Science.gov

Sample records for act afa crab

  1. 50 CFR Table 41 to Part 679 - BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false BSAI Crab PSC Sideboard Limits for AFA...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 41 Table 41 to Part 679—BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels For the following crab species in...

  2. 50 CFR Table 41 to Part 679 - BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false BSAI Crab PSC Sideboard Limits for AFA...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 41 Table 41 to Part 679—BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels For the following crab species in...

  3. 50 CFR Table 41 to Part 679 - BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false BSAI Crab PSC Sideboard Limits for AFA...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 41 Table 41 to Part 679—BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels For the following crab species in...

  4. 50 CFR Table 41 to Part 679 - BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false BSAI Crab PSC Sideboard Limits for AFA...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 41 Table 41 to Part 679—BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels For the following crab species in...

  5. 50 CFR Table 41 to Part 679 - BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false BSAI Crab PSC Sideboard Limits for AFA...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 41 Table 41 to Part 679—BSAI Crab PSC Sideboard Limits for AFA Catcher/Processors and AFA Catcher Vessels For the following crab species in...

  6. 76 FR 59922 - Pacific Cod by Non-American Fisheries Act Crab Vessels Harvesting Pacific Cod for Processing by...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-28

    ... FR 11111, March 1, 2011). ] In accordance with Sec. 680.22(e)(2)(i), the Administrator, Alaska Region... Fisheries Act Crab Vessels Harvesting Pacific Cod for Processing by the Inshore Component in the Western... directed fishing for Pacific cod by non- American Fisheries Act (AFA) crab vessels that are subject...

  7. 76 FR 58414 - Pacific Cod by Non-American Fisheries Act Crab Vessels Harvesting Pacific Cod for Processing by...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... FR 11111, March 1, 2011). In accordance with Sec. 680.22(e)(2)(i), the Administrator, Alaska Region... Fisheries Act Crab Vessels Harvesting Pacific Cod for Processing by the Inshore Component in the Central... directed fishing for Pacific cod by non- American Fisheries Act (AFA) crab vessels that are subject...

  8. 25 CFR 1000.409 - Does the Prompt Payment Act (31 U.S.C. 3901) apply to a non-BIA, non-Indian program AFA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Does the Prompt Payment Act (31 U.S.C. 3901) apply to a..., INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT... § 1000.409 Does the Prompt Payment Act (31 U.S.C. 3901) apply to a non-BIA, non-Indian program AFA?...

  9. 76 FR 31941 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Horseshoe Crabs; Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-02

    ... Management Act Provisions; Horseshoe Crabs; Application for Exempted Fishing Permit AGENCY: National Marine... 10,000 horseshoe crabs from the Carl N. Shuster Jr. Horseshoe Crab Reserve (Reserve) for biomedical... crabs within the reserve. The Acting Director has also made a preliminary determination that...

  10. 75 FR 8841 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ... specifications for groundfish of the GOA (74 FR 7333, February 17, 2009) and inseason adjustment (74 FR 68713... Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act Crab Vessels Catching Pacific Cod for... Fisheries Act (AFA) crab vessels catching Pacific cod for processing by the offshore component in...

  11. 76 FR 4551 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... groundfish of the GOA (75 FR 11749, March 12, 2010) and inseason adjustment (76 FR 469, January 5, 2011). In... Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act Crab Vessels Harvesting Pacific Cod for... Fisheries Act (AFA) crab vessels that are subject to sideboard limits harvesting Pacific cod for...

  12. 76 FR 3045 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... FR 11749, March 12, 2010) and inseason adjustment (76 FR 469, January 5, 2011). In accordance with... Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act Crab Vessels Harvesting Pacific Cod for... Fisheries Act (AFA) crab vessels that are subject to sideboard limits harvesting Pacific cod for...

  13. 75 FR 7205 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-18

    ... groundfish of the GOA (74 FR 7333, February 17, 2009) and inseason adjustment (74 FR 68713, December 29, 2009... Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act Crab Vessels Catching Pacific Cod for... Fisheries Act (AFA) crab vessels catching Pacific cod for processing by the inshore component in the...

  14. 75 FR 3875 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... of the GOA (74 FR 7333, February 17, 2009) and inseason adjustment (74 FR 68713, December 29, 2009... Economic Zone Off Alaska; Pacific Cod by Non-American Fisheries Act Crab Vessels Catching Pacific Cod for... Fisheries Act (AFA) crab vessels catching Pacific cod for processing by the inshore component in the...

  15. 78 FR 29331 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Horseshoe Crabs; Application...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-20

    ... Register on September 10, 2012 (77 FR 55457), and thus are not repeated here. Data collected under previous... Management Act Provisions; Horseshoe Crabs; Application for Exempted Fishing Permit, 2013 AGENCY: National... 10,000 horseshoe crabs from the Carl N. Shuster Jr. Horseshoe Crab Reserve (Reserve) for...

  16. 25 CFR 1000.397 - Are there any restrictions on how AFA funds may be spent?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Are there any restrictions on how AFA funds may be spent... INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT Miscellaneous Provisions § 1000.397 Are there any restrictions on how AFA...

  17. 25 CFR 1000.397 - Are there any restrictions on how AFA funds may be spent?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Are there any restrictions on how AFA funds may be spent... INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT Miscellaneous Provisions § 1000.397 Are there any restrictions on how AFA...

  18. Pathogenesis of Human Diffusely Adhering Escherichia coli Expressing Afa/Dr Adhesins (Afa/Dr DAEC): Current Insights and Future Challenges

    PubMed Central

    2014-01-01

    SUMMARY The pathogenicity and clinical pertinence of diffusely adhering Escherichia coli expressing the Afa/Dr adhesins (Afa/Dr DAEC) in urinary tract infections (UTIs) and pregnancy complications are well established. In contrast, the implication of intestinal Afa/Dr DAEC in diarrhea is still under debate. These strains are age dependently involved in diarrhea in children, are apparently not involved in diarrhea in adults, and can also be asymptomatic intestinal microbiota strains in children and adult. This comprehensive review analyzes the epidemiology and diagnosis and highlights recent progress which has improved the understanding of Afa/Dr DAEC pathogenesis. Here, I summarize the roles of Afa/Dr DAEC virulence factors, including Afa/Dr adhesins, flagella, Sat toxin, and pks island products, in the development of specific mechanisms of pathogenicity. In intestinal epithelial polarized cells, the Afa/Dr adhesins trigger cell membrane receptor clustering and activation of the linked cell signaling pathways, promote structural and functional cell lesions and injuries in intestinal barrier, induce proinflammatory responses, create angiogenesis, instigate epithelial-mesenchymal transition-like events, and lead to pks-dependent DNA damage. UTI-associated Afa/Dr DAEC strains, following adhesin-membrane receptor cell interactions and activation of associated lipid raft-dependent cell signaling pathways, internalize in a microtubule-dependent manner within urinary tract epithelial cells, develop a particular intracellular lifestyle, and trigger a toxin-dependent cell detachment. In response to Afa/Dr DAEC infection, the host epithelial cells generate antibacterial defense responses. Finally, I discuss a hypothetical role of intestinal Afa/Dr DAEC strains that can act as “silent pathogens” with the capacity to emerge as “pathobionts” for the development of inflammatory bowel disease and intestinal carcinogenesis. PMID:25278576

  19. Factor C acts as a lipopolysaccharide-responsive C3 convertase in horseshoe crab complement activation.

    PubMed

    Ariki, Shigeru; Takahara, Shusaku; Shibata, Toshio; Fukuoka, Takaaki; Ozaki, Aya; Endo, Yuichi; Fujita, Teizo; Koshiba, Takumi; Kawabata, Shun-ichiro

    2008-12-01

    The complement system in vertebrates plays an important role in host defense against and clearance of invading microbes, in which complement component C3 plays an essential role in the opsonization of pathogens, whereas the molecular mechanism underlying C3 activation in invertebrates remains unknown. In an effort to understand the molecular activation mechanism of invertebrate C3, we isolated and characterized an ortholog of C3 (designated TtC3) from the horseshoe crab Tachypleus tridentatus. Flow cytometric analysis using an Ab against TtC3 revealed that the horseshoe crab complement system opsonizes both Gram-negative and Gram-positive bacteria. Evaluation of the ability of various pathogen-associated molecular patterns to promote the proteolytic conversion of TtC3 to TtC3b in hemocyanin-depleted plasma indicated that LPS, but not zymosan, peptidoglycan, or laminarin, strongly induces this conversion, highlighting the selective response of the complement system to LPS stimulation. Although originally characterized as an LPS-sensitive initiator of hemolymph coagulation stored within hemocytes, we identified factor C in hemolymph plasma. An anti-factor C Ab inhibited various LPS-induced phenomena, including plasma amidase activity, the proteolytic activation of TtC3, and the deposition of TtC3b on the surface of Gram-negative bacteria. Moreover, activated factor C present on the surface of Gram-negative bacteria directly catalyzed the proteolytic conversion of the purified TtC3, thereby promoting TtC3b deposition. We conclude that factor C acts as an LPS-responsive C3 convertase on the surface of invading Gram-negative bacteria in the initial phase of horseshoe crab complement activation.

  20. 25 CFR 1000.139 - Will the established indirect cost rates always apply to new AFAs?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Will the established indirect cost rates always apply to new AFAs? 1000.139 Section 1000.139 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT...

  1. 25 CFR 1000.139 - Will the established indirect cost rates always apply to new AFAs?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Will the established indirect cost rates always apply to new AFAs? 1000.139 Section 1000.139 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT...

  2. 76 FR 13593 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-14

    .... Vessels that meet these criteria subsequently will be referred to as ``non-AFA crab vessels.'' The CR... Bering Sea and Aleutian Islands Crab Rationalization Program (CR Program). Regulations implementing Amendments 18 and 19 were published on March 2, 2005 (70 FR 10174), and are located at 50 CFR part...

  3. Pathogenesis of Afa/Dr Diffusely Adhering Escherichia coli

    PubMed Central

    Servin, Alain L.

    2005-01-01

    Over the last few years, dramatic increases in our knowledge about diffusely adhering Escherichia coli (DAEC) pathogenesis have taken place. The typical class of DAEC includes E. coli strains harboring AfaE-I, AfaE-II, AfaE-III, AfaE-V, Dr, Dr-II, F1845, and NFA-I adhesins (Afa/Dr DAEC); these strains (i) have an identical genetic organization and (ii) allow binding to human decay-accelerating factor (DAF) (Afa/DrDAF subclass) or carcinoembryonic antigen (CEA) (Afa/DrCEA subclass). The atypical class of DAEC includes two subclasses of strains; the atypical subclass 1 includes E. coli strains that express AfaE-VII, AfaE-VIII, AAF-I, AAF-II, and AAF-III adhesins, which (i) have an identical genetic organization and (ii) do not bind to human DAF, and the atypical subclass 2 includes E. coli strains that harbor Afa/Dr adhesins or others adhesins promoting diffuse adhesion, together with pathogenicity islands such as the LEE pathogenicity island (DA-EPEC). In this review, the focus is on Afa/Dr DAEC strains that have been found to be associated with urinary tract infections and with enteric infection. The review aims to provide a broad overview and update of the virulence aspects of these intriguing pathogens. Epidemiological studies, diagnostic techniques, characteristic molecular features of Afa/Dr operons, and the respective role of Afa/Dr adhesins and invasins in pathogenesis are described. Following the recognition of membrane-bound receptors, including type IV collagen, DAF, CEACAM1, CEA, and CEACAM6, by Afa/Dr adhesins, activation of signal transduction pathways leads to structural and functional injuries at brush border and junctional domains and to proinflammatory responses in polarized intestinal cells. In addition, uropathogenic Afa/Dr DAEC strains, following recognition of β1 integrin as a receptor, enter epithelial cells by a zipper-like, raft- and microtubule-dependent mechanism. Finally, the presence of other, unknown virulence factors and the way that

  4. 25 CFR 1000.276 - Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA? 1000.276 Section 1000.276 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS...-governance AFA if FTCA is not referenced in the AFA? Yes, FTCA applies even if the AFA does not mention it....

  5. 25 CFR 1000.276 - Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA? 1000.276 Section 1000.276 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS...-governance AFA if FTCA is not referenced in the AFA? Yes, FTCA applies even if the AFA does not mention it....

  6. 25 CFR 1000.276 - Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA? 1000.276 Section 1000.276 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS...-governance AFA if FTCA is not referenced in the AFA? Yes, FTCA applies even if the AFA does not mention it....

  7. 25 CFR 1000.276 - Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA? 1000.276 Section 1000.276 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS...-governance AFA if FTCA is not referenced in the AFA? Yes, FTCA applies even if the AFA does not mention it....

  8. 25 CFR 1000.276 - Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Does FTCA apply to a self-governance AFA if FTCA is not referenced in the AFA? 1000.276 Section 1000.276 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS...-governance AFA if FTCA is not referenced in the AFA? Yes, FTCA applies even if the AFA does not mention it....

  9. Good Crab, Bad Crab

    EPA Science Inventory

    Are crabs friends or foes of marsh grass, benefit or detriment to the salt marsh system? We examined Uca pugilator (sand fiddler) and Sesarma reticulatum (purple marsh crab) with Spartina patens (salt marsh hay) at two elevations (10 cm below MHW and 10 cm above MHW) in mesocosms...

  10. 25 CFR 1000.408 - Can a Tribe/Consortium use Federal supply sources in the performance of an AFA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Can a Tribe/Consortium use Federal supply sources in the performance of an AFA? 1000.408 Section 1000.408 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION...

  11. Distribution and degree of heterogeneity of the afimbrial-adhesin-encoding operon (afa) among uropathogenic Escherichia coli isolates.

    PubMed

    Labigne-Roussel, A; Falkow, S

    1988-03-01

    The afimbrial adhesin (AFA-I) from a pyelonephritic Escherichia coli isolate (KS52) is a mannose-resistant, P-independent, X-binding adhesin, expressed by the afa-1 operon. It is distinct from the E. coli X-binding adhesins with M and S specificity. A total of 138 E. coli isolates belonging to various serotypes, mostly from urinary tract infections, were screened for the presence of DNA sequences related to the afa operon and for the expression of an X-adhesin able to mediate mannose-resistant hemagglutination (MRHA) and adhesion to uroepithelial cells. Fifteen strains were shown to harbor DNA sequences related to the AFA-I-encoding operon, and 13 of them expressed an X-adhesin. Using as probes different DNA segments of the AFA-I-encoding operon in Southern experiments, we demonstrated that only three of these clinical isolates contained genetic determinants closely related to those identified in the original afa prototype strain (KS52): presence of the afaA, afaB, afaC, afaD, and afaE genes associated with the expression of a 16,000-dalton hemagglutinin-adhesin which strongly cross-reacted with AFA-I-specific antibodies. The other E. coli isolates harbored DNA sequences homologous to the afaA, afaB, afaC, and afaD genes, but lacked the sequence corresponding to the adhesin-producing gene afaE; Western blots allowed the detection of polypeptides (15,000, 15,500, or 16,000 daltons) in these strains which cross-reacted with variable intensity with antibodies raised against the denatured AFA-I protein, but did not cross-react with native AFA-I-specific antibodies. Following DNA cloning experiments from chromosomal DNA of two of those strains (A22 and A30), we demonstrated that although the AFA-related operon in A22 and A30 strains lacked the AFA-I adhesin-encoding gene, they synthesized a functional X-adhesin. Thus, strains A22 and A30 encode adhesins designated AFA-II and AFA-III, which were cloned on recombinant plasmids pILL72 and pILL61, respectively. Southern

  12. 25 CFR 1000.278 - Does this coverage extend to subcontractors of self-governance AFAs?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Does this coverage extend to subcontractors of self-governance AFAs? 1000.278 Section 1000.278 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS... subcontractors of self-governance AFAs? No, subcontractors or subgrantees providing services to a Pub. L....

  13. 25 CFR 1000.278 - Does this coverage extend to subcontractors of self-governance AFAs?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Does this coverage extend to subcontractors of self-governance AFAs? 1000.278 Section 1000.278 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS... subcontractors of self-governance AFAs? No, subcontractors or subgrantees providing services to a Pub. L....

  14. 25 CFR 1000.278 - Does this coverage extend to subcontractors of self-governance AFAs?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Does this coverage extend to subcontractors of self-governance AFAs? 1000.278 Section 1000.278 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS... subcontractors of self-governance AFAs? No, subcontractors or subgrantees providing services to a Pub. L....

  15. 25 CFR 1000.278 - Does this coverage extend to subcontractors of self-governance AFAs?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Does this coverage extend to subcontractors of self-governance AFAs? 1000.278 Section 1000.278 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS... subcontractors of self-governance AFAs? No, subcontractors or subgrantees providing services to a Pub. L....

  16. 25 CFR 1000.278 - Does this coverage extend to subcontractors of self-governance AFAs?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Does this coverage extend to subcontractors of self-governance AFAs? 1000.278 Section 1000.278 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS... subcontractors of self-governance AFAs? No, subcontractors or subgrantees providing services to a Pub. L....

  17. Evidence and Ethics in Individual Events: An Examination of an AFA-NIET Final Round.

    ERIC Educational Resources Information Center

    Cronn-Mills, Daniel; Schnoor, Larry G.

    A study investigated the use of source citations and evidence in the final round of Informative Speaking at the 1998 American Forensic Association-National Individual Events Tournament (AFA-NIET). The "AFA Code of Forensics Program and Forensics Tournament Standards for College and Universities" was the framework for the analysis. Videotapes of…

  18. Horseshoe crabs.

    PubMed

    Botton, Mark L

    2002-10-01

    Horseshoe crabs are one of evolution's success stories. These living fossils have contributed immensely to biomedical research, and their eggs are a critical link in the migration cycle of New World waders (shorebirds) Can they endure threats posed by a growing commercial fishery and the loss of essential spawning habitats?

  19. Nucleotide sequence of the afimbrial-adhesin-encoding afa-3 gene cluster and its translocation via flanking IS1 insertion sequences.

    PubMed Central

    Garcia, M I; Labigne, A; Le Bouguenec, C

    1994-01-01

    The afa gene clusters encode afimbrial adhesins (AFAs) that are expressed by uropathogenic and diarrhea-associated Escherichia coli strains. The plasmid-borne afa-3 gene cluster is responsible for the biosynthesis of the AFA-III adhesin that belongs to the Dr family of hemagglutinins. Reported in this work is the nucleotide sequence of the 9.2-kb insert of the recombinant plasmid pILL61, which contains the afa-3 gene cluster cloned from a cystitis-associated E. coli strain (A30). The afa-3 gene cluster was shown to contain six open reading frames, designated afaA to afaF. It was organized in two divergent transcriptional units. Five of the six Afa products showed marked homologies with proteins encoded by previously described adhesion systems that allowed us to attribute to each of them a putative function in the biogenesis of the AFA-III adhesin. AfaE was identified as the structural adhesin product, whereas AfaB and AfaC were recognized as periplasmic chaperone and outer membrane anchor proteins, respectively. The AfaA and AfaF products were shown to be homologous to the PapI-PapB transcriptional regulatory proteins. No function could be attributed to the AfaD product, the gene of which was previously shown to be dispensable for the synthesis of a functional adhesin. Upstream of the afa-3 gene cluster, a 1.2-kb region was found to be 96% identical to the RepFIB sequence of one of the enterotoxigenic E. coli plasmids (P307), suggesting a common ancestor plasmid. This region contains an integrase-like gene (int). Sequence analysis revealed the presence of an IS1 element between the int gene and the afa-3 gene cluster. Two other IS1 elements were detected and located in the vicinity of the afa-3 gene cluster by hybridization experiments. The afa-3 gene cluster was therefore found to be flanked by two IS1 elements in direct orientation and two in opposite orientations. The afa-3 gene cluster, flanked by two directly oriented IS1 elements, was shown to translocate

  20. 25 CFR 1000.335 - How will retrocession affect the Tribe's/Consortium's existing and future AFAs?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... include retroceded programs in future AFAs or through a self-determination contract. ... existing and future AFAs? 1000.335 Section 1000.335 Indians OFFICE OF THE ASSISTANT SECRETARY, INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT...

  1. 25 CFR 1000.246 - Must an AFA that contains a construction project or activity incorporate provisions of Federal...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Must an AFA that contains a construction project or activity incorporate provisions of Federal construction standards? 1000.246 Section 1000.246 Indians OFFICE... Construction § 1000.246 Must an AFA that contains a construction project or activity incorporate provisions...

  2. 25 CFR 1000.246 - Must an AFA that contains a construction project or activity incorporate provisions of Federal...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Must an AFA that contains a construction project or activity incorporate provisions of Federal construction standards? 1000.246 Section 1000.246 Indians OFFICE... Construction § 1000.246 Must an AFA that contains a construction project or activity incorporate provisions...

  3. 25 CFR 1000.246 - Must an AFA that contains a construction project or activity incorporate provisions of Federal...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Must an AFA that contains a construction project or activity incorporate provisions of Federal construction standards? 1000.246 Section 1000.246 Indians OFFICE... Construction § 1000.246 Must an AFA that contains a construction project or activity incorporate provisions...

  4. 25 CFR 1000.246 - Must an AFA that contains a construction project or activity incorporate provisions of Federal...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Must an AFA that contains a construction project or activity incorporate provisions of Federal construction standards? 1000.246 Section 1000.246 Indians OFFICE... Construction § 1000.246 Must an AFA that contains a construction project or activity incorporate provisions...

  5. 25 CFR 1000.246 - Must an AFA that contains a construction project or activity incorporate provisions of Federal...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Must an AFA that contains a construction project or activity incorporate provisions of Federal construction standards? 1000.246 Section 1000.246 Indians OFFICE... Construction § 1000.246 Must an AFA that contains a construction project or activity incorporate provisions...

  6. 25 CFR 1000.275 - Is it necessary for a self-governance AFA to include any clauses about FTCA coverage?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Is it necessary for a self-governance AFA to include any... for a self-governance AFA to include any clauses about FTCA coverage? No, clauses about FTCA coverage are optional. At the request of Tribes/Consortia, self-governance AFA's shall include the...

  7. 25 CFR 1000.275 - Is it necessary for a self-governance AFA to include any clauses about FTCA coverage?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Is it necessary for a self-governance AFA to include any... for a self-governance AFA to include any clauses about FTCA coverage? No, clauses about FTCA coverage are optional. At the request of Tribes/Consortia, self-governance AFA's shall include the...

  8. 25 CFR 1000.275 - Is it necessary for a self-governance AFA to include any clauses about FTCA coverage?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Is it necessary for a self-governance AFA to include any... for a self-governance AFA to include any clauses about FTCA coverage? No, clauses about FTCA coverage are optional. At the request of Tribes/Consortia, self-governance AFA's shall include the...

  9. 25 CFR 1000.275 - Is it necessary for a self-governance AFA to include any clauses about FTCA coverage?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Is it necessary for a self-governance AFA to include any... for a self-governance AFA to include any clauses about FTCA coverage? No, clauses about FTCA coverage are optional. At the request of Tribes/Consortia, self-governance AFA's shall include the...

  10. 25 CFR 1000.275 - Is it necessary for a self-governance AFA to include any clauses about FTCA coverage?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Is it necessary for a self-governance AFA to include any... for a self-governance AFA to include any clauses about FTCA coverage? No, clauses about FTCA coverage are optional. At the request of Tribes/Consortia, self-governance AFA's shall include the...

  11. Land crabs as key drivers in tropical coastal forest recruitment

    USGS Publications Warehouse

    Lindquist, E.S.; Krauss, K.W.; Green, P.T.; O'Dowd, D. J.; Sherman, P.M.; Smith, T. J.

    2009-01-01

    Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystems-mangroves, island maritime forests, and mainland coastal terrestrial forests-where land crabs directly influence forest composition by limiting tree establishment and recruitment. Land crabs differentially prey on seeds, propagules and seedlings along nutrient, chemical and physical environmental gradients. In all of these ecosystems, but especially mangroves, abiotic gradients are well studied, strong and influence plant species distributions. However, we suggest that crab predation has primacy over many of these environmental factors by acting as the first limiting factor of tropical tree recruitment to drive the potential structural and compositional organisation of coastal forests. We show that the influence of crabs varies relative to tidal gradient, shoreline distance, canopy position, time, season, tree species and fruiting periodicity. Crabs also facilitate forest growth and development through such activities as excavation of burrows, creation of soil mounds, aeration of soils, removal of leaf litter into burrows and creation of carbon-rich soil microhabitats. For all three systems, land crabs influence the distribution, density and size-class structure of tree populations. Indeed, crabs are among the major drivers of tree recruitment in tropical coastal forest ecosystems, and their conservation should be included in management plans of these forests. ?? 2009 Cambridge Philosophical Society.

  12. Land crabs as key drivers in tropical coastal forest recruitment.

    PubMed

    Lindquist, Erin Stewart; Krauss, Ken W; Green, Peter T; O'Dowd, Dennis J; Sherman, Peter M; Smith, Thomas J

    2009-05-01

    Plant populations are regulated by a diverse assortment of abiotic and biotic factors that influence seed dispersal and viability, and seedling establishment and growth at the microsite. Rarely does one animal guild exert as significant an influence on different plant assemblages as land crabs. We review three tropical coastal ecosystems-mangroves, island maritime forests, and mainland coastal terrestrial forests-where land crabs directly influence forest composition by limiting tree establishment and recruitment. Land crabs differentially prey on seeds, propagules and seedlings along nutrient, chemical and physical environmental gradients. In all of these ecosystems, but especially mangroves, abiotic gradients are well studied, strong and influence plant species distributions. However, we suggest that crab predation has primacy over many of these environmental factors by acting as the first limiting factor of tropical tree recruitment to drive the potential structural and compositional organisation of coastal forests. We show that the influence of crabs varies relative to tidal gradient, shoreline distance, canopy position, time, season, tree species and fruiting periodicity. Crabs also facilitate forest growth and development through such activities as excavation of burrows, creation of soil mounds, aeration of soils, removal of leaf litter into burrows and creation of carbon-rich soil microhabitats. For all three systems, land crabs influence the distribution, density and size-class structure of tree populations. Indeed, crabs are among the major drivers of tree recruitment in tropical coastal forest ecosystems, and their conservation should be included in management plans of these forests.

  13. CHANGES IN THE CRAB PULSAR

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Scientists are learning more about how pulsars work by studying a series of Hubble Space Telescope images of the heart of the Crab Nebula. The images, taken over a period of several months, show that the Crab is a far more dynamic object than previously understood. At the center of the nebula lies the Crab Pulsar. The pulsar is a tiny object by astronomical standards -- only about six miles across -- but has a mass greater than that of the Sun and rotates at a rate of 30 times a second. As the pulsar spins its intense magnetic field whips around, acting like a sling shot, accelerating subatomic particles and sending them hurtling them into space at close to the speed of light. The tiny pulsar and its wind are the powerhouse for the entire Crab Nebula, which is 10 light-years across -- a feat comparable to an object the size of a hydrogen atom illuminating a volume of space a kilometer across. The three pictures shown here, taken from the series of Hubble images, show dramatic changes in the appearance of the central regions of the nebula. These include wisp-like structures that move outward away from the pulsar at half the speed of light, as well as a mysterious 'halo' which remains stationary, but grows brighter then fainter over time. Also seen are the effects of two polar jets that move out along the rotation axis of the pulsar. The most dynamic feature seen -- a small knot that 'dances around' so much that astronomers have been calling it a 'sprite' -- is actually a shock front (where fast-moving material runs into slower-moving material)in one of these polar jets. The telescope captured the images with the Wide Field and Planetary Camera 2 using a filter that passes light of wavelength around 550 nanometers, near the middle of the visible part of the spectrum. The Crab Nebula is located 7,000 light-years away in the constellation Taurus. Credit: Jeff Hester and Paul Scowen (Arizona State University), and NASA

  14. 78 FR 15705 - Proposed Information Collection; Comment Request; American Fisheries Act (AFA): Permits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... program, the Chinook Salmon Prohibited Species Catch Program (Chinook PSC Program). The Chinook PSC Program was established to promote reduction of Chinook salmon PSC in the Bering Sea pollock fishery to... bycatch at all levels of Chinook salmon abundance. NMFS issues transferable Chinook salmon PSC...

  15. CLIC Crab Cavity Design Optimisation for Maximum Luminosity

    SciTech Connect

    Dexter, A.C.; Burt, G.; Ambattu, P.K.; Dolgashev, V.; Jones, R.; /Manchester U.

    2012-04-25

    The bunch size and crossing angle planned for CERN's compact linear collider CLIC dictate that crab cavities on opposing linacs will be needed to rotate bunches of particles into alignment at the interaction point if the desired luminosity is to be achieved. Wakefield effects, RF phase errors between crab cavities on opposing linacs and unpredictable beam loading can each act to reduce luminosity below that anticipated for bunches colliding in perfect alignment. Unlike acceleration cavities, which are normally optimised for gradient, crab cavities must be optimised primarily for luminosity. Accepting the crab cavity technology choice of a 12 GHz, normal conducting, travelling wave structure as explained in the text, this paper develops an analytical approach to optimise cell number and iris diameter.

  16. The Crab Nebula's progenitor

    NASA Technical Reports Server (NTRS)

    Nomoto, K.; Sugimoto, D.; Sparks, W. M.; Fesen, R. A.; Gull, T. R.; Miyaji, S.

    1982-01-01

    The initial mass of the Crab Nebula's progenitor star is estimated by comparing the observed nebular chemical abundances with detailed evolutionary calculations for 2.4- and 2.6-solar-mass helium cores of stars with masses of 8 to 10 solar masses. The results indicate that the mass of the Crab's progenitor was between the upper limit of about 8 solar masses for carbon deflagration and the lower limit of about 9.5 solar masses set by the dredge-up of the helium layer before the development of the helium-burning convective region. A scenario is outlined for the evolution of the progenitor star. It is suggested that the Crab Nebula was probably the product of an electron-capture supernova.

  17. 25 CFR 1000.123 - Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to such terms as the parties may negotiate? 1000.123 Section 1000... there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to...

  18. 25 CFR 1000.123 - Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to such terms as the parties may negotiate? 1000.123 Section 1000... there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to...

  19. 25 CFR 1000.123 - Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to such terms as the parties may negotiate? 1000.123 Section 1000... there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to...

  20. 25 CFR 1000.123 - Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to such terms as the parties may negotiate? 1000.123 Section 1000... there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to...

  1. 25 CFR 1000.123 - Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Are there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to such terms as the parties may negotiate? 1000.123 Section 1000... there non-BIA programs for which the Secretary must negotiate for inclusion in an AFA subject to...

  2. The Crab Halo

    NASA Astrophysics Data System (ADS)

    Lundqvist, Peter

    2011-10-01

    The Crab Nebula, along with its central pulsar and its explosive originin SN 1054, plays a crucial role in our understanding of the linkbetween supernovae and pulsar formation and activity.Yet, there are fundamental uncertainties in the nature of the event thathave not been settled in more than two decades of investigation.The observed mass in the nebula and pulsar is nearly half of theexpected initial stellar mass and the observed energy {much of whichmay come from the central pulsar} is only a fewpercent of the typical supernova energy.An attractive solution to this ``missing mass'' problem is that this massis in a high velocity envelope around the observed Crab Nebula.The envelope would have most of the energy of the explosion {roughly 10^{51} ergs}, bringing the energy up to that typical of a Type II supernova. The fact that the Crab filaments have a measured acceleration and show no deceleration at the outer edge is consistent with this hypothesis. The lack of an interaction region created by the fast shell can be attributed to a very low density around the supernova. We propose to search for the fast shell by taking a COS spectrum of the Crab pulsar in the region of the C IV 1550 line. We have carried out time-dependent ionization calculations that show that this line should produce a detectable broad, blueshifted absorption if the shell is present.

  3. Development and Exploratory Scale-Up of Alumina-Forming Austenitic (AFA) Stainless Steels

    SciTech Connect

    Brady, Michael P; Magee, John H; Yamamoto, Yukinori; Maziasz, Philip J; Santella, Michael L; Pint, Bruce A; Bei, Hongbin

    2009-01-01

    This paper presents the results of the continued development of creep-resistant, alumina-forming austenitic (AFA) stainless steel alloys, which exhibit a unique combination of excellent oxidation resistance via protective alumina (Al2O3) scale formation and high-temperature creep strength through the formation of stable nano-scale MC carbides and intermetallic precipitates. Efforts in fiscal year 2009 focused on the characterization and understanding of long-term oxidation resistance and tensile properties as a function of alloy composition and microstructure. Computational thermodynamic calculations of the austenitic matrix phase composition and the volume fraction of MC, B2-NiAl, and Fe2(Mo,Nb) base Laves phase precipitates were used to interpret oxidation behavior. Of particular interest was the enrichment of Cr in the austenitic matrix phase by additions of Nb, which aided the establishment and maintenance of alumina. Higher levels of Nb additions also increased the volume fraction of B2-NiAl precipitates, which served as an Al reservoir during long-term oxidation. Ageing studies of AFA alloys were conducted at 750C for times up to 2000 h. Ageing resulted in near doubling of yield strength at room temperature after only 50 h at 750C, with little further increase in yield strength out to 2000 h of ageing. Elongation was reduced on ageing; however, levels of 15-25% were retained at room temperature after 2000 h of total ageing.

  4. 25 CFR 1000.240 - What construction programs included in an AFA are subject to this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... procurement except that all project design and actual construction activities are subject to all the... AFA are subject to this subpart. This includes design, construction, repair, improvement, expansion... Tribal, facilities and projects. (b) The following programs and activities are not construction...

  5. 25 CFR 1000.240 - What construction programs included in an AFA are subject to this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... procurement except that all project design and actual construction activities are subject to all the... AFA are subject to this subpart. This includes design, construction, repair, improvement, expansion... Tribal, facilities and projects. (b) The following programs and activities are not construction...

  6. 25 CFR 1000.240 - What construction programs included in an AFA are subject to this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... procurement except that all project design and actual construction activities are subject to all the... AFA are subject to this subpart. This includes design, construction, repair, improvement, expansion... Tribal, facilities and projects. (b) The following programs and activities are not construction...

  7. 25 CFR 1000.240 - What construction programs included in an AFA are subject to this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... procurement except that all project design and actual construction activities are subject to all the... AFA are subject to this subpart. This includes design, construction, repair, improvement, expansion... Tribal, facilities and projects. (b) The following programs and activities are not construction...

  8. 25 CFR 1000.240 - What construction programs included in an AFA are subject to this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... procurement except that all project design and actual construction activities are subject to all the... AFA are subject to this subpart. This includes design, construction, repair, improvement, expansion... Tribal, facilities and projects. (b) The following programs and activities are not construction...

  9. Crab allergen exposures aboard five crab-processing vessels.

    PubMed

    Beaudet, Nancy; Brodkin, C Andrew; Stover, Bert; Daroowalla, Feroza; Flack, Joy; Doherty, Dan

    2002-01-01

    Aerosolized crab allergens are suspected etiologic agents for asthma among crab-processing workers. The objectives of this study were to characterize crab allergen concentrations and respiratory symptom prevalence among processing workers aboard crab-processing vessels. A cross-sectional survey of five crab-processing vessels was conducted near Dutch Harbor, Alaska. Crab allergen concentrations were quantified during specific work activities with 25 personal air samples collected on polytetrafluoroethylene filters and analyzed by a competitive IgE immunoassay technique. Two standardized respiratory questionnaires were used to assess respiratory symptoms suggestive of bronchitis or asthma in 82 workers. Aerosolized crab allergen concentrations ranged from 79 ng/m3 to 21,093 ng/m3 (mean = 2797 ng/m3, SD = 4576 ng/m3). The highest concentrations were measured at butchering/degilling work stations, which were combined on the smallest vessel. A significant percentage of workers reported development of respiratory symptoms during the crab-processing season. Cough developed in 28% of workers, phlegm in 11% of workers, and wheeze and other asthma-like symptoms developed in 4% of workers. Despite variations in crab allergen levels, respiratory symptom prevalence was similar across all job categories. Substantial concentrations of crab allergen exposure were measured, as well as the potential for wide variability in exposure during crab processing aboard vessels. The high prevalence of reported respiratory symptoms across all job categories suggests potential adverse respiratory effects that should be further characterized by prospective studies using pulmonary function and serology testing, and rigorous exposure characterization.

  10. 50 CFR Table 5 to Part 680 - Crab Size Codes

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Size Codes 5 Table 5 to Part 680..., Table 5 Table 5 to Part 680—Crab Size Codes Size code Description 1 Standard or large sized crab or crab sections. 2 Smaller size crab or crab sections, e.g., snow crab less than 4 inches....

  11. 50 CFR Table 5 to Part 680 - Crab Size Codes

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Size Codes 5 Table 5 to Part 680..., Table 5 Table 5 to Part 680—Crab Size Codes Size code Description 1 Standard or large sized crab or crab sections. 2 Smaller size crab or crab sections, e.g., snow crab less than 4 inches....

  12. 50 CFR Table 5 to Part 680 - Crab Size Codes

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab Size Codes 5 Table 5 to Part 680..., Table 5 Table 5 to Part 680—Crab Size Codes Size code Description 1 Standard or large sized crab or crab sections. 2 Smaller size crab or crab sections, e.g., snow crab less than 4 inches....

  13. 77 FR 19144 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod for American Fisheries Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-30

    ... (77 FR 10669, February 23, 2012). In accordance with Sec. 679.20(d)(1)(i) and (d)(1)(ii)(B), the... Economic Zone Off Alaska; Pacific Cod for American Fisheries Act Catcher/Processors Using Trawl Gear in the...: NMFS is prohibiting directed fishing for Pacific cod by American Fisheries Act (AFA) trawl...

  14. 75 FR 17315 - Fisheries of the Exclusive Economic Zone Off Alaska; Pacific Cod for American Fisheries Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ... by the final 2010 and 2011 harvest specifications for groundfish in the BSAI (75 FR 11788, March 12... Economic Zone Off Alaska; Pacific Cod for American Fisheries Act Catcher Processors Using Trawl Gear in the...: NMFS is prohibiting directed fishing for Pacific cod by American Fisheries Act (AFA) trawl...

  15. CRAB Cavity in CERN SPS

    SciTech Connect

    Kim, H.J.; Sen, T.; /Fermilab

    2010-05-01

    Beam collisions with a crossing angle at the interaction point are often necessary in colliders to reduce the effects of parasitic collisions which induce emittance growth and decrease beam lifetime. The crossing angle reduces the geometrical overlap of the beams and hence the luminosity. Crab cavity offer a promising way to compensate the crossing angle and to realize effective head-on collisions. Moreover, the crab crossing mitigates the synchro-betatron resonances due to the crossing angle. A crab cavity experiment in SPS is proposed as a proof of principle before deciding on a full crab-cavity implementation in the LHC. In this paper, we investigate the effects of a single crab cavity on beam dynamics in the SPS and life time.

  16. Crab Cavities for Linear Colliders

    SciTech Connect

    Burt, G.; Ambattu, P.; Carter, R.; Dexter, A.; Tahir, I.; Beard, C.; Dykes, M.; Goudket, P.; Kalinin, A.; Ma, L.; McIntosh, P.; Shulte, D.; Jones, Roger M.; Bellantoni, L.; Chase, B.; Church, M.; Khabouline, T.; Latina, A.; Adolphsen, C.; Li, Z.; Seryi, Andrei; /SLAC

    2011-11-08

    Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

  17. 25 CFR 1000.33 - What amount of funding is to be removed from the Consortium's AFA for the withdrawing Tribe?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the funds were included in the Consortium's AFA. (a) If there is not a clear identifiable methodology... amount of funds passed directly to the Tribe, or already spent or obligated by the Consortium on...

  18. 25 CFR 1000.33 - What amount of funding is to be removed from the Consortium's AFA for the withdrawing Tribe?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the funds were included in the Consortium's AFA. (a) If there is not a clear identifiable methodology... amount of funds passed directly to the Tribe, or already spent or obligated by the Consortium on...

  19. 50 CFR Table 2 to Part 680 - Crab Species Code

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Lopholithodes mandtii. 910 Dungeness Cancer magister. 921 Red king crab Paralithodes camtshaticus. 922 Blue king crab Paralithodes platypus. 923 Golden (brown) king crab Lithodes aequispinus. 924 Scarlet king...

  20. 50 CFR Table 2 to Part 680 - Crab Species Code

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Lopholithodes mandtii. 910 Dungeness Cancer magister. 921 Red king crab Paralithodes camtshaticus. 922 Blue king crab Paralithodes platypus. 923 Golden (brown) king crab Lithodes aequispinus. 924 Scarlet king...

  1. 50 CFR Table 2 to Part 680 - Crab Species Code

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Lopholithodes mandtii. 910 Dungeness Cancer magister. 921 Red king crab Paralithodes camtshaticus. 922 Blue king crab Paralithodes platypus. 923 Golden (brown) king crab Lithodes aequispinus. 924 Scarlet king...

  2. CRADA No. NFE-10-02715 Assessment of AFA Stainless Steels for Tube Products in Chemical Processing and Energy Production Applications

    SciTech Connect

    Brady, Michael P; Yamamoto, Yukinori; Epler, Mario; Magee, John H

    2011-09-01

    Oak Ridge National Laboratory (ORNL) and Carpenter Technology Corporation (Carpenter) participated in an in-kind cost share cooperative research and development agreement (CRADA) effort under the auspices of the Energy Efficiency and Renewable Energy (EERE) Technology Maturation Program to assess material properties of several potential AFA family grades and explore the feasibility of producing alumina-forming austenitic (AFA) stainless steels in tubular form needed for many power generation and chemical process applications. Carpenter's Research Laboratory successfully vacuum melted 30 lb heats of seven candidate AFA alloy compositions representing a wide range of alloy content and intended application temperatures. These compositions were evaluated by ORNL and Carpenter R&D for microstructure, tensile properties, creep properties, and oxidation resistance. In parallel, additional work was directed toward an initial tube manufacture demonstration of a baseline AFA alloy. Carpenter successfully manufactured a 10,000 lb production heat and delivered appropriate billets to a partner for extrusion evaluation. Tube product was successfully manufactured from the baseline AFA alloy, indicating good potential for commercially produced AFA tubular form material.

  3. Anthropological facial approximation in three dimensions (AFA3D): computer-assisted estimation of the facial morphology using geometric morphometrics.

    PubMed

    Guyomarc'h, Pierre; Dutailly, Bruno; Charton, Jérôme; Santos, Frédéric; Desbarats, Pascal; Coqueugniot, Hélène

    2014-11-01

    This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re-sampling on a subsample demonstrated an average accuracy of c. 4 mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.

  4. SPERMIOGENESIS IN CANCER CRABS

    PubMed Central

    Langreth, Susan G.

    1969-01-01

    Spermiogenesis in Cancer crabs was studied by light and electron microscopy. The sperm are aflagellate, and when mature consist primarily of a spherical acrosome surrounded by the nucleus with its short radiating arms. The acrosome forms by a coalescence of periodic acid-Schiff-positive (PAS-positive) vesicles. During spermiogenesis one edge of the acrosomal vesicle invaginates to form a PAS-negative central core. The inner region of the acrosome bounding the core contains basic proteins which are not complexed to nucleic acid. The formation of an elaborate lattice-like complex of fused membranes, principally from membranes of the endoplasmic reticulum, is described. These membranes are later taken into the nucleus and subsequently degenerate. In late spermatids, when most of the cytoplasm is sloughed, the nuclear envelope and the cell membrane apparently fuse to become the limiting boundary over most of the sperm cell. In the mature sperm the chromatin of the nucleus and arms, which is Feulgen-positive, contains no detectable protein. The chromatin filaments appear clumped, branched, and anastomosed; morphologically, they resemble the DNA of bacterial nuclei. Mitochondria are absent or degenerate in mature sperm of Cancer crabs, but the centrioles persist in the nucleoplasm at the base of the acrosome. PMID:4187136

  5. Novel Crab Cavity RF Design

    SciTech Connect

    Dudas, A.; Neubauer, M. L.; Sah, R.; Rimmer, B.; Wang, H.

    2011-03-01

    A 20-50 MV integrated transverse voltage is required for the Electron-Ion Collider. The most promising of the crab cavity designs that have been proposed in the last five years are the TEM type crab cavities because of the higher transverse impedance. The TEM design approach is extended here to a hybrid crab cavity that includes the input power coupler as an integral part of the design. A prototype was built with Phase I monies and tested at JLAB. The results reported on, and a system for achieving 20-50 MV is proposed.

  6. Gas Generation and Hold-Up in Hanford Waste Treatment Plant Process Streams Containing Anti-Foam Agent (AFA)

    SciTech Connect

    Arm, Stuart T.; Poloski, Adam P.; Stewart, Charles W.; Meyer, Perry A.; Kurath, Dean E.

    2007-06-29

    The Waste Treatment and Immobilization Plant (WTP) is being designed and built to pretreat and vitrify defense wastes stored at the DOE Hanford Site near Richland, Washington. Some of the WTP process streams are slurries that exhibit non-Newtonian rheological behavior. Such streams can accumulate hazardous quantities of thermally and radiolytically generated flammable gases. Experiments were performed in a bubble column to measure gas hold-up under various conditions to better understand flammable gas behavior in WTP processes. The two non-Newtonian slurries tested were kaolin-bentonite clay and a chemical surrogate of pretreated high-level waste (HLW) from Hanford Tank AZ-101. The addition of solutes, whether a salt or anti-foaming agent (AFA) decrease the bubble coalescence rate leading to smaller bubbles, lower bubble rise velocity and higher gas holdup. Gas holdup decreased with increasing yield stress and consistency. The impact of AFA on gas holdup in kaolin-bentonite clay was less than in simulated HLW, presumably because the AFA adsorbed onto the clay particles, rendering it unavailable to retard coalescence.

  7. 75 FR 31421 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Application for Exempted...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-03

    ... the Federal Register on June 2, 2008 (73 FR 31434), and thus are not repeated here. Data collected... Management Act Provisions; Application for Exempted Fishing Permit; Horseshoe Crabs AGENCY: National Marine... harvest of up to 10,000 horseshoe crabs from the Carl N. Shuster Jr. Horseshoe Crab Reserve for...

  8. What regulates crab predation on mangrove propagules?

    NASA Astrophysics Data System (ADS)

    Van Nedervelde, Fleur; Cannicci, Stefano; Koedam, Nico; Bosire, Jared; Dahdouh-Guebas, Farid

    2015-02-01

    Crabs play a major role in some ecosystems. To increase our knowledge about the factors that influence crab predation on propagules in mangrove forests, we performed experiments in Gazi Bay, Kenya in July 2009. We tested whether: (1) crab density influences propagule predation rate; (2) crab size influences food competition and predation rate; (3) crabs depredate at different rates according to propagule and canopy cover species; (4) vegetation density is correlated with crab density; (5) food preferences of herbivorous crabs are determined by size, shape and nutritional value. We found that (1) propagule predation rate was positively correlated to crab density. (2) Crab competitive abilities were unrelated to their size. (3) Avicennia marina propagules were consumed more quickly than Ceriops tagal except under C. tagal canopies. (4) Crab density was negatively correlated with the density of A. marina trees and pneumatophores. (5) Crabs prefer small items with a lower C:N ratio. Vegetation density influences crab density, and crab density affects propagule availability and hence vegetation recruitment rate. Consequently, the mutual relationships between vegetation and crab populations could be important for forest restoration success and management.

