R.

2014-12-01

332

R CORONAE BOREALIS STARS IN M31 FROM THE PALOMAR TRANSIENT FACTORY  

SciTech Connect

We report the discovery of R Coronae Borealis (RCB) stars in the Andromeda galaxy (M31) using the Palomar Transient Factory (PTF). RCB stars are rare hydrogen-deficient, carbon-rich supergiant variables, most likely the merger products of two white dwarfs. These new RCBs, including two confirmed ones and two candidates, are the first to be found beyond the Milky Way and the Magellanic Clouds. All of M31 RCBs showed >1.5 mag irregular declines over timescales of weeks to months. Due to the limiting magnitude of our data (R Almost-Equal-To 21-22 mag), these RCB stars have R Almost-Equal-To 19.5-20.5 mag at maximum light, corresponding to M{sub R} = -4 to -5, making them some of the most luminous RCBs known. Spectra of two objects show that they are warm RCBs, similar to the Milky Way RCBs RY Sgr and V854 Cen. We consider these results, derived from a pilot study of M31 variables, as an important proof-of-concept for the study of rare bright variables in nearby galaxies with the PTF or other synoptic surveys.

Tang Sumin; Bildsten, Lars [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States); Cao Yi; Bellm, Eric; Kulkarni, Shrinivas R.; Levitan, David; Prince, Thomas A.; Sesar, Branimir [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Nugent, Peter [Computational Cosmology Center, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720 (United States); Laher, Russ; Surace, Jason [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States); Masci, Frank [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Ofek, Eran O. [Benoziyo Center for Astrophysics and the Helen Kimmel Center for Planetary Science, Weizmann Institute of Science, 76100 Rehovot (Israel)

2013-04-20

333

68 FR 48592 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AM23 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 10 AGENCY: National...for the shrimp fishery of the Gulf of Mexico; request for...

2003-08-14

334

69 FR 1538 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AM23 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 10 AGENCY: National...Plan for the Shrimp Fishery of the Gulf of Mexico (Amendment 10), as...

2004-01-09

335

71 FR 56039 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AS15 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 13 AGENCY: National...Plan for the Shrimp Fishery of the Gulf of Mexico (Amendment 13), as...

2006-09-26

336

68 FR 56252 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AM23 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 10 AGENCY: National...Plan for the Shrimp Fishery of the Gulf of Mexico (Amendment 10), as...

2003-09-30

337

67 FR 51074 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AO51 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 11 AGENCY: National...Plan for the Shrimp Fishery of the Gulf of Mexico (Amendment 11), as...

2002-08-07

338

64 FR 23039 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AK32 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Certification of Bycatch Reduction...Plan for the Shrimp Fishery of the Gulf of Mexico (FMP), NMFS proposes...

1999-04-29

339

63 FR 18139 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AH52 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 9 AGENCY: National...Plan for the Shrimp Fishery of the Gulf of Mexico (FMP). Amendment 9...

1998-04-14

340

67 FR 8503 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AO51 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 11 AGENCY: National...Plan for the Shrimp Fishery of the Gulf of Mexico (Amendment 11), as...

2002-02-25

341

71 FR 17062 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AS15 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Amendment 13 AGENCY: National...Plan for the Shrimp Fishery of the Gulf of Mexico (Amendment 13), as...

2006-04-05

342

64 FR 37690 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AK32 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico; Certification of Bycatch Reduction...Plan for the Shrimp Fishery of the Gulf of Mexico (FMP), NMFS establishes...

1999-07-13

343

73 FR 8219 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fisheries of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AU59 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fisheries of the Gulf of Mexico; Revisions to Bycatch Reduction...Plan for the Shrimp Fishery of the Gulf of Mexico (Gulf FMP) and the Fishery...

2008-02-13

344

DISTRIBUTION AND ABUNDANCE OF BURROWING SHRIMP IN TWO OREGON ESTUARIES AND IMPLICATIONS FOR ESTUARINE-SCALE NITROGEN DYNAMICS  

EPA Science Inventory

Thalassinid burrowing shrimp (Neotrypaea californiensis and Upogebia pugettensis) inhabit large expanses of Pacific estuarine tide flats, from British Columbia to Baja California. The spatial distribution of shrimp populations within estuaries has rarely been quantified because ...

345

IMPACT OF BURROWING SHRIMP POPULATIONS ON C, N CYCLING AND WATER QUALITY IN WESTERN NORTH AMERICAN TEMPERATE ESTUARIES  

EPA Science Inventory

Thalassinid burrowing shrimp (predominantly, Neotrypaea californiensis and Upogebia pugettensis) inhabit large expanses of tide flats in North American Pacific estuaries, from British Columbia to Baja California. Feeding, burrowing, and burrow irrigation by burrowing shrimp can ...

346

IMPACT OF BURROWING SHRIMP POPULATIONS ON NITROGEN CYCLING AND WATER QUALITY IN WESTERN NORTH AMERICAN TEMPERATE ESTUARIES  

EPA Science Inventory

Thalassinid burrowing shrimp (predominantly, Neotrypaea californiensis and Upogebia pugettensis) inhabit large expanses of tide flats in North American Pacific estuaries, from British Columbia to Baja California. Feeding, burrowing, and burrow irrigation by burrowing shrimp can ...

347

76 FR 67418 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit for the Preliminary Results...shrimp'') from the Socialist Republic of Vietnam (``Vietnam'') to December 9, 2011. The period of...

2011-11-01

348

76 FR 55350 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit for the Preliminary Results...shrimp'') from the Socialist Republic of Vietnam (``Vietnam'') to November 9, 2011. The period of...

2011-09-07

349

76 FR 73594 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit for the Preliminary Results...shrimp'') from the Socialist Republic of Vietnam (``Vietnam'') to January 9, 2012. The period of...

2011-11-29

350

77 FR 63786 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Notice of Court Decision...  

Federal Register 2010, 2011, 2012, 2013

...Shrimp From the Socialist Republic of Vietnam: Notice of Court Decision Not in Harmony...Review of Grobest & I Mei Industrial (Vietnam) Co., Ltd., and Notice of Amended...shrimp'') from the Socialist Republic of Vietnam (``Vietnam'') for the period...

2012-10-17

351

78 FR 57352 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Preliminary Results of Re...  

Federal Register 2010, 2011, 2012, 2013

...Shrimp From the Socialist Republic of Vietnam: Preliminary Results of Re-conducted...Review of Grobest & I-Mei Industrial (Vietnam) Co., Ltd. and Intent Not To Revoke...shrimp from the Socialist Republic of Vietnam (``Vietnam''). The period of...

2013-09-18

352

76 FR 49729 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit...  

Federal Register 2010, 2011, 2012, 2013

...Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Extension of Time Limit for Final Results of Antidumping...shrimp'') from the Socialist Republic of Vietnam (``Vietnam''). The review covers the period February...

2011-08-11

353

75 FR 28760 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...  

Federal Register 2010, 2011, 2012, 2013

...0648-AY58 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of Mexico and South Atlantic; Revisions...Plan for the Shrimp Fishery of the Gulf of Mexico (Gulf FMP) and the Fishery...

2010-05-24

354

Shrimp Lipids: A Source of Cancer Chemopreventive Compounds  

PubMed Central

Shrimp is one of the most popular seafoods worldwide, and its lipids have been studied for biological activity in both, muscle and exoskeleton. Free fatty acids, triglycerides, carotenoids, and other lipids integrate this fraction, and some of these compounds have been reported with cancer chemopreventive activities. Carotenoids and polyunsaturated fatty acids have been extensively studied for chemopreventive properties, in both in vivo and in vitro studies. Their mechanisms of action depend on the lipid chemical structure and include antioxidant, anti-proliferative, anti-mutagenic, and anti-inflammatory activities, among others. The purpose of this review is to lay groundwork for future research about the properties of the lipid fraction of shrimp. PMID:24135910

López-Saiz, Carmen-María; Suárez-Jiménez, Guadalupe-Miroslava; Plascencia-Jatomea, Maribel; Burgos-Hernández, Armando

2013-01-01

355

Issues, impacts, and implications of shrimp aquaculture in Thailand  

Microsoft Academic Search

Water quality impacts to and from intensive shrimp aquaculture in Thailand are substantial. Besides the surface and subsurface\\u000a salinization of freshwaters, loadings of solids, oxygen-consuming organic matter, and nutrients to receiving waters are considerable\\u000a when the cumulative impacts from water exchange during the growout cycle, pond drainage during harvesting, and illegal pond\\u000a sediment disposal are taken into account. Although just

Forrest E. Dierberg; Woraphan Kiattisimkul

1996-01-01

356

Concurrent production of chitin from shrimp shells and fungi.  

PubMed

Crustacean shells constitute the traditional and current commercial source of chitin. Conversely, the control of fungal fermentation processes to produce quality chitin makes fungal mycelia an attractive alternative source. Therefore, the exploitation of both of these sources to produce chitin in a concurrent process should be advantageous and is reported here. Three proteolytic Aspergillus niger (strains 0576, 0307 and 0474) were selected from a screening for protease activity from among 34 zygomycete and deuteromycete strains. When fungi and shrimp shell powder were combined in a single reactor, the release of protease by the fungi facilitated the deproteinization of shrimp-shell powder and the release of hydrolyzed proteins. The hydrolyzed proteins in turn were utilized as a nitrogen source for fungal growth, leading to a lowering of the pH of the fermentation medium, thereby further enhancing the demineralization of the shrimp-shell powder. The shrimp-shell powders and fungal mycelia were separated after fermentation and extracted for chitin with 5% LiCl/DMAc solvent. Chitin isolates from the shells were found to have a protein content of less than 5%, while chitin isolates from the three fungal mycelia strains had protein content in the range of 10-15%. The relative molecular weights as estimated by GPC for all chitin samples were in the 10(5) dalton range. All samples displayed characteristic profiles for chitin in their FTIR and solid-state NMR spectra. All chitin samples evaluated with MTT and Neutral Red assays with three commercial cell lines did not display cytotoxic effects. PMID:11376610

Teng, W L; Khor, E; Tan, T K; Lim, L Y; Tan, S C

2001-06-01

357

An environmental simulation of a shrimp mariculture pond  

E-print Network

Zooplankton O IO CL Ill Qp ir Shrimp O (0 O n. E Ll dl C3 Settling Feces & Mortalities Grazing Cll f4 EO I L3 Detritus Pool Benthic Fauna Intr oduc ed Feed Figure 1. Pond Model Biomass Flows Photosynthesis Dissolved Oxygen... the fluctuations of oxygen in the pond in response to photosynthesis and metabolism. Primary Producers (Phytoplankton) Primary producers include all photosynthetic organisms in a pond. While this ignores the competition i' or nutrients within phytoplankton...

Whitson, John Lee

2012-06-07

358

U-Pb SHRIMP dating of uraniferous opals  

USGS Publications Warehouse

U-Pb and U-series analyses of four U-rich opal samples using sensitive high-resolution ion microprobe (SHRIMP) demonstrate the potential of this technique for the dating of opals with ages ranging from several tens of thousand years to millions of years. The major advantages of the technique, compared to the conventional thermal ionisation mass spectrometry (TIMS), are the high spatial resolution (???20 ??m), the ability to analyse in situ all isotopes required to determine both U-Pb and U-series ages, and a relatively short analysis time which allows obtaining a growth rate of opal as a result of a single SHRIMP session. There are two major limitations to this method, determined by both current level of development of ion probes and understanding of ion sputtering processes. First, sufficient secondary ion beam intensities can only be obtained for opal samples with U concentrations in excess of ???20 ??g/g. However, this restriction still permits dating of a large variety of opals. Second, U-Pb ratios in all analyses drifted with time and were only weakly correlated with changes in other ratios (such as U/UO). This drift, which is difficult to correct for, remains the main factor currently limiting the precision and accuracy of the U-Pb SHRIMP opal ages. Nevertheless, an assumption of similar behaviour of standard and unknown opals under similar analytical conditions allowed successful determination of ages with precisions of ???10% for the samples investigated in this study. SHRIMP-based U-series and U-Pb ages are consistent with TIMS dating results of the same materials and known geological timeframes. ?? 2005 Elsevier B.V. All rights reserved.

Nemchin, A.A.; Neymark, L.A.; Simons, S.L.

2006-01-01

359

Beneficial effects of Bacillus licheniformis on the intestinal microflora and immunity of the white shrimp, Litopenaeus vannamei.  

PubMed

When Bacillus licheniformis was administered to the white shrimp, Litopenaeus vannamei, although the total bacterial counts in the intestinal tract of the shrimp remained constant, Vibrio numbers significantly decreased (P < 0.05). Haemocyte counts together with phenoloxidase and superoxide dismutase activities of the shrimp were significantly higher (P < 0.05) in treatments than in the control. Thus, administration of B. licheniformis can improve the white shrimp's intestinal microflora and its immune ability. PMID:17333467

Li, Ke; Zheng, Tianling; Tian, Yun; Xi, Feng; Yuan, Jianjun; Zhang, Guozheng; Hong, Huasheng

2007-04-01

360

Shrimps that pay attention: saccadic eye movements in stomatopod crustaceans.  

PubMed

Discovering that a shrimp can flick its eyes over to a fish and follow up by tracking it or flicking back to observe something else implies a 'primate-like' awareness of the immediate environment that we do not normally associate with crustaceans. For several reasons, stomatopods (mantis shrimp) do not fit the general mould of their subphylum, and here we add saccadic, acquisitional eye movements to their repertoire of unusual visual capabilities. Optically, their apposition compound eyes contain an area of heightened acuity, in some ways similar to the fovea of vertebrate eyes. Using rapid eye movements of up to several hundred degrees per second, objects of interest are placed under the scrutiny of this area. While other arthropod species, including insects and spiders, are known to possess and use acute zones in similar saccadic gaze relocations, stomatopods are the only crustacean known with such abilities. Differences among species exist, generally reflecting both the eye size and lifestyle of the animal, with the larger-eyed more sedentary species producing slower saccades than the smaller-eyed, more active species. Possessing the ability to rapidly look at and assess objects is ecologically important for mantis shrimps, as their lifestyle is, by any standards, fast, furious and deadly. PMID:24395969

Marshall, N J; Land, M F; Cronin, T W

2014-01-01

361

Investigation of the fate of trifluralin in shrimp.  

PubMed

Juvenile Pacific white shrimp (Litopenaeus vannamei) were exposed to trifluralin at 0.1 and 0.01 mg L(-1) for 72 h under controlled conditions. Samples of shrimp and tank water were collected at intervals up to 48 days after exposure. Analysis of the shrimp tissues by gas chromatography-mass spectrometry (GC-MS) and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-qToF-MS) in combination with profiling and metabolite identification software (Agilent MET-ID and Mass Profiler Professional) detected the presence of parent trifluralin together with two main transformation products (TPs), 2-ethyl-7-nitro-5-(trifluoromethyl)benzimidazole (TP1) and 2-amino-6-nitro-4-(trifluoromethyl)phenyl)propylamine (TP2). The highest concentration of trifluralin, determined by GC-MS, was 120 ?g kg(-1) at 0 day withdrawal. Residues of trifluralin (CC? = 0.25 ?g kg(-1), CC? = 0.42 ?g kg(-1)) were detectable for up to 7 days after exposure. Similarly, the highest concentrations of TP1 and TP 2, determined by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS), were 14 and 18 ?g kg(-1), respectively. Residues of TP1 (CC? = 0.05 ?g kg(-1), CC? = 0.09 ?g kg(-1)) and TP2 (CC? = 0.1 ?g kg(-1), CC? = 0.17 ?g kg(-1)) were detectable for up to 4 and 24 withdrawal days, respectively. PMID:23339341

Chan, Danny; Fussell, Richard J; Hetmanski, Mike T; Sinclair, Chris J; Kay, Jack F; Grant, Andrew; Sharman, Matthew

2013-03-13

362

Abundance and size of Gulf shrimp in Louisiana's coastal estuaries following the Deepwater Horizon oil spill.  

PubMed

The Deepwater Horizon oil spill impacted Louisiana's coastal estuaries physically, chemically, and biologically. To better understand the ecological consequences of this oil spill on Louisiana estuaries, we compared the abundance and size of two Gulf shrimp species (Farfantepeneus aztecus and Litopeneus setiferus) in heavily affected and relatively unaffected estuaries, before and after the oil spill. Two datasets were used to conduct this study: data on shrimp abundance and size before the spill were available from Louisiana Department of Wildlife and Fisheries (LDWF). Data on shrimp abundance and size from after the spill were independently collected by the authors and by LDWF. Using a Before-After-Control-Impact with Paired sampling (BACIP) design with monthly samples of two selected basins, we found brown shrimp to become more abundant and the mean size of white shrimp to become smaller. Using a BACIP with data on successive shrimp year-classes of multiple basins, we found both species to become more abundant in basins that were affected by the spill, while mean shrimp size either not change after the spill, or increased in both affected and unaffected basins. We conclude that following the oil spill abundances of both species increased within affected estuaries, whereas mean size may have been unaffected. We propose two factors that may have caused these results: 1) exposure to polycyclic aromatic hydrocarbons (PAHs) may have reduced the growth rate of shrimp, resulting in a delayed movement of shrimp to offshore habitats, and an increase of within-estuary shrimp abundance, and 2) fishing closures established immediately after the spill, may have resulted in decreased fishing effort and an increase in shrimp abundance. This study accentuates the complexities in determining ecological effects of oil spills, and the need of studies on the organismal level to reveal cause-and-effect relationships of such events. PMID:25272142

van der Ham, Joris L; de Mutsert, Kim

2014-01-01

363

Reprint of "evolution of specific immunity in shrimp - a vaccination perspective against white spot syndrome virus".  

