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Sample records for scallop chlamys farreri

  1. Transcriptome sequencing of Zhikong scallop (Chlamys farreri and comparative transcriptomic analysis with Yesso scallop (Patinopecten yessoensis.

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    Shan Wang

    Full Text Available BACKGROUND: Bivalves play an important role in the ecosystems they inhabit and represent an important food source all over the world. So far limited genetic research has focused on this group of animals largely due to the lack of sufficient genetic or genomic resources. Here, we performed de novo transcriptome sequencing to produce the most comprehensive expressed sequence tag resource for Zhikong scallop (Chlamys farreri, and conducted the first transcriptome comparison for scallops. RESULTS: In a single 454 sequencing run, 1,033,636 reads were produced and then assembled into 26,165 contigs. These contigs were then clustered into 24,437 isotigs and further grouped into 20,056 isogroups. About 47% of the isogroups showed significant matches to known proteins based on sequence similarity. Transcripts putatively involved in growth, reproduction and stress/immune-response were identified through Gene ontology (GO and KEGG pathway analyses. Transcriptome comparison with Yesso scallop (Patinopecten yessoensis revealed similar patterns of GO representation. Moreover, 38 putative fast-evolving genes were identified through analyzing the orthologous gene pairs between the two scallop species. More than 46,000 single nucleotide polymorphisms (SNPs and 350 simple sequence repeats (SSRs were also detected. CONCLUSION: Our study provides the most comprehensive transcriptomic resource currently available for C. farreri. Based on this resource, we performed the first large-scale transcriptome comparison between the two scallop species, C. farreri and P. yessoensis, and identified a number of putative fast-evolving genes, which may play an important role in scallop speciation and/or local adaptation. A large set of single nucleotide polymorphisms and simple sequence repeats were identified, which are ready for downstream marker development. This transcriptomic resource should lay an important foundation for future genetic or genomic studies on C. farreri.

  2. The immunomodulation of acetylcholinesterase in zhikong scallop Chlamys farreri.

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    Xiaowei Shi

    Full Text Available BACKGROUND: Acetycholinesterase (AChE; EC 3.1.1.7 is an essential hydrolytic enzyme in the cholinergic nervous system, which plays an important role during immunomodulation in vertebrates. Though AChEs have been identified in most invertebrates, the knowledge about immunomodulation function of AChE is still quite meagre in invertebrates. METHODOLOGY: A scallop AChE gene was identified from Chlamys farreri (designed as CfAChE, and its open reading frame encoded a polypeptide of 522 amino acids. A signal peptide, an active site triad, the choline binding site and the peripheral anionic sites (PAS were identified in CfAChE. The recombinant mature polypeptide of CfAChE (rCfAChE was expressed in Pichia pastoris GS115, and its activity was 71.3±1.3 U mg(-1 to catalyze the hydrolysis of acetylthiocholine iodide. The mRNA transcripts of CfAChE were detected in haemocytes, hepatopancreas, adductor muscle, mantle, gill, kidney and gonad, with the highest expression level in hepatopancreas. The relative expression level of CfAChE mRNA in haemocytes was both up-regulated after LPS (0.5 mg mL(-1 and human TNF-α (50 ng mL(-1 stimulations, and it reached the highest level at 12 h (10.4-fold, P<0.05 and 1 h (3.2-fold, P<0.05, respectively. After Dichlorvos (DDVP (50 mg L(-1 stimulation, the CfAChE activity in the supernatant of haemolymph decreased significantly from 0.16 U mg(-1 at 0 h to 0.03 U mg(-1 at 3 h, while the expression level of lysozyme in the haemocytes was up-regulated and reached the highest level at 6 h, which was 3.0-fold (P<0.05 of that in the blank group. CONCLUSIONS: The results collectively indicated that CfAChE had the acetylcholine-hydrolyzing activity, which was in line with the potential roles of AChE in the neuroimmune system of vertebrates which may help to re-balance the immune system after immune response.

  3. Cytological comparison of gametogenesis of scallops, Argopecten irradians and Chlamys farreri

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    Dong, Xin-Hong; Liu, Bao-Zhong; Wu, Chang-Gong; Xiang, Jian-Hai

    2002-09-01

    Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri, where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it.

  4. Fertilization and cytogenetic examination of interspecific reciprocal hybridization between the scallops, Chlamys farreri and Mimachlamys nobilis.

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    Huang, Xiaoting; Bi, Ke; Hu, Liping; Sun, Yan; Lu, Wei; Bao, Zhenmin

    2011-01-01

    Crossbreeding is a powerful tool for improving productivity and profitability in aquaculture. We conducted a pilot study of an artificial cross between two important cultivated scallops in China, Chlamys farreri and Mimachlamys nobilis, to test the feasibility of interspecific hybridization. Reciprocal hybridization experiments were performed using a single-pair mating strategy (M. nobilis ♀ × C. farreri ♂ and C. farreri ♀ × M. nobilis ♂). The fertilization of each pair was tracked using fluorescence staining of the gametes, and the chromosomes of the F1 hybrid larvae were examined via conventional karyotyping and genomic in situ hybridization (GISH). We observed moderate fertilization success in both interspecific crosses, although the overall fertilization was generally less rapid than that of intraspecific crosses. Conventional karyotyping showed that 70.4% of the viable F1 larvae in M. nobilis ♀ × C. farreri ♂ and 55.4% in C. farreri ♀ × M. nobilis ♂ comprised hybrid karyotypes (2n = 35 = 6m+5sm+11st+13t), and the results were further confirmed by GISH. Interestingly, we detected a few F1 from the M. nobilis ♀ × C. farreri ♂ cross that appeared to have developed gynogenetically. In addition, chromosome fragmentations, aneuploids and allopolyploids were observed in some F1 individuals. Our study presents evidence that the artificial cross between M. nobilis and C. farreri is experimentally possible. Further investigations of the potential heterosis of the viable F1 offspring at various developmental stages should be conducted to obtain a comprehensive evaluation of the feasibility of crossbreeding between these two scallop species.

  5. Association of myostatin variants with growth traits of Zhikong scallop ( Chlamys farreri)

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    Fu, Qiang; Guo, Huihui; Feng, Liying; Li, Xue; Zhang, Lingling; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2016-02-01

    Scallop is a popular sea food and an important aquaculture shellfish. Identification of genes and genetic variants relating to scallop growth could benefit high-yielding scallop breeding. Myostatin ( MSTN) is a conservative regulator of muscle growth, and has become one of the most important target genes for genetic improvement of the production of farmed animals. In this study, four single nucleotide polymorphisms (SNPs) were identified in the 5' flanking region of MSTN gene ( CfMSTN) in Zhikong scallop ( Chlamys farreri). The association of these SNPs with scallop growth traits, including shell length, shell height, body weight and striated muscle weight was analyzed. The SNP g-1162Gscallops showed significantly higher trait values than those of GT type, and the GG type individuals exhibited median values. On the contrary, significantly more CfMSTN transcripts were detected in the striated muscle of GT type scallops than in those of TT and GG type ones. Our results suggested that CfMSTN might regulate the scallop muscle growth negatively, and SNP g-1162Gscallop.

  6. Assessing PAHs pollution in Qingdao coastal area (China) by the combination of chemical and biochemical responses in scallops, Chlamys farreri.

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    Jin, Qian; Pan, Luqing; Liu, Dong; Hu, Fengxiao; Xiu, Meng

    2014-12-15

    The PAHs concentrations in seawater and tissues from the scallop Chlamys farreri were detected in three sites in Qingdao, China in 2011. The PAHs concentrations in seawater ranged from 25.32 ng/L to 314.62 ng/L. There were significant differences (ppollution status in Qingdao, China. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Construction of bacterial artificial chromosome libraries for Zhikong Scallop Chlamys farreri

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    Zhang, Yang; Zhang, Xiaojun; Scheuring, Chantel F.; Zhang, Hongbin; Li, Fuhua; Xiang, Jianhai

    2008-05-01

    Two Large-insert genomic bacterial artificial chromosome (BAC) libraries of Zhikong scallop Chlamys farreri were constructed to promote our genetic and genomic research. High-quality megabase-sized DNA was isolated from the adductor muscle of the scallop and partially digested by BamH I and Mbo I, respectively. The BamH I library consisted of 53 760 clones while the Mbo I library consisted of 7 680clones. Approximately 96 % of the clones in BamH I library contained nuclear DNA inserts in average size of 100 kb, providing a coverage of 5.3 haploid genome equivalents. Similarly, the Mbo I library with an average insert of 145 kb and no insert-empty clones, thus providing a genome coverage of 1.1 haploid genome equivalents.

  8. Expression pattern of phb2 and its potential function in spermatogenesis of scallop ( Chlamys farreri)

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    Han, Tiantian; Ma, Xiaoshi; Liang, Shaoshuai; Gao, Beibei; Zhang, Zhifeng

    2015-12-01

    Prohibitin (PHB) participates in several biological processes including apoptosis, transcription regulation and suppression of cell proliferation in mammals. In this study, we cloned the full-length cDNA of prohibitin 2 ( Cf-phb2) from the testis of scallop ( Chlamys farreri). The deduced amino acid sequence presented a characteristic of PHB family with the PHB domain, and clustered with PHB2 of other species. Temporal and spatial expression of Cf-phb2 in testis during the reproductive cycle was detected by quantitative real-time PCR (qRT-PCR) and in situ hybridization. The expression of Cf-phb2 in the testis increased when testis developed from the resting stage to mature stage. The mRNA abundance of Cf-phb2 was the highest at mature stage, which was about 15-fold higher than that at proliferative stage. The expression of Cf-phb2 could be detected by in situ hybridization in all types of germ cells in testis, including spermatogonia, spermatocytes, spermatids and spermatozoa. The intensity of the signal increased with the spermatogenesis and was the highest in spermatids, which suggested that CF-PHB2 might affect the spermatogenesis of C. farreri.

  9. Molecular cloning and characterization of SoxB2 gene from Zhikong scallop Chlamys farreri

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    He, Yan; Bao, Zhenmin; Guo, Huihui; Zhang, Yueyue; Zhang, Lingling; Wang, Shi; Hu, Jingjie; Hu, Xiaoli

    2013-11-01

    The Sox proteins play critical roles during the development of animals, including sex determination and central nervous system development. In this study, the SoxB2 gene was cloned from a mollusk, the Zhikong scallop ( Chlamys farreri), and characterized with respect to phylogeny and tissue distribution. The full-length cDNA and genomic DNA sequences of C. farreri SoxB2 ( Cf SoxB2) were obtained by rapid amplification of cDNA ends and genome walking, respectively, using a partial cDNA fragment from the highly conserved DNA-binding domain, i.e., the High Mobility Group (HMG) box. The full-length cDNA sequence of Cf SoxB2 was 2 048 bp and encoded 268 amino acids protein. The genomic sequence was 5 551 bp in length with only one exon. Several conserved elements, such as the TATA-box, GC-box, CAAT-box, GATA-box, and Sox/sry-sex/testis-determining and related HMG box factors, were found in the promoter region. Furthermore, real-time quantitative reverse transcription PCR assays were carried out to assess the mRNA expression of Cf SoxB 2 in different tissues. SoxB2 was highly expressed in the mantle, moderately in the digestive gland and gill, and weakly expressed in the gonad, kidney and adductor muscle. In male and female gonads at different developmental stages of reproduction, the expression levels of Cf SoxB2 were similar. Considering the specific expression and roles of SoxB 2 in other animals, in particular vertebrates, and the fact that there are many pallial nerves in the mantle, cerebral ganglia in the digestive gland and gill nerves in gill, we propose a possible essential role in nervous tissue function for Sox B 2 in C. farreri.

  10. Development of 101 novel EST-derived single nucleotide polymorphism markers for Zhikong scallop ( Chlamys farreri)

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    Li, Jiqin; Bao, Zhenmin; Li, Ling; Wang, Xiaojian; Wang, Shi; Hu, Xiaoli

    2013-09-01

    Zhikong scallop ( Chlamys farreri) is an important maricultured species in China. Many researches on this species, such as population genetics and QTL fine-mapping, need a large number of molecular markers. In this study, based on the expressed sequence tags (EST), a total of 300 putative single nucleotide polymorphisms (SNPs) were selected and validated using high resolution melting (HRM) technology with unlabeled probe. Of them, 101 (33.7%) were found to be polymorphic in 48 individuals from 4 populations. Further evaluation with 48 individuals from Qingdao population showed that all the polymorphic loci had two alleles with the minor allele frequency ranged from 0.046 to 0.500. The observed and expected heterozygosities ranged from 0.000 to 0.925 and from 0.089 to 0.505, respectively. Fifteen loci deviated significantly from Hardy-Weinberg equilibrium and significant linkage disequilibrate was detected in one pair of markers. BLASTx gave significant hits for 72 of the 101 polymorphic SNP-containing ESTs. Thirty four polymorphic SNP loci were predicted to be non-synonymous substitutions as they caused either the change of codons (33 SNPs) or pretermination of translation (1 SNP). The markers developed can be used for the population studies and genetic improvement on Zhikong scallop.

  11. The modulation of catecholamines on immune response of scallop Chlamys farreri under heat stress.

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    Zhang, Huan; Zhou, Zhi; Yue, Feng; Wang, Lingling; Yang, Chuanyan; Wang, Mengqiang; Song, Linsheng

    2014-01-01

    Catecholamines (CAs) play key roles in mediating the physiological responses to various stresses. In the present study, the expression of CA-related genes were examined in the hemocytes of scallop Chlamys farreri under heat stress, and several immune or metabolism-related parameters were investigated after heat stress and adrenoceptor antagonist stimulation. After the scallops were cultured at 28°C, the mRNA expression level of dopa decarboxylase (CfDDC) and α-adrenoceptor (CfαAR) increased significantly (P<0.01), whereas that of monoamine oxidase (CfMAO) was down-regulated in the first 6h (P<0.05), and then up-regulated to the maximum level at 24h (P<0.01). In the hemocytes of scallops injected with adrenoceptor antagonist, the expression levels of peptidoglycan-recognition protein (CfPGRP-S1) and C-type lectin (CfLec-1) began to increase significantly at 2 and 3h post propranolol and high temperature treatment, respectively (P<0.01). While the up-regulation of heat shock protein 70 (CfHSP70) post heat stress was significantly inhibited by prazosin injection (P<0.01), and that of hexokinase (CfHK) was inhibited by both prazosin and propranolol injection (P<0.01). Moreover, the remarkable increase of relative specific activity of SOD in the hemolymph post heat stress (P<0.01) was further up-regulated early after prazosin or propranolol injection (P<0.01), while that of the relative anti-bacterial ability was down-regulated by prazosin or propranolol treatment (P<0.01). These results collectively indicated that the catecholaminergic neuroendocrine system in scallop could be activated by heat stress to release CAs, which subsequently modulated the immune response and energy metabolism via α- and β-adrenoceptors. Copyright © 2013. Published by Elsevier Inc.

  12. A BAC-based physical map of Zhikong scallop (Chlamys farreri Jones et Preston.

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    Xiaojun Zhang

    Full Text Available Zhikong scallop (Chlamys farreri is one of the most economically important aquaculture species in China. Physical maps are crucial tools for genome sequencing, gene mapping and cloning, genetic improvement and selective breeding. In this study, we have developed a genome-wide, BAC-based physical map for the species. A total of 81,408 clones from two BAC libraries of the scallop were fingerprinted using an ABI 3130xl Genetic Analyzer and a fingerprinting kit developed in our laboratory. After data processing, 63,641 (∼5.8× genome coverage fingerprints were validated and used in the physical map assembly. A total of 3,696 contigs were assembled for the physical map. Each contig contained an average of 10.0 clones, with an average physical size of 490 kb. The combined total physical size of all contigs was 1.81 Gb, equivalent to approximately 1.5 fold of the scallop haploid genome. A total of 10,587 BAC end sequences (BESs and 167 markers were integrated into the physical map. We evaluated the physical map by overgo hybridization, BAC-FISH (fluorescence in situ hybridization, contig BAC pool screening and source BAC library screening. The results have provided evidence of the high reliability of the contig physical map. This is the first physical map in mollusc; therefore, it provides an important platform for advanced research of genomics and genetics, and mapping of genes and QTL of economical importance, thus facilitating the genetic improvement and selective breeding of the scallop and other marine molluscs.

  13. Importance of kelp-derived organic carbon to the scallop Chlamys farreri in an integrated multi-trophic aquaculture system

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    Xu, Qiang; Gao, Fei; Yang, Hongsheng

    2016-03-01

    Bivalves and seaweeds are important cleaners that are widely used in integrated multi-trophic aquaculture (IMTA) systems. A beneficial relationship between seaweed and bivalve in the seaweed-based IMTA system has been confirmed, but the trophic importance of seaweed-derived particulate organic materials to the co-cultured bivalve is still unclear. We evaluated the trophic importance of the kelp Saccharina japonica to the co-cultured scallop Chlamys farreri in a typical IMTA farm in Sungo Bay (Weihai, North China). The dynamics of detritus carbon in the water were monitored during the culturing period. The proportion of kelp-derived organic matter in the diet of the co-cultured scallop was assessed via the stable carbon isotope method. Results showed that the detritus carbon in the water ranged from 75.52 to 265.19 μg/L, which was 25.6% to 73.8% of total particulate organic carbon (TPOC) during the study period. The amount of detritus carbon and its proportion in the TPOC changed throughout the culture cycle of the kelp. Stable carbon isotope analysis showed that the cultured scallop obtained 14.1% to 42.8% of its tissue carbon from the kelp, and that the percentages were closely correlated with the proportion of detritus carbon in the water ( F =0.993, P= 0.003). Evaluation showed that for 17 000 tons (wet weight) of annual scallop production, the kelp contributed about 139.3 tons of carbon (535.8 tons of dry mass). This confirms that cultured kelp plays a similar trophic role in IMTA systems as it does in a natural kelp bed. It is a major contributor to the detritus pool and supplies a vital food source to filter-feeding scallops in the IMTA system, especially during winter and early spring when phytoplankton are scarce.

  14. Multi-biomarker approach in the scallop Chlamys farreri to assess PAHs pollution in Qingdao coastal areas of China.

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    Pan, Luqing; Zhang, Mengyu; Jin, Qian; Ji, Rongwang

    2017-11-15

    A multi-biomarker approach was conducted in the scallop Chlamys farreri from three sites, denoted here as S1, S2, and S3, in Qingdao coastal areas of China in March, June, September and December 2014 to assess pollution from polycyclic aromatic hydrocarbons (PAHs) and to select appropriate biomarkers. A suite of biological responses of the gills and digestive glands of the scallops was assayed, including: (i) phase I detoxification enzymes of 7-ethoxyresorufin-O-deethylase (EROD), epoxide hydrolase (EH), and dihydrodiol dehydrogenase (DD) and phase II detoxification enzymes of glutathione-S-transferase (GST) and sulfotransferase (SULT); (ii) antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx); (iii) oxidative damage parameters: lipid peroxidation (LPO) expressed by malondialdehyde (MDA) contents, protein carbonylation (PC) and DNA damage (F value); and (iv) the metabolism-related genes of EH, DD, GST, SULT and SOD. Simultaneously, the concentrations of total PAHs along with 16 types of PAHs previously identified by the US Environmental Protection Agency (USEPA) and environmental parameters, including temperature and salinity together with pH, were measured. Using Principle Component Analysis (PCA), it was revealed that S2 was the most PAH-contaminated site, while S1 was identified as the least PAH-polluted site, which was consistent with the results utilizing the Biomarker Response Index (BRI); in other words, the biological health status of S2 was worse than S1 and S3. Moreover, the most suitable biomarkers to assess PAH pollution in Qingdao coastal areas proved to be DD mRNA expression and the F value in both the gills and digestive glands for the total PAHs, DD activity and PC contents or PC and MDA contents in the gills or digestive glands for 5 + 6 rings PAHs and DD mRNA expression in both the gills and digestive glands for 2 + 3 rings and 4 rings PAHs. Moreover, this study highlighted the possible use of the

  15. Characterization, expression and function analysis of DAX1 gene of scallop ( Chlamys farreri jones and preston 1904) during its gametogenesis

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    Li, Hailong; Liu, Jianguo; Huang, Xiaoting; Wang, Dan; Zhang, Zhifeng

    2014-08-01

    DAX1, a member of nuclear receptor superfamily, has a function in the sex determination and gonadal differentiation of several vertebrate species. However, little information about DAX1 of invertebrates is available. Here we cloned a homolog of scallop ( Chlamys farreri Jones and Preston 1904) dax1, Cf-dax1, and determined its expression characteristics at mRNA and protein levels. The cDNA sequence of Cf-dax1 was 2093 bp in length, including 1404 bp open reading frame (ORF) encoding 467 amino acids. Unlike those of vertebrates, no conserved LXXLL-related motif was found in the putative DNA binding region of Cf-DAX1. Fluorescence in situ hybridization showed that Cf-dax1 located on the short arm of a pair of subtelocentric chromosomes. Tissue distribution analysis using semi-quantitative RT-PCR revealed that Cf-dax1 expressed widely in adult scallop tissues, with the highest expression level found in adductor muscle, moderate level in mantle, gill and testis, and low level in kidney, ovary and hepatopancreas. The result of quantitative real-time PCR indicated that the expression of Cf-dax1 was significantly higher ( Pgametogenesis of bivalves.

  16. The modulation of catecholamines to the immune response against bacteria Vibrio anguillarum challenge in scallop Chlamys farreri.

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    Zhou, Zhi; Wang, Lingling; Shi, Xiaowei; Zhang, Huan; Gao, Yang; Wang, Mengqiang; Kong, Pengfei; Qiu, Limei; Song, Linsheng

    2011-12-01

    Catecholamines are pivotal signal molecules in the neuroendocrine-immune regulatory network, and implicated in the modulation of immune response. In the present study, the activities of some immune-related enzymes and the concentration of catecholamines were determined in circulating haemolymph of scallops Chlamys farreri after bacteria Vibrio anguillarum challenge. The activities of superoxide dismutase (SOD), catalase (CAT) and lysozyme (LYZ) increased significantly and reached 610 U mg(-1) at 12 h, 37.6 U mg(-1) at 6 h and 261.5 U mg(-1) at 6 h after bacteria challenge, respectively. The concentration of norepinephrine, epinephrine and dopamine also increased significantly and reached 114.9 ng mL(-1) at 12 h, 86.9 ng mL(-1) at 24 h and 480.4 pg mL(-1) at 12 h after bacteria challenge, respectively. Meanwhile, the activities of these immune-related enzymes in haemolymph were monitored in those scallops which were challenged by bacteria V. anguillarum and stimulated simultaneously with norepinephrine, epinephrine and adrenoceptor antagonist. The injection of norepinephrine and epinephrine repressed significantly the induction of bacteria challenge on the activities of immune-related enzymes, and they were reduced to about half of that in the control groups. The blocking of α and β-adrenoceptor by antagonist only repressed the increase of CAT and LYZ activities significantly, while no significant effect was observed on the increase of SOD activities. The collective results indicated that scallop catecholaminergic neuroendocrine system could be activated by bacteria challenge to release catecholamines after the immune response had been triggered, and the immune response against bacteria challenge could been negatively modulated by norepinephrine, epinephrine, and adrenoceptor antagonist. This information is helpful to further understand the immunomodulation of catecholamines in scallops. Copyright © 2011. Published by Elsevier Ltd.

  17. An investigation of endocrine disrupting effects and toxic mechanisms modulated by benzo[a]pyrene in female scallop Chlamys farreri

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    Tian, Shuangmei; Pan, Luqing, E-mail: panlq@ouc.edu.cn; Sun, Xiaohua

    2013-11-15

    Highlights: •B[a]P disturbed progesterone, 17β-estradiol and testosterone production in scallop. •B[a]P inhibited 3β-HSD, CYP17 and 17β-HSD expression after a 10-day exposure. •B[a]P of lower dose elevated AHR-CYP1A expression but high dose B[a]P inhibited them. •ER and vitellogenin transcription was consistent with AHR after B[a]P exposure. •B[a]P exposure induced relatively developmental delay and impairment of ovary. -- Abstract: The purpose of this study was to investigate the endocrine disrupting effects induced by benzo[a]pyrene (B[a]P) and explore the underlying mechanisms in mollusks. In this study, sexually mature female Chlamys farreri were exposed to benzo[a]pyrene for 10 days at four different concentrations as 0, 0.025, 0.5 and 10 μg/L. Sex steroids were identified and quantified by electrochemiluminescence immunoassay (ECLIA) method and results showed that exposure to B[a]P exerts great suppression on 17β-estradiol, testosterone production and disrupts progesterone levels in ovary. Transcription of genes were detected and measured by real-time RT-PCR. It showed that at day 10 B[a]P inhibited 3β-HSD, CYP17 and 17β-HSD mRNA expression in a dose-dependent manner, which suggests that they could be potential targets of B[a]P that disrupt steroidogenic machinery. Moreover, 0.025 μg/L B[a]P activated transcription of aryl hydrocarbon receptor (AHR), AHR nuclear translocator (ARNT), CYP1A1 and estrogen receptor (ER), while 10 μg/L B[a]P suppressed all of them. The consistency of their responses to B[a]P exposure implies that AHR action may be involved in invertebrate CYP regulation and ER transcription despite of unknown mechanisms. Additionally, B[a]P exposure could induce ovarian impairment and developmental delay in C. farreri. Overall, sensitivity of C. farreri to endocrine disruption and toxicity suggests that C. farreri is a suitable species for study of endocrine-disrupting effects in marine invertebrates. This study will form a

  18. The comparative proteomics analysis revealed the modulation of inducible nitric oxide on the immune response of scallop Chlamys farreri.

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    Sun, Zhibin; Jiang, Qiufen; Wang, Lingling; Zhou, Zhi; Wang, Mengqiang; Yi, Qilin; Song, Linsheng

    2014-10-01

    Nitric oxide (NO) is an important gasotransmitter which plays a key role on the modulation of immune response in all vertebrates and invertebrates. In the present study, the modulation of inducible NO on immune response of scallop Chlamys farreri was investigated via proteomic analysis. Total proteins from hepatopancreas of scallops treated with lipopolysaccharide (LPS) and/or the inhibitor of vertebrate inducible NO synthase (S-methylisothiourea sulfate, SMT) for 12 h were analyzed via 2-D PAGE and ImageMaster 2D Platinum. There were 890, 1189 and 1046 protein spots detected in the groups treated by phosphate buffered saline (PBS), LPS and LPS+SMT, respectively, and 26 differentially expressed protein spots were identified among them. These proteins were annotated with binding or catalytic activity, and most of them were involved in metabolic or cellular processes. Some immune-related or antioxidant-related molecules such as single Ig IL-1-related receptor, guanine nucleotide-binding protein subunit beta-like protein and peroxiredoxin were identified, and the changes of their expression levels in LPS group were intensified significantly after adding SMT. The decreased expression level of tyrosinase and increased level of glutathione S-transferase 4 in LPS group were diametrically reversed by appending SMT. Moreover, interferon stimulated exonuclease gene 20-like protein and copper chaperone for superoxide dismutase were only induced by LPS+SMT stimulation but not by LPS stimulation. These data indicated that NO could modulate many immunity processes in scallop, such as NF-κB transactivation, cytoskeleton reorganization and other pivotal processes, and it was also involved in the energy metabolism, posttranslational modification, detoxification and redox balance during the immune response. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Changes in global DNA methylation intensity and DNMT1 transcription during the aging process of scallop Chlamys farreri

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    Lian, Shanshan; He, Yan; Li, Xue; Zhao, Bosong; Hou, Rui; Hu, Xiaoli; Zhang, Lingling; Bao, Zhenmin

    2015-08-01

    DNA methylation is an important epigenetic regulatory mechanism that influences genomic stability, gene activation, X-chromosome inactivation and other factors. A change in DNA methylation is usually associated with aging and cellular senescence. DNA methyltransferase 1 (DNMT1) is the most abundant DNA methyltransferase, and it plays an important role in maintaining the established methylation pattern during DNA replication in vertebrates. Although the effect of aging on DNA methylation has been well studied in vertebrates, little research has been conducted in invertebrates, especially in marine bivalves. In this study, we examined global DNA methylation levels in four groups of adult Zhikong scallop Chlamys farreri at different ages. The results showed that both the age and tissue type had a strong effect on the DNA methylation. In addition, a significant decrease in DNA methylation with aging (1-4 years) can be detected in mantle, kidney and hepatopancreas. We further measured the change in DNMT1 transcript abundance using quantitative reverse transcription PCR (qRT-PCR), which revealed that DNMT1 transcription significantly decreased with aging in mantle and hepatopancreas and strongly correlated with DNA methylation ( R = 0.72). Our data provided greater insight into the aging-related decline of DNA methylation, which could aid in gaining a better understanding of the relationship between DNA methylation and the aging process in bivalve mollusks.

  20. Survival, growth and immune activity of scallop Chlamys farreri cultured at different depths in Haizhou Bay (Yellow Sea, China) during hot season

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    Yu, Zonghe; Yang, Hongsheng; Liu, Baozhong; Xing, Kun; Zhang, Libin; Xu, Qiang

    2010-05-01

    Survival, growth and immune response of the scallop, Chlamys farreri, cultured in lantern nets at five different depths (2, 5, 10, 15, and 20 m below the sea surface) were studied in Haizhou Bay during the hot season (summer and autumn) of 2007. Survival and growth rates were quantified bimonthly. Immune activities in hemolymph (superoxide dismutase (SOD) and acid phosphatase (ACP)) were measured to evaluate the health of scallops at the end of the study. Environmental parameters at the five depths were also monitored during the experiment. Mortalities mainly occurred during summer. Survival of scallops suspended at 15 m (78.0%) and 20 m (86.7%) was significantly higher than at 2 m (62.9%), 5 m (60.8%) or 10 m (66.8%) at the end of the study. Mean shell height grew significantly faster at 10 m (205.0 μm/d) and 20 m (236.9 μm/d) than at 2, 5 or 15 m in summer (July 9 to September 1); however, shell growth rate at 20 m was significantly lower than at the other four depths in autumn (September 2 to November 6). In contrast to summer, scallops at 5 m grew faster (262.9 μm/d) during autumn. The growth of soft tissue at different depths showed a similar trend to the shell. Growth rates of shell height and soft tissue were faster in autumn than in summer, with the exception of shell height at 20 m. SOD activity of scallops increased with depth, and ACP activity was significantly higher at 15 and 20 m than at other depths, which suggests that scallops were healthier near the bottom. Factors explaining the depth-related mortality and growth of scallops are also discussed. We conclude that the mass mortality of scallop, C. farreri, during summer can be prevented by moving the culture area to deeper water and yield can be maximized by suspending the scallops in deep water during summer and then transferring them to shallow water in autumn.

  1. Application of SSH and quantitative real time PCR to construction of gene expression profiles from scallop Chlamys farreri in response to exposure to tetrabromobisphenol A.

    Science.gov (United States)

    Gong, Xiaoli; Pan, Luqing; Miao, Jingjing; Liu, Na

    2012-11-01

    TBBPA-induced genes were identified using suppression subtractive hybridization (SSH) from Chlamys farreri. A total of 203 and 44 clones from SSH forward and reverse library were respectively obtained including cellular process, immune system process, response to stimulus, metabolic process and signaling etc. Differential gene expressions were compared between scallops from control and TBBPA treatment groups (400 μg/L, 15 days) using quantitative real time RT-PCR. For further research, eight significant genes expression from scallops exposed to TBBPA (0; 100; 200; 400 μg/L) sampling at 0, 1, 3, 6 and 15 days, were utilized for Q-RT-PCR. The results revealed that the expression level of most selected cDNAs was dominantly up-regulated or down-regulated in the TBBPA-induced scallops. These findings provide basic genomic information of the bivalve and the selected genes may be the potential molecular biomarkers for TBBPA pollution in aquatic environment. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  2. Development of a monoclonal antibody specific to granulocytes and its application for variation of granulocytes in scallop Chlamys farreri after acute viral necrobiotic virus (AVNV) infection.

    Science.gov (United States)

    Lin, Tingting; Xing, Jing; Sheng, Xiuzhen; Tang, Xiaoqian; Zhan, Wenbin

    2011-06-01

    A monoclonal antibody (MAb 6H7) specific to granulocytes of scallop Chlamys farreri was produced by immunising mice with separated granulocytes as an antigen. Characterised using a flow cytometric immunofluorescence assay, MAb 6H7 reacted to granulocytes by 87.1% of total positive haemocytes. At the ultrastructural level, MAb 6H7 demonstrated epitope in cytoplasmic granules of granulocytes. Western blotting analysis indicated that a peptide of 155 kDa was recognised by MAb 6H7. It was therefore used to investigate granulocyte variation in C. farreri after acute viral necrobiotic virus (AVNV) infection using an enzyme-linked immunosorbent assay. The result illustrated that granulocytes varied greatly by AVNV infection, and their amount significantly increased on day 1 post-injection, then decreased on days 2, 3 and 4, thereafter, rebounded and approached to a second peak on day 6, finally went down gradually to the control level on day 8. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. A C1q domain containing protein from scallop Chlamys farreri serving as pattern recognition receptor with heat-aggregated IgG binding activity.

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    Leilei Wang

    Full Text Available BACKGROUND: The C1q domain containing (C1qDC proteins refer to a family of all proteins that contain the globular C1q (gC1q domain, and participate in a series of immune responses depending on their gC1q domains to bind a variety of self and non-self binding ligands. METHODOLOGY: In the present study, the mRNA expression patterns, localization, and activities of a C1qDC protein from scallop Chlamys farreri (CfC1qDC were investigated to understand its possible functions in innate immunity. The relative expression levels of CfC1qDC mRNA in hemocytes were all significantly up-regulated after four typical PAMPs (LPS, PGN, β-glucan and polyI:C stimulation. During the embryonic development of scallop, the mRNA transcripts of CfC1qDC were detected in all the stages, and the expression level was up-regulated from D-hinged larva and reached the highest at eye-spot larva. The endogenous CfC1qDC was dominantly located in the hepatopancreas, gill, kidney and gonad of adult scallop through immunofluorescence. The recombinant protein of CfC1qDC (rCfC1qDC could not only bind various PAMPs, such as LPS, PGN, β-glucan as well as polyI:C, but also enhance the phagocytic activity of scallop hemocytes towards Escherichia coli. Meanwhile, rCfC1qDC could interact with human heat-aggregated IgG, and this interaction could be inhibited by LPS. CONCLUSIONS: All these results indicated that CfC1qDC in C. farreri not only served as a PRR involved in the PAMPs recognition, but also an opsonin participating in the clearance of invaders in innate immunity. Moreover, the ability of CfC1qDC to interact with immunoglobulins provided a clue to understand the evolution of classical pathway in complement system.

  4. Piwi1 is essential for gametogenesis in mollusk Chlamys farreri.

    Science.gov (United States)

    Ma, Xiaoshi; Ji, Aichang; Zhang, Zhifeng; Yang, Dandan; Liang, Shaoshuai; Wang, Yuhan; Qin, Zhenkui

    2017-01-01

    Piwi (P-element induced wimpy testis) is an important gene involved in stem cell maintenance and gametogenesis in vertebrates. However, in most invertebrates, especially mollusks, the function of Piwi during gametogenesis remains largely unclear. To further understand the function of Piwi during gametogenesis, full-length cDNA of Piwi1 from scallop Chlamys farreri (Cf-Piwi1) was characterized, which consisted of a 2,637 bp open reading frame encoding an 878-amino acid protein. Cf-Piwi1 mRNA was mainly localized in the spermatogonia, spermatocytes, oogonia, oocytes of early development and intra-gonadal somatic cells. Additionally, the knockdown of Cf-Piwi1 by injection of Cf-Piwi1-dsRNA (double-stranded RNA) into scallop adductor led to a loss of germ cells in C. farreri gonads. Apoptosis was observed mainly in spermatocytes and oocytes of early development, as well as in a small number of spermatogonia and oogonia. Our findings indicate that Cf-Piwi1 is essential for gametogenesis in the scallop C. farreri.

  5. Application of monoclonal antibody against granulocytes of scallop Chlamys farreri on granulocytes occurrence at different developmental stages and antigenic cross-reactivity of granulocytes in five other bivalve species.

    Science.gov (United States)

    Xing, Jing; Tang, Xiaoqian; Ni, Yongqing; Zhan, Wenbin

    2014-01-01

    A monoclonal antibody (MAb) 6H7 raised specifically against granulocytes of scallop (Chlamys farreri) was employed to observe granulocyte occurrence successively in blastulae, gastrulae, trochophore larvae, D-shape larvae, umbo-veliger larvae and creeping larvae of C. farreri by immunohistochemistry assay contrasted with H&E stain using semi-thin sections. Moreover, the reactivity of the MAb with granulocytes of C. farreri, Bay scallop Argopecten irradians, Japanese scallop Patinopecten yessoensis, Blue mussel Mytilus edulis, Pacific oyster Crassostrea gigas and Manila clam Ruditapes philippinarum, was detected by immunofluorescence assay (IFA) with differential interference contrast and fluorescent microscopy and flow cytometric immunofluorescence assay (FCIFA). The results showed that positive signals were first observed at D-shape larval stage, about 28 h post fertilization, after that, umbo-veliger larvae exhibited the positive cells with a diameter of 3-5 μm distributed in velum, digestive gland and esophagus. Then in creeping larvae, the number of positive cells increased with average diameter of 5-7 μm, and widely distributed in foot, digestive gland, gills and adductor muscles. No positive signal was found in blastulae, gastrulae and trochophore larvae. The results of IFA and FCIFA showed MAb 6H7 reacted to granulocytes of C. farreri, A. irradians, P. yessoensis and C. gigas, and the positive percentage reactivity were 53 ± 2.5%, 15 ± 2.5%, 12 ± 2.1% and 19 ± 2.1%, respectively, however, no cross-reaction was detected in hemocytes of R. philippinarum and M. edulis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Chromosomal localization and molecular marker development of the lipopolysaccharide and beta-1,3-glucan binding protein gene in the Zhikong scallop Chlamys farreri (Jones et Preston (Pectinoida, Pectinidae

    Directory of Open Access Journals (Sweden)

    Pin Huan

    2010-01-01

    Full Text Available Zhikong scallop Chlamys farreri (Jones et Preston is an economically important species in China. Understanding its immune system would be of great help in controlling diseases. In the present study, an important immunity-related gene, the Lipopolysaccharide and Beta-1,3-glucan Binding Protein (LGBP gene, was located on C. farreri chromosomes by mapping several lgbp-containing BAC clones through fluorescence in situ hybridization (FISH. Through the localization of various BAC clones, it was shown that only one locus of this gene existed in the genome of C. farreri, and that this was located on the long arm of a pair of homologous chromosomes. Molecular markers, consisting of eight single nucleotide polymorphism (SNPs markers and one insertion-deletion (indel, were developed from the LGBP gene. Indel marker testing in an F1 family revealed slightly distorted segregation (p = 0.0472. These markers can be used to map the LGBP gene to the linkage map and assign the linkage group to the corresponding chromosome. Segregation distortion of the indel marker indicated genes with deleterious alleles might exist in the surrounding region of the LGBP gene.