  9. The Great Crab Nebula Superflare

    NASA Video Gallery

    There are strange goings-on in the Crab Nebula. On April 12, 2011, NASA's Fermi Gamma-ray Space Telescope detected the most powerful in a series of gamma-ray flares occurring somewhere within the s...

  10. Antarctic Crabs: Invasion or Endurance?

    PubMed Central

    Griffiths, Huw J.; Whittle, Rowan J.; Roberts, Stephen J.; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the “discovery” of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This “invasion hypothesis” suggests that decapod crabs were driven out of Antarctica 40–15 million years ago and are only now returning as “warm” enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60°S. All are restricted to waters warmer than 0°C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day “crab invasion”. We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the

  11. Antarctic crabs: invasion or endurance?

    PubMed

    Griffiths, Huw J; Whittle, Rowan J; Roberts, Stephen J; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis

  12. Antarctic crabs: invasion or endurance?

    PubMed

    Griffiths, Huw J; Whittle, Rowan J; Roberts, Stephen J; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis".

  13. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  14. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  15. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  16. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  17. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  18. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  19. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  20. 40 CFR 408.60 - Applicability; description of the non-remote Alaskan whole crab and crab section processing...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan whole crab and crab section processing subcategory. 408.60 Section 408.60 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.60 Applicability; description of the non-remote Alaskan whole crab and crab...

  1. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  2. 40 CFR 408.70 - Applicability; description of the remote Alaskan whole crab and crab section processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan whole crab and crab section processing subcategory. 408.70 Section 408.70 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Remote Alaskan Whole Crab and Crab Section Processing Subcategory § 408.70 Applicability; description of the remote Alaskan whole crab and crab section...

  3. 50 CFR Table 7 to Part 680 - Initial Issuance of Crab QS by Crab QS Fishery

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... fisheries. 4 years 5. Pribilof red king and blue king crab (PIK) 4 years of the 5-year period beginning on... requirement. 4 years 6. St. Matthew blue king crab (SMB) 4 years of the 5-year period beginning on:(1... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Initial Issuance of Crab QS by Crab...

  4. Distortion of Crabbed Bunch Due to Electron Cloud and Global Crabbing

    SciTech Connect

    Wang, L.; Raubenheimer, T.O.; Cai, Y.; /SLAC

    2008-08-01

    Crab cavities may be used improve the luminosity in colliding beam colliders with crab crossing. In a global crab crossing correction, only one crab cavity is installed in each ring and the crab cavities generate a horizontally titled bunch oscillating around the ring. The electron cloud in positively charged rings may distort the crabbed bunch and cause the luminosity drop. This paper briefly estimates the distortion of positron bunch due to the electron cloud with global crab and estimates the effect in the KEKB and possible LHC upgrades.

  5. 78 FR 25426 - Fisheries of the Exclusive Economic Zone Off Alaska; American Fisheries Act, Amendment 80 Program...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-01

    ...NMFS announces two workshops to solicit input from participants in the pollock fishery in the Bering Sea authorized under the American Fisheries Act (AFA), the Aleutian Islands pollock fishery, the Amendment 80 trawl fisheries in the Bering Sea and Aleutian Islands, and the Western Alaska Community Development Quota (CDQ) Program. The workshops will address (1) The applicability of cost......

  6. Are Crab nanoshots Schwinger sparks?

    SciTech Connect

    Stebbins, Albert; Yoo, Hojin

    2015-05-21

    The highest brightness temperature ever observed are from "nanoshots" from the Crab pulsar which we argue could be the signature of bursts of vacuum e± pair production. If so this would be the first time the astronomical Schwinger effect has been observed. These "Schwinger sparks" would be an intermittent but extremely powerful, ~103 L, 10 PeV e± accelerator in the heart of the Crab. These nanosecond duration sparks are generated in a volume less than 1 m3 and the existence of such sparks has implications for the small scale structure of the magnetic field of young pulsars such as the Crab. As a result, this mechanism may also play a role in producing other enigmatic bright short radio transients such as fast radio bursts.

  7. LHC crab-cavity aspects and strategy

    SciTech Connect

    Calaga, R.; Tomas, R.; Zimmermann, F.

    2010-05-23

    The 3rd LHC Crab Cavity workshop (LHC-CC09) took place at CERN in October 2009. It reviewed the current status and identified a clear strategy towards a future crab-cavity implementation. Following the success of crab cavities in KEK-B and the strong potential for luminosity gain and leveling, CERN will pursue crab crossing for the LHC upgrade. We present a summary and outcome of the variousworkshop sessions which have led to the LHC crab-cavity strategy, covering topics like layout, cavity design, integration, machine protection, and a potential validation test in the SPS.

  8. Twisted Crab fingers revisited

    NASA Astrophysics Data System (ADS)

    Carlqvist, Per

    2015-05-01

    Narrowband images of the Crab Nebula captured by the Hubble Space Telescope have earlier shown that the nebula does not only present a network of broad, bright filaments crossing the nebula but also numerous so-called fingers mostly pointing inwards. Using archival Hubble images we have in some detail studied the morphology of a great number of such fingers. This scrutiny has revealed that practically all the fingers are made up of filaments. Most of the larger fingers show overall shapes that are similar to either of the two letters V and Y. In many of these fingers it is also possible to see internal details. Interestingly, a number of the larger, Y-shaped fingers turn out to have a stem that consists of intertwined filaments. By contrast with this, the smaller fingers usually appear only as diffuse and sometimes incomplete pegs. In none of the smaller fingers is it possible to find any plain, internal structure. The observational results obtained are compared with the properties of a previously proposed model of the fingers. The model suggests that the fingers have evolved out of magnetized filaments. The evolution should lead to fingers with overall shapes that are similar to either a V or a Y, very much in agreement with the observations. In addition to this, the model prescribes that the stems of the Y-shaped fingers should be made up of intertwined filaments. From all these points of agreement we conclude that the properties of the fingers observed lend strong support to the model.

  9. 50 CFR Table 6 to Part 680 - Crab Grade Codes

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Grade Codes 6 Table 6 to Part 680..., Table 6 Table 6 to Part 680—Crab Grade Codes Grade/code Description 1 Standard or premium quality crab or crab sections. 2 Lower quality product, e.g., dirty shelled crab or a pack that is of...

  10. 50 CFR Table 6 to Part 680 - Crab Grade Codes

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab Grade Codes 6 Table 6 to Part 680..., Table 6 Table 6 to Part 680—Crab Grade Codes Grade/code Description 1 Standard or premium quality crab or crab sections. 2 Lower quality product, e.g., dirty shelled crab or a pack that is of...

  11. 50 CFR Table 6 to Part 680 - Crab Grade Codes

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Grade Codes 6 Table 6 to Part 680..., Table 6 Table 6 to Part 680—Crab Grade Codes Grade/code Description 1 Standard or premium quality crab or crab sections. 2 Lower quality product, e.g., dirty shelled crab or a pack that is of...

  12. 50 CFR 253.30 - Crab IFQ loans.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 CFR Part 680, Table 8; and (4) Who, at the time of initial application, meets all other applicable... Island (BSAI) King and Tanner Crab. (2) Crab FMP means the Fishery Management Plan for BSAI King and Tanner Crab. (3) Crab quota share means a BSAI King and Tanner Crab permit, the base amount of which...

  13. Detection of pap, sfa, afa, foc, and fim Adhesin-Encoding Operons in Uropathogenic Escherichia coli Isolates Collected From Patients With Urinary Tract Infection

    PubMed Central

    Rahdar, Masoud; Rashki, Ahmad; Miri, Hamid Reza; Rashki Ghalehnoo, Mehdi

    2015-01-01

    Background: Uropathogenic Escherichia coli (UPEC) with its virulence factors is the most prevalent cause of urinary tract infection (UTI). Objectives; This study aimed to determine the occurrence of fim, pap, sfa, and afa genes among 100 UPEC isolates collected from patients diagnosed with UTI. Materials and Methods A total of 100 UPEC isolates were obtained from urine samples of patients with UTI. The prevalence of 5 virulence genes encoding type 1 fimbriae (fimH), pili associated with pyelonephritis (pap), S and F1C fimbriae (sfa and foc) and afimbrial adhesins (afa) were determined through PCR method. We also investigated the phylogenetic background of all isolates. In addition, the distribution of adhesin-encoding operons between the phylogroups was assessed. Results: The prevalence of genes encoding for fimbrial adhesive systems was 95% for fim, 57% for pap, 16% for foc, and 81% for sfa. The operons encoding for afa afimbrial adhesins were identified in 12% of isolates. The various combinations of detected genes were designated as virulence patterns. The fim gene, which occurred in strains from all phylogenetic groups (A, B1, B2, and D) was evaluated and no significant differences were found among these groups. Conversely, significant differences were observed in relation to pap, afa, foc, and sfa operons. Conclusions: These results indicate that the PCR method is a powerful genotypic assay for the detection of adhesin-encoding operons. Thus, this assay can be recommended for clinical use to detect virulent urinary E. coli strains, as well as epidemiological studies. PMID:26464770

  14. 50 CFR Table 9 to Part 680 - Initial Issuance of Crab PQS by Crab QS Fishery

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Islands red and blue king crab (PIK) 3 years of the 3-year period beginning on: (1) September 15-26, 1996; (2) September 15-29, 1997; and (3) September 15-28, 1998. St. Matthew blue king crab (SMB) 3 years of... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Initial Issuance of Crab PQS by Crab...

  15. 50 CFR Table 9 to Part 680 - Initial Issuance of Crab PQS by Crab QS Fishery

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... fisheries for any... Bristol Bay red king crab (BBR) 3 years of the 3-year QS base period beginning on: (1... king crab (EAG) 4 years of the 4-year base period beginning on: (1) September 1, 1996 through December... Bristol Bay red king crab fishery during the qualifying years established for that fishery....

  16. 50 CFR 600.1103 - Bering Sea and Aleutian Islands (BSAI) Crab species program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT.../history vessel (see definition) harvested, according to the State of Alaska's records of the documented... office. Non-crab reduction permit means a fishing license, including all of its predecessor history,...

  17. Particle beam and crabbing and deflecting structure

    DOEpatents

    Delayen, Jean

    2011-02-08

    A new type of structure for the deflection and crabbing of particle bunches in particle accelerators comprising a number of parallel transverse electromagnetic (TEM)-resonant) lines operating in opposite phase from each other. Such a structure is significantly more compact than conventional crabbing cavities operating the transverse magnetic TM mode, thus allowing low frequency designs.

  18. HUBBLE CAPTURES DYNAMICS OF CRAB NEBULA (color)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A new sequence of Hubble Space Telescope images of the remnant of a tremendous stellar explosion is giving astronomers a remarkable look at the dynamic relationship between the tiny Crab Pulsar and the vast nebula that it powers. This colorful photo shows a ground-based image of the entire Crab Nebula, the remnant of a supernova explosion witnessed over 900 years ago. The nebula, which is 10 light-years across, is located 7,000 light-years away in the constellation Taurus. The green, yellow and red filaments concentrated toward the edges of the nebula are remnants of the star that were ejected into space by the explosion. At the center of the Crab Nebula lies the Crab Pulsar -- the collapsed core of the exploded star. The Crab Pulsar is a rapidly rotating neutron star -- an object only about six miles across, but containing more mass than our Sun. As it rotates at a rate of 30 times per second the Crab Pulsar's powerful magnetic field sweeps around, accelerating particles, and whipping them out into the nebula at speeds close to that of light. The blue glow in the inner part of the nebula -- light emitted by energetic electrons as they spiral through the Crab's magnetic field -- is powered by the Crab Pulsar. Credit: Jeff Hester and Paul Scowen (Arizona State University), and NASA

  19. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    Hall, B.; Burt, G.; Smith, J. D.A.; Rimmer, R.; Wang, H.; Delayen, J.; Calaga, R.

    2009-05-01

    In 2017 the LHC is envisioned to increase its luminosity via an upgrade. This upgrade is likely to require a large crossing angle hence a crab cavity is required to align the bunches prior to collision. There are two possible schemes for crab cavity implementation, global and local. In a global crab cavity the crab cavity is far from the IP and the bunch rotates back and forward as it traverses around the accelerator in a closed orbit. For this scheme a two-cell elliptical squashed cavity at 800 MHz is preferred. To avoid any potential beam instabilities all the parasitic modes of the cavities must be damped strongly, however crab cavities have lower order and same order modes in addition to the usual higher order modes and hence a novel damping scheme must be used to provide sufficient damping of these modes. In the local scheme two crab cavities are placed at each side of the IP two start and stop rotation of the bunches. This would require crab cavities much smaller transversely than in the global scheme but the frequency cannot be increased any higher due to the long bunch length of the LHC beam. This will require a novel compact crab cavity design. A superconducting version of a two rod coaxial deflecting cavity as a suitable design is proposed in this paper.

  20. Most Detailed Image of the Crab Nebula

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This new Hubble image -- one among the largest ever produced with the Earth-orbiting observatory -- shows the most detailed view so far of the entire Crab Nebula ever made. The Crab is arguably the single most interesting object, as well as one of the most studied, in all of astronomy. The image is the largest image ever taken with Hubble's WFPC2 workhorse camera.

    The Crab Nebula is one of the most intricately structured and highly dynamical objects ever observed. The new Hubble image of the Crab was assembled from 24 individual exposures taken with the NASA/ESA Hubble Space Telescope and is the highest resolution image of the entire Crab Nebula ever made.

  1. 50 CFR 680.6 - Crab economic data report (EDR).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab economic data report (EDR). 680.6... General § 680.6 Crab economic data report (EDR). Persons participating in the CR crab fisheries are... complete. Use these tables to complete the EDRs described in this section: Table 1, Crab...

  2. 50 CFR 680.6 - Crab economic data report (EDR).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab economic data report (EDR). 680.6... General § 680.6 Crab economic data report (EDR). Persons participating in the CR crab fisheries are... complete. Use these tables to complete the EDRs described in this section: Table 1, Crab...

  3. 50 CFR 680.6 - Crab economic data report (EDR).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab economic data report (EDR). 680.6... General § 680.6 Crab economic data report (EDR). Persons participating in the CR crab fisheries are... complete. Use these tables to complete the EDRs described in this section: Table 1, Crab...

  4. 50 CFR 622.247 - Landing golden crab intact.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Landing golden crab intact. 622.247... ATLANTIC Golden Crab Fishery of the South Atlantic Region § 622.247 Landing golden crab intact. The operator of a vessel that fishes in the EEZ is responsible for ensuring that golden crab on that vessel...

  5. 50 CFR 622.247 - Landing golden crab intact.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Landing golden crab intact. 622.247... ATLANTIC Golden Crab Fishery of the South Atlantic Region § 622.247 Landing golden crab intact. The operator of a vessel that fishes in the EEZ is responsible for ensuring that golden crab on that vessel...

  6. 25 CFR 1000.137 - What funds are included in an AFA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT Non-BIA Annual Self-Governance Compacts and Funding Agreements Funding § 1000.137 What funds... amount of funding the bureau would have spent for direct operations and indirect support and...

  7. 25 CFR 1000.137 - What funds are included in an AFA?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT Non-BIA Annual Self-Governance Compacts and Funding Agreements Funding § 1000.137 What funds... amount of funding the bureau would have spent for direct operations and indirect support and...

  8. Analysis of repeated signals during shell fights in the hermit crab Pagurus bernhardus

    PubMed Central

    Briffa, M.; Elwood, R. W.; Dick, J. T. A.

    1998-01-01

    Shell exchanges between hermit crabs may occur after a period of shell rapping, when the initiating or attacking crab brings its shell rapidly and repeatedly into contact with the shell of the non-initiator or defender, in a series of bouts. There are two opposing models of hermit crab shell exchange and the function of shell rapping. The negotiation model views shell exchange as a mutualistic activity, in which the initiator supplies information about the quality of its shell via the fundamental frequency of the rapping sound. The aggression model views shell rapping as either detrimental to the defending crab, or as providing it with information about the initiator's ability or motivation to continue, or both. The negotiation model makes no predictions about the temporal pattern of rapping, but under the aggression model it would be expected that crabs that rapped more vigorously would be more likely to effect an exchange. Repeating the signal could be expected under either model. Crabs that achieve an exchange rap more vigorously, rapping is more persistent when a clear gain in shell quality may be achieved, and the vigour is greater when the relative resource-holding potential (or 'fighting ability') is high. These findings support the aggression model rather than the negotiation model. Contrary to the predictions of game theory, crabs that do not effect an exchange appear to signal that they are about to give up. The data suggest that rapping is performed repeatedly because the accumulation of all of the performances acts as a signal of stamina.

  9. What brakes the Crab pulsar?

    NASA Astrophysics Data System (ADS)

    Čadež, A.; Zampieri, L.; Barbieri, C.; Calvani, M.; Naletto, G.; Barbieri, M.; Ponikvar, D.

    2016-03-01

    Context. Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. Aims: The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. Methods: We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. Results: From our analysis, we demonstrate that the power law index undergoes "instantaneous" changes at the time of observed jumps in rotational frequency (glitches). We find that the phase evolution of the Crab pulsar is dominated by a series of constant braking law episodes, with the braking index changing abruptly after each episode in the range of values between 2.1 and 2.6. Deviations from such a regular phase description behave as oscillations triggered by glitches and amount to fewer than 40 turns during the above period, in which the pulsar has made more than 2 × 1010 turns. Conclusions: Our analysis does not favor the explanation that glitches are connected to phenomena occurring in the interior of the pulsar. On the contrary, timing irregularities and changes in slow down rate seem to point to electromagnetic interaction of the pulsar with the surrounding environment.

  10. Detection by molecular hybridization of pap, afa, and sfa adherence systems in Escherichia coli strains associated with urinary and enteral infections.

    PubMed

    Archambaud, M; Courcoux, P; Labigne-Roussel, A

    1988-01-01

    The genetic determinants responsible for the adherence of Escherichia coli to uroepithelial cells have been identified in recent years by genetic and molecular methods. Specific DNA probes for each of the three operons which have been cloned so far (pap, afa, sfa/foc operons) have been used in colony hybridization experiments to detect the presence of each of these operons in the chromosomal DNA of 443 strains of E. coli; 186 strains were from patients with urinary tract infections (pyelonephritis, 106 strains; cystitis, 59; asymptomatic bacteriuria, 21) and 257 were strains from the stools of healthy subjects (61) or from patients with various enteral infections (196). E. coli strains harbouring the pap operon were found more frequently in the urine of patients with pyelonephritis (p less than 0.001) and cystitis (p less than 0.01) than in control stools. The presence of two operons (pap + afa) or (pap + sfa/foc) was only observed in uropathogenic strains (p less than 0.02). Pap and sfa/foc operons were never found in strains causing enteral infection; however, the afa operon was found in 7.6% of the enteropathogenic E. coli.

  11. Crab Crossing Consideration for MEIC 2

    SciTech Connect

    S. Ahmed, Y.S. Derbenev, G.A. Krafft, Y. Zhang, A. Castilla, J.R. Delayen, S.D. Silva

    2011-03-01

    Crab crossing of colliding electron and ion beams is essential for accommodating the ultra high bunch repetition frequency in the conceptual design of MEIC – a high luminosity polarized electron-ion collider at Jefferson Lab. The scheme eliminates parasitic beam-beam interactions and avoids luminosity reduction by restoring head-on collisions at interaction points. In this paper, we report simulation studies of beam dynamics with crab cavities for MEIC design. The detailed study involves full 3-D simulations of particle tracking through the various configurations of crab cavities for evaluating the performance. To gain insight, beam and RF dominated fields with other parametric studies will be presented in the paper.

  12. A large bubble around the Crab Nebula

    NASA Technical Reports Server (NTRS)

    Romani, Roger W.; Reach, William T.; Koo, Bon Chul; Heiles, Carl

    1990-01-01

    IRAS and 21 cm observations of the interstellar medium around the Crab nebula show evidence of a large bubble surrounded by a partial shell. If located at the canonical 2 kpc distance of the Crab pulsar, the shell is estimated to have a radius of about 90 pc and to contain about 50,000 solar masses of swept-up gas. The way in which interior conditions of this bubble can have important implications for observations of the Crab are described, and the fashion in which presupernova evolution of the pulsar progenitor has affected its local environment is described.

  13. Design of the ILC Crab Cavity System

    SciTech Connect

    Adolphsen, C.; Beard, C.; Bellantoni, L.; Burt, G.; Carter, R.; Chase, B.; Church, M.; Dexter, A.; Dykes, M.; Edwards, H.; Goudket, P; Jenkins, R.; Jones, R.M.; Kalinin, A.; Khabiboulline, T.; Ko, K.; Latina, A.; Li, Z.; Ma, L.; McIntosh, P.; Ng, C.; /SLAC /Daresbury /Fermilab /Cockcroft Inst. Accel. Sci. Tech. /CERN

    2007-08-15

    The International Linear Collider (ILC) has a 14 mrad crossing angle in order to aid extraction of spent bunches. As a result of the bunch shape at the interaction point, this crossing angle at the collision causes a large luminosity loss which can be recovered by rotating the bunches prior to collision using a crab cavity. The ILC baseline crab cavity is a 9-cell superconducting dipole cavity operating at a frequency of 3.9 GHz. In this paper the design of the ILC crab cavity and its phase control system, as selected for the RDR in February 2007 is described in fuller detail.

  14. 78 FR 40696 - Proposed Information Collection; Comment Request; Alaska Crab Cost Recovery

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ... Crab Cost Recovery AGENCY: National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION... and Aleutian Islands (BSAI) Crab includes the Crab Rationalization (CR) Program, a limited access system that allocates BSAI Crab resources among harvesters, processors, and coastal communities....

  15. Finding refuge: The estuarine distribution of the nemertean egg predator Carcinonemertes errans on the Dungeness crab, Cancer magister

    NASA Astrophysics Data System (ADS)

    Dunn, Paul H.; Young, Craig M.

    2013-12-01

    Parasites can significantly impact ecosystems by altering the distributions and population sizes of their host organisms. Some hosts are thought to find refuge from parasitism by entering habitats where their parasites cannot survive. The nemertean worm Carcinonemertes errans is an egg predator that infects the Dungeness crab, Cancer magister, throughout the host's range. To determine if C. magister experiences a refuge from C. errans within estuarine environments, we examined the distribution of C. errans on Dungeness crabs within Oregon's Coos Bay Estuary. Year-round sampling over a three-year period also allowed us to test for temporal variation in the parasite's distribution. We found that parasite prevalence, mean intensity, and parasite density of C. errans infecting C. magister varied along a clear estuarine gradient, with crabs nearest the ocean carrying the heaviest parasite loads. Larger crabs were more heavily infected with worms, and seasonal infection patterns were observed at some sites within the bay. Crabs sampled from coastal waters near the estuary carried significantly more worms than did crabs from the bay, suggesting that the estuary is acting as a spatiotemporal parasite refuge for this important fishery species.

  16. Monitoring the Crab Nebula with LOFT

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.

    2012-01-01

    From 2008-2010, the Crab Nebula was found to decline by 7% in the 15-50 keV band, consistently in Fermi GBM, INTEGRAL IBIS, SPI, and JEMX, RXTE PCA, and Swift BAT. From 2001-2010, the 15-50 keV flux from the Crab Nebula typically varied by about 3.5% per year. Analysis of RXTE PCA data suggests possible spectral variations correlated with the flux variations. I will present estimates of the LOFT sensitivity to these variations. Prior to 2001 and since 2010, the observed flux variations have been much smaller. Monitoring the Crab with the LOFT WFM and LAD will provide precise measurements of flux variations in the Crab Nebula if it undergoes a similarly active episode.

  17. Metals in horseshoe crabs from Delaware Bay.

    PubMed

    Burger, J; Dixon, C; Shukla, T; Tsipoura, N; Jensen, H; Fitzgerald, M; Ramos, R; Gochfeld, M

    2003-01-01

    We examined the concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the eggs, leg muscle, and apodeme (carapace musculature) in horseshoe crabs ( Limulus polyphemus) from eight places on the New Jersey and Delaware sides of Delaware Bay to determine whether there were locational differences. Although there were locational differences, the differences were not great. Further, contaminant levels were generally low. The levels of contaminants found in horseshoe crabs were well below those known to cause adverse effects in the crabs themselves or in organisms that consume them or their eggs. Contaminant levels have generally declined in the eggs of horseshoe crabs from 1993 to 2001, suggesting that contaminants are not likely to be a problem for secondary consumers or a cause of their decline.

  18. Transportation of Oyster Drills by Horseshoe "Crabs".

    PubMed

    Mackenzie, C L

    1962-07-01

    Horseshoe "crabs" (Limulus polyphemus) collected in New Haven Harbor, Long Island Sound, had large numbers of oyster drills attached to them. Since these animals migrate long distances, they may be important distributors of oyster drills.

  19. Wakefield Damping for the CLIC Crab Cavity

    SciTech Connect

    Ambattu, P.K.; Burt, G.; Dexter, A.C.; Carter, R.G.; Khan, V.; Jones, R.M.; Dolgashev, V.; /SLAC

    2011-12-01

    A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

  20. Identification of a novel clip domain serine proteinase (Sp-cSP) and its roles in innate immune system of mud crab Scylla paramamosain.

    PubMed

    Sun, Wanwei; Li, Zhongzhen; Wang, Shasha; Wan, Weisong; Wang, Shuqi; Wen, Xiaobo; Zheng, Huaiping; Zhang, Yueling; Li, Shengkang

    2015-11-01

    Clip domain serine proteinases and their homologs are involved in the innate immunity of invertebrates. To identify the frontline defense molecules against pathogenic infection, we isolated a novel clip domain serine proteinase (Sp-cSP) from the hemocytes of mud crab Scylla paramamosain. The full-length 1362 bp Sp-cSP contains a 1155 bp open reading frame (ORF) encoding 384 amino acids. Multiple alignment analysis showed that the putative amino acid sequence of Sp-cSP has about 52% and 51% identity with Pt-cSP2 (AFA42360) and Pt-cSP3 (AFA42361) from Portunus trituberculatus, respectively, while the similarity with other cSP sequences was lower than 30%. However, all cSP sequences possess a conserved clip domain at the N-terminal and a Tryp-SPc domain at the C-terminal. The genomic organization of Sp-cSP consists of nine exons and eight introns, with some introns containing one or more tandem repeats. RT-PCR results indicated that Sp-cSP transcripts were predominantly expressed in the subcuticular epidermis, muscle and mid-intestine, but barely detectable in the brain and heart. Further, Sp-cSP transcripts were significantly up-regulated after challenge with lipopolysaccharides (LPS), Vibrio parahaemolyticus, polyinosinic polycytidylic acid (PolyI:C) or white spot syndrome virus (WSSV). Moreover, in vitro, the recombinant Sp-cSP revealed a strong antimicrobial activity against a Gram-positive (Staphylococcus aureus) and four Gram-negative (V. parahaemolyticus, Vibrio alginolyticus, Escherichia coli, Aeromonas hydrophila) bacteria in a dose-dependent manner. Taken together, the acute-phase response to immune challenges and the antimicrobial activity assay indicate that Sp-cSP is a potent immune protector and plays an important role in host defense against pathogen invasion in S. paramamosain.

  1. Identification of a novel clip domain serine proteinase (Sp-cSP) and its roles in innate immune system of mud crab Scylla paramamosain.

    PubMed

    Sun, Wanwei; Li, Zhongzhen; Wang, Shasha; Wan, Weisong; Wang, Shuqi; Wen, Xiaobo; Zheng, Huaiping; Zhang, Yueling; Li, Shengkang

    2015-11-01

    Clip domain serine proteinases and their homologs are involved in the innate immunity of invertebrates. To identify the frontline defense molecules against pathogenic infection, we isolated a novel clip domain serine proteinase (Sp-cSP) from the hemocytes of mud crab Scylla paramamosain. The full-length 1362 bp Sp-cSP contains a 1155 bp open reading frame (ORF) encoding 384 amino acids. Multiple alignment analysis showed that the putative amino acid sequence of Sp-cSP has about 52% and 51% identity with Pt-cSP2 (AFA42360) and Pt-cSP3 (AFA42361) from Portunus trituberculatus, respectively, while the similarity with other cSP sequences was lower than 30%. However, all cSP sequences possess a conserved clip domain at the N-terminal and a Tryp-SPc domain at the C-terminal. The genomic organization of Sp-cSP consists of nine exons and eight introns, with some introns containing one or more tandem repeats. RT-PCR results indicated that Sp-cSP transcripts were predominantly expressed in the subcuticular epidermis, muscle and mid-intestine, but barely detectable in the brain and heart. Further, Sp-cSP transcripts were significantly up-regulated after challenge with lipopolysaccharides (LPS), Vibrio parahaemolyticus, polyinosinic polycytidylic acid (PolyI:C) or white spot syndrome virus (WSSV). Moreover, in vitro, the recombinant Sp-cSP revealed a strong antimicrobial activity against a Gram-positive (Staphylococcus aureus) and four Gram-negative (V. parahaemolyticus, Vibrio alginolyticus, Escherichia coli, Aeromonas hydrophila) bacteria in a dose-dependent manner. Taken together, the acute-phase response to immune challenges and the antimicrobial activity assay indicate that Sp-cSP is a potent immune protector and plays an important role in host defense against pathogen invasion in S. paramamosain. PMID:26272638

  2. 50 CFR Table 9 to Part 680 - Initial Issuance of Crab PQS by Crab QS Fishery

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Initial Issuance of Crab PQS by Crab QS Fishery 9 Table 9 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680,...

  3. 50 CFR Table 9 to Part 680 - Initial Issuance of Crab PQS by Crab QS Fishery

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Initial Issuance of Crab PQS by Crab QS Fishery 9 Table 9 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680,...

  4. 50 CFR Table 7 to Part 680 - Initial Issuance of Crab QS by Crab QS Fishery

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Initial Issuance of Crab QS by Crab QS Fishery 7 Table 7 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680, Table...

  5. 50 CFR Table 9 to Part 680 - Initial Issuance of Crab PQS by Crab QS Fishery

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Initial Issuance of Crab PQS by Crab QS Fishery 9 Table 9 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680,...

  6. 50 CFR Table 7 to Part 680 - Initial Issuance of Crab QS by Crab QS Fishery

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Initial Issuance of Crab QS by Crab QS Fishery 7 Table 7 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680, Table...

  7. 50 CFR Table 7 to Part 680 - Initial Issuance of Crab QS by Crab QS Fishery

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Initial Issuance of Crab QS by Crab QS Fishery 7 Table 7 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) SHELLFISH FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680, Table...

  8. 50 CFR Table 7 to Part 680 - Initial Issuance of Crab QS by Crab QS Fishery

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... used to calculate QS for each QS fishery is: 1. Bristol Bay red king crab (BBR) 4 years of the 5-year... through February 8, 2002. 4 years 3. Eastern Aleutian Islands golden king crab (EAG) 5 years of the 5-year... the last 3 seasons prior to June 10, 2002 in the Eastern Aleutian Island golden (brown) king...

  9. Perceptions of environmental changes and Lethargic crab disease among crab harvesters in a Brazilian coastal community

    PubMed Central

    2011-01-01

    Background Lethargic Crab Disease (LCD) has caused significant mortalities in the population of Ucides cordatus crabs in the Mucuri estuary in Bahia State, Brazil, and has brought social and economic problems to many crab-harvesting communities that depend on this natural resource. The present work examined the perceptions of members of a Brazilian crab harvesting community concerning environmental changes and the Lethargic Crab Disease. Methods Field work was undertaken during the period between January and April/2009, with weekly or biweekly field excursions during which open and semi-structured interviews were held with local residents in the municipality of Mucuri, Bahia State, Brazil. A total of 23 individuals were interviewed, all of whom had at least 20 years of crab-collecting experience in the study region. Key-informants (more experienced crab harvesters) were selected among the interviewees using the "native specialist" criterion. Results According to the collectors, LCD reached the Mucuri mangroves between 2004 and 2005, decimating almost all crab population in the area, and in 2007, 2008 and 2009 high mortalities of U. cordatus were again observed as a result of recurrences of this disease in the region. In addition to LCD, crabs were also suffering great stock reductions due to habitat degradation caused by deforestation, landfills, sewage effluents, domestic and industrial wastes and the introduction of exotic fish in the Mucuri River estuary. The harvesting community was found to have significant ecological knowledge about the functioning of mangrove swamp ecology, the biology of crabs, and the mass mortality that directly affected the economy of this community, and this information was largely in accordance with scientific knowledge. Conclusions The study of traditional knowledge makes it possible to better understand human interactions with the environment and aids in the elaboration of appropriate strategies for natural resource conservation

  10. Hermit to king, or hermit to all: multiple transitions to crab-like forms from hermit crab ancestors.

    PubMed

    Tsang, Ling Ming; Chan, Tin-Yam; Ahyong, Shane T; Chu, Ka Hou

    2011-10-01

    The Anomura presents the greatest degree of morphological disparity in the decapod Crustacea, with body forms ranging from the symmetrical and asymmetrical hermit crabs to squat lobsters and king crabs. The phylogeny of the anomurans has been fraught with controversy. Recent debate has focused primarily on the phenomenon of carcinization, the evolution of crab-like form from a non-crab-like ancestor, focused chiefly on derivation of king crabs from asymmetrical hermit crabs--the "hermit to king" hypothesis. We show by phylogenetic analysis of five nuclear protein-coding gene sequences that hermit crabs have a single origin, but surprisingly, that almost all other major clades and body forms within the Anomura, are derived from within the hermit crabs. The crab-like form and squat lobster form have each evolved at least twice from separate symmetrical hermit crab ancestors. In each case, a carcinization trend can be posited via a transition series from the initial symmetrical long-tailed hermit crab form, through the intermediate squat lobster or asymmetrical hermit crab form, to the final crab-like form. Adaptation to dextral shell habitation evolved at least twice, once in an exclusively deep-water clade and once in the common ancestor of all other asymmetrical hermit crabs (from which king crabs are derived). These remarkable cases of parallelism suggest considerable phenotypic flexibility within the hermit crab ground plan, with a general tendency toward carcinization. Rather than having a separate origin from other major clades, hermit crabs have given rise to most other major anomuran body types.

  11. 76 FR 59422 - Proposed Information Collection; Horseshoe Crab Tagging Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... crabs at their facilities. Limulus Amoebocyte Lysate is derived from crab blood, which has no synthetic substitute, and is used by pharmaceutical companies to test sterility of products. Finally,...

  12. Immunocompetent molecules and their response network in horseshoe crabs.

    PubMed

    Kawabata, Shun-ichiro

    2010-01-01

    Horseshoe crab hemocyte selectively responds to bacterial lipopolysaccharides (LPS), which depends critically on the proteolytic activity of the LPS-responsive serine protease zymogen factor C. In response to stimulation by LPS, the hemocyte secretes several kinds of immunocompetent proteins. The coagulation cascade triggered by LPS or beta-1,3-D-glucans (BDG) results in the formation of coagulin fibrils that are subsequently stabilized by transglutaminase (TGase)-dependent cross-linking. Invading pathogens are recognized and agglutinated by lectins and then killed by antimicrobial peptides. Moreover, LPS-triggered hemocyte exocytosis is enhanced by a feedback mechanism in which the antimicrobial peptides serve as endogenous mediators. Factor C also acts as an LPS-sensitive complement C3 convertase. In addition, a sub-cuticular epidermis-derived protein forms a TGase-stabilized mesh at sites of injury. Horseshoe crabs have a sophisticated innate immune response network that coordinately effects pathogen recognition and killing, prophenoloxidase activation, complement activation and TGase-dependent wound healing.

  13. 50 CFR 680.6 - Crab economic data report (EDR).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Crab economic data report (EDR). 680.6... General § 680.6 Crab economic data report (EDR). (a) Requirements. (1) Any owner or leaseholder of a vessel or processing plant, or a holder of a registered crab receiver permit that harvested,...

  14. 50 CFR 680.6 - Crab economic data report (EDR).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Crab economic data report (EDR). 680.6... General § 680.6 Crab economic data report (EDR). (a) Requirements. (1) Any owner or leaseholder of a vessel or processing plant, or a holder of a registered crab receiver permit that harvested,...

  15. Magnetic dissipation in the Crab nebula

    NASA Astrophysics Data System (ADS)

    Komissarov, Serguei S.

    2013-01-01

    Magnetic dissipation is frequently invoked as a way of powering the observed emission of relativistic flows in Gamma-ray bursts and active galactic nuclei. Pulsar Wind Nebulae provide closer to home cosmic laboratories which can be used to test the hypothesis. To this end, we reanalyze the observational data on the spindown power of the Crab pulsar, energetics of the Crab nebula and its magnetic field. We show that unless the magnetic inclination angle of the Crab pulsar is very close to 90 degrees the overall magnetization of the striped wind after total dissipation of its stripes is significantly higher than that deduced in the Kennel-Coroniti model and recent axisymmetric simulations of Pulsar Wind Nebulae. On the other hand, higher wind magnetization is in conflict with the observed low magnetic field of the Crab nebula, unless it is subject to efficient dissipation inside the nebula as well. For the likely inclination angle of 45 degrees the data require magnetic dissipation on the time-scale of about 80 years, which is short compared to the lifetime of the nebula but long compared to the time-scale of Crab's gamma-ray flares.

  16. Oesophageal chemoreceptors of blue crabs, Callinectes sapidus, sense chemical deterrents and can block ingestion of food.

    PubMed

    Aggio, Juan F; Tieu, Ryan; Wei, Amy; Derby, Charles D

    2012-05-15

    Decapod crustaceans such as blue crabs possess a variety of chemoreceptors that control different stages of the feeding process. All these chemoreceptors are putative targets for feeding deterrents that cause animals to avoid or reject otherwise palatable food. As a first step towards characterizing the chemoreceptors that mediate the effect of deterrents, we used a behavioral approach to investigate their precise location. Data presented here demonstrate that chemoreceptors located on the antennules, pereiopods and mouthparts do not mediate the food-rejection effects of a variety of deterrents, both natural and artificial to crabs. Crabs always searched for deterrent-laced food and took it to their oral region. The deterrent effect was manifested as either rejection or extensive manipulation, but in both cases crabs bit the food. The biting behavior is relevant because the introduction of food into the oral cavity ensured that the deterrents gained access to the oesophageal taste receptors, and so we conclude that they are the ones mediating rejection. Additional support comes from the fact that a variety of deterrent compounds evoked oesophageal dilatation, which is mediated by oesophageal receptors and has been linked to food rejection. Further, there is a positive correlation between a compound's ability to elicit rejection and its ability to evoke oesophageal dilatation. The fact that deterrents do not act at a distance is in accordance with the limited solubility of most known feeding deterrents, and likely influences predator-prey interactions and their outcome: prey organisms will be attacked and bitten before deterrents become relevant.

  17. Crab Waist Collision at DAFNE

    SciTech Connect

    Milardi, C.; Alesini, D.; Biagini, M.E.; Boni, R.; Boscolo, M.; Bossi, F.; Buonomo, B.; Clozza, A.; Delle Monache, G.; Demma, T.; Di Pasquale, E.; Di Pirro, G.; Drago, A.; Gallo, A.; Ghigo, A.; Guiducci, S.; Ligi, C.; Marcellini, F.; Mazzitelli, G.; Murtas, F.; Pellegrino, L.; /Frascati /Novosibirsk, IYF /CERN /INFN, Cosenza /INFN, Rome /KEK, Tsukuba /Orsay, LAL /Rome U. /Pisa U. /INFN, Pisa /INFN, Rome3 /SLAC

    2011-11-30

    DAFNE is an accelerator complex consisting of a double ring lepton collider working at the c.m. energy of the {Phi}-resonance (1.02 GeV) and an injection system. In its original configuration the collider consisted of two independent rings, each {approx}97 m long, sharing two 10 m long interaction regions (IR1 and IR2) where the KLOE and FINUDA or DEAR detectors were respectively installed. A full energy injection system, including an S-band linac, 180 m long transfer lines and an accumulator/damping ring, provides fast and high efficiency electron positron injection also in topping-up mode during collisions. Recently the DAFNE collider has been upgraded in order to implement a new collision scheme based on large Piwinski angle and cancellation of the synchro-betatron resonances by means of electromagnetic sextupoles (Crab-Waist compensation). The novel approach has proved to be effective in improving beam-beam interaction and collider luminosity.

  18. Prevalence and sources of Listeria monocytogenes in blue crab (Callinectus sapidus) meat and blue crab processing plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seven blue crab processing plants were sampled to determine the prevalence and sources of Listeria spp. and L. monocytogenes for two years (2006-2007). A total of 488 raw crab, 624 crab meat, and 624 environmental samples were tested by molecular and culture-based standard methods. Presumptive Liste...

  19. Tachyplesin, a class of antimicrobial peptide from the hemocytes of the horseshoe crab (Tachypleus tridentatus). Isolation and chemical structure.

    PubMed

    Nakamura, T; Furunaka, H; Miyata, T; Tokunaga, F; Muta, T; Iwanaga, S; Niwa, M; Takao, T; Shimonishi, Y

    1988-11-15

    A cationic peptide, designated tachyplesin, was isolated from acid extracts of horseshoe crab (Tachypleus tridentatus) hemocyte debris. It consists of 17 residues and the structure determined by Edman degradation is: (formula; see text) The carboxyl-terminal end of this peptide was identified as arginine alpha-amide, and the whole sequence including the alpha-amide was also confirmed by fast atom bombardment mass spectrometry, indicating a mass value of 2263. Tachyplesin inhibits growth of both Gram-negative and -positive bacteria at low concentrations and formed a complex with bacterial lipopolysaccharide. Tachyplesin seems likely to act as antimicrobial peptide for self-defense in the horseshoe crab against invading microorganisms.

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

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

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

  1. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Pacific Southwest): Brown rock crab, red rock crab, and yellow crab

    SciTech Connect

    Carroll, J.C. ); Winn, R.N. )

    1989-12-01

    Species profiles are literature summaries of the taxonomy, morphology, distribution, life history, habitats, and environmental requirements of coastal species of fishes and aquatic invertebrates. They are designed to assist in environmental impact assessment. Rock crab'' is the common name designating three similar species of edible crabs: brown rock crab (Cancer antennarius), red rock crab (C. productus), and yellow crab (C. anthonyi). The three species co-occur in shallow coastal waters throughout the Pacific Southwest region. The yellow crab is most common in southern California on sand substrate, and the red rock crab in northernmost areas on rock or gravel substrates; the brown rock crab occurs on rock or sand substrates in all areas. Rock crabs are sought commercially to fill an increasing market demand for whole crabs that approached 2 million pounds annually in 1986. Most of the catch comes from the region of Morro Bay south to Los Angeles, including the Channel Islands. Egg-bearing females are commonly found during winter, although they may occur throughout the year.Rock crabs go through five zoeal stages and one megalopal stage during a larval period that generally requires 90--120 days. Metamorphosis and settlement of the first crab stage is on either sand or rock, and crabs may reach maturity within 1--2 years. All three species are predators on a variety of shelled mollusks, but are also considered scavengers. They are a major food for many commercially and recreationally important fishes, as well as for the threatened southern sea otter, Enhydra lutris. 63 refs., 6 figs., 1 tab.

  2. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    B. Hall, G. Burt, C. Lingwood, R. Rimmer, H. Wang

    2010-05-23

    The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.

  3. Novel Geometries for the LHC Crab Cavity

    SciTech Connect

    B. Hall,G. Burt,C. Lingwood,Robert Rimmer,Haipeng Wang; Hall, B.; Burt, G.; Lingwood, C.; Rimmer, Robert; Wang, Haipeng

    2010-05-01

    The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.

  4. Distortion of Crabbed Bunch Due to the Electron Cloud

    SciTech Connect

    Wang, L; Raubenheimer, T.; /SLAC

    2008-05-28

    In order to improve the luminosity, two crab cavities have been installed in KEKB HER and LER [1]. Since there is only one crab cavity in each ring, the crab cavity generates a horizontally titled bunch along the whole ring. The achieved specific luminosity with crabbed bunch is higher, but it is not as high as that from beam-beam simulation [2]. One of the suspicions is the electron cloud. The electron cloud in LER (positron beam) may distort the crabbed bunch and cause the luminosity drop. This note briefly estimates the bunch shape distortion due to the electron cloud in KEKB LER.

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

    PubMed

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

    2014-02-01

    Spontaneous alternation refers to the tendency of organisms to explore places that they have least recently visited. Our previous work showed that alternation performance of Carcinus maenas (invasive European green crab) was significantly higher than Callinectes sapidus (native blue crab), and chance level performance (Ramey, P. A., Teichman, E., Oleksiak, J., & Balcı, F. [2009]. Spontaneous alternation in marine crabs: Invasive versus native species. Behavioural Processes, 82, 51-55.). In the current study, we first tested the robustness of these findings in the absence of visual cues, longer test durations, and wider maze dimensions. These manipulations enabled us to determine whether these two crab species relied on the visual cues provided during the spontaneous alternation task in our prior work, and allowed for better characterization of their exploratory activity in the maze. Our original findings were reproduced in the present study under these new task conditions, suggesting no role for visual cues during alternation, and emphasizing the robustness and generalizability of the corresponding interspecies differences in alternation performance. We also tested whether the lower alternation performance of C. sapidus also applied to another native crab species, Uca pugnax (fiddler crab). Spontaneous alternation performance of U. pugnax was significantly lower than C. maenas but indistinguishable from C. sapidus. Finally, we examined whether the potentially higher inherent risk-sensitivity of C. sapidus could have contributed to their lower alternation performance by testing C. maenas in the presence of a larger natural predator (stressor). Higher risk sensitivity presumably induced by the stressor led to locomotor activity patterns that better resembled those of C. sapidus, however the resultant reduction in alternation performance was not statistically significant. PMID:24060243

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

    PubMed

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

    2014-02-01

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

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

    PubMed Central

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

    2011-01-01

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

  8. Evolution of metabolomics profile of crab paste during fermentation.

    PubMed

    Chen, Daian; Ye, Yangfang; Chen, Juanjuan; Yan, Xiaojun

    2016-02-01

    Crab paste is regularly consumed by people in the coastal area of China. The fermentation time plays a key role on the quality of crab paste. Here, we investigated the dynamic evolution of metabolite profile of crab paste during fermentation by combined use of NMR spectroscopy and multivariate data analysis. Our results showed that crab paste quality was significantly affected by fermentation. The quality change was manifested in the decline of lactate, betaine, taurine, trimethylamine-N-oxide, trigonelline, inosine, adenosine diphosphate, and 2-pyridinemethanol, and in the fluctuation of a range of amino acids as well as in the accumulation of glutamate, sucrose, formate, acetate, trimethylamine, and hypoxanthine. Trimethylamine production and its increased level with fermentation could be considered as a freshness index of crab paste. These results contribute to quality assessment of crab paste and confirm the metabolomics technique as a useful tool to provide important information on the crab paste quality.