PubMed

Invertebrates lack true adaptive immunity and it solely depends on the primitive immunity called innate immunity. However, various innate immune molecules and mechanisms are identified in shrimp that plays potential role against invading bacterial, fungal and viral pathogens. Perceiving the shrimp innate immune mechanisms will contribute in developing effective vaccine strategies against major shrimp pathogens. Hence this review intends to explore the innate immune molecules of shrimp with suitable experimental evidences together with the evolution of "specific immune priming" of invertebrates. In addition, we have emphasized on the development of an effective vaccine strategy against major shrimp pathogen, white spot syndrome virus (WSSV). The baculovirus displayed rVP28 (Bac-VP28), a major envelope protein of WSSV was utilized to study its vaccine efficacy by oral route. A significant advantage of this baculovirus expression cassette is the use of WSSV-immediate early 1 (ie1) promoter that derived the abundant expression of rVP28 protein at the early stage of the infection in insect cell. The orally vaccinated shrimp with Bac-VP28 transduced successfully in the shrimp cells as well as provided highest survival rate. In support to our vaccine efficacy we analysed Pattern Recognition Proteins (PRPs) ?-1,3 glucan lipopolysaccharides (LGBP) and STAT gene profiles in the experimental shrimp. Indeed, the vaccination of shrimp with Bac-VP28 demonstrated some degree of specificity with enhanced survival rate when compared to control vaccination with Bac-wt. Hence it is presumed that the concept of "specific immune priming" in relevant to shrimp immunity is possible but may not be common to all shrimp pathogens. PMID:25083808

Syed Musthaq, Syed Khader; Kwang, Jimmy

2015-02-01

364

An Assessment of the Economic Importance of the San Carlos Island Shrimp Processing Industry to the Lee County Economy  

E-print Network

to the Lee County Economy Chuck Adams, David Mulkey, and Alan Hodges Food and Resource Economics Department the shrimp processing industry on San Carlos Island contributes to the Lee County economy. Most of the shrimp of the revenues earned on a trip are spent within the Lee County economy. During seasons when shrimp landings

Florida, University of

365

Infrared Space Observatory Spectra of R Coronae Borealis Stars. I. Emission Features in the Interval 3 - 25 microns  

Microsoft Academic Search

Infrared Space Observatory 3 - 25 $\\\\mu$m spectra of the R Coronae Borealis\\u000astars V854 Cen, R CrB, and RY Sgr are presented and discussed. Sharp emission\\u000afeatures coincident in wavelengths with the well known Unidentified Emission\\u000aFeatures are present in the spectrum of V854 Cen but not of R CrB or RY Sgr.\\u000aSince V854 Cen is not particularly

David L. Lambert; N. Kameswara Rao; Gajendra Pandey; Inese I. Ivans

2001-01-01

366

Feeding biology of the shrimp Rimicaris exoculata at hydrothermal vents on the Mid-Atlantic Ridge  

Microsoft Academic Search

A newly described species of shrimp, Rimicaris exoculata Williams and Rona, 1986, dominates the megafaunal community at two hydrothermal vent sites on the Mid-Atlantic Ridge. Behavioral observations and gut-content analyses indicate, that these shrimp ingest large amounts of sulfide particles from black smoker chimneys. We found no evidence for chemoautotrophic endosymbionts in R. exoculata, based on analyses of morphology, stable

C. L. Dover; B. Fry; J. F. Grassle; S. Humphris; P. A. Rona

1988-01-01

367

ULTRASTRUCTURAL STUDY OF LESIONS IN GILLS OF A MARINE SHRIMP EXPOSED TO CADMIUM  

EPA Science Inventory

Pathologic black gills of pink shrimp, Penaeus duorarum, exposed to 763 micrograms/l of cadmium chloride for 15 days were studied with transmission electron microscopy and were compared with normal gills of control pink shrimp. Local as well as extensive areas of cell death and n...

368

59 FR- Foreign Fishing; Shrimp Fishery of the Gulf of Mexico  

Federal Register 2010, 2011, 2012, 2013

...Fishing; Shrimp Fishery of the Gulf of Mexico AGENCY: National Marine Fisheries...Plan for the Shrimp Fishery of the Gulf of Mexico (FMP). This rule increases the...exclusive economic zone (EEZ) of the Gulf of Mexico and eliminates the total...

1994-12-28

369

59 FR- Foreign Fishing; Shrimp Fishery of the Gulf of Mexico  

Federal Register 2010, 2011, 2012, 2013

...Fishing; Shrimp Fishery of the Gulf of Mexico AGENCY: National Marine Fisheries...Plan for the Shrimp Fishery of the Gulf of Mexico (FMP). This rule would increase...exclusive economic zone (EEZ) of the Gulf of Mexico and would eliminate the total...

1994-09-12

370

BIOACCUMULATION OF KEPONE BY GRASS SHRIMP (PALAEMONETIS PUGIO): IMPORTANCE OF DIETARY ACCUMULATION AND INGESTION RATE  

EPA Science Inventory

The relative extent of dietary accumulation and bioconcentration of Kepone by grass shrimp (Palaemonetes pugio) was quantitatively evaluated at food rations of 4 and of the average wet weight of the shrimp. 14C]Kepone was utilized to determine bioconcentration and dietary accumul...

371

FEEDING RATES OF THE MUD SHRIMP UPOGEBIA PUGETTENSIS AND IMPLICATIONS FOR ESTUARINE PHYTOPLANKTON ABUNDANCE  

EPA Science Inventory

The burrowing shrimp Upogebia pugettensis is an abundant inhabitant of Pacific Northwest bays and estuaries where it lives commensally with the clam Cryptomya californica. Suspension-feeding activities of the shrimp and its commensal clam, as well as particle settlement within t...

372

Assessing Ecological Impacts of Shrimp and Sewage Effluent: Biological Indicators with Standard Water Quality Analyses  

Microsoft Academic Search

Despite evidence linking shrimp farming to several cases of environmental degradation, there remains a lack of ecologically meaningful information about the impacts of effluent on receiving waters. The aim of this study was to determine the biological impact of shrimp farm effluent, and to compare and distinguish its impacts from treated sewage effluent. Analyses included standard water quality\\/sediment parameters, as

A. B. Jones; M. J. O'Donohue; J. Udy; W. C. Dennison

2001-01-01

373

USE OF THE GRASS SHRIMP 'PALAEMONETES PUGIO' IN A LIFE-CYCLE TOXICITY TEST  

EPA Science Inventory

A methodology for using the estuarine grass shrimp (Palaemonetes pugio) in life-cycle toxicity tests was successfully developed. Life-cycle exposures of juvenile shrimp (12 to 19 mm in rostrum-telson length) to the chlorinated hydrocarbon pesticide endrin were begun in November 1...

374

ECOLOGICAL EFFICIENCY OF A PELAGIC MYSID SHRIMP; ESTIMATES FROM GROWTH, ENERGY BUDGET, AND MORTALITY STUDIES'  

E-print Network

in food chains, and numbers of conjunctions in food webs depend on the amount of energy passed through composition, and energy content, we have constructed an energy budget for the pelagic mysid shrimpECOLOGICAL EFFICIENCY OF A PELAGIC MYSID SHRIMP; ESTIMATES FROM GROWTH, ENERGY BUDGET

375

Spectral Sensitivity of Vision and Bioluminescence in the Midwater Shrimp Sergestes similis  

Microsoft Academic Search

In the oceanic midwater environment, many fish, squid, and shrimp use luminescent countershading to remain cryptic to silhouette-scanning predators. The mid- water penaeid shrimp, Sergestes similis Hansen, responds to downward-directed light with a dim bioluminescence that dynamically matches the spectral radiance of oceanic down- welling light at depth. Although the sensory basis of lumi- nescent countershading behavior is visual, the

S. M. LINDSAY; T. M. FRANK; J. KENT; J. C. PARTRIDGE; M. I. LATZ

376

Little Shrimp, Big Results: A Model of an Integrative, Cross-Curricular Activity  

ERIC Educational Resources Information Center

This integrative, cross-curricular lab engages middle school biology students in an exercise involving ecology, arthropod biology, and mathematics. Students research the anatomy and behavioral patterns of a species of brine shrimp, compare the anatomy of adult and juvenile brine shrimp, and graph and interpret results. In this article, the authors…

Ackerson, Nicole; Piser, Carol; Walka, Keith

2010-01-01

377

Genetic diversity of wild and cultured Black Tiger Shrimp ( Penaeus monodon) in the Philippines using microsatellites  

Microsoft Academic Search

Six microsatellites were used to study (1) the genetic diversity of wild Penaeus monodon shrimp from four geographic regions (Palawan, Quezon, Capiz and Negros Occidental-W) in the Philippines, and (2) its association with the status of mangroves and intensity of shrimp culture systems in these regions. Two cultured populations (Negros Occidental-C and Antique) were used for comparison. All six microsatellite

Zhenkang Xu; Jurgenne H Primavera; Leobert D de la Pena; Priscilla Pettit; Jane Belak; Acacia Alcivar-Warren

2001-01-01

378

Comparing the efficiency of chitosan with chlorine for reducing Vibrio parahaemolyticus in shrimp  

Microsoft Academic Search

Thailand is one of the leading exporters of frozen shrimp to many countries. Chlorine is the decontaminating agent most frequently used in the frozen shrimp industries to kill potential pathogens. However, long time contact to chlorine causes severe respiratory tract damage. In this study, chitosan was compared to chlorine for reducing Vibrio parahaemolyticus. In vitro investigation, chitosan could reduce more

S. Chaiyakosa; W. Charernjiratragul; K. Umsakul; V. Vuddhakul

2007-01-01

379

Effect of gamma-irradiation on frozen shrimps for decontamination of pathogenic bacteria  

NASA Astrophysics Data System (ADS)

Twelve samples of imported frozen shrimps were used in this study. The total aerobic bacteria were at 2 × 10 4 to 6 × 10 6 per gram. A few of Vibrio parahaemolyticus, V. mimicus, V. alginolyticus, V. vulnificus, V. fluvialis and Listeria monocytogenes were isolated from many samples. However, Salmonella was not detected in any of the samples. After exposure to 4-5 kGy of gamma-rays, the total aerobic bacteria in frozen shrimps were reduced by approximately 2-3 log cycles. The dose necessary to reduce the vibrio isolates and Aeromonas hydrophila at a level of below 10 -4 per gram was about 3 kGy in frozen shrimps, whereas about 3.5 kGy was required for L. monocytogenes and Salmonella typhimurium. In this study, unpleasant off-odor was clearly detected in the non-frozen shrimps irradiated at 2.5 kGy. On the other hand, off-odor was negligible in the frozen product below 5 kGy irradiation. No remarkable changes of peroxide values were also obtained up to 9 kGy of irradiation in the frozen shrimps. However peroxide values of non-frozen shrimps were clearly increased even irradiated at 4 kGy. Trimethylamine content was not changed at doses below 10 kGy in both of frozen and non-frozen shrimps. Shelf-life of defrosted shrimps were extended ca. 2 times under non-frozen market conditions.

Ito, Hitoshi; Rashid, Harun Or; Sangthong, Naruemon; Adulyatham, Pitaya; Rattagool, Pongpen; Ishigaki, Isao

1993-07-01

380

Effect of cryogenic freezing on salmonella and listeria recovery from inoculated shrimp  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the United States, shrimp is number one in seafood consumption. Shrimp is usually imported frozen, and the Food and Drug Administration has isolated Salmonella spp. from this frozen product. This research was conducted to determine the effect of two cryogenic freezing protocols (time and tempe...

381

The American brine shrimp as an exotic invasive species in the western Mediterranean  

Microsoft Academic Search

The hypersaline environments and salterns present in the western Mediterranean region (including Italy, southern France, the\\u000a Iberian Peninsula and Morocco) contain autochthonous forms of the brine shrimp Artemia, with parthenogenetic diploid and tetraploid strains coexisting with the bisexual species A. salina. Introduced populations of the American brine shrimp A. franciscana have also been recorded in these Mediterranean environments since the

Francisco Amat; Francisco Hontoria; Olga Ruiz; Andy J. Green; Marta I. Sánchez; Jordi Figuerola; Francisco Hortas

2005-01-01

382

Immunity enhancement in black tiger shrimp ( Penaeus monodon) by a probiont bacterium ( Bacillus S11)  

Microsoft Academic Search

Survival and growth of Penaeus monodon fed the probiont Bacillus S11 in two 90-day culture trials were increased compared with non-treated shrimp. Bacillus S11 also efficiently activated and increased the engulfment of foreign particles (phagocytic activity) as measured by % phagocytosis and phagocytic index (PI) in hemolymph. Phenoloxidase and antibacterial activities increased with age in all shrimp, but were even

Sirirat Rengpipat; Sombat Rukpratanporn; Somkiat Piyatiratitivorakul; Piamsak Menasaveta

2000-01-01

383

Ex-situ bioremediation of shrimp culture effluent using constructed microbial mats  

Microsoft Academic Search

In coastal countries, marine shrimp industry poses a problem with respect to the waste effluent disposal into the ocean as well as the nearby area. Constructed microbial mats offer an interesting alternative for shrimp culture effluents. The treatment concept relies on the immobilization of natural marine microbial consortium on glass wool to mitigate the levels of dissolved nitrogen from a

J. Paniagua-Michel; O. Garcia

2003-01-01

384

76 FR 12025 - Certain Frozen Warmwater Shrimp From India: Preliminary Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

The Department of Commerce (Department) is conducting an administrative review of the antidumping duty order on certain frozen warmwater shrimp (shrimp) from India with respect to 202 companies.\\1\\ The respondents which the Department selected for individual examination are Apex Exports (Apex) and Falcon Marine Exports Limited (Falcon). The respondents which were not selected for individual......

2011-03-04

385

METHOD OF DETERMINING CAROTENOID CONTENTS OF ALASKA PINK SHRIMP AND REPRESENTATIVE VALVES FOR  

E-print Network

of the proper ace- tone solution: 1. 75 % acetone for canned shrimp with liquor. 2. 65% acetone for frozen cooked or raw meats. 3. 50 % acetone for raw shrimp with shells on. The silica gel, which serves until dripping ceases. Rinse container and filter as needed with 50% acetone. Discard colorless filtrate

386

Hydraulic activities by ghost shrimp Neotrypaea californiensis induce oxic-anoxic oscillations in sediments  

EPA Science Inventory

We applied porewater pressure sensing, time-lapse photography and planar optode imaging of oxygen to investigate hydraulic behaviors of the Thalassinidean ghost shrimp Neotrypaea californiensis and the associated dynamics of oxygen in and around their burrows. Ghost shrimp were h...

387

76 FR 12054 - Certain Frozen Warmwater Shrimp From the Socialist Republic of Vietnam: Preliminary Results...  

Federal Register 2010, 2011, 2012, 2013

...subject merchandise and the raw shrimp input are both sold...reported per-unit factor- consumption rates by publicly available...which to value the main input, raw shrimp. Domestic Producers...withdrawn from warehouse, for consumption on or after the...

2011-03-04

388

78 FR 50389 - Certain Frozen Warmwater Shrimp From Ecuador: Final Affirmative Countervailing Duty Determination  

Federal Register 2010, 2011, 2012, 2013

...Export Restraints on Raw and Unprocessed Shrimp...withdrawn from warehouse, for consumption on or after the date of...not deveined, cooked or raw, or otherwise processed...containing egg and/or milk, and par-fried. The...Export Restraints on Raw, Unprocessed Shrimp...

2013-08-19

389

Competition in phenotypically variable and uniform populations of the tadpole shrimp Triops longicaudatus (Notostraca: Triopsidae)  

Microsoft Academic Search

Life-history parameters (growth, reproduction, and survival) were measured from one genetically heterogeneous and three homogeneous populations of tadpole shrimp (Triops longicaudatus) raised under three competitive levels: 5, 10, and 16 shrimp per 38-1 aquarium. Comparisons were made between the homogeneous populations (three monomorphic selfing lines) and a heterogeneous population (a mixture of the three lines) to test for increased productivity

Clay Sassaman

1990-01-01

390

Velocity Measurements of a Pistol Shrimp's Micro Water Jet Using High Speed PIV  

Microsoft Academic Search

The pistol shrimp generates a high speed micro water jet that was studied experimentally using time resolved particle image velocimetry. The pistol shrimp, with an average size of about 5.5 cm, is considered to be one of the loudest animals in the world. The sound generated can reach intensity levels as high as 200 db. In the past, it was

J. Torres; S. Wong; M. Zarzecki; Y. Cheng; F. J. Diez

2007-01-01

391

Effect of peach gum polysaccharides on quality changes of white shrimp.  

PubMed

Peach gum polysaccharides (PGPs) have both antibacterial and antioxidant activities. In this study, the retardation effect of the PGPs on the quality changes of white shrimp (Penaeus vannamei) during refrigerated storage was investigated. Shrimp samples were untreated with different concentrations of the PGPs solution and then they were stored under refrigerated conditions for 10 days. During refrigerated storage, shrimp samples were taken periodically and their total viable count, pH value, total volatile basic nitrogen, and overall acceptability score were evaluated. Compared to the control, treatment of the PGPs solution effectively retarded bacterial growth and pH changes, reduced total volatile basic nitrogen, and increased overall acceptability score of white shrimp (P. vannamei) during refrigerated storage. The results indicate that treatment of PGPs could be a promising means to preserve white shrimp (P. vannamei). PMID:25450827

Yao, Xing-Cun; Chang, Cheng-Fei; Wu, Sheng-Jun

2015-01-01

392

Predation by dipteran larvae on fairy shrimp (Crustacea: Anostraca) in Utah rock pools  

USGS Publications Warehouse

A series of experiments examined how ecological factors affect notonectid foraging success on fairy shrimp. Variation in pond depth over natural ranges had no direct effect on notonectid ability to capture fairy shrimp. Decreases in water clarity over natural ranges led to decreased notonectid ability to capture fairy shrimp. This corresponds with the observation that six weeks after the fairy shrimp hatched they were more likely to be present in cloudy ponds than in ponds containing clearer water. If correct, this is a situation where physical factors have a major effect on how a biological interaction influences the local distribution of species. It appears water depth indirectly affects notonectid foraging rates, as shallow ponds are apparently made cloudy by wind-driven waves disturbing the bottom mud. These results suggest the notonectid-fairy shrimp interaction will not be a constant for any given pond, but will depend on abiotic factors like amount of rainfall and frequency of windy conditions.

Graham, T.B.

1994-01-01

393

Scanning electron microscope observations of brine shrimp larvae from space shuttle experiments  

NASA Technical Reports Server (NTRS)

Brine shrimp are encysted as gastrula stage embryos, and may remain dehydrated and encysted for years without compromising their viability. This aspect of brine shrimp biology is desirable for studying development of animals during space shuttle flight, as cysts placed aboard a spacecraft may be rehydrated at the convenience of an astronaut, guaranteeing that subsequent brine shrimp development occurs only on orbit and not on the pad during launch delays. Brine shrimp cysts placed in 5 ml syringes were rehydrated with salt water and hatched during a 9 day space shuttle mission. Subsequent larvae developed to the 8th larval stage in the sealed syringes. We studied the morphogenesis of the brine shrimp larvae and found the larvae from the space shuttle experiments similar in rate of growth and extent of development, to larvae grown in sealed syringes on the ground. Extensive differentiation and development of embryos and larvae can occur in a microgravity environment.