  7. Comparative transcriptomics reveals genes involved in metabolic and immune pathways in the digestive gland of scallop Chlamys farreri following cadmium exposure

    Science.gov (United States)

    Zhang, Hui; Zhai, Yuxiu; Yao, Lin; Jiang, Yanhua; Li, Fengling

    2017-05-01

    Chlamys farreri is an economically important mollusk that can accumulate excessive amounts of cadmium (Cd). Studying the molecular mechanism of Cd accumulation in bivalves is difficult because of the lack of genome background. Transcriptomic analysis based on high-throughput RNA sequencing has been shown to be an efficient and powerful method for the discovery of relevant genes in non-model and genome reference-free organisms. Here, we constructed two cDNA libraries (control and Cd exposure groups) from the digestive gland of C. farreri and compared the transcriptomic data between them. A total of 227 673 transcripts were assembled into 105 071 unigenes, most of which shared high similarity with sequences in the NCBI non-redundant protein database. For functional classification, 24 493 unigenes were assigned to Gene Ontology terms. Additionally, EuKaryotic Ortholog Groups and Kyoto Encyclopedia of Genes and Genomes analyses assigned 12 028 unigenes to 26 categories and 7 849 unigenes to five pathways, respectively. Comparative transcriptomics analysis identified 3 800 unigenes that were differentially expressed in the Cd-treated group compared with the control group. Among them, genes associated with heavy metal accumulation were screened, including metallothionein, divalent metal transporter, and metal tolerance protein. The functional genes and predicted pathways identified in our study will contribute to a better understanding of the metabolic and immune system in the digestive gland of C. farreri. In addition, the transcriptomic data will provide a comprehensive resource that may contribute to the understanding of molecular mechanisms that respond to marine pollutants in bivalves.

  8. A novel multi-domain C1qDC protein from Zhikong scallop Chlamys farreri provides new insights into the function of invertebrate C1qDC proteins.

    Science.gov (United States)

    Wang, Leilei; Wang, Lingling; Zhang, Daoxiang; Jiang, Qiufen; Sun, Rui; Wang, Hao; Zhang, Huan; Song, Linsheng

    2015-10-01

    The C1q domain containing (C1qDC) proteins are a family of proteins possessing globular C1q (gC1q) domains, and they rely on this domain to recognize various ligands such as PAMPs, immunoglobulins, ligands on apoptotic cell. In the present study, a novel multi-domain C1qDC protein (CfC1qDC-2) was identified from scallop Chlamys farreri, and its full length cDNA was composed of 1648 bp, encoding a signal peptide and three typical gC1q domains. BLAST analysis revealed significant sequence similarity between CfC1qDC-2 and C1qDC proteins from mollusks. Three gC1q domains were predicted in its tertiary structure to form a tightly packed bell-shaped trimer, and each one adopted a typical 10-stranded sandwich fold with a jelly-roll topology and contained six aromatic amino acids forming the hydrophobic core. The mRNA transcripts of CfC1qDC-2 were mainly detected in the tissues of hepatopancreas and gonad of adult scallops, and the expression level was up-regulated in hemocytes after stimulated by LPS, PGN and β-glucan. During the embryonic development of scallop, the mRNA transcripts of CfC1qDC-2 were presented in all the detected stages, and the expression level was up-regulated from D-hinged larvae and reached the highest at eye-spot larvae. The recombinant protein of MBP-CfC1qDC-2 (rCfC1qDC-2) could bind various PAMPs including LPS, PGN, LTA, β-glucan, mannan as well as polyI:C, and different microorganisms including three Gram-negative bacteria, three Gram-positive bacteria and two yeasts, as well as scallop apoptotic cells. Meanwhile, rCfC1qDC-2 could interact with human heat-aggregated IgG and IgM, and inhibit the C1q-dependent hemolysis of rabbit serum. All these results indicated that CfC1qDC-2 could recognize not only PAMPs as a PRR, but also the apoptotic cells. Moreover, the similar structures and functions shared by CfC1qDC-2 and complement C1q provided a new insight into the evolution of C1qDC proteins in complement system. Copyright © 2015 Elsevier Ltd

  9. Expression characteristics of Odf3 in gonad are different between Chlamys farreri and vertebrates

    Science.gov (United States)

    Ma, Xiaoshi; Liang, Shaoshuai; Yang, Dandan; Ji, Aichang; Ma, Xiaoru; Zhang, Zhifeng

    2017-02-01

    Outer dense fibers are specific subcellular components of mammal sperm flagella, apart from the axoneme and its associated proteins. As one of the outer dense fibers components, ODF3 is essential for the formation of mammal sperm flagella. In the present study, we isolated the Odf3 gene, 1033 bp in length, from Zhikong scallop Chlamys farreri, which was named as Cf-Odf3. It was predicted that Cf-Odf3 encodes a protein of 240 amino acids which contains 5 discontinuous Pro-Gly-Pro repeats. The Cf-Odf3 transcripts were detected in both testis and ovary of C. farreri at various stages through qRT-PCR. The Cf-ODF3 protein synthesized by prokaryotes was purified using Ni2+-NTA affinity chromatography and used to produce its polyclonal antibody. The antibody product was effective and specific as was examined by Western blotting. The Cf-Odf3 transcript and Cf-ODF3 protein were located in intragonadal somatic cells (ISCs), spermatogonia and spermatocytes of C. farreri testes, while no transcription of Cf-Odf3 and synthesis of Cf-ODF3 were detected in spermatids and spermatozoa. The location of Odf3 expression is different from that of vertebrates where ODF3 is synthesized specifically in spermatids and sperm flagella. Moreover, the Cf-Odf3 expression was also detected in ISCs, oogonia and oocytes of the scallop ovaries. Our finding revealed a different characteristic of Odf3 expression between scallop and vertebrates, which implied that Cf-Odf3 played a role in the gametogenesis of C. farreri.

  10. Biomarker responses in the bivalve Chlamys farreri to the water-soluble fraction of crude oil

    Science.gov (United States)

    Jiang, Fenghua; Zhang, Li; Yang, Baijuan; Zheng, Li; Sun, Chengjun

    2015-07-01

    To investigate the effect of the water soluble fraction of crude oil (WSF) on marine bivalves, the scallop Chlamys farreri was exposed to three WSF concentrations (0.18 mg/L, 0.32 mg/L, and 0.51 mg/L, respectively) in seawater. Petroleum hydrocarbon contents in scallops and a suite of enzymes [7-Ethoxyresorufin-O-deethylase (EROD), aryl hydrocarbon hydroxylase (AHH), glutathione S-transferase (GST), and glutathione peroxidase (GPx)] in gills and digestive glands were monitored over 10 days. The results revealed that WSF affected the activity of the four enzymes in the gills and digestive glands. EROD activity in the gills was significantly induced in most individuals of the three test groups, while in the digestive gland it was significantly induced in the low-concentration group within 4 days but was inhibited in the middle- and high-concentration groups on days 1, 4, and 10. AHH activity in the gills of all treatment groups was significantly induced on day 1. In the digestive gland, AHH activity was induced in most individuals from the treatment groups. In all treatment groups, GST activity was significantly inhibited from days 2 to 10 in the gills and was induced after day 4 in the digestive gland. GPx activity in the gills was significantly inhibited throughout the exposure period in all treatment groups. There was no overall significant difference in GPx activity in the digestive gland between the control and treatment groups. Our results also revealed that petroleum hydrocarbon concentrations in the tissues increased linearly with exposure time. EROD activity in the digestive gland and GST and GPx activity in the gill tissue were negatively correlated with petroleum hydrocarbon body burden. These enzymes play important roles in detoxification and can act as potential biomarkers for monitoring petroleum hydrocarbon contaminants in the marine environment.

  11. Molecular characterization of TGF-β type I receptor gene (Tgfbr1 in Chlamys farreri, and the association of allelic variants with growth traits.

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    Huihui Guo

    Full Text Available BACKGROUND: Scallops are an economically important aquaculture species in Asian countries, and growth-rate improvement is one of the main focuses of scallop breeding. Investigating the genetic regulation of scallop growth could benefit scallop breeding, as such research is currently limited. The transforming growth factor beta (TGF-β signaling through type I and type II receptors, plays critical roles in regulating cell proliferation and growth, and is thus a plausible candidate growth regulator in scallops. RESULTS: We cloned and characterized the TGF-β type I receptor (Tgfbr1 gene from Zhikong scallops (Chlamys farreri. The deduced amino acid sequence contains characteristic residues and exhibits the conserved structure of Tgfbr1 proteins. A high expression level of scallop Tgfbr1 was detected during early embryonic stages, whereas Tgfbr1 expression was enriched in the gonad and striated muscle in adults. A single nucleotide polymorphism (SNP, c. 1815C>T in the 3' UTR was identified. Scallops with genotype TT had higher growth traits values than those with genotype CC or CT in a full-sib family, and significant differences were found between genotypes CC and TT for shell length, shell height, and striated muscle weight. An expression analysis detected significantly more Tgfbr1 transcripts in the striated muscle of scallops with genotype CC compared to those with genotype TT or CT. Further evaluation in a population also revealed higher striated muscle weight in scallops with genotype TT than those with the other two genotypes. The inverse correlation between striated muscle mass and Tgfbr1 expression is consistent with TGF-β signaling having a negative effect on cell growth. CONCLUSION: The scallop Tgfbr1 gene was cloned and characterized, and an SNP potentially associated with both scallop growth and Tgfbr1 expression was identified. Our results suggest the negative regulation of Tgfbr1 in scallop growth and provide a candidate marker for

  12. Two novel LRR-only proteins in Chlamys farreri: Similar in structure, yet different in expression profile and pattern recognition.

    Science.gov (United States)

    Wang, Mengqiang; Wang, Lingling; Xin, Lusheng; Wang, Xiudan; Wang, Lin; Xu, Jianchao; Jia, Zhihao; Yue, Feng; Wang, Hao; Song, Linsheng

    2016-06-01

    Leucine-rich repeat (LRR)-only proteins could mediate protein-ligand and protein-protein interactions and be involved in the immune response. In the present study, two novel LRR-only proteins, CfLRRop-2 and CfLRRop-3, were identified and characterized from scallop Chlamys farreri. They both contained nine LRR motifs with the consensus signature sequence LxxLxLxxNxL and formed typical horseshoe structure. The CfLRRop-2 and CfLRRop-3 mRNA transcripts were constitutively expressed in haemocytes, muscle, mantle, gill, haepatopancreas and gonad, with the highest expression level in haepatopancreas and gill, respectively. During the ontogenesis of scallop, the mRNA transcripts of CfLRRop-2 were kept at a high level in oocytes and embryos, while those of CfLRRop-3 were expressed at a rather low level from oocytes to blastula. Their mRNA transcripts were significantly increased after the stimulation of lipopolysaccharide (LPS), peptidoglycan (PGN), glucan (GLU) and polyinosinic-polycytidylic acid (poly I:C), and the mRNA expression of CfLRRop-2 rose more intensely than that of CfLRRop-3. After the suppression of CfTLR (previously identified Toll-like receptor in C. farreri) via RNA interference (RNAi), CfLRRop-3 mRNA transcripts increased more intensely and lastingly than those of CfLRRop-2. The rCfLRRop-3 protein could bind LPS, PGN, GLU and poly I:C, while rCfLRRop-2 exhibited no significant binding activity to them. Additionally, rCfLRRop-2 could significantly induce the release of TNF-α from the mixed primary cultured scallop haemocytes, but rCfLRRop-3 failed. These results collectively indicated that CfLRRop-2 might act as an immune effector or pro-inflammatory factor, while CfLRRop-3 would function as a pattern recognition receptor (PRR), suggesting the function of LRR-only protein family has differentiated in scallop. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Scallop genome reveals molecular adaptations to semi-sessile life and neurotoxins

    National Research Council Canada - National Science Library

    Yuli Li; Xiaoqing Sun; Xiaoli Hu; Xiaogang Xun; Jinbo Zhang; Ximing Guo; Wenqian Jiao; Lingling Zhang; Weizhi Liu; Jing Wang; Ji Li; Yan Sun; Yan Miao; Xiaokang Zhang; Taoran Cheng; Guoliang Xu; Xiaoteng Fu; Yangfan Wang; Xinran Yu; Xiaoting Huang; Wei Lu; Jia Lv; Chuang Mu; Dawei Wang; Xu Li; Yu Xia; Yajuan Li; Zhihui Yang; Fengliang Wang; Lu Zhang; Qiang Xing; Huaiqian Dou; Xianhui Ning; Jinzhuang Dou; Yangping Li; Dexu Kong; Yaran Liu; Zhi Jiang; Ruiqiang Li; Shi Wang; Zhenmin Bao

    2017-01-01

    .... Here, we investigate the genome, various transcriptomes, and proteomes of the scallop Chlamys farreri, a semi-sessile bivalve with well-developed adductor muscle, sophisticated eyes, and remarkable...

  14. Response to selection for shell length in the noble scallop, Chlamys ...

    African Journals Online (AJOL)

    The noble scallop, Chlamys nobilis is one of the most economically important fishery and aquaculture species in the southern coast of China. In the present study, we conducted a one generation mass selection for shell length in a cultured noble scallop stock with a selection intensity of 1.732, to examine their response to ...

  15. The first CUB-domain containing serine protease from Chlamys farreri which might be involved in larval development and immune response.

    Science.gov (United States)

    Yang, Chuanyan; Wang, Leilei; Zhang, Huan; Yi, Qilin; Wang, Lingling; Wang, Hao; Song, Linsheng

    2017-11-01

    Serine proteases (SPs) are one of the most well understood enzyme families, which play an important role in regulating many physiological events. In the present study, one CUB-domain containing serine protease was identified from Chlamys farreri (designated as CfCUBSP). The full-length cDNA of CfCUBSP was of 3181 bp with an open reading frame of 2688 bp encoding a polypeptide of 896 amino acids. CfCUBSP shared closer phylogenetic relationship with those multi-domain SPs which consisted of one SP domain, and different numbers of CUB domain and LDLa domain than other SPs. The mRNA transcripts of CfCUBSP were detected in all developmental stages with the highest expression level in fertilized eggs and the lowest in trochophore larvae. In adult scallop, the CfCUBSP mRNA could be detected in all examined tissues with the highest level in hepatopancreas, and CfCUBSP protein was dominantly located in the gills, hepatopancreas, gonad and kidney. The mRNA expression of CfCUBSP in hemocytes was significantly up-regulated after the stimulation of lipopolysaccharide (LPS), peptidoglycan (PGN) and β-glucan (GLU) (P < 0.05). All the results collectively indicated that CfCUBSP was a primitive member of the invertebrate SPs which might be involved in larval development and immune response against Gram-negative (G-) and Gram-positive (G+) bacteria and fungus in scallop. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. A de novo transcriptome of the noble scallop, Chlamys nobilis, focusing on mining transcripts for carotenoid-based coloration

    OpenAIRE

    Liu, Helu; Zheng, Huaiping; Zhang, Hongkuan; Deng, Longhui; Liu, Wenhua; Wang, Shuqi; Meng, Fang; Wang, Yajun; Guo, Zhicheng; Li, Shengkang; Zhang, Guofan

    2015-01-01

    Background The noble scallop Chlamys nobilis Reeve displays polymorphism in shell and muscle colors. Previous research showed that the orange scallops with orange shell and muscle had a significantly higher carotenoid content than the brown ones with brown shell and white muscle. There is currently a need to identify candidate genes associated with carotenoid-based coloration. Results In the present study, 454 GS-FLX sequencing of noble scallop transcriptome yielded 1,181,060 clean sequence r...

  17. Is an Apicomplexan Parasite Responsible for the Collapse of the Iceland Scallop (Chlamys islandica) Stock?

    Science.gov (United States)

    Kristmundsson, Árni; Erlingsdóttir, Ásthildur; Freeman, Mark A

    2015-01-01

    Due to the total and unexpected collapse of the Iceland scallop, Chlamys islandica, stocks around Iceland during the 2000s, a commercial fishing ban has been imposed on this valuable resource since 2003. Following the initial identification of an apicomplexan parasite in the scallops, a long-term surveillance program was established to evaluate the effect of the parasite on the population. The infections were highly prevalent in all shell sizes throughout the study. However, the parasite only impacts mature scallops where they cause severe macroscopic changes, characterized by an extensively diminished and abnormally coloured adductor muscle. A highly significant relationship was observed between infection intensity and gonad and adductor muscle indices. The first four years of the study, were characterized by high infection intensity and very poor condition of the adductor muscle and gonads, whilst during subsequent years, infections gradually decreased and the condition of the scallops improved. Histopathological changes were restricted to the presence of apicomplexan zoites which were widely distributed, causing varying degrees of pathology in all organs. In heavy infections, muscular and connective tissues were totally necrotized, destroying significant parts of numerous organs, especially the adductor muscle, digestive gland and gonads. The progression of the disease was in good synchrony with the mortality rates and the subsequent decline observed in the scallop stock and recruitment indices. Our findings strongly suggest that the apicomplexan parasite played a major role in the collapse of the Iceland scallop stock in Breidafjordur. In addition to causing mortality, the infections significantly impact gonad development which contributes further to the collapse of the stock in the form of lower larval recruitment. Furthermore, compelling evidence exists that this apicomplexan pathogen is causing serious disease outbreaks in other scallop populations. Similar

  18. Biomarker modulation associated with marine diesel contamination in the Iceland scallop (Chlamys islandica).

    Science.gov (United States)

    Milinkovitch, Thomas; Geraudie, Perrine; Camus, Lionel; Huet, Valérie; Thomas-Guyon, Hélène

    2015-12-01

    The decrease of ice cover in the Arctic will lead to an increase of ship traffic in the upcoming decades. Consequently, oil pollution is expected. In this context, the goals of this study were to evaluate the biological impact of marine diesel contamination and, on this basis, to determine analytical tools of interest (biomarkers) for future biomonitoring of diesel spills. Using a 7-day contamination protocol, this study investigated biochemical modulations in the digestive gland of the Iceland scallop (Chlamys islandica). Incorporation of contaminants was verified assessing haemolymph metabolites. Results showed a response of glutathione-S-transferase to contamination suggesting detoxification processes and the suitability of such a tool for diesel spill biomonitoring. The lack of modulation of superoxide dismutase activity and lipid peroxidation suggests no oxidative stress and the unsuitability of these molecular tools for biomonitoring.

  19. BIOLOGICAL AND ECOLOGICAL CHARACTERISTICS OF VARIEGATED SCALLOP Chlamys varia (LINNAEUS, 1758.) – AS THE BASIS FOR FARMING

    OpenAIRE

    Nenad Antolović; Mara Antolović

    2012-01-01

    Pectinides are a highly regarded sea product among the consumers. Huge efforts are being made for the development of farming technology. All around the world the local species of the Pectinidae family are being consumed along with some newly introduced species as for example Japanese scallop (Patinopecten yessoensis Jay, 1858). Althougt there are 16 species of shellfish from eastern Adriatic that are offered in Croatian markets, only two species are being farmed. Chlamys varia (variegated sca...

  20. A de novo transcriptome of the noble scallop, Chlamys nobilis, focusing on mining transcripts for carotenoid-based coloration.

    Science.gov (United States)

    Liu, Helu; Zheng, Huaiping; Zhang, Hongkuan; Deng, Longhui; Liu, Wenhua; Wang, Shuqi; Meng, Fang; Wang, Yajun; Guo, Zhicheng; Li, Shengkang; Zhang, Guofan

    2015-02-05

    The noble scallop Chlamys nobilis Reeve displays polymorphism in shell and muscle colors. Previous research showed that the orange scallops with orange shell and muscle had a significantly higher carotenoid content than the brown ones with brown shell and white muscle. There is currently a need to identify candidate genes associated with carotenoid-based coloration. In the present study, 454 GS-FLX sequencing of noble scallop transcriptome yielded 1,181,060 clean sequence reads, which were assembled into 49,717 isotigs, leaving 110,158 reads as the singletons. Of the 159,875 unique sequences, 11.84% isotigs and 9.35% singletons were annotated. Moreover, 3,844 SSRs and over 120,000 high confidence variants (SNPs and INDELs) were identified. Especially, one class B scavenge receptor termed SRB-like-3 was discovered to express only in orange scallops and absent in brown ones, suggesting a significant association with high carotenoid content. Down-regulation of SRB-like-3 mRNA by RNA interference remarkably decreased blood carotenoid, providing compelling evidence that SRB-like-3 is an ideal candidate gene controlling carotenoid deposition and determining orange coloration. Transcriptome analysis of noble scallop reveals a novel scavenger receptor significantly associated with orange scallop rich in carotenoid content. Our findings pave the way for further functional elucidation of this gene and molecular basis of carotenoid deposition in orange scallop.

  1. BIOLOGICAL AND ECOLOGICAL CHARACTERISTICS OF VARIEGATED SCALLOP Chlamys varia (LINNAEUS, 1758. – AS THE BASIS FOR FARMING

    Directory of Open Access Journals (Sweden)

    Nenad Antolović

    2012-03-01

    Full Text Available Pectinides are a highly regarded sea product among the consumers. Huge efforts are being made for the development of farming technology. All around the world the local species of the Pectinidae family are being consumed along with some newly introduced species as for example Japanese scallop (Patinopecten yessoensis Jay, 1858. Althougt there are 16 species of shellfish from eastern Adriatic that are offered in Croatian markets, only two species are being farmed. Chlamys varia (variegated scallop is often found in many locations, most often where the s alredy egsist shellfish farming. Many authors believe that farming must be conducted in the hatcheries since the spat settlement on the collectors has proven unsuccessful and dependent of many environmental factors. The research of hatchery cultivation of this species has been described. In most areas where the reproductive cycle has been studied there appear to be two main periods of spawning each year, but the timing can differ between areas, and between years.

  2. The subcellular fate of cadmium and zinc in the scallop Chlamys nobilis during waterborne and dietary metal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Pan Ke [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)], E-mail: wwang@ust.hk

    2008-12-11

    Subcellular metal distribution has received increasing attention in aquatic toxicology studies, but the relationship between metal distribution and metal biokinetics remains largely unexplored. A series of short-term experiments on different concentrations of dissolved and dietary metals and on metal elimination were conducted to investigate the dynamics of subcellular distribution of Cd and Zn in the scallop Chlamys nobilis, a bivalve species that is known to accumulate very high concentrations of Cd and Zn in its tissues. Our results showed that, in general, both Cd and Zn were sequestered in insoluble forms (organelles, metal-rich granules, and cellular debris). The main binding pool for the newly acquired metals was organelles for Cd and cellular debris for Zn. Metallothionein-like protein (MTLP) was the most important storage pool for Cd in the scallops. Storage in the non-toxic form both in organelles and MTLP instead of through exocytosis was the major detoxification strategy to control Cd and accounted for the low efflux rate of Cd from scallops. In contrast to Cd, the main binding pool for Zn was cellular debris. Significant changes were found in the scallops when they were challenged with different concentrations of metals in the aqueous and food phases. Such changes provide important information on how scallops handle metals when there is increasing metal uptake. The redistribution of Zn among each subcellular compartment was much faster than the redistribution of Cd, suggesting an effective regulation mechanism for Zn in scallops. Thus, knowing subcellular metal distribution helps in studying the toxicity of both waterborne and dietborne metals.

  3. Sperm density required for inducing gynogenetic haploidy in scallop Chlamys nobilis

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.

    Experiments conducted for standardizing sperm density for artificial insemination and inducing gynogenesis by ultra-violet rays irradiated sperms in Chlamys nobilis showed that 10:1 ratio of sperms to eggs, gave maximum rate of fertilization...

  4. The genetic diversity of the noble scallop (Chlamys nobilis, Reeve 1852) in China assessed using five microsatellite markers.

    Science.gov (United States)

    Wang, Yanhong; Fu, Dingkun; Xia, Jianjun

    2013-03-01

    Five highly variable microsatellite loci were used to investigate the genetic diversity and population structure of the noble scallop Chlamys nobilis, in the South China Sea. A total of 200 individual scallops from 4 populations were genotyped. All of the 5 microsatellite loci screened in this study showed polymorphism. A total of 32 different alleles were observed over all loci. The number of alleles per locus ranged from 3 to 12. The average allelic number of these polymorphic markers was 6.4. The averages of observed (Ho) and expected heterozygosity (He) ranged from 0.07 to 0.32 and from 0.119 to 0.459, respectively. A highly significant deviation from the Hardy-Weinberg Law, owing primarily to heterozygote deficiency, was found in all populations studied. The Nanao population exhibited more genetic diversity than the other three populations in terms of allele richness and observed and expected heterozygosity. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Response to selection for shell length in the noble scallop, Chlamys ...

    African Journals Online (AJOL)

    AJL

    2012-05-03

    May 3, 2012 ... rising consumption of scallop products and the decline of natural resource have led to increasing aquaculture practices and stock transfer of this species (Ma and Yu,. 2009). At present, genetic improvement of cultured populations to obtain new strains suitable for culture. (example strains with higher growth ...

  6. Seasonal variation in biomarkers in blue mussel (Mytilus edulis), Icelandic scallop (Chlamys islandica) and Atlantic cod (Gadus morhua)-Implications for environmental monitoring in the Barents Sea

    Energy Technology Data Exchange (ETDEWEB)

    Nahrgang, J., E-mail: jasmine.m.nahrgang@uit.no [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Brooks, S.J. [Norwegian Institute for Water Research (NIVA), NO-0349 Oslo (Norway); Evenset, A. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Camus, L. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); University Centre In Svalbard (UNIS), NO-9171 Longyearbyen (Norway); Jonsson, M.; Smith, T.J. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Lukina, J. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); University of Tromso, Faculty of Biosciences, Fisheries and Economics, Department of Arctic and Marine Biosciences, NO-9037 Tromso (Norway); Frantzen, M. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Giarratano, E. [Centro Nacional Patagonico (CENPAT-CONICET), AR-9120 Puerto Madryn (Argentina); Renaud, P.E. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); University Centre In Svalbard (UNIS), NO-9171 Longyearbyen (Norway)

    2013-02-15

    In the Barents Sea, the limited data on biological relevant indicators and their responses to various anthropogenic stressors have hindered the development of a consistent scientific basis for selecting indicator species and developing practical procedures for environmental monitoring. Accordingly, the main aim of the present study was to develop a common set of baseline values for contaminants and biomarkers in three species, and to identify their strengths and limitations in monitoring of the Barents Sea. Blue mussel (Mytilus edulis), Icelandic scallop (Chlamys islandica) and Atlantic cod (Gadus morhua) were sampled from a north Norwegian fjord in March, June, September and December 2010. Digestive glands from the bivalve species and liver from Atlantic cod were analysed for biomarkers of oxidative stress (catalase [CAT], glutathione peroxidase [GPX], glutathione-S-transferase activities [GST], lipid peroxidation as thiobarbituric reactive substances [TBARS] and total oxyradical scavenging capacity [TOSC]), biotransformation (ethoxyresorufine-O-deethylase activity [EROD]) and general stress (lysosomal membrane stability [LMS]). Concentrations of polycyclic aromatic hydrocarbons (PAHs) and metals in the bivalves and PAH metabolites in fish bile were quantified. Finally, energy reserves (total lipids, proteins and carbohydrates) and electron transport system (ETS) activity in the digestive gland of the bivalves and liver of Atlantic cod provided background information for reproductive cycle and general physiological status of the organisms. Blue mussel and Icelandic scallop showed very similar trends in biological cycle, biomarker expression and seasonality. Biomarker baselines in Atlantic cod showed weaker seasonal variability. However, important biological events may have been undetected due to the large time intervals between sampling occasions. Physiological biomarkers such as energy reserves and ETS activity were recommended as complementary parameters to the

  7. Sea Scallop Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Sea Scallop Survey began in 1980 and has covered an area from Cape Hatteras to Georges Bank. The survey aims to determine the distribution and...

  8. Distribution and spatial trends of PCBs in commercial scallops from Galician littoral (NW, Spain). Possible influence of biometric parameters.

    Science.gov (United States)

    Carro, N; García, I; Ignacio, M; Mouteira, A

    2012-04-01

    Levels and profiles of 10 individual congeners of polychlorinated biphenyls (PCBs) were studied in 3 species of commercial scallops (Pecten maximus, Chlamys varia, and Chlamys opercularis) from several Rías in Galician littoral (NW, Spain). ΣPCBs levels ranged from 2.21 to 41.0 ng/g wet weight for P. maximus, from 13.9 to 24.9 ng/g wet weight for C. varia, and from 1.58 to 24.3 ng/g wet weight for C. opercularis. The possible influence between biometric parameters (lipid content, condition index, and shell size) and PCBs levels were studied using statistical analysis (ANOVA). No relationship between biometric parameters could be established in the studied samples. Multivariate analysis showed there were differences in bioaccumulation of some PCBs congeners. Principal component analysis classifies clearly the 3 studied Rías (Ría de Ferrol, Ría de Arousa, and Ría de Vigo) taking into account PCBs levels found in the shellfish. We investigated levels and profiles of 10 congeners of PCBs in 3 commercial scallop species from the Galician littoral zone. The influence of 3 biometric parameters on polychlorinated biphenyls (PCBs) levels was also studied in order to assess results from the monitoring programs of production areas. According to PCBs levels, geographical differences were observed in commercial scallops from the 3 studied estuarine bays (Ría de Ferrol, Ría de Arousa, and Ría de Vigo). © 2012 Institute of Food Technologists®

  9. Scallop License Limitation Program (SLLP) Permit Program

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A federal Scallop License Limitation Program (SLLP) license is required onboard any vessel deployed in scallop fisheries in Federal waters off Alaska (except for...

  10. Scalloping at the lumbosacral canal

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, R.

    1987-07-01

    Scalloping is an indentation of the dorsal side of the vertebral body (anterior wall of the lumbosacral or sacral canal) which typically involves several adjacent lumbal vertebral body segments and the anterior wall of the canalis sacralis. Occurrence without underlying disease is rare; it occurs most frequently with chondrodystrophy, neurofibromatosis, Morquio's syndrome, Hurler's syndrome, acromegaly, Ehlers-Danlos syndrome, Marfan's syndrome, cysts, tumors and in peridural lipomas.

  11. king scallop (Pecten maxinus) meats

    African Journals Online (AJOL)

    Post-rigor king scallop meats (Pecten maximus) were frozen individually for 24 h at -80°C and kept vacuum packed at -22°C for up to 301 days. Sampling was carried out on fresh meats and at days 1, 28, 91, 154, 210 and 301 of frozen storage. Tests related to muscle integrity ( -hydroxy-acyl-coenzyme –A dehydrogenase ...

  12. Index of /data/kazusa_chlamy_est_index/20111219 [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available Index of /data/kazusa_chlamy_est_index/20111219 Name Last modified Size Description Parent Directory - Chla...my_tfa.tar.gz 15-Sep-2009 13:44 7.7M README.html 06-Sep-2012 16:47 8.8K kazusa_chlam...y_est.zip 15-Sep-2009 13:42 4.9M Index of /data/kazusa_chlamy_est_index/20111219 ...

  13. Bay Scallop Spawning, Survival, Growth Records

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bay Scallops are selected and cultured according to criteria of growth and survival. Morphological attributes have also been selected to assess heretibility....

  14. Stock status update of Browns Bank North Scallops (Placopecten magellanicus)

    National Research Council Canada - National Science Library

    Keith, David; Broome, Jeremy; Reeves, Alan; Drew, Tricia Pearo; Themelis, Daphne; Stone, Heath; Bennett, Lottie; Docherty, Verna

    2017-01-01

    .... The purpose of this report is to update the status of Browns Bank North Scallop with data from the 2016 Scallop survey and fishery to provide science advice for the management of the 2017 fishery...

  15. Yorkie and Scalloped: partners in growth activation.

    Science.gov (United States)

    Bandura, Jennifer L; Edgar, Bruce A

    2008-03-01

    The Hippo (Hpo) signaling pathway limits organ growth in organisms from Drosophila to mammals by suppressing the activity of the transcriptional coactivator Yorkie (Yki)/YAP. The TEAD/TEF factor Scalloped (Sd) has been identified as the first known transcription factor to partner with Yki as a downstream target of Hpo signaling.

  16. Scalloped electrodes for highly sensitive electrical measurements

    DEFF Research Database (Denmark)

    Vazquez Rodriguez, Patricia; Dimaki, Maria; Svendsen, Winnie Edith

    2011-01-01

    In this work we introduce a novel out-of-plane electrode with pronounced scalloped surface and high aspect ratio for electrical recordings of brain tissue in vitro, with the aim to reduce significantly the impedance of the measuring system. The profile and height of the structures is tailored by ...

  17. Distribution and movement of scalloped hammerhead Sphryna ...

    African Journals Online (AJOL)

    Knowledge of population distribution and movement is crucial for the conservation and management of shark species occurring in coastal waters. From 1984 to 2009, 641 scalloped hammerheads Sphyrna lewini, 1 342 smooth hammerheads Sphyrna zygaena and 1 352 unspecified hammerheads Sphyrna spp. were ...

  18. Development of an in situ loop-mediated isothermal amplification technique for chromosomal localization of DNA sequences

    Science.gov (United States)

    Meng, Qinglei; Wang, Shi; Zhang, Lingling; Huang, Xiaoting; Bao, Zhenmin

    2013-01-01

    In situ loop-mediated isothermal amplification (in situ LAMP) combines in situ hybridization and loop-mediated isothermal amplification (LAMP) techniques for chromosomal localization of DNA sequences. In situ LAMP is a method that is generally more specific and sensitive than conventional techniques such as fluorescence in situ hybridization (FISH), primed in situ labeling (PRINS), and cycling primed in situ labeling (C-PRINS). Here, we describe the development and application of in situ LAMP to identify the chromosomal localization of DNA sequences. To benchmark this technique, we successfully applied this technique to localize the major ribosomal RNA gene on the chromosomes of the Zhikong scallop ( Chlamys farreri).

  19. The complete chloroplast genome sequence of Gentiana lawrencei var. farreri (Gentianaceae and comparative analysis with its congeneric species

    Directory of Open Access Journals (Sweden)

    Peng-Cheng Fu

    2016-09-01

    Full Text Available Background The chloroplast (cp genome is useful in plant systematics, genetic diversity analysis, molecular identification and divergence dating. The genus Gentiana contains 362 species, but there are only two valuable complete cp genomes. The purpose of this study is to report the characterization of complete cp genome of G. lawrencei var. farreri, which is endemic to the Qinghai-Tibetan Plateau (QTP. Methods Using high throughput sequencing technology, we got the complete nucleotide sequence of the G. lawrencei var. farreri cp genome. The comparison analysis including genome difference and gene divergence was performed with its congeneric species G. straminea. The simple sequence repeats (SSRs and phylogenetics were studied as well. Results The cp genome of G. lawrencei var. farreri is a circular molecule of 138,750 bp, containing a pair of 24,653 bp inverted repeats which are separated by small and large single-copy regions of 11,365 and 78,082 bp, respectively. The cp genome contains 130 known genes, including 85 protein coding genes (PCGs, eight ribosomal RNA genes and 37 tRNA genes. Comparative analyses indicated that G. lawrencei var. farreri is 10,241 bp shorter than its congeneric species G. straminea. Four large gaps were detected that are responsible for 85% of the total sequence loss. Further detailed analyses revealed that 10 PCGs were included in the four gaps that encode nine NADH dehydrogenase subunits. The cp gene content, order and orientation are similar to those of its congeneric species, but with some variation among the PCGs. Three genes, ndhB, ndhF and clpP, have high nonsynonymous to synonymous values. There are 34 SSRs in the G. lawrencei var. farreri cp genome, of which 25 are mononucleotide repeats: no dinucleotide repeats were detected. Comparison with the G. straminea cp genome indicated that five SSRs have length polymorphisms and 23 SSRs are species-specific. The phylogenetic analysis of 48 PCGs from 12 Gentianales

  20. The biochemical, textural and sensory properties of king scallop ...

    African Journals Online (AJOL)

    Triangle sensory comparisons between fresh and frozen scallop muscles suggested that characteristic freezing times up to 555 min may not influence the sensory quality of frozen scallop meats. Freezing of meats at the short freezing time of 19 min reduced freezing and thawing weight losses compared to longer time tested ...

  1. 50 CFR 648.59 - Sea Scallop Access Areas.

    Science.gov (United States)

    2010-10-01

    ...,447 mt), after accounting for applicable set-asides and LAGC IFQ TAC. (ii) LAGC IFQ scallop vessels—(A... section. LAGC IFQ vessels will be allocated 285,423 lb (129 mt) in fishing year 2010, which is 5 percent... the Federal Register, unless transiting pursuant to paragraph (f) of this section. (C) Scallops landed...

  2. Growth and survival of the South African scallop Pecten ...

    African Journals Online (AJOL)

    Grow-out studies of the scallop Pecten sulcicostatus, endemic to the South African coast, contribute to an investigation of the suitability of this species for commercial culture. Hatchery-reared juvenile scallops were placed in a suspended culture system at 5 m depth in Saldanha Bay on the west coast of South Africa.

  3. A Vestigial:Scalloped TEA domain chimera rescues the wing phenotype of a scalloped mutation in Drosophila melanogaster.

    Science.gov (United States)

    Srivastava, Ajay; MacKay, Julie O; Bell, John B

    2002-05-01

    The development of the Drosophila wing requires both scalloped and vestigial functions. Using a fusion between full-length Vestigial and the Scalloped TEA domain, the fusion protein can rescue scalloped wing mutations because within wing development, Scalloped and Vestigial cooperatively act as a transcription complex. Scalloped provides the necessary DNA binding function via the TEA domain and Vestigial promotes the activation of target genes. We also demonstrate that the putative nuclear localization signal contained in the TEA domain of Scalloped is likely responsible for the nuclear localization of Vestigial. The fusion protein is also capable of activating a known target gene of the native complex and thus represents a tool that will be helpful in rapidly identifying target genes of the Sd/Vg complex that are involved in wing differentiation. The functionality of the fusion suggests that only the TEA domain of Scalloped is critical for wing development and the rest of the protein (about 70%) is dispensable. This result is novel and should stimulate further studies of sd in other tissues in view of the fact that scalloped is a vital gene in Drosophila. Copyright 2002 Wiley-Liss, Inc.

  4. Preoperative scallop-by-scallop assessment of mitral prolapse using 2D-transthoracic echocardiography

    Directory of Open Access Journals (Sweden)

    Leonetti Stefania

    2010-01-01

    Full Text Available Abstract Background This study was conducted to assess the accuracy of harmonic imaging 2D-transthoracic echocardiography (2D-TTE segmental analysis compared to surgical findings, in degenerative mitral regurgitation (MR. Methods Seventy-seven consecutive patients with severe degenerative MR were prospectively enrolled. Preoperative 2D-TTE with precise localization of prolapsing or flailing scallops/segments was performed. All patients underwent mitral valve surgical repair. Surgical reports (SR, including valve description, were used as references for comparisons. A postoperative control 2D-TTE was performed. Results Out of 462 scallops/segments studied, surgical inspection identified 102 prolapses or flails (22%, 92 of which had previously been detected by 2D-TTE (90.2% sensitivity, 100% specificity. Agreement between preoperative 2D-TTE segmental analysis and SR was 97.8% (k = 0.93; p Conclusions 2D-TTE, performed by an experienced echo-lab, has very good diagnostic accuracy in localizing the scallops/segments involved in degenerative MR, particularly for the middle ones (P2-A2, which represent almost the totality of prolapses. More invasive, time consuming and expensive exams should be reserved to selected cases.