  9. Modeling Crabbing Dynamics in an Electron-Ion Collider

    SciTech Connect

    Castilla, Alejandro; Morozov, Vasiliy S.; Satogata, Todd J.; Delayen, Jean R.

    2015-09-01

    A local crabbing scheme requires π/2 (mod π) horizontal betatron phase advances from an interaction point (IP) to the crab cavities on each side of it. However, realistic phase advances generated by sets of quadrupoles, or Final Focusing Blocks (FFB), between the crab cavities located in the expanded beam regions and the IP differ slightly from π/2. To understand the effect of crabbing on the beam dynamics in this case, a simple model of the optics of the Medium Energy Electron-Ion Collider (MEIC) including local crabbing was developed using linear matrices and then studied numerically over multiple turns (1000 passes) of both electron and proton bunches. The same model was applied to both local and global crabbing schemes to determine the linear-order dynamical effects of the synchro-betatron coupling induced by crabbing.

  10. Primary Prevention Programme for Burnout-Endangered Teachers: Follow-Up Effectiveness of a Combined Group and Individual Intervention of AFA Breathing Therapy

    PubMed Central

    Loew, Thomas; Hornung, Regina; Cojocaru, Laura; Lahmann, Claas; Tritt, Karin

    2013-01-01

    Background. Early retirement of teachers due to burnout is frequent in Germany. In this study short- and medium-term effects of AFA breathing therapy were evaluated. Methods. This study was designed as a longitudinal controlled intervention design with four points of measurements: before assessment (T1), after intervention (T2), three months (follow up 1) (T3) after intervention, and six months (follow up 2) after intervention (T4). The intervention lasted a total of 11 weeks (weekly group therapy for eight weeks and three weeks of individual breathing session). The effects of intervention were measured with the questionnaire “work-related behaviour and experience Patterns” (AVEM) at four times. Results. In the intervention group 64 teachers and in the self-selected control group 27 teachers were included. The AVEM scales “subjective significance of work” and “professional ambition” changed over time and within both groups (interaction effect). Significant improvements over the four measurements were observed in the intervention group in two AVEM scales: “emotional distancing” (F = 6.3; P < 0.01) and “balance and mental stability” (F = 4.4; P < 0.02). Conclusions. AFA breathing therapy showed short- and medium-term effects in the intervention group over four points of measurements. It may be assumed that breath therapy supports teachers in resisting occupational demand. PMID:24069056

  11. Conformations of phenylalanine in the tripeptides AFA and GFG probed by combining MD simulations with NMR, FTIR, polarized Raman, and VCD spectroscopy.

    PubMed

    Pizzanelli, Silvia; Forte, Claudia; Monti, Susanna; Zandomeneghi, Giorgia; Hagarman, Andrew; Measey, Thomas J; Schweitzer-Stenner, Reinhard

    2010-03-25

    Conformational properties of small, flexible peptides are a matter of ongoing interest since they can be considered as models for unfolded proteins. However, the investigation of the conformations of small peptides is challenging as they are ensembles of rapidly interconverting conformers; moreover, the different methods used are prone to different approximations and errors. In order to obtain more reliable results, it is prudent to combine different techniques; here, molecular dynamics (MD) simulations together with nuclear magnetic resonance (NMR), Fourier transform IR (FTIR), polarized Raman, and vibrational circular dichroism (VCD) measurements were used to study the conformational propensity of phenylalanine in the tripeptides AFA and GFG, motivated by the relevance of phenylalanine for the self-aggregation of peptides. The results of this analysis indicate that the F residue predominantly populates the beta-strand (beta) and polyproline II (PPII) conformations in both AFA and GFG. However, while phenylalanine exhibits a propensity for beta-strand conformations in GFG (0.40 < or = beta population < or = 0.69 and 0.29 < or = PPII population < or = 0.42), the substitution of terminal glycines with alanine residues induces a higher population of PPII (0.31 < or = beta population < or = 0.50 and 0.37 < or = PPII population < or = 0.57).

  12. 50 CFR 648.263 - Red crab possession and landing restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Red crab possession and landing... Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.263 Red crab possession and landing restrictions. (a) Vessels issued limited access red crab permits. (1) (2) Conversion to whole crab weight....

  13. 50 CFR 648.263 - Red crab possession and landing restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Red crab possession and landing... Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.263 Red crab possession and landing restrictions. (a) Vessels issued limited access red crab permits. (1) (2) Conversion to whole crab weight....

  14. 50 CFR 648.263 - Red crab possession and landing restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Red crab possession and landing... Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.263 Red crab possession and landing restrictions. (a) Vessels issued limited access red crab permits. (1) (2) Conversion to whole crab weight....

  15. 50 CFR 648.263 - Red crab possession and landing restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Red crab possession and landing... Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.263 Red crab possession and landing restrictions. (a) Vessels issued limited access red crab permits. (1) (2) Conversion to whole crab weight....

  16. HUBBLE CAPTURES DYNAMICS OF CRAB NEBULA

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A new sequence of Hubble Space Telescope images of the remnant of a tremendous stellar explosion is giving astronomers a remarkable look at the dynamic relationship between the tiny Crab Pulsar and the vast nebula that it powers. This picture shows a Hubble Space Telescope image of the inner parts of the Crab. The pulsar itself is visible as the left of the pair of stars near the center of the frame. Surrounding the pulsar is a complex of sharp knots and wisp-like features. This image is one of a sequence of Hubble images taken over the course of several months. This sequence shows that the inner part of the Crab Nebula is far more dynamic than previously understood. The Crab literally 'changes it stripes' every few days as these wisps stream away from the pulsar at half the speed of light. The Hubble Space Telescope photo was taken Nov. 5, 1995 by the Wide Field and Planetary Camera 2 at a wavelength of around 550 nanometers, in the middle of the visible part of the electromagnetic spectrum. Credit: Jeff Hester and Paul Scowen (Arizona State University), and NASA

  17. Power coupler for the ILC crab cavity

    SciTech Connect

    Burt, G.; Dexter, A.; Jenkins, R.; Beard, C.; Goudket, P.; McIntosh, P.A.; Bellantoni, Leo; /Fermilab

    2007-06-01

    The ILC crab cavity will require the design of an appropriate power coupler. The beam-loading in dipole mode cavities is considerably more variable than accelerating cavities, hence simulations have been performed to establish the required external Q. Simulations of a suitable coupler were then performed and were verified using a normal conducting prototype with variable coupler tips.

  18. [Biologically Active Peptides of King Crab Hepatopancreas].

    PubMed

    Bogdanov, V V; Berezin, B B; Il'ina, A P; Yamskova, V P; Yamskov, I A

    2015-01-01

    Substances of a peptide nature isolated from the hepatopancreas of the king crab Paralithodes camtschaticus exhibited physicochemical properties and membranotropic and specific activities similar to those of membranotropic homeostatic tissue-specific bioregulators previously found in different mammalian and plant tissues. Their biological effect on vertebrate tissues was demonstrated on a model of roller organotypic cultivation of Pleurodeles waltl newt liver tissue. PMID:26353409

  19. A HYPERSPECTRAL VIEW OF THE CRAB NEBULA

    SciTech Connect

    Charlebois, M.; Drissen, L.; Bernier, A.-P.; Grandmont, F.; Binette, L. E-mail: ldrissen@phy.ulaval.c

    2010-05-15

    We have obtained spatially resolved spectra of the Crab nebula in the spectral ranges 450-520 nm and 650-680 nm, encompassing the H{beta}, [O III] {lambda}4959, {lambda}5007, H{alpha}, [N II] {lambda}6548, {lambda}6584, and [S II] {lambda}6717, {lambda}6731 emission lines, with the imaging Fourier transform spectrometer SpIOMM at the Observatoire du Mont-Megantic's 1.6 m telescope. We first compare our data with published observations obtained either from a Fabry-Perot interferometer or from a long-slit spectrograph. Using a spectral deconvolution technique similar to the one developed by Cadez et al., we identify and resolve multiple emission lines separated by large Doppler shifts and contained within the rapidly expanding filamentary structure of the Crab. This allows us to measure important line ratios, such as [N II]/H{alpha}, [S II]/H{alpha}, and [S II] {lambda}6717 /[S II] {lambda}6731 of individual filaments, providing a new insight on the SE-NW asymmetry in the Crab. From our analysis of the spatial distribution of the electronic density and of the respective shocked versus photoionized gas components, we deduce that the skin-less NW region must have evolved faster than the rest of the nebula. Assuming a very simple expansion model for the ejecta material, our data provide us with a complete tridimensional view of the Crab.

  20. The CMS Remote Analysis Builder (CRAB)

    SciTech Connect

    Spiga, D.; Cinquilli, M.; Servoli, L.; Lacaprara, S.; Fanzago, F.; Dorigo, A.; Merlo, M.; Farina, F.; Fanfani, A.; Codispoti, G.; Bacchi, W.; /INFN, Bologna /Bologna U /CERN /INFN, CNAF /INFN, Trieste /Fermilab

    2008-01-22

    The CMS experiment will produce several Pbytes of data every year, to be distributed over many computing centers geographically distributed in different countries. Analysis of this data will be also performed in a distributed way, using grid infrastructure. CRAB (CMS Remote Analysis Builder) is a specific tool, designed and developed by the CMS collaboration, that allows a transparent access to distributed data to end physicist. Very limited knowledge of underlying technicalities are required to the user. CRAB interacts with the local user environment, the CMS Data Management services and with the Grid middleware. It is able to use WLCG, gLite and OSG middleware. CRAB has been in production and in routine use by end-users since Spring 2004. It has been extensively used in studies to prepare the Physics Technical Design Report (PTDR) and in the analysis of reconstructed event samples generated during the Computing Software and Analysis Challenge (CSA06). This involved generating thousands of jobs per day at peak rates. In this paper we discuss the current implementation of CRAB, the experience with using it in production and the plans to improve it in the immediate future.

  1. Ocean acidification impairs crab foraging behaviour

    PubMed Central

    Dodd, Luke F.; Grabowski, Jonathan H.; Piehler, Michael F.; Westfield, Isaac; Ries, Justin B.

    2015-01-01

    Anthropogenic elevation of atmospheric CO2 is driving global-scale ocean acidification, which consequently influences calcification rates of many marine invertebrates and potentially alters their susceptibility to predation. Ocean acidification may also impair an organism's ability to process environmental and biological cues. These counteracting impacts make it challenging to predict how acidification will alter species interactions and community structure. To examine effects of acidification on consumptive and behavioural interactions between mud crabs (Panopeus herbstii) and oysters (Crassostrea virginica), oysters were reared with and without caged crabs for 71 days at three pCO2 levels. During subsequent predation trials, acidification reduced prey consumption, handling time and duration of unsuccessful predation attempt. These negative effects of ocean acidification on crab foraging behaviour more than offset any benefit to crabs resulting from a reduction in the net rate of oyster calcification. These findings reveal that efforts to evaluate how acidification will alter marine food webs should include quantifying impacts on both calcification rates and animal behaviour. PMID:26108629

  2. Ammonia excretion in aquatic and terrestrial crabs.

    PubMed

    Weihrauch, Dirk; Morris, Steve; Towle, David W

    2004-12-01

    The excretory transport of toxic ammonia across epithelia is not fully understood. This review presents data combined with models of ammonia excretion derived from studies on decapod crabs, with a view to providing new impetus to investigation of this essential issue. The majority of crabs preserve ammonotely regardless of their habitat, which varies from extreme hypersaline to freshwater aquatic environments, and ranges from transient air exposure to obligate air breathing. Important components in the excretory process are the Na+/K+(NH4+)-ATPase and other membrane-bound transport proteins identified in many species, an exocytotic ammonia excretion mechanism thought to function in gills of aquatic crabs such as Carcinus maenas, and gaseous ammonia release found in terrestrial crabs, such as Geograpsus grayi and Ocypode quadrata. In addition, this review presents evidence for a crustacean Rhesus-like protein that shows high homology to the human Rhesus-like ammonia transporter both in its amino acid sequence and in its predicted secondary structure. PMID:15579545

  3. Tarantula and Hermit Crab Emergency Care.

    PubMed

    Marnell, Cinthia

    2016-05-01

    Tarantulas and hermit crabs are commonly kept pets and are underappreciated in veterinary medicine. Safe handling, biology and husbandry, diagnostic techniques, anesthesia, fluid therapy, disorders, and euthanasia are covered in this article. Current research is applied to these topics to keep practitioners abreast with the best medicine for these creatures. PMID:27131164

  4. Search for excess showers from Crab Nebula

    NASA Technical Reports Server (NTRS)

    Kirov, I. N.; Stamenov, J. N.; Ushev, S. Z.; Janminchev, V. D.; Aseikin, V. S.; Nikolsky, S. I.; Nikolskaja, N. M.; Yakovlev, V. I.; Morozov, A. E.

    1985-01-01

    The arrival directions of muon poor showers registrated in the Tien Shan experiment during an effective running time about I,8.IO(4)h were analyzed. It is shown that there is a significant excess of these showers coming the direction of Crab Nebula.

  5. Corneal laceration caused by river crab

    PubMed Central

    Vinuthinee, Naidu; Azreen-Redzal, Anuar; Juanarita, Jaafar; Zunaina, Embong

    2015-01-01

    A 5-year-old boy presented with right eye pain associated with tearing and photophobia of 1-day duration. He gave a history of playing with a river crab when suddenly the crab clamped his fingers. He attempted to fling the crab off, but the crab flew and hit his right eye. Ocular examination revealed a right eye corneal ulcer with clumps of fibrin located beneath the corneal ulcer and 1.6 mm level of hypopyon. At presentation, the Seidel test was negative, with a deep anterior chamber. Culture from the corneal scrapping specimen grew Citrobacter diversus and Proteus vulgaris, and the boy was treated with topical gentamicin and ceftazidime eyedrops. Fibrin clumps beneath the corneal ulcer subsequently dislodged, and revealed a full-thickness corneal laceration wound with a positive Seidel test and shallow anterior chamber. The patient underwent emergency corneal toileting and suturing. Postoperatively, he was treated with oral ciprofloxacin 250 mg 12-hourly for 1 week, topical gentamicin, ceftazidime, and dexamethasone eyedrops for 4 weeks. Right eye vision improved to 6/9 and 6/6 with pinhole at the 2-week follow-up following corneal suture removal. PMID:25678769

  6. Ocean acidification impairs crab foraging behaviour.

    PubMed

    Dodd, Luke F; Grabowski, Jonathan H; Piehler, Michael F; Westfield, Isaac; Ries, Justin B

    2015-07-01

    Anthropogenic elevation of atmospheric CO2 is driving global-scale ocean acidification, which consequently influences calcification rates of many marine invertebrates and potentially alters their susceptibility to predation. Ocean acidification may also impair an organism's ability to process environmental and biological cues. These counteracting impacts make it challenging to predict how acidification will alter species interactions and community structure. To examine effects of acidification on consumptive and behavioural interactions between mud crabs (Panopeus herbstii) and oysters (Crassostrea virginica), oysters were reared with and without caged crabs for 71 days at three pCO2 levels. During subsequent predation trials, acidification reduced prey consumption, handling time and duration of unsuccessful predation attempt. These negative effects of ocean acidification on crab foraging behaviour more than offset any benefit to crabs resulting from a reduction in the net rate of oyster calcification. These findings reveal that efforts to evaluate how acidification will alter marine food webs should include quantifying impacts on both calcification rates and animal behaviour.

  7. Phoretic interaction between the kangaroo leech Marsupiobdella africana (Hirudinea: Glossiphoniidae) and the cape river crab Potamonautes perlatus (Decapoda: Potamonautidae)☆

    PubMed Central

    Badets, Mathieu; Preez, Louis Du

    2013-01-01

    The South African leech Marsupiobdella africana is a temporary ectoparasite of the amphibian Xenopus laevis, has a phoretic association with a freshwater crab Potamonautes perlatus, and exhibits advanced parental care by incubating its offspring in a brood pouch. Because phoretic associations are usually regarded to favor the phoront’s dispersion, its occurrence within the biology of a parasitic species reflects an intimate context of interactions. In addition to phoresy, attachment to the crab may confer other advantages pertaining to offspring development and predator avoidance, dispersion and the parasitic life cycle. Two ponds where amphibian and crab hosts co-occur were sampled twice a month for a period of 1 year. The population dynamics of the leeches and their use of specific microhabitats as attachment sites on the crabs were also investigated. Results indicate a direct relationship between intra-specific variation in the sex ratio among captured crab hosts and the number of leeches recruited over time. The attachments to specific microhabitats on the hard surfaces of the host suggest a proximal proximate anti-predatory strategy. Finally, the importance of oxygen accessibility for the offspring development has been investigated experimentally. Results revealed a remarkable network of interactions linking all partners of this system raising the question as to whether the crabs merely act as a vehicle or play a role within the parasitic life cycle. PMID:24918071

  8. Accumulation and depuration of pectenotoxins in brown crab Cancer pagurus

    NASA Astrophysics Data System (ADS)

    Li, Zhaoxin

    2009-06-01

    Pectenotoxins (PTXs) are a group of marine algal toxins. In this study, the accumulation and depuration of pectenotoxins in brown crab Cancer pagurus were investigated. Crabs were fed with toxic blue mussels Mytilus edulis for 21 days and then depurated for 42 days. Toxins were extracted with methanol from the digestive glands of contaminated crabs, uncontaminated crabs (control group) and from blue mussels for comparison. Extracts were analyzed by liquid chromatograph coupled with tandem mass spectrometry (LC-MS-MS). The concentrations of PTX-2, PTX-2 SA, 7- epi-PTX-2 SA, and PTX-12 were analyzed in two batches of toxic blue mussels and the crabs. A one-compartment model was applied to describe the depuration of PTXs. The half-life of PTXs was estimated to be 6-7.5 days. After depuration for 42 days, the amount of PTXs measured in the crab digestive glands was less than 1 μg/kg.

  9. Ghost fishing activity in derelict blue crab traps in Louisiana.

    PubMed

    Anderson, Julie A; Alford, Amy B

    2014-02-15

    Derelict crab traps impact the coastal ecosystem through continued catch of target species and species of conservation, economic, or recreational importance. During volunteer-supported crab trap cleanups in 2012 and 2013, we quantified ghost fishing activity in derelict crab traps in coastal Louisiana through a citizen scientist program. Volunteers removed 3607 derelict traps during these events, and over 65% of traps analyzed by citizen scientists were actively ghost fishing. Additionally, volunteers identified 19 species enmeshed in derelict traps, including a combination of fresh and saltwater species. We also detected a significant difference in the number of blue crab in actively ghost fishing derelict traps across removal locations with estimated catches varying between 2.4 and 3.5 crabs/trap. Our instantaneous estimates of ghost fishing activity are greater than those previously thought in Louisiana, further justifying current derelict crab trap prevention and removal extension and outreach programs in Louisiana and throughout the Gulf of Mexico.

  10. Determination of key environmental factors responsible for distribution patterns of fiddler crabs in a tropical mangrove ecosystem.

    PubMed

    Mokhtari, Mohammad; Ghaffar, Mazlan Abd; Usup, Gires; Cob, Zaidi Che

    2015-01-01

    In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites within the mudflats of Sepang-Lukut mangrove forest. Temperature, porewater salinity, organic matter, water content, carbon and nitrogen content, porosity, chlorophyll content, pH, redox potential, sediment texture and heavy metals were determined in each 1 m2 quadrate. Pearson correlation indicated that all sediment properties except pH and redox potential were correlated with sediment grain size. Canonical correspondence analysis (CCA) indicated that Uca paradussumieri was negatively correlated with salinity and redox potential. Sand dwelling species, Uca perplexa and Uca annulipes, were highly dependent on the abundance of 250 μm and 150 μm grain size particles in the sediment. Canonical Discriminative Analysis (CDA) indicated that variation in sediment grain size best explained where each crab species was most abundant. Moreover, U. paradussumieri commonly occupies muddy substrates of low shore, while U. forcipata lives under the shade of mangrove trees. U. annulipes and U. perplexa with the high number of spoon tipped setae on their second maxiliped are specialized to feed on the sandy sediments. U. rosea and U. triangularis are more common on muddy sediment with high sediment density. In conclusion, sediment grain size that influences most sediment properties acts as a main factor responsible for sediment heterogeneity. In this paper, the correlation between fiddler crab species and environmental parameters, as well as the interaction between sediment characteristics, was explained in order to define the important environmental factors in fiddler crab distributions. PMID

  11. Determination of key environmental factors responsible for distribution patterns of fiddler crabs in a tropical mangrove ecosystem.

    PubMed

    Mokhtari, Mohammad; Ghaffar, Mazlan Abd; Usup, Gires; Cob, Zaidi Che

    2015-01-01

    In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites within the mudflats of Sepang-Lukut mangrove forest. Temperature, porewater salinity, organic matter, water content, carbon and nitrogen content, porosity, chlorophyll content, pH, redox potential, sediment texture and heavy metals were determined in each 1 m2 quadrate. Pearson correlation indicated that all sediment properties except pH and redox potential were correlated with sediment grain size. Canonical correspondence analysis (CCA) indicated that Uca paradussumieri was negatively correlated with salinity and redox potential. Sand dwelling species, Uca perplexa and Uca annulipes, were highly dependent on the abundance of 250 μm and 150 μm grain size particles in the sediment. Canonical Discriminative Analysis (CDA) indicated that variation in sediment grain size best explained where each crab species was most abundant. Moreover, U. paradussumieri commonly occupies muddy substrates of low shore, while U. forcipata lives under the shade of mangrove trees. U. annulipes and U. perplexa with the high number of spoon tipped setae on their second maxiliped are specialized to feed on the sandy sediments. U. rosea and U. triangularis are more common on muddy sediment with high sediment density. In conclusion, sediment grain size that influences most sediment properties acts as a main factor responsible for sediment heterogeneity. In this paper, the correlation between fiddler crab species and environmental parameters, as well as the interaction between sediment characteristics, was explained in order to define the important environmental factors in fiddler crab distributions.

  12. Determination of Key Environmental Factors Responsible for Distribution Patterns of Fiddler Crabs in a Tropical Mangrove Ecosystem

    PubMed Central

    Mokhtari, Mohammad; Ghaffar, Mazlan Abd; Usup, Gires; Cob, Zaidi Che

    2015-01-01

    In tropical regions, different species of fiddler crabs coexist on the mangrove floor, which sometimes makes it difficult to define species-specific habitat by visual inspection. The aim of this study is to find key environmental parameters which affect the distribution of fiddler crabs and to determine the habitats in which each species was most abundant. Crabs were collected from 19 sites within the mudflats of Sepang-Lukut mangrove forest. Temperature, porewater salinity, organic matter, water content, carbon and nitrogen content, porosity, chlorophyll content, pH, redox potential, sediment texture and heavy metals were determined in each 1 m2 quadrate. Pearson correlation indicated that all sediment properties except pH and redox potential were correlated with sediment grain size. Canonical correspondence analysis (CCA) indicated that Uca paradussumieri was negatively correlated with salinity and redox potential. Sand dwelling species, Uca perplexa and Uca annulipes, were highly dependent on the abundance of 250 μm and 150 μm grain size particles in the sediment. Canonical Discriminative Analysis (CDA) indicated that variation in sediment grain size best explained where each crab species was most abundant. Moreover, U. paradussumieri commonly occupies muddy substrates of low shore, while U. forcipata lives under the shade of mangrove trees. U. annulipes and U. perplexa with the high number of spoon tipped setae on their second maxiliped are specialized to feed on the sandy sediments. U. rosea and U. triangularis are more common on muddy sediment with high sediment density. In conclusion, sediment grain size that influences most sediment properties acts as a main factor responsible for sediment heterogeneity. In this paper, the correlation between fiddler crab species and environmental parameters, as well as the interaction between sediment characteristics, was explained in order to define the important environmental factors in fiddler crab distributions. PMID

  13. Status of LHC crab activity simulations and beam studies

    SciTech Connect

    Calaga,R.; Assman, R.; Barranco, J.; Barranco, J.; Calaga, R.; Caspers, F.; Ciapala, E.; De-Maria, R.; Koutchouk, J. P.; Linnecar, T.; Metral, E.; Morita, A.; Solyak, N.; Sun, Y.; Tomas, R.; Tuckmantel, J.; Weiler, T.; Zimmermann, F.

    2009-05-04

    The LHC crab cavity program is advancing rapidly towards a first prototype which is anticipated to be tested during the early stages of the LHC phase I upgrade and commissioning. The general project status and some aspects related to crab optics, collimation, aperture constraints, impedances, noise effects. beam transparency and machine protection critical for a safe and robust operation of LHC beams with crab cavities are addressed here.

  14. A 150-million-year-old crab larva and its implications for the early rise of brachyuran crabs.

    PubMed

    Haug, Joachim T; Martin, Joel W; Haug, Carolin

    2015-03-09

    True crabs (Brachyura) are the most successful group of decapod crustaceans. This success is most likely coupled to their life history, including two specialised larval forms, zoea and megalopa. The group is comparably young, starting to diversify only about 100 million years ago (mya), with a dramatic increase in species richness beginning approximately 50 mya. Early evolution of crabs is still very incompletely known. Here, we report a fossil crab larva, 150 mya, documented with up-to-date imaging techniques. It is only the second find of any fossil crab larva, but the first complete one, the first megalopa, and the oldest one (other fossil ca. 110 mya). Despite its age, the new fossil possesses a very modern morphology, being indistinguishable from many extant crab larvae. Hence, modern morphologies must have been present significantly earlier than formerly anticipated. We briefly discuss the impact of this find on our understanding of early crab evolution.

  15. Crab Crossing Schemes and Studies for Electron Ion Collider

    SciTech Connect

    S. Ahmed, Y. Derbenev, V. Morozov, A. Castilla, G.A. Krafft, B. Yunn, Y. Zhang, J.R. Delayen

    2011-09-01

    This report shows our progress in crab crossing consideration for future electron-ion collider envisioned at JLab. In this design phase, we are evaluating two crabbing schemes viz., the deflecting and dispersive. The mathematical formulations and lattice design for these schemes are discussed in this paper. Numerical simulations involving particle tracking through a realistic deflecting RF cavity and optics illustrate the desired crab tilt of 25 mrad for 1.35 MV. Evolution of beam propagation are shown which provides the physical insight of the crabbing phenomenon.

  16. Bacterial septicaemia in prerecruit edible crabs, Cancer pagurus L.

    PubMed

    Smith, A L; Whitten, M M A; Hirschle, L; Pope, E C; Wootton, E C; Vogan, C L; Rowley, A F

    2014-08-01

    Juvenile edible crabs, Cancer pagurus L., were surveyed from Mumbles Head and Oxwich Bay in South Wales, UK, and the number of heterotrophic bacteria and vibrios in the hemolymph was determined. The percentage of crabs with hemolymph containing bacteria was variable over the survey with higher numbers of animals affected in summer than in winter. Post-moult crabs contained significantly higher numbers of heterotrophic bacteria in the hemolymph than pre- and intermoult animals. Crabs with cuticular damage to the gills also had significantly higher numbers of bacteria in the hemolymph. Crabs were found to have a high prevalence of infection by the dinoflagellate, Hematodinium. Such animals had significantly fewer bacteria in the blood in comparison with Hematodinium-free animals. Of the 463 crabs surveyed, only 3 individuals had hemolymph containing 2000 + CFU mL(-1). Based on 16S rRNA gene sequences, two of these crabs contained a Vibrio pectenicida-like isolate, while the other had a mixed assemblage of vibrios. Although 59% of the crabs surveyed had culturable bacteria in the hemolymph, the majority only had small numbers (<2000 CFU mL(-1) ), suggesting that such infections may be of limited importance to the sustainability of the crab fishery in this region.

  17. IgE sensitization in snow crab-processing workers.

    PubMed

    Cartier, A; Malo, J L; Ghezzo, H; McCants, M; Lehrer, S B

    1986-08-01

    Occupational asthma is a highly prevalent disease among snow crab-processing workers, but its immunologic mechanism has not been identified. Prick skin tests with snow crab-meat extract, commercial extracts from other crab genera, and snow crab cooking water collected in 1984 were performed on 119 workers. Crab-specific IgE was assessed by RAST in sera from 115 workers with meat and water extracts. Both skin and RAST tests were performed in 58 individuals. Diagnosis of occupational asthma had previously been confirmed in 54 individuals. A highly significant relationship was demonstrated between the presence of immediate skin reactivity or increased serum levels of specific IgE to crab extracts and the occurrence of occupational asthma. There was good agreement between the results of skin and RAST tests with extracts of either meat or snow crab cooking water. Cooking water and snow crab-meat extracts were more sensitive than commercial preparations. Water extract was more potent and more sensitive than meat extract. We conclude that there is evidence that occupational asthma in snow crab-processing workers is mediated through an IgE mechanism.

  18. VERITAS observations of the Crab pulsar

    NASA Astrophysics Data System (ADS)

    Zitzer, Benjamin; VERITAS Collaboration

    2012-12-01

    The Crab pulsar has been widely studied across the electromagnetic spectrum from radio to gamma-ray energies. The exact nature of the emission processes taking place in the pulsar is a matter of broad debate. Above a few GeV the energy spectrum turns over suddenly. The shape of this cutoff can provide unique insight in to the particle acceleration processes taking place in the pulsar magnetosphere. Here we discuss the detection of pulsed gamma-rays from the Crab Pulsar above 100 GeV with the VERITAS telescopes in the context of measurements made with the Fermi space telescope below 10 GeV. Limits on the level of flux enhancement of emission correlated with giant radio pulses and dispersion due to Lorentz invariance violation effects will also be presented.

  19. Effect of a Klamath algae product ("AFA-B12") on blood levels of vitamin B12 and homocysteine in vegan subjects: a pilot study.

    PubMed

    Baroni, Luciana; Scoglio, Stefano; Benedetti, Serena; Bonetto, Chiara; Pagliarani, Silvia; Benedetti, Yanina; Rocchi, Marco; Canestrari, Franco

    2009-03-01

    Vitamin B12 is a critical nutrient that is often inadequate in a plant-based (vegan) diet, thus the inclusion of a reliable vitamin B12 source in a vegan diet is recommended as essential. Unfortunately, many natural sources of vitamin B12 have been proven to contain biologically inactive vitamin B12 analogues, inadequate for human supplementation. The aim of this non-randomized open trial was to determine whether supplementation with a natural Klamath algae-based product ("AFA-B12", Aphanizomenon flos-aquae algae plus a proprietary mix of enzymes) could favorably affect the vitamin B12 status of a group of 15 vegan subjects. By assessing blood concentration of vitamin B12, folate, and more importantly homocysteine (Hcy, a reliable marker in vegans of their B12 absorption), the vitamin B12 status of the participants at the end of the 3-month intervention period, while receiving the Klamath-algae supplement (T2), was compared with their vitamin B12 status at the end of the 3-month control period (T1), when they were not receiving any supplement, having stopped taking their usual vitamin B12 supplement at the beginning of the study (T0). Compared to the control period, in the intervention period participants improved their vitamin B12 status, significantly reducing Hcy blood concentration (p=0.003). In conclusion, the Klamath algae product AFA-B12 appears to be, in a preliminary study, an adequate and reliable source of vitamin B12 in humans.

  20. Prevalence, characterization and sources of Listeria monocytogenes in blue crab (Callinectus sapidus) meat and blue crab processing plants.

    PubMed

    Pagadala, Sivaranjani; Parveen, Salina; Rippen, Thomas; Luchansky, John B; Call, Jeffrey E; Tamplin, Mark L; Porto-Fett, Anna C S

    2012-09-01

    Seven blue crab processing plants were sampled to determine the prevalence and sources of Listeria spp. and Listeria monocytogenes for two years (2006-2007). A total of 488 raw crabs, 624 cooked crab meat (crab meat) and 624 environmental samples were tested by standard methods. Presumptive Listeria spp. were isolated from 19.5% of raw crabs, 10.8% of crab meat, and 69.5% of environmental samples. L. monocytogenes was isolated from 4.5% of raw crabs, 0.2% of crab meat, and 2.1% of environmental samples. Ninety-seven percent of the isolates were resistant to at least one of the ten antibiotics tested. Eight different serotypes were found among 76 L. monocytogenes isolates tested with the most common being 4b, 1/2b and 1/2a. Automated EcoRI ribotyping differentiated 11 ribotypes among the 106 L. monocytogenes isolates. Based on ribotyping analysis, the distribution of the ribotypes in each processing plant had a unique contamination pattern. A total of 92 ApaI and 88 AscI pulsotypes among the 106 L. monocytogenes isolates were found and distinct pulsotypes were observed in raw crab, crab meat and environmental samples. Ribotypes and serotypes recovered from crab processing plants included subtypes that have been associated with listeriosis cases in other food outbreaks. Our findings suggest that molecular methods may provide critical information about sources of L. monocytogenes in crab processing plants and will augment efforts to improve food safety control strategies such as targeting specific sources of contamination and use of aggressive detergents prior to sanitizing.

  1. Effects and mechanism of action of naphthalene, a petroleum-derived polycyclic aromatic hydrocarbon, on black pigment dispersion in the salt marsh fiddler crab, UCA pugilator

    SciTech Connect

    Staub, G.C.

    1983-01-01

    At a concentration of approximately 8 ppm, naphthalene inhibited circadian black pigment dispersion in the integumentary chromatophores of the fiddler crab no matter what the initial state of the black pigment. The inhibition was concentration dependent. Naphthalene was not toxic to fiddler crabs under these conditions at any concentration up to 16.69 ppm. No chemically induced phase shift in the circadian rhythm of naphthalene exposed crabs occurs. In addition there is no difference in the mean black chromatophore index at midnight between control and naphthalene exposed crabs, indicating that the release of black pigment concentrating hormone (BPCH) is not being influenced by naphthalene. The only possibility remaining is that naphthalene must interfere with some aspect of the control of BPDH release by NE. Exposure to naphthalene does not inhibit black pigment dispersion when crabs are placed on a black background or kept on a black background throughout the experiment. This argues against naphthalene acting to inhibit the synthesis of NE, or to promote its metabolism, since NE is involved in adaptation to a black background. Naphthalene, therefore, must act to prevent the release of BPDH by interfering with some aspect of the presynaptic control of BPDH release by NE.

  2. Status of the ILC Crab Cavity Development

    SciTech Connect

    Burt, G.; Dexter, A.; Beard, C.; Goudket, P.; McIntosh, P.; Bellantoni, L.; Grimm, T.; Li, Z.; Xiao, L.; /SLAC

    2011-10-20

    The International Linear Collider (ILC) will require two dipole cavities to 'crab' the electron and positron bunches prior to their collision. It is proposed to use two 9 cell SCRF dipole cavities operating at a frequency of 3.9 GHz, with a transverse gradient of 3.8MV/m in order to provide the required transverse kick. Extensive numerical modelling of this cavity and its couplers has been performed. Aluminium prototypes have been manufactured and tested to measure the RF properties of the cavity and couplers. In addition single cell niobium prototypes have been manufactured and tested in a vertical cryostat. The International Collider (ILC) [1] collides bunches of electrons and positrons at a crossing angle of 14 mrad. The angle between these bunches causes a loss in luminosity due to geometric effects [2]. The luminosity lost from this geometric effect can be recovered by rotating the bunches into alignment prior to collision. One possible method of rotating the bunches is to use a crab cavity [3]. A crab cavity is a transverse defecting cavity, where the phase of the cavity is such that the head and tail of the bunch receive equal and opposite kicks. As the bunches are only 500 nm wide in the horizontal plane, the cavity phase must be strictly controlled to avoid the bunch centre being deflected too much. In order to keep the phase stability within the required limits it is required that the cavity be superconducting to avoid thermal effects in both the cavity and its RF source. At the location of the crab cavity in the ILC there is only 23 cm separation between the centre of the cavity and the extraction line, hence the cavity must be small enough to fit in this space. This, along with the difficulty of making high frequency SRF components, set the frequency of the cavity to 3.9 GHz.

  3. Compact Superconducting Crabbing and Deflecting Cavities

    SciTech Connect

    De Silva, Payagalage Subashini Uddika

    2012-09-01

    Recently, new geometries for superconducting crabbing and deflecting cavities have been developed that have significantly improved properties over those the standard TM{sub 110} cavities. They are smaller, have low surface fields, high shunt impedance and, more importantly for some of them, no lower-order-mode with a well-separated fundamental mode. This talk will present the status of the development of these cavities.

  4. Peculair Abundances in the Crab Nebula's Filaments

    NASA Astrophysics Data System (ADS)

    Fesen, Robert A.

    Investigations into the elemental abundances of supernova remnants can provide invaluable information concerning the properties of the progenitor star as well as details of stellar nucleosynthesis. In this regard, the Crab Nebula is especially useful, it being the youngest supernova remnant observable with IUE. Despite being fairly heavily reddened, UV emission-lines from its filaments have been successfully obtained many times early in the history of IUE. These UV spectra provided important and unique data for determining elemental composition of the filamentary ejecta, especially for C, N, and O. Analysis of these data by Davidson et al (1982) indicated nearly solar C/O and N/O ratios despite the large general enrichment of helium in the remnant. Although not realized at the time, there is considerable recent evidence which indicates that significant abundance variations do exist among the filaments. The strongest anomalies in composition are puzzlingly confined to a few relatively bright northern filaments which exhibit nearly solar He abundance yet show possibly large Ni enrichment. If we hope to understand the elemental composition of remnants in general and the Crab Nebula in particular, we then need to determine the composition of these peculiar filaments and to what extent they differ from the rest of the remnant. Towards that goal, we therefore propose to obtain IUE low dispersion SWP spectra on the brightest of these peculiar filaments where we have already obtained matching optical data. Analysis will follow that of Davidson el al but with much more detailed photoionization models for the Crab already developed by us. These data should help determine the true range of abundances present in the Crab's filamentary ejecta.

  5. CMS distributed data analysis with CRAB3

    DOE PAGES

    Mascheroni, M.; Balcas, J.; Belforte, S.; Bockelman, B. P.; Hernandez, J. M.; Ciangottini, D.; Konstantinov, P. B.; Silva, J. M. D.; Ali, M. A. B. M.; Melo, A. M.; et al

    2015-12-23

    The CMS Remote Analysis Builder (CRAB) is a distributed workflow management tool which facilitates analysis tasks by isolating users from the technical details of the Grid infrastructure. Throughout LHC Run 1, CRAB has been successfully employed by an average of 350 distinct users each week executing about 200,000 jobs per day.CRAB has been significantly upgraded in order to face the new challenges posed by LHC Run 2. Components of the new system include 1) a lightweight client, 2) a central primary server which communicates with the clients through a REST interface, 3) secondary servers which manage user analysis tasks andmore » submit jobs to the CMS resource provisioning system, and 4) a central service to asynchronously move user data from temporary storage in the execution site to the desired storage location. Furthermore, the new system improves the robustness, scalability and sustainability of the service.Here we provide an overview of the new system, operation, and user support, report on its current status, and identify lessons learned from the commissioning phase and production roll-out.« less

  6. CMS distributed data analysis with CRAB3

    SciTech Connect

    Mascheroni, M.; Balcas, J.; Belforte, S.; Bockelman, B. P.; Hernandez, J. M.; Ciangottini, D.; Konstantinov, P. B.; Silva, J. M. D.; Ali, M. A. B. M.; Melo, A. M.; Riahi, H.; Tanasijczuk, A. J.; Yusli, M. N. B.; Wolf, M.; Woodard, A. E.; Vaandering, E.

    2015-12-23

    The CMS Remote Analysis Builder (CRAB) is a distributed workflow management tool which facilitates analysis tasks by isolating users from the technical details of the Grid infrastructure. Throughout LHC Run 1, CRAB has been successfully employed by an average of 350 distinct users each week executing about 200,000 jobs per day.CRAB has been significantly upgraded in order to face the new challenges posed by LHC Run 2. Components of the new system include 1) a lightweight client, 2) a central primary server which communicates with the clients through a REST interface, 3) secondary servers which manage user analysis tasks and submit jobs to the CMS resource provisioning system, and 4) a central service to asynchronously move user data from temporary storage in the execution site to the desired storage location. Furthermore, the new system improves the robustness, scalability and sustainability of the service.Here we provide an overview of the new system, operation, and user support, report on its current status, and identify lessons learned from the commissioning phase and production roll-out.

  7. CRAB: Distributed analysis tool for CMS

    NASA Astrophysics Data System (ADS)

    Sala, Leonardo; CMS Collaboration

    2012-12-01

    CMS has a distributed computing model, based on a hierarchy of tiered regional computing centers and adopts a data driven model for the end user analysis. This model foresees that jobs are submitted to the analysis resources where data are hosted. The increasing complexity of the whole computing infrastructure makes the simple analysis work flow more and more complicated for the end user. CMS has developed and deployed a dedicated tool named CRAB (CMS Remote Analysis Builder) in order to guarantee the physicists an efficient access to the distributed data whilst hiding the underlying complexity. This tool is used by CMS to enable the running of physics analysis jobs in a transparent manner over data distributed across sites. It factorizes out the interaction with the underlying batch farms, grid infrastructure and CMS data management tools, allowing the user to deal only with a simple and intuitive interface. We present the CRAB architecture, as well as the current status and lessons learnt in deploying this tool for use by the CMS collaboration. We also present the future development of the CRAB system.

  8. CMS distributed data analysis with CRAB3

    NASA Astrophysics Data System (ADS)

    Mascheroni, M.; Balcas, J.; Belforte, S.; Bockelman, B. P.; Hernandez, J. M.; Ciangottini, D.; Konstantinov, P. B.; Silva, J. M. D.; Ali, M. A. B. M.; Melo, A. M.; Riahi, H.; Tanasijczuk, A. J.; Yusli, M. N. B.; Wolf, M.; Woodard, A. E.; Vaandering, E.

    2015-12-01

    The CMS Remote Analysis Builder (CRAB) is a distributed workflow management tool which facilitates analysis tasks by isolating users from the technical details of the Grid infrastructure. Throughout LHC Run 1, CRAB has been successfully employed by an average of 350 distinct users each week executing about 200,000 jobs per day. CRAB has been significantly upgraded in order to face the new challenges posed by LHC Run 2. Components of the new system include 1) a lightweight client, 2) a central primary server which communicates with the clients through a REST interface, 3) secondary servers which manage user analysis tasks and submit jobs to the CMS resource provisioning system, and 4) a central service to asynchronously move user data from temporary storage in the execution site to the desired storage location. The new system improves the robustness, scalability and sustainability of the service. Here we provide an overview of the new system, operation, and user support, report on its current status, and identify lessons learned from the commissioning phase and production roll-out.

  9. The Porcelain Crab Transcriptome and PCAD, the Porcelain Crab Microarray and Sequence Database

    SciTech Connect

    Tagmount, Abderrahmane; Wang, Mei; Lindquist, Erika; Tanaka, Yoshihiro; Teranishi, Kristen S.; Sunagawa, Shinichi; Wong, Mike; Stillman, Jonathon H.

    2010-01-27

    Background: With the emergence of a completed genome sequence of the freshwater crustacean Daphnia pulex, construction of genomic-scale sequence databases for additional crustacean sequences are important for comparative genomics and annotation. Porcelain crabs, genus Petrolisthes, have been powerful crustacean models for environmental and evolutionary physiology with respect to thermal adaptation and understanding responses of marine organisms to climate change. Here, we present a large-scale EST sequencing and cDNA microarray database project for the porcelain crab Petrolisthes cinctipes. Methodology/Principal Findings: A set of ~;;30K unique sequences (UniSeqs) representing ~;;19K clusters were generated from ~;;98K high quality ESTs from a set of tissue specific non-normalized and mixed-tissue normalized cDNA libraries from the porcelain crab Petrolisthes cinctipes. Homology for each UniSeq was assessed using BLAST, InterProScan, GO and KEGG database searches. Approximately 66percent of the UniSeqs had homology in at least one of the databases. All EST and UniSeq sequences along with annotation results and coordinated cDNA microarray datasets have been made publicly accessible at the Porcelain Crab Array Database (PCAD), a feature-enriched version of the Stanford and Longhorn Array Databases.Conclusions/Significance: The EST project presented here represents the third largest sequencing effort for any crustacean, and the largest effort for any crab species. Our assembly and clustering results suggest that our porcelain crab EST data set is equally diverse to the much larger EST set generated in the Daphnia pulex genome sequencing project, and thus will be an important resource to the Daphnia research community. Our homology results support the pancrustacea hypothesis and suggest that Malacostraca may be ancestral to Branchiopoda and Hexapoda. Our results also suggest that our cDNA microarrays cover as much of the transcriptome as can reasonably be captured in

  10. Comparative analysis of the proximate and elemental composition of the blue crab Callinectes sapidus, the warty crab Eriphia verrucosa, and the edible crab Cancer pagurus.

    PubMed

    Zotti, Maurizio; Coco, Laura Del; Pascali, Sandra Angelica De; Migoni, Danilo; Vizzini, Salvatrice; Mancinelli, Giorgio; Fanizzi, Francesco Paolo

    2016-02-01

    The proximate composition and element contents of claw muscle tissue of Atlantic blue crabs (Callinectes sapidus) were compared with the native warty crab (Eriphia verrucosa) and the commercially edible crab (Cancer pagurus). The scope of the analysis was to profile the chemical characteristics and nutritive value of the three crab species. Elemental fingerprints showed significant inter-specific differences, whereas non-significant variations in the moisture and ash contents were observed. In the blue crab, protein content was significantly lower than in the other two species, while its carbon content resulted lower than that characterizing only the warty crab. Among micro-elements, Ba, Cr, Cu, Li, Mn, Ni, and Pb showed extremely low concentrations and negligible among-species differences. Significant inter-specific differences were observed for Na, Sr, V, Ba, Cd and Zn; in particular, cadmium and zinc were characterized in the blue crab by concentrations significantly lower than in the other two species. The analysis of the available literature on the three species indicated a general lack of comparable information on their elemental composition. The need to implement extended elemental fingerprinting techniques for shellfish quality assessment is discussed, in view of other complementary profiling methods such as NMR-based metabolomics. PMID:27441254

  11. Comparative analysis of the proximate and elemental composition of the blue crab Callinectes sapidus, the warty crab Eriphia verrucosa, and the edible crab Cancer pagurus.