DeBell, L.; Paulsen, A.; Spooner, B.

1992-01-01

394

Evaluate of heavy metal concentration in shrimp (Penaeus semisulcatus) and crab (Portunus pelagicus) with INAA method.  

PubMed

The level of the heavy metal in green tiger shrimp (Penaeus semisulcatus) and crab (Portunus pelagicus) caught off the Persian Gulf near Bushehr province were investigated. This study was performed to evaluate instrumental neutron activation analysis (INAA) to analyze heavy metal concentration in crab and shrimp whole body tissue. The order of the swimmer crab and shrimp heavy metal concentrations were Zn>Fe>As>Mn>Co and Fe>Zn>Mn>As>Co, respectively. The results showed swimmer crab (Portunus pelagicus) and shrimp (Penaeus semisulcatus) caught off Persian gulf, were contaminated with high level of As (21.38±3.31ppm and 8.28±2.82 ppm, respectively). High levels of As and Mn were noted in crabs and shrimp, respectively. PMID:23487484

Heidarieh, Marzieh; Maragheh, Mohammad Ghannadi; Shamami, Mehrdad Azizi; Behgar, Mehdi; Ziaei, Farhood; Akbari, Zahra

2013-12-01

395

Observations of the Corona Borealis supercluster with the superextended Very Small Array: further constraints on the nature of the non-Gaussian cosmic microwave background cold spot  

Microsoft Academic Search

We present interferometric imaging at 33GHz, with the new superextended configuration of the Very Small Array (VSA), of a very deep decrement in the cosmic microwave background (CMB) temperature. This decrement is located in the direction of the Corona Borealis supercluster, at a position with no known galaxy clusters, and was discovered by a previous VSA survey. A total area

Ricardo Génova-Santos; José Alberto Rubiño-Martín; Rafael Rebolo; Richard A. Battye; Francisco Blanco; Rod D. Davies; Richard J. Davis; Thomas Franzen; Keith Grainge; Michael P. Hobson; Anthony Lasenby; Carmen P. Padilla-Torres; Guy G. Pooley; Richard D. E. Saunders; Anna Scaife; Paul F. Scott; David Titterington; Marco Tucci; Robert A. Watson

2008-01-01

396

DISCOVERY OF BRIGHT GALACTIC R CORONAE BOREALIS AND DY PERSEI VARIABLES: RARE GEMS MINED FROM ACVS  

SciTech Connect

We present the results of a machine-learning (ML)-based search for new R Coronae Borealis (RCB) stars and DY Persei-like stars (DYPers) in the Galaxy using cataloged light curves from the All-Sky Automated Survey (ASAS) Catalog of Variable Stars (ACVS). RCB stars-a rare class of hydrogen-deficient carbon-rich supergiants-are of great interest owing to the insights they can provide on the late stages of stellar evolution. DYPers are possibly the low-temperature, low-luminosity analogs to the RCB phenomenon, though additional examples are needed to fully establish this connection. While RCB stars and DYPers are traditionally identified by epochs of extreme dimming that occur without regularity, the ML search framework more fully captures the richness and diversity of their photometric behavior. We demonstrate that our ML method can use newly discovered RCB stars to identify additional candidates within the same data set. Our search yields 15 candidates that we consider likely RCB stars/DYPers: new spectroscopic observations confirm that four of these candidates are RCB stars and four are DYPers. Our discovery of four new DYPers increases the number of known Galactic DYPers from two to six; noteworthy is that one of the new DYPers has a measured parallax and is m Almost-Equal-To 7 mag, making it the brightest known DYPer to date. Future observations of these new DYPers should prove instrumental in establishing the RCB connection. We consider these results, derived from a machine-learned probabilistic classification catalog, as an important proof-of-concept for the efficient discovery of rare sources with time-domain surveys.

Miller, A. A.; Richards, J. W.; Bloom, J. S.; Cenko, S. B.; Silverman, J. M.; Starr, D. L. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Stassun, K. G., E-mail: amiller@astro.berkeley.edu [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States)

2012-08-20

397

The Corona Borealis Supercluster - I: Observational Analysis of the Inter-Cluster Dynamics  

NASA Astrophysics Data System (ADS)

We present the results of a dynamical analysis of the core of the Corona Borealis Supercluster (CSC), a highly dense and compact supercluster at z ? 0.07. Expanding on work presented in a recent paper (Batiste & Batuski, 2013), we use data from the Sloan Digital Sky Survey to assess the current dynamical state of the core of the CSC. The Fundamental Plane relation for early-type galaxies is used to determine redshift independent distances to seven clusters in the densest portion of the CSC, with mean accuracy in the relative distance estimates of 4%. Peculiar velocities for each of the seven clusters, determined using these distance estimates, indicate significant extended bound structure in the CSC. We find evidence for two collapsing regions, with some indication that these regions are not dynamically isolated but are in fact bound to each other. Comparing our results with simulations of the core of the CSC (Pearson & Batuski, 2013), we find that significantly more mass is required to bind the structure than is present in the clusters, suggesting a large inter-cluster matter component. We assess the likelihood that this additional mass could be accounted for by field galaxies, and investigate the possibility of an inter-cluster dark matter component as an explanation of our observations. Comparison of the observational analysis with these simulations suggests that the two bound regions identified in our analysis are likely bound to each other, and that the core of the CSC consists of at least five clusters, and has likely reached turnaround and is in collapse.

Batiste, Merida; Pearson, D.; Batuski, D. J.

2014-01-01

398

Detection of Near-Infrared CO Absorption Bands in R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

R Coronae Borealis (RCB) stars are hydrogen-deficient, carbon-rich, pulsating, post-asymptotic giant branch stars that experience massive irregular declines in brightness caused by circumstellar dust formation. The mechanism of dust formation around RCB stars is not well understood. It has been proposed that CO molecules play an important role in cooling the circumstellar gas so that dust may form. We report on a survey for CO in a sample of RCB stars. We obtained H- and K-band spectra including the first- and second-overtone CO bands for eight RCB stars, the RCB-like star DY Per, and the final-helium-flash star FG Sge. The first- and second-overtone CO bands were detected in the cooler (Teff<6000 K) RCB stars, Z Umi, ES Aql, SV Sge, and DY Per. The bands are not present in the warmer (Teff>6000 K) RCB stars, R CrB, RY Sgr, SU Tau, and XX Cam. In addition, first-overtone bands are seen in FG Sge, a final-helium-flash star that is in an RCB-like phase at present. Effective temperatures of the eight RCB stars range from 4000 to 7250 K. The observed photospheric CO absorption bands were compared to line-blanketed model spectra of RCB stars. As predicted by the models, the CO bands are strongest in the coolest RCB stars and not present in the warmest. No correlation was found between the presence or strength of the CO bands and dust formation activity in the stars.

Tenenbaum, Emily D.; Clayton, Geoffrey C.; Asplund, Martin; Engelbracht, C. W.; Gordon, Karl D.; Hanson, M. M.; Rudy, Richard J.; Lynch, David K.; Mazuk, S.; Venturini, Catherine C.; Puetter, R. C.

2005-07-01

399

A VSA search for the extended Sunyaev-Zel'dovich Effect in the Corona Borealis Supercluster  

E-print Network

We present interferometric imaging at 33 GHz of the Corona Borealis supercluster, using the extended configuration of the Very Small Array. A total area of 24 deg^2 has been imaged, with an angular resolution of 11 arcmin and a sensitivity of 12 mJy/beam. The aim of these observations is to search for Sunyaev-Zel'dovich (SZ) detections from known clusters of galaxies in this supercluster and for a possible extended SZ decrement due to diffuse warm/hot gas in the intercluster medium. We measure negative flux values in the positions of the ten richest clusters in the region. Collectively, this implies a 3.0-sigma detection of the SZ effect. In the clusters A2061 and A2065 we find decrements of approximately 2-sigma. Our main result is the detection of two strong and resolved negative features at -70+-12 mJy/beam (-157+-27 microK) and -103+-10 mJy/beam (-230+-23 microK), respectively, located in a region with no known clusters, near the centre of the supercluster. We discuss their possible origins in terms of primordial CMB anisotropies and/or SZ signals related to either unknown clusters or to a diffuse extended warm/hot gas distribution. Our analyses have revealed that a primordial CMB fluctuation is a plausible explanation for the weaker feature (probability of 37.82%). For the stronger one, neither primordial CMB (probability of 0.33%) nor SZ can account alone for its size and total intensity. The most reasonable explanation, then, is a combination of both primordial CMB and SZ signal. Finally, we explore what characteristics would be required for a filamentary structure consisting of warm/hot diffuse gas in order to produce a significant contribution to such a spot taking into account the constraints set by X-ray data.

Ricardo Genova-Santos; Jose Alberto Rubino-Martin; Rafael Rebolo; Kieran Cleary; Rod D. Davies; Richard J. Davis; Clive Dickinson; Nelson Falcon; Keith Grainge; Carlos M. Gutierrez; Michael P. Hobson; Michael E. Jones; Ruediger Kneissl; Katy Lancaster; Carmen P. Padilla-Torres; Richard D. E. Saunders; Paul F. Scott; Angela C. Taylor; Robert A. Watson

2005-07-12

400

Dust around R Coronae Borealis Stars. I. Spitzer/Infrared Spectrograph Observations  

NASA Astrophysics Data System (ADS)

Spitzer/infrared spectrograph (IRS) spectra from 5 to 37 ?m for a complete sample of 31 R Coronae Borealis stars (RCBs) are presented. These spectra are combined with optical and near-infrared photometry of each RCB at maximum light to compile a spectral energy distribution (SED). The SEDs are fitted with blackbody flux distributions and estimates are made of the ratio of the infrared flux from circumstellar dust to the flux emitted by the star. Comparisons for 29 of the 31 stars are made with the Infrared Astronomical Satellite (IRAS) fluxes from three decades earlier: Spitzer and IRAS fluxes at 12 ?m and 25 ?m are essentially equal for all but a minority of the sample. For this minority, the IRAS to Spitzer flux ratio exceeds a factor of three. The outliers are suggested to be stars where formation of a dust cloud or dust puff is a rare event. A single puff ejected prior to the IRAS observations may have been reobserved by Spitzer as a cooler puff at a greater distance from the RCB. RCBs which experience more frequent optical declines have, in general, a circumstellar environment containing puffs subtending a larger solid angle at the star and a quasi-constant infrared flux. Yet, the estimated subtended solid angles and the blackbody temperatures of the dust show a systematic evolution to lower solid angles and cooler temperatures in the interval between IRAS and Spitzer. Dust emission by these RCBs and those in the LMC is similar in terms of total 24 ?m luminosity and [8.0]-[24.0] color index.

García-Hernández, D. A.; Kameswara Rao, N.; Lambert, David L.

2011-09-01

401

R Coronae Borealis stars in the Galactic Bulge discovered by EROS-2  

E-print Network

Rare types of variable star may give unique insight into short-lived stages of stellar evolution. The systematic monitoring of millions of stars and advanced light curve analysis techniques of microlensing surveys make them ideal for discovering also such rare variable stars. One example is the R Coronae Borealis (RCB) stars, a rare type of evolved carbon-rich supergiant. We have conducted a systematic search of the EROS-2 database for the Galactic catalogue Bulge and spiral arms to find Galactic RCB stars. The light curves of $\\sim$100 million stars, monitored for 6.7 years (from July 1996 to February 2003), have been analysed to search for the main signature of RCB stars, large and rapid drops in luminosity. Follow-up spectroscopy has been used to confirm the photometric candidates. We have discovered 14 new RCB stars, all in the direction of the Galactic Bulge, bringing the total number of confirmed Galactic RCB stars to about 51. After reddening correction, the colours and absolute magnitudes of at least 9 of the stars are similar to those of Magellanic RCB stars. This suggests that these stars are in fact located in the Galactic Bulge, making them the first RCB stars discovered in the Bulge. The localisation of the 5 remaining RCBs is more uncertain: 4 are either located behind the Bulge at an estimated maximum distance of 14 kpc or have an unusual thick circumstellar shell; the other is a DY Per RCB which may be located in the Bulge, even if it is fainter than the known Magellanic DY Per. From the small scale height found using the 9 new Bulge RCBs, $61

P. Tisserand; J. B. Marquette; P. R. Wood; E. Lesquoy; J. P. Beaulieu; A. Milsztajn; C. Hamadache; C. Afonso; J. N. Albert; J. Andersen; R. Ansari; E. Aubourg; P. Bareyre; X. Charlot; C. Coutures; R. Ferlet; P. Fouqué; J. F. Glicenstein; B. Goldman; A. Gould; M. Gros; J. Haissinski; J. de Kat; L. Le Guillou; C. Loup; C. Magneville; E. Maurice; A. Maury; M. Moniez; N. Palanque-Delabrouille; O. Perdereau; Y. Rahal; J. Rich; M. Spiro; A. Vidal-Madjar; S. Zylberajch

2008-01-11

402

An XMM-Newton Study of the Coronae of $?^2$ Coronae Borealis  

E-print Network

(Abridged) We present results of XMM-Newton observations of the RS CVn binary $\\sigma^2$ Coronae Borealis. The RGS and EPIC MOS2 spectra were simultaneously fitted with collisional ionization equilibrium plasma models to determine coronal abundances of various elements. Contrary to the solar first ionization potential (FIP) effect in which elements with a low FIP are overabundant in the corona compared to the solar photosphere, and contrary to the ``inverse'' FIP effect observed in several active RS CVn binaries, coronal abundance ratios in $\\sigma^2$ CrB show a complex pattern as supported by similar findings in the Chandra HETGS analysis of $\\sigma^2$ CrB with a different methodology (Osten et al. 2003). Low-FIP elements ($<10$ eV) have their abundance ratios relative to Fe consistent with the solar photospheric ratios, whereas high-FIP elements have their abundance ratios increase with increasing FIP. We find that the coronal Fe abundance is consistent with the stellar photospheric value, indicating that there is no metal depletion in $\\sigma^2$ CrB. However, we obtain a higher Fe absolute abundance than in Osten et al. (2003). Except for Ar and S, our absolute abundances are about 1.5 times larger than those reported by Osten et al. (2003). However, a comparison of their model with our XMM-Newton data (and vice versa) shows that both models work adequately in general. We find, therefore, no preference for one methodology over the other to derive coronal abundances. Despite the systematic discrepancy in absolute abundances, our abundance ratios are very close to those obtained by Osten et al. (2003). Finally, we confirm the measurement of a low density in \\ion{O}{7} ($< 4 \\times 10^{10}$ cm$^{-3}$), but could not confirm the higher densities measured in spectral lines formed at higher temperatures.

J. A. Suh; M. Audard; M. Guedel; F. B. S. Paerels

2005-06-10

403

Discovery of Bright Galactic R Coronae Borealis and DY Persei Variables: Rare Gems Mined from ACVS  

NASA Astrophysics Data System (ADS)

We present the results of a machine-learning (ML)-based search for new R Coronae Borealis (RCB) stars and DY Persei-like stars (DYPers) in the Galaxy using cataloged light curves from the All-Sky Automated Survey (ASAS) Catalog of Variable Stars (ACVS). RCB stars—a rare class of hydrogen-deficient carbon-rich supergiants—are of great interest owing to the insights they can provide on the late stages of stellar evolution. DYPers are possibly the low-temperature, low-luminosity analogs to the RCB phenomenon, though additional examples are needed to fully establish this connection. While RCB stars and DYPers are traditionally identified by epochs of extreme dimming that occur without regularity, the ML search framework more fully captures the richness and diversity of their photometric behavior. We demonstrate that our ML method can use newly discovered RCB stars to identify additional candidates within the same data set. Our search yields 15 candidates that we consider likely RCB stars/DYPers: new spectroscopic observations confirm that four of these candidates are RCB stars and four are DYPers. Our discovery of four new DYPers increases the number of known Galactic DYPers from two to six; noteworthy is that one of the new DYPers has a measured parallax and is m ? 7 mag, making it the brightest known DYPer to date. Future observations of these new DYPers should prove instrumental in establishing the RCB connection. We consider these results, derived from a machine-learned probabilistic classification catalog, as an important proof-of-concept for the efficient discovery of rare sources with time-domain surveys.

Miller, A. A.; Richards, J. W.; Bloom, J. S.; Cenko, S. B.; Silverman, J. M.; Starr, D. L.; Stassun, K. G.

2012-08-01

404

The R Coronae Borealis stars - carbon abundances from forbidden carbon lines  

E-print Network

Spectra of several R Coronae Borealis (RCB) stars at maximum light were examined for the [C I] 9850 A and 8727 A absorption lines. The 9850 A line is variously blended with a Fe II and CN lines but positive identifications of the [C I] line are made for R CrB and SU Tau. The 8727 A line is detected in the spectrum of the five stars observed in this wavelength region. Carbon abundances are derived from the [C I] lines using the model atmospheres and atmospheric parameters used by Asplund et al. (2000). Although the observed strength of a C I line is constant from cool to hot RCB stars, the strength is weaker than predicted by an amount equivalent to a factor of four reduction of a line's gf-value. Asplund et al. dubbed this 'the carbon problem' and discussed possible solutions. The [C I] 9850 A line seen clearly in R CrB and SU Tau confirms the magnitude of the carbon problem revealed by the C I lines. The [C I] 8727 A line measured in five stars shows an enhanced carbon problem. The gf-value required to fit the observed [C I] 8727 A line is a factor of 15 less than the well-determined theoretical gf-value. We suggest that the carbon problem for all lines may be alleviated to some extent by a chromospheric-like temperature rise in these stars. The rise far exceeds that predicted by our non-LTE calculations, and requires a substantial deposition of mechanical energy.