  5. Diet of scalloped hammerhead shark in eastern Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Juvenile scalloped hammerhead sharks, Sphyrna lewini, were collected in northwest Florida to examine foraging ecology, bioenergetics, and trophic level (30-60 cm FL...

  6. Impact of seawater carbonate variables on post-larval bivalve calcification

    Science.gov (United States)

    Li, Jiaqi; Mao, Yuze; Jiang, Zengjie; Zhang, Jihong; Bian, Dapeng; Fang, Jianguang

    2017-05-01

    Several studies have demonstrated that shellfish calcification rate has been impacted by ocean acidification. However, the carbonate system variables responsible for regulating calcification rate are controversial. To distinguish the key variables, we manipulated a seawater carbonate system by regulating seawater pH and dissolved inorganic carbon (DIC). Calcification rates of juvenile blue mussel (Mytilus edulis) and Zhikong scallop (Chlamys farreri) were measured in different carbonate systems. Our results demonstrated that neither [HCO{3/-}], DIC, or pH ([H+]) were determining factors for the shellfish calcification rate of blue mussel or Zhikong scallop. However, a significant correlation was detected between calcification rate and DIC/[H+] and [CO{3/2-}] in both species.

  7. The biochemical, textural and sensory properties of king scallop ...

    African Journals Online (AJOL)

    USER

    2010-07-12

    Jul 12, 2010 ... cellular water formed by melting of the inter-cellular ice in the inter-cellular spaces was free to escape from the inter-cellular spaces before it could be reabsorbed by the fibres. Scallop meats frozen at a 'fast' characteristic freezing time (tc) of 19 min would have intra-cellular ice crystals. These ice crystals ...

  8. A genetic linkage map of Japanese scallop Mizuhopecten ...

    African Journals Online (AJOL)

    A genetic linkage map of the Japanese scallop Mizuhopecten yessoensis was constructed based on 302 markers, including 263 amplified fragment length polymorphism (AFLP) markers and 39 microsatellite (SSR) markers. The two parental maps were constructed according to the double pseudo-test cross strategy with an ...

  9. Assessment of vertebral scalloping in neurofibromatosis type 1 with plain radiography and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Tsirikos, A.I.; Ramachandran, M.; Lee, J.; Saifuddin, A. E-mail: asaifuddin@aol.com

    2004-11-01

    AIM: To evaluate vertebral scalloping in patients with neurofibromatosis type 1 (NF-1) and spinal deformity using plain radiographs and magnetic resonance imaging (MRI), and to determine the possible aetiological association with neurofibromas, dural ectasia and lateral meningocoeles. MATERIAL AND METHODS: Nineteen patients with NF-1, who had full spine radiographs and whole-spine MRI, were retrospectively reviewed. Dystrophic features and their relationship to the curve were recorded from radiographs. A comparison was then made between the dystrophic features evident on radiographs and adjacent soft-tissue abnormalities identified on MRI. RESULTS: Dystrophic changes were documented in 16 patients on plain radiographs and in all patients on MRI. Rib pencilling was the most common finding on radiographs. In 80% of the cases with scoliosis, scalloping was seen on the concavity of the curvature. In all patients with kyphoscoliosis, scalloping was contiguous to the apex of kyphosis. Twenty-four areas of scalloping were identified on MRI. Scalloping usually developed in the concavity of the scoliotic curve or at levels unrelated to the curve. Scalloping was evident in combination with dural ectasia or neurofibroma in 15 cases. The presence of dural ectasia was confirmed in 75% of the cases of posterior scalloping and in 25% of those of lateral scalloping. The presence of neurofibromas was recognized in 25% of the cases of anterior or lateral scalloping. Dural ectasia was identified in two patients without associated scalloping. Lateral meningocoeles were not related to the development of scalloping. CONCLUSION: Whereas posterior scalloping was commonly associated with dural ectasia, anterior and lateral scalloping were commonly the result of primary mesodermal dysplasia.

  10. Differentiation between the traces of predation of muricids and naticids in Spanish Pliocene Chlamys

    Directory of Open Access Journals (Sweden)

    Reyment, R. A.

    1988-08-01

    Full Text Available The statistical analysis of holes drilled in species of the bivalve genus Chlamys from localities in the Lower Pliocene of Southern Spain throws light on aspects of muricid and naticid predation. Discriminant function analysis was found to be a useful means of identifying the nature of boreholes, with but slight errors of identification for known specimens. In particular, significant differences in relationships between predators and prey could be established. The question as to whether preferred locations of boreholes occur could be answered affirmatively for muricids. Also for muricids, the majority of the observed boreholes (74.1% are concentrated to the region fo the adductor muscle: such a relationship could not be definitely proven for naticids (36.9% within the adduetor muscle field. An association between the site of the prey and predator could only be demonstrated for naticids in connexion with prey of several species and genera. There is a strong association between the size of the prey and the site chosen for drilling for both groups of predators. There is indecisive evidence for a correlation between the location and size a drillhole for naticids, but probably not for muricids. The strategy of seleetion of a drilling site by muricids seems to• be to weaken the function of the adductor muscle in the monomyarian Chlamys, hence facilitating access to the víscera. In general, multivariate analytical procedures, and especiaIly the method of canonical correlations, were found lo aid greatly the interpretation of the quantitative observations.El análisis estadístico de los orificios perforados en las especies del género Chlamys del Plioceno Inferior del Sur de España aclara algunos aspectos muy interesantes sobre la predacción de los murícidos y natícidos. El análisis de la función discriminante se ha determinado como un método muy útil para identificar la naturaleza de los orificios, son muy pocos los errores de

  11. Production of Chitosan from Amusium sp Scallop Shell Waste

    Science.gov (United States)

    Rokhati, Nur; Istirokhatun, Titik; Titik Apriyanti, Dwi; Susanto, Heru

    2017-02-01

    Chitosan is one of the natural polysaccharides, which is produced from chitin by deacetylation process. In this study, chitosan was produced from Amusium sp scallop shell waste. First, chitin was isolated by extraction via deproteinization using alkaline solution followed by demineralization using acid solution. Thereafter, chitosan was resulted from deacetylation of chitin using a high concentration of alkaline solution. The chemical structure of chitin and chitosan products was characterized using fourier transform infrared spectroscopy (FTIR).

  12. INFLUENZA DELLE CONDIZIONI ECOLOGICHE SULLA STRATEGIA RIPRODUTTIVA E SULLA BIOMETRIA DI CHLAMYS OPERCULARIS (L. 1758) (MOLLUSCA, BIVALVIA)

    OpenAIRE

    NEGUSANTI, JIN SOOK

    2007-01-01

    2005/2006 Chlamys opercularis è un animale edule, comune su fondi sabbiosi e sabbiosi-detritici, posti ad una profondità variabile tra 4-400m (più comune a 40m). Ha una conchiglia di colore molto vario, inequivalve (valva sinistra più convessa) ed inequilaterale, con una lunghezza massima di 9cm. La scultura conchigliare è caratterizzata da 18-25 coste radiali, presenti su ciascuna valva, tra le quali si trovano le linee di accrescimento. L'interno è lucido, solcato ed ondulato in corrispo...

  13. 50 CFR 648.60 - Sea scallop area access program requirements.

    Science.gov (United States)

    2010-10-01

    ... Management Measures for the Atlantic Sea Scallop Fishery § 648.60 Sea scallop area access program....83(a)(1), and the additional restrictions for Atlantic cod, haddock, and yellowtail flounder... (d)(4). (A) Atlantic cod. Such vessel may bring onboard and possess only up to 100 lb (45.4 kg) of...

  14. 76 FR 40674 - Fisheries of the Exclusive Economic Zone Off Alaska; Scallops

    Science.gov (United States)

    2011-07-11

    ... prevent overfishing in the target fishery for weathervane scallops. Implementing these measures would... estimate of spawning biomass for weathervane scallops, the overfishing level (OFL) is specified as the MSY...-Stevens Act relative to preventing overfishing and establishing an ABC and ACL. The following is a summary...

  15. 76 FR 23794 - Stock Status Determination for Atlantic Highly Migratory Scalloped Hammerhead Shark

    Science.gov (United States)

    2011-04-28

    ... Scalloped Hammerhead Shark AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... an Atlantic highly migratory species (HMS) scalloped hammerhead shark, and the stock is overfished... sharks in U.S. waters. Based on this paper, in 2005, the population was estimated to be at 45 percent of...

  16. Meat Composition and Quality Assessment of King Scallops (Pecten maximus and Frozen Atlantic Sea Scallops (Placopecten magellanicus on a Retail Level

    Directory of Open Access Journals (Sweden)

    Monika Manthey-Karl

    2015-09-01

    Full Text Available An enlarged range of scallop products on the market allows the consumer to buy lower priced alternatives, which often raises the question of quality and control. Frozen meat of king scallops (Pecten maximus and Atlantic sea scallops (Placopecten magellanicus were purchased on the German market and compared with fresh shell-on king scallops of various origin. The approximate composition, inclusive citric acid and phosphates, minerals, free amino acids (FAA and fatty acid profiles were examined in the muscle to identify changes as a result of processing. The FAA glycine and taurine as well the fatty acids 20:5n-3 (EPA and 22:6n-3 (DHA were the most abundant, but were reduced in processed samples. Di- and triphosphate contents were not detectable (<0.01 g·kg−1 in untreated meats. Most frozen scallop products contained added citrates and polyphosphates and had distinctly higher water contents (up to 89% and an increased moisture to protein ratio (M/P (up to 9 compared with the fresh king scallops (78%, M/P < 5. Labelling of species, verified by PCR-based DNA analysis, and ingredients were not correct in each case. Overall results indicated no relevant differences in mineral content, except high sodium contents, resulting from additives. Labelling does not readily allow the consumer to recognize the extent of processing effects.

  17. Paradoxical scalloped placenta with polyhydramnios in twin-twin transfusion syndrome.

    Science.gov (United States)

    Chmait, Ramen H; Rossi, A Cristina; Quintero, Rubén A

    2007-01-01

    To describe the paradoxical occurrence of a scalloped placenta in the presence of polyhydramnios and assess its clinical significance in pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated with laser therapy. All patients who underwent laser therapy for TTTS between January 2003 and April 2004 were studied. TTTS was diagnosed and staged using the Quintero staging system. Normally the placenta is characterized by undulations of the fetal-placental surface visible by ultrasound (scalloped placenta). Patients with polyhydramnios will typically have a flattened, smooth, non-scalloped placenta. Operative tapes were reviewed and placental type assigned. Pre-, intra-, and postoperative characteristics of each study patient were obtained. Fifteen of 120 patients (12.5%) were noted to have a scalloped placenta despite having polyhydramnios. There was no difference in mean gestational age at laser treatment (20.3+/-0.5 vs. 19.6+/-0.6 weeks, p=0.66) or in stage (p=0.07) between the two groups. The median and range preoperative maximum vertical pocket (MVP) in the recipient gestational sac differed significantly between the scalloped and non-scalloped patients (8.3 (8-12) vs. 10.5 (8-17), p=0.001). All 15 patients (100%) with a scalloped placenta required an amnioinfusion to expose all vascular anastomoses, while amnioinfusion was necessary in only 28 of the 105 patients (26.7%, por=8 cm in the recipient sac. Most patients will have a flattened placenta as a result of polyhydramnios in this sac. Our data show that a paradoxical scalloped placenta may still be present in approximately 12.5% of patients. This preoperative sonographic finding alerts to the potential need for amnioinfusion during laser therapy for TTTS to disclose all vessels to avoid missing placental vascular anastomoses. Amniocenteses should be avoided if possible in patients considering laser therapy to minimize the likelihood of iatrogenic placental scalloping.

  18. Antibacterial characteristics of heated scallop-shell nano-particles.

    Science.gov (United States)

    Watanabe, Takashi; Fujimoto, Riku; Sawai, Jun; Kikuchi, Mikio; Yahata, Shinya; Satoh, Susumu

    2014-01-01

    Heated scallop-shell (HSS) nano-particles, prepared using a wet grinding mill, and microparticles were examined for their antibacterial activity against vegetative bacterial cells and spores. The median diameters of the nano-particles and micro-particles were approximately 20 nm and 30 µm, respectively. The antibacterial activity of HSS against Escherichia coli increased with an increase in concentration, regardless of particle size; however, the antibacterial activity of the nano-particles was much higher than that of micro-particles. The sporicidal activity of the nano-particles was also much higher than that of micro-particles, with HSS nano-particles able to kill Bacillus subtilis spores. A reduction of more than three orders of magnitude for B. subtilis spores was confirmed following a 30 min treatment at 5 mg/ml and 60℃, showing that the combination of HSS nano-particle treatment with mild heating was particularly effective for controlling bacterial spores.

  19. Habitat characteristics predicting distribution and abundance patterns of scallops in D'Entrecasteaux Channel, Tasmania.

    Science.gov (United States)

    Mendo, Tania; Lyle, Jeremy M; Moltschaniwskyj, Natalie A; Tracey, Sean R; Semmens, Jayson M

    2014-01-01

    Habitat characteristics greatly influence the patterns of distribution and abundance in scallops, providing structure for the settlement of spat and influencing predation risk and rates of survival. Establishing scallop-habitat relationships is relevant to understanding the ecological processes that regulate scallop populations and to managing critical habitats. This information is particularly relevant for the D'Entrecasteaux Channel, south-eastern Tasmania (147.335 W, 43.220 S), a region that has supported significant but highly variable scallop production over many years, including protracted periods of stock collapse. Three species of scallops are present in the region; the commercial scallop Pecten fumatus, the queen scallop Equichlamys bifrons, and the doughboy scallop Mimachlamys asperrima. We used dive surveys and Generalized Additive Modelling to examine the relationship between the distribution and abundance patterns of each species and associated habitat characteristics. The aggregated distribution of each species could be predicted as a function of sediment type and species-specific habitat structural components. While P. fumatus was strongly associated with finer sediments and E. bifrons with coarse grain sediments, M. asperrima had a less selective association, possibly related to its ability to attach on a wide range of substrates. Other habitat characteristics explaining P. fumatus abundance were depth, Asterias amurensis abundance, shell and macroalgae cover. Equichlamys bifrons was strongly associated with macroalgae and seagrass cover, whereas M. asperrima abundance was greatly explained by sponge cover. The models define a set of relationships from which plausible hypotheses can be developed. We propose that these relationships are mediated by predation pressure as well as the specific behavioural characteristics of each species. The findings also highlight the specific habitat characteristics that are relevant for spatial management and habitat

  20. Habitat characteristics predicting distribution and abundance patterns of scallops in D'Entrecasteaux Channel, Tasmania.

    Directory of Open Access Journals (Sweden)

    Tania Mendo

    Full Text Available Habitat characteristics greatly influence the patterns of distribution and abundance in scallops, providing structure for the settlement of spat and influencing predation risk and rates of survival. Establishing scallop-habitat relationships is relevant to understanding the ecological processes that regulate scallop populations and to managing critical habitats. This information is particularly relevant for the D'Entrecasteaux Channel, south-eastern Tasmania (147.335 W, 43.220 S, a region that has supported significant but highly variable scallop production over many years, including protracted periods of stock collapse. Three species of scallops are present in the region; the commercial scallop Pecten fumatus, the queen scallop Equichlamys bifrons, and the doughboy scallop Mimachlamys asperrima. We used dive surveys and Generalized Additive Modelling to examine the relationship between the distribution and abundance patterns of each species and associated habitat characteristics. The aggregated distribution of each species could be predicted as a function of sediment type and species-specific habitat structural components. While P. fumatus was strongly associated with finer sediments and E. bifrons with coarse grain sediments, M. asperrima had a less selective association, possibly related to its ability to attach on a wide range of substrates. Other habitat characteristics explaining P. fumatus abundance were depth, Asterias amurensis abundance, shell and macroalgae cover. Equichlamys bifrons was strongly associated with macroalgae and seagrass cover, whereas M. asperrima abundance was greatly explained by sponge cover. The models define a set of relationships from which plausible hypotheses can be developed. We propose that these relationships are mediated by predation pressure as well as the specific behavioural characteristics of each species. The findings also highlight the specific habitat characteristics that are relevant for spatial

  1. Electroreception in juvenile scalloped hammerhead and sandbar sharks.

    Science.gov (United States)

    Kajiura, Stephen M; Holland, Kim N

    2002-12-01

    The unique head morphology of sphyrnid sharks might have evolved to enhance electrosensory capabilities. The 'enhanced electroreception' hypothesis was tested by comparing the behavioral responses of similarly sized carcharhinid and sphyrnid sharks to prey-simulating electric stimuli. Juvenile scalloped hammerhead sharks Sphyrna lewini and sandbar sharks Carcharhinus plumbeus oriented to dipole electric fields from the same maximum distance (approximately 30 cm) and thus demonstrated comparable behavioral-response thresholds (hammerheads typically demonstrated a pivot orientation in which the edge of the cephalofoil closest to the dipole remained stationary while the shark bent its trunk to orient to the center of the dipole. By contrast, sandbars swam in a broader arc towards the center of the dipole. The different orientation patterns are attributed to the hydrodynamic properties of the cephalofoil, which enables the hammerheads to execute sharp turns at high speed. The greater trunk width of the sandbar sharks prevented them from demonstrating the same degree of flexibility. Therefore, although the sphyrnid head morphology does not appear to confer a greater sensitivity to prey-simulating dipole electric fields, it does provide (1). a greater lateral search area, which may increase the probability of prey encounter, and (2). enhanced maneuverability, which may aid in prey capture.

  2. Global phylogeography of the scalloped hammerhead shark (Sphyrna lewini).

    Science.gov (United States)

    Duncan, K M; Martin, A P; Bowen, B W; DE Couet, H G

    2006-07-01

    Large marine fishes typically have little population genetic structure. The exceptions are associated with sedentary behaviour, disjunct distributions, or reproductive philopatry. Scalloped hammerhead sharks (Sphyrna lewini) incorporate the contrasting traits of oceanic habitat (usually associated with high dispersal) and possible fidelity to nursery grounds (for reproductive females). To evaluate the expectations of these contrasting behaviours, we examined the global genetic structure of S. lewini based on collections (n = 271 individuals) from 20 nursery areas. A 548-bp fragment of mitochondrial DNA control region revealed 22 polymorphic sites, 24 haplotypes, and three lineages distinguished by 2.56-3.77% sequence divergence. Coalescence analyses based on a provisional molecular clock indicate an origin in the Indo-West Pacific with late Pleistocene radiations into the central Pacific (Hawaii) and eastern Pacific (Central America), as well as recent interchange between oceans via southern Africa. Population subdivisions are strong (overall Phi(ST) = 0.749, P 10). We conclude that nursery populations linked by continuous coastline have high connectivity, but that oceanic dispersal by females is rare. Although we cannot rule out philopatry to natal nurseries, oceanic barriers appear to have a much stronger influence on the genetic architecture of this species and may indicate a mechanism for recent evolutionary radiations in the genus Sphyrna.

  3. Kinematics and critical swimming speed of juvenile scalloped hammerhead sharks

    Science.gov (United States)

    Lowe

    1996-01-01

    Kinematics and critical swimming speed (Ucrit) of juvenile scalloped hammerhead sharks Sphyrna lewini were measured in a Brett-type flume (635 l). Kinematic parameters were also measured in sharks swimming in a large pond for comparison with those of sharks swimming in the flume. Sharks in the flume exhibited a mean Ucrit of 65±11 cm s-1 (± s.d.) or 1.17±0.21 body lengths per second (L s-1), which are similar to values for other species of sharks. In both the flume and pond, tailbeat frequency (TBF) and stride length (LS) increased linearly with increases in relative swimming speed (Urel=body lengths traveled per second). In the flume, tailbeat amplitude (TBA) decreased with increasing speed whereas TBA did not change with speed in the pond. Differences in TBF and LS between sharks swimming in the flume and the pond decreased with increases in Urel. Sharks swimming at slow speeds (e.g. 0.55 L s-1) in the pond had LS 19 % longer and TBF 21 % lower than sharks in the flume at the same Urel. This implies that sharks in the flume expended more energy while swimming at comparable velocities. Comparative measurements of swimming kinematics from sharks in the pond can be used to correct for effects of the flume on shark swimming kinematics and energetics.

  4. Insular dentin formation pattern in human odontogenesis in relation to the scalloped dentino-enamel junction.

    Science.gov (United States)

    Radlanski, Ralf J; Renz, Herbert

    2007-01-01

    This study is a first report on the modality of early dentin formation in respect to the scalloped pattern of the dentino-enamel junction (DEJ). We applied scanning electron microscopy (SEM), transmission electron microscopy (TEM), histological serial sections, and three-dimensional (3D) reconstructions. TEM and SEM showed scallops and secondary scallops on the DEJ of deciduous dental primordia and on deciduous teeth with the enamel cap removed. This peculiar outline of the DEJ requires a specific dentin formation pattern; histological sections showed that dentin formation began at the brims of the scallops, seen as triangular spikes in serial sections. The dentin formation front was not uniform; instead, it was characterized by multiple, insular forming centers, as revealed by our 3D reconstructions. As thicker dentin layers formed, the islands became confluent. Factors are discussed, which may lead to crimpling of the inner enamel epithelium, and maintained as the scalloped pattern of the DEJ develops. Signaling patterns in accordance with the insular dentin formation are unknown so far.

  5. Genomic characterization of interspecific hybrids between the scallops Argopecten purpuratus and A. irradians irradians.

    Directory of Open Access Journals (Sweden)

    Liping Hu

    Full Text Available The Peruvian scallop (Argopecten purpuratus has been introduced to China and has successfully been hybridized with the bay scallop (A. irradians irradians. The F1 hybrids of these two scallops exhibited a large increase in production traits and some other interesting new characteristics. To understand the genetic basis of this heterosis, nuclear gene and partial mtDNA sequences, and genomic in situ hybridization (GISH were employed to analyze the genomic organization of the hybrids. Amplification of the ribosomal DNA internal transcribed spacer (ITS showed that the parental ITS sequences were present in all the hybrid individuals, illustrating that the hybrid offspring inherited nuclear DNA from both parents. Sequence analyses of the ITS region further confirmed that the hybrids harbored alleles from their parents; some recombinant variants were also detected, which revealed some alterations in the nuclear genetic material of the hybrids. The analysis of mitochondrial 16S rDNA showed that the hybrids possessed sequences that were identical to the 16S rDNA of the female parents, proving a matrilineal inheritance of mitochondrial genes in scallops. In addition, GISH clearly discriminated between the parental chromosomes and indicated a combination of haploid genomes of duplex parents in the hybrids. The genetic analyses in our study illustrated that the F1 hybrids inherited nuclear material from both parents and cytoplasmic genetic material maternally, and some variations occurred in the genome, which might contribute to a further understanding of crossbreeding and heterosis in scallop species.

  6. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic). BAY SCALLOP,

    Science.gov (United States)

    1983-10-01

    bottom was probably Maritime waters. Robert (1978) caused by heavy siltation of holding recommended that if scallops were cages at that depth; many...1961. Studies on the grass. Ecology 28: 321-322. bay scallop in Alligator Harbour , Florida. Ph.D. Thesis. Florida Marshall, N. 1960. Studies of the

  7. Effect of ultrasound pretreatment on hot air drying rate of scallop muscles

    Science.gov (United States)

    Bai, Yaxiang; Fan, Xuejie; Bi, Yujing

    2017-05-01

    To improve the drying rate and to reduce the energy consumption of aquatic product, scallop muscles were treated by ultrasonic with different frequency, time and different temperature. The hot air drying rate of treated scallop muscles was determined, and, meanwhile, several quality parameters such as the shrinkage and rehydration rate of samples with pretreatment were determined to compare with those of untreated samples. The results indicated that the drying rate of scallop muscles can be improved by the ultrasonic pretreatment without affecting the quality. Under a 70 kHz for 30min at 25°C, the drying rate of pretreatments is 1.29 times higher compared with that of the control group.

  8. 78 FR 73499 - Proposed Information Collection; Comment Request; Atlantic Sea Scallops Amendment 10 Data Collection

    Science.gov (United States)

    2013-12-06

    ... Sea Scallops Amendment 10 Data Collection AGENCY: National Oceanic and Atmospheric Administration... regulations implementing the FMP are at 50 CFR Part 648. To successfully implement and administer components...; broken trip adjustment and access area trip exchange, 10 minutes; VMS purchase and installation, 2 hours...

  9. 75 FR 36559 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery; Framework Adjustment 21

    Science.gov (United States)

    2010-06-28

    ... full-time vessel had an unused 9,000-lb (4,082-kg) NLAA compensation trip (half of the full possession...: Total allowable catch (TAC); open area days-at-sea (DAS) and Sea Scallop Access Area (access area) trip... F target (0.24), in addition to the revised DAS model, would better achieve OY while also being...

  10. 77 FR 52 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery; Framework Adjustment 23

    Science.gov (United States)

    2012-01-03

    ... scallop gear as well. Overall, data suggest that sea turtles are most likely to be present in areas that... cutting bar and the top of the dredge frame must be less than or equal to 45 degrees. (3) All bale bars... reduce the likelihood of a sea turtle passing under the dredge frame when the gear is on the seafloor...

  11. 76 FR 43773 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery; Framework Adjustment 22

    Science.gov (United States)

    2011-07-21

    ... calculate each vessel's IFQ for a given FY. For the LA fleet, Amendment 15 set a management uncertainty... Framework Adjustment 22 (Framework 22) to the Atlantic Sea Scallop Fishery Management Plan (FMP), which was developed and adopted by the New England Fishery Management Council (Council). The specifications in...

  12. Variability in multiple paternity rates for grey reef sharks (Carcharhinus amblyrhynchos) and scalloped hammerheads (Sphyrna lewini).

    Science.gov (United States)

    Green, M E; Appleyard, S A; White, W; Tracey, S; Ovenden, J

    2017-05-08

    This study assessed the presence and prevalence of multiple paternity (MP) in litters of grey reef sharks (Carcharhinus amblyrhynchos) and scalloped hammerheads (Sphyrna lewini) opportunistically caught in Papua New Guinea (PNG). Litter size between species were significantly different with an average of 3.3 pups for grey reef sharks and 17.2 pups for scalloped hammerhead. Using 14 and 10 microsatellite loci respectively, we identified MP in 66% of grey reef sharks (4 out of 6 litters) and 100% MP in scalloped hammerheads (5 litters). We found high paternal skew (the uneven contribution of sires per litter) and a positive correlation between female adult size and litter size in scalloped hammerheads but not in grey reef sharks. Differences in the frequency of MP between species and the identification of paternal skew may be linked with mating strategies and post-copulatory mechanisms. Multiple paternity is thought to benefit populations by enhancing genetic diversity therefore increasing the population's genetic resilience to extrinsic pressures. The identification of MP in two shark species reported here, further elucidates the complex breeding strategies elasmobranchs undertake.

  13. 76 FR 61996 - Fishery Management Plan for the Scallop Fishery Off Alaska; Amendment 13

    Science.gov (United States)

    2011-10-06

    ...) and accountability measures (AMs) to prevent overfishing in the target fishery for weathervane... absence of a statewide estimate of spawning biomass for weathervane scallops, the overfishing level (OFL... the Magnuson-Stevens Act relative to preventing overfishing and establishing an ABC and ACL. The...

  14. Hydrolysates from scallop and squid processing byproducts as specialty aquafeed ingredients

    Science.gov (United States)

    Around 9,000 MT of squid (Loligo pealei) is landed annually in Rhode Island, USA, most of which is processed resulting in 40-50% unutilized byproducts (about 3,500 MT). On the other hand, the sea scallop (Placopecten magellanicus) resource off New England is currently at historic high levels of 22,7...

  15. Multiple field-based methods to assess the potential impacts of seismic surveys on scallops.

    Science.gov (United States)

    Przeslawski, Rachel; Huang, Zhi; Anderson, Jade; Carroll, Andrew G; Edmunds, Matthew; Hurt, Lynton; Williams, Stefan

    2017-10-30

    Marine seismic surveys are an important tool to map geology beneath the seafloor and manage petroleum resources, but they are also a source of underwater noise pollution. A mass mortality of scallops in the Bass Strait, Australia occurred a few months after a marine seismic survey in 2010, and fishing groups were concerned about the potential relationship between the two events. The current study used three field-based methods to investigate the potential impact of marine seismic surveys on scallops in the region: 1) dredging and 2) deployment of Autonomous Underwater Vehicles (AUVs) were undertaken to examine the potential response of two species of scallops (Pecten fumatus, Mimachlamys asperrima) before, two months after, and ten months after a 2015 marine seismic survey; and 3) MODIS satellite data revealed patterns of sea surface temperatures from 2006-2016. Results from the dredging and AUV components show no evidence of scallop mortality attributable to the seismic survey, although sub-lethal effects cannot be excluded. The remote sensing revealed a pronounced thermal spike in the eastern Bass Strait between February and May 2010, overlapping the scallop beds that suffered extensive mortality and coinciding almost exactly with dates of operation for the 2010 seismic survey. The acquisition of in situ data coupled with consideration of commercial seismic arrays meant that results were ecologically realistic, while the paired field-based components (dredging, AUV imagery) provided a failsafe against challenges associated with working wholly in the field. This study expands our knowledge of the potential environmental impacts of marine seismic survey and will inform future applications for marine seismic surveys, as well as the assessment of such applications by regulatory authorities. Copyright © 2017. Published by Elsevier Ltd.

  16. Effect of helical angle on path scallop calculation of flat-end cutter in multi axis milling

    Science.gov (United States)

    Hendriko, Hendriko

    2017-10-01

    This paper presents an analytical method to calculate path scallop height of flat-end cutter during free-form surface machining. In this study the effect of helical angle of cutting edge was taken into consideration in the calculation. The scallop height was determined from the coordinate of the path intersection point. Path intersection point is an intersection between the cutting tool of the current tooth path and the previous tooth path. One model part with free-form surface was tested to verify the applicability of the proposed method. The scallop height obtained using the tool with helical angle and the one without helical angle were compared. The result showed that the helical angle tend to decrease the scallop height. The verification test to check the accuracy of the proposed method was performed. The result proved that the method was accurate.

  17. De novo assembly and characterization of two transcriptomes reveal multiple light-mediated functions in the scallop eye (Bivalvia: Pectinidae)

    National Research Council Canada - National Science Library

    Pairett, Autum N; Serb, Jeanne M

    2013-01-01

    ... of this group, which is due, in part, to a lack of genomic resources. The scallop (Bivalvia: Pectinidae) represents a compeling molluscan model to study photoreception due to its morphologically novel and separately evolved mirror-type eye...

  18. Hooking mortality of scalloped hammerhead Sphyrna lewini and great hammerhead Sphyrna mokarran sharks caught on bottom longlines

    National Research Council Canada - National Science Library

    Gulak, SJB; de Ron Santiago, AJ; Carlson, JK

    2015-01-01

    The scalloped hammerhead Sphyrna lewini and the great hammerhead S. mokarran are typically caught as bycatch in a variety of fisheries and are listed as globally Endangered by the International Union for the Conservation of Nature...

  19. Methods comparison for microsatellite marker development: Different isolation methods, different yield efficiency

    Science.gov (United States)

    Zhan, Aibin; Bao, Zhenmin; Hu, Xiaoli; Lu, Wei; Hu, Jingjie

    2009-06-01

    Microsatellite markers have become one kind of the most important molecular tools used in various researches. A large number of microsatellite markers are required for the whole genome survey in the fields of molecular ecology, quantitative genetics and genomics. Therefore, it is extremely necessary to select several versatile, low-cost, efficient and time- and labor-saving methods to develop a large panel of microsatellite markers. In this study, we used Zhikong scallop ( Chlamys farreri) as the target species to compare the efficiency of the five methods derived from three strategies for microsatellite marker development. The results showed that the strategy of constructing small insert genomic DNA library resulted in poor efficiency, while the microsatellite-enriched strategy highly improved the isolation efficiency. Although the mining public database strategy is time- and cost-saving, it is difficult to obtain a large number of microsatellite markers, mainly due to the limited sequence data of non-model species deposited in public databases. Based on the results in this study, we recommend two methods, microsatellite-enriched library construction method and FIASCO-colony hybridization method, for large-scale microsatellite marker development. Both methods were derived from the microsatellite-enriched strategy. The experimental results obtained from Zhikong scallop also provide the reference for microsatellite marker development in other species with large genomes.

  20. Data on color and chemical composition of dried scallop (Mizuhopecten yessoensis produced in different areas of Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    Hisaki Enda

    2018-02-01

    Full Text Available Dried scallop is used in Chinese, Japanese, and French cuisines for its unique flavor and taste. The quality of dried scallop is rated according to its clear, shiny brown color, developed by the Maillard reaction between sugars and amino acids. This article reports the colors, represented by L* and a* values, and chemical composition (water, salinity, Brix, proteins, and amino acids of dried scallop products. The dried scallops were produced in Tokoro, Sarufutsu, and Saroma in Hokkaido, Japan. The color of the dried scallops had values of 45.7–52.0 for L* and 2.31–5.08 for a*. The salinity of the products was 15.1–17.7%. The amino acid contents were 1350.8–1668.6 mg/100 g. The data collected here are provided in table format. The data can serve as a reference for commercial dried scallop products to determine product quality.

  1. Development of method to remove weld scallop and ceramic backing material of wedge type and its application

    Science.gov (United States)

    Kang, Sung-Koo; Yang, Jong-Soo; Kim, Ho-Kyung

    2015-06-01

    The weld scallop has been used for joining T-bars. There are a lot of weld scallops in shipbuilding. It is difficult to perform scallop welding due to the inconvenient welding position. This results in many problems such as porosity, slag inclusion, etc. In this study, a new method is devised to remove weld scallops by incorporating a Ceramic Backing Material (CBM). The weld scallop is removed by an elongation of the v groove. In order to insert a CBM into the groove without a weld scallop, a wedge-shaped CBM is developed. The top side of the developed CBM is similar to the shape of a general back bead. The bottom surface has a saw-toothed shape for cutting at a suitable length. This can be attached to the root side of a face plate using adhesive tape, just like a general CBM. Welding experiments in normal and abnormal conditions are carried out and the possibility of burn-through is examined. This CBM's applicability to shipbuilding is verified.

  2. Development of method to remove weld scallop and ceramic backing material of wedge type and its application

    Directory of Open Access Journals (Sweden)

    Sung-Koo Kang

    2015-03-01

    Full Text Available The weld scallop has been used for joining T-bars. There are a lot of weld scallops in shipbuilding. It is difficult to perform scallop welding due to the inconvenient welding position. This results in many problems such as porosity, slag inclusion, etc. In this study, a new method is devised to remove weld scallops by incorporating a Ceramic Backing Material (CBM. The weld scallop is removed by an elongation of the v groove. In order to insert a CBM into the groove without a weld scallop, a wedge-shaped CBM is developed. The top side of the developed CBM is similar to the shape of a general back bead. The bottom surface has a saw-toothed shape for cutting at a suitable length. This can be attached to the root side of a face plate using adhesive tape, just like a general CBM. Welding experiments in normal and abnormal conditions are carried out and the possibility of burn-through is examined. This CBM’s applicability to shipbuilding is verified.

  3. Formation and Evolution of Scalloped Depressions on Malea Planum and the southern rim of the Hellas Basin, Mars

    Science.gov (United States)

    Zanetti, M.; Hiesinger, H.; Reiss, D.; Neukum, G.

    2008-09-01

    Introduction: Scalloped depressions are an erosional surface morphology characterized as a type of dissected mantle terrain by Milliken and Mustard [1]. They are identified by their asymmetrical north-south profile which shows a steep pole-facing scarp, a flat floor, and a gentle equator-facing slope which grades into the surrounding terrain [1]. They are found in latitudedependent, ice-rich surface mantles in both the northern and southern hemispheres [1]. The mantle material is presumably composed of atmospherically derived dust and water ice, and is thought to be related to obliquity-driven ice activity as recently as 2.1-0.4 Myr ago [3]. Previous researchers, [e.g. 1,2,4-7] have attributed the formation of scallops to the sublimation of interstitial ice. Morgenstern et al. [6] suggested that the asymmetric profile of scallops can be explained by enhanced solar insolation on the equator-facing slope which leads to enhanced sublimation of interstial ice and thereby increases the area of the depression. By this process they can also grow and coalesce to form large degraded areas [6]. Building on our previous work [7], we investigate this hypothesis using HiRISE and THEMIS-IR images. We also propose a hypothesis for the nucleation and evolution of scallops. Previous Work: Our previous work surveyed the southern hemisphere using HRSC images for the presence of scalloped terrain, and revealed that almost all scalloped terrains are in the Malea Planum region near the southern wall of the Hellas basin [7]. We mapped the distribution of scalloped terrain between 50° and 70° E and 50° and 70° S. The results of the map showed that the scalloped terrains contour the southern wall of the Hellas basin between the elevations of 1000 m and -2000 m, and that the icerich mantle is thickest in this region [7]. Data and Methods: High resolution HiRISE images of the scalloped terrain of Malea Planum were used to investigate small scale features. Daytime infrared images from

  4. Scallop-Inspired DNA Nanomachine: A Ratiometric Nanothermometer for Intracellular Temperature Sensing.

    Science.gov (United States)

    Xie, Nuli; Huang, Jin; Yang, Xiaohai; He, Xiaoxiao; Liu, Jianbo; Huang, Jiaqi; Fang, Hongmei; Wang, Kemin

    2017-11-21

    Accurate measurement of intracellular temperature is of great significance in biology and medicine. With use of DNA nanotechnology and inspiration by nature's examples of "protective and reversible responses" exoskeletons, a scallop-inspired DNA nanomachine (SDN) is desgined as a ratiometric nanothermometer for intracellular temperature sensing. The SDN is composed of a rigid DNA tetrahedron, where a thermal-sensitive molecular beacon (MB) is embedded in one edge of the DNA tetrahedron. Relying on the thermal-sensitive MB and fluorescence resonance energy transfer (FRET) signaling mechanism, the "On" to "Off" signal is reversibly responding to "below" and "over" the melting temperature. Mimicking the functional anatomy of a scallop, the SDN exhibits high cellular permeability and resistance to enzymatic degradation, good reversibility, and tunable response range. Furthermore, FRET ratiometric signal that allows the simultaneous recording of two emission intensities at different wavelengths can provide a feasible approach for precise detection, minimizing the effect of system fluctuations.

  5. Processing Sliding Mosaic Mode Data with Modified Full-Aperture Imaging Algorithm Integrating Scalloping Correction

    Directory of Open Access Journals (Sweden)

    Zhao Tuan

    2016-10-01

    Full Text Available In this study, we present a modified full-aperture imaging algorithm that includes scalloping correction and spike suppression for sliding-Mosaic-mode Synthetic Aperture Radar (SAR. It is innovational to correct the azimuth beam-pattern weighting altered by radar antenna rotation in the azimuth during the deramping preprocessing operation. The main idea of spike suppression is to substitute zeros between bursts with linear-predicted data extrapolated from adjacent bursts to suppress spikes caused by multiburst processing. We also integrate scalloping correction for the sliding mode into this algorithm. Finally, experiments are performed using the C-band airborne SAR system with a maximum bandwidth of 200 MHz to validate the effectiveness of this approach.