    PubMed

    Zotti, Maurizio; Coco, Laura Del; Pascali, Sandra Angelica De; Migoni, Danilo; Vizzini, Salvatrice; Mancinelli, Giorgio; Fanizzi, Francesco Paolo

    2016-02-01

    The proximate composition and element contents of claw muscle tissue of Atlantic blue crabs (Callinectes sapidus) were compared with the native warty crab (Eriphia verrucosa) and the commercially edible crab (Cancer pagurus). The scope of the analysis was to profile the chemical characteristics and nutritive value of the three crab species. Elemental fingerprints showed significant inter-specific differences, whereas non-significant variations in the moisture and ash contents were observed. In the blue crab, protein content was significantly lower than in the other two species, while its carbon content resulted lower than that characterizing only the warty crab. Among micro-elements, Ba, Cr, Cu, Li, Mn, Ni, and Pb showed extremely low concentrations and negligible among-species differences. Significant inter-specific differences were observed for Na, Sr, V, Ba, Cd and Zn; in particular, cadmium and zinc were characterized in the blue crab by concentrations significantly lower than in the other two species. The analysis of the available literature on the three species indicated a general lack of comparable information on their elemental composition. The need to implement extended elemental fingerprinting techniques for shellfish quality assessment is discussed, in view of other complementary profiling methods such as NMR-based metabolomics.

  12. Molecular evidence for color discrimination in the Atlantic sand fiddler crab, Uca pugilator

    PubMed Central

    Rajkumar, Premraj; Rollmann, Stephanie M.; Cook, Tiffany A.; Layne, John E.

    2010-01-01

    SUMMARY Fiddler crabs are intertidal brachyuran crabs that belong to the genus Uca. Approximately 97 different species have been identified, and several of these live sympatrically. Many have species-specific body color patterns that may act as signals for intra- and interspecific communication. To understand the behavioral and ecological role of this coloration we must know whether fiddler crabs have the physiological capacity to perceive color cues. Using a molecular approach, we identified the opsin-encoding genes and determined their expression patterns across the eye of the sand fiddler crab, Uca pugilator. We identified three different opsin-encoding genes (UpRh1, UpRh2 and UpRh3). UpRh1 and UpRh2 are highly related and have similarities in their amino acid sequences to other arthropod long- and medium-wavelength-sensitive opsins, whereas UpRh3 is similar to other arthropod UV-sensitive opsins. All three opsins are expressed in each ommatidium, in an opsin-specific pattern. UpRh3 is present only in the R8 photoreceptor cell, whereas UpRh1 and UpRh2 are present in the R1-7 cells, with UpRh1 expression restricted to five cells and UpRh2 expression present in three cells. Thus, one photoreceptor in every ommatidium expresses both UpRh1 and UpRh2, providing another example of sensory receptor coexpression. These results show that U. pugilator has the basic molecular machinery for color perception, perhaps even trichromatic vision. PMID:21113005

  13. Experimental infections of Orchitophrya stellarum (Scuticociliata) in American blue crabs (Callinectes sapidus) and fiddler crabs (Uca minax).

    PubMed

    Miller, Terrence L; Small, Hamish J; Peemoeller, Bhae-Jin; Gibbs, David A; Shields, Jeffrey D

    2013-11-01

    Outbreaks of an unidentified ciliate have occurred on several occasions in blue crabs from Chesapeake Bay held during winter months in flow-through systems. The parasite was initially thought to be Mesanophrys chesapeakensis, but molecular analysis identified it as Orchitophyra stellarum, a facultative parasite of sea stars (Asteroidea). We investigated the host-parasite association of O. stellarum in the blue crab host. Crabs were inoculated with the ciliate, or they were held in bath exposures after experimentally induced autotomy of limbs in order to determine potential mechanisms for infection. Crabs inoculated with the ciliate, or exposed to it after experimental autotomy, rapidly developed fatal infections. Crabs that were not experimentally injured, but were exposed to the ciliate, rarely developed infections; thus, indicating that the parasite requires a wound or break in the cuticle as a portal of entry. For comparative purposes, fiddler crabs, Uca minax, were inoculated with the ciliate in a dose-titration experiment. Low doses of the ciliate (10 per crab) were sometimes able to establish infections, but high intensity infections developed quickly at doses over 500 ciliates per crab. Chemotaxis studies were initiated to determine if the ciliate preferentially selected blue crab serum (BCS) over other nutrient sources. Cultures grown on medium with BCS or fetal bovine serum showed some conditioning in their selection for different media, but the outcome in choice experiments indicated that the ciliate was attracted to BCS and not seawater. Our findings indicate that O. stellarum is a facultative parasite of blue crabs. It can cause infections in exposed crabs at 10-15°C, but it requires a portal of entry for successful host invasion, and it may find injured hosts using chemotaxis.

  14. 50 CFR 680.21 - Crab harvesting cooperatives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Person ID of each member of the crab harvesting cooperative. (iii) Additional documentation. For the... transfer of crab harvesting cooperative individual fishing quota (IFQ) provided that a paper or electronic... required additional documentation is attached. (2) Certification of transferor—(i) Non-electronic...

  15. 50 CFR 680.21 - Crab harvesting cooperatives.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Person ID of each member of the crab harvesting cooperative. (iii) Additional documentation. For the... transfer of crab harvesting cooperative individual fishing quota (IFQ) provided that a paper or electronic... required additional documentation is attached. (2) Certification of transferor—(i) Non-electronic...

  16. 50 CFR 680.21 - Crab harvesting cooperatives.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Person ID of each member of the crab harvesting cooperative. (iii) Additional documentation. For the... transfer of crab harvesting cooperative individual fishing quota (IFQ) provided that a paper or electronic... required additional documentation is attached. (2) Certification of transferor—(i) Non-electronic...

  17. 50 CFR 680.21 - Crab harvesting cooperatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Person ID of each member of the crab harvesting cooperative. (iii) Additional documentation. For the... transfer of crab harvesting cooperative individual fishing quota (IFQ) provided that a paper or electronic... required additional documentation is attached. (2) Certification of transferor—(i) Non-electronic...

  18. 50 CFR 680.21 - Crab harvesting cooperatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Person ID of each member of the crab harvesting cooperative. (iii) Additional documentation. For the... transfer of crab harvesting cooperative individual fishing quota (IFQ) provided that a paper or electronic... required additional documentation is attached. (2) Certification of transferor—(i) Non-electronic...

  19. Porcelain crabs from Brazil (Crustacea: Decapoda: Anomura: Porcellanidae).

    PubMed

    Ferreira, Luciane Augusto De Azevedo; De Melo, Gustavo Augusto Schmidt

    2016-01-01

    Twenty species of porcelain crabs are reported on the basis of material collected from Brazilian coasts. Considering the lack of systematic studies comprehending the Brazilian porcellanids, the present work presents a review of the regional species based on the current taxonomic information. New records, information about variation between specimens and a taxonomic discussion are given for porcellanid crabs from Brazil. PMID:27394448

  20. 50 CFR Table 4 to Part 680 - Crab Process Codes

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Process Codes 4 Table 4 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION..., Table 4 Table 4 to Part 680—Crab Process Codes Process code Description 0 Other (specify). 1 Fresh....

  1. 50 CFR Table 4 to Part 680 - Crab Process Codes

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Process Codes 4 Table 4 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION..., Table 4 Table 4 to Part 680—Crab Process Codes Process code Description 0 Other (specify). 1 Fresh....

  2. 50 CFR Table 4 to Part 680 - Crab Process Codes

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab Process Codes 4 Table 4 to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION..., Table 4 Table 4 to Part 680—Crab Process Codes Process code Description 0 Other (specify). 1 Fresh....

  3. A developmental model for predicting handedness frequencies in crabs

    NASA Astrophysics Data System (ADS)

    Ladle, Richard J.; Todd, Peter A.

    2006-11-01

    Brachyuran crabs develop handedness in at least two different ways. Some crabs, such as Cancer productus, become heterochelous through use-induced differences in claw growth. Other crab species, for instance Carcinus maenas, appear to have a genetic predisposition towards right handedness. In this latter case, however, handedness reversal may take place following autotomy of the major claw. Thus, in C. maenas, and other species with this developmental strategy, younger cohorts are strongly biased towards right-handed individuals and the frequency of left-handedness increases with each subsequent moult. In the absence of differential mortality the ratio of left-handed to right-handed crabs in a given population should be predictable if the frequencies of right and left claw loss are known for different stages in the life history. Here, we develop a simple mathematical model for predicting handedness in crabs under the Carcinus-model of claw ontogeny and apply it to two species with very different ecologies and life histories; the green crab ( Carcinus maenas (L.)) and the Trinidadian mountain crab ( Eudaniela garmani (Rathburn)). The predicted and observed handedness frequencies were in complete concordance for the early intermoults of both species but significantly deviated in mature C. maenas where left-handed individuals were under-represented in the population. These results are discussed in the context of the evolution and functional significance of claw autotomy and handedness in crabs.

  4. Crabbed Waist Collisions in DAFNE and Super-B Design

    SciTech Connect

    Raimondi, P.; Alesini, D.; Biagini, M.E.; Biscari, C.; Boni, R.; Boscolo, M.; Bossi, F.; Buonomo, B.; Clozza, A.; Delle Monache, G.O.; Demma, T.; Di Pasquale, E.; Di Pirro, G.; Drago, A.; Gallo, A.; Ghigo, A.; Guiducci, S.; Ligi, C.; Marcellini, F.; Mazzitelli, Giovanni; Milardi, C.; /Frascati /Orsay, LAL /CERN /Rome III U. /Rome U. /Novosibirsk, IYF /KEK, Tsukuba /INFN, Pisa /INFN, Cosenza /SLAC /Frascati

    2011-11-02

    The new idea of increasing the luminosity of a collider with crab waist collisions and first experimental results from the DA{Phi}NE {Phi}-Factory at LNF, Frascati, using this concept are presented. Consequences for the design of future factories will be discussed. An outlook to the performance reach with crab waist collisions is given, with emphasis on future B Factories.

  5. The competitive and predatory impacts of the nonindigenous crab Carcinus maenas (L.) on early benthic phase Dungeness crab Cancer magister Dana.

    PubMed

    McDonald, P S.; Jensen, G C.; Armstrong, D A.

    2001-03-30

    We evaluate the potential competitive and predatory impacts of nonindigenous European green crab Carcinus maenas on native Dungeness crab Cancer magister in the northeast Pacific. The coastal estuaries of Washington State, USA, provide appropriate habitat for recently introduced green crab, yet these areas are important nursery grounds for Dungeness crab and contribute greatly to the coastal crab fishery. Juvenile Dungeness crabs are dependent on limited intertidal epibenthic shell for refuge habitat during early benthic life and experience increased mortality on open sand and mud as a result of predation by fish and birds. Early juveniles throughout the subtidal are similarly at risk due to predation by fish and especially adult conspecifics. Laboratory experiments and infrared video observations revealed that juvenile green crab displace Dungeness crab of equal size from shelters during one-on-one competition. Green crab also consistently win nocturnal foraging trials in which the species compete for fresh, damaged clams. Field and laboratory enclosure experiments show that juvenile Dungeness crab emigrate from oyster shell habitat as a result of competition and predation by adult green crab. Depending on the extent to which the two species overlap, interactions with the dominant nonindigenous species could have a negative influence on juvenile Dungeness crab survival and could conceivably impact recruitment to the fishery. However, current evidence indicates that the distribution of green crab in Washington State is far removed from nursery areas of Dungeness crab. PMID:11239624

  6. Mitigating by-catch of diamondback terrapins in crab pots

    USGS Publications Warehouse

    Hart, Kristen M.; Crowder, Larry B.

    2011-01-01

    Chronic by-catch of diamondback terrapins (Malaclemys terrapin) in blue crab (Callinectes sapidus) pots is a concern for terrapin conservation along the United States Atlantic and Gulf of Mexico coasts. Despite the availability of by-catch reduction devices (BRDs) for crab pots, adoption of BRDs has not been mandated and by-catch of terrapins continues. We conducted experimental fishing studies in North Carolina's year-round blue crab fishery from 2000 to 2004 to evaluate the ability of various BRDs to reduce terrapin by-catch without a concomitant reduction in the catch of blue crabs. In 4,822 crab pot days fished, we recorded only 21 terrapin captures. Estimated capture rates were 0.003 terrapins/pot per day in hard crab experimental fishing and 0.008 terrapins/pot per day in peeler experimental fishing. All terrapin captures occurred from April to mid-May within 321.4 m of the shoreline. Longer soak times produced more dead terrapins, with 4 live and 4 dead during hard crab experimental fishing and 11 live and 2 dead during peeler experimental fishing. The 4.0-cm BRDs in fall and 4.5-cm and 5.0-cm BRDs in spring reduced the catch of legal-sized male hard crabs by 26.6%, 21.2%, and 5.7%, respectively. Only the 5.0-cm BRDs did not significantly affect the catch of legal-sized hard male crabs. However, BRDs had no measurable effect on catch of target crabs in the peeler crab fishery. Our results identify 3 complementary and economically feasible tools for blue crab fishery managers to exclude terrapins from commercially fished crab pots in North Carolina: 1) gear modifications (e.g., BRDs); 2) distance-to-shore restrictions; and 3) time-of-year regulations. These measures combined could provide a reduction in terrapin by-catch of up to 95% without a significant reduction in target crab catch.

  7. SMALL ANGLE CRAB COMPENSATION FOR LHC IR UPGRADE

    SciTech Connect

    CALAGA,R.; DORDA, U.; OHMI, D.; OIDE, K.; TOMAS, R.; ZIMMERMANN, F.

    2007-06-25

    A small angle (< 1 mrad) crab scheme is an attractive option for the LHC luminosity upgrade to recover the geometric luminosity loss from the finite crossing angle [I]. The luminosity loss increases steeply to unacceptable levels as the IP beta function is reduced below its nominal value (see Fig. 1 in Ref. [2]). The crab compensation in the LHC can be accomplished using only two sets of deflecting RF cavities, placed in collision-free straight sections of the LHC to nullify the effective crossing angles at IPI & IP5. We also explore a 400 MHz superconducting cavity design and discuss the pertinent RF challenges. We present IR optics configurations with low-angle crab crossing, study the beam-beam performance and proton-beam emittance growth in the presence of crab compensation, lattice errors, and crab RF noise sources.

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

    ERIC Educational Resources Information Center

    Hogarth, P. J.

    1983-01-01

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

  9. 50 CFR 648.263 - Red crab possession and landing restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Red crab possession and landing... Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.263 Red crab possession and landing restrictions. (a) Vessels issued limited access red crab permits—(1) Possession and landing restrictions. (i)...

  10. 75 FR 32360 - Proposed Information Collection; Comment Request; Alaska Crab Report Forms

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... Crab Report Forms AGENCY: National Oceanic and Atmospheric Administration (NOAA), Department of.... 1801 et seq.) The FMP for Bering Sea and Aleutian Islands (BSAI) Crab includes the Crab Rationalization (CR) Program, a limited access system that allocates BSAI Management Area Crab resources...

  11. 50 CFR Table 2b to Part 679 - Species Codes: FMP Prohibited Species and CR Crab

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CR Crab 2b Table 2b to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... CR Crab Species Description Code CR Crab Groundfish PSC CRAB Box Lopholithodes mandtii 900 ✓ Dungeness Cancer magister 910 ✓ King, blue Paralithodes platypus 922 ✓ ✓ King, golden (brown)...

  12. Accumulation of six metals in the mangrove crab Ucides cordatus (Crustacea: Ucididae) and its food source, the red mangrove Rhizophora mangle (Angiosperma: Rhizophoraceae).

    PubMed

    Pinheiro, Marcelo Antonio Amaro; Silva, Pablo Pena Gandara E; Duarte, Luis Felipe de Almeida; Almeida, Alaor Aparecido; Zanotto, Flavia Pinheiro

    2012-07-01

    The crab Ucides cordatus and the red mangrove Rhizophora mangle are endemic mangrove species and potential bio-accumulators of metals. This study quantified the accumulation of six metals (Cd, Cr, Cu, Hg, Mn and Pb) in different organs (claw muscle, hepatopancreas and gills) of U. cordatus, as well as in different maturation stages of the leaves (buds, green mature, and pre-abscission senescent) of R. mangle. Samples were collected from mangrove areas in Cubatão, state of São Paulo, a heavily polluted region in Brazil. Data for metal contents in leaves were evaluated by one-way ANOVA; while for crabs a factorial ANOVA was used to investigate the effect of different tissues, animal size and the interactions between them. Means were compared by Tukey test at five percent, and the association between the metal concentrations in each crab organ, depending on the size, was evaluated by Pearson's linear correlation coefficient (r). Concentrations of Pb and Hg were undetectable for the different leaf stages and crab tissues, while Cd concentrations were undetectable in the leaf stages. In general, the highest accumulation of metals in R. mangle leaves occurred in pre-abscission senescent and green mature leaves, except for Cu, which was found in the highest concentrations in buds and green mature leaves. For the crab, Cd, Cu, Cr and Mn were present in concentrations above the detection limit, with the highest accumulation in the hepatopancreas, followed by the gills. Cu was accumulated mostly in the gills. Patterns of bioaccumulation between the crab and the mangrove tree differed for each metal, probably due to the specific requirements of each organism for essential metals. However, there was a close and direct relationship between metal accumulation in the mangrove trees and in the crabs feeding on them. Tissues of R. mangle leaves and U. cordatus proved effective for monitoring metals, acting as important bioindicators of mangrove areas contaminated by various

  13. Chitin extraction from crab shells by Bacillus bacteria. Biological activities of fermented crab supernatants.

    PubMed

    Hajji, Sawssen; Ghorbel-Bellaaj, Olfa; Younes, Islem; Jellouli, Kemel; Nasri, Moncef

    2015-08-01

    Crab shells waste were fermented using six protease-producing Bacillus species (Bacillus subtilis A26, Bacillus mojavensis A21, Bacillus pumilus A1, Bacillus amyloliquefaciens An6, Bacillus licheniformis NH1 and Bacillus cereus BG1) for the production of chitin and fermented-crab supernatants (FCSs). In medium containing only crab shells, the highest demineralization DM was obtained with B. licheniformis NH1 (83±0.5%) and B. pumilus A1 (80±0.6%), while the highest deproteinization (DP) was achieved with A1 (94±1%) followed by NH1 (90±1.5%) strains. Cultures conducted in medium containing crab shells waste supplemented with 5% (w/v) glucose, were found to remarkably promote demineralization efficiency, and enhance slightly deproteinization rates. FTIR spectra of chitins showed the characteristics bands of α-chitin. FCSs showed varying degrees of antioxidant activities which were in a dose-dependent manner (p<0.01). In fact, FCS produced by B. amyloliquefaciens An6 exhibited the highest DPPH free radical-scavenging activity (92% at 4 mg/ml), while the lowest hydroxyl radical-scavenging activity (60% at 4 mg/ml) was obtained with B. subtilis A26 hydrolysates. However, the highest reducing power (OD700nm=2 at 0.5 mg/ml) was obtained by B.amyloliquefaciens An6 hydrolysates. These results suggest that crab hydrolysates are good sources of natural antioxidants. Further, FCSs were found to exhibit antibacterial activity against Gram-positive and Gram-negative bacteria.

  14. Element Masses in the Crab Nebula

    NASA Astrophysics Data System (ADS)

    Sibley, Adam R.; Katz, Andrea M.; Satterfield, Timothy J.; Vanderveer, Steven J.; MacAlpine, Gordon M.

    2016-10-01

    Using our previously published element abundance or mass-fraction distributions in the Crab Nebula, we derived actual mass distributions and estimates for overall nebular masses of hydrogen, helium, carbon, nitrogen, oxygen and sulfur. As with the previous work, computations were carried out for photoionization models involving constant hydrogen density and also constant nuclear density. In addition, employing new flux measurements for [Ni ii] λ7378, along with combined photoionization models and analytic computations, a nickel abundance distribution was mapped and a nebular stable nickel mass estimate was derived.

  15. Habitat Suitability Index Models: Red king crab

    USGS Publications Warehouse

    Jewett, Stephen C.; Onuf, Christopher P.

    1988-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for evaluating habitat of different life stages of red king crab (Paralithodes camtschatica). A model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) and 1.0 (optimum habitat) in Alaskan coastal waters, especially in the Gulf of Alaska and the southeastern Bering Sea. HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  16. Effects of pesticides on crab cheliped regeneration

    SciTech Connect

    Costlow, J.D. Jr.

    1993-01-01

    The mud crab cheliped regeneration bioassay has proven to be a sensitive and reliable bioassay in studies of the potential sublethal effects of pesticides, including teratogenesis, spontaneous autotomy, and duration of the various stages of development. The assay has also been demonstated to be a useful indication of mortality associated with the impact of these chemicals of anthropogenic origin during the megalopal and early postlarval stages of development. Four pesticides were tested here using the cheliped regeneration bioassay technique. Although carbofuran is approximately 5--6 times more toxic than methomyl, both compounds yield very similar results in terms of sublethal effects.

  17. Switching skeletons: hydrostatic support in molting crabs

    NASA Technical Reports Server (NTRS)

    Taylor, Jennifer R A.; Kier, William M.; Walker, I. D. (Principal Investigator)

    2003-01-01

    Skeletal support systems are essential for support, movement, muscular antagonism, and locomotion. Crustaceans shed their rigid exoskeleton at each molt yet are still capable of forceful movement. We hypothesize that the soft water-inflated body of newly molted crabs may rely on a hydrostatic skeleton, similar to that of worms and polyps. We measured internal hydrostatic pressure and the force exerted during claw adduction and observed a strong correlation between force and hydrostatic pressure, consistent with hydrostatic skeletal support. This alternation between the two basic skeletal types may be widespread among arthropods.

  18. Abundance, Health and Status of Sand Crabs at Ocean Beach, San Francisco: Comparisons From two Summers, 2003 and 2004

    NASA Astrophysics Data System (ADS)

    Conrad-Saydah, A.; MacCormack, D.; Velarde, M.; Masters, D.; Walton, M.

    2004-12-01

    Interns from the California Academy of Sciences in San Francisco monitored Pacific mole crabs, Emerita analoga, commonly known as sand crabs, at Ocean Beach, San Francisco for the second consecutive summer. Comparisons from two data sets revealed trends in crab abundance, size and location. Changes in abundance and location may have been related to water temperature and predation. Dissections of random crabs from all gender classes allowed inspection of parasitism on the crabs. The dissections revealed increased numbers of parasites in larger crabs (especially females with eggs) and in crabs collected later in the summer season. Crab parasitism may be connected to population changes of species predating the sand crabs.

  19. Polychlorinated biphenyls in blue crabs from South Carolina

    SciTech Connect

    Marcus, J.M.; Mathews, T.D.

    1987-11-01

    Blue crabs are important members of the estuarine food web due to their numbers and their multiple roles as scavengers, predators and prey. Because of their omnivorous feeding characteristics, wide distribution an close association with bottom sediments, the potential exists for blue crabs to bioaccumulate pollutants residing in those sediments as has been shown for fiddler crabs. It follows that human health risk upon consumption of such crabs and biomagnification through the food web become primary concerns. During the spring of 1985, commercial crab fishermen in Beaufort County, South Carolina contacted the South Carolina Wildlife and Marine Resources Department (SCWMRD) concerning their perceptions of significantly declining catch rates in the Campbell Creek-Whale Branch area. Using knowledge of previously documented elevated polychlorinated biphenyls (PCB) levels in the sediments of the upper portion of Campbell Creek, the SCWMRD initiated analysis of crab tissue from the area to ascertain the body burdens of PCBs. Initial screening results indicated potentially significant levels of PCBs in blue crabs at which time, SCWMRD contacted the SC Department of Health and Environmental Control (SCDHEC) for more intensive study and definition of the situation. The work reported here was conducted between June and October 1985.

  20. The Crab Nebula: The gift that keeps on giving

    NASA Astrophysics Data System (ADS)

    Hester, J. Jeff

    2001-05-01

    In many ways the Crab Nebula is the object that started off the study of supernova remnants, yet hundreds of years after its discovery it is still poorly understood in many respects. Recently, a number of observational and theoretical results have shed new light on longstanding questions and misconceptions about the Crab. We are taught in graduate school that the Crab is a freely expanding ejecta-dominated remnant, with the slight added complication that it contains a pulsar and synchrotron nebula. This conception of the Crab is incorrect. Instead, when we think of the Crab we should think first of the powerful and dynamic axisymmetric wind from an energetic pulsar as it powers a high pressure synchrotron nebula. That synchrotron nebula is sweeping up and concentrating thermal ejecta into dense, complex Rayleigh-Taylor filaments as it pushes its way out through a large, freely expanding remnant. This larger remnant is all but unseen, but probably carries the bulk of the mass and kinetic energy from the explosion. Every aspect of the visible Crab-from its overall size and shape, to the complex structure of its filaments, to the highly dynamical structure at its heart-is a direct result of the action of the wind from the Crab pulsar. .

  1. Symbiotic crabs maintain coral health by clearing sediments

    NASA Astrophysics Data System (ADS)

    Stewart, Hannah L.; Holbrook, Sally J.; Schmitt, Russell J.; Brooks, Andrew J.

    2006-11-01

    Stony corals are the foundation of coral reef ecosystems and form associations with other reef species. Many of these associations may be ecologically important and play a role in maintaining the health and diversity of reef systems, rendering it critical to understand the influence of symbiotic organisms in mediating responses to perturbation. This study demonstrates the importance of an association with trapeziid crabs in reducing adverse effects of sediments deposited on corals. In a field experiment, mortality rates of two species of branching corals were significantly lowered by the presence of crabs. All outplanted corals with crabs survived whereas 45-80% of corals without crabs died within a month. For surviving corals that lacked crabs, growth was slower and tissue bleaching and sediment load were higher. Laboratory experiments revealed that corals with crabs shed substantially more of the sediments deposited on coral surfaces, but also that crabs were most effective at removing grain sizes that were most damaging to coral tissues. The mechanism underlying this symbiotic relationship has not been recognized previously, and its role in maintaining coral health is likely to become even more critical as reefs worldwide experience increasing sedimentation.

  2. Vitellogenin2: spermatozoon specificity and immunoprotection in mud crabs.

    PubMed

    Yang, Ya'nan; Zheng, Biqi; Bao, Chenchang; Huang, Huiyang; Ye, Haihui

    2016-09-01

    As the precursor of vitellin (Vn), vitellogenin (Vg) has initially been considered as a female-specific protein involved in vitellogenesis, while it was also present in males induced by hormones or organs manipulation. Distinct from vtg1 we previously found in female mud crab Scylla paramamosain, vtg2 was intriguingly detected in male testis under normal physiological conditions in this study. Sequence analysis showed that vtg2 and vtg1 were actually two isoforms of Vg caused by different types of alternative splicing. PCR and in situ hybridization analysis revealed that vtg2 was localized only in the testicular spermatozoa, while Vn was detected in both the spermatozoa of the testis and seminal vesicle. Therefore, we speculated that Vn was initially translated in testicular spermatozoa, then migrated with spermatozoa, and finally stored in the seminal vesicle, where spermatozoa gradually accomplished maturation. We presumed that vtg2/Vn might act as an immune-relevant molecule in the male reproduction system. In the subsequent experiment, the expression of vtg2/Vn in testis was significantly induced in response to lipopolysaccharide (LPS) and lipoteichoic acid (LTA) injection at both transcriptional and translational levels. In the light of the results presented above, we deemed that vtg2/Vn is a novel candidate of immune-relevant molecules involved in immunoprotection during the spermatozoon maturation, and this research helps to open a new avenue for further exploring the role of Vg. PMID:27458256

  3. OBSERVATIONS OF THE CRAB NEBULA'S ASYMMETRICAL DEVELOPMENT

    SciTech Connect

    Loll, A. M.; Desch, S. J.; Scowen, P. A.; Foy, J. P.

    2013-03-10

    We present the first Hubble Space Telescope Wide Field Planetary Camera-2 imaging survey of the entire Crab Nebula, in the filters F502N ([O III] emission), F673N ([S II]), F631N ([O I]), and F547M (continuum). We use our mosaics to characterize the pulsar wind nebula (PWN) and its three-dimensional structure, the ionizational structure in the filaments forming at its periphery, the speed of the shock driven by the PWN into surrounding ejecta (by inferring the cooling rates behind the shock), and the morphology and ionizational structure of the Rayleigh-Taylor (R-T) fingers. We quantify a number of asymmetries between the northwest (NW) and southeast (SE) quadrants of the Crab Nebula. The lack of observed filaments in the NW, and our observations of the spatial extent of [O III] emission lead us to conclude that cooling rates are slower, and therefore the shock speeds are greater, in the NW quadrant of the nebula, compared with the SE. We conclude that R-T fingers are longer, more ionizationally stratified, and apparently more massive in the NW than in the SE, and the R-T instability appears more fully developed in the NW.

  4. Lever-press conditioning in the crab.

    PubMed

    Abramson, C I; Feinman, R D

    1990-08-01

    An operant chamber has been developed for studying lever-press conditioning in the green crab Carcinus maenas. In one series of experiments, animals were presented with a single bar and were reinforced with food for every bar press. Performance increased over time and high rates of responding were observed after 2 days of training. The response rate was always higher than that for a yoked (noncontingent) control group. When the contingencies were switched, the animals adjusted to the new conditions. Discrimination in the lever-press apparatus was demonstrated in a second experiment in which crabs had to choose between two bars, one (S+) caused food to be dispensed while the other (S-) was inactive. Experimental animals pressed the S+ bar at a significantly higher rate than the S- bar. When the contingencies associated with the lever were reversed, animals learned to switch to the correct bar by the second day. It was not necessary to reinforce every response: animals maintained high rates of responding on a schedule where every other response was reinforced. Animals used different methods of pressing the bar; the most common was extension of the claw, predominantly at the meropodite-carpopodite joint. PMID:2255730

  5. Pulsar Radio Emission Mechanisms: The Crab Enigmas

    NASA Astrophysics Data System (ADS)

    Hankins, Timothy

    2012-03-01

    The Crab pulsar, which resulted from a supernova explosion in year 1054 A. D., has been studied intensely over a wide range of wavelengths, yet it continues to reveal new phenomena that challenge explanation. The emission structures in the radio regime are complex and some may be unique among pulsars. The standard models for pulsar geometry and radio emission physics are reviewed briefly. Their predictions are then compared with observations of the Crab pulsar radio emission and the observations are used to critique the theoretical models from an observer's point of view. The models must explain the extremely short and bright nanopulses (0.4 ns duration implying an equivalent brightness temperature of 10^42 K), the wide bandwidths of radio emission (at least 0.02 to 46 GHz), the regular banded nature of the high frequency interpulse emission, the complex polarization structure, and the phases of pulsar rotation where emission occurs. So far no comprehensive model satisfies all of the observational discriminants.

  6. Effects of Underwater Turbine Noise on Crab Larval Metamorphosis.

    PubMed

    Pine, Matthew K; Jeffs, Andrew G; Radford, Craig A

    2016-01-01

    The development of marine tidal turbines has advanced at a rapid rate over the last decade but with little detailed understanding of the potential noise impacts on invertebrates. Previous research has shown that underwater reef noise plays an important role in mediating metamorphosis in many larval crabs and fishes. New research suggests that underwater estuarine noise may also mediate metamorphosis in estuarine crab larvae and that the noise emitted from underwater tidal and sea-based wind turbines may significantly influence larval metamorphosis in estuarine crabs.

  7. Effects of Underwater Turbine Noise on Crab Larval Metamorphosis.

    PubMed

    Pine, Matthew K; Jeffs, Andrew G; Radford, Craig A

    2016-01-01

    The development of marine tidal turbines has advanced at a rapid rate over the last decade but with little detailed understanding of the potential noise impacts on invertebrates. Previous research has shown that underwater reef noise plays an important role in mediating metamorphosis in many larval crabs and fishes. New research suggests that underwater estuarine noise may also mediate metamorphosis in estuarine crab larvae and that the noise emitted from underwater tidal and sea-based wind turbines may significantly influence larval metamorphosis in estuarine crabs. PMID:26611041

  8. Are the pulses of the Crab pulsar modulated?

    NASA Astrophysics Data System (ADS)

    Cadez, A.; Galicic, M.

    1996-02-01

    We present the results of optical Crab pulsar observations which were designed to search for short-time variations in pulsar's light-curve. Hubble Space Telescope (High Speed Photometer) data and photometric data obtained at the Asiago 1.82m telescope using a specially designed stroboscopic chopper have been analysed and compared. We find a very weak common modulation with the period of 60 seconds which is consistent with all data sets. Such periodic variations in Crab pulsar's light-curve might reflect the pertained free precession of the young Crab pulsar.

  9. Comparison of automated BAX polymerase chain reaction and standard culture methods for detection of Listeria monocyogenes in blue crab meat (Callinectus sapidus) and blue crab processing plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compared the BAX Polymerase Chain Reaction method (BAX PCR) with the Standard Culture Method (SCM) for detection of L. monocytogenes in blue crab meat and crab processing plants. The aim of this study was to address this data gap. Raw crabs, finished products and environmental sponge samp...

  10. Evolutionary history of true crabs (Crustacea: Decapoda: Brachyura) and the origin of freshwater crabs.

    PubMed

    Tsang, Ling Ming; Schubart, Christoph D; Ahyong, Shane T; Lai, Joelle C Y; Au, Eugene Y C; Chan, Tin-Yam; Ng, Peter K L; Chu, Ka Hou

    2014-05-01

    Crabs of the infra-order Brachyura are one of the most diverse groups of crustaceans with approximately 7,000 described species in 98 families, occurring in marine, freshwater, and terrestrial habitats. The relationships among the brachyuran families are poorly understood due to the high morphological complexity of the group. Here, we reconstruct the most comprehensive phylogeny of Brachyura to date using sequence data of six nuclear protein-coding genes and two mitochondrial rRNA genes from more than 140 species belonging to 58 families. The gene tree confirms that the "Podotremata," are paraphyletic. Within the monophyletic Eubrachyura, the reciprocal monophyly of the two subsections, Heterotremata and Thoracotremata, is supported. Monophyly of many superfamilies, however, is not recovered, indicating the prevalence of morphological convergence and the need for further taxonomic studies. Freshwater crabs were derived early in the evolution of Eubrachyura and are shown to have at least two independent origins. Bayesian relaxed molecular methods estimate that freshwater crabs separated from their closest marine sister taxa ~135 Ma, that is, after the break up of Pangaea (∼200 Ma) and that a Gondwanan origin of these freshwater representatives is untenable. Most extant families and superfamilies arose during the late Cretaceous and early Tertiary.

  11. The surprising Crab pulsar and its nebula: a review.

    PubMed

    Bühler, R; Blandford, R

    2014-06-01

    The Crab nebula and its pulsar (referred to together as 'the Crab') have historically played a central role in astrophysics. True to this legacy, several unique discoveries have been made recently. The Crab was found to emit gamma-ray pulsations up to energies of 400 GeV, beyond what was previously expected from pulsars. Strong gamma-ray flares, of durations of a few days, were discovered from within the nebula, while the source was previously expected to be stable in flux on these time scales. Here we review these intriguing and suggestive developments. In this context we give an overview of the observational properties of the Crab and our current understanding of pulsars and their nebulae. PMID:24913306

  12. EVOLUTION OF THE CRAB NEBULA IN A LOW ENERGY SUPERNOVA

    SciTech Connect

    Yang, Haifeng; Chevalier, Roger A. E-mail: rac5x@virginia.edu

    2015-06-20

    The nature of the supernova leading to the Crab Nebula has long been controversial because of the low energy that is present in the observed nebula. One possibility is that there is significant energy in extended fast material around the Crab but searches for such material have not led to detections. An electron capture supernova model can plausibly account for the low energy and the observed abundances in the Crab. Here, we examine the evolution of the Crab pulsar wind nebula inside a freely expanding supernova and find that the observed properties are most consistent with a low energy event. Both the velocity and radius of the shell material, and the amount of gas swept up by the pulsar wind point to a low explosion energy (∼10{sup 50} erg). We do not favor a model in which circumstellar interaction powers the supernova luminosity near maximum light because the required mass would limit the freely expanding ejecta.

  13. Crab cavities: Past, present, and future of a challenging device

    SciTech Connect

    Wu, Q.

    2015-05-03

    In two-ring facilities operating with a crossing-angle collision scheme, luminosity can be limited due to an incomplete overlapping of the colliding bunches. Crab cavities then are introduced to restore head-on collisions by providing the destined opposite deflection to the head and tail of the bunch. An increase in luminosity was demonstrated at KEKB with global crab-crossing, while the Large Hardron Collider (LHC) at CERN currently is designing local crab crossing for the Hi-Lumi upgrade. Future colliders may investigate both approaches. In this paper, we review the challenges in the technology, and the implementation of crab cavities, while discussing experience in earlier colliders, ongoing R&D, and proposed implementations for future facilities, such as HiLumi-LHC, CERN’s compact linear collider (CLIC), the international linear collider (ILC), and the electron-ion collider under design at BNL (eRHIC).

  14. The surprising Crab pulsar and its nebula: a review.

    PubMed

    Bühler, R; Blandford, R

    2014-06-01

    The Crab nebula and its pulsar (referred to together as 'the Crab') have historically played a central role in astrophysics. True to this legacy, several unique discoveries have been made recently. The Crab was found to emit gamma-ray pulsations up to energies of 400 GeV, beyond what was previously expected from pulsars. Strong gamma-ray flares, of durations of a few days, were discovered from within the nebula, while the source was previously expected to be stable in flux on these time scales. Here we review these intriguing and suggestive developments. In this context we give an overview of the observational properties of the Crab and our current understanding of pulsars and their nebulae.

  15. Observations of VHE from the Crab Pulsar with VERITAS

    NASA Astrophysics Data System (ADS)

    Archer, Avery; VERITAS Collaboration

    2015-04-01

    The Crab pulsar has been closely studied across the electromagnetic spectrum from radio to TeV energies. Observations in recent years have challenged the favored models for the highest-energy emission. With 107 hours of observation, VERITAS first observed the Crab pulsar above 120 GeV, well above the expected cut-off of a few GeV. Pulsar modeling demonstrates that magnetosphere of the Crab is opaque to VHE photons, narrowing the possible emission regions within the magnetosphere given recent observations. As of fall 2014, the exposure has been increased to over 200 hours. These new VERITAS results help to further constrain the models, providing improved information about the origin of very high energy emission within the pulsar magnetosphere. Presented here are results of ongoing observations and analysis of the Crab pulsar from 100 GeV up to TeV energies with the VERITAS telescopes in the context of modeling viable emission region models.

  16. Evolution of the Crab Nebula in a Low Energy Supernova

    NASA Astrophysics Data System (ADS)

    Yang, Haifeng; Chevalier, Roger A.

    2015-06-01

    The nature of the supernova leading to the Crab Nebula has long been controversial because of the low energy that is present in the observed nebula. One possibility is that there is significant energy in extended fast material around the Crab but searches for such material have not led to detections. An electron capture supernova model can plausibly account for the low energy and the observed abundances in the Crab. Here, we examine the evolution of the Crab pulsar wind nebula inside a freely expanding supernova and find that the observed properties are most consistent with a low energy event. Both the velocity and radius of the shell material, and the amount of gas swept up by the pulsar wind point to a low explosion energy (∼1050 erg). We do not favor a model in which circumstellar interaction powers the supernova luminosity near maximum light because the required mass would limit the freely expanding ejecta.

  17. The Crab Nebula: A Flickering X-ray Candle

    NASA Video Gallery

    The Crab Nebula, created by a supernova seen nearly a thousand years ago, is one of the sky's most famous "star wrecks." For decades, most astronomers have regarded it as the steadiest beacon at X-...

  18. Mate Selection and Mating Behaviour in Spider Crabs

    NASA Astrophysics Data System (ADS)

    Jones, D. R.; Hartnoll, R. G.

    1997-02-01

    Female spider crabs can only mate after the terminal moult, which means that they must either mate whilst soft-shelled after moulting, or subsequently when hard-shelled. There is evidence that some, at least, do both, whereas the majority of crabs mate in only one or other of these states. The mating behaviour, and the means of detecting receptive females, have been studied in a spider crab, Inachus dorsettensis. In this species, mating is predominantly hard-shelled, and receptive females are recognized by their emission of chemical pheromones. The implications of the behaviour patterns for male mating efficiency, sperm competition and female reproductive success are discussed. Mate selection and mating behaviour in other spider crabs are compared with I. dorsettensis. Reasons for similarities and differences are reviewed.

  19. Removal of nickel from aqueous solutions using crab shells.

    PubMed

    Pradhan, Swapna; Shukla, Shyam S; Dorris, Kenneth L

    2005-10-17

    Partially converted crab shell waste, which contains chitosan, was used to remove nickel from water. The chelating ability of chitosan makes it an excellent adsorbent for removing pollutants. Advantages of chitosan in crab shells include availability, low cost, and high biocompatibility. The metal uptake by partially converted crab shell waste was successful and rapid. The sorption occurred primarily within 5 min. The sorption mechanism appears to be quite complicated and cannot be adequately described by either the Langmuir or Freundlich theories. Various anions, including chloride, bromide, fluoride, acetate, sulfate, nitrate, and phosphate, were found to have a very small effect on the capacity of the crab shells for uptake of nickel. The effect of pH was also found not to be prominent.

  20. Hermit crabs perceive the extent of their virtual bodies.

    PubMed

    Sonoda, Kohei; Asakura, Akira; Minoura, Mai; Elwood, Robert W; Gunji, Yukio-P

    2012-08-23

    A flexible body image is required by animals if they are to adapt to body changes and move effectively within a structurally complex environment. Here, we show that terrestrial hermit crabs, Coenobita rugosus, which frequently change shells, can modify walking behaviour, dependent on the shape of the shell. Hermit crabs walked along a corridor that had alternating left and right corners; if it was narrow at the corner, crabs rotated their bodies to avoid the wall, indicating an awareness of environmental obstacles. This rotation increased when a plastic plate was attached to the shell. We suggest that the shell, when extended by the plate, becomes assimilated to the hermit crab's own body. While there are cases of a tool being assimilated with the body, our result is the first example of the habitat where an animal lives and/or carries being part of a virtual body. PMID:22378741

  1. Crab-mediated phenotypic changes in Spartina densiflora Brong.

    NASA Astrophysics Data System (ADS)

    Bortolus, Alejandro; Laterra, Pedro; Iribarne, Oscar

    2004-01-01

    Although plant phenotypic plasticity has been historically studied as an important adaptive strategy to overcome herbivory and environmental heterogeneity, there are several aspects of its ecological importance that remain controversial. The burrowing crab Chasmagnathus granulata eats Spartina densiflora, and also causes several geomorphologic changes that indirectly affect Spartina growth. Here we evaluate if this crab affects the sexual reproductive effort of S. densiflora by mediating changes in plant phenotypic plasticity (i.e., shape of leaves and spikes) while affecting aboveground production, and if these effects interact with disturbance intensity. We conducted local and regional surveys and two-year field experiments manipulating the density of crabs in a mature Spartina marsh where we clipped at ground level different 1×1 m marsh areas to create and compare crab's effect on young (plants growing after the clipping) and mature (unclipped) Spartina stands. Our results suggest that crabs mediate the phenotypic plasticity of sexual reproductive structures of Spartina. Crabs induced an increase in seed production (up to 721%) and seed viability, potentially favoring Spartina dispersal and colonization of distant sites. This effect appears to be maximal when combined with the experimental clipping disturbance. Crabs also exerted a strong effect on clipped plants by increasing the number of standing dead stems and decreasing the photosynthetic area and leaf production. These effects disappear in about two years if no other disturbance occurs. An a posteriori regional field survey agreed with our experimental results corroborating the prediction that plants in old undisturbed marshes have lower sexual reproductive effort than plants in highly disturbed marshes populated by burrowing-herbivore crabs. All these phenotypic changes have important taxonomic and macro-ecological implications that should not be ignored in discussions of applied ecology and

  2. A novel bacterial infection of the edible crab, Cancer pagurus.

    PubMed

    Thrupp, Tara J; Whitten, Miranda M A; Rowley, Andrew F

    2016-01-01

    There are few reports of bacterial diseases in crabs. A juvenile edible crab (Cancer pagurus) with a rickettsial-like infection was found in the intertidal zone at Freshwater East in South West Wales in July, 2012. Large numbers of bacteria-like particles were found in the haemolymph and within fixed phagocytes of the hepatopancreas. Molecular sequencing and subsequent phylogenetic analysis showed that the infectious agent was a member of the order Rhizobiales and therefore distinct to bacteria classified as rickettsia.

  3. Design of Superconducting Parallel Bar Deflecting and Crabbing rf Structures

    SciTech Connect

    Jean Delayen, Haipeng Wang

    2009-05-01

    A new concept for a deflecting and crabbing rf structure based on half-wave resonant lines was introduced recently*. It offers significant advantages to existing designs and, because of it compactness, allows low frequency operation. This concept has been further refined and optimized for superconducting implementation. Results of this optimization and application to a 400 MHz crabbing cavity and a 499 MHz deflecting cavity are presented.

  4. 50 CFR Table 8 to Part 680 - Initial QS and PQS Pool for Each Crab QS Fishery

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Crab QS Fishery Crab QS Fishery Initial QS Pool Initial PQS Pool BBR Bristol Bay red king crab 400,000... Islands golden king crab 10,000,000 10,000,000 EBT Eastern Bering Sea Tanner crab (C. bairdi) 200,000,000 200,000,000 PIK Pribilof Islands red and blue king crab 30,000,000 30,000,000 SMB St. Matthew...

  5. Final Report for "Compact Crab Cavity Design"

    SciTech Connect

    Smithe, David N

    2012-11-08

    The goal of this project is to provide an innovative, new crab cavity design relevant to the MEIC. Through this work, we will provide comprehensive modeling of this new cavity design, including electromagnetic, thermal, and microphonic effects. One most likely candidate configuration is the design put forward by JLab and Lancaster University, UK, researchers known as the four-rod configuration. In the Phase I, Tech-X Corporation researchers performed analysis and design optimization and iteration, utilizing their state-of-the art time-domain particle-in-cell software, on a 400 MHz design for the LHC by JLab and Lancaster University, UK, researchers known as the four-rod design.