Gajendra Pandey; David L. Lambert; N. Kameswara Rao; Bengt Gustafsson; Nils Ryde; David Yong

2004-05-29

405

Using 16O/18O to Determine the Evolutionary History of the R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

All of the Galactic hydrogen-deficient carbon (HdC) and R Coronae Borealis (RCB) stars for which oxygen isotopic ratios can be measured, show 16O/18O < 5, values that are orders of magnitude lower than measured in other stars (the Solar value is 500). This suggests that most if not all HdC and RCB stars are highly enriched in 18O. This is an important clue to determining the evolutionary pathways of HdC and RCB stars, for which two models have been proposed: the double degenerate (white dwarf (WD) merger), and the final helium-shell flash (FF). No overproduction of 18O is expected in the FF scenario. However, some RCB stars also show characteristics, such as 13C and Lithium, seen in FF stars. Therefore, we are conducting a survey of all the RCB stars in the LMC and SMC for the characteristics of a WD merger or a FF. Most of the stars have been surveyed for 13C already, and we are also planning to survey them for Lithium. But no RCB star in the Magellanic Clouds has been observed for 18O. The Magellanic Clouds provide an unbiased, relatively complete sample of RCB stars which are at a known distance so their bolometric luminosities can be used in our stellar evolution models. This proposal is to use Gemini/Flamingos-2 to survey all of the Magellanic Cloud stars, which are cool enough to show CO bands, for the presence of 18O near 2.3 micron. This survey, combined with our stellar evolution models, will reveal the true fraction of RCB stars formed by each of the proposed scenarios.

Clayton, Geoffrey; Geballe, Tom; Welch, Douglas; Tisserand, Patrick

2014-08-01

406

Do R Coronae Borealis Stars Form from Double White Dwarf Mergers?  

NASA Astrophysics Data System (ADS)

A leading formation scenario for R Coronae Borealis (RCB) stars invokes the merger of degenerate He and CO white dwarfs (WDs) in a binary. The observed ratio of 16O/18O for RCB stars is in the range of 0.3-20 much smaller than the solar value of ~500. In this paper, we investigate whether such a low ratio can be obtained in simulations of the merger of a CO and a He WD. We present the results of five three-dimensional hydrodynamic simulations of the merger of a double WD system where the total mass is 0.9 M ? and the initial mass ratio (q) varies between 0.5 and 0.99. We identify in simulations with q <~ 0.7 a feature around the merged stars where the temperatures and densities are suitable for forming 18O. However, more 16O is being dredged up from the C- and O-rich accretor during the merger than the amount of 18O that is produced. Therefore, on the dynamical timescale over which our hydrodynamics simulation runs, an 16O/18O ratio of ~2000 in the "best" case is found. If the conditions found in the hydrodynamic simulations persist for 106 s the oxygen ratio drops to 16 in one case studied, while in a hundred years it drops to ~4 in another case studied, consistent with the observed values in RCB stars. Therefore, the merger of two WDs remains a strong candidate for the formation of these enigmatic stars.

Staff, Jan. E.; Menon, Athira; Herwig, Falk; Even, Wesley; Fryer, Chris L.; Motl, Patrick M.; Geballe, Tom; Pignatari, Marco; Clayton, Geoffrey C.; Tohline, Joel E.

2012-09-01

407

Using 16O/18O to Determine the Evolutionary History of the R Coronae Borealis Stars  

NASA Astrophysics Data System (ADS)

Of the Galactic hydrogen-deficient carbon (HdC) and R Coronae Borealis (RCB) stars for which oxygen isotopic ratios can be measured, all of them show 16O/18O < 5, values that are orders of magnitude lower than measured in other stars (the Solar value is 500). This suggests that most if not all HdC and RCB stars are highly enriched in 18O. This is an important clue in determining the evolutionary pathways of HdC and RCB stars, for which two models have been proposed: the double degenerate (white dwarf (WD) merger), and the final helium-shell flash (FF). No overproduction of 18O is expected in the FF scenario. However, some RCB stars also show characteristics, such as 13C and Lithium, seen in FF stars. Therefore, we are conducting a survey all the RCB stars in the LMC and SMC for the characteristics of a WD merger or a FF. Most of the stars have been surveyed for 13C already and we plan to survey them for Lithium in the future. This proposal is to use Gemini/Flamingos-2 to survey all the stars, which are cool enough to show CO bands, for the presence of 18O near 2.3 micron. The Magellanic Clouds provide an unbiased, relatively complete sample of RCB stars which are at a known distance so their bolometric luminosities can be used in our stellar evolution models. This survey, combined with our models, will reveal the true fraction of RCB stars formed by each of the proposed scenarios.

Clayton, Geoffrey; Geballe, Tom; Welch, Douglas; Tisserand, Patrick

2013-08-01

408

Effects of southern flying squirrels Glaucomys volans on red-cockaded woodpecker Picoides borealis reproductive success  

USGS Publications Warehouse

Anecdotal data gathered from many populations suggest that southern flying squirrel (SFS, Glaucomys volans) use of the endangered red-cockaded woodpecker's (RCW, Picoides borealis) nest and roost cavities may negatively affect RCW populations. We conducted a controlled experiment to determine the effects of SFSs on RCW reproductive success. During the 1994 and 1995 breeding seasons, SFSs were removed from 30 RCW clusters and 32 clusters served as controls. SFSs were the most frequently encountered occupants of RCW cavities and used 20-33% of RCW cavities in control and treatment clusters over both years. Treatment groups produced significantly more successful nests (??? 1 fledgling) than control groups in 1994. In 1995 however, there was no difference in the number of successful nests. In both years, RCW groups nesting in treatment clusters produced significantly more fledglings than groups in control clusters in each of four experimental areas, averaging approximately 0.7 additional fledglings per nesting group. Loss of entire clutches or broods, possibly as a result of predation or abandonment, was a major factor limiting reproduction in control groups in 1994. In contrast, differences in partial brood loss appeared to be the cause of differential fledging success in 1995 Usurpation of RCW roost cavities by SFSs may have placed greater energetic demands on RCWs for cavity defence or thermoregulation, thus reducing energy available for reproduction. Our results show that SFS use of RCW cavities during the breeding season has a significant impact on RCWs and that management of RCW populations should include activities that either minimize SFS populations in RCW clusters or limit access of SFSs to RCW cavities.

Laves, K.S.; Loeb, S.C.

1999-01-01

409

DUST AROUND R CORONAE BOREALIS STARS. II. INFRARED EMISSION FEATURES IN AN H-POOR ENVIRONMENT  

SciTech Connect

Residual Spitzer/Infrared Spectrograph spectra for a sample of 31 R Coronae Borealis (RCB) stars are presented and discussed in terms of narrow emission features superimposed on the quasi-blackbody continuous infrared emission. A broad {approx}6-10 {mu}m dust emission complex is seen in the RCBs showing an extreme H-deficiency. A secondary and much weaker {approx}11.5-15 {mu}m broad emission feature is detected in a few RCBs with the strongest {approx}6-10 {mu}m dust complex. The Spitzer infrared spectra reveal for the first time the structure within the {approx}6-10 {mu}m dust complex, showing the presence of strong C-C stretching modes at {approx}6.3 and 8.1 {mu}m as well as of other dust features at {approx}5.9, 6.9, and 7.3 {mu}m, which are attributable to amorphous carbonaceous solids with little or no hydrogen. The few RCBs with only moderate H-deficiencies display the classical ''unidentified infrared bands (UIRs)'' and mid-infrared features from fullerene-related molecules. In general, the characteristics of the RCB infrared emission features are not correlated with the stellar and circumstellar properties, suggesting that the RCB dust features may not be dependent on the present physical conditions around RCB stars. The only exception seems to be the central wavelength of the 6.3 {mu}m feature, which is blueshifted in those RCBs showing also the UIRs, i.e., the RCBs with the smallest H deficiency.

Garcia-Hernandez, D. A. [Instituto de Astrofisica de Canarias, C/Via Lactea s/n, E-38200 La Laguna (Spain); Rao, N. Kameswara [543, 17th Main, IV Sector, HSR Layout, Bangalore 560102 and Indian Institute of Astrophysics, Bangalore 560034 (India); Lambert, D. L., E-mail: agarcia@iac.es, E-mail: nkrao@iiap.res.in, E-mail: dll@astro.as.utexas.edu [W. J. McDonald Observatory, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712-0259 (United States)

2013-08-20

410

DO R CORONAE BOREALIS STARS FORM FROM DOUBLE WHITE DWARF MERGERS?  

SciTech Connect

A leading formation scenario for R Coronae Borealis (RCB) stars invokes the merger of degenerate He and CO white dwarfs (WDs) in a binary. The observed ratio of {sup 16}O/{sup 18}O for RCB stars is in the range of 0.3-20 much smaller than the solar value of {approx}500. In this paper, we investigate whether such a low ratio can be obtained in simulations of the merger of a CO and a He WD. We present the results of five three-dimensional hydrodynamic simulations of the merger of a double WD system where the total mass is 0.9 M{sub Sun} and the initial mass ratio (q) varies between 0.5 and 0.99. We identify in simulations with q {approx}< 0.7 a feature around the merged stars where the temperatures and densities are suitable for forming {sup 18}O. However, more {sup 16}O is being dredged up from the C- and O-rich accretor during the merger than the amount of {sup 18}O that is produced. Therefore, on the dynamical timescale over which our hydrodynamics simulation runs, an {sup 16}O/{sup 18}O ratio of {approx}2000 in the 'best' case is found. If the conditions found in the hydrodynamic simulations persist for 10{sup 6} s the oxygen ratio drops to 16 in one case studied, while in a hundred years it drops to {approx}4 in another case studied, consistent with the observed values in RCB stars. Therefore, the merger of two WDs remains a strong candidate for the formation of these enigmatic stars.

Staff, Jan. E.; Clayton, Geoffrey C.; Tohline, Joel E. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States); Menon, Athira; Herwig, Falk [Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P5C2 (Canada); Even, Wesley; Fryer, Chris L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Motl, Patrick M. [Department of Science, Mathematics and Informatics, Indiana University Kokomo, Kokomo, IN 46904-9003 (United States); Geballe, Tom [Gemini Observatory, 670 North A'ohoku Place, Hilo, HI 96720 (United States); Pignatari, Marco [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

2012-09-20

411

Bioturbating shrimp alter the structure and diversity of bacterial communities in coastal marine sediments.  

PubMed

Bioturbation is a key process in coastal sediments, influencing microbially driven cycling of nutrients as well as the physical characteristics of the sediment. However, little is known about the distribution, diversity and function of the microbial communities that inhabit the burrows of infaunal macroorganisms. In this study, terminal-restriction fragment length polymorphism analysis was used to investigate variation in the structure of bacterial communities in sediment bioturbated by the burrowing shrimp Upogebia deltaura or Callianassa subterranea. Analyses of 229 sediment samples revealed significant differences between bacterial communities inhabiting shrimp burrows and those inhabiting ambient surface and subsurface sediments. Bacterial communities in burrows from both shrimp species were more similar to those in surface-ambient than subsurface-ambient sediment (R=0.258, P<0.001). The presence of shrimp was also associated with changes in bacterial community structure in surrounding surface sediment, when compared with sediments uninhabited by shrimp. Bacterial community structure varied with burrow depth, and also between individual burrows, suggesting that the shrimp's burrow construction, irrigation and maintenance behaviour affect the distribution of bacteria within shrimp burrows. Subsequent sequence analysis of bacterial 16S rRNA genes from surface sediments revealed differences in the relative abundance of bacterial taxa between shrimp-inhabited and uninhabited sediments; shrimp-inhabited sediment contained a higher proportion of proteobacterial sequences, including in particular a twofold increase in Gammaproteobacteria. Chao1 and ACE diversity estimates showed that taxon richness within surface bacterial communities in shrimp-inhabited sediment was at least threefold higher than that in uninhabited sediment. This study shows that bioturbation can result in significant structural and compositional changes in sediment bacterial communities, increasing bacterial diversity in surface sediments and resulting in distinct bacterial communities even at depth within the burrow. In an area of high macrofaunal abundance, this could lead to alterations in the microbial transformations of important nutrients at the sediment-water interface. PMID:20596074

Laverock, Bonnie; Smith, Cindy J; Tait, Karen; Osborn, A Mark; Widdicombe, Steve; Gilbert, Jack A

2010-12-01

412

Immune response and disease resistance of shrimp fed biofloc grown on different carbon sources.  

PubMed

The objective of this study was to document the immunological effects of growing shrimp in biofloc systems. The experiment consisted of four types of biofloc systems in which bioflocs were produced by daily supplementation of four different carbon sources, i.e. molasses, tapioca, tapioca-by-product, and rice bran, at an estimated C/N ratio of 15 and a control system without any organic carbon addition. Each biofloc system was stocked with Pacific white shrimp (Litopenaeus vannamei) juveniles that were reared for 49 days. The use of tapioca-by-product resulted in a higher survival (93%) of the shrimp as compared to the other carbon sources and the control. The highest yield and protein assimilation was observed when tapioca was used as the carbon source. After 49 days, phenoloxidase (PO) activity of the shrimp grown in all biofloc systems was higher than that of the shrimp from the control system. Following a challenge test by injection with infectious myonecrosis virus (IMNV), the levels of PO and respiratory burst (RB) activity in the shrimp of all biofloc treatments were higher than that of the challenged shrimp from the control treatment. An increased immunity was also suggested by the survival of the challenged shrimp from the experimental biofloc groups that was significantly higher as compared to the challenged shrimp from the control treatment, regardless of the organic carbon source used to grow the bioflocs. Overall, this study demonstrated that the application of biofloc technology may contribute to the robustness of cultured shrimp by immunostimulation and that this effect is independent of the type of carbon source used to grow the flocs. PMID:25218685

Ekasari, Julie; Hanif Azhar, Muhammad; Surawidjaja, Enang H; Nuryati, Sri; De Schryver, Peter; Bossier, Peter

2014-12-01

413

New R Coronae Borealis stars discovered in OGLE-III Galactic Bulge fields from their mid- and near- infrared properties  

E-print Network

An R Coronae Borealis (RCB) star is a rare type of supergiant star that is increasingly thought to be the evolved merger product of two white dwarfs. Recently, many of them have been found distributed in a thin disk structure embedded inside the Galactic Bulge. This unexpected high density can give us more insight into the nature and age of RCB stars. We applied and tested successfully a new technique to find RCB stars based on the particular infrared emission. We demonstrated that RCB stars can now be found without the need of a light curve analysis, and therefore outside optically monitored fields. The selection of RCB candidates was based on their near-infrared excess and on particular mid-infrared emission of RCB shells, using photometric data from the 2MASS and Spitzer/GLIMPSE surveys. The OGLE light curves of all RCB candidates were then inspected visually and the ones presenting large and fast declines were followed-up spectroscopically . We discovered two new R Coronae Borealis stars, but also propose...

Tisserand, P; Wood, P R; Udalski, A; Szyma?ski, M K; Kubiak, M; Pietrzy?ski, G; Soszy?ski, I; Szewczyk, O; Ulaczyk, K; Poleski, R

2010-01-01

414

Strike mechanics of an ambush predator: the spearing mantis shrimp.  

PubMed

Ambush predation is characterized by an animal scanning the environment from a concealed position and then rapidly executing a surprise attack. Mantis shrimp (Stomatopoda) consist of both ambush predators ('spearers') and foragers ('smashers'). Spearers hide in sandy burrows and capture evasive prey, whereas smashers search for prey away from their burrows and typically hammer hard-shelled, sedentary prey. Here, we examined the kinematics, morphology and field behavior of spearing mantis shrimp and compared them with previously studied smashers. Using two species with dramatically different adult sizes, we found that strikes produced by the diminutive species, Alachosquilla vicina, were faster (mean peak speed 5.72±0.91 m s(-1); mean duration 3.26±0.41 ms) than the strikes produced by the large species, Lysiosquillina maculata (mean peak speed 2.30±0.85 m s(-1); mean duration 24.98±9.68 ms). Micro-computed tomography and dissections showed that both species have the spring and latch structures that are used in other species for producing a spring-loaded strike; however, kinematic analyses indicated that only A. vicina consistently engages the elastic mechanism. In the field, L. maculata ambushed evasive prey primarily at night while hidden in burrows, striking with both long and short durations compared with laboratory videos. We expected ambush predators to strike with very high speeds, yet instead we found that these spearing mantis shrimp struck more slowly and with longer durations than smashers. Nonetheless, the strikes of spearers occurred at similar speeds and durations to those of other aquatic predators of evasive prey. Although counterintuitive, these findings suggest that ambush predators do not actually need to produce extremely high speeds, and that the very fastest predators are using speed to achieve other mechanical feats, such as producing large impact forces. PMID:23175528

deVries, M S; Murphy, E A K; Patek, S N

2012-12-15

415

Organotins in North Sea brown shrimp (Crangon crangon L.) after implementation of the TBT ban.  

PubMed

The organotin (OT) compounds tributyltin (TBT) and triphenyltin (TPhT) are potent biocides that have been used ubiquitously in antifouling paints and pesticides since the mid-1970s. These biocides are extremely toxic to marine life, particularly marine gastropod populations. The European Union therefore took measures to reduce the use of TBT-based antifouling paints on ships and ultimately banned these paints in 2003. Despite sufficient data on OT concentrations in marine gastropods, data are scarce for other species such as the North Sea brown shrimp (Crangon crangon), a dominant crustacean species in North Sea inshore benthic communities. The present study provides the first spatial overview of OT concentrations in North Sea brown shrimp. We have compared these data with historical concentrations in shrimp as well as with sediment concentrations. We have also addressed the effect on the shrimp stock and any human health risks associated with the OT concentrations found. TBT and TPhT in shrimp tail muscle ranged from 4 to 124 and from 1 to 24 ?g kg(-1) DW, respectively. High levels are accumulated in estuarine areas and are clearly related with sediment concentrations (biota-sediment accumulation factor ~10). Levels have decreased approximately 10-fold since the ban took effect, coinciding with a recovery of the shrimp stock after 30 years of gradual regression. Furthermore, the OT levels found in brown shrimp no longer present a human health risk. PMID:22154339

Verhaegen, Y; Monteyne, E; Neudecker, T; Tulp, I; Smagghe, G; Cooreman, K; Roose, P; Parmentier, K

2012-03-01

416

Characterization of Intestinal Bacteria in Wild and Domesticated Adult Black Tiger Shrimp (Penaeus monodon)  

PubMed Central

The black tiger shrimp (Penaeus monodon) is a marine crustacean of economic importance in the world market. To ensure sustainability of the shrimp industry, production capacity and disease outbreak prevention must be improved. Understanding healthy microbial balance inside the shrimp intestine can provide an initial step toward better farming practice and probiotic applications. In this study, we employed a barcode pyrosequencing analysis of V3-4 regions of 16S rRNA genes to examine intestinal bacteria communities in wild-caught and domesticated P. monodon broodstock. Shrimp faeces were removed from intestines prior to further analysis in attempt to identify mucosal bacterial population. Five phyla, Actinobacteria, Fusobacteria, Proteobacteria, Firmicutes and Bacteroidetes, were found in all shrimp from both wild and domesticated environments. The operational taxonomic unit (OTU) was assigned at 97% sequence identity, and our pyrosequencing results identified 18 OTUs commonly found in both groups. Sequences of the shared OTUs were similar to bacteria in three phyla, namely i) Proteobacteria (Vibrio, Photobacterium, Novosphingobium, Pseudomonas, Sphingomonas and Undibacterium), ii) Firmicutes (Fusibacter), and iii) Bacteroidetes (Cloacibacterium). The shared bacterial members in P. monodon from two different habitats provide evidence that the internal environments within the host shrimp also exerts selective pressure on bacterial members. Intestinal bacterial profiles were compared using denaturing gradient gel electrophoresis (DGGE). The sequences from DGGE bands were similar to those of Vibrio and Photobacterium in all shrimp, consistent with pyrosequencing results. This work provides the first comprehensive report on bacterial populations in the intestine of adult black tiger shrimp and reveals some similar bacterial members between the intestine of wild-caught and domesticated shrimp. PMID:24618668

Rungrassamee, Wanilada; Klanchui, Amornpan; Maibunkaew, Sawarot; Chaiyapechara, Sage; Jiravanichpaisal, Pikul; Karoonuthaisiri, Nitsara

2014-01-01

417

Characterization of intestinal bacteria in wild and domesticated adult black tiger shrimp (Penaeus monodon).  