  6. Reproductive biology of the scalloped Hammerhead shark Sphyrna lewini (Chondrichthyes: Sphyrnidae) off southwest Mexico

    OpenAIRE

    Bejarano-Álvarez, Marcela; Galván Magaña, Felipe; Ochoa Báez, Rosa Isabel

    2011-01-01

    The scalloped hammerhead shark Sphyrna lewini is the most important species in the artisanal shark fishery in the Gulf of Tehuantepec, Mexico. The knowledge about their reproductive biology in the area is nonexistent, despite their being listed worldwide as endangered by the IUCN. To determine the basic biology of reproduction in this shark would give important data to establish management or conservation plans for this species in Mexico. Samples were collected of 991 hammerhead sharks (342 f...

  7. Molecular and functional analysis of scalloped recessive lethal alleles in Drosophila melanogaster.

    OpenAIRE

    Srivastava, Ajay; Simmonds, Andrew J.; Garg, Ankush; Fossheim, Leif; Campbell, Shelagh D.; Bell, John B.

    2004-01-01

    The Drosophila melanogaster scalloped (sd) gene is a homolog of the human TEF-1 gene and is a member of the TEA/ATTS domain-containing family of transcription factors. In Drosophila, sd is involved in wing development as well as neural development. Herein, data are presented from a molecular analysis of five recessive lethal sd alleles. Only one of these alleles complements a viable allele associated with an sd mutant wing phenotype, suggesting that functions important for wing development ar...

  8. Isolation and characterization of melanin pigment from yesso scallop Patinopecten yessoensis

    Science.gov (United States)

    Sun, Xiujun; Wu, Biao; Zhou, Liqing; Liu, Zhihong; Dong, Yinghui; Yang, Aiguo

    2017-04-01

    Melanin is one of the essential compounds in the pigments of molluscan shells. However, the effects of melanin on color variations in molluscs are largely unknown. Our previous study suggests that Yesso scallop Patinopecten yessoensis might contain melanin pigment in the dark brown shell. We therefore isolated melanin from the pigmented shells using hydrochloric acid method, and characterized the types of melanin pigments by spectrophotometry. The purified melanin, which was verified by spectrophotometry scanning and HPLC analysis, showed the typical characteristics of melanin absorption spectra and HPLC chromatograms. The contents of pheomelanin and eumelanin in pigmented shells, which were determined by the linear standard curve of melanin at 405 nm and 350 nm absorbance, were 48.23 ± 1.350 and 157.65 ± 5.905 mg, respectively. The present results indicate that the brown-pigmented shells of scallops comprise approximately 76.6% of eumelanin and 23.4% of pheomelanin, which supports the presence of eumelanin-rich pigment in scallop shells. Therefore, the combination of hydrochloric acid extraction and spectrophotometric quantification is a rapid and efficient method to isolate and quantify melanin in shells. This will facilitate the melanin studies related to shell color polymorphism and the selective breeding of bivalves with different shell colors.

  9. De novo assembly and characterization of two transcriptomes reveal multiple light-mediated functions in the scallop eye (Bivalvia: Pectinidae.

    Directory of Open Access Journals (Sweden)

    Autum N Pairett

    Full Text Available BACKGROUND: The eye has evolved across 13 separate lineages of molluscs. Yet, there have been very few studies examining the molecular machinary underlying eye function of this group, which is due, in part, to a lack of genomic resources. The scallop (Bivalvia: Pectinidae represents a compeling molluscan model to study photoreception due to its morphologically novel and separately evolved mirror-type eye. We sequenced the adult eye transcriptome of two scallop species to: 1 identify the phototransduction pathway components; 2 identify any additional light detection functions; and 3 test the hypothesis that molluscs possess genes not found in other animal lineages. RESULTS: A total of 3,039 contigs from the bay scallop, Argopecten irradians and 26,395 contigs from the sea scallop, Placopecten magellanicus were produced by 454 sequencing. Targeted BLAST searches and functional annotation using Gene Ontology (GO terms and KEGG pathways identified transcripts from three light detection systems: two phototransduction pathways and the circadian clock, a previously unrecognized function of the scallop eye. By comparing the scallop transcriptomes to molluscan and non-molluscan genomes, we discovered that a large proportion of the transcripts (7,776 sequences may be specific to the scallop lineage. Nearly one-third of these contain transmembrane protein domains, suggesting these unannotated transcripts may be sensory receptors. CONCLUSIONS: Our data provide the most comprehensive transcriptomic resource currently available from a single molluscan eye type. Candidate genes potentially involved in sensory reception were identified, and are worthy of further investigation. This resource, combined with recent phylogenetic and genomic data, provides a strong foundation for future investigations of the function and evolution of molluscan photosensory systems in this morphologically and taxonomically diverse phylum.

  10. Biomineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification

    KAUST Repository

    Ramajo, Laura

    2015-12-08

    Future ocean acidification (OA) will affect physiological traits of marine species, with calcifying species being particularly vulnerable. As OA entails high energy demands, particularly during the rapid juvenile growth phase, food supply may play a key role in the response of marine organisms to OA. We experimentally evaluated the role of food supply in modulating physiological responses and biomineralization processes in juveniles of the Chilean scallop, Argopecten purpuratus, that were exposed to control (pH ~ 8.0) and low pH (pH ~ 7.6) conditions using three food supply treatments (high, intermediate, and low). We found that pH and food levels had additive effects on the physiological response of the juvenile scallops. Metabolic rates, shell growth, net calcification, and ingestion rates increased significantly at low pH conditions, independent of food. These physiological responses increased significantly in organisms exposed to intermediate and high levels of food supply. Hence, food supply seems to play a major role modulating organismal response by providing the energetic means to bolster the physiological response of OA stress. On the contrary, the relative expression of chitin synthase, a functional molecule for biomineralization, increased significantly in scallops exposed to low food supply and low pH, which resulted in a thicker periostracum enriched with chitin polysaccharides. Under reduced food and low pH conditions, the adaptive organismal response was to trade-off growth for the expression of biomineralization molecules and altering of the organic composition of shell periostracum, suggesting that the future performance of these calcifiers will depend on the trajectories of both OA and food supply. Thus, incorporating a suite of traits and multiple stressors in future studies of the adaptive organismal response may provide key insights on OA impacts on marine calcifiers.

  11. Purification and Identification of Antioxidant Peptides from Protein Hydrolysate of Scalloped Hammerhead (Sphyrna lewini Cartilage

    Directory of Open Access Journals (Sweden)

    Xue-Rong Li

    2017-03-01

    Full Text Available The aim of this study was to purify and identify peptides with antioxidant properties from protein hydrolysate of scalloped hammerhead (Sphyrna lewini cartilage. Cartilaginous proteins of the scalloped hammerhead were extracted by guanidine hydrochloride, and three antioxidant peptides, named enzymolysis peptide of scalloped hammerhead cartilage A (SCPE-A, SCPE-B and SCPE-C, were subsequently isolated from the hydrolysate of the cartilaginous proteins using ultrafiltration and chromatography. The amino acid sequences of SCPE-A, SCPE-B and SCPE-C were identified as Gly-Pro-Glu (GPE, Gly-Ala-Arg-Gly-Pro-Gln (GARGPQ, and Gly-Phe-Thr-Gly-Pro-Pro-Gly-Phe-Asn-Gly (GFTGPPGFNG, with molecular weights of 301.30 Da, 584.64 Da and 950.03 Da, respectively. As per in vitro activity testing, SCPE-A, SCPE-B and SCPE-C exhibited strong scavenging activities on 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH• (half elimination ratio (EC50 2.43, 2.66 and 1.99 mg/mL, hydroxyl radicals (HO• (EC50 0.28, 0.21 and 0.15 mg/mL, 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radicals (ABTS+• (EC50 0.24, 0.18 and 0.29 mg/mL, and superoxide anion radicals ( O 2 − • (EC50 0.10, 0.14 and 0.11 mg/mL. In addition, SCPE-A showed inhibition activity similar to butylated hydroxytoluene (BHT in lipid peroxidation in a linoleic acid model system. The amino acid residues of Gly, Pro and Phe could positively influence the antioxidant activities of GPE, GARGPQ and GFTGPPGFNG. These results suggested that GPE, GARGPQ and GFTGPPGFNG might serve as potential antioxidants and be used as food additives and functional foods.

  12. Effects of fouling on the Japanese scallop Mizuhopecten yessoensis (Jay) in Peter the Great Bay (Sea of Japan)

    Science.gov (United States)

    Gabaev, D. D.

    2013-03-01

    A valuable mariculture object, the Japanese scallop Mizuhopecten (= Patinopevten) yessoensis (Jay), after six hours long transportation by air and sowing on the bottom is fouled greater by epi- and endolythical organisms than the members of the native population. It is likely that the fouling negatively affects the specimens, those that were the largest before the sowing at the bottom were not found among those that reached puberty. The results of the effects of the endolythic polychaete Polydora brevipalpa and the barnacle Hesperibalanus hesperius on the growth rate of the Japanese scallop cultivated on the bottom of Peter the Great Bay (Sea of Japan) are provided in this paper.

  13. Scallop protein with endogenous high taurine and glycine content prevents high-fat, high-sucrose-induced obesity and improves plasma lipid profile in male C57BL/6J mice

    DEFF Research Database (Denmark)

    Tastesen, Hanne Sørup; Keenan, Alison H.; Madsen, Lise

    2014-01-01

    -sucrose diets with protein sources of increasing endogenous taurine content, i.e., chicken, cod, crab and scallop, for 6 weeks. The energy intake was lower in crab and scallop-fed mice than in chicken and cod-fed mice, but only scallop-fed mice gained less body and fat mass. Liver mass was reduced in scallop......-fed mice, but otherwise no changes in lean body mass were observed between the groups. Feed efficiency and apparent nitrogen digestibility were reduced in scallop-fed mice suggesting alterations in energy utilization and metabolism. Overnight fasted plasma triacylglyceride, non-esterified fatty acids...

  14. Conservation Genetics of the Scalloped Hammerhead Shark in the Pacific Coast of Colombia.

    Science.gov (United States)

    Quintanilla, Sonia; Gómez, Alberto; Mariño-Ramírez, Camila; Sorzano, Carolina; Bessudo, Sandra; Soler, German; Bernal, Jaime E; Caballero, Susana

    2015-01-01

    Previous investigations of the population genetics of the scalloped hammerhead sharks (Sphyrna lewini) in the Eastern Tropical Pacific have lacked information about nursery areas. Such areas are key to promoting conservation initiatives that can protect young sharks from threats such as overfishing. Here, we investigated the genetic diversity, phylogeography, and connectivity of S. lewini found in 3 areas of Colombia's Pacific coast: around Malpelo Island and in 2 National Natural Parks on the Colombian Pacific mainland (Sanquianga and Ensenada de Utría). We analyzed mtDNA control region (CR) sequences and genotyped 15 microsatellite loci in 137 samples of adults and juveniles. The mtDNA analyses showed haplotypes shared between the Colombian Pacific individuals sampled in this investigation and other areas in the Eastern Tropical Pacific, the Indo-Pacific, and with sequences previously reported in Colombia (Buenaventura Port), as well as 4 unique haplotypes. Population assignment and paternity analyses detected 3 parent-offspring pairs between Malpelo and Sanquianga and 1 between Malpelo and Utría. These results indicate high genetic connectivity between Malpelo Island and the Colombian Pacific coast, suggesting that these 2 areas are nurseries for S. lewini. This is, to our knowledge, the first evidence of nursery areas identified for the scalloped hammerhead shark anywhere in the world. Additional conservation planning may be required to protect these nursery habitats of this endangered shark species. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Effect of the Algaecide Palmitoleic Acid on the Immune Function of the Bay Scallop Argopecten irradians

    Directory of Open Access Journals (Sweden)

    Cheng Chi

    2016-05-01

    Full Text Available Palmitoleic acid (PA, an algicidal compound, is used against the toxin producing dinofagelate Alexandrium tamarense, however, its impact on the edible bay scallop (Argopecten irradians is still unclear. Therefore, we investigated the impacts of effective algicidal concentrations (20, 40, and 80 mg/L of PA on immune responses in A. irradians. Various immune parameters including acid phosphatase (ACP activity, superoxide dismutase (SOD, lysozyme, phagocytic activity, total protein, malondialdehyde (MDA level, and reactive oxygen species (ROS production and the expression of immune-related genes (PrxV, CLT-6, MT, and BD were measured at 3, 6, 12, 24, and 48 h post-exposure (hpe to PA. Lysozyme activity was lower in scallops at 12–48 hpe to 80 mg/L. SOD, ACP activity, ROS production, the total protein, and MDA level was higher at 12 to 48 hpe with different concentrations of PA. Phagocytic activity increased at 6–12 hpe to 40–80 mg/L of PA, but decreased at 24–48 hpe. The expressions of genes PrxV, CLT-6, MT and BD down-regulated at 3 hpe were observed, while differential expressions from 6–48 hpe with different concentrations of PA. The present study demonstrated that immersing A. irradians in PA at effective concentrations could result in differential effects on non-specific immune responses and expressions of immune-related genes.

  16. Formation of membrane ridges and scallops by the F-BAR protein Nervous Wreck.

    Science.gov (United States)

    Becalska, Agata N; Kelley, Charlotte F; Berciu, Cristina; Stanishneva-Konovalova, Tatiana B; Fu, Xiaofeng; Wang, Shiyu; Sokolova, Olga S; Nicastro, Daniela; Rodal, Avital A

    2013-08-01

    Eukaryotic cells are defined by extensive intracellular compartmentalization, which requires dynamic membrane remodeling. FER/Cip4 homology-Bin/amphiphysin/Rvs (F-BAR) domain family proteins form crescent-shaped dimers, which can bend membranes into buds and tubules of defined geometry and lipid composition. However, these proteins exhibit an unexplained wide diversity of membrane-deforming activities in vitro and functions in vivo. We find that the F-BAR domain of the neuronal protein Nervous Wreck (Nwk) has a novel higher-order structure and membrane-deforming activity that distinguishes it from previously described F-BAR proteins. The Nwk F-BAR domain assembles into zigzags, creating ridges and periodic scallops on membranes in vitro. This activity depends on structural determinants at the tips of the F-BAR dimer and on electrostatic interactions of the membrane with the F-BAR concave surface. In cells, Nwk-induced scallops can be extended by cytoskeletal forces to produce protrusions at the plasma membrane. Our results define a new F-BAR membrane-deforming activity and illustrate a molecular mechanism by which positively curved F-BAR domains can produce a variety of membrane curvatures. These findings expand the repertoire of F-BAR domain mediated membrane deformation and suggest that unique modes of higher-order assembly can define how these proteins sculpt the membrane.

  17. Oxidative and interactive challenge of cadmium and ocean acidification on the smooth scallop Flexopecten glaber.

    Science.gov (United States)

    Nardi, Alessandro; Benedetti, Maura; Fattorini, Daniele; Regoli, Francesco

    2018-03-01

    Ocean acidification (OA) may affect sensitivity of marine organisms to metal pollution modulating chemical bioavailability, bioaccumulation and biological responsiveness of several cellular pathways. In this study, the smooth scallop Flexopecten glaber was exposed to various combinations of reduced pH (pH/pCO 2 7.4/∼3000 μatm) and Cd (20 μg/L). The analyses on cadmium uptake were integrated with those of a wide battery of biomarkers including metallothioneins, single antioxidant defenses and total oxyradical scavenging capacity in digestive gland and gills, lysosomal membrane stability and onset of genotoxic damage in haemocytes. Reduced pH slightly increased concentration of Cd in scallop tissues, but no effects were measured in terms of metallothioneins. Induction of some antioxidants by Cd and/or low pH in the digestive gland was not reflected in variations of the total oxyradical scavenging capacity, while the investigated stressors caused a certain inhibition of antioxidants and reduction of the scavenging capacity toward peroxyl radical in the gills. Lysosomal membrane stability and onset of genotoxic damages showed high sensitivity with possible synergistic effects of the investigated factors. The overall results suggest that indirect effects of ocean acidification on metal accumulation and toxicity are tissue-specific and modulate oxidative balance through different mechanisms. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Effect of the Algaecide Palmitoleic Acid on the Immune Function of the Bay Scallop Argopecten irradians.

    Science.gov (United States)

    Chi, Cheng; Giri, Sib Sankar; Jun, Jin Woo; Kim, Hyoun Joong; Kim, Sang Guen; Yun, Saekil; Park, Se Chang

    2016-05-10

    Palmitoleic acid (PA), an algicidal compound, is used against the toxin producing dinofagelate Alexandrium tamarense, however, its impact on the edible bay scallop (Argopecten irradians) is still unclear. Therefore, we investigated the impacts of effective algicidal concentrations (20, 40, and 80 mg/L) of PA on immune responses in A. irradians. Various immune parameters including acid phosphatase (ACP) activity, superoxide dismutase (SOD), lysozyme, phagocytic activity, total protein, malondialdehyde (MDA) level, and reactive oxygen species (ROS) production and the expression of immune-related genes (PrxV, CLT-6, MT, and BD) were measured at 3, 6, 12, 24, and 48 h post-exposure (hpe) to PA. Lysozyme activity was lower in scallops at 12-48 hpe to 80 mg/L. SOD, ACP activity, ROS production, the total protein, and MDA level was higher at 12 to 48 hpe with different concentrations of PA. Phagocytic activity increased at 6-12 hpe to 40-80 mg/L of PA, but decreased at 24-48 hpe. The expressions of genes PrxV, CLT-6, MT and BD down-regulated at 3 hpe were observed, while differential expressions from 6-48 hpe with different concentrations of PA. The present study demonstrated that immersing A. irradians in PA at effective concentrations could result in differential effects on non-specific immune responses and expressions of immune-related genes.

  19. Oxidative stability of lipids rich in EPA and DHA extracted from fermented scallop ovary.

    Science.gov (United States)

    Hamaoka, Naohiro; Shimajiri, Junki; Abe, Masayuki; Hosokawa, Masashi; Miyashita, Kazuo

    2013-09-01

    A novel seafood paste was developed by the fermentation of scallop ovary using rice malt (koji) and yeast culture. Chemical analysis of the product showed the formation of high level of free amino acids and organic acids during the fermentation. The product color and flavor resembled to Japanese traditional soybean miso. The contents of total lipids (TLs) extracted from the fermented products were ranged from 9.18% to 11.59% or 11.38% to 13.57%/dry sample weight. Although the TL was rich in oxidatively unstable polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), little decrease was found in these PUFAs during the fermentation, showing the high oxidative stability of the TL from the fermented scallop ovary. Moreover, the oxidative stability of the TL extracted from the fermented products increased with increasing the fermentation time. This would be mainly due to the formation of lipid soluble antioxidants such as tocopherols, which might be derived from yeast used for fermentation. © 2013 Institute of Food Technologists®

  20. Space utilisation patterns of bryozoans on the Patagonian scallop Psychrochlamys patagonica

    Directory of Open Access Journals (Sweden)

    Juan López Gappa

    2009-03-01

    Full Text Available We studied the bryozoan assemblage encrusting valves of the Patagonian scallop, Psychrochlamys patagonica, in 4 beds distributed along the continental shelf off Argentina to analyse (a the distribution pattern of bryozoan colonies in different zones of the valves, (b the influence of interspecific competition on assemblage composition, (c whether encrusting species display different space utilisation strategies, and (d whether bryozoan species richness and number of colonies vary in relation to host size. The assemblage was composed of 22 taxa and was dominated by Arachnopusia monoceros and Osthimosia eatonensis, which were at least one order of magnitude more abundant than any other species. Multivariate analyses based on coverage data of multiserial bryozoans separated the beds according to species richness rather than to geographic proximity and showed significant differences in assemblage structure between upper (left and lower (right valves and among beds. Competitive interactions occurred almost exclusively on lower valves, and more frequently in peripheral zones than in central zones of these valves. Correlations between valve area and number of bryozoan colonies, coverage and species richness were low but significant. Bryozoans were significantly more frequent, larger, and taxonomically diverse on lower valves than on upper valves. The uniserial colonies of Neothoa cf. chiloensis, the weakest bryozoan competitor, were as frequent in central zones as they were in peripheral zones, and usually spread out along channels on the scallop surface. This fugitive species was partially covered by multiserial colonies, but managed to persist even in peripheral areas of the lower valves.

  1. An Integrated Assessment Model for Helping the United States Sea Scallop (Placopecten magellanicus) Fishery Plan Ahead for Ocean Acidification and Warming.

    Science.gov (United States)

    Cooley, Sarah R; Rheuban, Jennie E; Hart, Deborah R; Luu, Victoria; Glover, David M; Hare, Jonathan A; Doney, Scott C

    2015-01-01

    Ocean acidification, the progressive change in ocean chemistry caused by uptake of atmospheric CO2, is likely to affect some marine resources negatively, including shellfish. The Atlantic sea scallop (Placopecten magellanicus) supports one of the most economically important single-species commercial fisheries in the United States. Careful management appears to be the most powerful short-term factor affecting scallop populations, but in the coming decades scallops will be increasingly influenced by global environmental changes such as ocean warming and ocean acidification. In this paper, we describe an integrated assessment model (IAM) that numerically simulates oceanographic, population dynamic, and socioeconomic relationships for the U.S. commercial sea scallop fishery. Our primary goal is to enrich resource management deliberations by offering both short- and long-term insight into the system and generating detailed policy-relevant information about the relative effects of ocean acidification, temperature rise, fishing pressure, and socioeconomic factors on the fishery using a simplified model system. Starting with relationships and data used now for sea scallop fishery management, the model adds socioeconomic decision making based on static economic theory and includes ocean biogeochemical change resulting from CO2 emissions. The model skillfully reproduces scallop population dynamics, market dynamics, and seawater carbonate chemistry since 2000. It indicates sea scallop harvests could decline substantially by 2050 under RCP 8.5 CO2 emissions and current harvest rules, assuming that ocean acidification affects P. magellanicus by decreasing recruitment and slowing growth, and that ocean warming increases growth. Future work will explore different economic and management scenarios and test how potential impacts of ocean acidification on other scallop biological parameters may influence the social-ecological system. Future empirical work on the effect of ocean

  2. An Integrated Assessment Model for Helping the United States Sea Scallop (Placopecten magellanicus Fishery Plan Ahead for Ocean Acidification and Warming.

    Directory of Open Access Journals (Sweden)

    Sarah R Cooley

    Full Text Available Ocean acidification, the progressive change in ocean chemistry caused by uptake of atmospheric CO2, is likely to affect some marine resources negatively, including shellfish. The Atlantic sea scallop (Placopecten magellanicus supports one of the most economically important single-species commercial fisheries in the United States. Careful management appears to be the most powerful short-term factor affecting scallop populations, but in the coming decades scallops will be increasingly influenced by global environmental changes such as ocean warming and ocean acidification. In this paper, we describe an integrated assessment model (IAM that numerically simulates oceanographic, population dynamic, and socioeconomic relationships for the U.S. commercial sea scallop fishery. Our primary goal is to enrich resource management deliberations by offering both short- and long-term insight into the system and generating detailed policy-relevant information about the relative effects of ocean acidification, temperature rise, fishing pressure, and socioeconomic factors on the fishery using a simplified model system. Starting with relationships and data used now for sea scallop fishery management, the model adds socioeconomic decision making based on static economic theory and includes ocean biogeochemical change resulting from CO2 emissions. The model skillfully reproduces scallop population dynamics, market dynamics, and seawater carbonate chemistry since 2000. It indicates sea scallop harvests could decline substantially by 2050 under RCP 8.5 CO2 emissions and current harvest rules, assuming that ocean acidification affects P. magellanicus by decreasing recruitment and slowing growth, and that ocean warming increases growth. Future work will explore different economic and management scenarios and test how potential impacts of ocean acidification on other scallop biological parameters may influence the social-ecological system. Future empirical work on the

  3. 76 FR 72891 - Endangered and Threatened Wildlife; 90-Day Finding on a Petition To List the Scalloped Hammerhead...

    Science.gov (United States)

    2011-11-28

    ... standards on extinction risk and impacts or threats discussed above. Distribution and Life History of the... WildEarth Guardians and Friends of Animals to list the scalloped hammerhead shark (Sphyrna lewini) as..., or DPS is ``endangered'' if it is in danger of extinction throughout all or a significant portion of...

  4. A new species of living scallop of the genus Anguipecten (Bivalvia, Pectinidae) from the tropical Indo-Pacific

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2002-01-01

    Introduction During the Indonesian-French Karubar cruise to eastern Indonesia a new scallop was found near the Kai Islands, which was provisionally identified by Dijkstra & Kastoro(1997: 279, figs 156-159), based on a few dead specimens from the upper bathyal depths. Subsequently, more material was

  5. Seasonal variability of Protoceratium reticulatum and yessotoxins in Japanese scallop Patinopecten yessoensis in northern Yellow Sea of China.

    Science.gov (United States)

    Liu, Lei; Wei, Ning; Gou, Yuxiao; Li, Dongmei; Liang, Yubo; Xu, Daoyan; Liu, Renyan; Sui, Shifeng; Jiang, Tianjiu

    2017-12-01

    This paper reports a toxic strain of Protoceratium reticulatum, its morphology, phylogeny, yessotoxins (YTXs) production and abundance in northern Yellow Sea of China from 2011 to 2015 was investigated. YTXs in hepatopancreas and edible parts of bottom sowing cultured Japanese scallop Patinopecten yessoensis in this sea area were determined weekly for 5 years. Other potential producers of YTXs, Gonyaulax spinifera and Lingulodinium polyedrum, were also investigated. Results revealed that Protoceratium reticulatum strain from the northern Yellow Sea belongs to a geographically widely distributed species. Motile cells of Protoceratium reticulatum contribute to YTXs in Japanese scallop, and G. spinifera may also be a potential contributor. Resting cysts of Protoceratium reticulatum, G. spinifera, and L. polyedrum in sediments were possibly important origins of YTXs in scallop cultured at sea bottom. YTXs in scallop decreased from 2011 to 2015, most toxins were concentrated in hepatopancreas, while a small portion in edible parts which was safe for consumption the whole year around. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Molecular characterization and protein localization of the antimicrobial peptide big defensin from the scallop Argopecten purpuratus after Vibrio splendidus challenge.

    Science.gov (United States)

    González, Roxana; Brokordt, Katherina; Cárcamo, Claudia B; Coba de la Peña, Teodoro; Oyanedel, Daniel; Mercado, Luis; Schmitt, Paulina

    2017-09-01

    Big defensins are antimicrobial peptides (AMPs) that are proposed as important effectors of the immune response in mollusks, chelicerates and chordates. At present, only two members of the big defensin family have been identified in scallop. In the present work, a cDNA sequence encoding a new big defensin homologue was characterized from the scallop Argopecten purpuratus, namely ApBD1. ApBD1 cDNA sequence comprised 585 nucleotides, with an open reading frame of 375 bp and 5'- and 3'-UTRs of 41 and 167 bp, respectively. The deduced protein sequence contains 124 amino acids with a molecular weight of 13.5 kDa, showing characteristic motifs of the big defensin family and presenting 76% identity with the big defensin from the scallop A. irradians. Phylogenetic analysis revealed that ApBD1 is included into the cluster of big defensins from mollusks. Tissue-specific transcript expression analysis by RT-qPCR showed that ApBD1 was present in all tissues tested from non-immune challenged scallops but it was most strongly expressed in the mantle. The transcript levels of ApBD1 were significantly up-regulated in gills at 24 and 48 h post-injection with the heat-attenuated bacteria Vibrio splendidus. Additionally, immunofluorescence analysis using a polyclonal anti-ApBD1 antibody showed that this protein was abundantly located in epithelial linings of gills and mantle; and also in digestive gland showing ApBD1-infiltrating hemocytes from immune challenged scallops. This is the first time that a big defensin is detected and located at the protein level in a mollusk. These results suggest an important role of ApBD1 in the mucosal immune response of A. purpuratus. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Antagonizing scalloped with a novel vestigial construct reveals an important role for scalloped in Drosophila melanogaster leg, eye and optic lobe development.

    Science.gov (United States)

    Garg, Ankush; Srivastava, Ajay; Davis, Monica M; O'Keefe, Sandra L; Chow, Leola; Bell, John B

    2007-02-01

    Scalloped (SD), a TEA/ATTS-domain-containing protein, is required for the proper development of Drosophila melanogaster. Despite being expressed in a variety of tissues, most of the work on SD has been restricted to understanding its role and function in patterning the adult wing. To gain a better understanding of its role in development, we generated sd(47M) flip-in mitotic clones. The mitotic clones had developmental defects in the leg and eye. Further, by removing the VG domains involved in activation, we created a reagent (VGDeltaACT) that disrupts the ability of SD to form a functional transcription factor complex and produced similar phenotypes to the flip-in mitotic clones. The VGDeltaACT construct also disrupted adult CNS development. Expression of the VGDeltaACT construct in the wing alters the cellular localization of VG and produces a mutant phenotype, indicating that the construct is able to antagonize the normal function of the SD/VG complex. Expression of the protein:protein interaction portion of SD is also able to elicit similar phenotypes, suggesting that SD interacts with other cofactors in the leg, eye, and adult CNS. Furthermore, antagonizing SD in larval tissues results in cell death, indicating that SD may also have a role in cell survival.

  8. Seasonal influence of scallop culture on nutrient flux, bacterial pathogens and bacterioplankton diversity across estuaries off the Bohai Sea Coast of Northern China.

    Science.gov (United States)

    He, Yaodong; Sen, Biswarup; Shang, Junyang; He, Yike; Xie, Ningdong; Zhang, Yongfeng; Zhang, Jianle; Johnson, Zackary I; Wang, Guangyi

    2017-11-15

    In this study, we investigated the environmental impacts of scallop culture on two coastal estuaries adjacent the Bohai Sea including developing a quantitative PCR assay to assess the abundance of the bacterial pathogens Escherichia coli and Vibrio parahaemolyticus. Scallop culture resulted in a significant reduction of nitrogen, Chlorophyll a, and phosphorous levels in seawater during summer. The abundance of bacteria including V. parahaemolyticus varied significantly across estuaries and breeding seasons and was influenced by nitrate as well as nutrient ratios (Si/DIN, N/P). Bacterioplankton diversity varied across the two estuaries and seasons, and was dominated by Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes. Overall, this study suggests a significant influence of scallop culture on the ecology of adjacent estuaries and offers a sensitive tool for monitoring scallop contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. De Novo Assembly and Characterization of Two Transcriptomes Reveal Multiple Light-Mediated Functions in the Scallop Eye (Bivalvia: Pectinidae): e69852

    National Research Council Canada - National Science Library

    Autum N Pairett; Jeanne M Serb

    2013-01-01

    ... function of this group, which is due, in part, to a lack of genomic resources. The scallop (Bivalvia: Pectinidae) represents a compeling molluscan model to study photoreception due to its morphologically novel and separately evolved mirror-type eye...

  10. Complete mitochondrial genome of the scalloped hammerhead Sphyrna lewini (Carcharhiniformes: Sphyrnidae).

    Science.gov (United States)

    Chen, Xiao; Xiang, Dan; Xu, Yuziwei; Shi, Xiaofang

    2015-08-01

    The complete mitochondrial genome of the endangered scalloped hammerhead Sphyrna lewini was firstly determined in this study. It is 16,726 bp in length with the typical gene composition and orders in vertebrates. The overall base composition is 31.4% A, 26.3% C, 13.2% G and 29.1% T. Two start codon (ATG and GTG) and three stop codon (TAG, AGA and TAA/TA/T) patterns were found in protein-coding genes. Except for the tRNA-Ser2, the remaining 21 tRNAs can be folded into the typical cloverleaf structure. The control region possess the highest A + T content (66.1%) and lowest G content (12.6%) among all mitochondrial partitions.

  11. New microsatellite loci for the endangered scalloped hammerhead shark, Sphyrna lewini.

    Science.gov (United States)

    Nance, Holly A; Daly-Engel, Toby S; Marko, Peter B

    2009-05-01

    We isolated 15 microsatellite markers for the scalloped hammerhead shark, Sphyrna lewini. Loci were tested on 80 specimens of S. lewini from four Eastern Pacific samples. The number of alleles per locus ranged from 6 to 31 (mean = 14). Observed and expected levels of heterozygosity per locus ranged from 0.39 to 0.91 (mean = 0.70) and from 0.54 to 0.90 (mean = 0.76), respectively. No pairs of loci were in gametic disequilibrium after Bonferroni correction of α. One locus showed significantly lower heterozygosity than expected under Hardy-Weinberg proportions in two populations, possibly caused by null alleles. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Ltd.

  12. Maternal offloading of organochlorine contaminants in the yolk-sac placental scalloped hammerhead shark (Sphyrna lewini).

    Science.gov (United States)

    Lyons, Kady; Adams, Douglas H

    2015-04-01

    Elasmobranchs are a group of animals that typically occupy upper trophic levels in food webs and have a propensity to accumulate high contaminant concentrations. To date, few studies have investigated maternal offloading processes in sharks, despite the fact that this process represents a substantial source of exposure for young sharks and is a significant pathway for contaminant redistribution within marine ecosystems. Comparable to mammalian systems, scalloped hammerhead sharks (Sphyrna lewini) utilize a yolk-sac placental strategy to nourish young in utero, which may allow females to transfer contaminants to young. Organic contaminants (PCBs and chlorinated pesticides) were measured in livers of both females and males from several age classes that were collected from U.S. Atlantic waters, including two near-term pregnant females and their embryos. Adult female hammerheads (n = 3) were found to have lower levels of PCBs compared to the younger, adult male (mean ± SD, 11.1 ± 1.0 vs. 22.8 μg g(-1) lw), but had substantially higher concentrations of pesticides (4.1 ± 0.9 vs. 1.9 μg g(-1) lw). Embryos from the two litters (n = 36) had similar levels of summed organic contaminant concentrations (4.6 ± 0.9 μg g(-1) lw) and pregnant females were estimated to offload approximately 0.03-2.3% of their hepatic contaminant load to offspring. While the potential health impacts of these transferred contaminants is unknown, this is the first study to demonstrate that scalloped hammerheads are exposed to a substantial amount of contaminants prior to birth and document maternal offloading of organochlorines in a pseudo-placental shark species. Therefore, future research should continue to investigate the potential adverse effects these contaminants have on elasmobranch physiology.

  13. Feeding and energetics of the great scallop, Pecten maximus, through a DEB model

    Science.gov (United States)

    Lavaud, Romain; Flye-Sainte-Marie, Jonathan; Jean, Fred; Emmery, Antoine; Strand, Øivind; Kooijman, Sebastiaan A. L. M.

    2014-11-01

    We developed a full life-cycle bioenergetic model for the great scallop Pecten maximus relying on the concepts of the Dynamic Energy Budget (DEB) theory. The covariation method was implemented to estimate the parameters of a standard DEB model. Such models are able to predict various metabolic processes from a food availability marker and temperature in the environment. However, suspension-feeders are likely to feed on various trophic sources, from microalgae cells to detritus. They are also able to sort and select food particles very efficiently, depending on their size, energetic value or quality. The present model includes a mechanistic description of the feeding processes, based on Kooijman's Synthesizing Unit principle which allows to deal with several food sources. Moreover we tested the hypothesis of a differential selectivity between two potential substrates (phytoplankton cell and the remaining particulate organic matter). Simulations of shell length, daily shell growth rate, dry weight and gonado-somatic index (GSI) variations were realized and compared to field data from a monitoring conducted in the Bay of Brest (Brittany, France) for six years. The model shows its capacity to efficiently reproduce all life history traits of the wild great scallops. Predicted length data were estimated to the nearest millimeter. The fit of simulated weights to observed data was very satisfactory. GSI predictions were also in accordance with observations but improvements are required to better capture the sharp increase of gametogenesis at the beginning of the year. Finally, results bring evidences that P. maximus is actually preferentially feed on living algae cells rather than on the rest of organic particles.

  14. Pre- And Postharvest Nutritional Value And Storage Ability Of Scallop Squash Cultivars

    Directory of Open Access Journals (Sweden)

    Balbierz Agnieszka

    2015-12-01

    Full Text Available Scallop squash fruit may be harvested and supplied to the fresh market at different stages of maturity. However, small size and immature fruit, preferred by the consumers and food industry, have only a limited storage life, which duration, among others, depends on cultivar characteristic. The objective of the study was to evaluate the storage ability and pre- and postharvest nutritional value of small size fruit of ‘Disco’, ‘Polo F1’, ‘Sunny Delight F1’, ‘Gagat’ and ‘Okra’ scallop squash cultivars. Fruit with diameter 3-6 cm, harvested at the time of maximum fruiting, were placed in the storage room with temperature 7 ºC, and relative humidity > 95% for the period of 1 or 2 weeks. Results of the study showed that prolonged up to 14 days period of fruit storage caused a drastic, within 9.95% – 13.95% weight loss, which was associated with visual symptoms of wilting and significant decrease of dry matter, sugars, vitamin C, carotenoids and nitrates contents. Among examined cultivars, the best suitable for the short storage, lasted no longer than 7 days, appeared to be ‘Disco’ and ‘Okra’. ‘Sunny Delight F1’, the only one cultivar with yellow color of skin, containing high amounts of vitamin C and polyphenols and showing low tendency to nitrates accumulation, similarly as ‘Gagat’ and ‘Polo F1’, were less suitable for short period of cold storage.

  15. Sex Reversal and Analyses of Possible Involvement of Sex Steroids in Scallop Gonadal Development in Newly Established Organ-Culture Systems.

    Science.gov (United States)

    Otani, Ayano; Nakajima, Tadaaki; Okumura, Tomomi; Fujii, Shiro; Tomooka, Yasuhiro

    2017-04-01

    Many molluscs perform sex reversal, and sex hormones may be involved in the process. In adult scallops, Patinopecten yessoensis, gonadotropin releasing hormone and 17β-estradiol (E 2 ) are involved in male sexual maturation, however, little is known about the effects of E 2 and testosterone (T) on the gonadal differentiation in young scallops. In the present study, scallop gonadal development was analyzed to determine the sex reversal stage in Funka bay, and effects of E 2 and T were examined. In Funka bay, almost all scallops were male at month 12. Scallops equipped with ambiguous gonads were 61.1% at month 16 and disappeared at month 18. Therefore, sex reversal in Funka bay occurs at around month 16. For establishment of organ culture systems for bivalves, Manila clam gonads were cultured in 15% L-15 medium diluted with HBSS containing 10% KSR on agarose gel at 10°C, and the gonads survived for 14 days. Scallop gonads were also able to be cultured in 30% L15 medium diluted with ASW containing 10% KSR on agarose gel for seven days. At mature stage, Foxl2 and Tesk were predominantly expressed in ovary and testis, respectively. When scallop gonads at sex reversal stage were organ-cultured, sex steroid treatment decreased Tesk expression in the majority of scallop gonads at sex reversal stage. However, no obvious change in Foxl2 and Tesk expression was detected in mature gonads in response to either E 2 or T in culture, suggesting sex steroid treatment might affect gonadal development at sex reversal stage.