  6. Phylogenetics of Cancer crabs (Crustacea: Decapoda: Brachyura).

    PubMed

    Harrison, M K; Crespi, B J

    1999-07-01

    We used morphological, mitochondrial DNA sequence, paleontological, and biogeographical information to examine the evolutionary history of crabs of the genus Cancer. Phylogenies inferred from adult morphology and DNA sequence of the cytochrome oxidase I (COI) gene were each well resolved and well supported, but differed substantially in topology. Four lines of evidence suggested that the COI data set accurately reflected Cancer phylogeny: (1) in the phylogeny inferred from morphological data, each Atlantic species was sister taxon to an ecologically similar Pacific species, suggesting convergence in morphology; (2) a single trans-Arctic dispersal event, as indicated by the phylogeny inferred from COI, is more parsimonious than two such dispersal events, as inferred from morphology; (3) test and application of a maximum likelihood molecular clock to the COI data yielded estimates of origin and speciation times that fit well with the fossil record; and (4) the tree inferred from the combined COI and morphology data was closely similar to the trees inferred from COI, although notably less well supported by the bootstrap. The phylogeny inferred from maximum likelihood analysis of COI suggested that Cancer originated in the North Pacific in the early Miocene, that the Atlantic species arose from a North Pacific ancestor, and that Cancer crabs invaded the Atlantic from the North Pacific 6-12 mya. This inferred invasion time is notably prior to most estimates of the date of submergence of the Bering Strait and the trans-Arctic interchange, but it agrees with fossil evidence placing at least one Cancer species in the Atlantic about 8 mya. PMID:10381321

  7. Plastic and Heritable Variation in Shell Thickness of the Intertidal Gastropod Nucella lapillus Associated with Risks of Crab Predation and Wave Action, and Sexual Maturation

    PubMed Central

    Pascoal, Sonia; Carvalho, Gary; Creer, Simon; Mendo, Sonia; Hughes, Roger

    2012-01-01

    The intertidal snail Nucella lapillus generally has thicker shells at sites sheltered from wave action, where crabs are abundant and pose a high risk of predation, than at exposed sites where crabs are rare. We studied two populations showing the opposite trend. We reciprocally transplanted snails between field sites and measured shell length, width and lip thickness of those recaptured 12 months later. Snails transplanted to the sheltered site grew larger than sheltered-site residents, which in turn grew larger than transplants to the exposed site. Relative shell-lip thickness was greater in residents at the exposed site than at the sheltered site. Transplants from shelter to exposure developed relatively thicker shells than their controls and relatively thinner shells from exposure to shelter. Progeny of the two populations were reared for 12 months in a common garden experiment presenting effluent from crabs feeding on broken conspecifics as the treatment and fresh sea-water as the control. The crab-effluent treatment decreased foraging activity, concomitantly reducing cumulative somatic growth and reproductive output. Juveniles receiving crab-effluent grew slower in shell length while developing relatively thicker shell lips than controls, the level of response being similar between lineages. F2 progeny of the exposed-site lineage showed similar trends to the F1s; sheltered-site F2s were too few for statistical analysis. At sexual maturity, shell-lip thickness was greater in snails receiving crab-effluent than in controls, indicating plasticity, but was also greater in the exposed-site than in the sheltered-site lineage, indicating heritable variation, probably in degree of sexual thickening of the shell lip. Results corroborate hypotheses that ‘defensive’ shell thickening is a passive consequence of starvation and that heritable and plastic control of defensive shell morphology act synergistically. Shell thickening of juveniles was similar between lineages

  8. Starfish and horseshoe crab egg factors cause elevations of cyclic nucleotide concentrations in spermatozoa from starfish and horseshoe crabs.

    PubMed

    Tubb, D J; Kopf, G S; Garbers, D L

    1979-07-01

    Factors collected from the eggs of the starfish (Pisaster giganteus) and the horsehoe crab (Limulus polyphemus) caused significant increases in the sperm cyclic nucleotide concentrations of the respective species. Sea urchin egg factors, at concentrations that resulted in maximal cyclic nucleotide elevations in sea urchin spermatozoa, had no effect on those of starfish or horseshoe crab, suggesting a species specificity with respect to egg factor-induced changes in sperm cyclic nucleotide metabolism.

  9. Recruitment variation of eastern Bering Sea crabs: Climate-forcing or top-down effects?

    NASA Astrophysics Data System (ADS)

    Zheng, Jie; Kruse, Gordon H.

    2006-02-01

    During the last three decades, population abundances of eastern Bering Sea (EBS) crab stocks fluctuated greatly, driven by highly variable recruitment. In recent years, abundances of these stocks have been very low compared to historical levels. This study aims to understand recruitment variation of six stocks of red king ( Paralithodes camtschaticus), blue king ( P. platypus), Tanner ( Chionoecetes bairdi), and snow ( C. opilio) crabs in the EBS. Most crab recruitment time series are not significantly correlated with each other. Spatial distributions of three broadly distributed crab stocks (EBS snow and Tanner crabs and Bristol Bay red king crab) have changed considerably over time, possibly related in part to the regime shift in climate and physical oceanography in 1976-1977. Three climate-forcing hypotheses on larval survival have been proposed to explain crab recruitment variation of Bristol Bay red king crab and EBS Tanner and snow crabs. Some empirical evidence supports speculation that groundfish predation may play an important role in crab recruitment success in the EBS. However, spatial dynamics in the geographic distributions of groundfish and crabs over time make it difficult to relate crab recruitment strength to groundfish biomass. Comprehensive field and spatially explicit modeling studies are needed to test the hypotheses and better understand the relative importance and compound effects of bottom-up and top-down controls on crab recruitment.

  10. Glutamate and GABA activate different receptors and Cl(-) conductances in crab peptide-secretory neurons.

    PubMed

    Duan, S; Cooke, I M

    2000-01-01

    Responses to rapid application of glutamic acid (Glu) and gamma-aminobutyric acid (GABA), 0.01-3 mM, were recorded by whole-cell patch clamp of cultured crab (Cardisoma carnifex) X-organ neurons. Responses peaked within 200 ms. Both Glu and GABA currents had reversal potentials that followed the Nernst Cl(-) potential when [Cl(-)](i) was varied. A Boltzmann fit to the normalized, averaged dose-response curve for Glu indicated an EC(50) of 0.15 mM and a Hill coefficient of 1.05. Rapid (t(1/2) approximately 1 s) desensitization occurred during Glu but not GABA application that required >2 min for recovery. Desensitization was unaffected by concanavalin A or cyclothiazide. N-methyl-D-aspartate, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, quisqualate, and kainate (to 1 mM) were ineffective, nor were Glu responses influenced by glycine (1 microM) or Mg(2+) (0-26 mM). Glu effects were imitated by ibotenic acid (0.1 mM). The following support the conclusion that Glu and GABA act on different receptors: 1) responses sum; 2) desensitization to Glu or ibotenic acid did not diminish GABA responses; 3) the Cl(-)-channel blockers picrotoxin and niflumic acid (0.5 mM) inhibited Glu responses by approximately 90 and 80% but GABA responses by approximately 50 and 20%; and 4) polyvinylpyrrolydone-25 (2 mM in normal crab saline) eliminated Glu responses but left GABA responses unaltered. Thus crab secretory neurons have separate receptors responsive to Glu and to GABA, both probably ionotropic, and mediating Cl(-) conductance increases. In its responses and pharmacology, this crustacean Glu receptor resembles Cl(-)-permeable Glu receptors previously described in invertebrates and differs from cation-permeable Glu receptors of vertebrates and invertebrates.

  11. Molecular cloning and characterization of a heat shock protein 70 gene in swimming crab (Portunus trituberculatus).

    PubMed

    Cui, Zhaoxia; Liu, Yuan; Luan, Weisha; Li, Qianqian; Wu, Danhua; Wang, Shuangyan

    2010-01-01

    Hsp70 can stimulate cells of the innate immune system directly by acting as "danger"-signaling molecules. To understand the immune defense mechanisms of swimming crab Portunus trituberculatus (Decapoda: Brachyura: Portunidae), the cDNA of Hsp70 (designated PtHsp70) was cloned by the combination of homology cloning and rapid amplification of cDNA ends (RACE). The full-length PtHsp70 cDNA was 2195 bp, including an open reading frame (ORF) of 1950 bp encoding a polypeptide of 650 amino acids with estimated molecular mass of 71.1514 kDa and theoretical isoelectric point of 5.38. FASTA and BLAST analysis indicated that PtHsp70 should be an inducible cytosolic member of the Hsp70 family. The coding region of PtHsp70 was uninterrupted and four SNPs with 1133C/T, 1311C/T, 1551C/T and 1809 A/G were detected by direct sequencing of 20 genomic samples. Using fluorescent real-time quantitative PCR, the transcriptional expression of PtHsp70 showed a clear time-dependent response after challenge by Vibrio alginolyticus, the main causative agent of emulsification disease causing large mortality in P. trituberculatus. This is the first report on the expression of Hsp70 induced by pathogen stimulation in Brachyura. Phylogenetic analysis revealed that the inducible Hsp70s were divided into two groups in crab and PtHsp70 was clustered into the Hsp/Hsc group (Clade I) by maximum-likelihood (ML) and Bayesian inference (BI) methods. GAP repeat and GGMP motif of inducible Hsp70 gene in the crab species were only found in Clade I. PMID:19815077

  12. Maine belowground marsh destruction from the European green crab documented by computer-aided tomography

    EPA Science Inventory

    Invasive European green crab (Carcinus maenus) populations have exploded with devastating losses to Maine’s intertidal resources including soft-shell clams, eelgrass beds, and salt marshes. This project quantified the green crab abundance in three different marsh locations ...

  13. 76 FR 4635 - Proposed Information Collection; Comment Request; Economic Expenditure Survey of Golden Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... Expenditure Survey of Golden Crab Fishermen in the U.S. South Atlantic Region AGENCY: National Oceanic and... National Marine Fisheries Service (NMFS) proposes to collect economic information from golden-crab...

  14. Neural organization of the second optic neuropil, the medulla, in the highly visual semiterrestrial crab Neohelice granulata.

    PubMed

    Sztarker, Julieta; Tomsic, Daniel

    2014-10-01

    Crustaceans are widely distributed and inhabit very different niches. Many of them are highly visual animals. Nevertheless, the neural composition of crustacean optic neuropils deeper than the lamina is mostly unknown. In particular, semiterrestrial crabs possess a highly developed visual system and display conspicuous visually guided behaviors. A previous study shows that the first optic neuropil, the lamina of the crab Neohelice granulata, possesses a surprisingly high number of elements in each cartridge. Here, we present a comprehensive description of individual elements composing the medulla of that same species. Using Golgi impregnation, we characterized a wide variety of cells. Only considering the class of transmedullary neurons, we describe over 50 different morphologies including small- and large-field units. Among others, we describe a type of centrifugal neuron hitherto not identified in other crustaceans or insects that probably feeds back information to every cartridge in the medulla. The possible functional role of such centrifugal elements is discussed in connection with the physiological and behavioral information on visual processing available for this crab. Taken together, the results reveal a very dense and complex neuropil in which several channels of information processing would be acting in parallel. We further examine our results considering the similarities and differences found between the layered organization and components of this crustacean medulla and the medullae of insects.

  15. Design and prototyping of HL-LHC double quarter wave crab cavities for SPS test

    SciTech Connect

    Verdu-Andres, S.; Skaritka, J.; Wu, Q.; Xiao, B.; Belomestnykh, S.; Ben-Zvi, I.; Alberty, L.; Artoos, K.; Calaga, R.; Capatina, O.; Capelli, T.; Carra, F.; Leuxe, R.; Kuder, N.; Zanoni, C.; Li, Z.; Ratti, A.

    2015-05-03

    The LHC high luminosity project envisages the use of the crabbing technique for increasing and levelling the LHC luminosity. Double Quarter Wave (DQW) resonators are compact cavities especially designed to meet the technical and performance requirements for LHC beam crabbing. Two DQW crab cavities are under fabrication and will be tested with beam in the Super Proton Synchrotron (SPS) at CERN by 2017. This paper describes the design and prototyping of the DQW crab cavities for the SPS test.

  16. Location of volatile odor sources by ghost crabOcypode quadrata (Fabricius).

    PubMed

    Wellins, C A; Rittschof, D; Wachowiak, M

    1989-04-01

    The ghost crab,Ocypode quadrata, was tested in the field for its ability to locate sources of volatile cues. The pure compound skatole, 3-methylindole, was a potent attractant. Crabs also located sources of complex odors such as dead fish,Lutjanus campechanus, dead mole crabs,Emerita talpoida; and peeled bananas. Ghost crabs possess concealed and reduced antennules that may not be the primary olfactory organs. Chemosensory hairs borne on the dactyls may be the primary detection system.

  17. Sediment dynamics modulated by burrowing crab activities in contrasting SW Atlantic intertidal habitats

    NASA Astrophysics Data System (ADS)

    Escapa, Mauricio; Perillo, Gerardo M. E.; Iribarne, Oscar

    2008-11-01

    Biogenic bottom features, animal burrows and biological activities interact with the hydrodynamics of the sediment-water interface to produce altered patterns of sediment erosion, transport and deposition which have consequences for large-scale geomorphologic features. It has been suggested that depending on the hydrodynamic status of the habitat, the biological activity on the bottom may have a variety of effects. In some cases, different bioturbation activities by the same organism can result in different consequences. The burrowing crab Neohelice granulata is the most important bioturbator at SW Atlantic saltmarshes and tidal plains. Because of the great variety of habitats that this species may inhabit, it is possible to compare its bioturbation effects between zones dominated by different hydrodynamic conditions. Internal marsh microhabitats, tidal creeks bottoms and basins, and open mudflats were selected as contrasting zones for the comparison on a large saltmarsh at Bahía Blanca Estuary (Argentina). Crab burrows act as passive traps of sediment in all zones, because their entrances remain open during inundation periods at high tide. Mounds are generated when crabs remove sediments from the burrows to the surface and become distinctive features in all the zones. Two different mechanisms of sediment transport utilizing mounds as sediment sources were registered. In the first one, parts of fresh mound sediments were transported when exposed to water flow during flooding and ebbing tide, with higher mound erosion where currents were higher as compared to internal marsh habitats and open mudflats. In the second mechanism, mounds exposed to atmospheric influence during low tide became desiccated and cracked forming ellipsoidal blocks, which were then transported by currents in zones of intense water flow in the saltmarsh edge. Sedimentary dynamics varied between zones; crabs were promoting trapping of sediments in the internal saltmarsh (380 g m -2 day -1) and

  18. 50 CFR 648.262 - Accountability measures for red crab limited access vessels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Accountability measures for red crab... UNITED STATES Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.262 Accountability measures for red crab limited access vessels. (a) Closure authority. NMFS shall close the EEZ to...

  19. 50 CFR Table 3a to Part 680 - Crab Delivery Condition Codes

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Crab Delivery Condition Codes 3a Table 3a... ZONE OFF ALASKA Pt. 680, Table 3a Table 3a to Part 680—Crab Delivery Condition Codes Code Description 01 Whole crab, live. 79 Deadloss....

  20. 50 CFR 622.17 - South Atlantic golden crab controlled access.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false South Atlantic golden crab controlled... ATLANTIC Effort Limitations § 622.17 South Atlantic golden crab controlled access. (a) General. In accordance with the procedures specified in the Fishery Management Plan for the Golden Crab Fishery of...

  1. 50 CFR Table 3c to Part 680 - Crab Product Codes for Economic Data Reports

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Product Codes for Economic Data... EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680, Table 3c Table 3c to Part 680—Crab Product Codes for Economic Data Reports Code Description 01 Whole crab. 80 Sections. 81 Meats. 97 Other (specify)....

  2. 50 CFR 648.262 - Accountability measures for red crab limited access vessels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Accountability measures for red crab... UNITED STATES Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.262 Accountability measures for red crab limited access vessels. (a) Closure authority. NMFS shall close the EEZ to...

  3. 50 CFR Table 3a to Part 680 - Crab Delivery Condition Codes

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab Delivery Condition Codes 3a Table 3a... ZONE OFF ALASKA Pt. 680, Table 3a Table 3a to Part 680—Crab Delivery Condition Codes Code Description 01 Whole crab, live. 79 Deadloss....

  4. 78 FR 21912 - Proposed Information Collection; Comment Request; Crab Rationalization (CR) Program: Annual Report

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... National Oceanic and Atmospheric Administration Proposed Information Collection; Comment Request; Crab... collection. Since implementation of the Crab Rationalization (CR) Program (prior to the 2005-2006 season... vessel owners and crews. Crews in the crab fisheries are typically paid a share (or percentage)...

  5. 50 CFR 622.17 - South Atlantic golden crab controlled access.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false South Atlantic golden crab controlled... ATLANTIC Effort Limitations § 622.17 South Atlantic golden crab controlled access. (a) General. In accordance with the procedures specified in the Fishery Management Plan for the Golden Crab Fishery of...

  6. 50 CFR Table 3c to Part 680 - Crab Product Codes for Economic Data Reports

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Product Codes for Economic Data... EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680, Table 3c Table 3c to Part 680—Crab Product Codes for Economic Data Reports Code Description 01 Whole crab. 80 Sections. 81 Meats. 97 Other (specify)....

  7. 50 CFR Table 3c to Part 680 - Crab Product Codes for Economic Data Reports

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab Product Codes for Economic Data... EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 680, Table 3c Table 3c to Part 680—Crab Product Codes for Economic Data Reports Code Description 01 Whole crab. 80 Sections. 81 Meats. 97 Other (specify)....

  8. 50 CFR 648.262 - Accountability measures for red crab limited access vessels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Accountability measures for red crab... UNITED STATES Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.262 Accountability measures for red crab limited access vessels. (a) Closure authority. NMFS shall close the EEZ to...

  9. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  10. 50 CFR Table 3a to Part 680 - Crab Delivery Condition Codes

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Delivery Condition Codes 3a Table 3a... ZONE OFF ALASKA Pt. 680, Table 3a Table 3a to Part 680—Crab Delivery Condition Codes Code Description 01 Whole crab, live. 79 Deadloss....

  11. 50 CFR 622.241 - South Atlantic golden crab controlled access.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false South Atlantic golden crab controlled..., AND SOUTH ATLANTIC Golden Crab Fishery of the South Atlantic Region § 622.241 South Atlantic golden crab controlled access. (a) General. In accordance with the procedures specified in the...

  12. 50 CFR Table 3a to Part 680 - Crab Delivery Condition Codes

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Crab Delivery Condition Codes 3a Table 3a... ZONE OFF ALASKA Pt. 680, Table 3a Table 3a to Part 680—Crab Delivery Condition Codes Code Description 01 Whole crab, live. 79 Deadloss....

  13. 50 CFR Table 3a to Part 680 - Crab Delivery Condition Codes

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Delivery Condition Codes 3a Table 3a... ZONE OFF ALASKA Pt. 680, Table 3a Table 3a to Part 680—Crab Delivery Condition Codes Code Description 01 Whole crab, live. 79 Deadloss....

  14. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  15. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  16. 50 CFR 622.241 - South Atlantic golden crab controlled access.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false South Atlantic golden crab controlled..., AND SOUTH ATLANTIC Golden Crab Fishery of the South Atlantic Region § 622.241 South Atlantic golden crab controlled access. (a) General. In accordance with the procedures specified in the...

  17. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  18. 50 CFR 622.17 - South Atlantic golden crab controlled access.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false South Atlantic golden crab controlled... ATLANTIC Effort Limitations § 622.17 South Atlantic golden crab controlled access. (a) General. In accordance with the procedures specified in the Fishery Management Plan for the Golden Crab Fishery of...

  19. 50 CFR 648.262 - Accountability measures for red crab limited access vessels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Accountability measures for red crab... UNITED STATES Management Measures for the Atlantic Deep-Sea Red Crab Fishery § 648.262 Accountability measures for red crab limited access vessels. (a) Closure authority. NMFS shall close the EEZ to...

  20. 40 CFR 408.50 - Applicability; description of the remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... remote Alaskan crab meat processing subcategory. 408.50 Section 408.50 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Remote Alaskan Crab Meat Processing Subcategory § 408.50 Applicability; description of the remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  1. 40 CFR 408.30 - Applicability; description of the mechanized blue crab processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mechanized blue crab processing subcategory. 408.30 Section 408.30 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Blue Crab Processing Subcategory § 408.30 Applicability; description of the mechanized blue crab processing subcategory. The provisions of this subpart are applicable to...

  2. 40 CFR 408.20 - Applicability; description of the conventional blue crab processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... conventional blue crab processing subcategory. 408.20 Section 408.20 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Conventional Blue Crab Processing Subcategory § 408.20 Applicability; description of the conventional blue crab processing subcategory. The provisions of this subpart are applicable to...

  3. 50 CFR 600.1103 - Bering Sea and Aleutian Islands (BSAI) Crab species program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Sound blue king crab. NVDC means the U.S. Coast Guard's National Vessel Documentation Center located in...) Crab species program. 600.1103 Section 600.1103 Wildlife and Fisheries FISHERY CONSERVATION AND... Aleutian Islands (BSAI) Crab species program. (a) Purpose. This section's purpose is to implement...

  4. 40 CFR 408.30 - Applicability; description of the mechanized blue crab processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mechanized blue crab processing subcategory. 408.30 Section 408.30 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Blue Crab Processing Subcategory § 408.30 Applicability; description of the mechanized blue crab processing subcategory. The provisions of this subpart are applicable to...

  5. 76 FR 25545 - Safety Zone; Blue Crab Festival Fireworks Display, Little River, Little River, SC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-05

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Blue Crab Festival Fireworks Display... Carolina during the Blue Crab Festival Fireworks Display on Friday, ] May 13, 2011. The safety zone is... this rule because the Coast Guard did not receive notice of the Blue Crab Festival Fireworks...

  6. 50 CFR Table 1 to Part 680 - Crab Rationalization (CR) Fisheries

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Pribilof red king and blue king crab (Paralithodes camtshaticus and P. platypus) In waters of the EEZ with..., February 23, 1991) and NOAA Chart No. 514 (6th edition, February 16, 1991). SMB St. Matthew blue king crab... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Rationalization (CR) Fisheries...

  7. 40 CFR 408.30 - Applicability; description of the mechanized blue crab processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mechanized blue crab processing subcategory. 408.30 Section 408.30 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Blue Crab Processing Subcategory § 408.30 Applicability; description of the mechanized blue crab processing subcategory. The provisions of this subpart are applicable to...

  8. 40 CFR 408.30 - Applicability; description of the mechanized blue crab processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mechanized blue crab processing subcategory. 408.30 Section 408.30 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Blue Crab Processing Subcategory § 408.30 Applicability; description of the mechanized blue crab processing subcategory. The provisions of this subpart are applicable to...

  9. 40 CFR 408.20 - Applicability; description of the conventional blue crab processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... conventional blue crab processing subcategory. 408.20 Section 408.20 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Conventional Blue Crab Processing Subcategory § 408.20 Applicability; description of the conventional blue crab processing subcategory. The provisions of this subpart are applicable to...

  10. 40 CFR 408.20 - Applicability; description of the conventional blue crab processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... conventional blue crab processing subcategory. 408.20 Section 408.20 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Conventional Blue Crab Processing Subcategory § 408.20 Applicability; description of the conventional blue crab processing subcategory. The provisions of this subpart are applicable to...

  11. 40 CFR 408.20 - Applicability; description of the conventional blue crab processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... conventional blue crab processing subcategory. 408.20 Section 408.20 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Conventional Blue Crab Processing Subcategory § 408.20 Applicability; description of the conventional blue crab processing subcategory. The provisions of this subpart are applicable to...

  12. A comparison of different processing methods for picked blue crab (Callinectes sapidus).

    PubMed

    Senkel, I Arthur; Jolbitado, Beverly; Butler, Erin M; Rippen, Thomas E

    2005-02-01

    Five methods for producing picked crab meat from cooked blue crab (Callinectes sapidus) were evaluated for internal food temperatures and bacterial numbers at various process points. Whole shell-on crabs, crab cores ("backed" crabs with carapace removed), and crab meat samples were analyzed for standard plate count, total coliforms, fecal coliforms, Escherichia coli, and Staphylococcus aureus. For three of the processes, crabs were backed and washed a substantial time before picking; one of the processes used an ice slush dip to cool cooked crabs. Except for a single crab sample, bacteria were not isolated from crab and core samples. Standard plate count, E. coli, and S. aureus in crab meat samples from the different processes were statistically the same. Bacterial numbers in fresh picked crab meat samples exposed to an ambient temperature of 20 to 21.1 degrees C for 1.5 and 3.5 h and stored at 1 degrees C for 3 to 4 days and 7 to 8 days did not significantly differ (P < 0.05).

  13. 40 CFR 408.30 - Applicability; description of the mechanized blue crab processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mechanized blue crab processing subcategory. 408.30 Section 408.30 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Mechanized Blue Crab Processing Subcategory § 408.30 Applicability; description of the mechanized blue crab processing subcategory. The provisions of this subpart are applicable to...

  14. 40 CFR 408.20 - Applicability; description of the conventional blue crab processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conventional blue crab processing subcategory. 408.20 Section 408.20 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Conventional Blue Crab Processing Subcategory § 408.20 Applicability; description of the conventional blue crab processing subcategory. The provisions of this subpart are applicable to...

  15. 50 CFR Table 1 to Part 680 - Crab Rationalization (CR) Fisheries

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Pribilof red king and blue king crab (Paralithodes camtshaticus and P. platypus) In waters of the EEZ with..., February 23, 1991) and NOAA Chart No. 514 (6th edition, February 16, 1991). SMB St. Matthew blue king crab... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Crab Rationalization (CR) Fisheries...

  16. Patterns of activity expressed by juvenile horseshoe crabs.

    PubMed

    Dubofsky, E A; Simpson, S D; Chabot, Christopher C; Watson, Winsor H

    2013-09-01

    Adult American horseshoe crabs, Limulus polyphemus, possess endogenous circadian and circatidal clocks controlling visual sensitivity and locomotion, respectively. The goal of this study was to determine the types of activity rhythms expressed by juvenile horseshoe crabs (n = 24) when exposed to a 14:10 light/dark cycle (LD) for 10 days, followed by 10 days of constant darkness (DD). Horseshoe crab activity was recorded with a digital time-lapse video system that used an infrared-sensitive camera so animals could be monitored at night. In LD, 15 animals expressed daily patterns of activity, 6 displayed a circatidal pattern, and the remaining 3 were arrhythmic. Of the 15 animals with daily patterns of locomotion, 7 had a significant preference (P < 0.05) for diurnal activity and 3 for nocturnal activity; the remainder did not express a significant preference for day or night activity. In DD, 13 horseshoe crabs expressed circatidal rhythms and 8 maintained a pattern of about 24 h. Although these results suggest the presence of a circadian clock influencing circatidal patterns of locomotion, these apparent circadian rhythms may actually represent the expression of just one of the two bouts of activity driven by the putative circalunidian clocks that control their tidal rhythms. Overall, these results indicate that, like adults, juvenile horseshoe crabs express both daily and tidal patterns of activity and that at least one, and maybe both, of these patterns is driven by endogenous clocks. PMID:24088795

  17. Patterns of activity expressed by juvenile horseshoe crabs.

    PubMed

    Dubofsky, E A; Simpson, S D; Chabot, Christopher C; Watson, Winsor H

    2013-09-01

    Adult American horseshoe crabs, Limulus polyphemus, possess endogenous circadian and circatidal clocks controlling visual sensitivity and locomotion, respectively. The goal of this study was to determine the types of activity rhythms expressed by juvenile horseshoe crabs (n = 24) when exposed to a 14:10 light/dark cycle (LD) for 10 days, followed by 10 days of constant darkness (DD). Horseshoe crab activity was recorded with a digital time-lapse video system that used an infrared-sensitive camera so animals could be monitored at night. In LD, 15 animals expressed daily patterns of activity, 6 displayed a circatidal pattern, and the remaining 3 were arrhythmic. Of the 15 animals with daily patterns of locomotion, 7 had a significant preference (P < 0.05) for diurnal activity and 3 for nocturnal activity; the remainder did not express a significant preference for day or night activity. In DD, 13 horseshoe crabs expressed circatidal rhythms and 8 maintained a pattern of about 24 h. Although these results suggest the presence of a circadian clock influencing circatidal patterns of locomotion, these apparent circadian rhythms may actually represent the expression of just one of the two bouts of activity driven by the putative circalunidian clocks that control their tidal rhythms. Overall, these results indicate that, like adults, juvenile horseshoe crabs express both daily and tidal patterns of activity and that at least one, and maybe both, of these patterns is driven by endogenous clocks.

  18. Radio emission physics in the Crab pulsar

    NASA Astrophysics Data System (ADS)

    Eilek, Jean A.; Hankins, Timothy H.

    2016-06-01

    > We review our high-time-resolution radio observations of the Crab pulsar and compare our data to a variety of models for the emission physics. The Main Pulse and the Low Frequency Interpulse come from regions somewhere in the high-altitude emission zones (caustics) that also produce pulsed X-ray and -ray emission. Although no emission model can fully explain these two components, the most likely models suggest they arise from a combination of beam-driven instabilities, coherent charge bunching and strong electromagnetic turbulence. Because the radio power fluctuates on a wide range of time scales, we know the emission zones are patchy and dynamic. It is tempting to invoke unsteady pair creation in high-altitude gaps as the source of the variability, but current pair cascade models cannot explain the densities required by any of the likely models. It is harder to account for the mysterious High Frequency Interpulse. We understand neither its origin within the magnetosphere nor the striking emission bands in its dynamic spectrum. The most promising models are based on analogies with solar zebra bands, but they require unusual plasma structures which are not part of our standard picture of the magnetosphere. We argue that radio observations can reveal much about the upper magnetosphere, but work is required before the models can address all of the data.

  19. ELEMENT DISTRIBUTIONS IN THE CRAB NEBULA

    SciTech Connect

    Satterfield, Timothy J.; Katz, Andrea M.; Sibley, Adam R.; MacAlpine, Gordon M.; Uomoto, Alan

    2012-07-15

    Images of the Crab Nebula have been obtained through custom interference filters that transmit emission from the expanding supernova remnant in He II {lambda}4686, H{beta}, He I {lambda}5876, [O I] {lambda}{lambda}6300, 6364, [N II] {lambda}{lambda}6548, 6583, [S II] {lambda}{lambda}6716, 6731, [S III] {lambda}9069, and [C I] {lambda}{lambda}9823, 9850. We present both raw and flux-calibrated emission-line images. Arrays of 19,440 photoionization models, with extensive input abundance ranges, were matched pixel by pixel to the calibrated data in order to derive corresponding element abundance or mass-fraction distributions for helium, carbon, nitrogen, oxygen, and sulfur. These maps show distinctive structure, and they illustrate regions of gas in which various stages of nucleosynthesis have apparently occurred, including the CNO cycle, helium burning, carbon burning, and oxygen burning. It is hoped that the calibrated observations and chemical abundance distribution maps will be useful for developing a better understanding of the precursor star evolution and the supernova explosive process.

  20. Unpulsed Optical Emission from the Crab Pulsar

    NASA Astrophysics Data System (ADS)

    Golden, A.; Shearer, A.; Beskin, G. M.

    2000-05-01

    Based on observations of the Crab pulsar using the TRIFFID high-speed imaging photometer in the UBV bands using the Special Astrophysical Observatory's 6 m telescope in the Russian Caucasus, we report the detection of pronounced emission during the so-called off phase of emission. Following de-extinction, this unpulsed component of emission is shown to be consistent with a power law with an exponent of α=-0.60+/-0.37, the uncertainty being dominated by the error associated with the independent CCD photometry used to reference the TRIFFID data. This suggests a steeper power-law form than that reported elsewhere in the literature for the total integrated spectrum, which is essentially flat with α~0.1, although the difference in this case is only significant at the <=2 σ level. Deeper reference integrated and TRIFFID phase-resolved photometry, in these bands in conjunction with further observations in the UV and R region, would constrain this fit further. Based on observations using the 6 m telescope at the Special Astrophysical Observatory of the Russian Academy of Sciences in Nizhnii Arkhyz, Russia.

  1. 75 FR 43147 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... Alaska; Bering Sea and Aleutian Islands Crab Rationalization Cost Recovery Program AGENCY: National... under the Bering Sea and Aleutian Islands Crab Rationalization Program. This action is intended to provide holders of crab allocations with the fee percentage for the 2010/2011 crab fishing year so...

  2. 76 FR 43658 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... Alaska; Bering Sea and Aleutian Islands Crab Rationalization Cost Recovery Program AGENCY: National... under the Bering Sea and Aleutian Islands Crab Rationalization Program. This action is intended to provide holders of crab allocations with the fee percentage for the 2011/2012 crab fishing year so...

  3. 76 FR 39369 - Fisheries of the Northeastern United States; Atlantic Deep-Sea Red Crab Fishery; Amendment 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... United States; Atlantic Deep-Sea Red Crab Fishery; Amendment 3 AGENCY: National Marine Fisheries Service... Crab Fishery Management Plan (Red Crab FMP). The New England Fishery Management Council (Council) developed Amendment 3 to bring the Red Crab FMP into compliance with the annual catch limit (ACL)...

  4. 77 FR 44216 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-27

    ... Alaska; Bering Sea and Aleutian Islands Crab Rationalization Cost Recovery Program AGENCY: National... recovery under the Bering Sea and Aleutian Islands Crab Rationalization Program. This action is intended to provide holders of crab allocations with the fee percentage for the 2012/2013 crab fishing year....

  5. 78 FR 46577 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-01

    ... Alaska; Bering Sea and Aleutian Islands Crab Rationalization Cost Recovery Program AGENCY: National... under the Bering Sea and Aleutian Islands Crab Rationalization Program. This action is intended to provide holders of crab allocations with the fee percentage for the 2013/2014 crab fishing year so...

  6. 76 FR 68358 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... Program, the western Aleutian Islands red king crab and Pribilof Islands red and blue king crab fisheries have failed to open, and the Saint Matthew Island blue king crab fishery has only been open during the... Economic Zone Off Alaska; Bering Sea and Aleutian Islands Crab Rationalization Program AGENCY:...

  7. Chandra Observations of the Crab: A Progress Report

    NASA Technical Reports Server (NTRS)

    Weisskopf, Martin C.

    2012-01-01

    Recently there have been two important findings concerning the Crab both of which are highlighted in this workshop. One finding was the discovery, using the AGILE and Fermi satellites, of gamma-ray flares from the direction of the Crab Nebula. The other finding was the variability, up to 7%, with time scales of the order of a year of the integrated hard X-ray emission. We have been using the Chandra X-Ray observatory to monitor the Crab on a monthly cadence since just after the 2010 September gamma-ray flare. We were also fortunate to trigger series of preplanned target of opportunity observations during the 2011 April flare. Our monitoring observations are on-going and will extend, at a minimum until the fall of 2012. We present an update and overview of these observations.

  8. [Study on the toxicity of horseshoe crabs in mice].

    PubMed

    Liao, Y; Li, X

    2000-05-30

    In order to study the toxicity of horseshoe crabs(tachypleus tridentatus and carcinoscorpius rotundicauda) in the sea of China, the extracts of tissues from tachypleus tridentatus and carcinoscorpius rotundicauda were injected into the abdominal cavity of mice for testing their poisoning effects. The results showed that the toxicity of carcinoscorpius rotundicauda was much higher than that of tachypleus tridentatus. The length of time from the injection to the death was much shorter for Carcinoscorpius rotundicauda than that for tachypleus tridentatus. The signs before death for Carcinoscorpius rotundicauda poisoning were restless, jumping and spasm but that for Tachypleus tridentatus was lethargy. The toxicity of adult horseshoe crabs was much higher than that of young horseshoe crabs.

  9. Respiration and heart rate in exercising land crabs.

    PubMed

    Herreid, C F; Lee, L W; Shah, G M

    1979-05-01

    Land Crabs, Cardisoma guanhumi, were fitted with respiratory masks and E.C.G. electrodes and run for 10 or 20 min on a treadmill at speeds of 150 and 300 cm/min. Aerobic metabolism increased linearly with the speed of locomotion. The recovery period was characterized by a large oxygen debt. The primary respiratory adjustment to exercise was an increased ventilation volume; only a minor increase in oxygen extraction occurred. The respiratory exchange ratio increased during exercise and during recovery, presumably correlated with a metabolic acidosis. These results are similar to data collected for exercising vertebrates and the net cost of locomotion of crabs appears similar to quadrupeds. However, the heart rate in exercising crabs changed in an unexpected way: during moderate exercise no change was noted, but during heavy exercise a bradycardia developed. The reduction in rate resulted from an increase in interbeat interval and frequent pauses in the heart beat.

  10. Extreme Particle Acceleration via Magnetic Reconnection in the Crab Nebula

    NASA Astrophysics Data System (ADS)

    Cerutti, Benoit; Uzdensky, D. A.; Begelman, M. C.

    2012-01-01

    The discovery by Agile and Fermi of intense day-long synchrotron gamma-ray flares above 100 MeV in the Crab Nebula challenges classical models of pulsar wind nebulae and particle acceleration. We argue that the flares are powered by magnetic reconnection in the nebula. Using relativistic test-particle simulations, we show that particles are naturally focused into a thin fan beam, deep inside the reconnection layer where the magnetic field is small. The particles then suffer less from synchrotron losses and pile up at the maximum energy given by the electric potential drop in the layer. Applying this model to the Crab Nebula, we find that the emerging synchrotron emission spectrum above 100 MeV is consistent with the September 2010 flare observations. No detectable emission is expected at other wavelengths. This scenario provides a viable explanation for the Crab Nebula gamma-ray flares.

  11. Preliminary survey of a nemertean crab egg predator, Carcinonemertes, on its host crab, Callinectes arcuatus (Decapoda, Portunidae) from Golfo de Nicoya, Pacific Costa Rica

    PubMed Central

    Okazaki, Robert K.; Wehrtmann, Ingo S.

    2014-01-01

    Abstract The possible presence of egg predators in brood masses of portunid crabs from Pacific Central America has not been studied yet. This survey reports the finding of a nemertean crab egg predator on the portunid crab, Callinectes arcuatus, from the Golfo de Nicoya, Pacific Costa Rica. Nemerteans were found in the egg masses of 26 out of the 74 crabs for a prevalence of 35%. The intensity (mean number of worms/ infected crab) was estimated to be 18 with a variance of 1–123 worms/infected crab. No nemerteans were observed either in the 19 Callinectes arcuatus from Golfo Dulce (southern Pacific coast) and the 10 Portunus asper from Herradura-Jaco (central Pacific coast). This nemertean is a member of the genus Carcinonemertes, which has been reported from the Caribbean coast of Panama. However, the encountered Carcinonemertes sp. is the first published finding and report from Costa Rica and Pacific Central America. PMID:25561848

  12. Complete mitochondrial genomes of three mitten crabs, Eriocheir sinensis, E. hepuensis, and E. japonica.

    PubMed

    Wang, Jun; Huang, Lei; Cheng, Qixuan; Lu, Guoqing; Wang, Chenghui

    2016-01-01

    Taxonomic classification of three mitten crabs (Eriocheir sinensis, E. hepuensis, and E. japonica) has long been controversial. In this study, the complete mitogenomes of the three crabs were reported. The three mitogenomes were conserved in the organization of genes with 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and 1 control region. Nucleotide variations among the crabs were identified in both coding and non-coding regions. In addition, variable numbers of tandem repeats in control region were identified in the mitten crabs. The mitogenome sequences provide a valuable resource to elucidate taxonomic relationship and evolutionary history of the three mitten crabs.

  13. Nematodes Infect, But Do Not Manipulate Digging By, Sand Crabs, Lepidopa benedicti

    PubMed Central

    Joseph, Meera; Faulkes, Zen

    2014-01-01

    We examined sand crabs (Lepidopa benedicti) for endoparasites, and found the only parasite consistently infecting the studied population were small nematodes. Because many nematodes have complex life cycles involving multiple hosts, often strongly manipulating their hosts, we hypothesized that nematodes alter the behavior of their sand crab hosts. We predicted that more heavily infected crabs would spend more time above sand than less heavily infected crabs. Our data indicate infection by nematodes was not correlated with duration of time crabs spent above sand. We also suggest that organisms living in sandy beaches may benefit from relatively low parasite loads due to the low diversity of species in the habitat. PMID:24916475

  14. Crab Burrows are Important Conduits for Groundwater Recharge in Bangladesh

    NASA Astrophysics Data System (ADS)

    Stahl, M.; Tarek, M. H.; Yeo, D. C.; Badruzzaman, A.; Harvey, C. F.

    2013-12-01

    Recent research suggests that recharge from man-made ponds may stimulate arsenic mobilization within Bangladeshi aquifers. Man-made ponds are widespread throughout Bangladesh and are generally underlain by low permeability clays that could potentially limit flow to the sandy aquifer below if they are not compromised by preferential flow paths. Animal borrows are one common type of preferential flow path through surface clays. Across the Ganges Delta, terrestrial crabs dig borrows, sometimes as long as 10 meters. In our study pond in Munshiganj, Bangladesh we found crab burrows extending through the surficial clays and down into the shallow aquifer spaced approximately every meter. We use these field observations along with a novel, coupled isotope and water balance model to quantify the fluxes into and out of the pond. We show that nearly all of the aquifer recharge from the pond is through crab burrows which have enhanced the hydraulic conductivity of the surficial sediments by several orders of magnitude. In addition we show that the recharging pond water is shifting the solute composition of water beneath the pond. We suggest that, as a result of crab burrows, young ponds may contribute large fluxes of recharge water whereas older ponds may contribute little recharge to the aquifer. All terrestrial crabs have gills that must remain moist to allow for respiration. So, to ensure an uninterrupted water source, their borrows must reach the maximum depth that the water table drops to seasonally after irrigation ceases and before the onset of the monsoon. Once a pond is installed crabs living within the sediments that now make up the new pond bottom would no longer need to construct burrows to ensure a constant supply of water. Over time, burrows that existed prior to pond construction can clog. Water balance data for an old pond at our study site indicates that this pond contributes less recharge than our newly constructed pond.

  15. Associational resistance protects mangrove leaves from crab herbivory

    NASA Astrophysics Data System (ADS)

    Erickson, Amy A.; Bell, Susan S.; Dawes, Clinton J.

    2012-05-01

    While associational defenses have been well documented in many plant and algal ecosystems, this study is the first to document associational resistance in mangroves. Mangrove tree crab (Aratus pisonii) density and herbivory on three life-stages of the red mangrove (Rhizophora mangle) were documented in pure red versus mixed-species and predominantly non-red mangrove stands containing black (Avicennia germinans) and white (Laguncularia racemosa) mangroves in 1999-2000 in Tampa Bay, Florida. This study first established that R. mangle is the focal species in the context of associational resistance because it is damaged more than either of the other mangrove species. Next, it was hypothesized that crab density and leaf damage on R. mangle would be lower when in mixed-species and predominantly non-red versus red mangrove stands. A non-significant trend suggested that crab density varies among stands, and crab damage on R. mangle leaves was significantly lower in mixed-species and non-red stands. Mechanisms to explain associational resistance were examined. Positive Pearson correlations between the percent of adult R. mangle in a stand and both crab density and R. mangle leaf damage provided support for the resource concentration hypothesis. Limited support was found for the attractant-decoy hypothesis because the total amount of damaged leaves of all mangrove species combined typically differed among stands, suggesting that crabs were not shifting to alternative mangrove species to offset reduced availability of R. mangle leaves. Finally, while R. mangle seedlings were shorter in non-red stands compared to others, intra-specific differences in R. mangle leaf chemistry and sclerophylly among stands failed to explain associational patterns. These combined results argue for the need for additional experiments to elucidate mechanisms responsible for defensive plant associations in mangrove ecosystems and to determine whether such associations could be of use in mangrove

  16. Habitat selection and energetics of the fiddler crab ( Uca tangeri)

    NASA Astrophysics Data System (ADS)

    Klaassen, Marcel; Ens, Bruno J.

    We tried to unravel the possible links between the skewed predation risk in Uca tangeri (where large individuals are more at risk from avian predators) and size-dependent changes in the physiology and habitat choice of this fiddler crab species. Over a transect running from low to high in the tidal zone of a beach in Mauritania, the temperature profile at various depths in the substrate, the water-table level of seep water, salt concentration of seep water, depth of the aerobic level, operative temperatures on the surface, and size distribution of crabs were assessed. In addition, resting metabolic rates, Q 10 and thermal and starvation tolerances were estimated. Going from low to high in the tidal zone, crab size and burrow depth increased. At the preferred burrowing depth, microclimatological conditions appeared to be equally favourable at all sites. At the surface, conditions were more favourable low in the tidal zone, where also food availability is sufficient to enable small crabs to forage in the vicinity of their burrows. Large crabs have higher energy requirements and are thereby forced to forage in flocks low in the tidal zone where food is probably more abundant. Low in the tidal zone, digging deeply is impossible as the aerobic layer is rather thin. Large crabs prefer living high in the tidal zone as (1) deep burrows ensure better protection against predators, (2) more time is available for digging holes and (3) the substrate is better suited for reproduction. Energy reserves in late summer ensured an average of 34 days of survival. It is argued that the allotment of energy to growth must be considerable even in reproducing animals; the rewards of growth being the disproportional increase in reproductive output with size.

  17. Crab scars reveal survival advantage of left-handed snails.

    PubMed

    Dietl, Gregory P; Hendricks, Jonathan R

    2006-09-22

    Biological asymmetries are important elements of the structure and function of many living organisms. Using the Plio-Pleistocene fossil record of crab predation on morphologically similar pairs of right- and left-handed snail species, we show here for the first time, contrary to traditional wisdom, that rare left-handed coiling promotes survival from attacks by right-handed crabs. This frequency-dependent result influences the balance of selection processes that maintain left-handedness at the species level and parallels some social interactions in human cultures, such as sports that involve dual contests between opponents of opposite handedness.

  18. Crab scars reveal survival advantage of left-handed snails

    PubMed Central

    Dietl, Gregory P; Hendricks, Jonathan R

    2006-01-01

    Biological asymmetries are important elements of the structure and function of many living organisms. Using the Plio–Pleistocene fossil record of crab predation on morphologically similar pairs of right- and left-handed snail species, we show here for the first time, contrary to traditional wisdom, that rare left-handed coiling promotes survival from attacks by right-handed crabs. This frequency-dependent result influences the balance of selection processes that maintain left-handedness at the species level and parallels some social interactions in human cultures, such as sports that involve dual contests between opponents of opposite handedness. PMID:17148425

  19. Ultraviolet Imaging Telescope observations of the Crab Nebula

    NASA Astrophysics Data System (ADS)

    Hennessy, Gregory S.; O'Connell, Robert W.; Cheng, Kwang P.; Bohlin, Ralph C.; Collins, Nicholas R.; Gull, Theodore R.; Hintzen, Paul; Isensee, Joan E.; Landsman, Wayne B.; Roberts, Morton S.; Smith, Andrew M.; Smith, Eric P.; Stecher, Theodore P.

    1992-08-01

    We obtained ultraviolet images of the Crab Nebula with the Ultraviolet Imaging Telescope during the Astro-1 Space Shuttle mission in 1990 December. The UV continuum morphology of the Crab is generally similar to that in the optical region, but the wispy structures are less conspicuous in the UV and X-ray. UV line emission from the thermal filaments is not strong. UV spectral index maps with a resolution of 10 arcsecs show a significant gradient across the nebula, with the outer parts being redder, as expected from synchrotron losses. The location of the bluest synchrotron continuum does not coincide with the pulsar.