PubMed

The black tiger shrimp (Penaeus monodon) is a marine crustacean of economic importance in the world market. To ensure sustainability of the shrimp industry, production capacity and disease outbreak prevention must be improved. Understanding healthy microbial balance inside the shrimp intestine can provide an initial step toward better farming practice and probiotic applications. In this study, we employed a barcode pyrosequencing analysis of V3-4 regions of 16S rRNA genes to examine intestinal bacteria communities in wild-caught and domesticated P. monodon broodstock. Shrimp faeces were removed from intestines prior to further analysis in attempt to identify mucosal bacterial population. Five phyla, Actinobacteria, Fusobacteria, Proteobacteria, Firmicutes and Bacteroidetes, were found in all shrimp from both wild and domesticated environments. The operational taxonomic unit (OTU) was assigned at 97% sequence identity, and our pyrosequencing results identified 18 OTUs commonly found in both groups. Sequences of the shared OTUs were similar to bacteria in three phyla, namely i) Proteobacteria (Vibrio, Photobacterium, Novosphingobium, Pseudomonas, Sphingomonas and Undibacterium), ii) Firmicutes (Fusibacter), and iii) Bacteroidetes (Cloacibacterium). The shared bacterial members in P. monodon from two different habitats provide evidence that the internal environments within the host shrimp also exerts selective pressure on bacterial members. Intestinal bacterial profiles were compared using denaturing gradient gel electrophoresis (DGGE). The sequences from DGGE bands were similar to those of Vibrio and Photobacterium in all shrimp, consistent with pyrosequencing results. This work provides the first comprehensive report on bacterial populations in the intestine of adult black tiger shrimp and reveals some similar bacterial members between the intestine of wild-caught and domesticated shrimp. PMID:24618668

Rungrassamee, Wanilada; Klanchui, Amornpan; Maibunkaew, Sawarot; Chaiyapechara, Sage; Jiravanichpaisal, Pikul; Karoonuthaisiri, Nitsara

2014-01-01

418

Effect of chitosan-based edible coating on preservation of white shrimp during partially frozen storage.  

PubMed

Chitosan and chitooligosaccharides are preservatives with proven antibacterial activity, while glutathione has antioxidant activity. This study investigated the effects of chitosan coating combined with chitooligosaccharides and glutathione (0.8% glutathione+1% chitooligosaccharides+1% chitosan) on preservation of white shrimp (Penaeus vannamei) during partially frozen storage. Chitosan-based coating treatments effectively inhibited bacterial growth, reduced total volatile basic nitrogen and malondialdehyde, and basically maintained the sensory properties of white shrimp (P. vannamei) during partially frozen storage. Therefore, chitosan-based edible coating combined with chitooligosaccharides and glutathione could be a promising antimicrobial and oxidant method to prevent metamorphism of white shrimp with extended shelf life. PMID:24491494

Wu, Shengjun

2014-04-01

419

An XMM-Newton Study of the Coronae of ?2 Coronae Borealis  

NASA Astrophysics Data System (ADS)

We present results of XMM-Newton Guaranteed Time observations of the RS CVn binary ?2 Coronae Borealis. The spectra obtained with the Reflection Grating Spectrometers and the European Photon Imaging Camera MOS2 were simultaneously fitted with collisional ionization equilibrium plasma models to determine coronal abundances of various elements. Contrary to the solar first ionization potential (FIP) effect, in which elements with a low FIP are overabundant in the corona compared to the solar photosphere, and contrary to the ``inverse'' FIP effect observed in several active RS CVn binaries, coronal abundance ratios in ?2 CrB show a complex pattern, as supported by similar findings in the Chandra HETGS analysis of ?2 CrB with a different methodology by Osten and coworkers in 2003. Low-FIP elements (<10 eV) have abundance ratios relative to Fe that are consistent with the solar photospheric ratios, whereas high-FIP elements have abundance ratios that increase with increasing FIP. We find that the coronal Fe abundance is consistent with the stellar photospheric value, indicating that there is no metal depletion in ?2 CrB. However, we obtain a higher Fe absolute abundance than Osten and coworkers did. Except for Ar and S, our absolute abundances are about 1.5 times larger than those reported by Osten and coworkers. However, a comparison of their model with our XMM-Newton data (and vice versa) shows that both models work adequately in general. We find, therefore, no preference for one methodology over the other for deriving coronal abundances. Despite the systematic discrepancy in absolute abundances, our abundance ratios are very close to those obtained by Osten and coworkers. Finally, we confirm the measurement of a low density in O VII (<4×1010 cm-3) but could not confirm the higher densities measured in spectral lines formed at higher temperatures that were derived by other studies of ?2 CrB due to the lower spectral resolution of the XMM-Newton grating spectrometers.

Suh, Jin A.; Audard, Marc; Güdel, Manuel; Paerels, Frederik B. S.

2005-09-01

420

The Circumstellar Environment of R Coronae Borealis: White Dwarf Merger or Final-helium-shell Flash?  

NASA Astrophysics Data System (ADS)

In 2007, R Coronae Borealis (R CrB) went into a historically deep and long decline. In this state, the dust acts like a natural coronagraph at visible wavelengths, allowing faint nebulosity around the star to be seen. Imaging has been obtained from 0.5 to 500 ?m with Gemini/GMOS, Hubble Space Telescope/WFPC2, Spitzer/MIPS, and Herschel/SPIRE. Several of the structures around R CrB are cometary globules caused by wind from the star streaming past dense blobs. The estimated dust mass of the knots is consistent with their being responsible for the R CrB declines if they form along the line of sight to the star. In addition, there is a large diffuse shell extending up to 4 pc away from the star containing cool 25 K dust that is detected all the way out to 500 ?m. The spectral energy distribution of R CrB can be well fitted by a 150 AU disk surrounded by a very large diffuse envelope which corresponds to the size of the observed nebulosity. The total masses of the disk and envelope are 10-4 and 2 M ?, respectively, assuming a gas-to-dust ratio of 100. The evidence pointing toward a white dwarf merger or a final-helium-shell flash origin for R CrB is contradictory. The shell and the cometary knots are consistent with a fossil planetary nebula. Along with the fact that R CrB shows significant lithium in its atmosphere, this supports the final-helium-shell flash. However, the relatively high inferred mass of R CrB and its high fluorine abundance support a white dwarf merger. Based in part on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, and from the data archive at STScI, which are operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Clayton, Geoffrey C.; Sugerman, Ben E. K.; Stanford, S. Adam; Whitney, B. A.; Honor, J.; Babler, B.; Barlow, M. J.; Gordon, K. D.; Andrews, J. E.; Geballe, T. R.; Bond, Howard E.; De Marco, O.; Lawson, W. A.; Sibthorpe, B.; Olofsson, G.; Polehampton, E.; Gomez, H. L.; Matsuura, M.; Hargrave, P. C.; Ivison, R. J.; Wesson, R.; Leeks, S. J.; Swinyard, B. M.; Lim, T. L.

2011-12-01

421

R Coronae Borealis Stars As The Result Of White Dwarf Mergers?  

NASA Astrophysics Data System (ADS)

R Coronae Borealis (RCB) stars have masses around a solar mass, are hydrogen-deficient variable stars that suddenly fade by several magnitudes at irregular intervals after which they gradually return to their original brightness over a period of some months. The fading is thought to be due to the formation of dust blocking light from the star. RCBs are often thought to be the result of the merger of a He and a CO white dwarfs. Here we present the results of 3 dimensional hydrodynamic simulations of the merger of double white dwarf systems where total mass is 0.9 solar mass and initial mass ratios ranging between q=0.5 and q=1. We use a zero-temperature plus ideal gas equation of state that allows for heating through shocks. These simulations allow us to follow the evolution of the system for 10-20 initial orbital periods (1000-2000 seconds) to a point after merger when the combined object has settled into a nearly steady-state like configuration. A hot shell forms around the merged core in low q simulations, but not in the high q simulations. The conditions found in the steady state like configuration is used as input to a nucleosynthesis code. We are particularly interested in seeing how much 18O is formed, as observations of RCB stars often show a very high ratio of 18O to 16O of order unity. In the very best case scenario, we find a ratio of 1/12 in the hot shell. This work has been supported, in part, by grant OIA-0963375 from the U.S. National Science Foundation and, in part, by NASA/ATP grants NNX10AC72G. This research also has been made possible by grants of high-performance computing time on the TeraGrid (TG-AST090104), at LSU, and across LONI (Louisiana Optical Network Initiative), especially awards loni_astro08 and loni_astro09).

Staff, Jan E.; Menon, A.; Herwig, F.; Even, W.; Clayton, G.; Tohline, J.; Fryer, C. L.; Motl, P.; Geballe, T.

2012-01-01

422

The ongoing pursuit of R Coronae Borealis stars: the ASAS-3 survey strikes again  

NASA Astrophysics Data System (ADS)

Context. R Coronae Borealis stars (RCBs) are rare, hydrogen-deficient, carbon-rich supergiant variable stars that are likely the evolved merger products of pairs of CO and He white dwarfs. Only 55 RCB stars have been found in our galaxy and their distribution on the sky is weighted heavily by microlensing survey field positions. A less biased wide-area survey would enable us to test competing evolutionary scenarios, understand the population or populations that produce RCBs, and constrain their formation rate. Aims: The ASAS-3 survey monitored the sky south of declination +28 deg between 2000 and 2010 to a limiting magnitude of V = 14. We searched ASAS-3 for RCB variables using several different methods to ensure that the probability of RCB detection was as high as possible and to reduce selection biases based on luminosity, temperature, dust production activity and shell brightness. Methods: Candidates whose light curves were visually inspected were pre-selected based on their infrared (IR) excesses due to warm dust in their circumstellar shells using the WISE and/or 2MASS catalogues. Criteria on light curve variability were also applied when necessary to minimise the number of objects. Initially, we searched for RCB stars among the ASAS-3 ACVS1.1 variable star catalogue, then among the entire ASAS-3 south source catalogue, and finally directly interrogated the light curve database for objects that were not catalogued in either of those. We then acquired spectra of 104 stars to determine their real nature using the SSO/WiFeS spectrograph. Results: We report 21 newly discovered RCB stars and 2 new DY Per stars. Two previously suspected RCB candidates were also spectroscopically confirmed. Our methods allowed us to extend our detection efficiency to fainter magnitudes that would not have been easily accessible to discovery techniques based on light curve variability. The overall detection efficiency is about 90% for RCBs with maximum light brighter than V ~ 13. Conclusions: With these new discoveries, 76 RCBs are now known in our Galaxy and 22 in the Magellanic Clouds. This growing sample is of great value to constrain the peculiar and disparate atmosphere composition of RCBs. Most importantly, we show that the spatial distribution and apparent magnitudes of Galactic RCB stars is consistent with RCBs being part of the Galactic bulge population.

Tisserand, P.; Clayton, G. C.; Welch, D. L.; Pilecki, B.; Wyrzykowski, L.; Kilkenny, D.

2013-03-01

423

What is the True Population of R Coronae Borealis Stars in the Galaxy?  

NASA Astrophysics Data System (ADS)

The R Coronae Borealis (RCB) stars are rare hydrogen-deficient, carbon-rich supergiants. Two evolutionary scenarios have been suggested, a double degenerate merger of two white dwarfs (WDs), or a final helium shell flash in a PN central star. The evidence pointing toward a WD merger or a FF origin for RCB stars is contradictory. The distribution on the sky and radial velocities of the RCB stars tend toward those of the bulge population but a much larger sample of stars is needed to determine the true population. We need to discover RCB much more efficiently. In order to do this we are pursuing three lines of attack: 1. Light Curves: Using the traditional technique of identifying RCB stars from their characteristic large and irregular light variations, we have we have investigated the stars in the ASAS-3 south survey. We have discovered 21 new RCB stars. The different analysis applied allowed us to extend our detection efficiency to fainter magnitudes that would not have been easily accessible to classical analysis based on light-curve variability. 2. Color-Color Diagrams: All RCB stars have IR excesses. Using the recent release of the WISE All-Sky Catalog, a series of IR color-color cuts have produced a sample of candidates 1600) that may yield over 200 new RCB star identifications. A pilot project to get spectra of the 200 brighter candidates has yielded an unexpectedly high new discovery rate 20%) based on photometric colors alone. 3. Spectral Classification: We are attempting to develop a quantitative spectral classification system for the RCB stars so that they can perhaps be identified without an accompanying light curve. The cooler RCB stars look like carbon stars with strong C2 bands, but they can be differentiated from carbon stars by their extreme hydrogen deficiency and very low 13C/12C ratio. Also, the red CN bands are much weaker in RCB stars than in carbon stars. The number of RCB stars in the Galaxy may be consistent with the predicted number of He/CO WD mergers. Solving the mystery of how the RCB stars evolve would be a watershed event in the study of stellar evolution that will lead to a better understanding of other important types of stellar merger events such as Type Ia SNe.

Clayton, Geoffrey C.; Tisserand, P.; Welch, D. L.; Zhang, W.

2013-01-01

424

Tracking down R Coronae Borealis stars from their mid-infrared WISE colours  

NASA Astrophysics Data System (ADS)

Context. R Coronae Borealis stars (RCBs) are hydrogen-deficient and carbon-rich supergiant stars. They are very rare, with only ~50 actually known in our Galaxy. Interestingly, RCBs are strongly suspected of being the evolved merger product of two white dwarfs and could therefore be an important tool for understanding supernovae type Ia in the double degenerate scenario. Constraints on the spatial distribution and the formation rate of such stars are needed to picture their origin and test it in the context of actual population synthesis results. Aims: It is crucial to increase the number of known RCBs significantly. With an absolute magnitude MV ~ -5 and a bright/hot circumstellar shell made of amorphous carbon grains, RCBs are so distinctive that we should nowadays be able to find them everywhere in our Galaxy using publicly available catalogues. In the optical, the search is difficult because RCBs are known to undergo unpredictable photometric declines; however, mono-epoch mid-infrared data can help us to discriminate RCBs among other dust-producing stars. The aim is to produce from the mid-infrared WISE and near-infrared 2MASS catalogues a new catalogue of reasonable size, enriched with RCB stars. Methods: Colour-colour cuts used on all stars detected are the main selection criteria. The selection efficiency was monitored using the 52 known RCBs located in the sky area covered by the WISE first preliminary data release. Results: It has been found that selection cuts in mid-infrared colour-colour diagrams are a very efficient method of distinguishing RCBs from other stars. An RCB enriched catalogue made of only 1602 stars was produced, with a high detection efficiency of about 77%. Spectral energy distributions of 49 known RCBs and 5 known HdCs are also presented with estimates of their photosphere and circumstellar shell temperatures. Conclusions: The newly released WISE all sky catalogue has proven to be a valuable resource in finding RCB stars. Actual scenarios predict that between 100 and 500 RCBs exist in our Galaxy. The newly created RCB enriched catalogue is an important step towards significantly increasing the number of known RCB stars and therefore better understanding their origin. Tables 3-5 ara available in electronic form at http://www.aanda.orgFull Table 5 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/539/A51

Tisserand, P.

2012-03-01

425

Double white dwarf mergers and elemental surface abundances in extreme helium and R Coronae Borealis stars  

NASA Astrophysics Data System (ADS)

The surface abundances of extreme helium (EHe) and R Coronae Borealis (RCB) stars are discussed in terms of a model for their origin in the merger of a carbon-oxygen white dwarf with a helium white dwarf. The model is expressed as a linear mixture of the individual layers of both constituent white dwarfs, taking account of the specific evolution of each star. In developing this recipe from previous versions, particular attention has been given to the intershell abundances of the asymptotic giant branch (AGB) star which evolved to become the carbon-oxygen white dwarf. Thus the surface composition of the merged star is estimated as a function of the initial mass and metallicity of its progenitor. The question of whether additional nucleosynthesis occurs during the white dwarf merger has been examined by including the results of recent hydrodynamical merger calculations which incorporate the major nuclear networks. The high observed abundances of carbon and oxygen must either originate by dredge-up from the core of the carbon-oxygen white dwarf during a cold merger or be generated directly by ? burning during a hot merger. The presence of large quantities of 18O may be consistent with both scenarios, since a significant 18O pocket develops at the carbon/helium boundary in a number of our post-AGB models. The production of fluorine, neon and phosphorus in the AGB intershell propagates through to an overabundance at the surface of the merged stars, but generally not in sufficient quantity to match the observed abundances. However, the evidence for an AGB origin for these elements, together with near-normal abundances of magnesium, points to progenitor stars with initial masses in the range 1.9-3 M?. There is not yet sufficient understanding of the chemical structure of CO white dwarfs, or of nucleosynthesis during a double white dwarf merger, to discriminate the origin (fossil or prompt) of all the abundance anomalies observed in EHe and RCB stars. Further work is required to quantify the expected yields of argon and s-process elements in the AGB intershell, and to improve the predicted yields of all elements from a hot merger.

Jeffery, C. S.; Karakas, A. I.; Saio, H.