  16. Viruses infecting marine molluscs.

    Science.gov (United States)

    Arzul, Isabelle; Corbeil, Serge; Morga, Benjamin; Renault, Tristan

    2017-07-01

    Although a wide range of viruses have been reported in marine molluscs, most of these reports rely on ultrastructural examination and few of these viruses have been fully characterized. The lack of marine mollusc cell lines restricts virus isolation capacities and subsequent characterization works. Our current knowledge is mostly restricted to viruses affecting farmed species such as oysters Crassostrea gigas, abalone Haliotis diversicolor supertexta or the scallop Chlamys farreri. Molecular approaches which are needed to identify virus affiliation have been carried out for a small number of viruses, most of them belonging to the Herpesviridae and birnaviridae families. These last years, the use of New Generation Sequencing approach has allowed increasing the number of sequenced viral genomes and has improved our capacity to investigate the diversity of viruses infecting marine molluscs. This new information has in turn allowed designing more efficient diagnostic tools. Moreover, the development of experimental infection protocols has answered some questions regarding the pathogenesis of these viruses and their interactions with their hosts. Control and management of viral diseases in molluscs mostly involve active surveillance, implementation of effective bio security measures and development of breeding programs. However factors triggering pathogen development and the life cycle and status of the viruses outside their mollusc hosts still need further investigations. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Iodothyronine deiodinase gene analysis of the Pacific oyster Crassostrea gigas reveals possible conservation of thyroid hormone feedback regulation mechanism in mollusks

    Science.gov (United States)

    Huang, Wen; Xu, Fei; Qu, Tao; Li, Li; Que, Huayong; Zhang, Guofan

    2015-07-01

    Iodothyronine deiodinase catalyzes the initiation and termination of thyroid hormones (THs) effects, and plays a central role in the regulation of thyroid hormone level in vertebrates. In non-chordate invertebrates, only one deiodinase has been identified in the scallop Chlamys farreri. Here, two deiodinases were cloned in the Pacific oyster Crassostrea gigas ( CgDx and CgDy). The characteristic in-frame TGA codons and selenocysteine insertion sequence elements in the oyster deiodinase cDNAs supported the activity of them. Furthermore, seven orthologs of deiodinases were found by a tblastn search in the mollusk Lottia gigantea and the annelid Capitella teleta. A phylogenetic analysis revealed that the deiodinase gene originated from an common ancestor and a clade-specific gene duplication occurred independently during the differentiation of the mollusk, annelid, and vertebrate lineages. The distinct spatiotemporal expression patterns implied functional divergence of the two deiodinases. The expression of CgDx and CgDy was influenced by L-thyroxine T4, and putative thyroid hormone responsive elements were found in their promoters, which suggested that the oyster deiodinases were feedback regulated by TH. Epinephrine stimulated the expression level of CgDx and CgDy, suggesting an interaction effect between different hormones. This study provides the first evidence for the existence of a conserved TH feedback regulation mechanism in mollusks, providing insights into TH evolution.

  18. Fisheries Closed Areas Strengthen Scallop Larval Settlement and Connectivity Among Closed Areas and Across International Open Fishing Grounds: A Model Study.

    Science.gov (United States)

    Davies, Kimberley T A; Gentleman, W C; DiBacco, C; Johnson, C L

    2015-09-01

    This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological-physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.

  19. Regional variation in undulatory kinematics of two hammerhead species: the bonnethead (Sphyrna tiburo) and the scalloped hammerhead (Sphyrna lewini).

    Science.gov (United States)

    Hoffmann, Sarah L; Warren, Steven M; Porter, Marianne E

    2017-09-15

    Hammerhead sharks (Sphyrnidae) exhibit a large amount of morphological variation within the family, making them the focus of many studies. The size of the laterally expanded head, or cephalofoil, is inversely correlated with pectoral fin area. The inverse relationship between cephalofoil and pectoral fin size in this family suggests that they might serve a complementary role in lift generation. The cephalofoil is also hypothesized to increase olfaction, electroreception and vision; however, little is known about how morphological variation impacts post-cranial swimming kinematics. Previous studies demonstrate that the bonnethead and scalloped hammerhead have significantly different yaw amplitude, and we hypothesized that these species utilize varied frequency and amplitude of undulation along the body. We analyzed video of free-swimming sharks to examine kinematics and 2D morphological variables of the bonnethead and scalloped hammerhead. We also examined the second moment of area along the length of the body and over a size range of animals to determine whether there were shape differences along the body of these species and whether those changed over ontogeny. We found that both species swim with the same standardized velocity and Strouhal number, but there was no correlation between two-dimensional morphology and swimming kinematics. However, the bonnethead has a dorso-ventrally compressed anterior trunk and undulates with greater amplitude, whereas the scalloped hammerhead has a laterally compressed anterior trunk and undulates with lower amplitude. We propose that differences in cross-sectional trunk morphology account for interspecific differences in undulatory amplitude. We also found that for both species, undulatory frequency is significantly greater in the anterior body compared with all other body regions. We hypothesize that the bonnethead and scalloped hammerhead swim with a double oscillation system. © 2017. Published by The Company of Biologists Ltd.

  20. Feeding strategy of the night shark (Carcharhinus signatus) and scalloped hammerhead shark (Sphyrna lewini) near seamounts off northeastern Brazil

    OpenAIRE

    Teodoro Vaske Júnior; Carolus Maria Vooren; Rosangela Paula Lessa

    2009-01-01

    A total of 425 stomachs of night shark (Carcharhinus signatus), and 98 stomachs of scalloped hammerhead shark (Sphyrna lewini), from longline and surface gillneters near seamounts off northeastern Brazil, were analysed between 1992 and 1999. Both predators prey upon reef and benthopelagic fishes, migrant cephalopods and deep water crustaceans, showing similar feeding niches (Schoener Index T=0.75). The great prey richness of the diets may reflect the fact that the marine food web for these sp...

  1. A Marriage Of Larval Modeling And Empirical Data: Linking Adult, Larval And Juvenile Scallops In An Estuary

    Science.gov (United States)

    Bayer, S.; Wahle, R.; Brooks, D. A.; Brady, D. C.

    2016-02-01

    The giant sea scallop, Placopecten magellanicus, is a commercially valuable sedentary broadcast spawner that occupies offshore banks and coastal bays and estuaries in the Northwest Atlantic. Although area closures have helped repopulate depleted scallop populations, little is known about whether populations at densities that yield larvae supply local or distant populations. Surveying scallop populations in the Damariscotta River estuary in Maine during the 2013 and 2014 spawning seasons, and settling out spat bags to collect settling larvae along the gradient of the estuary, we were able to compare adult densities to newly settled juvenile (`spat') abundance. Using the location where we found a high density of adults, we incorporated previously published behavior, pelagic larval duration, wind and current data into a particle dispersal model within the estuary to determine likely sinks for larvae from the 2013 and 2014 spawning seasons. Preliminary model simulations demonstrate where in the estuary swimming is effective in affecting water column position for larvae, and that most larvae are retained much closer to the mouth of the estuary than previously expected. Combining larval dispersal modeling with empirical data on adult densities and spat settlement on the scale of an embayment or estuary may be helpful in determining sources, sinks and areas that are both sources and sinks for shellfish species that are endangered or economically critical. This may aid in determining small area closures or Marine Protected Areas along coastal regions in the Gulf of Maine and beyond.

  2. Genetic Differentiation between Natural and Hatchery Stocks of Japanese Scallop (Mizuhopecten yessoensis as Revealed by AFLP Analysis

    Directory of Open Access Journals (Sweden)

    Zhan-Jiang Liu

    2010-10-01

    Full Text Available Japanese scallop (Mizuhopecten yessoensis is a cold-tolerant bivalve that was introduced to China for aquaculture in 1982. In this study, amplified fragment length polymorphism (AFLP markers were used to investigate levels of genetic diversity within M. yessoensis cultured stocks and compare them with wild populations. Six pairs of primer combinations generated 368 loci among 332 individuals, in four cultured and three wild populations. High polymorphism at AFLP markers was found within both cultured and wild M. yessoensis populations. The percentage of polymorphic loci ranged from 61.04% to 72.08%, while the mean heterozygosity ranged from 0.2116 to 0.2596. Compared with wild populations, the four hatchery populations showed significant genetic changes, such as lower expected heterozygosity and percentage of polymorphic loci, and smaller frequency of private alleles, all indicative of a reduction in genetic diversity. Some genetic structures were associated with the geographical distribution of samples; with all samples from Dalian and Japan being closely related, while the population from Russia fell into a distinct clade in the phylogenetic analysis. The genetic information derived from this study indicated that intentional or accidental release of selected Japanese scallops into natural sea areas might result in disturbance of local gene pools and loss of genetic variability. We recommend monitoring the genetic variability of selected hatchery populations to enhance conservation of natural Japanese scallop resources.

  3. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Science.gov (United States)

    Singh, Warsha; Örnólfsdóttir, Erla B; Stefansson, Gunnar

    2014-01-01

    An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in <2% error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.

  4. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Directory of Open Access Journals (Sweden)

    Warsha Singh

    Full Text Available An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in <2% error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.

  5. Asymmetric hemoglobins, their thiol content, and blood glutathione of the scalloped hammerhead shark, Sphyrna lewini.

    Science.gov (United States)

    Dafré, A L; Reischl, E

    1997-03-01

    Starch gel electrophoresis pH 8.6, or PAGE pH 8.9, of the scalloped hammerhead shark hemolysates showed three hemoglobins (Hb). An additional Hb between the two most mobile electrophoretic components was seen in starch gel electrophoresis, pH 8.1, and also in highly loaded PAGE gels. The relative concentration of these Hbs was variable among individuals, when accessed at pH 8.1. Dilution of hemolysates led to a redistribution of the Hb tetramer subunits. Under denaturing conditions, the unfractionated hemolysate was resolved in 3 Hb subunits. Isolated Hbs, named SL I-SL IV, showed unusual subunit compositions: SL I, the least mobile, is "b3c"; SL II is "a2bc"; SL III and SL IV are composed only by "a" subunits. Hemoglobins in the whole hemolysate have an average of two reactive cysteines per tetramer, which were not easily S-thiolated by glutathione, as is the case for related species. After hemoglobin denaturation, six additional -SH groups were titrated by Ellman's reagent. Methemoglobin content was low in the erythrocytes of nine examined specimens, 1.13 +/- 1.90%. High values for total erythrocyte glutathione (GSH) were found: 4.5 +/- 0.7 mM; n = 7. The ratio of 1.4 +/- 0.4 GSH/Hb is higher than usually reported for mammalians.

  6. Molecular and functional analysis of scalloped recessive lethal alleles in Drosophila melanogaster.

    Science.gov (United States)

    Srivastava, Ajay; Simmonds, Andrew J; Garg, Ankush; Fossheim, Leif; Campbell, Shelagh D; Bell, John B

    2004-04-01

    The Drosophila melanogaster scalloped (sd) gene is a homolog of the human TEF-1 gene and is a member of the TEA/ATTS domain-containing family of transcription factors. In Drosophila, sd is involved in wing development as well as neural development. Herein, data are presented from a molecular analysis of five recessive lethal sd alleles. Only one of these alleles complements a viable allele associated with an sd mutant wing phenotype, suggesting that functions important for wing development are compromised by the noncomplementing alleles. Two of the wing noncomplementing alleles have mutations that help to define a VG-binding domain for the SD protein in vivo, and another noncomplementing allele has a lesion within the TEA DNA-binding domain. The VG-binding domain overlaps with a domain important for viability of the fly, since two of the sd lethal lesions are located there. The fifth lethal affects a yet undefined motif lying just outside the VG-binding domain in the C-terminal direction that affects both wing phenotype and viability. This is the first example linking mutations affecting specific amino acids in the SD protein with phenotypic consequences for the organism.

  7. Adaptive scallop height tool path generation for robot-based incremental sheet metal forming

    Science.gov (United States)

    Seim, Patrick; Möllensiep, Dennis; Störkle, Denis Daniel; Thyssen, Lars; Kuhlenkötter, Bernd

    2016-10-01

    Incremental sheet metal forming is an emerging process for the production of individualized products or prototypes in low batch sizes and with short times to market. In these processes, the desired shape is produced by the incremental inward motion of the workpiece-independent forming tool in depth direction and its movement along the contour in lateral direction. Based on this shape production, the tool path generation is a key factor on e.g. the resulting geometric accuracy, the resulting surface quality, and the working time. This paper presents an innovative tool path generation based on a commercial milling CAM package considering the surface quality and working time. This approach offers the ability to define a specific scallop height as an indicator of the surface quality for specific faces of a component. Moreover, it decreases the required working time for the production of the entire component compared to the use of a commercial software package without this adaptive approach. Different forming experiments have been performed to verify the newly developed tool path generation. Mainly, this approach serves to solve the existing conflict of combining the working time and the surface quality within the process of incremental sheet metal forming.

  8. Genomic consequences of background effects on scalloped mutant expressivity in the wing of Drosophila melanogaster.

    Science.gov (United States)

    Dworkin, Ian; Kennerly, Erin; Tack, David; Hutchinson, Jennifer; Brown, Julie; Mahaffey, James; Gibson, Greg

    2009-03-01

    Genetic background effects contribute to the phenotypic consequences of mutations and are pervasive across all domains of life that have been examined, yet little is known about how they modify genetic systems. In part this is due to the lack of tractable model systems that have been explicitly developed to study the genetic and evolutionary consequences of background effects. In this study we demonstrate that phenotypic expressivity of the scalloped(E3) (sd(E3)) mutation of Drosophila melanogaster is background dependent and is the result of at least one major modifier segregating between two standard lab wild-type strains. We provide evidence that at least one of the modifiers is linked to the vestigial region and demonstrate that the background effects modify the spatial distribution of known sd target genes in a genotype-dependent manner. In addition, microarrays were used to examine the consequences of genetic background effects on the global transcriptome. Expression differences between wild-type strains were found to be as large as or larger than the effects of mutations with substantial phenotypic effects, and expression differences between wild type and mutant varied significantly between genetic backgrounds. Significantly, we demonstrate that the epistatic interaction between sd(E3) and an optomotor blind mutation is background dependent. The results are discussed within the context of developing a complex but more realistic view of the consequences of genetic background effects with respect to mutational analysis and studies of epistasis and cryptic genetic variation segregating in natural populations.

  9. Alternative requirements for Vestigial, Scalloped, and Dmef2 during muscle differentiation in Drosophila melanogaster.

    Science.gov (United States)

    Deng, Hua; Hughes, Sarah C; Bell, John B; Simmonds, Andrew J

    2009-01-01

    Vertebrate development requires the activity of the myocyte enhancer factor 2 (mef2) gene family for muscle cell specification and subsequent differentiation. Additionally, several muscle-specific functions of MEF2 family proteins require binding additional cofactors including members of the Transcription Enhancing Factor-1 (TEF-1) and Vestigial-like protein families. In Drosophila there is a single mef2 (Dmef2) gene as well single homologues of TEF-1 and vestigial-like, scalloped (sd), and vestigial (vg), respectively. To clarify the role(s) of these factors, we examined the requirements for Vg and Sd during Drosophila muscle specification. We found that both are required for muscle differentiation as loss of sd or vg leads to a reproducible loss of a subset of either cardiac or somatic muscle cells in developing embryos. This muscle requirement for Sd or Vg is cell specific, as ubiquitous overexpression of either or both of these proteins in muscle cells has a deleterious effect on muscle differentiation. Finally, using both in vitro and in vivo binding assays, we determined that Sd, Vg, and Dmef2 can interact directly. Thus, the muscle-specific phenotypes we have associated with Vg or Sd may be a consequence of alternative binding of Vg and/or Sd to Dmef2 forming alternative protein complexes that modify Dmef2 activity.

  10. Further developmental roles of the Vestigial/Scalloped transcription complex during wing development in Drosophila melanogaster.

    Science.gov (United States)

    Srivastava, Ajay; Bell, John B

    2003-05-01

    The Drosophila homologue of the human TEF-1 gene, scalloped (sd), is required for wing development. The SD protein forms part of a transcriptional activation complex with the protein encoded by vestigial (vg) that, in turn, activates target genes important for wing formation. One sd function involves a regulatory feedback loop with vg and wingless (wg) that is essential in this process. The dorsal-ventral (D/V) margin-specific expression of wg is lost in sd mutant wing discs while the hinge-specific expression appears normal. In the context of wing development, a VG::sdTEA domain fusion produces a protein that mimics the wild-type SD/VG complex and restores the D/V boundary-specific expression of wg in a sd mutant background. Further, targeted expression of wg at the D/V boundary in the wing disc was able to partially rescue the sd mutant phenotype. This infers that sd could function in either the maintenance or induction of wg at the D/V border. Another functional role for sd is the establishment of sensory organ precursors (SOP) of the peripheral nervous system at the wing margin. Thus, the relationship between sd and senseless (sens) in the development of these cells is also examined, and it appears that sd must be functional for proper sens expression, and ultimately, for sensory organ precursor development.

  11. Specific interactions between vestigial and scalloped are required to promote wing tissue proliferation in Drosophila melanogaster.

    Science.gov (United States)

    Paumard-Rigal, S; Zider, A; Vaudin, P; Silber, J

    1998-10-01

    The two genes vestigial (vg) and scalloped (sd) are required for wing development in Drosophila melanogaster. They present similar patterns of expression in second and third instar wing discs and similar wing mutant phenotypes. vg encodes a nuclear protein without any recognized nucleic acid-binding motif. Sd is a transcription factor homologous to the human TEF-1 factor whose promoter activity depends on cell-specific cofactors. We postulate that Vg could be a cofactor of Sd in the wing morphogenetic process and that, together, they could constitute a functional transcription complex. We investigated genetic interactions between the two genes. We show here that vg and sd co-operate in vivo in a manner dependent on the structure of the Vg protein. We ectopically expressed vg in the patch (ptc) domains. We show evidence that wing-like outgrowths induced by ectopic expression of vg are severely reduced in vg or sd mutant backgrounds. Accordingly, we demonstrate that ptc-GAL4-driven expression of vg induces both expressions of the endogenous vg and sd genes and that the two Vg and Sd proteins have to be produced together to promote wing proliferation. Furthermore, we show an interaction between the two proteins by double hybrid experiments in yeast. Our results therefore support the hypothesis that Sd and Vg directly interact in vivo to form a complex regulating the proliferation of wing tissue.

  12. Isolation, characterization, and multiplexing of novel microsatellite markers for the tropical scalloped spiny lobster (Panulirus homarus).

    Science.gov (United States)

    Delghandi, M; Goddard, S; Jerry, D R; Dao, H T; Afzal, H; Al-Jardani, S S

    2015-12-29

    Of the various spiny lobster species in the tropical and subtropical Indo-West Pacific region, the tropical scalloped spiny lobster (Panulirus homarus) supports one of the most commercially valuable fishery resources in many coastal African and Asian countries. The last decade has witnessed a serious decline in the wild populations of this species. Knowledge of the genetic basis of spiny lobster population structure is a prerequisite to achieve a sustainable fisheries management for this species. Here, we describe 13 novel polymorphic microsatellite markers developed for P. homarus, using a cross-species primer design strategy based on P. ornatus Roche 454 shot-gun generated sequencing. Microsatellite polymorphisms were assessed in 96 unrelated P. homarus individuals of a natural population, with the number of alleles per locus varying from 2 to 14, the observed and expected heterozygosity from 0.00 to 0.78 and from 0.03 to 0.79, respectively, and with only four loci (Pho-G27, Pho-G32, Pho-G36, and Pho-G58) deviating from Hardy- Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed significant departure from the null hypothesis between loci Pho-G22 - Pho-G30, and Pho-G30 - Pho-G35. The successful cross amplification of these microsatellites highlights the potential of the developed microsatellites for future population genetic research within the different Panulirus species.

  13. Potentially toxic filamentous fungi associated to the economically important Nodipecten nodosus (Linnaeus, 1758) scallop farmed in southeastern Rio de Janeiro, Brazil.

    Science.gov (United States)

    Santos, Antônia; Hauser-Davis, Rachel Ann; Santos, Manoel José Soares; De Simone, Salvatore Giovani

    2017-02-15

    Numerous countries have been confronted with infectious diseases in mariculture activities, including fungi infections, although reports in scallops are scarce. Thus, this study aimed to investigate the occurrence of filamentous fungi in Nodipecten nodosus specimens from three marine farms in Southeastern Brazil. Eight fungi genera were observed in the branchial arches, intestine and muscle tissue of the scallop specimens. These include potentially toxin-producing species, such as Aspergillus, Penicillium and Fusarium. Their presence may lead to potential public health concerns, since all sampling sites showed the presence of fungi in all scallop organs, with special concern regarding edible muscle tissue. A significant number of species was observed at one of the study areas, which could indicate a previously unknown source of contamination, since increases in fungi species richness in polluted coastal waters have been reported. This is also, to the best of our knowledge, the first report of Pestalotiopsis in shellfish. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A Genome-Wide Association Study Identifies the Genomic Region Associated with Shell Color in Yesso Scallop, Patinopecten yessoensis.

    Science.gov (United States)

    Zhao, Liang; Li, Yangping; Li, Yajuan; Yu, Jiachen; Liao, Huan; Wang, Shuyue; Lv, Jia; Liang, Jun; Huang, Xiaoting; Bao, Zhenmin

    2017-06-01

    The shell color polymorphism widely exists in economic shellfish, which not only results in a better visual perception but also shows great value as an economic trait for breeding. Small numbers of reddish-orange shell Yesso scallops, Patinopecten yessoensis, were found in cultured populations compared to the brown majority. In this study, a genome-wide association study was conducted to understand the genetic basis of shell color. Sixty-six 2b-RAD libraries with equal numbers of reddish-orange and brown shell individuals were constructed and sequenced using the Illumina HiSeq 2000 platform. A total of 322,332,684 high-quality reads were obtained, and the average sequencing depth was 18.4×. One genomic region on chromosome 11 that included 239 single-nucleotide polymorphisms (SNPs) was identified as significantly associated with shell color. After verification by high-resolution melting in another population, two SNPs were selected as specific loci for reddish-orange shell color. These two SNPs could be used to improve the selective breeding progress of true-breeding strains with complete reddish-orange scallops. In addition, within the significantly associated genomic region, candidate genes were identified using marker sequences to search the draft genome of Yesso scallop. Three genes (LDLR, FRIS, and FRIY) with known functions in carotenoid metabolism were identified. Further study using high-performance liquid chromatography proved that the relative level of carotenoids in the reddish-orange shells was 40 times higher than that in the brown shells. These results suggested that the accumulation of carotenoids contributes to the formation of reddish-orange shells.

  15. First report of Vibrio tubiashii associated with a massive larval mortality event in a commercial hatchery of scallop Argopecten purpuratus in Chile

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    Rodrigo Alejandro Rojas

    2016-09-01

    Full Text Available The VPAP30 strain was isolated as the highly predominant bacteria from an episode of massive larval mortality occurring in a commercial culture of the Chilean scallop Argopecten purpuratus. The main aims of this study were, to characterize and identify the pathogenic strain using biochemical and molecular methods to demonstrate its pathogenic activity on scallop larvae, to characterize its pathogenic properties and to describe the chronology of this pathology. The pathogenic strain was identified as Vibrio tubiashii based on its phenotypic properties and the sequence analysis of its 16S rRNA and housekeeping genes (ftsZ, gapA, gyrB, mreB, pyrH, recA, rpoA and topA. When triplicate cultures of healthy 10–day–old scallop larvae were challenged with 1×105 colony forming units (CFU mL-1 of the VPAP30 strain, percentages of larval survival of 78.87 ± 3.33%, 34.32 ± 4.94% and 0% were observed at 12, 24 and 36 h, respectively; whereas uninfected larval cultures showed survival rates of 97.4 ± 1.24% after of 48 h. Clinical symptoms exhibited by the scallop larvae infected with the VPAP30 strain include the accumulation of bacteria around the scallop larvae, velum disruption and necrosis of digestive gland. The 50% lethal dose (LD50 of VPAP30 strain at 24 and 48 h was 1.3×104 and 1.2×103 CFU mL-1, respectively. The invasive pathogenic activity of the VPAP30 strain was investigated with staining of the bacterial pathogen with 5-DTAF and analysing bacterial invasion using epifluorescence, and a complete bacterial dissemination inside the larvae at 24 h post-infection was observed. When scallop larvae were inoculated with cell-free extracellular products (ECPs of VPAP30, the larval survival rate was 59.5 ± 1.66%, significantly (P<0.001 lower than the control group (97.4 ± 1.20% whereas larvae treated with heat-treated ECPs exhibited a survival rate of 61.6 ± 1.84% after 48 h of exposure. This is the first report of the isolation of V. tubiashii

  16. [Comparison of the fungal complexes of the Japanese scallop Mizuhopecten yessoensis (Jay, 1856) from different areas of the Peter the Great Bay, Sea of Japan].

    Science.gov (United States)

    Borzykh, O G; Zvereva, L V

    2014-01-01

    Mycological investigation of the Japanese scallop Mizuhopecten yessoensis (Jay) (Bivalvia) collected in different areas of the Peter the Great Bay, Sea of Japan, was carried out. A total of 72 species of filamentous fungi belonging to 30 genera of ascomycetes, anamorphous fungi, and zygomycetes was isolated from the internal organs of the scallop. The species.diversity of mycelial fungi in the internal organs, especially of members of the generaAspergillus, Penicillium, Cladosporium, and Chaetomium, was found to increase in polluted coastal waters.

  17. Soybean oil methanolysis over scallop shell-derived CaO prepared via methanol-assisted dry nano-grinding

    OpenAIRE

    Panjaitan, Frisda R.; Yamanaka, Shinya; Kuga, Yoshikazu

    2017-01-01

    Calcium oxides with a specific surface area between 4.5 m2g-1 and 62.5 m2g-1 were obtained by calcination of scallop shells, following by methanol-assisted dry nano-grinding. Three distinct phases are formed on the surface of these catalysts during nano-grinding: calcium methoxide, calcium hydroxide, and calcium oxide. The effects of specific surface area and active surface phase composition on the catalytic activity of calcium oxide during methanolysis of soybean oil were investigated. The p...

  18. Demographic processes underlying subtle patterns of population structure in the scalloped hammerhead shark, Sphyrna lewini.

    Science.gov (United States)

    Nance, Holly A; Klimley, Peter; Galván-Magaña, Felipe; Martínez-Ortíz, Jimmy; Marko, Peter B

    2011-01-01

    Genetic diversity (θ), effective population size (N(e)), and contemporary levels of gene flow are important parameters to estimate for species of conservation concern, such as the globally endangered scalloped hammerhead shark, Sphyrna lewini. Therefore, we have reconstructed the demographic history of S. lewini across its Eastern Pacific (EP) range by applying classical and coalescent population genetic methods to a combination of 15 microsatellite loci and mtDNA control region sequences. In addition to significant population genetic structure and isolation-by-distance among seven coastal sites between central Mexico and Ecuador, the analyses revealed that all populations have experienced a bottleneck and that all current values of θ are at least an order of magnitude smaller than ancestral θ, indicating large decreases in N(e) (θ = 4N(e)μ), where μ is the mutation rate. Application of the isolation-with-migration (IM) model showed modest but significant genetic connectivity between most sampled sites (point estimates of Nm = 0.1-16.7), with divergence times (t) among all populations significantly greater than zero. Using a conservative (i.e., slow) fossil-based taxon-specific phylogenetic calibration for mtDNA mutation rates, posterior probability distributions (PPDs) for the onset of the decline in N(e) predate modern fishing in this region. The cause of decline over the last several thousand years is unknown but is highly atypical as a post-glacial demographic history. Regardless of the cause, our data and analyses suggest that S. lewini was far more abundant throughout the EP in the past than at present.

  19. Demographic processes underlying subtle patterns of population structure in the scalloped hammerhead shark, Sphyrna lewini.

    Directory of Open Access Journals (Sweden)

    Holly A Nance

    Full Text Available Genetic diversity (θ, effective population size (N(e, and contemporary levels of gene flow are important parameters to estimate for species of conservation concern, such as the globally endangered scalloped hammerhead shark, Sphyrna lewini. Therefore, we have reconstructed the demographic history of S. lewini across its Eastern Pacific (EP range by applying classical and coalescent population genetic methods to a combination of 15 microsatellite loci and mtDNA control region sequences. In addition to significant population genetic structure and isolation-by-distance among seven coastal sites between central Mexico and Ecuador, the analyses revealed that all populations have experienced a bottleneck and that all current values of θ are at least an order of magnitude smaller than ancestral θ, indicating large decreases in N(e (θ = 4N(eμ, where μ is the mutation rate. Application of the isolation-with-migration (IM model showed modest but significant genetic connectivity between most sampled sites (point estimates of Nm = 0.1-16.7, with divergence times (t among all populations significantly greater than zero. Using a conservative (i.e., slow fossil-based taxon-specific phylogenetic calibration for mtDNA mutation rates, posterior probability distributions (PPDs for the onset of the decline in N(e predate modern fishing in this region. The cause of decline over the last several thousand years is unknown but is highly atypical as a post-glacial demographic history. Regardless of the cause, our data and analyses suggest that S. lewini was far more abundant throughout the EP in the past than at present.

  20. Identification of a classical bipartite nuclear localization signal in the Drosophila TEA/ATTS protein scalloped.

    Directory of Open Access Journals (Sweden)

    Adam C Magico

    Full Text Available Drosophila melanogaster wing development has been shown to rely on the activity of a complex of two proteins, Scalloped (Sd and Vestigial (Vg. Within this complex, Sd is known to provide DNA binding though its TEA/ATTS domain, while Vg modulates this binding and provides transcriptional activation through N- and C-terminal activation domains. There is also evidence that Sd is required for the nuclear translocation of Vg. Indeed, a candidate sequence which shows consensus to the bipartite family of nuclear localization signals (NLSs has been identified within Sd previously, though it is not known if it is functional, or if additional unpredicted signals that mediate nuclear transport exist within the protein. By expressing various enhanced green fluorescent protein (eGFP tagged constructs within Drosophila S2 cells, we demonstrate that this NLS is indeed functional and necessary for the proper nuclear localization of Sd. Additionally, the region containing the NLS is critical for the wildtype function of ectopically expressed Sd, in the context of wing development. Using site-directed mutagenesis, we have identified a group of five amino acids within this NLS which is critical for its function, as well as another group of two which is of lesser importance. Together with data that suggests that this sequence mediates interactions with Importin-α3, we conclude that the identified NLS is likely a classical bipartite signal. Further dissection of Sd has also revealed that a large portion of the C-terminal domain of the protein is required its proper nuclear localization. Finally, a Leptomycin B (LB sensitive signal which appears to facilitate nuclear export is identified, raising the possibility that Sd also contains a nuclear export signal (NES.

  1. Identification of a classical bipartite nuclear localization signal in the Drosophila TEA/ATTS protein scalloped.

    Science.gov (United States)

    Magico, Adam C; Bell, John B

    2011-01-01

    Drosophila melanogaster wing development has been shown to rely on the activity of a complex of two proteins, Scalloped (Sd) and Vestigial (Vg). Within this complex, Sd is known to provide DNA binding though its TEA/ATTS domain, while Vg modulates this binding and provides transcriptional activation through N- and C-terminal activation domains. There is also evidence that Sd is required for the nuclear translocation of Vg. Indeed, a candidate sequence which shows consensus to the bipartite family of nuclear localization signals (NLSs) has been identified within Sd previously, though it is not known if it is functional, or if additional unpredicted signals that mediate nuclear transport exist within the protein. By expressing various enhanced green fluorescent protein (eGFP) tagged constructs within Drosophila S2 cells, we demonstrate that this NLS is indeed functional and necessary for the proper nuclear localization of Sd. Additionally, the region containing the NLS is critical for the wildtype function of ectopically expressed Sd, in the context of wing development. Using site-directed mutagenesis, we have identified a group of five amino acids within this NLS which is critical for its function, as well as another group of two which is of lesser importance. Together with data that suggests that this sequence mediates interactions with Importin-α3, we conclude that the identified NLS is likely a classical bipartite signal. Further dissection of Sd has also revealed that a large portion of the C-terminal domain of the protein is required its proper nuclear localization. Finally, a Leptomycin B (LB) sensitive signal which appears to facilitate nuclear export is identified, raising the possibility that Sd also contains a nuclear export signal (NES).

  2. Ability of scalloped deletion constructs to rescue sd mutant wing phenotypes in Drosophila melanogaster.

    Science.gov (United States)

    Chow, Leola; Berube, Joel; Fromont, Alice; Bell, John B

    2004-10-01

    Scalloped (SD) and Vestigial (VG) proteins physically interact to form a selector complex that activates genes involved in wing development in Drosophila melanogaster. SD belongs to a conserved family of transcription factors containing the TEA/ATTS DNA-binding motif. VG is also a nuclear protein providing the activator function for the SD VG complex. The TEA DNA-binding domain and the VG interacting domain (VID) of SD have been previously identified and described. However, they, and possibly other functional domains of SD, have not been thoroughly characterized in vivo. Herein, transgenic constructs encoding various truncations of SD were used to assess their respective ability to rescue the mutant wing phenotype of two viable sd recessive mutations (sd(ETX4) and sd(58d)). The transgenic strains produced were also tested for the ability to induce further sd expression, an ability possessed by full length SD. The functional dissection of SD confirms that specific regions are necessary for wing development and provides further information as to how the SD VG complex functions to promote wing fate. Previous experiments have shown that expression of full length SD can cause a dominant negative wing phenotype. We show that expression of constructs that delete the SD DNA-binding domain can also cause a dominant negative phenotype in a background with either of the two tester sd strains. In contrast, SD constructs that delete the VID have no effect on the wing phenotype in either tester background. Finally, a significant portion of SD at the N-terminal end appears to be dispensable with respect to normal wing development, as this construct behaves the same as full length SD in our assays.

  3. Inheritance pattern of microsatellite loci and their use for kinship analysis in the Japanese scallop Patinopecten yessoensis

    Science.gov (United States)

    Xu, Kefeng; Li, Qi

    2009-06-01

    The inheritance mode of seven microsatellite markers was investigated in Patinopecten yessoensis larvae from four controlled crosses, and the feasibility of using these markers for kinship estimation was also examined. All the seven microsatellite loci were compatible with Mendelian inheritance. Neither sex-linked barriers to transmission nor major barriers to fertilization between gametes from the parents were evident. Two of the seven loci showed the presence of null alleles in two families, suggesting the need to conduct comprehensive species-specific inheritance studies for microsatellite loci used in population genetic studies. However, even if the null allele heterozygotes were considered as homozygotes in the calculation of genetic distance, offspring from four families were all unambiguously discriminated in the neighbor-joining dendrogram. This result indicates that the microsatellite markers used may be capable of discriminating between related and unrelated scallop larvae in the absence of pedigree information, and of investigating the effective number of parents contributing to the hatchery population of the Japanese scallop.

  4. Accumulation of nine metals and one metalloid in the tropical scallop Comptopallium radula from coral reefs in New Caledonia

    Energy Technology Data Exchange (ETDEWEB)

    Metian, M. [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine Ier, MC-98000 Monaco (Monaco); Centre de Recherche sur les Ecosystemes Littoraux Anthropises, UMR 6217, CNRS-IFREMER-Universite de La Rochelle, 22 avenue Michel Crepeau, F-17042 La Rochelle Cedex 01 (France)], E-mail: mametian@gmail.com; Bustamante, P. [Centre de Recherche sur les Ecosystemes Littoraux Anthropises, UMR 6217, CNRS-IFREMER-Universite de La Rochelle, 22 avenue Michel Crepeau, F-17042 La Rochelle Cedex 01 (France)], E-mail: pbustama@univ-lr.fr; Hedouin, L. [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine Ier, MC-98000 Monaco (Monaco) and Centre de Recherche sur les Ecosystemes Littoraux Anthropises, UMR 6217, CNRS-IFREMER-Universite de La Rochelle, 22 avenue Michel Crepeau, F-17042 La Rochelle Cedex 01 (France) and IRD-Centre de Noumea, BP A5, 98848 Noumea Cedex, New Caledonia; Warnau, M. [International Atomic Energy Agency - Marine Environment Laboratories, 4 Quai Antoine Ier, MC-98000 Monaco (Monaco)], E-mail: m.warnau@iaea.org

    2008-04-15

    Uptake of waterborne Cd, Co, Mn and Zn was determined in laboratory experiments using radiotracer techniques ({sup 109}Cd, {sup 57}Co, {sup 54}Mn and {sup 65}Zn). Labelled Zn was mainly accumulated in the digestive gland (65%) and Co in kidneys (81%); Cd and Mn were similarly distributed in digestive gland and gills. In a complementary field study, Ag, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, and Zn were analysed in scallops collected at two stations showing different contamination levels. Digestive gland and kidneys displayed the highest concentrations. Ag, As, Cd, and Fe differed in soft tissues from the two stations, suggesting that Comptopallium radula could be a valuable local biomonitor species for these elements. Low Mn and Zn concentrations found in kidneys suggest that their content in calcium-phosphate concretions differs from the other pectinids. Preliminary risk considerations suggest that As would be the only element potentially leading to exposure of concern for seafood consumers. - This study investigates metal accumulation behaviour in the tropical scallop Comptopallium radula and preliminary risk assessment for consumers.

  5. A coupled biophysical model for the distribution of the great scallop Pecten maximus in the English Channel

    Science.gov (United States)

    Le Goff, Clément; Lavaud, Romain; Cugier, Philippe; Jean, Fred; Flye-Sainte-Marie, Jonathan; Foucher, Eric; Desroy, Nicolas; Fifas, Spyros; Foveau, Aurélie

    2017-03-01

    In this paper we used a modelling approach integrating both physical and biological constraints to understand the biogeographical distribution of the great scallop Pecten maximus in the English Channel during its whole life cycle. A 3D bio-hydrodynamical model (ECO-MARS3D) providing environmental conditions was coupled to (i) a population dynamics model and (ii) an individual ecophysiological model (Dynamic Energy Budget model). We performed the coupling sequentially, which underlined the respective role of biological and physical factors in defining P. maximus distribution in the English Channel. Results show that larval dispersion by hydrodynamics explains most of the scallop distribution and enlighten the main known hotspots for the population, basically corresponding to the main fishing areas. The mechanistic description of individual bioenergetics shows that food availability and temperature control growth and reproduction and explain how populations may maintain themselves in particular locations. This last coupling leads to more realistic densities and distributions of adults in the English Channel. The results of this study improves our knowledge on the stock and distribution dynamics of P. maximus, and provides grounds for useful tools to support management strategies.

  6. Accumulation of γ-aminobutyric acid by Enterococcus avium 9184 in scallop solution in a two-stage fermentation strategy.