  20. The use of artificial crabs for testing predatory behavior and health in the octopus.

    PubMed

    Amodio, Piero; Andrews, Paul; Salemme, Marinella; Ponte, Giovanna; Fiorito, Graziano

    2014-01-01

    The willingness of the cephalopod mollusc Octopus vulgaris to attack a live crab is traditionally used as a method to assess the overall health and welfare of octopuses in the laboratory. This method requires placing a crab in the home tank of an animal, measuring the time (latency) taken for the octopus to initiate an attack and withdrawing the crab immediately prior to capture. The same crab is commonly used to assess multiple octopuses as part of daily welfare assessment. Growing concern for the welfare of crustaceans and a review of all laboratory practices for the care and welfare of cephalopods following the inclusion of this taxon in 2010/63/EU prompted a study of the utility of an artificial crab to replace a live crab in the assessment of octopus health. On consecutive days O. vulgaris (N=21) were presented with a live, a dead or an artificial crab, and the latency to attack measured. Despite differences in the predatory performance towards the three different crab alternatives, octopuses readily attacked the artificial (and the dead) crab, showing that they can generalize and respond appropriately towards artificial prey. Researchers should consider using an artificial crab to replace the use of a live crab as part of the routine health assessment of O. vulgaris.

  1. The use of artificial crabs for testing predatory behavior and health in the octopus.

    PubMed

    Amodio, Piero; Andrews, Paul; Salemme, Marinella; Ponte, Giovanna; Fiorito, Graziano

    2014-01-01

    The willingness of the cephalopod mollusc Octopus vulgaris to attack a live crab is traditionally used as a method to assess the overall health and welfare of octopuses in the laboratory. This method requires placing a crab in the home tank of an animal, measuring the time (latency) taken for the octopus to initiate an attack and withdrawing the crab immediately prior to capture. The same crab is commonly used to assess multiple octopuses as part of daily welfare assessment. Growing concern for the welfare of crustaceans and a review of all laboratory practices for the care and welfare of cephalopods following the inclusion of this taxon in 2010/63/EU prompted a study of the utility of an artificial crab to replace a live crab in the assessment of octopus health. On consecutive days O. vulgaris (N=21) were presented with a live, a dead or an artificial crab, and the latency to attack measured. Despite differences in the predatory performance towards the three different crab alternatives, octopuses readily attacked the artificial (and the dead) crab, showing that they can generalize and respond appropriately towards artificial prey. Researchers should consider using an artificial crab to replace the use of a live crab as part of the routine health assessment of O. vulgaris. PMID:24919978

  2. Quantification of the indirect effects of scallop dredge fisheries on a brown crab fishery.

    PubMed

    Öndes, Fikret; Kaiser, Michel J; Murray, Lee G

    2016-08-01

    This study aimed to describe the characteristics of the by-catch of Cancer pagurus in king scallop dredges in the Isle of Man, and to determine the damage, immediate mortality and estimated mortality during fishing seasons associated with scallop dredges. Based on dredge surveys, spatial and seasonal variations were observed, with the highest number of crabs found off the west coast of the Isle of Man in the autumn when berried females crabs were most frequently caught. In general, female crabs comprised 84% of the catch. The damage levels of crabs was high with 45% of crabs recorded as crushed or dead or with severe damage, whilst 24% of crabs exhibited missing limbs. Estimates of the potential mortality associated with scallop dredging led to a lower and upper estimate of possible crab by-catch mortality of 15t and 24t respectively which represented 3.0-4.8% of the commercial landings of brown crab for the Isle of Man. Heaviest mortalities of crabs occurred in autumn to the west of the Isle of Man when female berried crabs move offshore into deeper water. The use of a temporary and spatially restricted scallop dredging closure could provide a simple solution to mitigate additional crab mortality in the event that scallop dredging increased beyond current levels in the future.

  3. The complete mitogenome of the hydrothermal vent crab Xenograpsus testudinatus (Decapoda, Brachyura) and comparison with brachyuran crabs.

    PubMed

    Ki, Jang-Seu; Dahms, Hans-Uwe; Hwang, Jiang-Shiou; Lee, Jae-Seong

    2009-12-01

    In this study, we analyzed the complete mitochondrial (mt) genome of a hydrothermal vent crab Xenograpsus testudinatus (Decapoda: Brachyura) obtained from the hydrothermal vents off Kueishantao Island, Taiwan, which extend from the deep sea Okinawa Trench. The mitogenome of X. testudinatus was 15,796 bp in length and contained the same 37 genes (e.g. 2 rRNAs, 22 tRNAs, and 13 PCGs) found in other metazoan mitogenomes. Analysis of the structural mt gene order in X. testudinatus revealed that the 13 PCGs, excluding a translocation of ND6-Cyt b cluster, were similarly ordered when compared to the pancrustacean ground pattern; however the tRNAs were severely rearranged. Phylogenetic analysis of decapod mitogenomes showed that the molecular taxonomy of the vent crab was in accordance with its morphological systematics. Together, these findings suggest that the vent crab studied here has little mitochondrial genetic variation when compared with morphologically defined conspecifics from other marine habitats.

  4. 50 CFR Table 8 to Part 680 - Initial QS and PQS Pool for Each Crab QS Fishery

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 200,000,000 PIK Pribilof Islands red and blue king crab 30,000,000 30,000,000 SMB St. Matthew blue... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Initial QS and PQS Pool for Each Crab QS... Crab QS Fishery Crab QS Fishery Initial QS Pool Initial PQS Pool BBR Bristol Bay red king crab...

  5. Symbiosis of sea anemones and hermit crabs: different resource utilization patterns in the Aegean Sea

    NASA Astrophysics Data System (ADS)

    Vafeiadou, Anna-Maria; Antoniadou, Chryssanthi; Chintiroglou, Chariton

    2012-09-01

    The small-scale distribution and resource utilization patterns of hermit crabs living in symbiosis with sea anemones were investigated in the Aegean Sea. Four hermit crab species, occupying shells of nine gastropod species, were found in symbiosis with the sea anemone Calliactis parasitica. Shell resource utilization patterns varied among hermit crabs, with Dardanus species utilizing a wide variety of shells. The size structure of hermit crab populations also affected shell resource utilization, with small-sized individuals inhabiting a larger variety of shells. Sea anemone utilization patterns varied both among hermit crab species and among residence shells, with larger crabs and shells hosting an increased abundance and biomass of C. parasitica. The examined biometric relationships suggested that small-sized crabs carry, proportionally to their weight, heavier shells and increased anemone biomass than larger ones. Exceptions to the above patterns are related either to local resource availability or to other environmental factors.

  6. Carriage of Clostridium perfringens by benthic crabs in a sewage-polluted estuary.

    PubMed

    La Sala, Luciano F; Redondo, Leandro M; Díaz Carrasco, Juan M; Pereyra, Ana María; Farber, Marisa; Jost, Helen; Fernández-Miyakawa, Mariano E

    2015-08-15

    The Estuary of Bahía Blanca (EBB), Argentina, is an important wetland under intense sewage pollution. We investigated the occurrence of Clostridium perfringens (CP) in populations of two benthic crabs (Neohelice granulata and Cyrtograpsus angulatus) and in sediment from the EBB. CP was found in 49.1% of the crabs and all of the isolates were identified as type A. The alpha (cpa) and enterotoxin (cpe) encoding genes were identified. Genetic analyses identified 13 novel sequence types, and found no clustering among isolates, suggesting that CP is not part of the crabs' commensal flora. CP carriage was 51 times more likely in crabs from the area nearest sewage outfalls compared with crabs from a reference site. Our in vitro experiments suggest that the carriage of CP in crabs is transient. The use of these benthic crabs as monitoring organisms of sewage pollution in coastal habitats is proposed.

  7. Contextual Pavlovian conditioning in the crab Chasmagnathus.

    PubMed

    Fustiñana, María Sol; Carbó Tano, Martín; Romano, Arturo; Pedreira, María Eugenia

    2013-03-01

    In contextual conditioning, a complex pattern of information is processed to associate the characteristics of a particular place with incentive or aversive reinforcements. This type of learning has been widely studied in mammals, but studies of other taxa are scarce. The context-signal memory (CSM) paradigm of the crab Chasmagnathus has been extensively used as a model of learning and memory. Although initially interpreted as habituation, some characteristics of contextual conditioning have been described. However, no anticipatory response has been detected for animals exposed to the training context. Thus, CSM could be interpreted either as an associative habituation or as contextual conditioning that occurs without a context-evoked anticipatory response. Here, we describe a training protocol developed for contextual Pavlovian conditioning (CPC). For each training trial, the context (conditioned stimulus, CS) was discretely presented and finished together with the unconditioned stimulus (US). In agreement with the CSM paradigm, a robust freezing response was acquired during the 15 training trials, and clear retention was found when tested with the US presentation after short (2 and 4 h) and long (1-4 days) delays. This CPC memory showed forward but not simultaneous presentation conditioning and was context specific and protein synthesis dependent. Additionally, a weak CPC memory was enhanced during consolidation. One day after training, CPC was extinguished by repeated CS presentation, while one presentation induced a memory labilisation-reconsolidation process. Finally, we found an anticipatory conditioned response (CR) during the CS presentation for both short-term (4 h) and long-term memory (24 h). These findings support the conditioning nature of the new paradigm.

  8. Ecology and behavior of Gecarcoidea natalis, the Christmas Island red crab, during the annual breeding migration.

    PubMed

    Adamczewsk, A M; Morris, S

    2001-06-01

    The terrestrial crab Gecarcoidea natalis is endemic to the forests of Christmas Island but must migrate each year to the coast to breed. During 1993 and 1995, radio-tracking, mark and recapture, and counting methods were used to establish the routes, walking speeds, direction of travel, and destinations of migrating crabs, as well as crab numbers and distribution. The density of crabs ranged from 0.09 to 0.57 crabs per square meter, which gave a population estimate of 43.7 million adult crabs on the island. During the dry season the crabs were relatively inactive but on arrival of the wet season immediately began their migration. The crabs generally walked in straight lines, and most crabs from around the Island traveled toward the northwest shore instead of simply walking toward the nearest shore. The maximum recorded distance walked by a red crab in one day was 1460 m, but the mean was 680 m per day in 1993 and 330 m in 1995. Comparing the 1993 and 1995 study seasons, there was a 3-week difference in the timing of the start of the migration, but the spawning date was fixed by the lunar phase and took place 17 to 18 days after mating. In 1993, late rain prompted a "rushed" migration and crabs walked directly to their shore destinations; in contrast, in 1995 most crabs made stops of 1 to 7 days during the downward migration. By giving the crabs a chance to feed along the way and minimizing the time that the population was concentrated near the shore, these stops may be important in ensuring that the animals have enough food after the long dry season. Furthermore, this behavior implies that the crabs are able to judge how far away they are from the shore during the migration.

  9. Effect of melatonin in the antioxidant defense system in the locomotor muscles of the estuarine crab Neohelice granulata (Decapoda, Brachyura).

    PubMed

    Geihs, Márcio Alberto; Vargas, Marcelo Alves; Maciel, Fábio Everton; Caldas, Sergiane Souza; Cruz, Bruno Pinto; Primel, Ednei Gilberto; Monserrat, José Maria; Nery, Luiz Eduardo Maia

    2010-03-01

    In vertebrates, many studies verified different effects of melatonin in the antioxidant defense system (ADS). In crustaceans, few studies have been conducted to verify this possibility. We verified the melatonin effects in the crab Neohelice granulata using low (0.002 and 0.02 pmol/crab) and high (2.0 and 20.0 pmol/crab) melatonin dosages in short-term (0.5h) and long-term (9.5h) experiments. We analyzed the antioxidant capacity against peroxyl radicals (ACAP), reactive oxygen species (ROS) concentration, levels of by products of lipid peroxidation (LPO), oxygen consumption (VO(2)), the activity of glutamate cysteine ligase (gamma-GCL) and catalase (CAT) and glutathione content (GSH). Finally, the effects of exogenous melatonin were verified in terms of melatonin and N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) content in the muscles of N. granulata. In short-term experiment and low dosages, melatonin increased the VO(2), gamma-GCL activity and GSH content (p<0.05) and decreased melatonin content (p<0.05) without effects in ROS, ACAP and LPO (p>0.05). Possibly, melatonin is acting in the ADS increasing its efficiency and/or acting in mitochondrial activity and/or through signaling muscles to increase its consumption. AFMK was only detected in the eyestalk and cerebroid ganglia. In high dosages melatonin effects decreased, possibly by the desensitization of their receptors. In long-term experiment, melatonin decreased ACAP (p<0.05), and CAT activity (p<0.05) in low dosages. In high dosages melatonin reduced VO(2) (p<0.05) and increased ACAP (p<0.05), possibly stimulating others components of the ADS. In conclusion, melatonin in the locomotor muscles of N. granulata affects the antioxidant/pro-oxidant balance in a time and dosage dependent manner.

  10. Computation of object approach by a system of visual motion-sensitive neurons in the crab Neohelice.

    PubMed

    Oliva, Damián; Tomsic, Daniel

    2014-09-15

    Similar to most visual animals, crabs perform proper avoidance responses to objects directly approaching them. The monostratified lobula giant neurons of type 1 (MLG1) of crabs constitute an ensemble of 14-16 bilateral pairs of motion-detecting neurons projecting from the lobula (third optic neuropile) to the midbrain, with receptive fields that are distributed over the extensive visual field of the animal's eye. Considering the crab Neohelice (previously Chasmagnathus) granulata, here we describe the response of these neurons to looming stimuli that simulate objects approaching the animal on a collision course. We found that the peak firing time of MLG1 acts as an angular threshold detector signaling, with a delay of δ = 35 ms, the time at which an object reaches a fixed angular threshold of 49°. Using in vivo intracellular recordings, we detected the existence of excitatory and inhibitory synaptic currents that shape the neural response. Other functional features identified in the MLG1 neurons were phasic responses at the beginning of the approach, a relation between the stimulus angular velocity and the excitation delay, and a mapping between membrane potential and firing frequency. Using this information, we propose a biophysical model of the mechanisms that regulate the encoding of looming stimuli. Furthermore, we found that the parameter encoded by the MLG1 firing frequency during the approach is the stimulus angular velocity. The proposed model fits the experimental results and predicts the neural response to a qualitatively different stimulus. Based on these and previous results, we propose that the MLG1 neuron system acts as a directional coding system for collision avoidance.

  11. Hard X-ray Variations in the Crab Nebula

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Cherry, M. L.; Case, G. L.; Baumgarter, W. H.; Beklen, E.; Bhat, P. N.; Briggs, M. S.; Camero-Arranz, A.; Chaplin, V.; Connaughton, V.; Finger, M. H.; Gehrels, N.; Greiner, J.; Jahoda, K.; Jenke, P.; Kippen, R. M.; Kouveliotou, C.; Krimm, H. A.; Kuulkers, E.; Lund, N.; Meegan, C. A.; Natalucci, L.; Paciesas, W. S.; Preece, R.; Rodi, J. C.

    2012-01-01

    In the first two years of science operations of the Fermi Gamma-ray Burst Monitor (GBM), August 2008 to August 2010, a approx.7% (70 mcrab) decline was discovered in the overall Crab Nebula flux in the 15 - 50 keV band, measured with the Earth occultation technique. This decline was independently confirmed with four other instruments: the RXTE/PCA, Swift/BAT, INTEGRAL/IBIS, and INTEGRAL/SPI. The pulsed flux measured with RXTE/PCA from 1999-2010 was consistent with the pulsar spin-down, indicating that the observed changes were nebular. From 2001 to 2010, the Crab nebula flux measured with RXTE/PCA was particularly variable, changing by up to approx.3.5% per year in the 15-50 keV band. These variations were confirmed with INTEGRAL/SPI starting in 2003, Swift/BAT starting in 2005, and Fermi GBM starting in 2008. Before 2001 and since 2010, the Crab nebula flux has appeared more stable, varying by less than 2% per year. I will present updated light curves in multiple energy bands for the Crab nebula, including recent data from Fermi GBM, Swift/BAT, and MAXI, and a 16-year long light curve from RXTE/PCA.

  12. Hard X-ray Variations in the Crab Nebula

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Cherry, M. L.; Case, G. L.; Baumgartner, W. H.; Beklen, E.; Bhat, P. N.; Briggs, M. S.; Camero-Arranz, A.; Chaplin, V.; Connaughton, V.; Finger, M. H.; Gehrels, N.; Greiner, J.; Jahoda, K.; Jenke, P.; Kippen, R. M.; Kouveliotou, C.; Krimm, H. A.; Kuulkers, E.; Meegan, C. A.; Natalucci, L.; Paciesas, W. S.; Preece, R.; Rodi, J. C.; Skinner, G. K.

    2013-01-01

    In the first two years of science operations of the Fermi Gamma-ray Burst Monitor (GBM), August 2008 to August 2010, approximately 7% (70 mcrab) decline was discovered in the overall Crab Nebula flux in the 15 - 50 keV band, measured with the Earth occultation technique. This decline was independently confirmed with four other instruments: the RXTE/PCA, Swift/BAT, INTEGRAL/IBIS, and INTEGRAL/SPI. The pulsed flux measured with RXTE/PCA from 1999-2010 was consistent with the pulsar spin-down, indicating that the observed changes were nebular. From 2001 to 2010, the Crab nebula flux measured with RXTE/PCA was particularly variable, changing by up to approximately 3.5% per year in the 15-50 keV band. These variations were confirmed with INTEGRAL/SPI starting in 2003, Swift/BAT starting in 2005, and Fermi GBM starting in 2008. Before 2001 and since 2010, the Crab nebula flux has appeared more stable, varying by less than 2% per year. I will present updated light curves in multiple energy bands for the Crab nebula, including recent data from Fermi GBM, Swift/BAT, INTEGRAL and MAXI, and a 16-year long light curve from RXTE/PCA.

  13. Hard X-ray Variations in the Crab Nebula

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Cherry, M. L.; Case, G. L.; Baumgartner, W. H.; Beklen, E.; Bhat, P. N.; Briggs, M. S.; Camero-Arranz, A.; Connaughton, V.; Finger, M. H.; Gehrels, N.; Greiner, J.; Jahoda, K.; Jenke, P.; Kippen, R. M.; Kouveliotou, C.; Krimm, H. A.; Kuulkers, E.; Meegan, C. A.; Natalucci, L.; Paciesas, W. S.; Preece, R.; Rodi, J. C.; Skinner, G. K.

    2013-01-01

    In the first two years of science operations of the Fermi Gamma-ray Burst Monitor (GBM), August 2008 to August 2010, approximately 7% (70 mcrab) decline was discovered in the overall Crab Nebula flux in the 15 - 50 keV band, measured with the Earth occultation technique. This decline was independently confirmed with four other instruments: the RXTE/PCA, Swift/BAT, INTEGRAL/IBIS, and INTEGRAL/SPI. The pulsed flux measured with RXTE/PCA from 1999-2010 was consistent with the pulsar spin-down, indicating that the observed changes were nebular. From 2001 to 2010, the Crab nebula flux measured with RXTE/ PCA was particularly variable, changing by up to approximately 3.5% per year in the 15-50 keV band. These variations were confirmed with INTEGRAL/SPI starting in 2003, Swift/BAT starting in 2005, and Fermi GBM starting in 2008. Before 2001 and since 2010, the Crab nebula flux has appeared more stable, varying by less than 2% per year. I will present updated light curves in multiple energy bands for the Crab Nebula, including recent data from Fermi GBM, Swift/BAT, INTEGRAL and MAXI, and a 16-year long light curve from RXTE/PCA.

  14. Aggression and Food Resource Competition between Sympatric Hermit Crab Species

    PubMed Central

    Tran, Mark V.; O’Grady, Matthew; Colborn, Jeremiah; Van Ness, Kimberly; Hill, Richard W.

    2014-01-01

    The vertical zonation patterns of intertidal organisms have been topics of interest to marine ecologists for many years, with interspecific food competition being implicated as a contributing factor to intertidal community organization. In this study, we used behavioral bioassays to examine the potential roles that interspecific aggression and food competition have on the structuring of intertidal hermit crab assemblages. We studied two ecologically similar, sympatric hermit crab species, Clibanarius digueti [1] and Paguristes perrieri [2], which occupy adjacent zones within the intertidal region of the Gulf of California. During the search phase of foraging, C. digueti showed higher frequencies of aggressive behaviors than P. perrieri. In competition assays, C. digueti gained increased access to food resources compared to P. perrieri. The results suggest that food competition may play an important role in structuring intertidal hermit crab assemblages, and that the zonation patterns of Gulf of California hermit crab species may be the result of geographical displacement by the dominant food competitor (C. digueti). PMID:24632897

  15. Breeding biology of the intertidal sand crab, Emerita (Decapoda: Anomura).

    PubMed

    Subramoniam, T; Gunamalai, V

    2003-01-01

    Emerita is a burrowing mole crab or sand crab, adapted to life in wave-washed sandy beaches of temperate and tropical seas. The reproductive biology of this anomuran crab presents several peculiarities, all contributing to its adaptation to this harsh environmental niche. We discuss the following aspects: 1) sex ratio and size at sexual maturity, 2) neoteny and protandric hermaphroditism, 3) mating behaviour and sperm transfer strategy, 4) synchronisation of moulting and reproduction, 5) environmental impact on reproductive cycle and egg production, 6) biochemistry of yolk utilisation and energetics, 7) larval development, dispersal and settlement and 8) the value of Emerita as indicator species. These aspects are discussed in the light of the life history pattern, comprising a sedentary adult and pelagic larval phases. The successful colonisation of the physically challenging habitat of the sandy beach by Emerita is attributable largely to reproductive strategy and the larval developmental and recruitment pattern. Sensitivity to changing environmental conditions, including pollution, make this intertidal crab an indicator species for monitoring anthropogenic impact. PMID:14601412

  16. Use of Terrestrial Hermit Crabs in the Study of Habituation

    ERIC Educational Resources Information Center

    Nolan, Laurence J.

    2004-01-01

    For small colleges, the use of invertebrates in undergraduate learning laboratory experiments may be a valuable alternative to the use of vertebrate species. This article describes a habituation experiment using terrestrial hermit crabs. All of the materials required are inexpensive and readily available. What makes this experiment unique is that…

  17. Flexibility of crab chemosensory sensilla enables flicking antennules to sniff.

    PubMed

    Waldrop, Lindsay D; Reidenbach, Matthew A; Koehl, M A R

    2015-10-01

    The first step in smelling is capture of odorant molecules from the surrounding fluid. We used lateral flagella of olfactory antennules of crabs Callinectes sapidus to study the physical process of odor capture by antennae bearing dense tufts of hair-like chemosensory sensilla (aesthetascs). Fluid flow around and through aesthetasc arrays on dynamically scaled models of lateral flagella of C. sapidus was measured by particle image velocimetry to determine how antennules sample the surrounding water when they flick. Models enabled separate evaluation of the effects of flicking speed, aesthetasc spacing, and antennule orientation. We found that crab antennules, like those of other malacostracan crustaceans, take a discrete water sample during each flick by having a rapid downstroke, during which water flows into the aesthetasc array, and a slow recovery stroke, when water is trapped in the array and odorants have time to diffuse to aesthetascs. However, unlike antennules of crustaceans with sparse aesthetasc arrays, crabs enhance sniffing via additional mechanisms: 1) Aesthetascs are flexible and splay as a result of the hydrodynamic drag during downstrokes, then clump together during return strokes; and 2) antennules flick with aesthetascs on the upstream side of the stalk during downstrokes, but are hidden downstream during return strokes. Aiming aesthetascs into ambient flow maintains sniffing. When gaps between aesthetascs are wide, changes in antennule speed are more effective at altering flow through the array than when gaps are narrow. Nonetheless, if crabs had fixed gap widths, their ability to take discrete samples of their odorant environment would be diminished.

  18. 50 CFR 253.30 - Crab IFQ loans.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 CFR Part 680, Table 8; and (4) Who, at the time of initial application, meets all other applicable... 50 Wildlife and Fisheries 11 2013-10-01 2013-10-01 false Crab IFQ loans. 253.30 Section 253.30..., DEPARTMENT OF COMMERCE AID TO FISHERIES FISHERIES ASSISTANCE PROGRAMS Fisheries Finance Program § 253.30...

  19. 50 CFR 253.30 - Crab IFQ loans.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 CFR Part 680, Table 8; and (4) Who, at the time of initial application, meets all other applicable... 50 Wildlife and Fisheries 11 2012-10-01 2012-10-01 false Crab IFQ loans. 253.30 Section 253.30..., DEPARTMENT OF COMMERCE AID TO FISHERIES FISHERIES ASSISTANCE PROGRAMS Fisheries Finance Program § 253.30...

  20. Damping of unwanted modes in SRF deflecting/crabbing cavities

    SciTech Connect

    Burt, Graeme; Wang, Haipeng

    2014-01-01

    As deflecting and crab cavities do not use the fundamental acceleration mode for their operation, the spectrum of unwanted modes is significantly different from that of accelerating cavities. The fundamental acceleration mode is now unwanted and can cause energy spread in the beam; in addition this mode frequency is often close to or lower than that of the deflecting mode, making it difficult to damp. This is made more complex in some of the compact crab cavities as there small beampipes often attenuate the fields very sharply. In addition in some crab cavities there can be an orthogonal transverse mode similar to the deflecting mode, known as the same order mode. The degeneracy of these modes must be split by polarising the cavity and if the polarisation is not large enough, dampers should be placed at either an electric or magnetic field null of the crabbing mode to effectively damp the unwanted polarisation. Various concepts for dealing with unwanted modes in various SRF deflecting cavities will be reviewed.

  1. Project "Flappy Crab": An Edu-Game for Music Learning

    ERIC Educational Resources Information Center

    Cardoso Gomes, Cristina Maria; Guerreiro Figueiredo, Mauro Jorge; Bidarra, José; Cardoso Gomes, José Duarte

    2014-01-01

    This paper discusses some possibilities of gamification and remixing process for music education. Analyses also the concepts of gamification, mashup, remix and presents its possible usage in education--music teaching--through the development of the project/educational game "Flappy Crab". The article begins with a brief introduction to…

  2. 50 CFR 253.30 - Crab IFQ loans.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 CFR part 680, Table 8; and (4) Who, at the time of initial application, meets all other applicable... 50 Wildlife and Fisheries 11 2014-10-01 2014-10-01 false Crab IFQ loans. 253.30 Section 253.30..., DEPARTMENT OF COMMERCE AID TO FISHERIES FISHERIES ASSISTANCE PROGRAMS Fisheries Finance Program § 253.30...

  3. Crab Nebula Variations in Hard X-rays

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.

    2012-01-01

    The Crab Nebula was surprisingly variable from 2001-2010, with less variability before 2001 and since mid-2010. We presented evidence for spectral softening from RXTE, Swift/BAT, and Fermi GBM during the mid-2008-2010 flux decline. We see no clear connections between the hard X-ray variations and the GeV flares

  4. Classroom Applications Using Limulus Polyphemus--The American Horseshoe Crab.

    ERIC Educational Resources Information Center

    Pearson, Frederick C., III; Weary, Marlys

    1981-01-01

    Provides examples of several classroom activities utilizing the American horseshoe crab (Limulus Polyphemus), including raising fertilized eggs, fertilizing eggs in vitro, and testing water samples. Includes background information on the natural history, life cycle, and breeding habits of this animal. (DS)

  5. Gamma radiation from the Crab and Vela pulsars

    NASA Technical Reports Server (NTRS)

    Kanbach, Gottfried

    1990-01-01

    The young pulsars in Crab and Vela were observed as very efficient emitters of high energy gamma radiation. While their radiation in the radio, optical, and x ray range was always known to differ considerably, the gamma ray emission on a superficial level appears quite similar: lightcurves with two narrow peaks, separated by 141 deg (Crab) and 153 deg (Vela) and photon energies in excess of 1 GeV with spectra that can be described by a power-law for Crab and a broken power-law for Vela. The detailed observations of these sources with the COS-B instrument, extending over nearly seven years, have revealed significant differences in the characteristics of the pulsars in the gamma-ray domain. Secular changes in the temporal (Crab) and spectral (Vela) properties above 50 MeV were found. These tantalizing signatures of the pulsar emission processes must now be explored in more detail and over a larger spectral range with the GRO (Gamma Ray Observatory) instruments in order to gain a deeper understanding of the physics of young neutron stars.

  6. Early drawings of Messier 1: pineapple or crab?

    NASA Astrophysics Data System (ADS)

    Dewhirst, D. W.

    1983-06-01

    Articles on the history of the Crab Nebula frequently reproduce an enigmatical drawing of it by Lord Rosse. This drawing was quickly repudiated by him and replaced by a more recognizable one which is less well known. Both drawings are discussed.

  7. A Toll-like receptor in horseshoe crabs.

    PubMed

    Inamori, Kei-ichiro; Ariki, Shigeru; Kawabata, Shun-ichiro

    2004-04-01

    Non-self-recognition of invading microbes relies on the pattern-recognition of pathogen-associated molecular patterns (PAMPs) derived from microbial cell-wall components. Insects and mammals conserve a signaling pathway of the innate immune system through cell-surface receptors called Tolls and Toll-like receptors (TLRs). Bacterial lipopolysaccharides (LPSs) are an important trigger of the horseshoe crab's innate immunity to infectious microorganisms. Horseshoe crabs' granular hemocytes respond specifically to LPS stimulation, inducing the secretion of various defense molecules from the granular hemocytes. Here, we show a cDNA which we named tToll, coding for a TLR identified from hemocytes of the horseshoe crab Tachypleus tridentatus. tToll is most closely related to Drosophila Toll in both domain architecture and overall length. Human TLRs have been suggested to contain numerous PAMP-binding insertions located in the leucine-rich repeats (LRRs) of their ectodomains. However, the LRRs of tToll contained no obvious PAMP-binding insertions. Furthermore, tToll was non-specifically expressed in horseshoe crab tissues. These observations suggest that tToll does not function as an LPS receptor on granular hemocytes.

  8. Three-Dimensional Concentration Measurements around Actively Tracking Blue Crabs

    NASA Astrophysics Data System (ADS)

    Dickman, B. D.; Jackson, J. L.; Weissburg, M. J.; Webster, D. R.

    2006-11-01

    Many aquatic arthropods locate food, suitable habitats, and mates solely through information extracted by chemical signals in their environment. Chemical plumes detected by larger animals are influenced by turbulence that creates an intermittent and unpredictable chemical stimulus environment. To link the stimulus pattern to behavior, we have developed a measurement system to quantify the instantaneous odor concentration surrounding a freely tracking blue crab through three-dimensional laser-induced fluorescence (3DLIF). A blue crab receives chemical stimulus at several locations, including the antennules near the mouth region and the distal tips of the legs and claws. Hence, three-dimensional measurements of the concentration field are required to link behavior to plume structure. During trials, crabs began their search 150 cm downstream of a source, and walking kinematics were recording simultaneously. The crabs were reversibly ``blindfolded'' during tracking to prevent aversive reactions to the intense laser light. Our experiments allow us to examine how hypothesized navigational cues, such as concentration bursts at the antennules and spatial asymmetry in concentration at the distributed chemosensory organs on the legs and claws, results in particular decisions during navigation.

  9. Aerobic response to exercise of the fastest land crab.

    PubMed

    Full, R J; Herreid, C F

    1983-04-01

    To view the aerobic response to exercise, the ghost crab Ocypode guadichaudii was run in a treadmill respirometer at three velocities (0.13, 0.19, and 0.28 km/h) while oxygen consumption (VO2) was monitored. A steady-state VO2 that increased linearly with velocity was attained. VO2 transient periods at the beginning and end of exercise were extremely rapid with half times from 50 to 150 s. The magnitude of oxygen deficit and debt were small and both showed increases with an increase in velocity. Oxygen debt was measured at each velocity after 4-, 10-, and 20-min exercise bouts. No change in the magnitude of oxygen debt was observed with respect to exercise duration. Maximal VO2 was 11.9 times the average resting VO2. Oxygen uptake kinetics have shown only very sluggish and reduced rates in five other more sedentary crab species previously tested. The aerobic response pattern observed in the present study is more comparable to that of exercising mammals and highly aerobic ectothermic vertebrates. This suggests that the ghost crab meets the energy demand of sustained exercise by aerobic ATP production in contrast to many other crab species.

  10. Space Movie Reveals Shocking Secrets Of The Crab Pulsa

    NASA Astrophysics Data System (ADS)

    2002-09-01

    Just when it seemed like the summer movie season had ended, two of NASA's Great Observatories have produced their own action movie. Multiple observations made over several months with NASA's Chandra X-ray Observatory and the Hubble Space Telescope captured the spectacle of matter and antimatter propelled to near the speed of light by the Crab pulsar, a rapidly rotating neutron star the size of Manhattan. "Through this movie, the Crab Nebula has come to life," said Jeff Hester of Arizona State University in Tempe, lead author of a paper in the September 20th issue of The Astrophysical Journal Letters. "We can see how this awesome cosmic generator actually works." The Crab was first observed by Chinese astronomers in 1054 A.D. and has since become one of the most studied objects in the sky. By combining the power of both Chandra and Hubble, the movie reveals features never seen in still images. By understanding the Crab, astronomers hope to unlock the secrets of how similar objects across the universe are powered. Crab Nebula Composite Image Crab Nebula Composite Image Bright wisps can be seen moving outward at half the speed of light to form an expanding ring that is visible in both X-ray and optical images. These wisps appear to originate from a shock wave that shows up as an inner X-ray ring. This ring consists of about two dozen knots that form, brighten and fade, jitter around, and occasionally undergo outbursts that give rise to expanding clouds of particles, but remain in roughly the same location. "These data leave little doubt that the inner X-ray ring is the location of the shock wave that turns the high-speed wind from the pulsar into extremely energetic particles," said Koji Mori of Penn State University in University Park, a coauthor of the paper. Another dramatic feature of the movie is a turbulent jet that lies perpendicular to the inner and outer rings. Violent internal motions are obvious, as is a slow motion outward into the surrounding nebula of

  11. ACT: Acting Out Central Theme.

    ERIC Educational Resources Information Center

    Kise, Joan Duff

    1982-01-01

    The author describes ACT (Acting Out Central Theme), a method for dealing with psychomotor, cognitive, and affective domains in slow readers. The ACT approach involves three sessions which focus on discussion of a theme such as friendship, presentaton of the theme as a skit, and assignment of topics to individual students. (SW)

  12. Spatial and temporal patterns of subtidal and intertidal crabs excursions

    NASA Astrophysics Data System (ADS)

    Silva, A. C. F.; Boaventura, D. M.; Thompson, R. C.; Hawkins, S. J.

    2014-01-01

    Highly mobile predators such as fish and crabs are known to migrate from the subtidal zone to forage in the intertidal zone at high-tide. The extent and variation of these habitat linking movements along the vertical shore gradient have not been examined before for several species simultaneously, hence not accounting for species interactions. Here, the foraging excursions of Carcinus maenas (L.), Necora puber (Linnaeus, 1767) and Cancer pagurus (Linnaeus, 1758) were assessed in a one-year mark-recapture study on two replicated rocky shores in southwest U.K. A comparison between the abundance of individuals present on the shore at high-tide with those present in refuges exposed at low-tide indicated considerable intertidal migration by all species, showing strong linkage between subtidal and intertidal habitats. Estimates of population size based on recapture of marked individuals indicated that an average of ~ 4000 individuals combined for the three crab species, can be present on the shore during one tidal cycle. There was also a high fidelity of individuals and species to particular shore levels. Underlying mechanisms for these spatial patterns such as prey availability and agonistic interactions are discussed. Survival rates were estimated using the Cormack-Jolly-Seber model from multi-recapture analysis and found to be considerably high with a minimum of 30% for all species. Growth rates were found to vary intraspecifically with size and between seasons. Understanding the temporal and spatial variations in predation pressure by crabs on rocky shores is dependent on knowing who, when and how many of these commercially important crab species depend on intertidal foraging. Previous studies have shown that the diet of these species is strongly based on intertidal prey including key species such as limpets; hence intertidal crab migration could be associated with considerable impacts on intertidal assemblages.

  13. Seasonal variability of antioxidant biomarkers in mud crabs (Scylla serrata).

    PubMed

    Paital, Biswaranjan; Chainy, G B N

    2013-01-01

    Studies on oxidative stress (OS) in crustacea are widely used as ecotoxicological indices to assess the environment risk produced by the impact of several stressor and pollutants. In the present study, effects of seasonality on OS physiology markers such as antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase), small antioxidant molecules (ascorbic acid and reduced glutathione), oxidative stress indices (lipid peroxidation, protein carbonylation and hydrogen peroxide) and total antioxidant capacity in hepatopancreas, gills and abdominal muscle of adult mud crab Scylla serrata, sampled from Chilika lagoon of India, were determined in winter, summer and rainy seasons. Results indicate that variations in enzymatic and non-enzymatic antioxidants with relation to season were not only tissue specific but also were gender specific. The levels of OS parameters were higher in hepatopancreas in comparison to gills and abdominal muscle of the crabs in all seasons. OS indices in tissues of the crabs were mainly higher in summer season when temperature and salinity of the lagoon were high with low oxygen content. Although OS was lower in winter season and moderate in rainy season in tissues of male crabs, it was higher in gills and hepatopancreas of females in rainy season. Correlation analyses between hydrological parameters of the lagoon (temperature, salinity and dissolved oxygen content) and OS physiology parameters in tissues of crabs suggest that abiotic factors influence the levels of antioxidant enzymes and, thereby the OS status in a tissue and sex specific manner. Collectively, the results of the present work suggest that further investigation is warranted before using OS parameters in S. serrata as biomarkers to monitor estuarine environment as these are influenced by gender, tissue and season.

  14. Behavioral evidence illuminating the visual abilities of the terrestrial Caribbean hermit crab Coenobita clypeatus.

    PubMed

    Ping, Xiaoge; Lee, Ji Sun; Garlick, Dennis; Jiang, Zhigang; Blaisdell, Aaron P

    2015-09-01

    Hermit crabs hide into shells when confronted with potential dangers, including images presented on a monitor. We do not know, however, what hermit crabs can see and how they perceive different objects. We examined the hiding response of the Caribbean hermit crab (Coenobita clypeatus) to various stimuli presented on a monitor in seven experiments to explore whether crabs could discriminate different properties of a threatening digital image, including color, brightness, contrast, shape and orientation. We found crabs responded differently to expanding circles presented in wavelengths of light corresponding to what humans see as red, blue, and green. "Blue" stimuli elicited the strongest hiding response (Experiments 1, 2, & 7). "Blue" was also more effective than a gray stimulus of similar brightness (Experiment 3). Hermit crabs were sensitive to the amount of contrast between a stimulus and its background rather than absolute brightness of the stimulus (Experiment 4). Moreover, we did not find evidence that crabs could discriminate orientation (Experiment 6), and mixed evidence that they could discriminate stimulus shape (Experiments 5 & 7). These results suggest that the Caribbean hermit crab is sensitive to color features, but not spatial features, of a threatening object presented on a computer screen. This is the first study to use the hiding response of the hermit crab to examine its visual ability, and demonstrates that the hiding response provides a useful behavioral approach with which to study learning and discrimination in the hermit crab. PMID:26051192

  15. Distribution and shell selection by two hermit crabs in different habitats on Egyptian Red Sea Coast

    NASA Astrophysics Data System (ADS)

    El-Kareem Ismail, Tarek Gad

    2010-05-01

    The present work aims to assess the spatial distribution, analyze shell utilization, shell fitness and determine the effect of coexistence of two hermit crabs Calcinus latens and Clibanarius signatus on used shell resources in various habitats on the Red Sea Coast. Also, to determine the choice of shells and investigate the shell species preference of C. latens and C. signatus in the laboratory. The hermit crabs C. latens and C. signatus were found to occupy shells of 39 gastropod species. The most commonly occupied gastropod shells are those belonging to genera Strombus, Nerita, Cerithium and Planaxis. The results showed that crab individuals utilized mainly the shell with elongate aperture. Laboratory experiments showed that two crab species preferred shells of Strombus followed by Cerithium and Nerita when offered shells of nearly similar size (optimal). Crab individuals showed a significant preference for optimal sized shells when given suboptimal shells as an alternative choice. Also, the hermit crabs avoid damaged shells when given a choice of optimal sized damaged shell and optimal sized intact one. In addition, two hermit crab species chose shells of smaller than optimal size when given a choice of damaged optimal sized shells and smaller intact ones. On the other hand, field observations showed that most crab individuals lived in adequate sized shells. The present data conclude that shell selection by hermit crabs C. latens and C. signatus depends mostly on shell internal volume, shell quality and shell aperture size than other factors, because they provide a maximum protection for hermit crabs.

  16. Estimated Entrainment of Dungeness Crab During Dredging For The Columbia River Channel Improvement Project

    SciTech Connect

    Pearson, Walter H.; Williams, Greg D.; Skalski, John R.

    2002-12-01

    The studies reported here focus on issues regarding the entrainment of Dungeness crab related to the proposed Columbia River Channel Improvement Project and provided direct measurements of crab entrainment rates at three locations (Desdomona Shoals, Upper Sands, and Miller Sands) from RM4 to RM24 during summer 2002. Entrainment rates for all age classes of crabs ranged from zero at Miller Sands to 0.224 crabs per cy at Desdemona Shoals in June 2002. The overall entrainment rate at Desdomona Shoals in September was 0.120 crabs per cy. A modified Dredge Impact Model (DIM) used the summer 2002 entrainment rates to project crab entrainment and adult equivalent loss and loss to the fishery for the Channel Improvement Project. To improve the projections, entrainment data from Flavel Bar is needed. The literature, analyses of salinity intrusion scenarios, and the summer 2002 site-specific data on entrainment and salinity all indicate that bottom salinity influences crab distribution and entrainment, especially at lower salinities. It is now clear from field measurements of entrainment rates and salinity during a period of low river flow (90-150 Kcfs) and high salinity intrusion that entrainment rates are zero where bottom salinity is less than 16 o/oo most of the time. Further, entrainment rates of 2+ and older crab fall with decreasing salinity in a clear and consistent manner. More elaboration of the crab distribution- salinity model, especially concerning salinity and the movements of 1+ crab, is needed.

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

    PubMed

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

    2012-04-01

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

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

    PubMed

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

    2012-04-01

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

  19. CRABS IN CRISIS:BIOGEOGRAPHIC DISTRIBUTIONS, ABUNDANCES, AND VULNERABILITIES TO CLIMATE CHANGE OF BRACHYURAN AND LITHODID CRABS FROM THE GULF OF CALIFORNIA TO THE BEAUFORT SEA

    EPA Science Inventory

    To predict the relative vulnerability of near-coastal species to climate change we analyzed the biogeographic and abundance patterns of the brachyuran or ‘True’ crabs (n=368) and lithodid or ‘King’ crabs (n=20) that are found in the twelve MEOW (“Mar...

  20. Effect of crab size and habitat type on the locomotory activity of juvenile shore crabs, Carcinus maenas

    NASA Astrophysics Data System (ADS)

    Almeida, Maria João; Flores, Augusto A. V.; Queiroga, Henrique

    2008-12-01

    Post-settlement processes are a major focus in the study of the dynamics of marine populations and communities. Post-settlement movement of juveniles is an important, but often ignored, process which affects local predator-prey and competitive interactions. We used benthic suction sampling and pitfall traps to examine density and locomotory activity of Carcinus maenas juveniles in different intertidal habitat types in the Rio Mira Estuary, Portugal, to better understand intra-specific interactions in a system where density-dependent processes are known to regulate population dynamics. As expected, significantly higher densities of juvenile shore crabs were found from bare mud compared to densely vegetated habitats. At the time of sampling, small and intermediate stages together outnumbered by far the larger juveniles. Conversely, larger crabs were much more frequent than smaller ones in traps. A locomotory index (LI), i.e. the ratio between crab catch in pitfall traps and their density within their moving range, is proposed as a measure of movement. LI analyses indicated that: (1) movement is an order of magnitude higher in large than small juveniles and much higher in sparse than dense vegetation cover; (2) activity of small juveniles is mostly crepuscular, regardless of vegetation cover; and (3) movement of large juveniles is very limited in dense Zostera patches, but very high in sparsely vegetated areas, during the day and night. These results suggest that small juveniles are relatively protected under dense vegetation cover due to lower mobility of larger crabs, and provide evidence of temporal segregation of activity windows between juvenile crabs of different sizes, which may be a key mechanism to reduce cannibalism and therefore increase the carrying capacity of nursery habitats.

  1. Flocking and feeding in the fiddler crab ( UCA tangeri): Prey availability as risk-taking behaviour

    NASA Astrophysics Data System (ADS)

    Ens, B. J.; Klaassen, M.; Zwarts, L.

    For a full understanding of prey availability, it is necessary to study risk-taking behaviour of the prey. Fiddler crabs are ideally suited for such a study, as they have to leave their safe burrow to feed on the surface of the intertidal flats during low tide, thereby exposing themselves to avian predators. A study in an intertidal area along the coast of Mauritania showed that small crabs always stayed in the vicinity of their burrow, but large crabs wandered in large flocks (also referred to as droves) to feed on sea-grass beds downshore. Transplanting downshore feeding substrate to the burrowing zone of the small crabs proved that they too preferred to feed on it. Since small crabs can be preyed upon by more species of birds, this suggests that the decision not to leave the burrowing zone might be related to the risk of being fed upon by birds. We calculated predation risk from measurements on the density and feeding activity of the crabs, as well as the feeding density, the intake rate and the size selection of the avian predators. Per hour on the surface, crabs in a flock were more at risk than crabs feeding near their burrow. Thus, though flocking crabs may have benefited from 'swamping the predator' by emerging in maximum numbers during some tides only, this did not reduce their risk of predation below that of non-flocking crabs. Furthermore we found that irrespective of activity, large crabs suffered a higher mortality per tide from avian predators than small crabs. This suggests that large crabs could not sufficiently reduce their foraging time to compensate for the increased risk while foraging in a flock, even though they probably experienced better feeding conditions than small crabs staying near their burrow. The greater energy demands of large crabs were reflected in a greater surface area grazed. Thus, with increasing size a fiddler crab has to feed further away from its burrow and so may derive less protection from staying near to it. It seems that

  2. Toxicity of the dispersant Corexit 9500 to early life stages of blue crab, Callinectes sapidus.

    PubMed

    Anderson Lively, Julie A; McKenzie, Jon

    2014-12-01

    The Deepwater Horizon well released 4.4 million barrels of light crude oil offshore of Louisiana into one of the world's largest and most productive blue crab (Callinectes sapidus) fisheries. The objectives of this paper were to determine the toxicity of the dispersant Corexit(®) 9500A used in the 2010 oil spill on juvenile and larval blue crabs, and the long-term effects of sublethal acute exposure. Only the highest treatment levels of dispersant significantly increased mortality in larval and juvenile blue crabs (100 mg/L and 1,000 mg/L, respectively). This correlated to concentrations well above levels found in the Gulf of Mexico following the spill. Smaller and younger crabs showed higher mortality than older and larger crabs. This research indicates direct application of dispersants on crab larvae could cause acute mortality, but dilution through diffusion and natural weathering processes would minimize long-term effects. PMID:25173366

  3. Heavy metals in red crabs, Chaceon quinquedens, from the Gulf of Mexico.

    PubMed

    Perry, Harriet; Isphording, Wayne; Trigg, Christine; Riedel, Ralf

    2015-12-30

    The red crab, Chaceon quinquedens, is distributed in deep waters of the Gulf of Mexico (GOM) and is most abundant in an area associated with sediment deposition from the Mississippi River. Sediment geochemistry and biological and ecological traits of red crabs favor accumulation of contaminants. Red crabs, sediment, and bottom water samples were taken from three distinct geographic locations representing areas with differing exposure to contaminant laden effluents from the Mississippi River. Inductively coupled plasma spectrophotometry and atomic absorption spectrophotometry were employed to determine levels of heavy metals in red crab muscle tissue. Ion site partitioning was used to determine metal speciation in sediments. Red crabs showed evidence of heavy metal bioaccumulation in all sample areas with high variability in contaminant levels in individual crabs for some metals. Bioavailability of metals in sediment did not always result in accumulation in muscle tissue. PMID:26589640

  4. Metals in horseshoe crab eggs from Delaware Bay, USA: temporal patterns from 1993 to 2012.

    PubMed

    Burger, Joanna; Tsipoura, Nellie

    2014-10-01

    The health of horseshoe crab (Limulus polyphemus) eggs is important not only to maintain horseshoe crab populations, but because they are a resource for higher trophic levels, such as fish and shorebirds. We examined the concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the eggs of horseshoe crabs from Delaware Bay (between New Jersey and Delaware, USA) in 1993, 1994, 1995, 1999, 2000, and 2012 to determine if there were significant temporal changes and if levels appear to pose a health risk to the crabs themselves, or to predators that consume them. All metal levels declined in horseshoe crab eggs between 1994 and 2012, although the declines were much less consistent for lead and chromium than that for mercury and cadmium. Levels of contaminants found in these eggs are well below those known to cause adverse effects in the crabs themselves or to organisms that consume them, such as migrating shorebirds.