2011-07-01

426

Baryonic Matter at Supercluster Scales: The Case of the Corona Borealis Supercluster  

NASA Astrophysics Data System (ADS)

In a 24deg2 survey for baryonic matter at 33GHz in the Corona Borealis supercluster (CrB-SC) of galaxies (z=0.07), with the Very Small Array (VSA) interferometer (Génova-Santos et al. 2005, MNRAS 363, 79; 2008, arXiv: 0804.0199), we found a very strong temperature decrement in the Cosmic Microwave Background (CMB). It has an amplitude of-230±23?K and is located near the center of the supercluster, in a position with no known galaxy clusters, and without a significant X-ray emission in the ROSAT All-Sky Survey. Monte-Carlo simulations discard the primordial CMB Gaussian field as a possible explanation for this decrement at a level of 99.6%. We therefore concluded that this could be indicative of a Sunyaev-Zel'dovich (SZ) effect produced either by a warm/hot gas distribution in the intercluster medium or by a farther unknown galaxy cluster. Here we present an optical study of the galaxy distribution in this region, aiming at elucidating whether it traces a possible warm/hot gas filamentary distribution or a galaxy cluster. First, we have studied the galaxy population down to r?20 magnitudes in the SDSS. This reveals an overdensity by a factor of 2 with respect to nearby control fields, but lower than in the galaxy clusters member of the CrB-SC. This indicates that the associated gas could at least be partially responsible for the observed CMB decrement. Second, we obtained spectroscopic redshifts, with the William Herschel Telescope (WHT), for a sample of galaxies in the region of the cold spot, and found evidence of a substructure with redshifts extending from 0.07 to 0.10. This suggests the existence of a dense filamentary structure with a length of several tens of Mpc. Finally, we investigated the presence of at least one farther cluster in the same line-of-sight, at z?0.11.

Padilla-Torres, Carmen Pilar; Rebolo, Rafael; Gutiérrez, Carlos M.; Génova-Santos, Ricardo; Rubiño-Martin, José Alberto

427

Structure of Penaeus stylirostris Densovirus, a Shrimp Pathogen  

SciTech Connect

Penaeus stylirostris densovirus (PstDNV), a pathogen of penaeid shrimp, causes significant damage to farmed and wild shrimp populations. In contrast to other parvoviruses, PstDNV probably has only one type of capsid protein that lacks the phospholipase A2 activity that has been implicated as a requirement during parvoviral host cell infection. The structure of recombinant virus-like particles, composed of 60 copies of the 37.5-kDa coat protein, the smallest parvoviral capsid protein reported thus far, was determined to 2.5-{angstrom} resolution by X-ray crystallography. The structure represents the first near-atomic resolution structure within the genus Brevidensovirus. The capsid protein has a {beta}-barrel 'jelly roll' motif similar to that found in many icosahedral viruses, including other parvoviruses. The N-terminal portion of the PstDNV coat protein adopts a 'domain-swapped' conformation relative to its twofold-related neighbor similar to the insect parvovirus Galleria mellonella densovirus (GmDNV) but in stark contrast to vertebrate parvoviruses. However, most of the surface loops have little structural resemblance to any of the known parvoviral capsid proteins.

Kaufmann, Bärbel; Bowman, Valorie D.; Li, Yi; Szelei, Jozsef; Waddell, Peter J.; Tijssen, Peter; Rossmann, Michael G. (INRS); (Purdue)

2010-11-16

428

Stability studies on astaxanthin extracted from fermented shrimp byproducts.  

PubMed

To the best of our knowledge, stability studies on astaxanthin contained in carotenoproteins extracted from lactic acid fermented shrimp byproduct have never been reported. Carotenoprotein powder, containing 1% free astaxanthin, was subjected to oxidation factors of illumination, oxygen availability, and temperature, using synthetic astaxanthin as a control. The individual effects as well as first and second degree interactions were studied on natural and synthetic free astaxanthin stability. Air and full light were the two individual factors with the highest effects on astaxanthin oxidation. Sixty-two and 46% natural and synthetic astaxanthin, respectively, oxidized when exposed to air for 8 weeks of storage, whereas 35 and 28% of natural and synthetic astaxanthin, respectively, oxidized under full light. Ninety-seven and 88% of natural and synthetic astaxanthin, respectively, oxidized under a combination of full light, air, and 45 degrees C at 8 weeks of storage. Storage in the dark, nonoxygen, and 25 degrees C were the treatments that efficiently minimized astaxanthin oxidation. Natural astaxanthin from fermented shrimp byproduct presented moderate stability levels. Although natural astaxanthin oxidized faster than the synthetic pigment, its stability may improve by antioxidant and polymer addition. PMID:19548684

Armenta, Roberto E; Guerrero-Legarreta, Isabel

2009-07-22

429

The Case Low-Dispersion Northern Sky Survey. XIII - A region in central Bootes and Corona Borealis  

NASA Astrophysics Data System (ADS)

Positions, estimated magnitudes, and finding charts (when necessary) are provided for 138 blue and/or emission-line galaxies, four H II regions in two galaxies, 83 unresolved blue and/or emission-line objects, including QSO candidates, and 36 known and suspected blue stars in a about 100 sq deg region in central Bootes and Corona Borealis encompassed primarily in the region R.A. between 14h 08m and 16h 10m and Decl. between 29 deg 30 min and 33 deg 30 min (1950). The objects, whose blue magnitudes are mostly within the range 15-18, were identified on low-dispersion objective-prism plates taken with the Burrell Schmidt telescope at Kitt Peak.

Stephenson, C. B.; Pesch, Peter; MacConnell, D. J.

1992-10-01

430

High-resolution optical spectroscopy of the R Coronae Borealis star V532 Ophiuchi at maximum light  

E-print Network

High-resolution optical spectra of the R Coronae Borealis (RCB) star V532 Oph at light maximum are discussed. The absolute visual magnitude M_V of the star is found to be -4.9 \\pm 0.5. The elemental abundances suggest the star belongs to the majority class of RCB stars but is among the most O-poor of this class with mild enhancements of heavy elements Y, Zr, Ba and La. The C_2 Swan bands are weak in V532 Oph relative to R CrB. Other aspects of the high-resolution spectrum confirm that V532 Oph is representative of majority RCBs, i.e., the radial velocity is variable, circumstellar material is present and the photosphere feeds a high-velocity stellar wind.

Rao, N Kameswara; Woolf, Vincent M; Hema, B P

2014-01-01

431

Infrared Space Observatory Spectra of R Coronae Borealis Stars. I. Emission Features in the Interval 3 - 25 microns  

E-print Network

Infrared Space Observatory 3 - 25 $\\mu$m spectra of the R Coronae Borealis stars V854 Cen, R CrB, and RY Sgr are presented and discussed. Sharp emission features coincident in wavelengths with the well known Unidentified Emission Features are present in the spectrum of V854 Cen but not of R CrB or RY Sgr. Since V854 Cen is not particularly H-poor and has a 1000 times more H than the other stars, the emission features are probably from a carrier containing hydrogen. There is a correspondence between the features and emission from laboratory samples of hydrogenated amorphous carbon. A search for C$_{60}$ in emission or absorption proved negative. Amorphous carbon particles account for the broad emission features seen between 6 - 14 $\\mu$m in the spectrum of each star.

David L. Lambert; N. Kameswara Rao; Gajendra Pandey; Inese I. Ivans

2001-03-23

432

A Combined HIPPARCOS and Multichannel Astrometric Photometer Study of the Proposed Planetary System of Rho Coronae Borealis  

NASA Technical Reports Server (NTRS)

Hipparcos and Multichannel Astrometric Photometer (MAP) observations of rho Coronae Borealis independently display astrometric motion at the period of the proposed extrasolar planetary companion to the star. Individual least-squares fits to each astrometric data set yield independent estimates of the semimajor axis, inclination, and node angle that are in excellent agreement. A combined solution of the Hipparcos and MAP data yields an inclination of 0.5 deg, a node at 30.5 +/- 12.4, and a semimajor axis of 1.66 +/- 0.35 mas, indicating a companion mass of 0.14 +/- 0.05 solar masses over two orders of magnitude greater than the minimum mass for the companion as determined by radial velocity studies. This mass is approximately that of an M dwarf star, the companion cannot be a planetary object.

Gatewood, George; Han, Inwoo; Black, David C.

2001-01-01

433

Beppo-SAX temperature maps of galaxy clusters in the Corona Borealis supercluster: A2061, A2067 and A2124  

E-print Network

In this paper we present the analysis of Beppo-SAX observations of the cluster pairs A2061-A2067 and A2122-A2124, located in the Corona Borealis supercluster, which have been selected as candidate merging clusters. The aim of this work is to study the physics of the intracluster medium and to look for the possible presence of merging signatures. We derived the global temperatures and abundances and the temperature profiles and maps for these clusters. We do not find any significant evidence of interaction between the clusters forming the pairs, but we detect a candidate shock inside A2061. On the basis of the X-ray and optical properties of this cluster we propose a scenario in which a group is falling inside A2061. This interaction is in the phase in which the cores have not encountered yet and in which the formation of a shock is expected.

F. Marini; S. Bardelli; E. Zucca; S. De Grandi; A. Cappi; S. Ettori; L. Moscardini; G. Tormen; A. Diaferio

2004-06-24

434

Comparison of NIMS and MALDI platforms for neuropeptide and lipid mass spectrometric imaging in C. borealis brain tissue  

PubMed Central

Nanostructure-initiator mass spectrometry (NIMS) is a recently developed matrix-free laser desorption/ionization technique that has shown promise for peptide analyses. It is also useful in mass spectrometric imaging (MSI) studies of small molecule drugs, metabolites, and lipids, minimizing analyte diffusion caused by matrix application. In this study, NIMS and matrix-assisted laser desorption/ionization (MALDI) MSI of a crustacean model organism Cancer borealis brain were compared. MALDI was found to perform better than NIMS in these neuropeptide imaging experiments. Twelve neuropeptides were identified in MALDI MSI experiments whereas none were identified in NIMS MSI experiments. In addition, lipid profiles were compared using each ionization method. Both techniques provided similar lipid profiles in the m/z range 700 – 900. PMID:23544036

Sturm, Robert M; Greer, Tyler; Chen, Ruibing; Hensen, Broderick; Li, Lingjun

2013-01-01

435

Transboundary movement of shrimp viruses in crustaceans and their products: a special risk?  

PubMed

Shrimp and shrimp products form the most valuable internationally traded fisheries commodity, and the volumes are huge, estimated to be about 3.6 million tonnes. However, despite the existence under the General Agreement on Tariffs and Trade, of the Sanitary and Phytosanitary Measures (SPS Agreement) and the activities of the World Organisation for Animal Health (OIE), viral shrimp epizootics have spread and continue to spread, affecting world production. Though most attention has focussed on the movement of live shrimp product, the spread of new and emerging diseases through other crustaceans and their nonviable products is of increasing concern. The risks associated with the unrestricted movement of nonviable product will be outlined and measures that can be taken to mitigate the risk are discussed. Ultimately, for crustacean diseases, the paradigm under which the OIE has operated for the past 80 years needs to change. PMID:22434004

Jones, Brian

2012-06-01

436

Effect of naphthalene and phenanthrene on the grass shrimp palaemonetes pugio (Holthuis)  

E-print Network

' d ftddl . * 1 I! ~1". I i mercury (Vernberg and 7ernberg, 1972) and cadmium (0'Hara, 1973), porcelain crabs petrolisthes armatus exposed to mercury (Roesijadi et al. , 1974), juvenile pink shrimp Penaeus duorarum e . Posed 'to polychlorinated...

Young, Gene Paul

1977-01-01

437

HISTOPATHOLOGICAL CHANGES IN GRASS SHRIMP EXPOSED TO CHROMIUM, PENTACHLOROPHENOL AND DITHIOCARBAMATES  

EPA Science Inventory

This report deals with the histopathological/ultrastructural changes in various tissues of grass shrimp (Palaemonetes pugio) exposed to hexavalent chromium, pentachlorophenol (PCP) and two dithiocarbamate formulations: Aquatreat DNM-30 (15% sodium dimethyl dithiocarbamate plus 15...

438

Productivity and Profitability of South Carolina Shrimp Vessels, 1971-75  

E-print Network

, the productivity of conven- tional capital (i.e., nonlabor capital) and human capital (i.e., labor) were estimtated.l that shrimping labor is earning less than its opportunity income. as is new capital investment, hut

439

Science Sampler: Bringing scientific inquiry alive using real grass shrimp research  

NSDL National Science Digital Library

This lesson was developed for middle school students using actual research on grass shrimp ( Palaemonetes pugio ) to illustrate the process of a scientific investigation. The research was conducted at Savannah State University and funded by the Nat

Curran, Mary C.; Partridge, Michael; Aultman, Terry

2010-03-01

440

Little Shrimp, Big Results: A Model of an Integrative, Cross-Curricular Activity  

NSDL National Science Digital Library

This integrative, cross-curricular lab engages middle school biology students in an exercise involving ecology, arthropod biology, and mathematics. Students research the anatomy and behavioral patterns of a species of brine shrimp, compare the anatomy of

Piser, Carol; Walka, Keith; Ackerson, Nicole

2010-12-01

441

75 FR 42070 - Certain Frozen Warmwater Shrimp from the People's Republic of China: Partial Rescission of...  

Federal Register 2010, 2011, 2012, 2013

...Action Committee (``AHSTAC'') is the petitioner in the underlying investigation. The members of AHSTAC are: Nancy Edens; Papa Rod, Inc., Carolina Seafoods; Bosarge Boats, Inc.; Knight's Seafood Inc.; Big Grapes, Inc.; Versaggi Shrimp...

2010-07-20

442

The American brine shrimp as an exotic invasive species in the western Mediterranean  

E-print Network

The American brine shrimp as an exotic invasive species in the western Mediterranean Francisco Amat March 2004 Key words: Artemia, aquaculture, salterns, western Mediterranean Abstract The hypersaline environments and salterns present in the western Mediterranean region (including Italy, southern France

Green, Andy J.

443

Does dinoflagellate bioluminescence deter shrimp grazing? An investigation into the Burglar Alarm Hypothesis  

E-print Network

). Investigations into some bioluminescent fungi and bacteria support this hypothesis; there is evidence;4 lignin (Lingle 1993). Similarly, in bacteria, bioluminescence has been linked to oxidation reactions1 Does dinoflagellate bioluminescence deter shrimp grazing? An investigation into the Burglar Alarm

444

50 CFR Figures 19a and 19b to Part... - Chauvin Shrimp Deflector Installation Details  

Code of Federal Regulations, 2012 CFR

50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Chauvin Shrimp Deflector Installation Details 19a Figures 19a and 19b to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL...

2012-10-01

445

50 CFR Figures 19a and 19b to Part... - Chauvin Shrimp Deflector Installation Details  

Code of Federal Regulations, 2013 CFR

50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Chauvin Shrimp Deflector Installation Details 19a Figures 19a and 19b to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL...

2013-10-01

446

78 FR 11221 - Frozen Warmwater Shrimp From China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam  

Federal Register 2010, 2011, 2012, 2013

...Shrimp From China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam Determination...imports from China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam of...Governments of China, Ecuador, India, Indonesia, Malaysia, Thailand, and...

2013-02-15

447

78 FR 764 - Frozen Warmwater Shrimp From China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam...  

Federal Register 2010, 2011, 2012, 2013

...Shrimp From China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam...imports from China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam of...Governments of China, Ecuador, India, Indonesia, Malaysia, Thailand, and...

2013-01-04

448

78 FR 50110 - Frozen Warmwater Shrimp From China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam...  

Federal Register 2010, 2011, 2012, 2013

...INTERNATIONAL TRADE COMMISSION [Inv. Nos. 701-TA-491-497 (Final)] Frozen Warmwater Shrimp From China, Ecuador, India, Indonesia, Malaysia, Thailand, and Vietnam; Commission Determination To Deny a Request To Hold a Portion of a Hearing In...

2013-08-16

449

U.S. southeastern shrimp and reef fish resources and their management  

E-print Network

gear types. Five hundred forty-eight sea turtle captures were documented aboard commercial shrimp vessels from 1992 through 2005. Ratio estimation reflected higher catch rates in nets not equipped with turtle excluder devices (TEDs). Two alternative...

Scott-Denton, Elizabeth

2009-05-15

450

Feeding hermit crabs to shrimp broodstock increases their risk of WSSV infection.  

PubMed

White spot syndrome virus (WSSV) is a serious shrimp pathogen that has spread globally to all major shrimp farming areas, causing enormous economic losses. Here we investigate the role of hermit crabs in transmitting WSSV to Penaeus monodon brooders used in hatcheries in Vietnam. WSSV-free brooders became PCR-positive for WSSV within 2 to 14 d, and the source of infection was traced to hermit crabs being used as live feed. Challenging hermit crabs with WSSV confirmed their susceptibility to infection, but they remained tolerant to disease even at virus loads equivalent to those causing acute disease in shrimp. As PCR screening also suggests that WSSV infection occurs commonly in hermit crab populations in both Vietnam and Taiwan, their use as live feed for shrimp brooders is not recommended. PMID:22535869

Chang, Yun-Shiang; Liu, Wang-Jing; Chen, Tsan-Chi; Chan, Tin-Yam; Liu, Kuan-Fu; Chuang, Jie-Cheng; Kou, Guang-Hsiung; Lo, Chu-Fang; Wang, Han-Ching

2012-04-26

451

Use of a Brine Shrimp Assay to Study Herbal Teas in the Classroom.  

ERIC Educational Resources Information Center

Introduces a brine shrimp assay to demonstrate the effects of the biological activity of herbal remedies. Describes two protocols, one using aqueous extracts and the other using methanol extracts. (Contains 21 references.) (YDS)

Opler, Annette; Mizell, Rebecca; Robert, Alexander; Cervantes-Cervantes, Miguel; Kincaid, Dwight; Kennelly, Edward J.

2002-01-01

452

Bioaccumulation of cyanuric acid in edible tissues of shrimp following experimental feeding.  