    Science.gov (United States)

    Yang, Haoyue; Xing, Ronge; Hu, Linfeng; Liu, Song; Li, Pengcheng

    2016-07-01

    In this study, a new bacterial strain having a high ability to produce γ-aminobutyric acid (GABA) was isolated from naturally fermented scallop solution and was identified as Enterococcus avium. To the best of our knowledge, this is the first study to prove that E. avium possesses glutamate decarboxylase activity. The strain was then mutagenized with UV radiation and was designated as E. avium 9184. Scallop solution was used as the culture medium to produce GABA. A two-stage fermentation strategy was applied to accumulate GABA. In the first stage, cell growth was regulated. Optimum conditions for cell growth were pH, 6.5; temperature, 37°C; and glucose concentration, 10 g·L(-1) . This produced a maximum dry cell mass of 2.10 g·L(-1) . In the second stage, GABA formation was regulated. GABA concentration reached 3.71 g·L(-1) at 96 h pH 6.0, 37°C and initial l-monosodium glutamate concentration of 10 g·L(-1) . Thus, compared with traditional one-stage fermentation, the two-stage fermentation significantly increased GABA accumulation. These results provide preliminary data to produce GABA using E. avium and also provide a new approach to process and utilize shellfish. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  7. Novel 14-nm Scallop-Shaped FinFETs (S-FinFETs) on Bulk-Si Substrate

    Science.gov (United States)

    Xu, Weijia; Yin, Huaxiang; Ma, Xiaolong; Hong, Peizhen; Xu, Miao; Meng, Lingkuan

    2015-06-01

    In this study, novel p-type scallop-shaped fin field-effect transistors (S-FinFETs) are fabricated using an all-last high-k/metal gate (HKMG) process on bulk-silicon (Si) substrates for the first time. In combination with the structure advantage of conventional Si nanowires, the proposed S-FinFETs provide better electrostatic integrity in the channels than normal bulk-Si FinFETs or tri-gate devices with rectangular or trapezoidal fins. It is due to formation of quasi-surrounding gate electrodes on scalloping fins by a special Si etch process. The entire integration flow of the S-FinFETs is fully compatible with the mainstream all-last HKMG FinFET process, except for a modified fin etch process. The drain-induced barrier lowering and subthreshold swing of the fabricated p-type S-FinFETs with a 14-nm physical gate length are 62 mV/V and 75 mV/dec, respectively, which are much better than those of normal FinFETs with a similar process. With an improved short-channel-effect immunity in the channels due to structure modification, the novel structure provides one of possibilities to extend the FinFET scalability to sub-10-nm nodes with little additional process cost.

  8. SOME BIOLOGICAL ASPECTS OF SCALLOPED HAMMERHEAD SHARKS (Sphyrna lewini Griffith & Smith, 1834 CAUGHT FROM COASTAL FISHERIES IN THE EASTERN INDIAN OCEAN

    Directory of Open Access Journals (Sweden)

    Umi Chodrijah

    2015-12-01

    Full Text Available Indonesia has the largest chondrichthyan fishery in the world, with a reported of 105,000 and 118,000 tonnes landed in 2002 and 2003 respectively. Scalloped hammerhead shark was either targeted or by-catch from this fishery, mostly for its fins. Despite of the growing concern around the world, the availability of biological data of this species, especially in the Eastern Indian Ocean is still lacking. The objectives of this paper are to present some biological information (size composition and sex ratio of the scalloped hammerhead, from coastal fisheries in Eastern Indian Ocean. The data used for the analysis comprised of two components, i.e. survey data in 2010 (February, March, June, August, October and December and data from daily monitoring shark landing in 2013 (January to December. Substantially lower mean size, more immature sharks and more frequent of female caught over years showed that scalloped hammerhead shark in the Eastern Indian Ocean are facing intensive fishing pressure which could lead to overfishing. This could harm the sustainability of scalloped hammerhead shark resource in the long run. The relationship between clasper length and total length was positively correlated where every 5 cmTL increment on clasper length adding 51 cmTL on total length.

  9. Age, growth and maturity of the pelagic thresher Alopias pelagicus and the scalloped hammerhead Sphyrna lewini.

    Science.gov (United States)

    Drew, M; White, W T; Dharmadi; Harry, A V; Huveneers, C

    2015-01-01

    Indonesia has the greatest reported chondrichthyan catches worldwide, with c.110,000 t caught annually. The pelagic thresher (Alopias pelagicus) and scalloped hammerhead (Sphryna lewini) together comprise about 25% of the total catches of sharks landed in Indonesia. Age and growth parameters were estimated for A. pelagicus and S. lewini from growth-band counts of thin-cut vertebral sections. Alopias pelagicus (n = 158) and S. lewini (n = 157) vertebrae were collected from three Indonesian fish markets over a 5 year period. A multi-model analysis was used to estimate growth parameters for both species. The models of best fit for males and females for A. pelagicus was the three-parameter logistic (L∞ = 3169 mm LT , k = 0·2) and the two-parameter von Bertalanffy models (L∞ = 3281 mm LT , k = 0·12). Age at maturity was calculated to be 10·4 and 13·2 years for males and females, respectively, and these are the oldest estimated for this species. The samples of S. lewini were heavily biased towards females, and the model of best fit for males and females was the three-parameter Gompertz (L∞ = 2598 mm LT , k = 0·15) and the two-parameter Gompertz (L∞ = 2896 mm LT , k= 0·16). Age at maturity was calculated to be 8·9 and 13·2 years for males and females, respectively. Although numerous age and growth studies have previously been undertaken on S. lewini, few studies have been able to obtain adequate samples from all components of the population because adult females, adult males and juveniles often reside in different areas. For the first time, sex bias in this study was towards sexually mature females, which are commonly lacking in previous biological studies on S. lewini. Additionally, some of the oldest aged specimens and highest age at maturity for both species were observed in this study. Both species exhibit slow rates of growth and late age at maturity, highlighting the need for a re-assessment of the relative resilience of these two

  10. Extensive use of mesopelagic waters by a Scalloped hammerhead shark (Sphyrna lewini) in the Red Sea

    KAUST Repository

    Spät, Julia L.Y.

    2017-09-06

    Background Despite being frequently landed in fish markets along the Saudi Arabian Red Sea coast, information regarding fundamental biology of the Scalloped hammerhead shark (Sphyrna lewini) in this region is scarce. Satellite telemetry studies can generate important data on life history, describe critical habitats, and ultimately redefine management strategies for sharks. To better understand the horizontal and vertical habitat use of S. lewini in the Red Sea and to aid with potential future development of zoning and management plans for key habitats, we deployed a pop-up satellite archival transmitting tag to track a single female specimen (240 cm total length) for a tracking period of 182 days. Results The tag was physically recovered after a deployment period of 6 months, thus providing the complete archived dataset of more than one million depth and temperature records. Based on a reconstructed, most probable track, the shark travelled a circular distance of approximately 1000 km from the central Saudi Arabian Red Sea southeastward into Sudanese waters, returning to the tagging location toward the end of the tracking period. Mesopelagic excursions to depths between 650 and 971 m occurred on 174 of the 182 days of the tracking period. Intervals between such excursions were characterized by constant oscillatory diving in the upper 100 m of the water column. Conclusions This study provides evidence that mesopelagic habitats might be more commonly used by S. lewini than previously suggested. We identified deep diving behavior throughout the 24-h cycle over the entire 6-month tracking period. In addition to expected nightly vertical habitat use, the shark exhibited frequent mesopelagic excursions during daytime. Deep diving throughout the diel cycle has not been reported before and, while dive functionality remains unconfirmed, our study suggests that mesopelagic excursions may represent foraging events within and below deep scattering layers. Additional research

  11. Fusarium solani fungal infection of the lateral line canal system in captive scalloped hammerhead sharks (Sphyrna lewini) in Hawaii.

    Science.gov (United States)

    Crow, G L; Brock, J A; Kaiser, S

    1995-10-01

    Two of five scalloped hammerhead sharks (Sphyrna lewini) captured May 1987 in Hawaii (USA) developed granulomatous exudative mycotic dermatitis localized in the lateral line canal system. The lesion initially was noted in the cephalic canals, but over a period of months extended into the lateral canal. Fusarium solani and Vibrio spp. were isolated from the canal exudate of both sharks. Bacterial colonies were not observed in the canal walls or surrounding tissues. Fusarium solani infection resulted in a chronic physical and behavioral deterioration of the two sharks; one shark was euthanized in September 1988 and the other in July 1989. This is the first report of Fusarium solani infection in the lateral line canal system and the third account in hammerhead sharks.

  12. Quality and shelf life of the gonad of lion's paw scallop transported and stored whole in refrigeration

    Directory of Open Access Journals (Sweden)

    Victor Manuel Ocaño-Higuera

    2015-05-01

    Full Text Available The effect of refrigerated 48h transport and 4 days storage on the quality and shelf life of the whole lion's paw scallop Nodipecten subnodosus gonad was evaluated. Proximal composition, adenosine 5´triphosphate (ATP and related products, K-value, total volatile bases (TVB-N, trimethylamine (TMA-N, pH, fatty acid profile and microbiological analyses were quantified. Gonad holds a significant composition of essential fatty acids while levels of gonadal ATP were initially low; moreover, K-value of the gonad remained constant. With respect to TVB-N and TMA-N, only the former exceeded allowed limits. The pH level showed no significant variation during storage and, despite the high level of TVB-N, according to the TMA-N as well as microbiological analyses it was demonstrated innocuity after 4 days under the transportation and storage conditions utilized.

  13. Vestigial and scalloped in the ladybird beetle: a conserved function in wing development and a novel function in pupal ecdysis.

    Science.gov (United States)

    Ohde, T; Masumoto, M; Morita-Miwa, M; Matsuura, H; Yoshioka, H; Yaginuma, T; Niimi, T

    2009-10-01

    In Drosophila melanogaster, Vestigial (Vg) and Scalloped (Sd) form a transcription factor complex and play a crucial role in wing development. To extend our knowledge of insect wing formation, we isolated vg and sd homologues from two ladybird beetle species, Henosepilachna vigintioctopunctata and Harmonia axyridis. Although the ladybird beetle vg homologues had only low homology with D. melanogaster vg, ectopic expression of H. vigintioctopunctata vg induced wing-like tissues in antennae and legs of D. melanogaster. Subsequent larval RNA interference (RNAi) analysis in H. vigintioctopunctata demonstrated conserved functions of vg and sd in wing development, and an unexpected novel function of sd in pupal ecdysis. Furthermore, our results can be applied to the production of a flightless ladybird beetle for biological control purposes using larval RNAi.

  14. Identification of male gametogenesis expressed genes from the scallop Nodipecten subnodosus by suppressive subtraction hybridization and pyrosequencing.

    Science.gov (United States)

    Llera-Herrera, Raúl; García-Gasca, Alejandra; Abreu-Goodger, Cei; Huvet, Arnaud; Ibarra, Ana M

    2013-01-01

    Despite the great advances in sequencing technologies, genomic and transcriptomic information for marine non-model species with ecological, evolutionary, and economical interest is still scarce. In this work we aimed to identify genes expressed during spermatogenesis in the functional hermaphrodite scallop Nodipecten subnodosus (Mollusca: Bivalvia: Pectinidae), with the purpose of obtaining a panel of genes that would allow for the study of differentially transcribed genes between diploid and triploid scallops in the context of meiotic arrest and reproductive sterility. Because our aim was to isolate genes involved in meiosis and other testis maturation-related processes, we generated suppressive subtractive hybridization libraries of testis vs. inactive gonad. We obtained 352 and 177 ESTs by clone sequencing, and using pyrosequencing (454-Roche) we maximized the identified ESTs to 34,276 reads. A total of 1,153 genes from the testis library had a blastx hit and GO annotation, including genes specific for meiosis, spermatogenesis, sex-differentiation, and transposable elements. Some of the identified meiosis genes function in chromosome pairing (scp2, scp3), recombination and DNA repair (dmc1, rad51, ccnb1ip1/hei10), and meiotic checkpoints (rad1, hormad1, dtl/cdt2). Gene expression analyses in different gametogenic stages in both sexual regions of the gonad of meiosis genes confirmed that the expression was specific or increased towards the maturing testis. Spermatogenesis genes included known testis-specific ones (kelch-10, shippo1, adad1), with some of these known to be associated to sterility. Sex differentiation genes included one of the most conserved genes at the bottom of the sex-determination cascade (dmrt1). Transcript from transposable elements, reverse transcriptase, and transposases in this library evidenced that transposition is an active process during spermatogenesis in N. subnodosus. In relation to the inactive library, we identified 833

  15. Identification of male gametogenesis expressed genes from the scallop Nodipecten subnodosus by suppressive subtraction hybridization and pyrosequencing.

    Directory of Open Access Journals (Sweden)

    Raúl Llera-Herrera

    Full Text Available Despite the great advances in sequencing technologies, genomic and transcriptomic information for marine non-model species with ecological, evolutionary, and economical interest is still scarce. In this work we aimed to identify genes expressed during spermatogenesis in the functional hermaphrodite scallop Nodipecten subnodosus (Mollusca: Bivalvia: Pectinidae, with the purpose of obtaining a panel of genes that would allow for the study of differentially transcribed genes between diploid and triploid scallops in the context of meiotic arrest and reproductive sterility. Because our aim was to isolate genes involved in meiosis and other testis maturation-related processes, we generated suppressive subtractive hybridization libraries of testis vs. inactive gonad. We obtained 352 and 177 ESTs by clone sequencing, and using pyrosequencing (454-Roche we maximized the identified ESTs to 34,276 reads. A total of 1,153 genes from the testis library had a blastx hit and GO annotation, including genes specific for meiosis, spermatogenesis, sex-differentiation, and transposable elements. Some of the identified meiosis genes function in chromosome pairing (scp2, scp3, recombination and DNA repair (dmc1, rad51, ccnb1ip1/hei10, and meiotic checkpoints (rad1, hormad1, dtl/cdt2. Gene expression analyses in different gametogenic stages in both sexual regions of the gonad of meiosis genes confirmed that the expression was specific or increased towards the maturing testis. Spermatogenesis genes included known testis-specific ones (kelch-10, shippo1, adad1, with some of these known to be associated to sterility. Sex differentiation genes included one of the most conserved genes at the bottom of the sex-determination cascade (dmrt1. Transcript from transposable elements, reverse transcriptase, and transposases in this library evidenced that transposition is an active process during spermatogenesis in N. subnodosus. In relation to the inactive library, we identified

  16. Sensitivity towards elevated pCO2 in great scallop (Pecten maximus Lamarck) embryos and fed larvae

    Science.gov (United States)

    Andersen, Sissel; Grefsrud, Ellen S.; Harboe, Torstein

    2017-02-01

    The increasing amount of dissolved anthropogenic CO2 has caused a drop in pH values in the open ocean known as ocean acidification. This change in seawater carbonate chemistry has been shown to have a negative effect on a number of marine organisms. Early life stages are the most vulnerable, and especially the organisms that produce calcified structures in the phylum Mollusca. Few studies have looked at effects on scallops, and this is the first study presented including fed larvae of the great scallop (Pecten maximus) followed until day 14 post-fertilization. Fertilized eggs from unexposed parents were exposed to three levels of pCO2 using four replicate units: 465 (ambient), 768 and 1294 µatm, corresponding to pHNIST of 7.94, 7.75 (-0.19 units) and 7.54 (-0.40 units), respectively. All of the observed parameters were negatively affected by elevated pCO2: survival, larval development, shell growth and normal shell development. The latter was observed to be affected only 2 days after fertilization. Negative effects on the fed larvae at day 7 were similar to what was shown earlier for unfed P. maximus larvae. Growth rate in the group at 768 µatm seemed to decline after day 7, indicating that the ability to overcome the environmental change at moderately elevated pCO2 was lost over time. The present study shows that food availability does not decrease the sensitivity to elevated pCO2 in P. maximus larvae. Unless genetic adaptation and acclimatization counteract the negative effects of long term elevated pCO2, recruitment in populations of P. maximus will most likely be negatively affected by the projected drop of 0.06-0.32 units in pH within year 2100.

  17. Scallop protein with endogenous high taurine and glycine content prevents high-fat, high-sucrose-induced obesity and improves plasma lipid profile in male C57BL/6J mice.

    Science.gov (United States)

    Tastesen, Hanne Sørup; Keenan, Alison H; Madsen, Lise; Kristiansen, Karsten; Liaset, Bjørn

    2014-07-01

    High-protein diets induce alterations in metabolism that may prevent diet-induced obesity. However, little is known as to whether different protein sources consumed at normal levels may affect diet-induced obesity and associated co-morbidities. We fed obesity-prone male C57BL/6J mice high-fat, high-sucrose diets with protein sources of increasing endogenous taurine content, i.e., chicken, cod, crab and scallop, for 6 weeks. The energy intake was lower in crab and scallop-fed mice than in chicken and cod-fed mice, but only scallop-fed mice gained less body and fat mass. Liver mass was reduced in scallop-fed mice, but otherwise no changes in lean body mass were observed between the groups. Feed efficiency and apparent nitrogen digestibility were reduced in scallop-fed mice suggesting alterations in energy utilization and metabolism. Overnight fasted plasma triacylglyceride, non-esterified fatty acids, glycerol and hydroxy-butyrate levels were significantly reduced, indicating reduced lipid mobilization in scallop-fed mice. The plasma HDL-to-total-cholesterol ratio was higher, suggesting increased reverse cholesterol transport or cholesterol clearance in scallop-fed mice in both fasted and non-fasted states. Dietary intake of taurine and glycine correlated negatively with body mass gain and total fat mass, while intake of all other amino acids correlated positively. Furthermore taurine and glycine intake correlated positively with improved plasma lipid profile, i.e., lower levels of plasma lipids and higher HDL-to-total-cholesterol ratio. In conclusion, dietary scallop protein completely prevents high-fat, high-sucrose-induced obesity whilst maintaining lean body mass and improving the plasma lipid profile in male C57BL/6J mice.

  18. Comparison of total lipids and fatty acids from liver, heart and abdominal muscle of scalloped (Sphyrna lewini) and smooth (Sphyrna zygaena) hammerhead sharks.

    Science.gov (United States)

    Davidson, Bruce Clement; Nel, Wynand; Rais, Afsha; Namdarizandi, Vahid; Vizarra, Scott; Cliff, Geremy

    2014-01-01

    Liver, heart and abdominal muscle samples from scalloped (Sphyrna lewini) and smooth (Sphyrna zygaena) hammerhead sharks were analysed to characterise their lipid and fatty acid profiles. Samples were compared both between and within species, but there were no significant differences in total lipids for either comparison, although much greater total amounts were found in the liver samples. Within the individual fatty acids, the only significant differences were greater amounts of 22:6n-3, total n-3 polyunsaturates and total polyunsaturates in smooth, when compared to scalloped, hammerhead liver. This may reflect the more wide spread distribution of this species into cooler waters. Within both species the liver levels of the same fatty acid fractions decreased from spring to summer, which may correlate with changes in fatty acid profile to adapt to any differences in amount or species of prey consumed, or other considerations, eg. buoyancy, however there was no data to clarify this.

  19. Steam reforming of tar derived from lignin over pompom-like potassium-promoted iron-based catalysts formed on calcined scallop shell.

    Science.gov (United States)

    Guan, Guoqing; Kaewpanha, Malinee; Hao, Xiaogang; Zhu, Ai-Min; Kasai, Yutaka; Kakuta, Seiji; Kusakabe, Katsuki; Abudula, Abuliti

    2013-07-01

    In order to understand the improvement effect of potassium (K) on the catalytic activity of iron-loaded calcined scallop shell (CS) for the steam reforming tar derived from biomass, various K precursors were applied for the catalyst preparation. It is found that pompom-like iron-based particles with a mesoporous structure were easily formed on the surface of calcined scallop shell (CS) when K2CO3 was used as K precursor while no such kind of microsphere was formed when other kinds of K precursors such as KOH and KNO3 were applied. The optimum K-loading amount for the preparation of this catalyst was investigated. Based on the experimental results obtained, a mechanism for the formation of these microspheres was proposed. This pompom-like potassium-promoted iron-based catalyst showed a better catalytic activity and reusability for the steam reforming of tar derived from lignin. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. The genome-wide identification of mitogen-activated protein kinase kinase (MKK) genes in Yesso scallop Patinopecten yessoensis and their expression responses to bacteria challenges.

    Science.gov (United States)

    Zou, Jiajun; Wang, Ruijia; Li, Ruojiao; Kong, Yifan; Wang, Jing; Ning, Xianhui; Zhang, Lingling; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2015-08-01

    Mitogen-activated protein kinase kinases (MKK) are the essential components of the evolutionarily conserved MAPK signaling cascade, which regulates a variety of cellular activities and innate immune responses. Although MKK genes have been extensively studied in various vertebrate and invertebrate species, they have not been systematically characterized in bivalves. In this study, we identified and characterized five MKK genes (PyMKK1/2, PyMKK4, PyMKK5, PyMKK3/6 and PyMKK7) in the Yesso scallop (Patinopecten yessoensis). Phylogenetic and protein structural analyses were conducted to determine their identities and evolutionary relationships. To gain insights into the possible roles of MKK genes during scallop innate immune responses, quantitative real-time PCR (qRT-PCR) was used to investigate their expression profiles during different developmental stages in samples taken from healthy adult tissues and hemocytes after Micrococcus luteus and Vibrio anguillarum bacterial infections. The Yesso scallop MKKs (PyMKKs) were found to have highly conserved structural features compared to the MKK genes from other invertebrate species. Using qRT-PCR analysis, three distinct expression patterns were detected among the PyMKKs over the course of ten different developmental stages. In adult scallops, the majority of the PyMKKs were highly expressed in mantle, gill, muscle and hemocytes. The differential expression patterns of the five PyMKKs after M. luteus (Gram-positive) and V. anguillarum (Gram-negative) bacterial infections suggested their possible involvement in the innate immune response and provide the foundation and resource for the further study on innate immune response of MAPK signal pathway in mollusk. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. SOME BIOLOGICAL ASPECTS OF SCALLOPED HAMMERHEAD SHARKS (Sphyrna lewini Griffith & Smith, 1834) CAUGHT FROM COASTAL FISHERIES IN THE EASTERN INDIAN OCEAN

    OpenAIRE

    Umi Chodrijah; Bram Setyadji

    2015-01-01

    Indonesia has the largest chondrichthyan fishery in the world, with a reported of 105,000 and 118,000 tonnes landed in 2002 and 2003 respectively. Scalloped hammerhead shark was either targeted or by-catch from this fishery, mostly for its fins. Despite of the growing concern around the world, the availability of biological data of this species, especially in the Eastern Indian Ocean is still lacking. The objectives of this paper are to present some biological information (size composition an...

  2. Characterization of {sup 241}Am and {sup 134}Cs bioaccumulation in the king scallop Pecten maximus: investigation via three exposure pathways

    Energy Technology Data Exchange (ETDEWEB)

    Metian, Marc, E-mail: metian@hawaii.edu [International Atomic Energy Agency, Marine Environment Laboratories, 4, Quai Antoine Ier, MC-98000, Principality of Monaco (Monaco); Littoral Environnement et Societes (LIENSs), UMR 6250, CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, F-17042 La Rochelle Cedex 01 (France); Warnau, Michel; Teyssie, Jean-Louis [International Atomic Energy Agency, Marine Environment Laboratories, 4, Quai Antoine Ier, MC-98000, Principality of Monaco (Monaco); Bustamante, Paco, E-mail: paco.bustamante@univ-lr.fr [Littoral Environnement et Societes (LIENSs), UMR 6250, CNRS-Universite de La Rochelle, 2 rue Olympe de Gouges, F-17042 La Rochelle Cedex 01 (France)

    2011-06-15

    In order to understand the bioaccumulation of {sup 241}Am and {sup 134}Cs in scallops living in sediments, the uptake and depuration kinetics of these two elements were investigated in the king scallop Pecten maximus exposed via seawater, food, or sediment under laboratory conditions. Generally, {sup 241}Am accumulation was higher and its retention was stronger than {sup 134}Cs. This was especially obvious when considering whole animals exposed through seawater with whole-body concentration factors (CF{sub 7d}) of 62 vs. 1, absorption efficiencies (A{sub 0l}) of 78 vs. 45 for seawater and biological half-lives (T{sub b1/2l}) of 892 d vs. 22 d for {sup 241}Am and {sup 134}Cs, respectively. In contrast, following a single feeding with radiolabelled phytoplankton, the assimilation efficiency (AE) and T{sub b1/2l} of {sup 134}Cs were higher than those of {sup 241}Am (AE: 28% vs. 20%; T{sub b1/2l}: 14 d vs. 9 d). Among scallop tissues, the shells always contained the higher proportion of the total body burden of {sup 241}Am whatever the exposure pathway. In contrast, the whole soft parts presented the major fraction of whole-body burden of {sup 134}Cs, which was generally associated with muscular tissues. Our results showed that the two radionuclides have contrasting behaviors in scallops, in relation to their physico-chemical properties. - Highlights: > We determined Am and Cs uptake and depuration kinetics following seawater, food and sediment exposures. > We determined radionuclide tissue distribution after exposure and after depuration periods. > Am was mainly associated to the shell whatever the exposure pathway was. > Transfer processes occurred between soft and hard tissues for Am.

  3. Morphological alterations in cryopreserved spermatozoa of scallop Argopecten purpuratus Alteraciones morfológicas en espermatozoides criopreservados de concha de abanico Argopecten purpuratus

    OpenAIRE

    Carlos Espinoza; Martha Valdivia; Enrique Dupré

    2010-01-01

    The present work identifies and quantifies the morphological alterations of scallop Argopecten purpuratus spermatozoa caused by long-term cryopreservation. Percentages of motility, fertilization and injured spermatozoa were quantified by optic microscopy and scanned electron microscopy. These parameters were evaluated in sperm without treatment (CTR), spermatozoa incubated in cryoprotective solution but not freezed (ICS) and freezed-thawed spermatozoa (FTS). Spermatozoa of ICS treatment remai...

  4. THE USE OF REMOTE SENSING, REGRESSION QUANTILES, AND GIS APPROACHES FOR MODELING OF SCALLOP LARVAE: A Case Study in Funka Bay, Hokkaido, Japan

    Directory of Open Access Journals (Sweden)

    I Nyoman Radiarta

    2011-12-01

    Full Text Available In the development of scallop cultivation in Japan, larvae collection and propagation become an important factor. Although the monitoring program has been conducted, modeling of species distribution is becoming an important tool for understanding the effects of environmental changes and resources management. This study was conducted to construct a model for providing estimation of the scallop larvae distribution in Funka Bay, Hokkaido, Japan using the integration of remote sensing, Regression Quantile (RQ and Geographic Information System (GIS-based model. Data on scallop larvae were collected during one year spawning season from April to July 2003. Environmental parameters were extracted from multi sensor remotely sensed data (chlorophyll-a and sea surface temperature and a hydrographic chart (water depth. These parameters together with larvae data were then analyzed using RQ. Finally, spatial models were constructed within a GIS by combining the RQ models with digital map of environmental parameters. The results show that the model was best explained by using only sea surface temperature. The highest larvae densities were predicted in a relatively broad distribution along with the shallow water regions (Toyoura and Sawara to Yakumo and the deeper water areas (center of the bay. The spatial model built from the RQ provided robust estimation of the scallop larvae distributions in the study area, as confirmed by model validation using independent data. These findings could contribute on the monitoring program in this region in order to distinguish the potential areas for an effective spat collection.

  5. Risks and benefits of compost-like materials prepared by the thermal treatment of raw scallop hepatopancreas for supplying cadmium and the growth of alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Ushijima, Kensuke; Fukushima, Masami; Kanno, Shinya; Kanno, Itoko; Ohnishi, Mitsuhiro

    2016-01-01

    Scallop hepatopancreas, fishery waste, contains relatively high levels of Cd and organic nitrogen compounds, the latter of which represent a fertilizer. In this study, raw scallop hepatopancreas tissue was thermally treated with sawdust and red loam in the presence of an iron catalyst to produce compost-like materials (CLMs). Two CLM samples were prepared by varying the content of raw scallop hepatopancreas tissue: 46 wt.% for CLM-1 and 18 wt.% for CLM-2. Mixtures of control soil (CTL) and CLMs (CLM content: 10 and 25 wt.%) were examined for the growth of alfalfa (Medicago sativa L.) to evaluate the risks and benefits of using this material for fertilization. The Cd content in shoots and roots of alfalfa, that were grown in the presence of CLMs, was significantly higher than those for the plants grown in the CTL, indicating that Cd had accumulated in the plants from CLMs. The accumulation of Cd in the alfalfa roots was quite high in the case of the 25% CLM-1 sample. However, alfalfa growth was significantly promoted in the presence of 10% CLM-1. This can be attributed to the higher levels of nitrogen and humic substances, which serve as fertilizer components. Although the fertilization effect in case of CLM-1showed a potential benefit, the accumulation of Cd in alfalfa was clearly increased in the presence of both CLMs. In conclusion, the use of CLMs produced from raw scallop hepatopancreas tissue can be considered to have a desirable benefit from standpoint of its use as fertilizer, but is accompanied by a risk of the accumulation of Cd in alfalfa plants.

  6. A consensus microsatellite-based linkage map for the hermaphroditic bay scallop (Argopecten irradians and its application in size-related QTL analysis.

    Directory of Open Access Journals (Sweden)

    Hongjun Li

    Full Text Available Bay scallop (Argopecten irradians is one of the most economically important aquaculture species in China. In this study, we constructed a consensus microsatellite-based genetic linkage map with a mapping panel containing two hybrid backcross-like families involving two subspecies of bay scallop, A. i. irradians and A. i. concentricus. One hundred sixty-one microsatellite and one phenotypic (shell color markers were mapped to 16 linkage groups (LGs, which corresponds to the haploid chromosome number of bay scallop. The sex-specific map was 779.2 cM and 781.6 cM long in female and male, respectively, whereas the sex-averaged map spanned 849.3 cM. The average resolution of integrated map was 5.9 cM/locus and the estimated coverage was 81.3%. The proportion of distorted markers occurred more in the hybrid parents, suggesting that the segregation distortion was possibly resulted from heterospecific interaction between genomes of two subspecies of bay scallop. The overall female-to-male recombination rate was 1.13:1 across all linked markers in common to both parents, and considerable differences in recombination also existed among different parents in both families. Four size-related traits, including shell length (SL, shell height (SH, shell width (SW and total weight (TW were measured for quantitative trait loci (QTL analysis. Three significant and six suggestive QTL were detected on five LGs. Among the three significant QTL, two (qSW-10 and qTW-10, controlling SW and TW, respectively were mapped on the same region near marker AiAD121 on LG10 and explained 20.5% and 27.7% of the phenotypic variance, while the third (qSH-7, controlling SH was located on LG7 and accounted for 15.8% of the phenotypic variance. Six suggestive QTL were detected on four different LGs. The linkage map and size-related QTL obtained in this study may facilitate marker-assisted selection (MAS in bay scallop.

  7. Modelling larval dispersal of the king scallop ( Pecten maximus) in the English Channel: examples from the bay of Saint-Brieuc and the bay of Seine

    Science.gov (United States)

    Nicolle, Amandine; Dumas, Franck; Foveau, Aurélie; Foucher, Eric; Thiébaut, Eric

    2013-06-01

    The king scallop ( Pecten maximus) is one of the most important benthic species of the English Channel as it constitutes the first fishery in terms of landings in this area. To support strategies of spatial fishery management, we develop a high-resolution biophysical model to study scallop dispersal in two bays along the French coasts of the English Channel (i.e. the bay of Saint-Brieuc and the bay of Seine) and to quantify the relative roles of local hydrodynamic processes, temperature-dependent planktonic larval duration (PLD) and active swimming behaviour (SB). The two bays are chosen for three reasons: (1) the distribution of the scallop stocks in these areas is well known from annual scallop stock surveys, (2) these two bays harbour important fisheries and (3) scallops in these two areas present some differences in terms of reproductive cycle and spawning duration. The English Channel currents and temperature are simulated for 10 years (2000-2010) with the MARS-3D code and then used by the Lagrangian module of MARS-3D to model the transport. Results were analysed in terms of larval distribution at settlement and connectivity rates. While larval transport in the two bays depended both on the tidal residual circulation and the wind-induced currents, the relative role of these two hydrodynamic processes varied among bays. In the bay of Saint-Brieuc, the main patterns of larval dispersal were due to tides, the wind being only a source of variability in the extent of larval patch and the local retention rate. Conversely, in the bay of Seine, wind-induced currents altered both the direction and the extent of larval transport. The main effect of a variable PLD in relation to the thermal history of each larva was to reduce the spread of dispersal and consequently increase the local retention by about 10 % on average. Although swimming behaviour could influence larval dispersal during the first days of the PLD when larvae are mainly located in surface waters, it has a

  8. Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834), from the southern Brazilian coast.

    Science.gov (United States)

    Kotas, J E; Mastrochirico, V; Petrere Junior, M

    2011-08-01

    Age and growth studies for the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) caught along the southern Brazilian coast, were based on ring measurements of vertebrae sections of 115 males, 116 females and 14 unknown sexed sharks between 48 and 344 cm total length (TL). The von Bertalanffy growth models were best fit using back-calculated data. The growth parameters obtained for males, were L∞ = 266 cm; K = 0.05/year; L0 = 47 cm. For females, L∞ = 300 cm; K = 0.05/year; L0 = 51 cm. An adult female reached 217 cm TL and was 31.5 years old. On the other hand, an adult male was 29.5 years old and measured 234 cm TL. Longevity estimate for males and females was 55 years. Therefore, S. lewini is a long-lived fish. Ageing precision, based on the IAPE index, was 5.6%. Marginal Increment analysis based on MIR index from hammerheads smaller than 105 cm, compared with the percentual of opaque and hyaline bands found per month ageing whole vertebrae, showed an annual ring formation, i.e., in winter.

  9. Juvenile king scallop, Pecten maximus, is potentially tolerant to low levels of ocean acidification when food is unrestricted.

    Directory of Open Access Journals (Sweden)

    Matthew Burton Sanders

    Full Text Available The decline in ocean water pH and changes in carbonate saturation states through anthropogenically mediated increases in atmospheric CO2 levels may pose a hazard to marine organisms. This may be particularly acute for those species reliant on calcareous structures like shells and exoskeletons. This is of particular concern in the case of valuable commercially exploited species such as the king scallop, Pecten maximus. In this study we investigated the effects on oxygen consumption, clearance rates and cellular turnover in juvenile P. maximus following 3 months laboratory exposure to four pCO2 treatments (290, 380, 750 and 1140 µatm. None of the exposure levels were found to have significant effect on the clearance rates, respiration rates, condition index or cellular turnover (RNA: DNA of individuals. While it is clear that some life stages of marine bivalves appear susceptible to future levels of ocean acidification, particularly under food limiting conditions, the results from this study suggest that where food is in abundance, bivalves like juvenile P. maximus may display a tolerance to limited changes in seawater chemistry.

  10. High-power free-electron laser amplifier using a scalloped electron beam and a two-stage wiggler

    Directory of Open Access Journals (Sweden)

    D. C. Nguyen

    2006-05-01

    Full Text Available High-power free-electron laser (FEL amplifiers present many practical design and construction problems. One such problem is possible damage to any optical beam control elements beyond the wiggler. The ability to increase the optical beam’s divergence angle after the wiggler, thereby reducing the intensity on the first optical element, is important to minimize such damage. One proposal to accomplish this optical beam spreading is to pinch the electron beam thereby focusing the radiation as well. In this paper, we analyze an approach that relies on the natural betatron motion to pinch the electron beam near the end of the wiggler. We also consider a step-tapered, two-stage wiggler to enhance the efficiency. The combination of a pinched electron beam and step-taper wiggler leads to additional optical guiding of the optical beam. This novel configuration is studied in simulation using the MEDUSA code. For a representative set of beam and wiggler parameters, we discuss (i the effect of the scalloped beam on the interaction in the FEL and on the focusing and propagation of the radiation, and (ii the efficiency enhancement in the two-stage wiggler.

  11. Identification and expression analysis of cDNA encoding chitinase-like protein (CLP) gene in Japanese scallop Mizuhopecten yessoensis.

    Science.gov (United States)

    Gao, L; Xu, G J; Su, H; Gao, X G; Li, Y F; Bao, X B; Liu, W D; He, C B

    2014-12-18

    Chitinase-like proteins (CLP) are important members of the glycoside hydrolase family 18 (GH18) and are involved in growth control and remodeling processes. In this study, a CLP transcript was isolated and sequenced from the Japanese scallop (Mizuhopecten yessoensis) after screening expressed sequence tags. The full-length complementary DNA of M. yessoensis CLP (My-Clp1) was 1555 bp in length, consisting of a 75-bp 5'-untranslated region (UTR), a 160-bp 3'-UTR, and a 1320-bp open reading frame bearing characteristics of the GH18 family. The My-Clp1 protein was well conserved, with similar domain structures and architecture across species (e.g., from mollusks to mammals). Expression analysis in healthy tissues and across developmental stages revealed a strong preference for expression; My-Clp1 was abundantly expressed in the mantle and throughout metamorphosis, which suggests the involvement of My-Clp1 in the synthesis of extracellular components, and tissue degeneration and remodeling. My-Clp1 expression was induced after infection with a bacterial pathogen, Vibrio anguillarum, suggesting its involvement in immunity against this intracellular pathogen.

  12. Production of L-lactic Acid from Biomass Wastes Using Scallop Crude Enzymes and Novel Lactic Acid Bacterium

    Science.gov (United States)

    Yanagisawa, Mitsunori; Nakamura, Kanami; Nakasaki, Kiyohiko

    In the present study, biomass waste raw materials including paper mill sludge, bamboo, sea lettuce, and shochu residue (from a distiller) and crude enzymes derived from inedible and discarded scallop parts were used to produce L-lactic acid for the raw material of biodegradable plastic poly-lactic acid. The activities of cellulase and amylase in the crude enzymes were 22 and 170units/L, respectively, and L-lactic acid was produced from every of the above mentioned biomass wastes, by the method of liquid-state simultaneous saccharification and fermentation (SSF) . The L-lactic acid concentrations produced from sea lettuce and shochu residue, which contain high concentration of starch were 3.6 and 9.3g/L, respectively, and corresponded to greater than 25% of the conversion of glucans contained in these biomass wastes. Furthermore, using the solid state SSF method, concentrations as high as 13g/L of L-lactic acid were obtained from sea lettuce and 26g/L were obtained from shochu residue.

  13. Cell cycle genes regulate vestigial and scalloped to ensure normal proliferation in the wing disc of Drosophila melanogaster.

    Science.gov (United States)

    Legent, Kevin; Dutriaux, Annie; Delanoue, Rénald; Silber, Joël

    2006-08-01

    In Drosophila, the Vestigial-Scalloped (VG-SD) dimeric transcription factor is required for wing cell identity and proliferation. Previous results have shown that VG-SD controls expression of the cell cycle positive regulator dE2F1 during wing development. Since wing disc growth is a homeostatic process, we investigated the possibility that genes involved in cell cycle progression regulate vg and sd expression in feedback loops. We focused our experiments on two major regulators of cell cycle progression: dE2F1 and the antagonist dacapo (dap). Our results reinforce the idea that VG/SD stoichiometry is critical for correct development and that an excess in SD over VG disrupts wing growth. We reveal that transcriptional activity of VG-SD and the VG/SD ratio are both modulated by down-expression of cell cycle genes. We also detected a dap-induced sd up-regulation that disrupts wing growth. Moreover, we observed a rescue of a vg hypomorphic mutant phenotype by dE2F1 that is concomitant with vg and sd induction. This regulation of the VG-SD activity by dE2F1 is dependent on the vg genetic background. Our results support the hypothesis that cell cycle genes fine-tune wing growth and cell proliferation, in part, through control of the VG/SD stoichiometry and activity. This points to a homeostatic feedback regulation between proliferation regulators and the VG-SD wing selector.