  5. Metals in horseshoe crab eggs from Delaware Bay, USA: temporal patterns from 1993 to 2012.

    PubMed

    Burger, Joanna; Tsipoura, Nellie

    2014-10-01

    The health of horseshoe crab (Limulus polyphemus) eggs is important not only to maintain horseshoe crab populations, but because they are a resource for higher trophic levels, such as fish and shorebirds. We examined the concentrations of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the eggs of horseshoe crabs from Delaware Bay (between New Jersey and Delaware, USA) in 1993, 1994, 1995, 1999, 2000, and 2012 to determine if there were significant temporal changes and if levels appear to pose a health risk to the crabs themselves, or to predators that consume them. All metal levels declined in horseshoe crab eggs between 1994 and 2012, although the declines were much less consistent for lead and chromium than that for mercury and cadmium. Levels of contaminants found in these eggs are well below those known to cause adverse effects in the crabs themselves or to organisms that consume them, such as migrating shorebirds. PMID:25015345

  6. Heavy metals in red crabs, Chaceon quinquedens, from the Gulf of Mexico.

    PubMed

    Perry, Harriet; Isphording, Wayne; Trigg, Christine; Riedel, Ralf

    2015-12-30

    The red crab, Chaceon quinquedens, is distributed in deep waters of the Gulf of Mexico (GOM) and is most abundant in an area associated with sediment deposition from the Mississippi River. Sediment geochemistry and biological and ecological traits of red crabs favor accumulation of contaminants. Red crabs, sediment, and bottom water samples were taken from three distinct geographic locations representing areas with differing exposure to contaminant laden effluents from the Mississippi River. Inductively coupled plasma spectrophotometry and atomic absorption spectrophotometry were employed to determine levels of heavy metals in red crab muscle tissue. Ion site partitioning was used to determine metal speciation in sediments. Red crabs showed evidence of heavy metal bioaccumulation in all sample areas with high variability in contaminant levels in individual crabs for some metals. Bioavailability of metals in sediment did not always result in accumulation in muscle tissue.

  7. Toxicity of the dispersant Corexit 9500 to early life stages of blue crab, Callinectes sapidus.

    PubMed

    Anderson Lively, Julie A; McKenzie, Jon

    2014-12-01

    The Deepwater Horizon well released 4.4 million barrels of light crude oil offshore of Louisiana into one of the world's largest and most productive blue crab (Callinectes sapidus) fisheries. The objectives of this paper were to determine the toxicity of the dispersant Corexit(®) 9500A used in the 2010 oil spill on juvenile and larval blue crabs, and the long-term effects of sublethal acute exposure. Only the highest treatment levels of dispersant significantly increased mortality in larval and juvenile blue crabs (100 mg/L and 1,000 mg/L, respectively). This correlated to concentrations well above levels found in the Gulf of Mexico following the spill. Smaller and younger crabs showed higher mortality than older and larger crabs. This research indicates direct application of dispersants on crab larvae could cause acute mortality, but dilution through diffusion and natural weathering processes would minimize long-term effects.

  8. The relationship of blue crab abundance to winter mortality of Whooping Cranes

    USGS Publications Warehouse

    Pugesek, Bruce H.; Baldwin, Michael J.; Stehn, Thomas

    2013-01-01

    We sampled blue crab (Callinectes sapidus) numbers in marshes on the Aransas National Wildlife Refuge, Texas from 1998-2006, while simultaneously censusing the wintering population of Whooping Cranes (Grus americana) on the refuge and surrounding habitats. This was done to determine whether mortality of wintering Whooping Cranes was related to the availability of this food source. Yearly variation in crab numbers was high, ranging from a low of 0.1 crabs to a high of 3.4 crabs per 100-m transect section. Significant non-linear increases in both juvenile and adult mortality in relation to decreasing crab abundance was observed. Results suggest that some threshold of crab abundance exists in which Whooping Cranes have higher survival on their wintering grounds.

  9. Disease, parasite, and commensal prevalences for blue crab Callinectes sapidus at shedding facilities in Louisiana, USA.

    PubMed

    Rogers, Holly A; Taylor, Sabrina S; Hawke, John P; Schott, Eric J; Anderson Lively, Julie A

    2015-01-15

    Blue crab diseases, parasites, and commensals are not well studied in the Gulf of Mexico, and their prevalence rates have only been sporadically determined. Commercial soft shell shedding facilities in Louisiana experience high mortality rates of pre-molt crabs, and some of these deaths may be attributable to diseases or parasites. During the active shedding season in 2013, we determined the prevalence of shell disease, Vibrio spp., Lagenophrys callinectes, and Hematodinium perezi at 4 commercial shedding facilities along the Louisiana coast. We also detected Ameson michaelis and reo-like virus infections. Shell disease was moderately prevalent at rates above 50% and varied by shedding facility, collection month, and crab size. Vibrio spp. bacteria were prevalent in the hemolymph of 37% of the pre-molt crabs. Lagenophrys callinectes was highly prevalent in the pre-molt crabs, but because it is a commensal species, it may not cause high mortality rates. Hematodinium perezi was absent in all pre-molt crabs.

  10. VARIABLE GAMMA-RAY EMISSION FROM THE CRAB NEBULA: SHORT FLARES AND LONG 'WAVES'

    SciTech Connect

    Striani, E.; Tavani, M.; Vittorini, V.; Donnarumma, I.; Argan, A.; Cardillo, M.; Costa, E.; Del Monte, E.; Pacciani, L.; Piano, G.; Sabatini, S.; Bulgarelli, A.; Ferrari, A.; Pellizzoni, A.; Pittori, C.; and others

    2013-03-01

    Gamma-ray emission from the Crab Nebula has been recently shown to be unsteady. In this paper, we study the flux and spectral variability of the Crab above 100 MeV on different timescales ranging from days to weeks. In addition to the four main intense and day-long flares detected by AGILE and Fermi-LAT between 2007 September and 2012 September, we find evidence for week-long and less intense episodes of enhanced gamma-ray emission that we call 'waves'. Statistically significant 'waves' show timescales of 1-2 weeks, and can occur by themselves or in association with shorter flares. We present a refined flux and spectral analysis of the 2007 September-October gamma-ray enhancement episode detected by AGILE that shows both 'wave' and flaring behavior. We extend our analysis to the publicly available Fermi-LAT data set and show that several additional 'wave' episodes can be identified. We discuss the spectral properties of the 2007 September 'wave'/flare event and show that the physical properties of the 'waves' are intermediate between steady and flaring states. Plasma instabilities inducing 'waves' appear to involve spatial distances l {approx} 10{sup 16} cm and enhanced magnetic fields B {approx} (0.5-1) mG. Day-long flares are characterized by smaller distances and larger local magnetic fields. Typically, the deduced total energy associated with the 'wave' phenomenon (E{sub w} {approx} 10{sup 42} erg, where E{sub w} is the kinetic energy of the emitting particles) is comparable with that associated to the flares, and can reach a few percent of the total available pulsar spin-down energy. Most likely, flares and waves are the product of the same class of plasma instabilities that we show acting on different timescales and radiation intensities.

  11. Juggling Act

    ERIC Educational Resources Information Center

    Rudalevige, Andrew

    2009-01-01

    Two education bills from George W. Bush's first term are long overdue for reauthorization. One, of course, is the No Child Left Behind Act (NCLB), passed in late 2001. The other is the Education Sciences Reform Act (ESRA), which in November 2002 replaced the Office of Educational Research and Improvement (OERI) with a new Institute of Education…

  12. Gamma radiation from the Crab nebula above 35 MeV

    NASA Technical Reports Server (NTRS)

    Kniffen, D. A.; Hartman, R. C.; Thompson, D. J.; Bignami, G. F.; Fichtel, C. E.; Oegelman, H.; Tuemer, T.

    1974-01-01

    Electromagnetic radiation from the Crab nebula were observed, showing that the Crab is unique among strong X-ray sources in that major component in the low energy range (1 to 10 KeV) shows little or no temporal variation. Observations of the Crab above 35 MeV were made with the high energy gamma ray telescope flown on SAS-2. The detector and technique are described in detail.

  13. Estimating Dungeness crab (Cancer magister) abundance: Crab pots and dive transects compared

    USGS Publications Warehouse

    Taggart, S.J.; O'Clair, C. E.; Shirley, T.C.; Mondragon, J.

    2004-01-01

    Dungeness crabs (Cancer magister) were sampled with commercial pots and counted by scuba divers on benthic transects at eight sites near Glacier Bay, Alaska. Catch per unit of effort (CPUE) from pots was compared to the density estimates from dives to evaluate the bias and power of the two techniques. Yearly sampling was conducted in two seasons: April and September, from 1992 to 2000. Male CPUE estimates from pots were significantly lower in April than in the following September; a step-wise regression demonstrated that season accounted for more of the variation in male CPUE than did temperature. In both April and September, pot sampling was significantly biased against females. When females were categorized as ovigerous and nonovigerous, it was clear that ovigerous females accounted for the majority of the bias because pots were not biased against nonovigerous females. We compared the power of pots and dive transects in detecting trends in populations and found that pots had much higher power than dive transects. Despite their low power, the dive transects were very useful for detecting bias in our pot sampling and in identifying the optimal times of year to sample so that pot bias could be avoided.

  14. Spatial patterns and movements of red king and Tanner crabs: Implications for the design of marine protected areas

    USGS Publications Warehouse

    Taggart, S.J.; Mondragon, J.; Andrews, A.G.; Nielsen, J.K.

    2008-01-01

    Most examples of positive population responses to marine protected areas (MPAs) have been documented for tropical reef species with very small home ranges; the utility of MPAs for commercially harvested temperate species that have large movement patterns remains poorly tested. We measured the distribution and abundance of red king Paralithodes camtschaticus and Tanner Chionoecetes bairdi crabs inside and outside of MPAs in Glacier Bay National Park, Alaska, USA. By tagging a sub-sample of crabs with sonic tags, we estimated the movement of adult crabs from one of the MPAs (Muir Inlet) into the central portion of Glacier Bay where fishing still occurs. Tanner crabs and red king crabs moved similar average distances per day, although Tanner crabs had a higher transfer out of the Muir Inlet MPA into the central bay. Tanner crab movements were characterized by large variation among individual crabs, both in distance and direction traveled, while red king crabs migrated seasonally between 2 specific areas. Although Tanner crabs exhibited relatively large movements, distribution and abundance data suggest that they may be restricted at large spatial scales by habitat barriers. MPAs that are effective at protecting king and especially Tanner crab brood stock from fishing mortality will likely need to be larger than is typical of MPAs worldwide. However, by incorporating information on the seasonal movements of red king crabs and the location of habitat barriers for Tanner crabs, MPAs could likely be designed that would effectively protect adults from fishing mortality. ?? Inter-Research 2008.

  15. Multipole Field Effects for the Superconducting Parallel-Bar Deflecting/Crabbing Cavities

    SciTech Connect

    De Silva, Payagalage Subashini Uddika; Delayen, Jean Roger

    2012-09-01

    The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

  16. Crabs Mediate Interactions between Native and Invasive Salt Marsh Plants: A Mesocosm Study

    PubMed Central

    Zhang, Xiao-dong; Jia, Xin; Chen, Yang-yun; Shao, Jun-jiong; Wu, Xin-ru; Shang, Lei; Li, Bo

    2013-01-01

    Soil disturbance has been widely recognized as an important factor influencing the structure and dynamics of plant communities. Although soil reworkers were shown to increase habitat complexity and raise the risk of plant invasion, their role in regulating the interactions between native and invasive species remains unclear. We proposed that crab activities, via improving soil nitrogen availability, may indirectly affect the interactions between invasive Spartina alterniflora and native Phragmites australis and Scirpus mariqueter in salt marsh ecosystems. We conducted a two-year mesocosm experiment consisting of five species combinations, i.e., monocultures of three species and pair-wise mixtures of invasive and native species, with crabs being either present or absent for each combination. We found that crabs could mitigate soil nitrogen depletion in the mesocosm over the two years. Plant performance of all species, at both the ramet-level (height and biomass per ramet) and plot-level (density, total above- and belowground biomass), were promoted by crab activities. These plants responded to crab disturbance primarily by clonal propagation, as plot-level performance was more sensitive to crabs than ramet-level. Moreover, crab activities altered the competition between Spartina and native plants in favor of the former, since Spartina was more promoted than native plants by crab activities. Our results suggested that crab activities may increase the competition ability of Spartina over native Phragmites and Scirpus through alleviating soil nitrogen limitation. PMID:24023926

  17. Oxygen and carbon dioxide sensitivity of ventilation in amphibious crabs, Cardisoma guanhumi, breathing air and water.

    PubMed

    Gannon, Andrew T; Henry, Raymond P

    2004-05-01

    Amphibious crabs, Cardisoma guanhumi, were acclimated to breathing either air or water and exposed to altered levels of oxygen and/or carbon dioxide in the medium. Hypercapnia (22, 36 and 73 torr CO(2)) stimulated a significant hypercapnic ventilatory response (HCVR) in both groups of crabs, with a much greater effect on scaphognathite frequency (Deltaf(SC)=+700%) in air-breathing crabs than water-breathing crabs (Deltaf(SC)=+100%). In contrast, hyperoxia induced significant hypoventilation in both sets of crabs. However, simultaneous hyperoxia and hypercapnia triggered a greater than 10-fold increase in f(SC) in air-breathing crabs but no change in water-breathing crabs. For water-breathing crabs hypoxia simultaneous with hypercapnia triggered the same response as hypoxia alone-bradycardia (-50%), and a significant increase in f(SC) at moderate exposures but not at the more extreme levels. The response of air-breathing crabs to hypoxia concurrent with hypercapnia was proportionally closer to the response to hypercapnia alone than to hypoxia. Thus, C. guanhumi were more sensitive to ambient CO(2) than O(2) when breathing air, characteristic of fully terrestrial species, and more sensitive to ambient O(2) when breathing water, characteristic of fully aquatic species. C. guanhumi possesses both an O(2)- and a CO(2)-based ventilatory drive whether breathing air or water, but the relative importance switches when the respiratory medium is altered.

  18. The effect of salinity on experimental infections of a Hematodinium sp. in blue crabs, Callinectes sapidus.

    PubMed

    Coffey, Anna H; Li, Caiwen; Shields, Jeffrey D

    2012-06-01

    The parasitic dinoflagellate Hematodinium sp. parasitizes blue crabs along the Atlantic seaboard of the United States. Infections in blue crabs have only been reported from waters where salinity is >11 practical salinity units (psu). Blue crabs maintain a hyperosmotic internal concentration at low salinities (0-5 psu), roughly comparable to 24 psu, and should be capable of maintaining an infection in low-salinity waters even if Hematodinium spp. cells are intolerant of low salinities. We tested this notion by observing the effect of low salinity on the progression of disease in crabs experimentally infected with the parasite. Blue crabs were acclimated to 5 psu or 30 psu salinity treatments. They were inoculated with Hematodinium sp. and necropsied 3, 7, 10, and 15 days post-inoculation. The low-salinity treatment did not have an effect on the proliferation of Hematodinium sp. infections in blue crabs; moreover, a greater proportion of infections in crabs in the low-salinity treatment developed dinospore stages than did those in the high-salinity treatment, indicating that salinity may affect the development of the parasite. However, dinospores from in vitro cultures rapidly became inactive when held in salinities <15 psu. Our experiments indicate that Hematodinium spp. can develop in blue crabs at low salinities, but that the parasite is incapable of transmission in this environment, which explains the lack of natural infections in crabs at low salinities.

  19. Edible crabs "go west": migrations and incubation cycle of Cancer pagurus revealed by electronic tags.

    PubMed

    Hunter, Ewan; Eaton, Derek; Stewart, Christie; Lawler, Andrew; Smith, Michael T

    2013-01-01

    Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs' behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means.

  20. Diet selectivity of juvenile blue crabs (Callinectes sapidus) in Chesapeake Bay.

    PubMed

    Seitz, Rochelle D; Knick, Kathleen E; Westphal, Miranda

    2011-10-01

    Shallow coves in Chesapeake Bay have abundant food and serve as nursery grounds for juvenile blue crabs. In this study, we examined the relationships between the diet of very small (4-40 mm CW) juvenile blue crabs and the benthic infauna in shallow, unvegetated nursery coves. We compared infauna in benthic samples with gut contents of juvenile blue crabs from six shallow coves in each of two sub-estuaries (Rappahannock and York Rivers) in Chesapeake Bay, Virginia, USA. Benthic communities differed depending on river and location, with abundant clams in upriver regions and abundant polychaetes in downriver regions. Juvenile crabs, like adults, appeared to be opportunistic feeders, with gut contents including clams, amphipods, polychaetes, small crustaceans, plant matter, and detritus. There was a positive relationship between polychaetes in the benthic samples and in crab guts, suggesting that juvenile crabs are opportunistic feeders on polychaetes in the benthos. Moreover, Ivlev's electivity index and foraging ratio showed that clams and polychaetes were selectively eaten at all locations. Alternatively, crabs selectively rejected amphipods. Crab densities corresponded positively with polychaete densities, which suggests that there may be bottom-up control of crab distributions and that food resources are important in nursery habitats.

  1. Incidence of Vibrio species associated with blue crabs (Callinectes sapidus) collected from Galveston Bay, Texas.

    PubMed Central

    Davis, J W; Sizemore, R K

    1982-01-01

    Bacteria were readily isolated from the hemolymph of a majority (88%) of the blue crabs collected from Galveston Bay, Texas. The hemolymph of most crabs contained moderate (greater than 10(3) bacteria/ml) to heavy (greater than (10(5) bacteria/ml) infections. Large variances were observed in the bacterial number associated with individual crabs, but no significant difference was observed between the mean bacterial levels in the hemolymph of crabs collected during different seasons of the sampling year. Vibrio spp. were the predominant bacterial types in the hemolymph of infected crabs and increased in number significantly during the summer season. Warmer water temperatures were thought to be responsible for this increase. Bacterial numbers and the percentage of Vibrio spp. were highest in the interior of the crab bodies, especially in the digestive tract. The exterior of the crabs did not appear to be the source of the hemolymph's bacterial flora. Bacteria taxonomically identical to Vibrio cholerae. V. vulnificus, and V. parahaemolyticus were routinely isolated from the crab hemolymph and external carapace. V. parahaemolyticus was the most prevalent of the pathogenic Vibrio spp. and was isolated from 23% of the hemolymph samples. V. vulnificus (7%) and V. cholerae (2%) occurred less commonly in the hemolymph. The incidences of V. parachaemolyticus and V. vulnificus were related and increased in the summer months. Both organisms were frequently isolated from the same crab. PMID:7103475

  2. Hermit crabs in the diet of Pigeon Guillemots at Kachemak Bay, Alaska

    USGS Publications Warehouse

    Litzow, M.A.; Piatt, J.F.; Figurski, J.D.

    1998-01-01

    Guillemots (Cepphus spp.) feed their chicks a diet that is almost exclusively fish. We observed Pigeon Guillemots (C. columba) at two colonies in Alaska where hermit crabs (Crustacea: Anomura) were a major part of the diet for some nestlings. Hermit crabs were delivered to three of five observed nests at one colony, comprised between 2% and 22% of the items delivered at those nests, and were the second most common food type at one nest. Hermit crabs may be an attractive prey item when lipid-rich forage fish are scarce, and crabs living in gastropod shells that have been softened by encrustations of Suberiles sponges may be vulnerable to guillemot predation.

  3. Zoothamnium duplicatum infestation of cultured horseshoe crabs (Limulus polyphemus).

    PubMed

    Shinn, Andrew P; Mühlhölzl, Alexander P; Coates, Christopher J; Metochis, Christoforos; Freeman, Mark A

    2015-02-01

    An outbreak of the sessile peritrich Zoothamnium duplicatum in a pilot, commercial-scale Limulus polyphemus hatchery resulted in the loss of ∼96% (40,000) second/third instar larvae over a 61day period. peritrich growth was heavy, leading to mechanical obstruction of the gills and physical damage. The peritrichs were controlled without resultant loss of juvenile crabs by administering 10ppm chlorine in freshwater for 1h and the addition of aquarium grade sand; a medium into which the crabs could burrow and facilitate cleaning of the carapace. Peritrich identity was confirmed from a partial SSU rDNA contiguous sequence of 1343bp (99.7% similarity to Z. duplicatum). PMID:25499897

  4. SHORT-LIVED RADIO BURSTS FROM THE CRAB PULSAR

    SciTech Connect

    Crossley, J. H.; Eilek, J. A.; Hankins, T. H.; Kern, J. S.

    2010-10-20

    Our high-time-resolution observations reveal that individual main pulses from the Crab pulsar contain one or more short-lived microbursts. Both the energy and duration of bursts measured above 1 GHz can vary dramatically in less than a millisecond. These fluctuations are too rapid to be caused by propagation through turbulence in the Crab Nebula or in the interstellar medium; they must be intrinsic to the radio emission process in the pulsar. The mean duration of a burst varies with frequency as {nu}{sup -2}, significantly different from the broadening caused by interstellar scattering. We compare the properties of the bursts to some simple models of microstructure in the radio emission region.

  5. THE CRAB PULSAR AT CENTIMETER WAVELENGTHS. I. ENSEMBLE CHARACTERISTICS

    SciTech Connect

    Hankins, T. H.; Eilek, J. A.; Jones, G.

    2015-04-01

    We have observed the pulsar in the Crab Nebula at high radio frequencies and high time resolution. We present continuously sampled data at 640 ns time resolution and individual bright pulses recorded at down to 0.25 ns time resolution. Combining our new data with previous data from our group and from the literature shows the dramatic changes in the pulsar’s radio emission between low and high radio frequencies. Below about 5 GHz the mean profile is dominated by the bright Main Pulse and Low-Frequency Interpulse. Everything changes, however, above about 5 GHz; the Main Pulse disappears and the mean profile of the Crab pulsar is dominated by the High-Frequency Interpulse (which is quite different from its low-frequency counterpart) and the two High-Frequency Components. We present detailed observational characteristics of these different components which future models of the pulsar’s magnetosphere must explain.

  6. Cryptic invasions of the crab Carcinus detected by molecular phylogeography.

    PubMed

    Geller, J B; Walton, E D; Grosholz, E D; Ruiz, G M

    1997-10-01

    Coastal marine ecosystems world-wide are threatened by invasions of nonindigenous species. The ubiquity of marine sibling species identifiable only by genetic analysis suggests that many invasions are cryptic and therefore undetected, causing an underestimation of the actual number and impacts of invading species. We test this hypothesis with European crabs in the genus Carcinus that have invaded five regions globally. Partial 16S ribosomal RNA gene sequences confirm sibling species status of morphologically similar Atlantic C. maenas and Mediterranean C. aestuarii. Based on 16S rRNA haplotypes, crabs from California, New England and Tasmania were all C. maenas. However, we report the cryptic multiple invasion of both species in Japan and South Africa, where only C. aestuarii and C. maenas, respectively, were previously recognized. PMID:9348700

  7. Feeding Behavior of a Crab According to Cheliped Number.

    PubMed

    de Oliveira, Diogo Nunes; Christofoletti, Ronaldo Adriano; Barreto, Rodrigo Egydio

    2015-01-01

    Cheliped loss through autotomy is a common reflexive response in decapod crustaceans. Cheliped loss has direct and indirect effects on feeding behavior which can affect population dynamics and the role of species in the community. In this study, we assessed the impact of autotomy (0, 1, or 2 cheliped loss) on feeding behavior in the crab Pachygrapsus transversus, an omnivorous and abundant species that inhabits subtropical intertidal rocky shores along the South Atlantic Ocean. Autotomy altered crab feeding patterns and foraging behavior; however, the time spent foraging on animal prey or algae was not affected. These results indicate a plasticity of feeding behavior in P. transversus, allowing them to maintain feeding when injured. PMID:26682546

  8. Lipids from nerve tissues of the horseshoe crab, Limulus polyphemus.

    PubMed

    Lee, R F; Gonsoulin, F

    1979-01-01

    1. The predominant lipids of nerve cords, ganglion and brain from horseshoe crabs were cholesterol (11% of lipid) and phospholipid (81% of lipid). 2. Major phospholipids were phosphatidyl ethanolamine and phosphatidyl choline with lesser amounts of phosphatidyl serine and phosphatidyl inositol and sphingomyelin. 3. The phospholipid fraction was characterized by a high content of plasmalogen, i.e. alk-1-enyl acyl phosphatides, so that 42% of the ethanolamine phosphatides were the plasmalogen, phosphatidal ethanolamine. 4. Phosphatidyl choline and phosphatidyl ethanolamine were high in polyunsaturation with 20:4 and 20:5 major fatty acids. Sphingomyelin had predominantly long chain saturated fatty acids. 5. Cerebrosides and gangliosides, which are associated with vertebrate nerve tissues, were absent from nerves of horseshoe crabs.

  9. Zoothamnium duplicatum infestation of cultured horseshoe crabs (Limulus polyphemus).

    PubMed

    Shinn, Andrew P; Mühlhölzl, Alexander P; Coates, Christopher J; Metochis, Christoforos; Freeman, Mark A

    2015-02-01

    An outbreak of the sessile peritrich Zoothamnium duplicatum in a pilot, commercial-scale Limulus polyphemus hatchery resulted in the loss of ∼96% (40,000) second/third instar larvae over a 61day period. peritrich growth was heavy, leading to mechanical obstruction of the gills and physical damage. The peritrichs were controlled without resultant loss of juvenile crabs by administering 10ppm chlorine in freshwater for 1h and the addition of aquarium grade sand; a medium into which the crabs could burrow and facilitate cleaning of the carapace. Peritrich identity was confirmed from a partial SSU rDNA contiguous sequence of 1343bp (99.7% similarity to Z. duplicatum).

  10. A New Color Image of the Crab Nebula

    NASA Astrophysics Data System (ADS)

    Wainscoat, R. J.; Kormendy, K.

    1997-03-01

    A new color image of the Crab Nebula is presented. This is a $2782 \\times 1904$ pixel mosaic of CCD frames taken through \\B\\ (blue), \\V\\ (green), and \\R\\ (red) filters; it was carefully color balanced so that the Sun would appear white. The resolution of the final image is approximately 0\\farcs8 FWHM. The technique by which this image was constructed is described, and some aspects of the structure of the Crab Nebula revealed by the image are discussed. We also discuss the weaknesses of this technique for producing ``true-color'' images, and describe how our image would differ from what the human eye might see in a very large wide-field telescope. The structure of the inner part of the synchrotron nebula is compared with recent high-resolution images from the {\\it Hubble Space Telescope\\/} and from the Canada-France-Hawaii Telescope. (SECTION: Interstellar Medium and Nebulae)

  11. Eavesdropping in crabs: an agency for lady detection

    PubMed Central

    Milner, Richard N. C.; Jennions, Michael D.; Backwell, Patricia R. Y.

    2010-01-01

    Although conspicuous courtship displays are an effective way of attracting the attention of receptive females, they could provide valuable information to rival males on the location of these females. In fiddler crabs, males that see a receptive female wave their single, greatly enlarged claw in a highly conspicuous courtship display. We test whether other males use this courtship display to alert them to the presence of receptive females that they cannot directly see. We show that male fiddler crabs (Uca mjoebergi) eavesdrop on the courtship displays of nearby males to detect mate-searching females. This allows males to begin waving before a female becomes visible. Furthermore, males appear to adjust their waving according to the information available: eavesdropping males wave 12 times faster than non-courting males but only 1.7 times slower than males in full visual contact with the female. PMID:20519196

  12. Feeding Behavior of a Crab According to Cheliped Number

    PubMed Central

    de Oliveira, Diogo Nunes; Christofoletti, Ronaldo Adriano; Barreto, Rodrigo Egydio

    2015-01-01

    Cheliped loss through autotomy is a common reflexive response in decapod crustaceans. Cheliped loss has direct and indirect effects on feeding behavior which can affect population dynamics and the role of species in the community. In this study, we assessed the impact of autotomy (0, 1, or 2 cheliped loss) on feeding behavior in the crab Pachygrapsus transversus, an omnivorous and abundant species that inhabits subtropical intertidal rocky shores along the South Atlantic Ocean. Autotomy altered crab feeding patterns and foraging behavior; however, the time spent foraging on animal prey or algae was not affected. These results indicate a plasticity of feeding behavior in P. transversus, allowing them to maintain feeding when injured. PMID:26682546

  13. Cymonomid crabs of the MAINBAZA Expedition (Decapoda: Brachyura).

    PubMed

    Ahyong, Shane T

    2014-06-23

    Cymonomid crabs collected from the Mozambique Channel off Madagascar by the 2011 MAINBAZA Expedition are reported. Two species of Cymonomus A. Milne Edwards, 1880, are represented, of which one is new to science and the other, C. valdiviae Lankester, 1903, is rediscovered, being previously known only from the holotype. Three species of Cymonomidae are now known from the western Indian Ocean, including C. trifurcus Stebbing, 1920, from South Africa. 

  14. Silurian horseshoe crab illuminates the evolution of arthropod limbs.

    PubMed

    Briggs, Derek E G; Siveter, Derek J; Siveter, David J; Sutton, Mark D; Garwood, Russell J; Legg, David

    2012-09-25

    The basic arrangement of limbs in euarthropods consists of a uniramous head appendage followed by a series of biramous appendages. The body is divided into functional units or tagmata which are usually distinguished by further differentiation of the limbs. The living horseshoe crabs are remnants of a much larger diversity of aquatic chelicerates. The limbs of the anterior and posterior divisions of the body of living horseshoe crabs differ in the loss of the outer and inner ramus, respectively, of an ancestral biramous limb. Here we report a new fossil horseshoe crab from the mid-Silurian Lagerstätte in Herefordshire, United Kingdom (approximately 425 Myr B.P.), a site that has yielded a remarkably preserved assemblage of soft-bodied fossils. The limbs of the new form can be homologized with those of living Limulus, but retain an ancestral biramous morphology. Remarkably, however, the two limb branches originate separately, providing fossil evidence to suggest that repression or loss of gene expression might have given rise to the appendage morphology of Limulus. Both branches of the prosomal limbs of this new fossil are robust and segmented in contrast to their morphology in Cambrian arthropods, revealing that a true biramous limb was once present in chelicerates as well as in the mandibulates. PMID:22967511

  15. Cadmium inhibits the vitellogenesis of freshwater crab Sinopotamon henanense.

    PubMed

    Yang, Jian; Liu, Dongmei; Dahms, Hans-Uwe; Wang, Lan

    2015-07-01

    Cadmium (Cd) may pose risks to freshwater organisms, including crabs that live at the interface of sediments and water column all year round. One of the major changes that occur during oocyte maturation of crabs is the production of vitellin. In the present study, the authors investigated the effects of Cd on oocyte size, vitellin level, and vitellogenin (Vtg) messenger RNA (mRNA) expression in the ovary of the freshwater crab Sinopotamon henanense. The authors studied the impacts of Cd on carbohydrate as well as on the protein metabolism, metallothionein, glutathione (GSH) synthesis, energy-related parameters, and mRNA expression of genes involved in energy metabolism. After Cd treatment, vitellin concentration, Vtg mRNA expression, and oocyte diameter decreased. Less carbohydrate and enhanced protein catabolism were found in the ovary. Adenosine triphosphate to adenosine diphosphate (ATP:ADP) ratios, reduced nicotinamide adenine dinucleotide (NADH) to oxidized nicotinamide adenine dinucleotide (NAD(+) ) ratios, mitochondrial membrane potential, and energy production-related mRNA expressions increased in the ovary after 10 d Cd treatment and decreased after 20 d. Metallothionein and GSH synthesis were up-regulated after 10 d on Cd exposure. Moreover, Cd caused a time-dependent up-regulation of malondialdehyde. The authors' findings show significant effects of Cd on vitellogenesis, which suggests that Cd slows down vitellogenesis in S. henanense because of excessive energy consumption and an activated defense system.

  16. a Surprise from the Pulsar in the Crab Nebula

    NASA Astrophysics Data System (ADS)

    1995-11-01

    New observations of the spectrum of the rapidly spinning neutron star (the `pulsar') in the Crab Nebula have been carried out with the ESO 3.5-metre New Technology Telescope (NTT) by a group of Italian astronomers [1]. Because of greatly improved spectral resolution which allows to register even very fine details in the pulsar's spectrum, they are able to determine for the first time with high accuracy the overall dependance of the emission on wavelength, i.e. the `shape' of the spectrum. Quite unexpectedly, they also detect a hitherto unknown 100 A (10 nm) broad `absorption dip', which can be securely attributed to the pulsar. These results open an exciting new window for the study of the extreme physical processes close to a pulsar. The Nature of Pulsars It is estimated that there may be as many as 100 million neutron stars in our Galaxy. A neutron star is the superdense remnant of the extremely violent supernova explosion that occurs at the end of the life of a comparatively massive star. In fact, all stars that are more than about 6 times heavier than the Sun are believed to end their lives as supernovae. During the explosion, the central core of the dying star collapses in a few milliseconds and the matter at the centre is compressed to a density comparable to that of an atomic nucleus. Due to the enormous inward pressure, the atomic particles are squeezed together into a kind of neutron jam. The outcome is the formation of a neutron star with a diameter of 10-15 kilometres, weighing as much as the Sun. In accordance with the physical law that implies that the rotation momentum of the exploding star must be conserved, newborn neutron stars will rotate very rapidly around their axis, in some cases as fast as 100 times per second. In the same way, the new neutron star is expected to possess a strong magnetic field. Of these myriads of neutron stars, about 700 have been observed to emit radio pulses (hence the name `pulsar'). A few of these can also be detected

  17. Protistan parasites as mortality drivers in cold water crab fisheries.

    PubMed

    Frank Morado, J; Siddeek, M S M; Mullowney, Darrell R; Dawe, Earl G

    2012-06-01

    From a historical perspective, several protistan taxa, including the recently re-aligned Microsporidia, have been associated with or identified as causes of mortalities in crustacean populations. Depending upon the host species, associated protistan prevalences could be as low as 5% or approach 100%. It has generally been assumed that reported prevalences translated directly into significant mortalities that could impact the distribution and abundance of affected populations. However, this assumption may be incorrect especially when the dynamics of host-pathogen-environment interactions are not entirely understood. We will discuss the presumed impact of several protistan pathogens on temperate and cold water commercial crab species. By using selected examples such as a ciliate in the Dungeness crab (Cancer magister) and Hematodinium sp. infections in North Pacific crabs, we will attempt to contrast differences between prevalence and mortality, acute and chronic infections/mortalities, age or size selectivity of affected population, and geographically restricted and widespread epizootics. We will also briefly discuss the potential impact of environmental changes such as climate change and ocean acidification on both host and protistan pathogen.

  18. Differential escape from parasites by two competing introduced crabs

    USGS Publications Warehouse

    Blakeslee, April M.; Keogh, Carolyn L.; Byers, James E.; Kuris, Armand M.; Lafferty, Kevin D.; Torchin, Mark E.

    2009-01-01

    Although introduced species often interact with one another in their novel communities, the role of parasites in these interactions remains less clear. We examined parasite richness and prevalence in 2 shorecrab species with different invasion histories and residency times in an introduced region where their distributions overlap broadly. On the northeastern coast of the USA, the Asian shorecrab Hemigrapsus sanguineus was discovered 20 yr ago, while the European green crab Carcinus maenas has been established for over 200 yr. We used literature and field surveys to evaluate parasitism in both crabs in their native and introduced ranges. We found only 1 parasite species infecting H. sanguineus on the US East Coast compared to 6 species in its native range, while C. maenas was host to 3 parasite species on the East Coast compared to 10 in its native range. The prevalence of parasite infection was also lower for both crabs in the introduced range compared to their native ranges; however, the difference was almost twice as much for H. sanguineus as for C. maenas. There are several explanations that could contribute to C. maenas' greater parasite diversity than that of H. sanguineus on the US East Coast, including differences in susceptibility, time since introduction, manner of introduction (vector), distance from native range, taxonomic isolation, and the potential for parasite identification bias. Our study underscores not just that non-native species lose parasites upon introduction, but that they may do so differentially, with ramifications for their direct interactions and with potential community-level influences.

  19. Observation and Spectral Measurements of the Crab Nebula with Milagro

    NASA Technical Reports Server (NTRS)

    Abdo, A. A.; Allen, B. T.; Aune, T.; Benbow, W.; Berley, D.; Chen, C.; Christopher, G. E.; DeYoung, T.; Dingus, B. L.; Falcone, A.; Fleysher, L.; Fleysher, R.; Gonzalez, M. M.; Goodman, J. A.; Gordo, J. B.; Hays, E.; Hoffman, C. M.; Huntemeyer, P. H.; Kolterman, B. E.; Linnemann, J. T.; McEnery, J. E.; Morgan, T.; Mincer, A. I.; Nemethy, P.

    2011-01-01

    The Crab Nebula was detected with the Milagro experiment at a statistical significance of 17 standard deviations over the lifetime of the experiment. The experiment was sensitive to approximately 100 GeV - 100 TeV gamma ray air showers by observing the particle footprint reaching the ground. The fraction of detectors recording signals from photons at the ground is a suitable proxy for the energy of the primary particle and has been used to measure the photon energy spectrum of the Crab Nebula between 1 and 100 TeV. The TeV emission is believed to be caused by inverse-Compton up-scattering scattering of ambient photons by an energetic electron population. The location of a Te V steepening or cutoff in the energy spectrum reveals important details about the underlying electron population. We describe the experiment and the technique for distinguishing gamma-ray events from the much more-abundant hadronic events. We describe the calculation of the significance of the excess from the Crab and how the energy spectrum is fit.

  20. Silurian horseshoe crab illuminates the evolution of arthropod limbs

    NASA Astrophysics Data System (ADS)

    Briggs, Derek E. G.; Siveter, Derek J.; Siveter, David J.; Sutton, Mark D.; Garwood, Russell J.; Legg, David

    2012-09-01

    The basic arrangement of limbs in euarthropods consists of a uniramous head appendage followed by a series of biramous appendages. The body is divided into functional units or tagmata which are usually distinguished by further differentiation of the limbs. The living horseshoe crabs are remnants of a much larger diversity of aquatic chelicerates. The limbs of the anterior and posterior divisions of the body of living horseshoe crabs differ in the loss of the outer and inner ramus, respectively, of an ancestral biramous limb. Here we report a new fossil horseshoe crab from the mid-Silurian Lagerstätte in Herefordshire, United Kingdom (approximately 425 Myr B.P.), a site that has yielded a remarkably preserved assemblage of soft-bodied fossils. The limbs of the new form can be homologized with those of living Limulus, but retain an ancestral biramous morphology. Remarkably, however, the two limb branches originate separately, providing fossil evidence to suggest that repression or loss of gene expression might have given rise to the appendage morphology of Limulus. Both branches of the prosomal limbs of this new fossil are robust and segmented in contrast to their morphology in Cambrian arthropods, revealing that a true biramous limb was once present in chelicerates as well as in the mandibulates.

  1. Silurian horseshoe crab illuminates the evolution of arthropod limbs.

    PubMed

    Briggs, Derek E G; Siveter, Derek J; Siveter, David J; Sutton, Mark D; Garwood, Russell J; Legg, David

    2012-09-25

    The basic arrangement of limbs in euarthropods consists of a uniramous head appendage followed by a series of biramous appendages. The body is divided into functional units or tagmata which are usually distinguished by further differentiation of the limbs. The living horseshoe crabs are remnants of a much larger diversity of aquatic chelicerates. The limbs of the anterior and posterior divisions of the body of living horseshoe crabs differ in the loss of the outer and inner ramus, respectively, of an ancestral biramous limb. Here we report a new fossil horseshoe crab from the mid-Silurian Lagerstätte in Herefordshire, United Kingdom (approximately 425 Myr B.P.), a site that has yielded a remarkably preserved assemblage of soft-bodied fossils. The limbs of the new form can be homologized with those of living Limulus, but retain an ancestral biramous morphology. Remarkably, however, the two limb branches originate separately, providing fossil evidence to suggest that repression or loss of gene expression might have given rise to the appendage morphology of Limulus. Both branches of the prosomal limbs of this new fossil are robust and segmented in contrast to their morphology in Cambrian arthropods, revealing that a true biramous limb was once present in chelicerates as well as in the mandibulates.

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

    PubMed

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

    2014-01-01

    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 μg/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 μg/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

  3. Use of blue crab (Callinectes sapidus) embryos for toxicity testing

    SciTech Connect

    Lee, R.; O`Malley, K.

    1995-12-31

    After fertilization, blue crab embryos develop in egg sacs attached to the female pleopods, often referred to as the sponge. Lipovitellin and lipid droplets in the egg sacs provide energy and nutrition for the developing embryos. Embryos were removed from the sponge and transferred to 24 well culture plates containing sea water with or without toxicants, Each well contained 10 embryos. After 7 to 10 days, embryos hatched to swimming zoea. The effects of toxicants at various concentrations on hatching were determined and the EC{sub 50} calculated. For example, the EC{sub 50} for tributyltin, fenvalerate and mercuric chloride were 50, 30 and 90 ng/liter, respectively. The hatching success of control embryos ranged from 95 to 98%. Formation of the heart, eyespot formation, appendage formation and utilization rate of lipovitellin were also effected by exposure to toxicants. At a low concentration of mercuric ion (30ng/liter) the heart formed, but there was no heart beat. Eyespot formation was abnormal in the presence of high concentrations of cadmium (2 {micro}g/liter) and zinc (5 {micro}g/liter), Crab embryos offer many advantages for toxicity testing of pure compounds or mixtures in water, including toxicity testing of sediment pore water. The crab embryos may also serve as models to understand the effect of specific toxicants on the heart and eye spots of crustaceans.

  4. ACT Test

    MedlinePlus

    ... this page helpful? Also known as: ACT; Activated Coagulation Time Formal name: Activated Clotting Time Related tests: ... in the blood called platelets and proteins called coagulation factors are activated in a sequence of steps ...

  5. Acting Atoms.

    ERIC Educational Resources Information Center

    Farin, Susan Archie

    1997-01-01

    Describes a fun game in which students act as electrons, protons, and neutrons. This activity is designed to help students develop a concrete understanding of the abstract concept of atomic structure. (DKM)

  6. 77 FR 58624 - Progressive Rail Incorporated-Acquisition and Operation Exemption-Rail Lines of Crab Orchard...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... Lines of Crab Orchard & Egyptian Railroad Company Progressive Rail Incorporated (PGR), a Class III rail carrier, has filed a verified notice of exemption under 49 CFR 1150.41 to acquire from Crab...

  7. a Surprise from the Pulsar in the Crab Nebula

    NASA Astrophysics Data System (ADS)

    1995-11-01

    New observations of the spectrum of the rapidly spinning neutron star (the `pulsar') in the Crab Nebula have been carried out with the ESO 3.5-metre New Technology Telescope (NTT) by a group of Italian astronomers [1]. Because of greatly improved spectral resolution which allows to register even very fine details in the pulsar's spectrum, they are able to determine for the first time with high accuracy the overall dependance of the emission on wavelength, i.e. the `shape' of the spectrum. Quite unexpectedly, they also detect a hitherto unknown 100 A (10 nm) broad `absorption dip', which can be securely attributed to the pulsar. These results open an exciting new window for the study of the extreme physical processes close to a pulsar. The Nature of Pulsars It is estimated that there may be as many as 100 million neutron stars in our Galaxy. A neutron star is the superdense remnant of the extremely violent supernova explosion that occurs at the end of the life of a comparatively massive star. In fact, all stars that are more than about 6 times heavier than the Sun are believed to end their lives as supernovae. During the explosion, the central core of the dying star collapses in a few milliseconds and the matter at the centre is compressed to a density comparable to that of an atomic nucleus. Due to the enormous inward pressure, the atomic particles are squeezed together into a kind of neutron jam. The outcome is the formation of a neutron star with a diameter of 10-15 kilometres, weighing as much as the Sun. In accordance with the physical law that implies that the rotation momentum of the exploding star must be conserved, newborn neutron stars will rotate very rapidly around their axis, in some cases as fast as 100 times per second. In the same way, the new neutron star is expected to possess a strong magnetic field. Of these myriads of neutron stars, about 700 have been observed to emit radio pulses (hence the name `pulsar'). A few of these can also be detected

  8. 25 CFR 1000.401 - Can a Tribe/Consortium carry over funds not spent during the term of the AFA?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false Can a Tribe/Consortium carry over funds not spent during... AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT Miscellaneous Provisions § 1000.401 Can a...

  9. 25 CFR 1000.401 - Can a Tribe/Consortium carry over funds not spent during the term of the AFA?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Can a Tribe/Consortium carry over funds not spent during... AFFAIRS, DEPARTMENT OF THE INTERIOR ANNUAL FUNDING AGREEMENTS UNDER THE TRIBAL SELF-GOVERNMENT ACT AMENDMENTS TO THE INDIAN SELF-DETERMINATION AND EDUCATION ACT Miscellaneous Provisions § 1000.401 Can a...