PubMed

Due to concerns that cyanuric acid (CYA)-contaminated feed had been used in aquaculture and could enter the human food chain, a method to quantify CYA residues in the edible tissues of fish and shrimp was previously developed and validated. This paper provides further data on the deliberate feeding of CYA to shrimp to determine the extent of residue accumulation in edible tissue. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the analysis of CYA in shrimp tissue. Edible tissue of shrimp fed 1666 or 3333 mg kg?¹ CYA in their diet (approximately 55 and 124 mg kg?¹ body weight) contained 0.767 and 0.406 mg kg?¹ CYA, respectively. The residue levels are below the World Health Organization (WHO) tolerable daily intake level for CYA and are generally considered unlikely to pose a human health risk. PMID:20936555

Karbiwnyk, Christine M; Williams, Rodney R; Andersen, Wendy C; Turnipseed, Sherri B; Madson, Mark R; Miller, Keith E; Reimschuessel, Renate

2010-12-01

453

78 FR 15686 - Certain Frozen Warmwater Shrimp From Thailand: Preliminary Results of Antidumping Duty...  

Federal Register 2010, 2011, 2012, 2013

...Department selected for individual examination are Marine Gold Products Limited (Marine Gold), and Thai Union Frozen Products Public Co...shrimp from Thailand produced and exported by Marine Gold. Finally, the Department also preliminarily...

2013-03-12

454

ASPECTS OF BROWN SHRIMP, PENAEUS AZTECUS, GROWTH IN THE NORTHERN GULF OF MEXICO  

E-print Network

importance of brown shrimp, Penaeus aztecus (Ives 1891), has precipitated sev- eral studies of the growth rate for individuals of that species. Definition ofthe growth rate is neces- sary in order to develop

455

50 CFR 654.24 - Shrimp/stone crab separation zones.  

Code of Federal Regulations, 2010 CFR

...AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE STONE CRAB FISHERY OF THE GULF OF MEXICO Management Measures § 654.24 Shrimp/stone crab separation zones. Five zones are established in the...

2010-10-01

456

50 CFR 654.24 - Shrimp/stone crab separation zones.  

Code of Federal Regulations, 2011 CFR

...AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE STONE CRAB FISHERY OF THE GULF OF MEXICO Management Measures § 654.24 Shrimp/stone crab separation zones. Five zones are established in the...

2011-10-01

457

21 CFR 161.173 - Canned wet pack shrimp in transparent or nontransparent containers.  

Code of Federal Regulations, 2010 CFR

...this chapter. (6) Sampling and acceptance procedure. A lot...defectives does not exceed the acceptance number in the sampling plans given in paragraph...of the shrimp. (2) Sampling and acceptance procedure: A...

2010-04-01

458

Genetic characterization of the burrowing shrimp (Neotrypaea californiensis) in Washington and Oregon estuaries  

EPA Science Inventory

The Ghost shrimp, (Neotrypaea californiensis) are burrowers, which have a wide demographic distribution along the United States Pacific Coast. Our study used genetic analysis to estimate the source populations of larvae recruiting into estuaries to allow a greater understanding ...

459

Seizing a species : the story of the Great Salt Lake brine shrimp harvest  

E-print Network

In the early 1950s, C.C. "Sparkplug" Sanders began harvesting brine shrimp from Utah's Great Salt Lake. Sanders built up a small business selling their eggs, called "cysts, to aquarium stores across the country. During the ...

Wotipka, Samuel Alex

2014-01-01

460

A real-time PCR for the detection of infectious myonecrosis virus in penaeid shrimp.  

PubMed

Infectious myonecrosis virus (IMNV) is a recently observed shrimp virus, which threats the cultured Litopenaeus vannamei and can cause huge economic loss in shrimp farming industry. The specific aim of this study was to develop a new sensitive real-time PCR method for the specific detection of shrimp IMNV. A real-time PCR assay with a pair of primers to specifically amplify a 101bp IMNV cDNA fragment and a corresponding TaqMan probe was developed, which shown to be specific for IMNV without cross reaction with DNA samples prepared from four other shrimp viruses including white spot syndrome virus (WSSV), hepatopancreatic parvovirus (HPV), monodon baculovirus (MBV), and infectious hypodermal and haematopoietic virus (IHHNV). The method could detect as low as one single copy of IMNV plasmid cDNA. PMID:23639336

Liu, Hong-Ling; Yan, Dong-Chun; Sun, Hu-Shan; Wang, Yi-Yan; Wang, Lei

2013-07-01

461

Requirements of shrimp, Penaeus chinensis O'sbeck for potassium, sodium, magnesium and iodine  

NASA Astrophysics Data System (ADS)

Potassium, sodium, magnesium and iodine requirements of shrimp, Penaeus chinensis were studied. Orthogonal design was employed in this experiment. The composition of the basal diet consisted of fish meal, peanut cake, corn meal, soybean cake, wheat bran, vitamin mix and mineral mix, and supplementations of potassium, sodium, magnesium and iodine in the basal diet were made according to the L9(34) orthogonal table. The results indicated that iodine supplementation improved growth of the shrimp significantly and raised survival very significantly, iodine requirement of the shrimp was 0.003%; sodium requirement was 0.87% or less; and that 1.1 1.3% potassium and 0.18 0.38% magnesium in the diet were proper nutrition supplements for the shrimp.

Liu, Fa-Yi; Li, He-Fang; Wang, Hui-Liang; Liang, De-Hai; Tian, Yu-Chuan

1995-06-01

462

Two Centuries of Observing R Coronae Borealis. What Will the Role of the AAVSO be in the Next Century?  

NASA Astrophysics Data System (ADS)

(Abstract only) R Coronae Borealis was found to be variable in the year 1783, and was one of the first variable stars to be identified. Its class, the R Coronae Borealis (RCB) stars, are rare hydrogen-deficient carbon-rich supergiants. RCB stars undergo massive declines of up to 8 mag due to the formation of carbon dust at irregular intervals. Their rarity may stem from the fact that they are in an extremely rapid phase of the evolution or in an evolutionary phase that most stars do not undergo. Several evolutionary scenarios have been suggested to account for the RCB stars including, a merger of two white dwarfs (WDs), or a final helium shell flash in a PN central star. The large overabundance of the rare isotope, oxygen-18, found in most of the RCB stars favors the WD merger scenario while the presence of Lithium in the atmospheres of five of the RCB stars favors the FF scenario. In particular, the measured isotopic abundances imply that many, if not most, RCB stars are produced by WD mergers, which may be the low-mass counterparts of the more massive mergers thought to produce type Ia supernovae. Understanding these enigmatic stars depends to a large extent on continuous monitoring to catch their irregular but rapid variations due to dust formation, their variations due to stellar pulsations, and longterm changes that may occur over centuries. The AAVSO has been instrumental in this monitoring for over a century, but how will this change in the era of all-sky surveys?

Clayton, G. C.

2014-06-01

463

Distribution, relative abundance and species composition of shrimp, crabs and fish in the intake area, discharge canal and cooling lake of the Cedar Bayou generating station, Baytown, Texas  

E-print Network

frequencies by date and station of brown shrimp caught by trawl (one square = one shrimp; stations 1-8 = cooling lake, 11-12 = intake area, 12-13 = discharge canal). Length frequencies by date and station of brown shrimp caught by seine (one square = one... shrimp; stations 9-10 = cooling lake, 11-12 = intake area) Length frequencies by date and station of white shrimp caught by trawl (one square = one shrimp; stations 1-8 = cooling lake, 11-12 = intake area, 13-14 = discharge canal) . Length frequencies...

St. Clair, Lou Ann

1978-01-01

464

Assimilation and subcellular partitioning of elements by grass shrimp collected along an impact gradient.  

PubMed

Chronic exposure to polluted field conditions can impact metal bioavailability in prey and may influence metal transfer to predators. The present study investigated the assimilation of Cd, Hg and organic carbon by grass shrimp Palaemonetes pugio, collected along an impact gradient within the New York/New Jersey Harbor Estuary. Adult shrimp were collected from five Staten Island, New York study sites, fed (109)Cd- or (203)Hg-labeled amphipods or (14)C-labeled meals and analyzed for assimilation efficiencies (AE). Subsamples of amphipods and shrimp were subjected to subcellular fractionation to isolate metal associated with a compartment presumed to contain trophically available metal (TAM) (metal associated with heat-stable proteins [HSP - e.g., metallothionein-like proteins], heat-denatured proteins [HDP - e.g., enzymes] and organelles [ORG]). TAM-(109)Cd% and TAM-(203)Hg% in radiolabeled amphipods were approximately 64% and approximately 73%, respectively. Gradients in AE-(109)Cd% ( approximately 54% to approximately 75%) and AE-(203)Hg% ( approximately 61% to approximately 78%) were observed for grass shrimp, with the highest values exhibited by shrimp collected from sites within the heavily polluted Arthur Kill complex. Population differences in AE-(14)C% were not observed. Assimilated (109)Cd% partitioned to the TAM compartment in grass shrimp varied between approximately 67% and approximately 75%. (109)Cd bound to HSP in shrimp varied between approximately 15% and approximately 47%, while (109)Cd associated with metal-sensitive HDP was approximately 17% to approximately 44%. Percentages of assimilated (109)Cd bound to ORG were constant at approximately 10%. Assimilated (203)Hg% associated with TAM in grass shrimp did not exhibit significant variation. Percentages of assimilated (203)Hg bound to HDP ( approximately 47%) and ORG ( approximately 11%) did not vary among populations and partitioning of (203)Hg to HSP was not observed. Using a simplified biokinetic model of metal accumulation from the diet, it is estimated that site-specific variability in Cd AE by shrimp and tissue Cd burdens in field-collected prey (polychaetes Nereis spp.) could potentially result in up to approximately 3.2-fold differences in the dose of Cd assimilated by shrimp from a meal in the field. The results of this study also suggest that chronic field exposure can impact mechanisms of metal transport across the gut epithelium that do not influence carbon assimilation. Differences in the assimilation and subcellular partitioning of metal may have important implications for metal toxicity in impacted shrimp populations. PMID:19473712

Seebaugh, David R; Wallace, William G

2009-06-28

465

Intraspecific variation in the marine shrimps Penaeus (Litopenaeus) stylirostris and Penaeus (Litopenaeus) vannamei  

E-print Network

INTRASPECIFIC VARIATION IN THE MARINE SHRIMPS PENAEUS (LITOPENAEUS) STYLIROSTRIS PENAEUS (LITOPENAEUS) VANNAMEI A Thesis by SCOTT EDWARD HORTON Submitted to the Graduate College of Texas A&M University in partial fulfillment... HORTON Approved as to style and content by: Davi J Sc mi y, S Chairma of Committe ison L. awrence, nda H. Pequegna , 0 Ho ce R. ur e, Ent Wa ace ussman, WFS Head of Department December 1981 ABSTRACT INTRASPECIFIC VARIATION IN THE MARINE SHRIMPS...

Horton, Scott Edward

2012-06-07

466

Genome-wide discovery of novel and conserved microRNAs in white shrimp (Litopenaeus vannamei).  

PubMed

Of late years, a large amount of conserved and species-specific microRNAs (miRNAs) have been performed on identification from species which are economically important but lack a full genome sequence. In this study, Solexa deep sequencing and cross-species miRNA microarray were used to detect miRNAs in white shrimp. We identified 239 conserved miRNAs, 14 miRNA* sequences and 20 novel miRNAs by bioinformatics analysis from 7,561,406 high-quality reads representing 325,370 distinct sequences. The all 20 novel miRNAs were species-specific in white shrimp and not homologous in other species. Using the conserved miRNAs from the miRBase database as a query set to search for homologs from shrimp expressed sequence tags (ESTs), 32 conserved computationally predicted miRNAs were discovered in shrimp. In addition, using microarray analysis in the shrimp fed with Panax ginseng polysaccharide complex, 151 conserved miRNAs were identified, 18 of which were significant up-expression, while 49 miRNAs were significant down-expression. In particular, qRT-PCR analysis was also performed for nine miRNAs in three shrimp tissues such as muscle, gill and hepatopancreas. Results showed that these miRNAs expression are tissue specific. Combining results of the three methods, we detected 20 novel and 394 conserved miRNAs. Verification with quantitative reverse transcription (qRT-PCR) and Northern blot showed a high confidentiality of data. The study provides the first comprehensive specific miRNA profile of white shrimp, which includes useful information for future investigations into the function of miRNAs in regulation of shrimp development and immunology. PMID:25227525

Xi, Qian-Yun; Xiong, Yuan-Yan; Wang, Yuan-Mei; Cheng, Xiao; Qi, Qi-En; Shu, Gang; Wang, Song-Bo; Wang, Li-Na; Gao, Ping; Zhu, Xiao-Tong; Jiang, Qing-Yan; Zhang, Yong-Liang; Liu, Li

2015-01-01

467

Electrical Conductivity of Frozen Shrimp and Flounder at Different Temperatures and Voltage Levels  

Microsoft Academic Search

Electrical conductivity (EC) is an important property during ohmic thawing of seafood. EC of frozen flounder, tiger and white shrimp, and shrimp shells at different voltages and temperatures (T) was measured. The materials were homogenized in a blender. PVC tubes (lengths: 4.1 to 5.6 cm, diameter: 1.5 cm) were filled with the material and fitted with circular stainless steel electrodes

Diego A. Luzuriaga; Murat O. Balaban

1996-01-01

468

Effects of a probiotic bacterium on black tiger shrimp Penaeus monodon survival and growth  

Microsoft Academic Search

Bacillus S11 bacterium isolated from black tiger shrimp habitats was added to shrimp feed as a probiotic in three forms: fresh cells, fresh cells in normal saline solution, and a lyophilized form. After a 100-day feeding trial with probiotic supplemented and non-supplemented (control) feeds, Penaeus monodon (from PL30) exhibited no significant difference (p>0.05) in growth, survival nor external appearance between

Sirirat Rengpipat; Wannipa Phianphak; Somkiat Piyatiratitivorakul; Piamsak Menasveta

1998-01-01

469

The effect of light intensity on the growth of Chinese shrimp Fenneropenaeus chinensis  

Microsoft Academic Search

The specific growth rate (SGRd) of juvenile Fenneropenaeus chinensis shrimp was measured over 35 days under different light intensities: 0, 50, 300, 1300 and 5500 lx. The SGRd of the shrimp under 5500 lx was only 29.4%, 27.1%, 21.1% and 19.7% of those under 0, 1300, 50 and 300 lx, respectively (P<0.05). The maximal and minimal feed intake (FId) of

Fang Wang; Shuanglin Dong; Shaoshuai Dong; Guoqiang Huang; Changbo Zhu; Yingchun Mu

2004-01-01

470

Effects of ghost shrimp on zinc and cadmium in sediments from Tampa Bay, FL  

USGS Publications Warehouse

This study investigated the effects that ghost shrimp have on the distribution of metals in sediment. We measured levels of HNO3-extractable zinc and cadmium in surface sediment, in ghost shrimp burrow walls and in sediment ejected by the ghost shrimp from their burrows, at five sandy intertidal sites in Tampa Bay. Ghost shrimp densities and their rate of sediment ejection were also quantified, as were sediment organic content and silt + clay content. Densities of ghost shrimp (Sergio trilobata and Lepidophthalmus louisianensis) averaged 33/m2 at our sites, and they ejected sediment at an average rate of 28 g/burrow/day. Levels of both Zn and Cd were significantly higher in burrow walls than in surface sediments. Sediment ejected by the shrimp from their burrows had elevated levels of Zn (relative to surface sediments) at one of the sites. Sediment organic content and silt + clay content were higher in burrow-wall sediments than in ejected sediment, which in turn tended to have values above those of surface sediments. Differences in levels of HNO3-extractable Zn and Cd among sediment types may be a consequence of these sediments differing in other physiochemical characteristics, though the differences in metal levels remained statistically significant for some sites after correcting for differences in organic content and silt + clay content. We conclude that the presence of ghost shrimp burrows contributes to spatial heterogeneity of sedimentary metal levels, while the ghost shrimp bioturbation results in a significant flux of metals to the sediment surface and is expected to decrease heterogeneity of metal levels in sedimentary depth profiles.

Klerks, P.L.; Felder, D.L.; Strasser, K.; Swarzenski, P.W.

2007-01-01

471

Morphological stasis and phylogenetic relationships in Tadpole shrimps, Triops (Crustacea: Notostraca)  

Microsoft Academic Search

The tadpole shrimp (Triops) is a well-known ‘living fossil’ whose fundamental morphology has been unchanged for over 170 million years. Thus, tadpole shrimps are suitable subjects for the study of morphological stasis. We were able to obtain samples of three species ofTriops(T. granarius, T. longicaudatusandT. cancriformis) from four regions in Japan. Taxonomic species were identified by diagnostic morphology. We inferred

NOBUMITSU SUNO-UCHI; FUMIYO SASAKI; SATOSHI CHIBA; MASAKADO KAWATA

1997-01-01

472

[Bacterial community structure in intestine of the white shrimp, Litopenaeus vannamei].  

PubMed

The composition of bacterial community in the intestine of the white shrimp, Litopenaeus vannamei under laboratory culture condition was determined using the 16S rDNA clone library. 16s rRNA gene was amplified and a library was constructed by using the genomic DNA extracted from the bacteria in the shrimp intestine as template. 12 different RFLP patterns of the clones were obtained by restriction fragment length polymorphism analysis using Afa I and Msp I. Compared with the published sequences in GenBank database, sequencing results of cloned 16S rDNA amplicons revealed a diverse community including gamma-proteobacteria and Firmicutes in the intestine of artificial diet-fed shrimp. Results showed that the Firmicutes group can be a dominant component (75.4%) in the shrimp intestinal microflora and other clones belong to gamma-proteobacteria (24.6%) which were identified as Shewanella sp., Pantoea sp., Aranicola sp., Pseudomonas sp. and Vibrio sp., respectively. These results provide the first comprehensive description of microbial diversity of the white shrimp intestine and suggest that most of the bacteria associated with shrimp intestine are uncultured and novel species. PMID:17944366

Li, Ke; Zheng, Tian-ling; Tian, Yun; Yuan, Jian-jun

2007-08-01

473

Pulsed Ultraviolet Light Reduces Immunoglobulin E Binding to Atlantic White Shrimp (Litopenaeus setiferus) Extract  

PubMed Central

Pulsed ultraviolet light (PUV), a novel food processing and preservation technology, has been shown to reduce allergen levels in peanut and soybean samples. In this study, the efficacy of using PUV to reduce the reactivity of the major shrimp allergen, tropomyosin (36-kDa), and to attenuate immunoglobulin E (IgE) binding to shrimp extract was examined. Atlantic white shrimp (Litopenaeus setiferus) extract was treated with PUV (3 pulses/s, 10 cm from light source) for 4 min. Tropomyosin was compared in the untreated, boiled, PUV-treated and [boiled+PUV]-treated samples, and changes in the tropomyosin levels were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). IgE binding of the treated extract was analyzed via immunoblot and enzyme-linked immunosorbent assay (ELISA) using pooled human plasma containing IgE antibodies against shrimp allergens. Results showed that levels of tropomyosin and IgE binding were reduced following PUV treatment. However, boiling increased IgE binding, while PUV treatment could offset the increased allergen reactivity caused by boiling. In conclusion, PUV treatment reduced the reactivity of the major shrimp allergen, tropomyosin, and decreased the IgE binding capacity of the shrimp extract. PMID:21845146

Shriver, Sandra; Yang, Wade; Chung, Si-Yin; Percival, Susan

2011-01-01

474

Effects of three Caribbean cleaner shrimps on ectoparasitic monogeneans in a semi-natural environment  

NASA Astrophysics Data System (ADS)

Most research on cleaning symbioses on coral reefs has focused on fish clients being cleaned by smaller fishes. While many shrimps and other crustaceans are reported as cleaners, whether they remove parasites from fish hosts and can effectively regulate populations of ectoparasites is unclear. The effects of Pederson shrimp ( Periclimenes pedersoni) , spotted shrimp ( P. yucatanicus), and banded coral shrimp ( Stenopus hispidus), on the parasitic monogenean Neobenedenia melleni on a host reef fish, blue tang ( Acanthurus coeruleus), were investigated. The abundance and size of N. melleni from fish with and without access to shrimps in a semi-natural macrocosm was quantified. P. pedersoni had a strong effect on both the abundance and size of parasites. In contrast, P. yucatanicus and S. hispidus had no effect on the abundance of parasites but had a small yet statistically significant effect on average size. These data suggest that P. pedersoni can play a significant role in the biological regulation of at least some ectoparasites on Caribbean reef fishes, but further suggest that some other shrimps regarded as “cleaners” may have little or no effectiveness at removing parasites and underscore the need for further verification before this term is applied.