  14. Comparative analysis of the reproductive strategy of lion's paw scallop Nodipecten subnodosus in Baja California Sur, Mexico

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    Marco A Angel-Dapa

    2015-07-01

    Full Text Available The reproductive strategy of lion's paw scallop Nodipecten subnodosus was evaluated in a culturing system in Bahía Tortugas, Baja California Sur, Mexico during an annual cycle, comparing its response with data previously reported at other localities. High frequencies of ripe gonads throughout the year indicate that reproduction was continuous, with two main ripening/spawning events: July-September and December-March. A continuous breeding is also reported for the species in Bahía Magdalena, Bahía Juncalito, and Bahía de Los Angeles. These eutrophic areas are Biological Active Centers where gametogenesis appears to be regulated by the energy taken from recently ingested food following an opportunistic strategy. However, the digestive gland index decreased and the muscle indices increased during one of the breeding peaks, suggesting that some stored reserves are also used to sustain gametogenesis (conservative strategy partially. High incidences of atretic oocytes are likely associated with atypical daily variations in water temperature from May through September (12 to 33°C, or with stressful conditions in the culturing system in summer. Despite this, the culturing system set in Bahía Tortugas appears beneficial for a continuous reproduction of N. subnodosus.

  15. Molecular characterization of two ferritins of the scallop Argopecten purpuratus and gene expressions in association with early development, immune response and growth rate.

    Science.gov (United States)

    Coba de la Peña, Teodoro; Cárcamo, Claudia B; Díaz, María I; Brokordt, Katherina B; Winkler, Federico M

    2016-08-01

    Ferritin is involved in several iron homoeostasis processes in molluscs. We characterized two ferritin homologues and their expression patterns in association with early development, growth rate and immune response in the scallop Argopecten purpuratus, a species of economic importance for Chile and Peru. Two ferritin subunits (Apfer1 and Apfer2) were cloned. Apfer1 cDNA is a 792bp clone containing a 516bp open reading frame (ORF) that corresponds to a novel ferritin subunit in A. purpuratus. Apfer2 cDNA is a 681bp clone containing a 522bp ORF that corresponds to a previously sequenced EST. A putative iron responsive element (IRE) was identified in the 5'-untranslated region of both genes. The deduced protein sequences of both cDNAs possessed the motifs and domains characteristic of functional ferritin subunits. Both genes showed differential expression patterns at tissue-specific and early development stage levels. Apfer1 expression level increased 40-fold along larval developmental stages, decreasing markedly after larval settlement. Apfer1 expression in mantle tissue was 2.8-fold higher in fast-growing than in slow-growing scallops. Apfer1 increased 8-fold in haemocytes 24h post-challenge with the bacterium Vibrio splendidus. Apfer2 expression did not differ between fast- and slow-growing scallops or in response to bacterial challenge. These results suggest that Apfer1 and Apfer2 may be involved in iron storage, larval development and shell formation. Apfer1 expression may additionally be involved in immune response against bacterial infections and also in growth; and thus would be a potential marker for immune capacity and for fast growth in A. purpuratus. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Molecular Cloning, Characterization, and Expression of a Catalase Gene in the Japanese Scallop Mizuhopecten yessoensis Induced in the Presence of Cadmium

    Science.gov (United States)

    Gao, Jialong; Ishizaki, Shoichiro; Nagashima, Yuji

    2016-03-01

    Cadmium (Cd) is known to influence the oxidative status of marine organisms and can induce the formation of reactive oxygen species (ROS). Catalase (CAT) is one of the important enzymes involved in scavenging high levels of ROS. In present study, we cloned CAT cDNA and investigated the response of this enzyme at the transcriptional level in the Japanese scallop Mizuhopecten yessoensis exposed to Cd. The full-length CAT cDNA (MyCAT) of 1,870 nucleotides including a 57 bp 5'-UTR, a coding sequence of 1,500 bp and a 313 bp 3'-UTR were identified from the scallop. The deduced amino acid sequence of MyCAT corresponds to 499 amino acids with predicted molecular weight of 56.48 kDa and contains highly conserved motifs of the proximal heme-binding site RLFSYSTH, proximal active signature FNRERIPERVVHAKGGG and three catalytic amino acid residues His72, Asn145, and Tyr355. Its significant homology to CATs from multiple alignments revealed that MyCAT had a high identity with CATs from other mollusks. CAT mRNA expression analysis revealed that expression level was highest in the digestive gland ( p < 0.01) but weak in muscle. Following exposure to 200 and 400 µg/l of Cd, a high amount of Cd was found to have accumulated in the digestive gland and CAT mRNA expression had significantly increased in this organ among 7-day exposed scallops ( p < 0.001). The result demonstrated that antioxidant enzymes such as CAT play important roles in counteracting Cd stress in M. yessoensis.

  17. Seasonal Variations Preserved in an Extinct Neogene Scallop, Chesapecten, from Florida to Delaware, USA and its Implications for Paleobiogeography

    Science.gov (United States)

    Goewert, A. E.; Surge, D.

    2007-12-01

    High-resolution records of climate variability on deep-time scales are needed to advance our understanding of the impact of a warming climate on seasonality and ecological change along a latitudinal gradient. The Middle Pliocene Warm Interval (MPWI: 3.2-2.8 Ma) provides insight into a globally warmer world, in which, relative to today, continental and oceanic configurations and atmospheric CO2 levels were similar; sea and continental ice were reduced; and interiors of continents were arid. Accretionary hard parts of marine organisms serve as physical (growth lines and increments) and chemical (87Sr/86Sr, δ18 O and δ13C) archives of life history, ecology, and environmental conditions during the life of the animal. Our goal was to examine variations in seasonality across latitudinal (~27° to37°N) and biogeographic (tropical to cold-­temperate) gradients of the Middle Atlantic Coastal Plain (MACP) during two intervals of warming: the Middle Miocene Climate Optimum (MMCO: 17-­15 Ma) and the Middle Pliocene Warm Interval (MPWI: 3.2-2.8 Ma). We analyzed variations in annual shell growth and isotope ratios (87Sr/86Sr, δ18O and δ13C) of 12 Chesapecten shells from the extremes of their biogeographic range (tropical to warm- temperate) (MMCO: Florida and Delaware; and MPWI: Florida and Virginia). Today, Florida is warm-temperate, and Delaware and Virginia are cold-temperate. Chesapecten are an extinct genus of scallop commonly preserved in MAPC deposits. They inhabited subtidal marine environments during the Miocene and Pliocene. We used 87Sr/86Sr ratios to tightly refine the timing and modeled age of the MMCO and MPWI. Modeled ages across Chesapecten's biogeographic extremes include: Florida (MMCO) 15.5 to 14.1±0.6 Ma; Delaware (MMCO) 18.0 to 17.5±0.4 Ma; Florida (MPWI) 3.75 to 2.05±0.9 Ma; and Virginia (MPWI) 2.45 to 1.65±0.4 Ma. We estimated seasonal temperature from the δ18O time series assuming interglacial δ18OSEAWATER values of -0.05‰ and -0.35‰ for

  18. Feeding strategy of the night shark (Carcharhinus signatus and scalloped hammerhead shark (Sphyrna lewini near seamounts off northeastern Brazil

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    Teodoro Vaske Júnior

    2009-06-01

    Full Text Available A total of 425 stomachs of night shark (Carcharhinus signatus, and 98 stomachs of scalloped hammerhead shark (Sphyrna lewini, from longline and surface gillneters near seamounts off northeastern Brazil, were analysed between 1992 and 1999. Both predators prey upon reef and benthopelagic fishes, migrant cephalopods and deep water crustaceans, showing similar feeding niches (Schoener Index T=0.75. The great prey richness of the diets may reflect the fact that the marine food web for these species is very extensive in this region. Due to the concentration for feeding of both predators in the seamounts, intense fisheries should be monitored to avoid localised depletions.Um total de 425 estômagos de tubarão-toninha (Carcharhinus signatus e 98 estômagos de tubarão-martelo-entalhado (Sphyrna lewini, oriundos da pesca de espinhel e pesca com rede de emalhe nas adjacências dos bancos oceânicos do nordeste do Brasil, foi analisado entre 1992 e 1999. Ambas as espécies predam sobre peixes bento-pelágicos e recifais, cefalópodes migradores, e crustáceos de águas profundas, apresentando nichos alimentares similares (Índice de Schoener T=0.75. A alta riqueza de presas nas dietas deve ser um reflexo de que as teias alimentares para estas espécies são consideravelmente longas nessa região. Devido à concentração alimentar de ambos predadores nos bancos oceânicos, a pescaria intensa deve ser monitorada para evitar depleções locais.

  19. Global phylogeography with mixed-marker analysis reveals male-mediated dispersal in the endangered scalloped hammerhead shark (Sphyrna lewini).

    Science.gov (United States)

    Daly-Engel, Toby S; Seraphin, Kanesa D; Holland, Kim N; Coffey, John P; Nance, Holly A; Toonen, Robert J; Bowen, Brian W

    2012-01-01

    The scalloped hammerhead shark, Sphyrna lewini, is a large endangered predator with a circumglobal distribution, observed in the open ocean but linked ontogenetically to coastal embayments for parturition and juvenile development. A previous survey of maternal (mtDNA) markers demonstrated strong genetic partitioning overall (global Φ(ST) = 0.749) and significant population separations across oceans and between discontinuous continental coastlines. We surveyed the same global range with increased sample coverage (N = 403) and 13 microsatellite loci to assess the male contribution to dispersal and population structure. Biparentally inherited microsatellites reveal low or absent genetic structure across ocean basins and global genetic differentiation (F(ST) = 0.035) over an order of magnitude lower than the corresponding measures for maternal mtDNA lineages (Φ(ST) = 0.749). Nuclear allelic richness and heterozygosity are high throughout the Indo-Pacific, while genetic structure is low. In contrast, allelic diversity is low while population structure is higher for populations at the ends of the range in the West Atlantic and East Pacific. These data are consistent with the proposed Indo-Pacific center of origin for S. lewini, and indicate that females are philopatric or adhere to coastal habitats while males facilitate gene flow across oceanic expanses. This study includes the largest sampling effort and the most molecular loci ever used to survey the complete range of a large oceanic predator, and findings emphasize the importance of incorporating mixed-marker analysis into stock assessments of threatened and endangered shark species.

  20. Early exposure of bay scallops (Argopecten irradians) to high CO₂ causes a decrease in larval shell growth.

    Science.gov (United States)

    White, Meredith M; McCorkle, Daniel C; Mullineaux, Lauren S; Cohen, Anne L

    2013-01-01

    Ocean acidification, characterized by elevated pCO₂ and the associated decreases in seawater pH and calcium carbonate saturation state (Ω), has a variable impact on the growth and survival of marine invertebrates. Larval stages are thought to be particularly vulnerable to environmental stressors, and negative impacts of ocean acidification have been seen on fertilization as well as on embryonic, larval, and juvenile development and growth of bivalve molluscs. We investigated the effects of high CO₂ exposure (resulting in pH = 7.39, Ω(ar) = 0.74) on the larvae of the bay scallop Argopecten irradians from 12 h to 7 d old, including a switch from high CO₂ to ambient CO₂ conditions (pH = 7.93, Ω(ar) = 2.26) after 3 d, to assess the possibility of persistent effects of early exposure. The survival of larvae in the high CO₂ treatment was consistently lower than the survival of larvae in ambient conditions, and was already significantly lower at 1 d. Likewise, the shell length of larvae in the high CO₂ treatment was significantly smaller than larvae in the ambient conditions throughout the experiment and by 7 d, was reduced by 11.5%. This study also demonstrates that the size effects of short-term exposure to high CO₂ are still detectable after 7 d of larval development; the shells of larvae exposed to high CO₂ for the first 3 d of development and subsequently exposed to ambientCO₂ were not significantly different in size at 3 and 7 d than the shells of larvae exposed to high CO₂ throughout the experiment.

  1. Early exposure of bay scallops (Argopecten irradians to high CO₂ causes a decrease in larval shell growth.

    Directory of Open Access Journals (Sweden)

    Meredith M White

    Full Text Available Ocean acidification, characterized by elevated pCO₂ and the associated decreases in seawater pH and calcium carbonate saturation state (Ω, has a variable impact on the growth and survival of marine invertebrates. Larval stages are thought to be particularly vulnerable to environmental stressors, and negative impacts of ocean acidification have been seen on fertilization as well as on embryonic, larval, and juvenile development and growth of bivalve molluscs. We investigated the effects of high CO₂ exposure (resulting in pH = 7.39, Ω(ar = 0.74 on the larvae of the bay scallop Argopecten irradians from 12 h to 7 d old, including a switch from high CO₂ to ambient CO₂ conditions (pH = 7.93, Ω(ar = 2.26 after 3 d, to assess the possibility of persistent effects of early exposure. The survival of larvae in the high CO₂ treatment was consistently lower than the survival of larvae in ambient conditions, and was already significantly lower at 1 d. Likewise, the shell length of larvae in the high CO₂ treatment was significantly smaller than larvae in the ambient conditions throughout the experiment and by 7 d, was reduced by 11.5%. This study also demonstrates that the size effects of short-term exposure to high CO₂ are still detectable after 7 d of larval development; the shells of larvae exposed to high CO₂ for the first 3 d of development and subsequently exposed to ambientCO₂ were not significantly different in size at 3 and 7 d than the shells of larvae exposed to high CO₂ throughout the experiment.

  2. Global phylogeography with mixed-marker analysis reveals male-mediated dispersal in the endangered scalloped hammerhead shark (Sphyrna lewini.

    Directory of Open Access Journals (Sweden)

    Toby S Daly-Engel

    Full Text Available The scalloped hammerhead shark, Sphyrna lewini, is a large endangered predator with a circumglobal distribution, observed in the open ocean but linked ontogenetically to coastal embayments for parturition and juvenile development. A previous survey of maternal (mtDNA markers demonstrated strong genetic partitioning overall (global Φ(ST = 0.749 and significant population separations across oceans and between discontinuous continental coastlines.We surveyed the same global range with increased sample coverage (N = 403 and 13 microsatellite loci to assess the male contribution to dispersal and population structure. Biparentally inherited microsatellites reveal low or absent genetic structure across ocean basins and global genetic differentiation (F(ST = 0.035 over an order of magnitude lower than the corresponding measures for maternal mtDNA lineages (Φ(ST = 0.749. Nuclear allelic richness and heterozygosity are high throughout the Indo-Pacific, while genetic structure is low. In contrast, allelic diversity is low while population structure is higher for populations at the ends of the range in the West Atlantic and East Pacific.These data are consistent with the proposed Indo-Pacific center of origin for S. lewini, and indicate that females are philopatric or adhere to coastal habitats while males facilitate gene flow across oceanic expanses. This study includes the largest sampling effort and the most molecular loci ever used to survey the complete range of a large oceanic predator, and findings emphasize the importance of incorporating mixed-marker analysis into stock assessments of threatened and endangered shark species.

  3. Seasonal variations of phytoplankton assemblages and its relation to environmental variables in a scallop culture sea area of Bohai Bay, China.

    Science.gov (United States)

    Chen, Yang-Hang; Gao, Ya-Hui; Chen, Chang-Ping; Liang, Jun-Rong; Sun, Lin; Zhen, Yu; Qiao, Ling

    2016-12-15

    Seasonal variations of phytoplankton assemblages were examined in a scallop culture sea area of Bohai Bay (China) with regard to some major physical and chemical variables. Samples were collected at three stations from July 2011 to September 2013. A total of 134 species belong to 4 phyla were identified, of which 104 were diatoms, 27 were dinoflagellates, 1 was euglenophyte and 2 were chrysophytes. The cells abundance in autumn (55.44×103cells/L) was higher than that in summer (6.99×103cells/L), spring (3.46×103cells/L) and winter (2.69×103cells/L). The Shannon-Wiener diversity index was higher in summer (3.06), followed by spring (3.02) and winter (2.91), and low in autumn (1.40). Results of canonical correspondence analysis showed that phosphate, salinity, temperature, silicate and DIN/SiO2 ratio were the most important environmental factors influencing the variation of phytoplankton community structure. It is suggested that eutrophication resulted from scallop culture would cause a potential red tide risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Yield potential and fruit quality of scallop squash (Cucurbita pepo L. var. patissonina Greb. f. radiata Nois. cultivars grown for processing

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    Eugeniusz Kołota

    2015-10-01

    Full Text Available Scallop squash fruits may be harvested at different stages of development. Small size fruits, intended both for the fresh market and the food industry, have the highest biological value. This study was conducted to determine the yield potential of scallop squash cultivars (‘Polo F1’, ‘Disco’, ‘Gagat’, ‘Okra’, ‘Sunny Delight F1’ grown on mulched (black polyethylene foil or black agrotextile or unmulched soil, and harvested when fruits reached a diameter of 3–6 cm. Based on 3-year average data, the highest marketable and early yield was produced by ‘Sunny Delight F1’. This cultivar is also appreciated by consumers for its yellow colored skin of fruits. Another advantage of this cultivar was its high nutritional value expressed by the highest content of dry matter, vitamin C, polyphenols and minerals (K, P, Ca, Mg, with limited tendency to nitrate accumulation. Among the other cultivars tested, ‘Okra’ showed high yield potential, ‘Gagat’ was a rich source of carotenoids, and ‘Disco’ – polyphenols. Black polyethylene foil and black agrotextile appeared to be equally effective mulching materials. The benefit from the application of mulch was a significant increase in yield without any change in the chemical composition of the fruit.

  5. Observations of sea ice interannual variations and spring bloom occurrences at the Japanese scallop farming area in the Okhotsk Sea using satellite imageries

    Science.gov (United States)

    Mustapha, Muzzneena Ahmad; Saitoh, Sei-Ichi

    2008-05-01

    The dynamics of ice formation and phytoplankton bloom development in the coastal region of the Okhotsk Sea, Hokkaido, where the Japanese scallop, Mizuhopecten yessoensis, are cultured were investigated using seven years (1998-2004) satellite data from the Special Sensor Microwave/Imager (SSM/I) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS). The interannual variability of sea ice cover and timing of spring bloom occurrences were analyzed. Longer ice cover in 1999, 2001 and 2003 with the presence of ice until early April and shortened ice cover in 1998, 2000, 2002 and 2004 with the occurrence of ice until early March were recognized at this area. Variability in the timing of sea ice retreat and development of spring blooms at the scallop areas were observed. Progression of a single ice edge bloom showed higher Chl- a concentration compared to development of an initial ice edge bloom followed by a later open water bloom. Higher concentration of phytoplankton biomass was observed in the initial bloom when sea ice melting is delayed compared to when the sea ice leaves earlier. Wind events were also observed to affect the occurrences of spring bloom.

  6. Mixed effects of elevated pCO2 on fertilisation, larval and juvenile development and adult responses in the mobile subtidal scallop Mimachlamys asperrima (Lamarck, 1819).

    Science.gov (United States)

    Scanes, Elliot; Parker, Laura M; O'Connor, Wayne A; Ross, Pauline M

    2014-01-01

    Ocean acidification is predicted to have severe consequences for calcifying marine organisms especially molluscs. Recent studies, however, have found that molluscs in marine environments with naturally elevated or fluctuating CO2 or with an active, high metabolic rate lifestyle may have a capacity to acclimate and be resilient to exposures of elevated environmental pCO2. The aim of this study was to determine the effects of near future concentrations of elevated pCO2 on the larval and adult stages of the mobile doughboy scallop, Mimachlamys asperrima from a subtidal and stable physio-chemical environment. It was found that fertilisation and the shell length of early larval stages of M. asperrima decreased as pCO2 increased, however, there were less pronounced effects of elevated pCO2 on the shell length of later larval stages, with high pCO2 enhancing growth in some instances. Byssal attachment and condition index of adult M. asperrima decreased with elevated pCO2, while in contrast there was no effect on standard metabolic rate or pHe. The responses of larval and adult M. asperrima to elevated pCO2 measured in this study were more moderate than responses previously reported for intertidal oysters and mussels. Even this more moderate set of responses are still likely to reduce the abundance of M. asperrima and potentially other scallop species in the world's oceans at predicted future pCO2 levels.

  7. Effect of increased pCO2 level on early shell development in great scallop (Pecten maximus Lamarck larvae

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    S. Andersen

    2013-10-01

    Full Text Available As a result of high anthropogenic CO2 emissions, the concentration of CO2 in the oceans has increased, causing a decrease in pH, known as ocean acidification (OA. Numerous studies have shown negative effects on marine invertebrates, and also that the early life stages are the most sensitive to OA. We studied the effects of OA on embryos and unfed larvae of the great scallop (Pecten maximus Lamarck, at pCO2 levels of 469 (ambient, 807, 1164, and 1599 μatm until seven days after fertilization. To our knowledge, this is the first study on OA effects on larvae of this species. A drop in pCO2 level the first 12 h was observed in the elevated pCO2 groups due to a discontinuation in water flow to avoid escape of embryos. When the flow was restarted, pCO2 level stabilized and was significantly different between all groups. OA affected both survival and shell growth negatively after seven days. Survival was reduced from 45% in the ambient group to 12% in the highest pCO2 group. Shell length and height were reduced by 8 and 15%, respectively, when pCO2 increased from ambient to 1599 μatm. Development of normal hinges was negatively affected by elevated pCO2 levels in both trochophore larvae after two days and veliger larvae after seven days. After seven days, deformities in the shell hinge were more connected to elevated pCO2 levels than deformities in the shell edge. Embryos stained with calcein showed fluorescence in the newly formed shell area, indicating calcification of the shell at the early trochophore stage between one and two days after fertilization. Our results show that P. maximus embryos and early larvae may be negatively affected by elevated pCO2 levels within the range of what is projected towards year 2250, although the initial drop in pCO2 level may have overestimated the effect of the highest pCO2 levels. Future work should focus on long-term effects on this species from hatching, throughout the larval stages, and further into the

  8. Effect of increased pCO2 level on early shell development in great scallop (Pecten maximus Lamarck) larvae

    Science.gov (United States)

    Andersen, S.; Grefsrud, E. S.; Harboe, T.

    2013-10-01

    As a result of high anthropogenic CO2 emissions, the concentration of CO2 in the oceans has increased, causing a decrease in pH, known as ocean acidification (OA). Numerous studies have shown negative effects on marine invertebrates, and also that the early life stages are the most sensitive to OA. We studied the effects of OA on embryos and unfed larvae of the great scallop (Pecten maximus Lamarck), at pCO2 levels of 469 (ambient), 807, 1164, and 1599 μatm until seven days after fertilization. To our knowledge, this is the first study on OA effects on larvae of this species. A drop in pCO2 level the first 12 h was observed in the elevated pCO2 groups due to a discontinuation in water flow to avoid escape of embryos. When the flow was restarted, pCO2 level stabilized and was significantly different between all groups. OA affected both survival and shell growth negatively after seven days. Survival was reduced from 45% in the ambient group to 12% in the highest pCO2 group. Shell length and height were reduced by 8 and 15%, respectively, when pCO2 increased from ambient to 1599 μatm. Development of normal hinges was negatively affected by elevated pCO2 levels in both trochophore larvae after two days and veliger larvae after seven days. After seven days, deformities in the shell hinge were more connected to elevated pCO2 levels than deformities in the shell edge. Embryos stained with calcein showed fluorescence in the newly formed shell area, indicating calcification of the shell at the early trochophore stage between one and two days after fertilization. Our results show that P. maximus embryos and early larvae may be negatively affected by elevated pCO2 levels within the range of what is projected towards year 2250, although the initial drop in pCO2 level may have overestimated the effect of the highest pCO2 levels. Future work should focus on long-term effects on this species from hatching, throughout the larval stages, and further into the juvenile and adult

  9. Biomineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification, supplement to: Ramajo, L; Marba, Núria; Prado, Luis; Peron, Sophie; Lardies, Marco A; Rodriguez-Navarro, Alejandro; Vargas, C A; Lagos, Nelson A; Duarte, Carlos M (2016): Biomineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification. Global Change Biology, 22(6), 2025-2037

    KAUST Repository

    Ramajo, L

    2016-01-01

    Future ocean acidification (OA) will affect physiological traits of marine species, with calcifying species being particularly vulnerable. As OA entails high energy demands, particularly during the rapid juvenile growth phase, food supply may play a key role in the response of marine organisms to OA. We experimentally evaluated the role of food supply in modulating physiological responses and biomineralization processes in juveniles of the Chilean scallop, Argopecten purpuratus, that were exposed to control (pH 8.0) and low pH (pH 7.6) conditions using three food supply treatments (high, intermediate, and low). We found that pH and food levels had additive effects on the physiological response of the juvenile scallops. Metabolic rates, shell growth, net calcification, and ingestion rates increased significantly at low pH conditions, independent of food. These physiological responses increased significantly in organisms exposed to intermediate and high levels of food supply. Hence, food supply seems to play a major role modulating organismal response by providing the energetic means to bolster the physiological response of OA stress. On the contrary, the relative expression of chitin synthase, a functional molecule for biomineralization, increased significantly in scallops exposed to low food supply and low pH, which resulted in a thicker periostracum enriched with chitin polysaccharides. Under reduced food and low pH conditions, the adaptive organismal response was to trade-off growth for the expression of biomineralization molecules and altering of the organic composition of shell periostracum, suggesting that the future performance of these calcifiers will depend on the trajectories of both OA and food supply. Thus, incorporating a suite of traits and multiple stressors in future studies of the adaptive organismal response may provide key insights on OA impacts on marine calcifiers.

  10. Contribution of food availability to the more rapid growth of the scallop, Euvola ziczac (Pteroida, Pectinidae in bottom than in suspended culture

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    Patrick Hunauld

    2005-09-01

    Full Text Available We conducted a 5-month experiment at Turpialito in the Golfo de Cariaco, Venezuela, to examine whether the previously reported more rapid growth of scallop Euvola ziczac in bottom compared to suspended culture can be attributed to more abundant or higher quality food resources near the sediment/water interface. The various body components (shell, muscle, digestive gland, gonad and remaining tissues increased in size at a much greater rate for scallops maintained on the bottom, in partly buried cages at 5 m in depth, than in cages suspended at the same depth in the water column. Furthermore, survival was greater on the bottom. Food abundance and quality were examined by analyzing the seston collected in sediment traps at the sediment/water interface in the vicinity of the bottom cages and next to the suspended cages. Phytoplankton abundance (chlorophyll a and the proportion of various fatty acids in the lipid fraction of the seston were similar on the bottom and in suspension. However, sestonic protein, lipid and carbohydrate levels, and the estimated energetic content of the seston, were higher on the bottom than in suspension, and probably contributed to the greater growth on the bottom. As the increase in the energetic content of the seston on the bottom compared to in suspension was less than the increase in growth (biomass on the bottom compared to in suspension, and the evidence showed in previous studies above the negative influence of fouling and wave action in suspended culture, we conclude that the more rapid growth of Euvola ziczac in bottom than suspended culture is principally due to stress relative to suspended culture system. Rev. Biol. Trop. 53(3-4: 455-461. Epub 2005 Oct 3.

  11. Artificial collection and early growth of spat of the scallop Argopecten purpuratus (Lamarck, 1819, in La Rinconada Marine Reserve, Antofagasta, Chile

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    Miguel Avendaño D.

    2007-03-01

    Full Text Available Artificial collection of early juveniles (“spat” of the scallop Argopecten purpuratus in Japanese-type collectors was evaluated between January 2001 and July 2002 in the La Rinconada Marine Reserve, Antofagasta, Chile. This area of Antofagasta Bay has in the past been noted for the retention of scallop larvae by local gyres, in which their numbers can vary between 89 and 34175 larvae m-3, producing larval sets of 400 to 15340 post-larvae (spat per collector. The results showed no quantitative relationship between larval abundance in the water and the spat density collected per day in the collectors, although high settlement rates were associated with high numbers of umboned larvae in the water. Allowing collectors to remain in situ for extended periods of 88 and 159 days resulted in a severe loss of seed which had settled in the collectors during the first 28 to 40 days of immersion. These losses varied between 50.9 and 99.6% of the spat collected, and were more prejudicial for the smaller cohorts that had settled in the collectors at the end of the first immersion period. The growth rates measured among different cohorts for each immersion period varied between 81.3 and 235.2 mm/day for the first cohort (C1 and between 64.0 and 167.4 mm/day for the second cohort (C2. The highest growth rates occurred in collectors containing the lowest numbers of spat after the occurrence of spat losses during the long periods of immersion. Occurrence of intraspecific competition within the collectors is discussed as potentially responsible for the decreases in spat numbers and the variations observed in their growth rates.

  12. Scalloped a member of the Hippo tumor suppressor pathway controls mushroom body size in Drosophila brain by non-canonical regulation of neuroblast proliferation.

    Science.gov (United States)

    Rohith, Basavanahalli Nanjundaiah; Shyamala, Baragur Venkatanarayanasetty

    2017-12-15

    Cell proliferation, growth and survival are three different basic processes which converge at determining a fundamental property -the size of an organism. Scalloped (Sd) is the first characterised transcriptional partner to Yorkie (Yki), the downstream effector of the Hippo pathway which is a highly potential and evolutionarily conserved regulator of organ size. Here we have studied the hypomorphic effect of sd on the development of Mushroom Bodies (MBs) in Drosophila brain. We show that, sd non-function results in an increase in the size of MBs. We demonstrate that, sd regulation on MB size operates through multiple routes. Sd expressed in the differentiated MB neurons, imposes non-cell autonomous repression on the proliferation of MB precursor cells, and Sd expression in the MB neuroblasts (NB) cell autonomously represses mushroom body neuroblast (MBNB) proliferation. Further Sd in Kenyon cells (KCs) imparts a cell autonomous restriction on their growth. Our findings are distinctive because, while the classical sd loss of function phenotypes in eye, wing and lymph gland are reported as loss of tissue or reduced organ size, the present study shows that, Sd inactivation in the developing MB, promotes precursor cell proliferation and results in an increase in the organ size. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. A scallop C-type lectin from Argopecten irradians (AiCTL5) with activities of lipopolysaccharide binding and Gram-negative bacteria agglutination.

    Science.gov (United States)

    Mu, Changkao; Song, Xiaoyan; Zhao, Jianmin; Wang, Lingling; Qiu, Limei; Zhang, Huan; Zhou, Zhi; Wang, Mengqiang; Song, Linsheng; Wang, Chunlin

    2012-05-01

    C-type lectins are a family of calcium-dependent carbohydrate-binding proteins. In the present study, a C-type lectin (designated as AiCTL5) was identified and characterized from Argopecten irradians. The full-length cDNA of AiCTL5 was of 673 bp, containing a 5' untranslated region (UTR) of 24 bp, a 3' UTR of 130 bp with a poly (A) tail, and an open reading frame (ORF) of 519 bp encoding a polypeptide of 172 amino acids with a putative signal peptide of 17 amino acids. A C-type lectin-like domain (CRD) containing 6 conserved cysteines and a putative glycosylation sites were identified in the deduced amino acid sequence of AiCTL5. AiCTL5 shared 11%-27.5% identity with the previous reported C-type lectin from A. irradians. The cDNA fragment encoding the mature peptide of AiCTL5 was recombined into pET-21a (+) with a C-terminal hexa-histidine tag fused in-frame, and expressed in Escherichia coli Origami (DE3). The recombinant AiCTL5 (rAiCTL5) agglutinated Gram-negative E. coli TOP10F' and Listonella anguillarum, but did not agglutinate Gram-positive bacteria Bacillus thuringiensis and Micrococcus luteus, and the agglutination could be inhibited by EDTA, indicating that AiCTL5 was a Ca(2+)-dependent lectin. rAiCTL5 exhibited a significantly strong activity to bind LPS from E. coli, which conformed to the agglutinating activity toward Gram-negative bacteria. Moreover, rAiCTL5 also agglutinated rabbit erythrocytes. These results indicated that AiCTL5 could function as a pattern recognition receptor to protect bay scallop from Gram-negative bacterial infection, and also provide evidence to understand the structural and functional diverse of lectin. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Short-Term Behavioural Responses of the Great Scallop Pecten maximus Exposed to the Toxic Alga Alexandrium minutum Measured by Accelerometry and Passive Acoustics.

    Science.gov (United States)

    Coquereau, Laura; Jolivet, Aurélie; Hégaret, Hélène; Chauvaud, Laurent

    2016-01-01

    Harmful algal blooms produced by toxic dinoflagellates have increased worldwide, impacting human health, the environment, and fisheries. Due to their potential sensitivity (e.g., environmental changes), bivalves through their valve movements can be monitored to detect harmful algal blooms. Methods that measure valve activity require bivalve-attached sensors and usually connected cables to data transfers, leading to stress animals and limit the use to sessile species. As a non-intrusive and continuously deployable tool, passive acoustics could be an effective approach to detecting harmful algal blooms in real time based on animal sound production. This study aimed to detect reaction changes in the valve movements of adult Pecten maximus exposed to the toxic dinoflagellate Alexandrium minutum using both accelerometry and passive acoustic methods. Scallops were experimentally exposed to three ecologically relevant concentrations of A. minutum for 2 hours. The number of each type of valve movement and their sound intensity, opening duration, and valve-opening amplitude were measured. Four behaviours were identified: closures, expulsion, displacement, and swimming. The response of P. maximus to A. minutum occurred rapidly at a high concentration. The valve activity of P. maximus was different when exposed to high concentrations (500 000 cells L-1) of A. minutum compared to the non-toxic dinoflagellate Heterocapsa triquetra; the number of valve movements increased, especially closure and expulsion, which were detected acoustically. Thus, this study demonstrates the potential for acoustics and sound production changes in the detection of harmful algal blooms. However, field trials and longer duration experiments are required to provide further evidence for the use of acoustics as a monitoring tool in the natural environment where several factors may interfere with valve behaviours.

  15. Short-Term Behavioural Responses of the Great Scallop Pecten maximus Exposed to the Toxic Alga Alexandrium minutum Measured by Accelerometry and Passive Acoustics.

    Directory of Open Access Journals (Sweden)

    Laura Coquereau

    Full Text Available Harmful algal blooms produced by toxic dinoflagellates have increased worldwide, impacting human health, the environment, and fisheries. Due to their potential sensitivity (e.g., environmental changes, bivalves through their valve movements can be monitored to detect harmful algal blooms. Methods that measure valve activity require bivalve-attached sensors and usually connected cables to data transfers, leading to stress animals and limit the use to sessile species. As a non-intrusive and continuously deployable tool, passive acoustics could be an effective approach to detecting harmful algal blooms in real time based on animal sound production. This study aimed to detect reaction changes in the valve movements of adult Pecten maximus exposed to the toxic dinoflagellate Alexandrium minutum using both accelerometry and passive acoustic methods. Scallops were experimentally exposed to three ecologically relevant concentrations of A. minutum for 2 hours. The number of each type of valve movement and their sound intensity, opening duration, and valve-opening amplitude were measured. Four behaviours were identified: closures, expulsion, displacement, and swimming. The response of P. maximus to A. minutum occurred rapidly at a high concentration. The valve activity of P. maximus was different when exposed to high concentrations (500 000 cells L-1 of A. minutum compared to the non-toxic dinoflagellate Heterocapsa triquetra; the number of valve movements increased, especially closure and expulsion, which were detected acoustically. Thus, this study demonstrates the potential for acoustics and sound production changes in the detection of harmful algal blooms. However, field trials and longer duration experiments are required to provide further evidence for the use of acoustics as a monitoring tool in the natural environment where several factors may interfere with valve behaviours.

  16. Neptuniibacter pectenicola sp. nov. and Neptuniibacter marinus sp. nov., two novel species isolated from a Great scallop (Pecten maximus) hatchery in Norway and emended description of the genus Neptuniibacter.

    Science.gov (United States)

    Diéguez, Ana L; Balboa, Sabela; Magnesen, Thorolf; Romalde, Jesús L

    2017-03-01

    Nine isolates obtained from a great scallop hatchery in Norway were characterized using a polyphasic approach. Strains were Gram-negative, aerobic and motile rods with oxidative metabolism. Phylogenetic analysis based on the sequences of 16S rRNA and rpoB genes showed that these strains formed two different groups associated with members of the genus Neptuniibacter. DNA-DNA hybridization (DDH) and Average Nucleotide Identity (ANI) demonstrated that the isolates constituted two novel species of this genus, which can be phenotypically differentiated from their closest relatives. The names Neptuniibacter marinus sp. nov. and Neptuniibacter pectenicola sp. nov are proposed, with ATR 1.1T (=CECT 8938T=DSM 100783T) and LFT 1.8T (=CECT 8936T=DSM 100781T) as respective type strains. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Morphological alterations in cryopreserved spermatozoa of scallop Argopecten purpuratus Alteraciones morfológicas en espermatozoides criopreservados de concha de abanico Argopecten purpuratus

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    Carlos Espinoza

    2010-01-01

    Full Text Available The present work identifies and quantifies the morphological alterations of scallop Argopecten purpuratus spermatozoa caused by long-term cryopreservation. Percentages of motility, fertilization and injured spermatozoa were quantified by optic microscopy and scanned electron microscopy. These parameters were evaluated in sperm without treatment (CTR, spermatozoa incubated in cryoprotective solution but not freezed (ICS and freezed-thawed spermatozoa (FTS. Spermatozoa of ICS treatment remained motile longer than those of CTR, whereas those of FTS treatment were lowest. Morphology of the spermatozoa was affected in several ways by the freeze-thawing treatment; some had their head deformed or swollen, others had their cell membrane folded or broken; acrosome reaction; anomalous positions or absence of mitochondria as well as broken, stiff or loss of lineal structure of tail. CTR and ICS treatments had higher percentages of undamaged sperm (87.7% and 79.0% respectively, while FTS samples had 14.2% of undamaged sperm. The tail was the spermatic structure most commonly injured in FTS (77.0%, the percentage of sperm with head injury was 55.1% and with acrosome reaction was 28.7%, whereas middle piece was affected in 23.9% of sperm. Percentages of fertilization were 68.3%, 67.9% and 58.2% for CTR, ICS and FTS respectively, which were not significantly different. There was a higher correlation between injuries and motility than between injuries and fertilization success. Correlation between motility and fertilization was low (0.605 and 0.668 with motility at 5 and 30 min, respectively.El presente trabajo identifica y cuantifica las alteraciones morfológicas en espermatozoides de concha de abanico A. purpuratus causadas por la criopreservación en nitrógeno líquido. Porcentajes de motilidad, fecundación de ovocitos frescos y espermatozoides lesionados (en cabeza, acrosoma, pieza media y flagelo fueron determinados bajo microscopía óptica y electr

  18. Performance Characteristics of AOAC Method 2005.06 for the Determination of Paralytic Shellfish Toxins in Manila Clams, European Otter Clams, Grooved Carpet Shell Clams, Surf Clams, and Processed King Scallops.

    Science.gov (United States)

    O'Neill, Alison; Turner, Andrew D

    2015-01-01

    An approach was developed for the verification of method performance of the AOAC 2005.06 LC-fluorescence detector (FLD) method for determination of paralytic shellfish poisoning (PSP) toxins in bivalve shellfish. This was developed following advice published by the Analytical Laboratory Accreditation Criteria Committee and applied to shellfish species that had not been previously subjected to a full single-laboratory validation scheme. The refined approach was developed following the need to assess performance in a number of shellfish species infrequently monitored through the UK statutory monitoring program, while reducing the impact and cost of the studies, most notably in terms of the use of valuable reference standards. The species assessed were manila clams (Ruditapes philippinarum), European otter clams (Lutraria lutraria), grooved carpet shell clams (R. decussatus), surf clams (Spisula solida), and king scallops (Pecten maximus) presented as adductor only or adductor plus roe. The method was assessed for sensitivity in terms of LOD and LOQ, toxin recovery, and method precision in each species. It incorporated the PSP toxins deemed toxic and/or prevalent in UK samples and commercially available as certified reference standards. The toxins studied included GTX1-5, dcSTX, STX, C1&2, and NEO. The toxins dcGTX2&3 were included for surf clams due to the prevalence of these toxins in this species as a result of toxin decarbamoylation. Method performance targets were met for each of the characteristics investigated. Consequently, the method was deemed fit for purpose for the screening and quantification of these clam and scallop species for PSP toxins by AOAC Method 2005.06 LC-FLD.