  10. Acanthocephala Parasite (Profilicollis spp.) Loads in Correlation to Pacific Mole Crab (Emerita analoga) Size

    NASA Astrophysics Data System (ADS)

    Cheng, T.; Huang, S.; Galathe, M.; Jenkins, M.; Ramirez, A.; Crosby, L.; Barrera, J.; FitzHoward, S.

    2013-12-01

    Since 2002, San Francisco Bay students have been conducting marine ecosystem monitoring through a joint project with the Long-term Monitoring Program and Experiential Training for Students (LiMPETS), in conjunction with the Gulf of Farallones National Marine Sanctuary. Each year students collect population and demographic data on Pacific mole crabs (Emerita analoga), an indicator species that lives in the sandy beach habitat in temperate regions along the Pacific Ocean. Pacific mole crabs are filter feeding crustaceans that inhabit the intertidal swash zone and are known to be an intermediate host for parasitic ';spiny-headed' worms in the phylum Acanthocephala (Profilicollis spp.). Sampling takes place during their reproductive period, which occurs from spring to fall, and includes measuring total body length of the Pacific mole crabs and dissecting them to determine presence of Acanthocephalan parasites. We hypothesize that due to larger body mass, larger Pacific mole crabs will have a greater number of Acanthocephala parasites.We conducted several analyses using the LiMPETS long-term data. Specifically, we compared body length, crab gender, and parasite abundance from Pacific mole crabs sampled from four beaches located in the county and city of San Francisco. Our results indicated that larger Pacific mole crabs do not necessarily have more parasites, but are more likely to have at least one parasite, while female Pacific mole crabs carrying eggs, have more parasites than males or females without eggs. We also found that parasite loads per mole crab was highest in the spring. Further analysis will be conducted to determine factors affecting Pacific mole crab parasite loads. Studying Pacific mole crabs help evaluate the health of California's intertidal systems and how human activities, geologic changes, and climate changes all make huge impacts to the intertidal ecosystems.

  11. Effects of coral bleaching on the obligate coral-dwelling crab Trapezia cymodoce

    NASA Astrophysics Data System (ADS)

    Stella, J. S.; Munday, P. L.; Jones, G. P.

    2011-09-01

    Corals are an essential and threatened habitat for a diverse range of reef-associated animals. Episodes of coral bleaching are predicted to increase in frequency and intensity over coming decades, yet the effects of coral-host bleaching on the associated animal communities remain poorly understood. The present study investigated the effects of host-colony bleaching on the obligate coral-dwelling crab, Trapezia cymodoce, during a natural bleaching event in the lagoon of Lizard Island, Australia. Branching corals, which harbour the highest diversity of coral associates, comprised 13% of live coral cover at the study site, with 83% affected by bleaching. Crabs on healthy and bleached colonies of Pocillopora damicornis were monitored over a 5-week period to determine whether coral bleaching affected crab density and movement patterns. All coral colonies initially contained one breeding pair of crabs. There was a significant decline in crab density on bleached corals after 5 weeks, with many corals losing one or both crabs, yet all healthy colonies retained a mating pair. Fecundity of crabs collected from bleached and healthy colonies of P. damicornis was also compared. The size of egg clutches of crabs collected from bleached hosts was 40% smaller than those from healthy hosts, indicating a significant reduction in fecundity. A laboratory experiment on movement patterns found that host-colony bleaching also prompted crabs to emigrate in search of more suitable colonies. Emigrant crabs engaged in aggressive interactions with occupants of healthy hosts, with larger crabs always usurping occupants of a smaller size. Decreased densities and clutch sizes, along with increased competitive interactions, could potentially result in a population decline of these important coral associates with cascading effects on coral health.

  12. Effect of food availability on the growth and thermal physiology of juvenile Dungeness crabs (Metacarcinus magister)

    PubMed Central

    McLean, Katherine M.; Todgham, Anne E.

    2015-01-01

    Juvenile Dungeness crabs spend ~1 year in the San Francisco Estuary, where they undergo considerable growth before returning to the coastal ocean. Previous studies suggest that competition, food scarcity and avoidance of conspecifics may cause some juvenile Dungeness crabs in the San Francisco Estuary to become food limited. Food limitation may force these crabs to forage in higher temperature intertidal environments in the estuary, exposing them to stressful conditions in order to sustain growth and, potentially, necessitating physiological trade-offs in energy allocation between growth and stress tolerance. To investigate the effects of food limitation on aerobic metabolism and physiological performance of crabs, we assessed growth, moulting frequency, metabolic rate, citrate synthase and malate dehydrogenase enzyme activity and cardiac performance, as an index of temperature sensitivity and upper temperature tolerance. Summer- and winter-caught crabs were acclimated to either a high- or a low-food ration for 5 weeks. Overall, our results demonstrated that while food limitation had a negative effect on growth of juvenile Dungeness crabs in both the summer and the winter feeding trials, crabs in the low-food group maintained both metabolic rate at ambient San Francisco Estuary temperatures (15°C; summer trial only) and upper temperature tolerance as determined by failure of cardiac function when compared with crabs in the high-food group (summer and winter trials). Therefore, the ability to maintain stress tolerance when food is limited appears to come as a physiological trade-off to growth. Food-limited crabs were unable to increase their metabolic rate to the same level as that achieved by well-fed crabs; therefore, if exposure to elevated temperatures persists and requires more energy than can be met by crabs in their food-limited state, physiological performance may be compromised. PMID:27293698

  13. Identification of tropomyosin and arginine kinase as major allergens of Portunus pelagicus (blue swimming crab).

    PubMed

    Rosmilah, M; Shahnaz, M; Zailatul, H M Y; Noormalin, A; Normilah, I

    2012-09-01

    Crab is an important source of food allergen. Tropomyosin represents the main crab allergen and is responsible for IgE cross-reactivity between various species of crustaceans. Recently, other new crab allergens including arginine kinase have been identified. However, information on allergens of the local Portunidcrab is not available. Thus, the aim of this study was to identify the major allergens of Portunus pelagicus (blue swimming crab) using the allergenomics approach. Raw and cooked extracts of the crab were prepared from the crab meat. Protein profile and IgE binding pattern were demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from 30 patients with crab allergy. The major allergens of the crab were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry analysis of the peptide digests. The SDS-PAGE of raw extract revealed approximately 20 protein fractions over a wide molecular weight range, while cooked extract demonstrated fewer protein bands. The raw extract also demonstrated a higher number of IgE reactive bands than the cooked extract. A heat-resistant protein of 36 kDa has been identified as the major allergen in both raw and cooked extracts. In addition, a heat-sensitive protein of 41 kDa was also recognized as a major allergen in raw crab. The 2-DE gel profile of the raw extract demonstrated about >100 distinct proteins spots and immunoblotting of the 2-DE profile demonstrated at least 12 different major IgE reactive spots with molecular masses between 13 to 250 kDa and isoelectric point (pI) values ranging from 4.0 to 7.0. The 36 and 41 kDa proteins were identified as the crab tropomyosin and arginine kinase, respectively by mass spectrometry. Therefore, this study confirmed that tropomyosin and arginine kinase are the major allergens of the local Portunid crab, P. pelagicus.

  14. (1)H NMR metabolomic profiling of the blue crab (Callinectes sapidus) from the Adriatic Sea (SE Italy): A comparison with warty crab (Eriphia verrucosa), and edible crab (Cancer pagurus).

    PubMed

    Zotti, Maurizio; De Pascali, Sandra Angelica; Del Coco, Laura; Migoni, Danilo; Carrozzo, Leonardo; Mancinelli, Giorgio; Fanizzi, Francesco Paolo

    2016-04-01

    The metabolomic profile of blue crab (Callinectes sapidus) captured in the Acquatina lagoon (SE Italy) was compared to an autochthonous (Eriphia verrucosa) and to a commercial crab species (Cancer pagurus). Both lipid and aqueous extracts of raw claw muscle were analyzed by (1)H NMR spectroscopy and MVA (multivariate data analysis). Aqueous extracts were characterized by a higher inter-specific discriminating power compared to lipid fractions. Specifically, higher levels of glutamate, alanine and glycine characterized the aqueous extract of C. sapidus, while homarine, lactate, betaine and taurine characterized E. verrucosa and C. pagurus. On the other hand, only the signals of monounsaturated fatty acids distinguished the lipid profiles of the three crab species. These results support the commercial exploitation and the integration of the blue crab in human diet of European countries as an healthy and valuable seafood.

  15. (1)H NMR metabolomic profiling of the blue crab (Callinectes sapidus) from the Adriatic Sea (SE Italy): A comparison with warty crab (Eriphia verrucosa), and edible crab (Cancer pagurus).

    PubMed

    Zotti, Maurizio; De Pascali, Sandra Angelica; Del Coco, Laura; Migoni, Danilo; Carrozzo, Leonardo; Mancinelli, Giorgio; Fanizzi, Francesco Paolo

    2016-04-01

    The metabolomic profile of blue crab (Callinectes sapidus) captured in the Acquatina lagoon (SE Italy) was compared to an autochthonous (Eriphia verrucosa) and to a commercial crab species (Cancer pagurus). Both lipid and aqueous extracts of raw claw muscle were analyzed by (1)H NMR spectroscopy and MVA (multivariate data analysis). Aqueous extracts were characterized by a higher inter-specific discriminating power compared to lipid fractions. Specifically, higher levels of glutamate, alanine and glycine characterized the aqueous extract of C. sapidus, while homarine, lactate, betaine and taurine characterized E. verrucosa and C. pagurus. On the other hand, only the signals of monounsaturated fatty acids distinguished the lipid profiles of the three crab species. These results support the commercial exploitation and the integration of the blue crab in human diet of European countries as an healthy and valuable seafood. PMID:26593533

  16. 50 CFR Table 36 to Part 679 - Percentage of Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Percentage of Crab and Halibut PSC Limit... Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species For the following PSCspecies . . . The....47 24.19 31.72 Zone 1 Red king crab 0.14% 0.56% 6.88% 0.48% 61.79% 30.16% C. opilio crab (COBLZ) 0%...

  17. 50 CFR Table 36 to Part 679 - Percentage of Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Percentage of Crab and Halibut PSC Limit... Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species For the following PSCspecies . . . The....47 24.19 31.72 Zone 1 Red king crab 0.14% 0.56% 6.88% 0.48% 61.79% 30.16% C. opilio crab (COBLZ) 0%...

  18. 50 CFR Table 36 to Part 679 - Percentage of Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Percentage of Crab and Halibut PSC Limit... Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species For the following PSCspecies . . . The....47 24.19 31.72 Zone 1 Red king crab 0.14% 0.56% 6.88% 0.48% 61.79% 30.16% C. opilio crab (COBLZ) 0%...

  19. 50 CFR Table 36 to Part 679 - Percentage of Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Percentage of Crab and Halibut PSC Limit... Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species For the following PSCspecies . . . The....47 24.19 31.72 Zone 1 Red king crab 0.14% 0.56% 6.88% 0.48% 61.79% 30.16% C. opilio crab (COBLZ) 0%...

  20. 50 CFR Table 36 to Part 679 - Percentage of Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Percentage of Crab and Halibut PSC Limit... Crab and Halibut PSC Limit Assigned to Each Amendment 80 Species For the following PSCspecies . . . The....47 24.19 31.72 Zone 1 Red king crab 0.14% 0.56% 6.88% 0.48% 61.79% 30.16% C. opilio crab (COBLZ) 0%...

  1. Locomotion, respiratory physiology, and energetics of amphibious and terrestrial crabs.

    PubMed

    Adamczewska, A M; Morris, S

    2000-01-01

    The transition from breathing air to breathing water requires physiological and morphological adaptations. The study of crustaceans in transitional habitats provides important information as to the nature of these adaptations. This article addresses the physiology of air breathing in amphibious and terrestrial crabs and their relative locomotor abilities. Potamonautes warreni is an apparently amphibious freshwater crab from southern Africa, Cardisoma hirtipes is an air-breathing gecarcinid crab with some dependency on freshwater, and Gecarcoidea natalis is an obligate air-breathing gecarcinid endemic to Christmas Island in the Indian Ocean. All three species have well-developed lungs but retain gills and show seasonally different activity patterns that, in the gercarcinids, especially G. natalis, include long-distance breeding migrations. The three species were better at breathing air than water, but P. warreni was the best at breathing water. Cardisoma hirtipes is essentially an obligate air breather and appears to experience facultative hypometabolism during immersion. Cardisoma hirtipes has a haemocyanin with a high affinity for O(2) that facilitates loading from air but makes 30% of the Hc bound O(2) inaccessible. The gecarcinids but not P. warreni show increased diffusion limitation for O(2) over the lung during exercise. Gecarcoidea natalis outperforms C. hirtipes by virtue of a unique haemolymph shunt from the lung into the gills. Paradoxically, it is modifications of the gills for aerial O(2) uptake in G. natalis that allow for relatively greater haemolymph oxygenation. Despite showing decreased arterial-venous DeltaPo(2), P. warreni increased the arterial-venous Delta[O(2)] with no recourse to anaerobiosis during 5 min exercise. In the short term, P. warreni is more adept at walking than C. hirtipes. The breeding migrations of C. hirtipes and G. natalis were completely aerobic, but G. natalis walk farther and probably faster. Seasonal changes in underlying

  2. Contextual Cross-Referencing of Species Names for Fiddler Crabs (Genus Uca): An Experiment in Cyber-Taxonomy

    PubMed Central

    Rosenberg, Michael S.

    2014-01-01

    Cyber-taxonomy of name usage has focused primarily on producing authoritative lists of names or cross-linking names and data across disparate databases. A feature missing from much of this work is the recording and analysis of the context in which a name was used—context which can be critical for understanding not only what name an author used, but to which currently recognized species they actually refer. An experiment on recording contextual information associated with name usage was conducted for the fiddler crabs (genus Uca). Data from approximately one quarter of all publications that mention fiddler crabs, including 95% of those published prior to 1924 and 67% of those published prior to 1976, have currently been recorded in a database. Approaches and difficulties in recording and analyzing the context of name use are discussed. These results are not meant to be a full solution, rather to highlight problems which have not been previously investigated and may act as a springboard for broader approaches and discussion. Some data on the accessibility of the literature, including in particular electronic forms of publication, are also presented. The resulting data has been integrated for general browsing into the website http://www.fiddlercrab.info; the raw data and code used to construct the website is available at https://github.com/msrosenberg/fiddlercrab.info. PMID:25004097

  3. 40 CFR 408.80 - Applicability; description of the dungeness and tanner crab processing in the contiguous States...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... dungeness and tanner crab processing in the contiguous States subcategory. 408.80 Section 408.80 Protection... AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Dungeness and Tanner Crab Processing in the Contiguous States Subcategory § 408.80 Applicability; description of the dungeness and tanner crab...

  4. 40 CFR 408.80 - Applicability; description of the dungeness and tanner crab processing in the contiguous States...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dungeness and tanner crab processing in the contiguous States subcategory. 408.80 Section 408.80 Protection... AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Dungeness and Tanner Crab Processing in the Contiguous States Subcategory § 408.80 Applicability; description of the dungeness and tanner crab...

  5. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  6. 40 CFR 408.80 - Applicability; description of the dungeness and tanner crab processing in the contiguous States...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... dungeness and tanner crab processing in the contiguous States subcategory. 408.80 Section 408.80 Protection... AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Dungeness and Tanner Crab Processing in the Contiguous States Subcategory § 408.80 Applicability; description of the dungeness and tanner crab...

  7. 76 FR 15275 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Golden Crab Fishery Off the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

    ..., Gulf of Mexico, and South Atlantic; Golden Crab Fishery Off the Southern Atlantic States; Control Date... crab fishery operating in the exclusive economic zone (EEZ) of the South Atlantic. If changes to the... Fishery Management Council (Council) and NMFS consider whether and how access to the golden crab...

  8. 76 FR 43250 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Stone Crab Fishery of the Gulf of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ..., Gulf of Mexico, and South Atlantic; Stone Crab Fishery of the Gulf of Mexico; Removal of Regulations... Management Plan for the Stone Crab Fishery of the Gulf of Mexico (FMP) and remove its implementing regulations, as requested by the Gulf of Mexico Fishery Management Council (Council). The stone crab...

  9. 76 FR 36511 - Fisheries of the Northeastern United States; Atlantic Deep-Sea Red Crab; Amendment 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... United States; Atlantic Deep-Sea Red Crab; Amendment 3 AGENCY: National Marine Fisheries Service (NMFS... Fishery Management Council (Council) has submitted Amendment 3 to the Atlantic Deep-Sea Red Crab Fishery... envelope, ``Comments on Red Crab Amendment 3.'' Instructions: All comments received are part of the...

  10. 76 FR 98 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Amendment 5 to the Golden Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-03

    ..., and South Atlantic; Amendment 5 to the Golden Crab Fishery Management Plan of the South Atlantic... management actions to be included in Amendment 5 to the Golden Crab Fishery Management Plan of the South... for the golden crab fishery. The purpose of this NOI is to solicit public comments on the scope...

  11. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  12. 40 CFR 408.80 - Applicability; description of the dungeness and tanner crab processing in the contiguous States...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... dungeness and tanner crab processing in the contiguous States subcategory. 408.80 Section 408.80 Protection... AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Dungeness and Tanner Crab Processing in the Contiguous States Subcategory § 408.80 Applicability; description of the dungeness and tanner crab...

  13. 40 CFR 408.80 - Applicability; description of the dungeness and tanner crab processing in the contiguous States...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... dungeness and tanner crab processing in the contiguous States subcategory. 408.80 Section 408.80 Protection... AND PRESERVED SEAFOOD PROCESSING POINT SOURCE CATEGORY Dungeness and Tanner Crab Processing in the Contiguous States Subcategory § 408.80 Applicability; description of the dungeness and tanner crab...

  14. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  15. 75 FR 48298 - Groundfish Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea/Aleutian Islands Crab...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-10

    ... Exclusive Economic Zone Off Alaska; Bering Sea/Aleutian Islands Crab Rationalization Program; Recordkeeping... removes the Crab Rationalization Program requirements for catcher/processors to weigh all offloaded crab... INFORMATION CONTACT: Patsy A. Bearden, 907-586-7228. SUPPLEMENTARY INFORMATION: NMFS manages the U.S....

  16. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  17. 40 CFR 408.40 - Applicability; description of the non-remote Alaskan crab meat processing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-remote Alaskan crab meat processing subcategory. 408.40 Section 408.40 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Non-Remote Alaskan Crab Meat Processing Subcategory § 408.40 Applicability; description of the non-remote Alaskan crab meat processing subcategory. The provisions of this subpart...

  18. 50 CFR 600.1104 - Bering Sea and Aleutian Islands (BSAI) crab species fee payment and collection system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... endorsement for Norton Sound red king. More specifically, the reduction endorsement fisheries, and the crab... endorsement fisheries, are: (1) Bristol Bay red king (the corresponding crab rationalization fishery is Bristol Bay red king crab), (2) Bering Sea and Aleutian Islands Area C. opilio and C. bairdi...

  19. 50 CFR 600.1104 - Bering Sea and Aleutian Islands (BSAI) crab species fee payment and collection system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... endorsement for Norton Sound red king. More specifically, the reduction endorsement fisheries, and the crab... endorsement fisheries, are: (1) Bristol Bay red king (the corresponding crab rationalization fishery is Bristol Bay red king crab), (2) Bering Sea and Aleutian Islands Area C. opilio and C. bairdi...

  20. 50 CFR 600.1104 - Bering Sea and Aleutian Islands (BSAI) crab species fee payment and collection system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... endorsement for Norton Sound red king. More specifically, the reduction endorsement fisheries, and the crab... endorsement fisheries, are: (1) Bristol Bay red king (the corresponding crab rationalization fishery is Bristol Bay red king crab), (2) Bering Sea and Aleutian Islands Area C. opilio and C. bairdi...

  1. 50 CFR 600.1104 - Bering Sea and Aleutian Islands (BSAI) crab species fee payment and collection system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... endorsement for Norton Sound red king. More specifically, the reduction endorsement fisheries, and the crab... endorsement fisheries, are: (1) Bristol Bay red king (the corresponding crab rationalization fishery is Bristol Bay red king crab), (2) Bering Sea and Aleutian Islands Area C. opilio and C. bairdi...

  2. 50 CFR 600.1104 - Bering Sea and Aleutian Islands (BSAI) crab species fee payment and collection system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... endorsement for Norton Sound red king. More specifically, the reduction endorsement fisheries, and the crab... endorsement fisheries, are: (1) Bristol Bay red king (the corresponding crab rationalization fishery is Bristol Bay red king crab), (2) Bering Sea and Aleutian Islands Area C. opilio and C. bairdi...

  3. 50 CFR 680.40 - Crab Quota Share (QS), Processor QS (PQS), Individual Fishing Quota (IFQ), and Individual...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... stationary floating crab processor. (3) PQS issued to Blue Dutch, LLC. (i) Pursuant to Public Law 109-241... crab QS fishery. (ii) PQS units issued to Blue Dutch, LLC, under paragraph (e)(3)(i) of this section... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Crab Quota Share (QS), Processor QS...

  4. 50 CFR 680.40 - Crab Quota Share (QS), Processor QS (PQS), Individual Fishing Quota (IFQ), and Individual...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... stationary floating crab processor. (3) PQS issued to Blue Dutch, LLC. (i) Pursuant to Public Law 109-241... crab QS fishery. (ii) PQS units issued to Blue Dutch, LLC, under paragraph (e)(3)(i) of this section... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Quota Share (QS), Processor QS...

  5. 50 CFR 680.40 - Crab Quota Share (QS), Processor QS (PQS), Individual Fishing Quota (IFQ), and Individual...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... stationary floating crab processor. (3) PQS issued to Blue Dutch, LLC. (i) Pursuant to Public Law 109-241... crab QS fishery. (ii) PQS units issued to Blue Dutch, LLC, under paragraph (e)(3)(i) of this section... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Crab Quota Share (QS), Processor QS...

  6. Mangrove crab ( Scylla serrata) populations may sometimes be best managed locally

    NASA Astrophysics Data System (ADS)

    Ewel, Katherine C.

    2008-02-01

    Mangrove crabs ( Scylla serrata) were trapped in summer and fall 2004 at four sites, each in a separate municipality on the Pacific island of Kosrae, Federated States of Micronesia. Carapace width (CW) of the 219 crabs averaged 15.1 ± 0.13 cm (SE), slightly larger than the mean size of 221 crabs trapped from the same sites 4 y earlier. Mean CW of the 56 crabs in the upper quartile was 17.5 ± 0.17 cm (SE). In the current study, both sizes of crabs as well as degree and direction of change in size from summer to winter varied among the municipalities. The average CW of crabs from one municipality was significantly larger than from any of the other municipalities. Average CW of crabs from another municipality decreased from summer to fall. These results suggest that although the island-wide crab population appears to be stable, some municipalities may wish to enact site-specific management policies to obtain a harvest regimen that will meet local needs.

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

    USGS Publications Warehouse

    Kuris, A.M.; Torchin, M.E.; Lafferty, K.D.

    2002-01-01

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

  8. Dungeness crab survey for the Southwest Ocean Disposal Site off Grays Harbor, Washington, June 1990

    SciTech Connect

    Higgins, B.J.; Pearson, W.H. )

    1991-09-01

    As part of the Grays Harbor Navigation Improvement Project, the Seattle District of the US Army Corps of Engineers has begun active use of the Southwest Ocean Disposal Site off Grays Harbor, Washington. This survey was to verify that the location of the area of high crab density observed during site selection surveys has not shifted into the Southeast Ocean Disposal Site. In June 1990, mean densities of juvenile Dungeness crab were 146 crab/ha within the disposal site and 609 crab/ha outside ad north of the disposal site. At nearshore locations outside the disposal site, juvenile crab density was 3275 crab/ha. Despite the low overall abundance, the spatial distribution of crab was such that the high crab densities in 1990 have remained outside the Southwest Ocean Disposal Site. The survey data have confirmed the appropriateness of the initial selection of the disposal site boundaries and indicated no need to move to the second monitoring tier. 8 refs., 9 figs., 2 tabs.

  9. Associations between dioxins/furans and dioxin-like PCBs in estuarine sediment and blue crab

    USGS Publications Warehouse

    Liebens, J.; Mohrherr, C.J.; Karouna-Renier, N. K.; Snyder, R.A.; Rao, K.R.

    2011-01-01

    The objective of the present study was to evaluate the relationships between the quantity, toxicity, and compositional profile of dioxin/furan compounds (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in estuarine sediment and in the blue crab (Callinectes sapidus). Sediment and blue crab samples were collected in three small urban estuaries that are in relatively close proximity to each other. Results show that differences between PCDD/F and DL-PCB mass concentrations and total toxic equivalents (TEQ) toxicity in sediments of the three estuaries are reflected in those of the blue crab. TEQs are higher in the hepatopancreas of the crabs than in the sediment, but the concentration factor is inversely proportional to the TEQ in the sediments. Congener profiles in the crabs are systematically different from those in the sediments, and the difference is more pronounced for PCDD/Fs than for DL-PCBs, possibly due to differences in metabolization rates. Compared with sediment profiles, more lesser-chlorinated PCDD/Fs that have higher TEFs accumulate in crab hepatopancreas. This selective bioaccumulation of PCDD/Fs results in a TEQ augmentation in crab hepatopancreas compared with sediments. The bioaccumulation in the blue crab is also selective for PCDD/Fs over DL-PCBs. ?? 2011 Springer Science+Business Media B.V.

  10. 50 CFR 654.24 - Shrimp/stone crab separation zones.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Shrimp/stone crab separation zones. 654... Measures § 654.24 Shrimp/stone crab separation zones. Five zones are established in the management area and Florida's waters off Citrus and Hernando Counties for the separation of shrimp trawling and stone...

  11. 50 CFR 654.24 - Shrimp/stone crab separation zones.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Shrimp/stone crab separation zones. 654.24... Measures § 654.24 Shrimp/stone crab separation zones. Five zones are established in the management area and Florida's waters off Citrus and Hernando Counties for the separation of shrimp trawling and stone...

  12. Growth, reproduction & population structure of the freshwater crab Sinopotamon yangtsekiense bott, 1967, from Zhejiang, China

    NASA Astrophysics Data System (ADS)

    Chen, Tao; Lai, Wei; Du, Nan-Shan

    1994-03-01

    Monthly investigations were mae on the population of Chinese freshwater crab, Sinopotamon yangtsekiense Bott, 1967 from April, 1984 to March, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs' major development occurred from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June October. Females bearing eggs were taken from June August, and crabs with young were found from July October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-born crabs become mature after 1 2 years. The sex ratio was approximately 1∶1 in the overall population. However, the larger crabs are predominantly male. The age distribution of S. yangtsekinese was estimated from size frequency histograms. There were more adult crabs (over 70%) from June to October and more immature crabs (over 50%) from November to May.

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

    EPA Science Inventory

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

  14. Giant robber crabs monitored from space: GPS-based telemetric studies on Christmas Island (Indian Ocean).

    PubMed

    Krieger, Jakob; Grandy, Ronald; Drew, Michelle M; Erland, Susanne; Stensmyr, Marcus C; Harzsch, Steffen; Hansson, Bill S

    2012-01-01

    We investigated the navigational capabilities of the world's largest land-living arthropod, the giant robber crab Birgus latro (Anomura, Coenobitidae); this crab reaches 4 kg in weight and can reach an age of up to 60 years. Populations are distributed over small Indo-Pacific islands of the tropics, including Christmas Island (Indian Ocean). Although this species has served as a crustacean model to explore anatomical, physiological, and ecological aspects of terrestrial adaptations, few behavioral analyses of it exist. We used a GPS-based telemetric system to analyze movements of freely roaming robber crabs, the first large-scale study of any arthropod using GPS technology to monitor behavior. Although female robber crabs are known to migrate to the coast for breeding, no such observations have been recorded for male animals. In total, we equipped 55 male robber crabs with GPS tags, successfully recording more than 1,500 crab days of activity, and followed some individual animals for as long as three months. Besides site fidelity with short-distance excursions, our data reveal long-distance movements (several kilometers) between the coast and the inland rainforest. These movements are likely related to mating, saltwater drinking and foraging. The tracking patterns indicate that crabs form route memories. Furthermore, translocation experiments show that robber crabs are capable of homing over large distances. We discuss if the search behavior induced in these experiments suggests path integration as another important navigation strategy. PMID:23166774

  15. 50 CFR Table 3b to Part 680 - Crab Disposition or Product Codes

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Crab Disposition or Product Codes 3b Table 3b to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ZONE OFF ALASKA Pt. 680, Table 3b Table 3b to Part 680—Crab Disposition or Product Codes...

  16. 50 CFR Figure 13 to Part 679 - BSAI C. Opilio Tanner Crab Bycatch Limitations Zone

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false BSAI C. Opilio Tanner Crab Bycatch Limitations Zone 13 Figure 13 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Fig. 13 Figure 13 to Part 679—BSAI C. Opilio Tanner Crab...

  17. 50 CFR Table 3b to Part 680 - Crab Disposition or Product Codes

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Crab Disposition or Product Codes 3b Table 3b to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ZONE OFF ALASKA Pt. 680, Table 3b Table 3b to Part 680—Crab Disposition or Product Codes...

  18. 50 CFR Figure 13 to Part 679 - BSAI C. Opilio Tanner Crab Bycatch Limitations Zone

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false BSAI C. Opilio Tanner Crab Bycatch Limitations Zone 13 Figure 13 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Fig. 13 Figure 13 to Part 679—BSAI C. Opilio Tanner Crab...

  19. 50 CFR Table 3b to Part 680 - Crab Disposition or Product Codes

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Crab Disposition or Product Codes 3b Table 3b to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ZONE OFF ALASKA Pt. 680, Table 3b Table 3b to Part 680—Crab Disposition or Product Codes...

  20. 50 CFR Figure 13 to Part 679 - BSAI C. Opilio Tanner Crab Bycatch Limitations Zone

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false BSAI C. Opilio Tanner Crab Bycatch Limitations Zone 13 Figure 13 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Fig. 13 Figure 13 to Part 679—BSAI C. Opilio Tanner Crab...

  1. 50 CFR Figure 13 to Part 679 - BSAI C. Opilio Tanner Crab Bycatch Limitations Zone

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false BSAI C. Opilio Tanner Crab Bycatch Limitations Zone 13 Figure 13 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Fig. 13 Figure 13 to Part 679—BSAI C. Opilio Tanner Crab...

  2. 50 CFR Figure 13 to Part 679 - BSAI C. Opilio Tanner Crab Bycatch Limitations Zone

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false BSAI C. Opilio Tanner Crab Bycatch Limitations Zone 13 Figure 13 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... ECONOMIC ZONE OFF ALASKA Pt. 679, Fig. 13 Figure 13 to Part 679—BSAI C. Opilio Tanner Crab...

  3. 50 CFR Table 3b to Part 680 - Crab Disposition or Product Codes

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Crab Disposition or Product Codes 3b Table 3b to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ZONE OFF ALASKA Pt. 680, Table 3b Table 3b to Part 680—Crab Disposition or Product Codes...

  4. 50 CFR Table 3b to Part 680 - Crab Disposition or Product Codes

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Crab Disposition or Product Codes 3b Table 3b to Part 680 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ZONE OFF ALASKA Pt. 680, Table 3b Table 3b to Part 680—Crab Disposition or Product Codes...

  5. Beam dynamics aspects of crab cavities in the CERN Large Hadron Collider

    SciTech Connect

    Sun, Y.; Calaga, R.; Assmann, R.; Barranco, J.; Tomas, R.; Weiler, T.; Zimmermann, F.; Morita, A.

    2009-10-14

    Modern colliders bring into collision a large number of bunches to achieve a high luminosity. The long-range beam-beam effects arising from parasitic encounters at such colliders are mitigated by introducing a crossing angle. Under these conditions, crab cavities (CC) can be used to restore effective head-on collisions and thereby to increase the geometric luminosity. Such crab cavities have been proposed for both linear and circular colliders. The crab cavities are rf cavities operated in a transverse dipole mode, which imparts on the beam particles a transverse kick that varies with the longitudinal position along the bunch. The use of crab cavities in the Large Hadron Collider (LHC) may not only raise the luminosity, but it could also complicate the beam dynamics, e.g., crab cavities might not only cancel synchrobetatron resonances excited by the crossing angle but they could also excite new ones, they could reduce the dynamic aperture for off-momentum particles, they could influence the aperture and orbit, also degrade the collimation cleaning efficiency, and so on. In this paper, we explore the principal feasibility of LHC crab cavities from a beam dynamics point of view. The implications of the crab cavities for the LHC optics, analytical and numerical luminosity studies, dynamic aperture, aperture and beta beating, emittance growth, beam-beam tune shift, long-range collisions, and synchrobetatron resonances, crab dispersion, and collimation efficiency will be discussed.

  6. 50 CFR 600.1103 - Bering Sea and Aleutian Islands (BSAI) Crab species program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Bering Sea and Aleutian Islands (BSAI... Aleutian Islands (BSAI) Crab species program. (a) Purpose. This section's purpose is to implement the... Fishery Management Plan for the Bering Sea/Aleutian Islands King and Tanner Crabs pursuant to § 679.2...

  7. 50 CFR 600.1103 - Bering Sea and Aleutian Islands (BSAI) Crab species program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Bering Sea and Aleutian Islands (BSAI... Aleutian Islands (BSAI) Crab species program. (a) Purpose. This section's purpose is to implement the... Fishery Management Plan for the Bering Sea/Aleutian Islands King and Tanner Crabs pursuant to § 679.2...

  8. Dioxins, PCBs and heavy metals in Chinese mitten crabs from Dutch rivers and lakes.

    PubMed

    Hoogenboom, Ron L A P; Kotterman, Michiel J J; Hoek-van Nieuwenhuizen, Marion; van der Lee, Martijn K; Mennes, Wim C; Jeurissen, Suzanne M F; van Leeuwen, Stefan P J

    2015-03-01

    Chinese mitten crab is an invasive species in many European rivers and lakes. Data from the UK indicated high levels of dioxins and PCBs, in particular in the brown meat in the body. This was confirmed by studies in the Netherlands, showing average levels of dioxins and PCBs in the meat in the body of 43 pg TEQ g(-1) ww in crabs caught in the large rivers. Levels in crab of lakes in the Northern part of the Netherlands were on average 3.7-fold lower. Consumption of crabs from polluted areas results in a relatively high dose of dioxins and dl-PCBs and could significantly increase the intake above the TWI. However, in general consumption of these crabs is low, even in the Asian sub-population in the Netherlands. Cadmium and lead levels were higher in crabs from contaminated areas, but for mercury and arsenic there was no clear difference. Consumption of crabs would not result in significant risks for cadmium and mercury. For lead the daily intake could be raised above the BMDL01 for neurodevelopmental toxicity, but this would only occur on a limited number of days. For arsenic the exposure would exceed the lower end of the BMDL01 values for certain cancers, but again, the infrequent consumption by most consumers reduces this risk. Furthermore, speciation showed that most arsenic in crabs was probably not a toxic inorganic form, but likely to be in an organic form.

  9. 50 CFR Figure 11 to Part 679 - Red King Crab Savings Area (RKCSA)

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Red King Crab Savings Area (RKCSA) 11 Figure 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 11 Figure 11 to Part 679—Red King Crab Savings Area (RKCSA) ER15NO99.009...

  10. 50 CFR Figure 11 to Part 679 - Red King Crab Savings Area (RKCSA)

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Red King Crab Savings Area (RKCSA) 11 Figure 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 11 Figure 11 to Part 679—Red King Crab Savings Area (RKCSA) ER15NO99.009...

  11. 50 CFR Figure 11 to Part 679 - Red King Crab Savings Area (RKCSA)

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Red King Crab Savings Area (RKCSA) 11 Figure 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 11 Figure 11 to Part 679—Red King Crab Savings Area (RKCSA) ER15NO99.009...

  12. 50 CFR Figure 11 to Part 679 - Red King Crab Savings Area (RKCSA)

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Red King Crab Savings Area (RKCSA) 11 Figure 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 11 Figure 11 to Part 679—Red King Crab Savings Area (RKCSA) ER15NO99.009...

  13. 50 CFR Figure 11 to Part 679 - Red King Crab Savings Area (RKCSA)

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Red King Crab Savings Area (RKCSA) 11 Figure 11 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 11 Figure 11 to Part 679—Red King Crab Savings Area (RKCSA) ER15NO99.009...

  14. Differential detection of shrimp and crab for food labeling using polymerase chain reaction.

    PubMed

    Taguchi, Hiromu; Watanabe, Satoshi; Temmei, Yusuke; Hirao, Takashi; Akiyama, Hiroshi; Sakai, Shinobu; Adachi, Reiko; Sakata, Kozue; Urisu, Atsuo; Teshima, Reiko

    2011-04-27

    Shrimp and crab are well-known as allergenic ingredients. According to Japanese food allergy labeling regulations, shrimp species (including prawns, crayfishes, and lobsters) and crab species must be differentially declared when ≥10 ppm (total protein) of an allergenic ingredient is present. However, the commercial ELISA tests for the detection of crustacean proteins cannot differentiate between shrimp and crab. Therefore, two methods were developed to discriminate shrimp and crab: a shrimp-PCR method with postamplification digestion and a crab-PCR method that specifically amplifies a fragment of the 16S rRNA gene. The sensitivity and specificity of both PCR methods were verified by experiments using DNA extracted from 15 shrimp species, 13 crab species, krill, mysid, mantis shrimp, other food samples (cephalopod, shellfish, and fish), incurred foods, and commercial food products. Both PCR methods could detect 5 pg of DNA extracted from target species and 50 ng of genomic DNA extracted from incurred foods containing 10 ppm (μg/g) total protein of shrimp or crab. The two PCR methods were considered to be specific enough to separately detect species belonging to shrimp and crab. Although false-positive and false-negative results were obtained from some nontarget crustacean species, the proposed PCR methods, when used in conjunction with ELISA tests, would be a useful tool for confirmation of the validity of food allergy labeling and management of processed food safety for allergic patients. PMID:21395255

  15. Epidemiology of acanthocephalan infections in crabs from the Bahía Blanca Estuary, Argentina.

    PubMed

    La Sala, L F; Perez, A M; Martorelli, S R

    2012-12-01

    This study was conducted in two populations of crabs, Cyrtograpsus angulatus and Neohelice granulata from the Bahía Blanca Estuary, in Argentina, to identify risk factors for infection by the acanthocephalan Profilicollis chasmagnathi and to assess the association between infection and mortality of these hosts. Cyrtograpsus angulatus and N. granulata crabs were sampled seasonally over the course of a year, and spring sampling included collection of dead crabs predated by Olrog's gulls in a nearby breeding colony. Potential risk factors for infection were assessed and the number of cystacanth larvae per crab was counted. In C. angulatus, the odds of infection increased by 7% for each millimetre increase in carapace length, and were nearly 17 times greater in crabs sampled from the Olrog's gull feeding area compared with those sampled from nests in the breeding colony. For every millimetre increase in carapace length in N. granulata, the odds of infection increased by 13% in crabs from the breeding colony, and by 32% in crabs from the feeding area. Mean intensity of infection in N. granulata increased by 16.5% for each additional millimetre of carapace width. The level of parasite aggregation was lowest in the largest C. angulatus and highest in N. granulata predated by Olrog's gull. The results show that host size is the most important factor influencing infection prevalence in both crab species and intensity of infection in N. granulata, and suggest the presence of parasite-induced mortality in the populations studied.

  16. Prevalence and distribution of three protozoan symbionts in blue crab (Callinectes sapidus) populations across Louisiana, USA.

    PubMed

    Rogers, Holly A; Taylor, Sabrina S; Hawke, John P; Anderson Lively, Julie A

    2015-05-11

    Louisiana has one of the largest blue crab (Callinectes sapidus) fisheries in the USA, but little is known about blue crab diseases, parasites, and symbionts in this area. In 2013-2014, large juvenile and adult blue crabs were collected at 4 diverse sites to determine the prevalence of the protozoan symbionts associated with black gill disease (Lagenophrys callinectes), buckshot crabs (Urosporidium crescens), and bitter crab disease (Hematodinium perezi). A high aggregate prevalence of L. callinectes (93.2%) was identified across all seasons at all 4 collection sites regardless of salinity. A moderately low aggregate prevalence of U. crescens (22.4%) was identified across all seasons and sites. Prevalence of U. crescens depended on site salinity, with only 10% of infections detected at sites with <6.3 ppt salinity, and no infections detected at the low salinity site. While L. callinectes and U. crescens are commensal parasites of blue crabs, infections can result in unmarketable and unappealing meat. In the Louisiana fishery, H. perezi has been blamed circumstantially for adult mortalities in the low salinity nearshore fishing grounds. Despite this, H. perezi was not detected in any of the large crabs sampled, even from the low salinity sites. The prevalence data reported here for these 3 protozoans are the first to include blue crabs sampled seasonally at multiple locations along the Louisiana coast over the period of a year.

  17. Giant Robber Crabs Monitored from Space: GPS-Based Telemetric Studies on Christmas Island (Indian Ocean)

    PubMed Central

    Krieger, Jakob; Grandy, Ronald; Drew, Michelle M.; Erland, Susanne; Stensmyr, Marcus C.; Harzsch, Steffen; Hansson, Bill S.

    2012-01-01

    We investigated the navigational capabilities of the world's largest land-living arthropod, the giant robber crab Birgus latro (Anomura, Coenobitidae); this crab reaches 4 kg in weight and can reach an age of up to 60 years. Populations are distributed over small Indo-Pacific islands of the tropics, including Christmas Island (Indian Ocean). Although this species has served as a crustacean model to explore anatomical, physiological, and ecological aspects of terrestrial adaptations, few behavioral analyses of it exist. We used a GPS-based telemetric system to analyze movements of freely roaming robber crabs, the first large-scale study of any arthropod using GPS technology to monitor behavior. Although female robber crabs are known to migrate to the coast for breeding, no such observations have been recorded for male animals. In total, we equipped 55 male robber crabs with GPS tags, successfully recording more than 1,500 crab days of activity, and followed some individual animals for as long as three months. Besides site fidelity with short-distance excursions, our data reveal long-distance movements (several kilometers) between the coast and the inland rainforest. These movements are likely related to mating, saltwater drinking and foraging. The tracking patterns indicate that crabs form route memories. Furthermore, translocation experiments show that robber crabs are capable of homing over large distances. We discuss if the search behavior induced in these experiments suggests path integration as another important navigation strategy. PMID:23166774

  18. Giant robber crabs monitored from space: GPS-based telemetric studies on Christmas Island (Indian Ocean).

    PubMed

    Krieger, Jakob; Grandy, Ronald; Drew, Michelle M; Erland, Susanne; Stensmyr, Marcus C; Harzsch, Steffen; Hansson, Bill S

    2012-01-01

    We investigated the navigational capabilities of the world's largest land-living arthropod, the giant robber crab Birgus latro (Anomura, Coenobitidae); this crab reaches 4 kg in weight and can reach an age of up to 60 years. Populations are distributed over small Indo-Pacific islands of the tropics, including Christmas Island (Indian Ocean). Although this species has served as a crustacean model to explore anatomical, physiological, and ecological aspects of terrestrial adaptations, few behavioral analyses of it exist. We used a GPS-based telemetric system to analyze movements of freely roaming robber crabs, the first large-scale study of any arthropod using GPS technology to monitor behavior. Although female robber crabs are known to migrate to the coast for breeding, no such observations have been recorded for male animals. In total, we equipped 55 male robber crabs with GPS tags, successfully recording more than 1,500 crab days of activity, and followed some individual animals for as long as three months. Besides site fidelity with short-distance excursions, our data reveal long-distance movements (several kilometers) between the coast and the inland rainforest. These movements are likely related to mating, saltwater drinking and foraging. The tracking patterns indicate that crabs form route memories. Furthermore, translocation experiments show that robber crabs are capable of homing over large distances. We discuss if the search behavior induced in these experiments suggests path integration as another important navigation strategy.

  19. Cymo melanodactylus crabs slow progression of white syndrome lesions on corals

    NASA Astrophysics Data System (ADS)

    Pollock, F. J.; Katz, S. M.; Bourne, D. G.; Willis, B. L.

    2013-03-01

    Predation on coral tissue by the crab Cymo melanodactylus has been hypothesized to contribute to tissue loss caused by white syndromes (WS) in acroporid corals. Here, we demonstrate that transplanting C. melanodactylus crabs from WS-infected Acropora colonies onto healthy coral fragments in controlled aquarium experiments does not result in WS transmission over a 21-day experimental period. Furthermore, progression of WS lesions was three times more rapid on corals with all C. melanodactylus crabs removed than on those with crabs (2.28 ± 0.21 vs. 0.74 ± 0.22 cm/day, respectively); thus, crabs slow WS disease progression under experimental conditions. In choice experiments, C. melanodactylus crabs were strongly attracted to corals with WS lesions, with 87 % of crabs migrating to WS fragments versus 3 % to healthy fragments. The strong attraction of C. melanodactylus to WS-infected corals and their ability to significantly reduce lesion progression rates suggest a mechanism whereby these coral-dwelling crabs could mitigate the effects of WS diseases on reefs.

  20. Folk classification of the crabs and swimming crabs (Crustacea – Brachyura) of the Mamanguape river estuary, Northeastern – Brazil

    PubMed Central

    Ferreira, Emmanoela N; da S Mourão, José; Rocha, Pollyana D; Nascimento, Douglas M; da S Q Bezerra, Dandara Monalisa Mariz

    2009-01-01

    Background Folk taxonomy is a sub-area of ethnobiology that study the way of how traditional communities classify, identify and name their natural resources. The work present was undertaken in two traditional communities (Barra de Mamanguape and Tramataia). The objective of this study was investigate the ethnobiological classification of the local crabs and swimming crabs used by the crustaceous gatherers of the Mamanguape River Estuary (MRE), Paraíba State, Brazil. Methods The methodology used here involved a combination of qualitative methods (open interviews, semi-structured interviews, direct observations, guided tours, surveys, and interviews in synchronic and diachronic situations that crossed-checked and repeated identifications) and quantitative methods (Venn diagram). A total of 32 men and women were interviewed in the two communities. Specimens of the local crustaceans were collected and identified by the harvesters themselves, subsequently fixed in formalin, conserved in 70% ethyl alcohol, identified using appropriate specialized literature, and then deposited in the laboratory of the Zoology Department of the University State of Paraiba. Results The crustaceous gatherers we studied were observed to group crustaceans according to their similarities and differences, producing a hierarchical classification system containing four levels of decreasing taxonomic order: unique beginner, life-form, generic, and specific. A sequential and/or semantic system classification system that is used to classify the ontogeny of the female swimming crab was also identified. Of the nine folk generics identified, 44.5% were monotypic. 55.5% were polytypic and were subdivided into 15 folk specifics. An identification key was elaborated with the data obtained about the folk polytypics generics. Conclusion The detailed knowledge concerning the crabs and swimming crabs revealed by the MRE crustaceous gatherers demonstrates that these people detain a vast knowledge concerning