McCammon, A.; Sikkel, P. C.; Nemeth, D.

2010-06-01

475

Use of acidic electrolyzed water ice for preserving the quality of shrimp.  

PubMed

Electrolyzed water ice is a relatively new concept developed in food industry in recent years. The effect of acidic electrolyzed water (AEW) ice on preserving the quality of shrimp (Litopenaeus vannamei) was investigated. Physical, chemical, and microbiological changes of the shrimp were examined during the storage. The results showed that compared with tap water (TW) ice, AEW ice displayed a potential ability in limiting the pH changes of shrimp flesh and significantly (p < 0.05) retarded the changes of color difference and the formation of total volatile basic nitrogen (TVBN). And AEW ice treatment had no adverse effects on the firmness of shrimp. Conventional plate count enumeration and PCR-DGGE demonstrated that AEW ice had a capability of inhibiting growth of bacteria on raw shrimp, and the maximum reductions of population reached >1.0 log CFU/g (>90%) on the sixth day. Moreover, AEW ice was clearly more efficient in maintaining the initial attachments between muscle fibers in shrimp according to histological section analysis. On the basis of above analysis, AEW ice can be a new alternative of traditional sanitizer to better preserve the quality of seafood in the future. PMID:23947475

Lin, Ting; Wang, Jing Jing; Li, Ji Bing; Liao, Chao; Pan, Ying Jie; Zhao, Yong

2013-09-11

476

Effect of stocking density on extensive production of freshwater shrimp in coal mine reclamation ponds  

SciTech Connect

The use of post-mining reclamation ponds for the production of freshwater shrimp was evaluated by examining different stocking densities. Juvenile shrimp (Macrobrachium rosenbergii) averaging 0.5g each were stocked into four existing ponds at Peabody`s Ken Surface Mine at 6,175; 12,350; 18,500; and 24,700/ha (2,500, 5,000, 7,500, and 10,000/acre) on June 1, 1995. Shrimp were fed twice a week for 103 days, with harvest conducted September 13, 1995. Survival averaged 40%, overall. Average individual weight size was inversely related to stocking density ranging from 52 g (8.7 shrimp/lb) at 6,175/ha to 20.3 g (22.7 shrimp/lb) at 18,500/acre. Total production was directly related to stocking density ranging from 97 kg/ha (86 lbs/acre) at low density to 211 kg/ha (188 lbs/acre) at 18,500/ha shrimp acre. The major difficulty was at harvest due to difficulty in draining ponds. Construction of designed culture ponds with gravity drains during reclamation could greatly enhance survival, harvestability, and commercial feasibility.

Tidwell, J.H.; Wynne, F.; Coyle, S.D. [Kentucky State Univ., Frankfort, KY (United States). Aquaculture Research Center; Grey, B. [Peabody Coal Co., Rockport, KY (United States); McGuire, J.

1998-12-31

477

Effects of gamma irradiation on chemical, microbial quality and shelf life of shrimp  

NASA Astrophysics Data System (ADS)

In the present study the combined effect of gamma irradiation (1, 3 and 5 kGy) and storage at two temperatures: refrigeration (+4 °C) and frozen (-18 °C), on the shelf-life extension of fresh shrimp meat was investigated. The study was based on microbiological and physicochemical changes occuring in the shrimp samples. Total volatile base nitrogen values and trimethylamine values for irradiated shrimp samples were significantly lower than non-irradiated samples at both storage temperatures, and the rate of decrease was more pronounced in samples irradiated at the higher dose (p<0.05). Thiobarbituric acid values for irradiated shrimp samples were significantly higher than non-irradiated samples at both storage temperatures (p<0.05). pH values of shrimp samples were affected significantly by both irradiating dose and storage temperatures (p<0.05). Microbial counts for non-irradiated shrimp samples were higher than the respective irradiated samples at both storage temperatures (p<0.05). The results revealed that irradiation at high dose (5 kGy) might enhance lipid oxidation, although the growth of microorganisms and protein oxidation was inhibited.

Hocao?lu, Asl?; Sükrü Demirci, Ahmet; Gümüs, Tuncay; Demirci, Mehmet

2012-12-01

478

Inhibition of melanosis formation in Pacific white shrimp by the extract of lead (Leucaena leucocephala) seed.  

PubMed

Lead (Leucaena leucocephala) seed extract was prepared using distilled water as a medium. An extraction yield of 26.16g/100g of seed was obtained after extraction at room temperature for 12h. Total phenolic and mimosine contents in the lead seed extract powder (LSEP) were 17.4g GAE/100g and 8.8g/100g, respectively. LSEP at different concentrations (0.05%, 0.1%, 0.25%, 0.5%, and 1%, w/v) showed inhibitory activity towards polyphenoloxidase (PPO) of Pacific white shrimp in a dose dependent manner. When the whole Pacific white shrimp were treated with 0.25% and 0.5% (w/v) LSEP, the shrimp treated with 0.5% LSEP had the lower melanosis score throughout the storage of 12days and showed a higher score for colour and odour, as well as overall likeness, compared with the control (without treatment) and 1.25% sodium metabisulphite treated samples at day 12 (P<0.05). Meat of shrimps treated with LSEP at both levels had the increase in mimosine content up to 8days, suggesting the migration of mimosine into shrimp muscle during extended storage. Therefore, 0.5% LSEP can be used as a novel melanosis inhibitor for Pacific white shrimp. PMID:25212152

Nirmal, Nilesh Prakash; Benjakul, Soottawat

2011-09-15

479

Abundance and seasonal migrations of the penaeid shrimp Metapenaeus affinis (H. Milne-Edwards) within Iraqi waters  

Microsoft Academic Search

Migration of Metapenaeus affinis (H. Milne-Edwards) from the Arabian Gulf to nursery grounds in the inland waters of Iraq extends from May\\/June to January\\/February. Shrimp ranging in size from 3–125 mm total length were found in inland waters. In the shallow waters of the Al-Assaflya small-sized shrimp only were caught, while in the Marshes large-sized shrimp were abundant. Maximum numbers

S. D. Salman; M. H. Ali; A. H. Y. Al-AdhubI

1990-01-01

480

Impact of quinalphos on blood glucose and acetylcholinesterase (AChE) activity in brain and pancreas in a roseringed parakeet ( Psittacula krameri borealis: Newmann)  

Microsoft Academic Search

Quinalphos (O,O-diethyl O-2-quinoxalinyl phosphorothioate), an organophosphate pesticide, was orally administered in graded sublethal doses (5 µg-, 10 µg- and 20 µg\\/ 100 g body mass\\/day) for 10 consecutive days to study the effects on the levels of blood glucose, liver- and muscle-glycogen, and acetylcholinesterase (AChE) activity in the brain and pancreas of adult male Roseringed parakeets (Psittacula krameri borealis). Orally

K. K. Anam; S. K. Maitra

1995-01-01

481

The Fall and Rise of V854 Centauri: Long-Term Ultraviolet Spectroscopy of a Highly Active R Coronae Borealis Star  

Microsoft Academic Search

We examine long-term low-dispersion International Ultraviolet Explorer SWP and LWP spectroscopy of the R Coronae Borealis (RCB) star V854 Cen, obtained across the deep (DeltaV>6 mag) 1991, 1992-1993, and 1994 declines. We also report the optical light curve for the star in the interval 1987-1998, including multicolor photometry obtained during 1989-1998. The light curve includes at least eight major declines

Warrick A. Lawson; Marco M. Maldoni; Geoffrey C. Clayton; Lynne Valencic; Albert F. Jones; David Kilkenny; Francois van Wyk; Greg Roberts; Fred Marang

1999-01-01

482

Very Large Excesses of 18O in Hydrogen-deficient Carbon and R Coronae Borealis Stars: Evidence for White Dwarf Mergers  

Microsoft Academic Search

We have found that at least seven hydrogen-deficient carbon (HdC) and R Coronae Borealis (RCB) stars, have 16O\\/18O ratios close to and in some cases less than unity, values that are orders of magnitude lower than measured in other stars (the solar value is 500). Greatly enhanced 18O is evident in every HdC and RCB we have measured that is

Geoffrey C. Clayton; T. R. Geballe; Falk Herwig; Christopher Fryer; Martin Asplund

2007-01-01

483

Radio, X?Ray, and Extreme?Ultraviolet Coronal Variability of the Short?Period RS Canum Venaticorum Binary ? 2 Coronae Borealis  

Microsoft Academic Search

We present the results of a coordinated observing campaign on the short-period (1.14 days) RS CVn binary p2 Coronae Borealis with the VLA, ASCA, and RXT E. We also discuss earlier observations of the same system obtained by the Extreme Ultraviolet Explorer (EUV E). Dramatic coronal variability is present in all of these observations across the electromagnetic spectrum. p2 CrB

Rachel A. Osten; Alexander Brown; Thomas R. Ayres; Jeffrey L. Linsky; Stephen A. Drake; Marc Gagne; Robert A. Stern

2000-01-01

484

A different form of color vision in mantis shrimp.  

PubMed

One of the most complex eyes in the animal kingdom can be found in species of stomatopod crustaceans (mantis shrimp), some of which have 12 different photoreceptor types, each sampling a narrow set of wavelengths ranging from deep ultraviolet to far red (300 to 720 nanometers). Functionally, this chromatic complexity has presented a mystery. Why use 12 color channels when three or four are sufficient for fine color discrimination? Behavioral wavelength discrimination tests (?? functions) in stomatopods revealed a surprisingly poor performance, ruling out color vision that makes use of the conventional color-opponent coding system. Instead, our experiments suggest that stomatopods use a previously unknown color vision system based on temporal signaling combined with scanning eye movements, enabling a type of color recognition rather than discrimination. PMID:24458639

Thoen, Hanne H; How, Martin J; Chiou, Tsyr-Huei; Marshall, Justin

2014-01-24

485

Cation-dependent nutrient transport in shrimp digestive tract.  

PubMed

Purified epithelial brush border membrane vesicles (BBMV) were produced from the hepatopancreas of the Atlantic White shrimp, Litopeneaus setiferus, using standard methods originally developed for mammalian tissues and previously applied to other crustacean and echinoderm epithelia. These vesicles were used to study the cation dependency of sugar and amino acid transport across luminal membranes of hepatopancreatic epithelial cells. (3)H-D: -glucose uptake by BBMV against transient sugar concentration gradients occurred when either transmembrane sodium or potassium gradients were the only driving forces for sugar accumulation, suggesting the presence of a possible coupled transport system capable of using either cation. (3)H-L: -histidine transport was only stimulated by a transmembrane potassium gradient, while (3)H-L: -leucine uptake was enhanced by either a sodium or potassium gradient. These responses suggest the possible presence of a potassium-dependent transporter that accommodates either amino acid and a sodium-dependent system restricted only to L: -leucine. Uptake of (3)H-L: -leucine was significantly stimulated (P < 0.05) by several metallic cations (e.g., Zn(2+), Cu(2+), Mn(2+), Cd(2+), or Co(2+)) at external pH values of 7.0 or 5.0 (internal pH 7.0), suggesting a potential synergistic role of the cations in the transmembrane transfer of amino acids. (3)H-L: -histidine influxes (15 suptakes) were hyperbolic functions of external [zinc] or [manganese], following Michaelis-Menten kinetics. The apparent affinity constant (e.g., K (m)) for manganese was an order of magnitude smaller (K (m) = 0.22 ?M Mn) than that for zinc (K (m) = 1.80 ?M Zn), while no significant difference (P > 0.05) occurred between their maximal transport velocities (e.g., J (max)). These results suggest that a number of cation-dependent nutrient transport systems occur on the shrimp brush border membrane and aid in the absorption of these important dietary elements. PMID:21983793

Simmons, Tamla; Mozo, Julie; Wilson, Jennifer; Ahearn, Gregory A

2012-02-01

486

Dietary effect of Rubus coreanus ethanolic extract on immune gene expression in white leg shrimp, Penaeus vannamei.  

PubMed

The objective of this study was to evaluate the effect of dietary supplementation of a Rubus coreanus ethanolic extract on immunostimulatory response in white leg shrimp Penaeus vannamei. Shrimps with an average initial weight of 0.5 ± 0.04 g were collected and acclimatized for 10 days. Four experimental diets including a control diet, a probiotic diet and 0.25 and 0.5% of R. coreanus ethanolic extract (RcEE) diets were used to feed the shrimps. After 8 weeks of culture, shrimp fed with probiotic and 0.25% RcEE diet had showed significant enhancement in the growth while shrimp fed with 0.5% RcEE diet showed significantly increased expression of immune genes and antioxidant enzymes activities. One week of challenge experiments for all the four diets fed shrimps showed decreased cumulative mortality in the 0.5% RcEE diets fed shrimps, when compared with the probiotic and 0.25% RcEE diet fed shrimp groups. The results indicates that R. coreanus ethanolic extract could be used as a herbal immunostimulant for shrimps to increase its immunity and disease resistance against the bacterial pathogen, Vibrio alginolyticus. PMID:23811352

Subramanian, Dharaneedharan; Jang, Yeoung-Hwan; Kim, Dong-Hwi; Kang, Bong-Jo; Heo, Moon-Soo

2013-09-01

487

DNaseI-hypersensitive sites at promoter-like sequences in the spacer of Xenopus laevis and Xenopus borealis ribosomal DNA.  

PubMed Central

We have detected a DNAseI hypersensitive site in the ribosomal DNA spacer of Xenopus laevis and Xenopus borealis. The site is present in blood and embryonic nuclei of each species. In interspecies hybrids, however, the site is absent in unexpressed borealis rDNA, but is present normally in expressed laevis rDNA. Hypersensitive sites are located well upstream (over lkb) of the pre-ribosomal RNA promoter. Sequencing of the hypersensitive region in borealis rDNA, however, shows extensive homology with the promoter sequence, and with the hypersensitive region in X. laevis. Of two promoter-like duplications in each spacer, only the most upstream copy is associated with hypersensitivity to DNAaseI. Unlike DNAaseI, Endo R. MspI digests the rDNA of laevis blood nuclei at a domain extending downstream from the hypersensitive site to near the 40S promoter. Since the organisation of conserved sequence elements within this "proximal domain" is similar in three Xenopus species whose spacers have otherwise evolved rapidly, we conclude that this domain plays an important role in rDNA function. Images PMID:6310495

La Volpe, A; Taggart, M; McStay, B; Bird, A

1983-01-01

488

LINKING HABITAT CHANGE AND NUTRIENT DYNAMICS: COMPARISON OF FOOD WEBS AND NITROGEN FLUXES IN BURROWING SHRIMP- AND OYSTER-DOMINATED HABITATS  

EPA Science Inventory

Endemic thalassinid burrowing shrimps are simultaneously dominant ecosystem engineering species and economic pests within Pacific estuaries. Dense populations of two shrimps (Neotrypaea californiensis and Upogebia pugettensis) commonly occupy >75% of intertidal and shallow subti...

489

Resistance to the crayfish plague pathogen, Aphanomyces astaci, in two freshwater shrimps.  

PubMed

Aphanomyces astaci, the causal agent of the crayfish plague, has recently been confirmed to infect also freshwater-inhabiting crabs. We experimentally tested the resistance of freshwater shrimps, another important decapod group inhabiting freshwaters, to this pathogen. We exposed individuals of two Asian shrimp species, Macrobrachium dayanum and Neocaridina davidi, to zoospores of the pathogen strain isolated from Procambarus clarkii, a known A. astaci carrier likely to get into contact with shrimps. The shrimps were kept in separate vessels up to seven weeks; exuviae and randomly chosen individuals were sampled throughout the experiment. Shrimp bodies and exuviae were tested for A. astaci presence by a species-specific quantitative PCR. The results were compared with amounts of A. astaci DNA in an inert substrate to distinguish potential pathogen growth in live specimens from persisting spores or environmental DNA attached to their surface. In contrast to susceptible crayfish Astacus astacus, we did not observe mortality of shrimps. The amount of detected pathogen DNA was decreasing steadily in the inert substrate, but it was still detectable several weeks after zoospore addition, which should be considered in studies relying on molecular detection of A. astaci. Probably due to moulting, the amount of A. astaci DNA was decreasing in N. davidi even faster than in the inert substrate. In contrast, high pathogen DNA levels were detected in some non-moulting individuals of M. dayanum, suggesting that A. astaci growth may be possible in tissues of this species. Further experiments are needed to test for the potential of long-term A. astaci persistence in freshwater shrimp populations. PMID:25064254

Svoboda, J; Mruga?a, A; Kozubíková-Balcarová, E; Kouba, A; Diéguez-Uribeondo, J; Petrusek, A

2014-09-01