  19. Boom-to-bust. The scallop (Argopecten purpuratus) fishery in the Pisco-Paracas region, southern Peruvian coast Auge y crisis: la pesquería de la concha de abanico (Argopecten purpuratus) en la región Pisco-Paracas, costa sur del Perú

    OpenAIRE

    Ricardo M. González Hunt

    2010-01-01

    This paper examines scallop (Argopecten purpuratus) booms experienced in the Pisco-Paracas Region of southern Peru, triggered by the 1982-1983 and the 1997-1998 mega-El Niño Southern Oscillation (ENSO) events.The quiet fishing ports have been transformed by these booms, which have attracted outside stakeholders transforming the local society. Government institutions in their role as resource managers and environmental stewards have attempted to control access to a region that until recently c...

  20. Mercury and Selenium in Muscle and Target Organs of Scalloped Hammerhead Sharks Sphyrna lewini of the SE Gulf of California: Dietary Intake, Molar Ratios, Loads, and Human Health Risks.

    Science.gov (United States)

    Bergés-Tiznado, Magdalena E; Márquez-Farías, Fernando; Lara-Mendoza, Raúl E; Torres-Rojas, Yassir E; Galván-Magaña, Felipe; Bojórquez-Leyva, Humberto; Páez-Osuna, Federico

    2015-11-01

    Selenium and mercury were evaluated in muscle, liver, kidney, brain, and the stomach contents of juvenile scalloped hammerhead shark Sphyrna lewini. Se:Hg molar ratios were calculated. The average Hg levels in muscle ranged from 0.12 to 1.17 μg/g (wet weight); Hg was 1. Correlations were found for Hg in muscle with size, age, and weight, and also for Hg in liver with size, age, and weight. Hg in muscle was significantly positive correlated to Hg in brain as well as Hg in liver was correlated to Hg in kidney. The highest Hg in preys was for carangid fishes; scombrid and carangid fishes contributed with the highest Se levels. Results suggest that more than 98 % of the total Hg and 62 % of Se end up in muscle and might be affected by factors, such as geographical area, age, size, and feeding habits. The muscle of S. lewini should be consumed by people cautiously so as not to exceed the recommended intake per week.

  1. Filtration of sea louse, Lepeophtheirus salmonis, copepodids by the blue mussel, Mytilus edulis, and the Atlantic sea scallop, Placopecten magellanicus, under different flow, light and copepodid-density regimes.

    Science.gov (United States)

    Bartsch, A; Robinson, S M C; Liutkus, M; Ang, K P; Webb, J; Pearce, C M

    2013-03-01

    Population management of Lepeophtheirus salmonis in Canada currently relies on chemotherapeutants to remove attached stages of the ectoparasite. However, some populations of L. salmonis are developing resistance to chemotherapeutants making alternate management measures necessary. This article explores the ability of filter-feeding shellfish [i.e. blue mussels (Mytilus edulis) and Atlantic sea scallops (Placopecten magellanicus)] to consume the copepodid stages of L. salmonis in the laboratory under static and flowing water conditions, with variable copepodid densities, and with the aid of a light attractant. Mytilus edulis consumed copepodids under both static and flowing water conditions, and the proportion of individuals ingested was similar at low and high copepodid densities, suggesting that M. edulis was not saturated at the concentrations tested. Also, M. edulis consumed more copepodids when a light attractant was present, suggesting that lights may be useful to concentrate widely dispersed copepodids around cultured shellfish in the field. Finally, P. magellanicus consumed the same number of copepodids as an equivalent total wet weight of M. edulis. During each of the four separate experiments, shellfish consumed between 18 and 38% of the copepodids presented per hour, suggesting that both species are well suited for low level removal of copepodids over time. © Her Majesty the Queen in Right of Canada 2013.

  2. The Patagonian scallop fishing grounds in shelf break frontal areas: the non assessed benthic fraction Bancos de pesca de vieira patagónica en áreas del frente de talud: fracción bentónica no evaluada

    Directory of Open Access Journals (Sweden)

    María de los Ángeles Sánchez

    2011-01-01

    Full Text Available In this study, a Picard dredge was used to sample the benthic community in shelf break frontal areas off Argentina in order to detect species that could be sensitive to fishing activities but are not usually caught during the annual monitoring of Patagonian scallop and associated fauna. The present results show at least 62 taxa not reported previously as components of the benthos in the scallop grounds that are potentially subjected to trawling disturbance.En este trabajo se utilizó una rastra Picard para muestrear la comunidad bentónica en áreas del frente de talud, Argentina, para detectar especies que serían sensibles a la actividad pesquera pero no son capturadas usualmente durante los monitoreos anuales de vieira patagónica y fauna asociada. Los resultados muestran que al menos 62 taxa, no reportados previamente como componentes del bentos en los bancos de vieira, están potencialmente sujetos a perturbaciones por el arrastre.

  3. Influence of environmental factors on the growth of the juvenile, maturing juvenile, and adult tropical scallop, Euvola ziczac (Pteroida: Pectinidae, in suspended culture conditions Influencia de los factores ambientales en el crecimiento de juveniles, juveniles con capacidad reproductiva y adultos de la vieira tropical Euvola ziczac (Pteroida: Pectinidae en condiciones de cultivo suspendido

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    César Lodeiros

    2012-03-01

    Full Text Available We carried out growth trials on three size groups of the scallop, Euvola ziczac, during two short-term (34-36 days periods at 8, 21, and 34 m depth in Cariaco Gulf, Venezuela, in order to evaluate the effect of environmental factors on growth. Growth was greater in juveniles (initial size: 20-22 mm shell length than in maturing juveniles (30-40 mm and adults (70-75 mm. Somatic tissue growth was more than two-fold greater in juveniles than in maturing individuals. Adult scallops showed losses of tissue mass. The first period (December-January covered the transition from a stratified water column to upwelling conditions, with initial high temperatures and low phytoplankton biomass followed by lower temperatures and greater phytoplankton biomass. The second period (February-March consisted of upwelling, characterized by low temperatures and high phytoplankton production. The greater growth of juvenile and maturing scallops during the second period, particularly at 8 m depth, was associated with the greater availability of phytoplankton, related to coastal upwelling. The first development of gonads in maturing scallops only occurred in the second period, associated with food availability, and the degree of development was correlated with the depth. Our growth trials, which were too short to permit the negative impact of the development of fouling, showed that the growth of E. ziczac was enhanced in the presence of abundant phytoplankton biomass.Se efectuaron ensayos de crecimiento en tres grupos de tallas del pectínido Euvola ziczac, durante dos periodos de corto plazo (34-36 días a 8, 21 y 34 m de profundidad, en el golfo de Cariaco, Venezuela, para evaluar el efecto de factores ambientales en el crecimiento. El crecimiento fue mayor en juveniles (talla inicial 20-22 mm en longitud de concha, que en individuos madurando (30-40 mm y adultos (70-75 mm. El crecimiento del tejido somático fue más del doble en los juveniles que en los organismos en

  4. Age and growth of the Scalloped Hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834, from the southern Brazilian coast Idade e crescimento do tubarão-martelo-entalhado, Sphyrna lewini (Griffith and Smith, 1834, da costa sul do Brasil

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    JE. Kotas

    2011-08-01

    Full Text Available Age and growth studies for the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834 caught along the southern Brazilian coast, were based on ring measurements of vertebrae sections of 115 males, 116 females and 14 unknown sexed sharks between 48 and 344 cm total length (TL. The von Bertalanffy growth models were best fit using back-calculated data. The growth parameters obtained for males, were L∞ = 266 cm; K = 0.05/year; L0 = 47 cm. For females, L∞ = 300 cm; K = 0.05/year; L0 = 51 cm. An adult female reached 217 cm TL and was 31.5 years old. On the other hand, an adult male was 29.5 years old and measured 234 cm TL. Longevity estimate for males and females was 55 years. Therefore, S. lewini is a long-lived fish. Ageing precision, based on the IAPE index, was 5.6%. Marginal Increment analysis based on MIR index from hammerheads smaller than 105 cm, compared with the percentual of opaque and hyaline bands found per month ageing whole vertebrae, showed an annual ring formation, i.e., in winter.O estudo da idade e do crescimento do tubarão-martelo-entalhado, Sphyrna lewini (Griffith and Smith, 1834, na costa sul do Brasil, baseou-se na leitura de anéis em seções de vértebras de 115 machos, 116 fêmeas e de 14 exemplares com sexo indeterminado, com comprimentos totais (CT entre 48 e 344 cm. Modelos de crescimento de von Bertalanffy foram mais bem ajustados aos dados de idade e comprimento retrocalculados, considerando sexos em separado. Os parâmetros de crescimento obtidos para os machos foram L∞ = 266 cm; K = 0,05/ano; L0 = 47 cm. Para as fêmeas L∞ = 300 cm; K = 0,05/ano; L0 = 51 cm. Uma fêmea adulta atingiu um CT de 217 cm e uma idade de 31,5 anos. Por sua vez, um macho adulto tinha 29,5 anos e CT de 234 cm. A estimativa de longevidade para machos e fêmeas foi de 55 anos. O índice de erro percentual médio (IAPE, que avalia a precisão na leitura de idades, foi de 5,6%. A análise do incremento marginal baseada no

  5. Reproductive and larval cycle of the scallop Argopecten purpuratus (Ostreoida: Pectinidae, during El Niño-La Niña events and normal weather conditions in Antofagasta, Chile

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    Miguel Avendaño

    2008-03-01

    Full Text Available Seasonality, amplitude, and magnitude of spawning events were determined for Argopecten purpuratus in the La Rinconada marine reserve, Antofagasta, Chile, between December 1995 and January 2004. During the same period, samples of scallop larvae were obtained in vertical plankton hauls recovered within this reserve in an area routinely exposed to circular, gyre-like currents which helped retain the larvae within the bay. The reproduction of this population in normal or cool (e.g. "La Niña", 1998-2000 years occurred throughout the year, with a more active period between September and April, declining in June and August; this contrasted with the warmer "El Niño" oceanographic period of 1997-98 in which reproductive activity was more intense and prolonged throughout the entire year. The reproductive events in this population were mostly synchronous, although one asynchronous period occurred each year following the more intense March to May spawnings. This reproductive activity generated a continuous presence of larvae in the area in which no strict relation could be found between the intensities of spawning and numbers of larvae in the water. Larval presence was, however, generally correlated with active spawning periods. Important increases in larval numbers recorded at the end of 1999 and the beginning of 2003 were correlated with census data showing a higher percentage presence of broodstock over 90 mm in shell length during these years. An adequate stock of this size class is needed for a successful seed capture program in the reserve (for mass culture. Rev. Biol. Trop. 56 (1: 121-132. Epub 2008 March 31.Entre 1995 y 2004 se determinó, con el índice gonadosomático, el ciclo reproductivo de Argopecten purpuratus en La Rinconada, Antofagasta, Chile. Paralelamente se realizaron muestreos larvales mediante arrastres verticales de plancton. La reproducción, en años normales y fríos (La Niña, 1998-2000, ocurre todo el año, con un período m

  6. Boom-to-bust. The scallop (Argopecten purpuratus fishery in the Pisco-Paracas region, southern Peruvian coast Auge y crisis: la pesquería de la concha de abanico (Argopecten purpuratus en la región Pisco-Paracas, costa sur del Perú

    Directory of Open Access Journals (Sweden)

    Ricardo M. González Hunt

    2010-12-01

    Full Text Available This paper examines scallop (Argopecten purpuratus booms experienced in the Pisco-Paracas Region of southern Peru, triggered by the 1982-1983 and the 1997-1998 mega-El Niño Southern Oscillation (ENSO events.The quiet fishing ports have been transformed by these booms, which have attracted outside stakeholders transforming the local society. Government institutions in their role as resource managers and environmental stewards have attempted to control access to a region that until recently contained the only marine protected area of Peru.This situation has led to rapid growth in the scallop industry, the overexploitation and depletion of the shellfish, creating a sustainability crisis. Furthermore, this paper examines contradictions and relationships across local, regional, national, and international scales.Este trabajo examina los ciclos de expansión (boom de la explotación de la concha de abanico (Argopecten purpuratus observados en la región Pisco-Paracas del sur del Perú, resultantes de los fenómenos El Niño de 1982-1983 y 1997-1998.Los apacibles puertos de pesca han sido transformados por estos booms productivos que han atraído actores externos y han generado un impacto en la sociedad local. Las instituciones gubernamentales, en su papel de administradores de recursos y protectores del medio ambiente, han tratado de controlar el acceso a una región que hasta hace poco contenía la única área marina protegida del Perú.Esta situación ha producido un rápido crecimiento de la industria de la concha de abanico, su sobreexplotación y el agotamiento de dicho recurso, y ha producido una crisis de sostenibilidad. Asimismo, este trabajo examina las contradicciones y las relaciones entre las escalas local, regional, nacional e internacional.

  7. Simulation model of the scallop (Argopecten purpuratus farming in northern Chile: some applications in the decision making process Modelo de simulación para el cultivo del ostión (Argopecten purpuratus en el norte de Chile: aplicaciones para la toma de decisiones

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    Renato Molina

    2012-09-01

    Full Text Available Aquaculture farming is a complex system integrating several disciplines, including biology, engineering and economics, all which need to be correctly intertwined to have a profitable and environmentally sustainable activity. During the past recent years, scallop (Argopectenpurpuratus farmers in northern Chile have come to comprehend the hard way that aquaculture producers operate in a complex and dynamic environment where natural and economic factors are in constant change. Thus, to keep a profitable and competitive business in today's world, aquaculture farm managers are in need of relatively easy to use tools for efficient and timely decision making. Harvest size and time, mortality and growth rates, stocking rates, costs and market prices are important variables and parameters to monitor, where decisions with respect to their levels or values have to be made. In this context, non-linear and dynamic quantitative bioeconomic models should become valuable tools, for periodic decision making in the aquaculture business. This paper shows how to emulate Chilean scallop farming using a simulation model that mimics some of the industry's features. The model presented here focuses on a scallop aquaculture center that uses the common technology approach of pearl net and lanterns of the northern region of Chile, and analyses the farming strategies based on harvesting size. Also, these strategies were subject to variations in the parameters in order to identify patterns and asses the sensibility of the model to input values.La acuicultura es un sistema complejo que integra varias disciplinas, incluyendo la biología, ingeniería y economía, las cuales deben ser correctamente entrelazadas para lograr una actividad rentable y ambientalmente sostenible. Durante los últimos anos, los cultivadores del ostión del norte (Argopecten purpuratus en Chile han comprendido de la peor manera, que las actividades de acuicultura operan en un entorno complejo y din

  8. Asociación entre la tasa de autofecundación y la frecuencia de larvas malformadas en poblaciones cultivadas del ostión del norte Argopecten purpuratus (Lamarck, 1819 Association between self-fertilization rates and the frequency of malformed larvae in farmed populations of the northern scallop Argopecten purpuratus (Lamarck, 1819

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    Christopher Concha

    2011-07-01

    Full Text Available El incremento de la frecuencia de malformaciones y la reducción de la viabilidad y fecundidad suelen ser las primeras manifestaciones de la depresión por consanguinidad en animales. El ostión del norte, Argopectenpurpuratus (Lamarck, 1819, es una especie hermnafrodita funcional con autofecundación parcial y durante la reproducción artificial puede presentar altos grados de autofecundación. En este trabajo se analizó la asociación de la tasa de autofecundación con la frecuencia de larvas malformadas y la supervivencia larval. Se desovaron adultos maduros y se recogieron separadamente los gametos femeninos del 5° pulso de liberación en adelante y los masculinos. Los ovocitos fueron fecundados con espermatozoides de otro individuo, formando familias de hermanos completos. La tasa de autofecundación se verificó por la proporción de ovocitos que entra en división en una muestra de ellos sin fecundar. La tasa de autofecundación varió entre familias de 0 a 100%, con distribución de frecuencias normal. La proporción de larvas malformadas se distribuyó al azar entre las familias analizadas, pero se correlacionó negativamente, en forma moderada pero significativa, con la tasa de autofecundación y la temperatura media del cultivo. Los datos sugieren que la autofecundación en las familias de ostiones puede favorecer una mayor homeostasis del desarrollo larval.Increased frequencies of malformations and the reduction of viability and fecundity are some of the first manifestations of inbreeding depression in animals. The northern scallop, Argopecten purpuratus (Lamarck, 1819, is a functional hermaphrodite species with partial self-fertilization. During artificial reproduction, this species may present high degrees of self-fertilization. In this work, the association between the selfing rate and the frequency of larval malformations and survival were analyzed. Mature adults were spawned, and female and male gametes were collected

  9. Response of juvenile scalloped hammerhead sharks to electric stimuli.

    Science.gov (United States)

    Kajiura, Stephen M; Fitzgerald, Timothy P

    2009-01-01

    Sharks can use their electrosensory system to detect electric fields in their environment. Measurements of their electrosensitivity are often derived by calculating the voltage gradient from a model of the charge distribution for an ideal dipole. This study measures the charge distribution around a dipole in seawater and confirms the close correspondence with the model. From this, it is possible to predict how the sharks will respond to dipolar electric fields comprised of differing parameters. We tested these predictions by exposing sharks to different sized dipoles and levels of applied current that simulated the bioelectric fields of their natural prey items. The sharks initiated responses from a significantly greater distance with larger dipole sizes and also from a significantly greater distance with increasing levels of electric current. This study is the first to provide empirical evidence supporting a popular theoretical model and test predictions about how sharks will respond to a variety of different electric stimuli.

  10. Hooking mortality of scalloped hammerhead Sphyrna lewini and ...

    African Journals Online (AJOL)

    When these data are considered for potential management strategies to reduce the mortality of hammerhead sharks, a limitation on gear soak time would probably improve hammerhead shark survivorship. However, it may ... hammerheads. Keywords: bycatch, hook timer, logistic regression, soak time, time on the hook ...

  11. Comparative Analysis and Distribution of Omega-3 lcPUFA Biosynthesis Genes in Marine Molluscs.

    Science.gov (United States)

    Surm, Joachim M; Prentis, Peter J; Pavasovic, Ana

    2015-01-01

    Recent research has identified marine molluscs as an excellent source of omega-3 long-chain polyunsaturated fatty acids (lcPUFAs), based on their potential for endogenous synthesis of lcPUFAs. In this study we generated a representative list of fatty acyl desaturase (Fad) and elongation of very long-chain fatty acid (Elovl) genes from major orders of Phylum Mollusca, through the interrogation of transcriptome and genome sequences, and various publicly available databases. We have identified novel and uncharacterised Fad and Elovl sequences in the following species: Anadara trapezia, Nerita albicilla, Nerita melanotragus, Crassostrea gigas, Lottia gigantea, Aplysia californica, Loligo pealeii and Chlamys farreri. Based on alignments of translated protein sequences of Fad and Elovl genes, the haeme binding motif and histidine boxes of Fad proteins, and the histidine box and seventeen important amino acids in Elovl proteins, were highly conserved. Phylogenetic analysis of aligned reference sequences was used to reconstruct the evolutionary relationships for Fad and Elovl genes separately. Multiple, well resolved clades for both the Fad and Elovl sequences were observed, suggesting that repeated rounds of gene duplication best explain the distribution of Fad and Elovl proteins across the major orders of molluscs. For Elovl sequences, one clade contained the functionally characterised Elovl5 proteins, while another clade contained proteins hypothesised to have Elovl4 function. Additional well resolved clades consisted only of uncharacterised Elovl sequences. One clade from the Fad phylogeny contained only uncharacterised proteins, while the other clade contained functionally characterised delta-5 desaturase proteins. The discovery of an uncharacterised Fad clade is particularly interesting as these divergent proteins may have novel functions. Overall, this paper presents a number of novel Fad and Elovl genes suggesting that many mollusc groups possess most of the

  12. Comparative Analysis and Distribution of Omega-3 lcPUFA Biosynthesis Genes in Marine Molluscs.

    Directory of Open Access Journals (Sweden)

    Joachim M Surm

    Full Text Available Recent research has identified marine molluscs as an excellent source of omega-3 long-chain polyunsaturated fatty acids (lcPUFAs, based on their potential for endogenous synthesis of lcPUFAs. In this study we generated a representative list of fatty acyl desaturase (Fad and elongation of very long-chain fatty acid (Elovl genes from major orders of Phylum Mollusca, through the interrogation of transcriptome and genome sequences, and various publicly available databases. We have identified novel and uncharacterised Fad and Elovl sequences in the following species: Anadara trapezia, Nerita albicilla, Nerita melanotragus, Crassostrea gigas, Lottia gigantea, Aplysia californica, Loligo pealeii and Chlamys farreri. Based on alignments of translated protein sequences of Fad and Elovl genes, the haeme binding motif and histidine boxes of Fad proteins, and the histidine box and seventeen important amino acids in Elovl proteins, were highly conserved. Phylogenetic analysis of aligned reference sequences was used to reconstruct the evolutionary relationships for Fad and Elovl genes separately. Multiple, well resolved clades for both the Fad and Elovl sequences were observed, suggesting that repeated rounds of gene duplication best explain the distribution of Fad and Elovl proteins across the major orders of molluscs. For Elovl sequences, one clade contained the functionally characterised Elovl5 proteins, while another clade contained proteins hypothesised to have Elovl4 function. Additional well resolved clades consisted only of uncharacterised Elovl sequences. One clade from the Fad phylogeny contained only uncharacterised proteins, while the other clade contained functionally characterised delta-5 desaturase proteins. The discovery of an uncharacterised Fad clade is particularly interesting as these divergent proteins may have novel functions. Overall, this paper presents a number of novel Fad and Elovl genes suggesting that many mollusc groups possess

  13. Mercury accumulation in marine bivalves: influences of biodynamics and feeding niche.

    Science.gov (United States)

    Pan, Ke; Wang, Wen-Xiong

    2011-10-01

    Differences in the accumulation of mercury (Hg) in five species of marine bivalves, including scallops Chlamys nobilis, clams Ruditapes philippinarum, oysters Saccostrea cucullata, green mussels Perna viridis, and black mussels Septifer virgatus, were investigated. The bivalves displayed different patterns of Hg accumulation in terms of the body concentrations of methylmercury (MeHg) and total Hg (THg), as well as the ratio of MeHg to THg. Parameters of the biodynamics of the accumulation of Hg(II) and MeHg could reflect the species-dependent Hg concentrations in the bivalves. With the exception of black mussels, we found a significant relationship between the efflux rates of Hg(II) and the THg concentrations in the bivalves. The interspecific variations in the MeHg to THg ratio were largely controlled by the relative difference between the elimination rates of Hg(II) and MeHg. Stable isotope (δ(13)C) analysis indicated that the five bivalve species had contrasting feeding niches, which may also affect the Hg accumulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Toxicity of a secondary-treated sewage effluent to marine biota in Bass Strait, Australia: development of action trigger values for a toxicity monitoring program.

    Science.gov (United States)

    Adams, Merrin S; Stauber, Jennifer L; Binet, Monique T; Molloy, Robert; Gregory, David

    2008-01-01

    Melbourne Water's Eastern Treatment Plant (ETP) produces a secondary-treated sewage effluent which is chlorinated and discharged into Bass Strait at Boags Rocks, Victoria, Australia. Disappearance of the sensitive brown seaweed Hormosira banksii from rock platforms immediately adjacent to the shore-line discharge was identified in the early 1990s. Subsequently, Melbourne Water and CSIRO undertook an environmental impact assessment and review of land and marine effluent disposal options, which included ambient water quality monitoring, biological monitoring, bioaccumulation studies and toxicity testing of existing effluent to assess the nature and magnitude of the environmental effects. This paper presents data from the toxicity monitoring programs since 2001. Chronic toxicity testing using macroalgal germination and cell division (H. banksii), microalgal growth rate (Nitzschia closterium) and scallop larval development (Chlamys asperrima), confirmed that ammonia was the major cause of effluent toxicity. Results from this toxicity monitoring program were used to develop action trigger values for toxicity for each species, which were then used in a refined monitoring program in 2005-2007. An upgrade of the ETP is in progress to improve nitrification/denitrification in order to reduce ammonia concentrations and the toxicity of the effluent. Toxicity testing with a simulated upgraded effluent confirmed that ammonia concentrations and toxicity were reduced. Estimated "safe" dilutions of effluent, calculated using species sensitivity distributions, decreased from 1:140-300 for existing ETP effluent to 1:20 for nitrified effluent, further confirming that treatment improvements should reduce the impact on marine biota in the vicinity of the discharge.

  15. Scalloped hammerhead shark Sphyrna lewini, utilizes deep-water, hypoxic zone in the Gulf of California.

    Science.gov (United States)

    Jorgensen, S J; Klimley, A P; Muhlia-Melo, A F

    2009-05-01

    A hammerhead shark Sphyrna lewini tracked for 74 days revealed an expansion of the range of vertical distribution for the species to include the extreme hypoxic environment of the oxygen minimum layer in the Gulf of California.

  16. 78 FR 42890 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery and Northeast...

    Science.gov (United States)

    2013-07-18

    ... primary purpose of Joint Framework 24/49, developed by the New England Fishery Management Council (Council... public comment are not required for this rule by 5 U.S.C. 553, or any other law, the analytical...

  17. Effect of temperature on physiological responses of Peruvian scallop Argopecten purpuratus

    Directory of Open Access Journals (Sweden)

    Jhon Dionicio Acedo

    2015-12-01

    Full Text Available The effect of temperature on the clearance rate (CR, ingestion rate (IR and specific oxygen consumption (SOC in individuals of Argopecten purpuratus at different size groups were determined. The CR and IR tests were performed at a concentration of approximately 1x106 cel.mlL-1 of Chaetoceros calcitrans, two temperatures 17 and 22 °C were evaluated and different groups of average size were formed of 7.6 ± 0.265, and 0.058 ± 4.9 3.7 ± 0.173 cm. In SOC test the average size groups were 8.1 ± 0.351, 0.058 ± 5.6 and 4.3 ± 0.100 cm. The results show a significant effect of temperature in CR (Lh-1 and IR (cel.h-1 x 105 on the larger individuals (7.6 ± 0.265 cm, it was observed at 22 °C an average increase, about 17 °C, up to 250% to CR and 48% to IR. In addition, a direct relationship of body size with CR and IR in both temperatures was observed. The effect of temperature at 22 ° C on SOC in all groups was evaluated, with an increase of 239.8, 165.3 and 183.4% for size individuals of 8.1 ± 0.351, 0.058 ± 5.6 and 4.3 ± 0.100 respectively. Furthermore, in both evaluated temperatures, the results show an indirect relationship of body size with the SOC.

  18. Evolutionary divergence of geographic subspecies within the scalloped spiny lobster Panulirus homarus (Linnaeus 1758.

    Directory of Open Access Journals (Sweden)

    Shane D Lavery

    Full Text Available Panulirus homarus is an economically important spiny lobster that is widespread through the Indo-West Pacific Region, but has an uncertain taxonomic status, with three or four geographic subspecies having been described. This study used mitochondrial (16S, COI and control region and nuclear (18S, ITS-1 DNA sequences to examine specimens of all putative subspecies and forms from throughout their range, in order to determine their genetic validity, and understand the evolutionary history of this species. Despite the range of diversity present in the loci examined, the results were consistent across genes. P. h. rubellus from the SW Indian Ocean comprised the most divergent lineage that was reciprocally monophyletic with respect to all other P. homarus (approx. 9% divergence in COI, and has likely evolved reproductive barriers. The putative P. h. "Brown" subspecies from the Marquesas Is in the central Pacific also comprised a somewhat divergent monophyletic lineage (approx. 3% in COI, but may simply be an allopatric population. The widespread P. h. homarus was not diverged at all from the described P. h. megasculpta from the NW Indian Ocean. The degree of evolutionary divergence of populations at the extremes distribution of the species is somewhat surprising, given the long pelagic larval stage, but suggests that allopatric speciation has been an important driver in the evolution of the genus.

  19. 77 FR 20728 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery; Framework Adjustment 23

    Science.gov (United States)

    2012-04-06

    ... front of the depressor plate. (2) The angle between the front edge of the cutting bar and the top of the... a sea turtle passing under the dredge frame when the gear is on the seafloor, which could result in... LAGC IFQ vessels that fish with dredge gear greater than or equal to 10.5 feet (3.2 m) in width in the...

  20. Analysis of the scallop microbiota by means of 16S rRNA gene pyrosequencing

    OpenAIRE

    Alex Mira; Jesus L Romalde

    2014-01-01

    Bivalve molluscs, due to its filter-feeding mechanism, have an abundant associated bacterial microbiota composed of a large number of species of different genera. The knowledge about the composition of the microbiota associated with bivalve molluscs is based, mostly, on techniques of cultivation of microorganisms, but also on DGGE methods. However, it is estimated that less than 1% of the bacteria are culturable with current methods, which lead to an underestimation of the microbial diversity...

  1. 78 FR 27088 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery and Northeast...

    Science.gov (United States)

    2013-05-09

    ....32, which is the F associated with a 25-percent probability of exceeding the OFL. The Council's... management uncertainty buffer based on the F associated with a 75-percent probability of remaining below the... add more complexity to IFQ monitoring, and because NMFS is currently making a number of programming...

  2. 78 FR 16573 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery and Northeast...

    Science.gov (United States)

    2013-03-15

    ... on an F of 0.32, which is the ] F associated with a 25-percent probability of exceeding the OFL. The... management uncertainty buffer based on the F associated with a 75- percent probability of remaining below the... to how NMFS monitors the fishery, and does not involve extensive programming changes, NMFS would be...

  3. Analysis of the scallop microbiota by means of 16S rRNA gene pyrosequencing

    Directory of Open Access Journals (Sweden)

    Alex Mira

    2014-06-01

    Pyrosequencing of the samples resulted in a total of 18520 sequences (3000 per sample, approximately with an average length of 325 bp (base pairs. The taxonomic assignment of sequences allowed the identification to the genus level, being observed a large bacterial diversity with over 110 genera. The most prevalent genera in the samples were Hydrotalea, Acinetobacter, Delftia, Sediminibacter and Pseudomonas, among others. Differences in the microbial communities were observed among the samples, and the PCoA analysis allowed their separation by means on their gender and if they proceed from sampling before or after the spawning. Nevertheless, the rarefaction curves obtained for each sample failed to reach a saturation phase, indicating that more sequencing effort would be necessary.

  4. Sinobacterium norvegicum sp . nov., a new species isolated from scallop (Pecten maximus.

    Directory of Open Access Journals (Sweden)

    Anita Jacobsen

    2014-06-01

    The results of analysis of DNA-DNA hybridization confirmed that these isolates constitute a new and differentiated cluster within the genus Sinobacterium. The predominant fatty acids were C16: 0, C16: 1 ω7c/C16: 1 ω6c and C18: 1 ω7c. The G + C content of the new isolates is 52.2 ± 1 mol%. Based on phenotypic and phylogenetic characteristics, the seven isolates represent a new species for which the name Sinobacterium norvegicum sp. nov. is proposed, with strain 3CM4T (= CECT 8267T = CAIM 1884T as the type strain.

  5. Scalloped Implant-Abutment Connection Compared to Conventional Flat Implant-Abutment Connection

    DEFF Research Database (Denmark)

    Starch-Jensen, Thomas; Christensen, Ann-Eva; Lorenzen, Henning

    2017-01-01

    in combination with a hand-search of relevant journals was conducted. No language or year of publication restriction was applied. RESULTS: The search provided 298 titles. Three studies fulfilled the inclusion criteria. The included studies were characterized by low or moderate risk of bias. Survival...

  6. 75 FR 22073 - Fisheries of the Northeastern United States; Atlantic Sea Scallop Fishery; Framework Adjustment 21

    Science.gov (United States)

    2010-04-27

    ... submit attachments to electronic comments in Microsoft Word, Excel, WordPerfect, or Adobe PDF file... various rotational and permanent closures, as well as area-based differences in F, a lower F target should...

  7. Lower Oligocene bivalves of Ramanian Stage from Kachchh ...

    Indian Academy of Sciences (India)

    408. R P Kachhara et al. Ta b le. 1 . Check list a nd loca lity wise d istribution o f bivalves in. Kachchh. Lo cality. W a ior. B ermoti. Rakhdi. Sl. n o. S p ecies name. Lakhpat. W aior. Dam. S tream. D am. Geological range. 1. Chlamys. (. Chlamys. ) –. –. R. –. –. Low er. M io cene bhatiyaensis. Jain. 2. Chlamys. (. Aequ ipecten. ).

  8. Mercury accumulation in marine bivalves: Influences of biodynamics and feeding niche

    Energy Technology Data Exchange (ETDEWEB)

    Pan Ke [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2011-10-15

    Differences in the accumulation of mercury (Hg) in five species of marine bivalves, including scallops Chlamys nobilis, clams Ruditapes philippinarum, oysters Saccostrea cucullata, green mussels Perna viridis, and black mussels Septifer virgatus, were investigated. The bivalves displayed different patterns of Hg accumulation in terms of the body concentrations of methylmercury (MeHg) and total Hg (THg), as well as the ratio of MeHg to THg. Parameters of the biodynamics of the accumulation of Hg(II) and MeHg could reflect the species-dependent Hg concentrations in the bivalves. With the exception of black mussels, we found a significant relationship between the efflux rates of Hg(II) and the THg concentrations in the bivalves. The interspecific variations in the MeHg to THg ratio were largely controlled by the relative difference between the elimination rates of Hg(II) and MeHg. Stable isotope ({delta}{sup 13}C) analysis indicated that the five bivalve species had contrasting feeding niches, which may also affect the Hg accumulation. - Highlights: > Significant difference in Hg accumulation and MeHg:THg ratio in different bivalves. > THg concentrations in the bivalves were generally related to the efflux rates of Hg(II). > Elimination of Hg(II) and MeHg controlled the interspecific variation in MeHg:THg ratio. > MeHg and THg concentrations reflect the interaction of Hg biodynamics and food. - The species-specific body concentrations of MeHg and THg in bivalves reflect the complicated interaction between the biodynamics of Hg(II) and MeHg and the different food sources.

  9. Emerging and endemic types of Ostreid herpesvirus 1 were detected in bivalves in China.

    Science.gov (United States)

    Bai, Changming; Wang, Chongming; Xia, Junyang; Sun, Hailin; Zhang, Shuai; Huang, Jie

    2015-01-01

    Viral infection caused by Ostreid herpesvirus 1 (OsHV-1) is one of the proximate causes of mass mortalities of cultivated bivalves around the world. The emergence and spread of different variants of OsHV-1 accompanied by different epidemiological characteristics have been reported frequently in different countries around the world. In this paper, we present a study of the detection of OsHV-1 DNA and their variations from 1599 samples over 18 species collected in 27 aquaculture sites and two food markets during 2001-2013 in China. All of the samples were examined by a nested PCR assay targeting the C2/C6 fragment of OsHV-1 followed by sequencing. Our results showed 338 individuals (21.1%) of seven species sampled from 14 (14/27=51.9%) sites and the two food markets were positive for viral DNA. Sequencing of 289 PCR products revealed 24 virus types. No shared virus type was found among different countries with 47 types (23 in Japan, 16 in France, 2 in South Korea and 1 in each country of Australia, USA, Ireland, New Zealand, Mexico and China) identified in previous studies. As previously reported, two main phylogenetic groups were identified by phylogenetic analysis based on the 71 virus types; within which 6 separate clades were identified. Our results also demonstrated that two clades were associated with abnormal mortalities of the scallop, Chlamys farrier and the calm, Scapharca broughtonii in China. These findings indicated that cultivated bivalves may face potential threats from OsHV-1 types found in our study. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Peer-Reviewed Studies on the Effects of Anthropogenic Noise on Marine Invertebrates: From Scallop Larvae to Giant Squid.

    Science.gov (United States)

    de Soto, Natacha Aguilar

    2016-01-01

    Marine invertebrates at the base of oceanic trophic webs play important ecological and economical roles supporting worldwide fisheries worth millions. There is an increasing concern about the effects of anthropogenic noise on marine fauna but little is known about its effects on invertebrates. Here the current peer-reviewed literature on this subject is reviewed, dealing with different ontogenetic stages and taxa. These studies show that the noise effects on marine invertebrates range from apparently null to behavioral/physiological responses to mortalities. They emphasize the need to consider potential interactions of human activities using intense sound sources with the conservation and fisheries of local invertebrate stocks.

  11. Calcium oxide derived from waste shells of mussel, cockle, and scallop as the heterogeneous catalyst for biodiesel production.

    Science.gov (United States)

    Buasri, Achanai; Chaiyut, Nattawut; Loryuenyong, Vorrada; Worawanitchaphong, Phatsakon; Trongyong, Sarinthip

    2013-01-01

    The waste shell was utilized as a bioresource of calcium oxide (CaO) in catalyzing a transesterification to produce biodiesel (methyl ester). The economic and environmen-friendly catalysts were prepared by a calcination method at 700-1,000°C for 4 h. The heterogeneous catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller (BET) method. The effects of reaction variables such as reaction time, reaction temperature, methanol/oil molar ratio, and catalyst loading on the yield of biodiesel were investigated. Reusability of waste shell catalyst was also examined. The results indicated that the CaO catalysts derived from waste shell showed good reusability and had high potential to be used as biodiesel production catalysts in transesterification of palm oil with methanol.

  12. Growth and Development of Larval Bay Scallops (Argopecten irradians) in Response to Early Exposure to High CO2

    Science.gov (United States)

    2013-02-01

    coral   reefs  and  other  marine  calcifiers:  A  guide   for...unlimited. Edward A. Boyle MIT Director of Joint Program Approved for Distribution: Mark E. Hahn, Chair Department of Biology James A. Yoder WHO I Dean...CO2       by     Meredith  Megan  White     Submitted  to  the  Department  of   Biology   on  January

  13. Calcium Oxide Derived from Waste Shells of Mussel, Cockle, and Scallop as the Heterogeneous Catalyst for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Achanai Buasri

    2013-01-01

    Full Text Available The waste shell was utilized as a bioresource of calcium oxide (CaO in catalyzing a transesterification to produce biodiesel (methyl ester. The economic and environmen-friendly catalysts were prepared by a calcination method at 700–1,000°C for 4 h. The heterogeneous catalysts were characterized by X-ray diffraction (XRD, X-ray fluorescence (XRF, scanning electron microscopy (SEM, and the Brunauer-Emmett-Teller (BET method. The effects of reaction variables such as reaction time, reaction temperature, methanol/oil molar ratio, and catalyst loading on the yield of biodiesel were investigated. Reusability of waste shell catalyst was also examined. The results indicated that the CaO catalysts derived from waste shell showed good reusability and had high potential to be used as biodiesel production catalysts in transesterification of palm oil with methanol.

  14. SexuaJJy Transmitted Diseases in Malawi

    African Journals Online (AJOL)

    65% of ulcer patients and 57% of discharge patients). In Blantyre, where the .... cervicitis are treated simultaneously for gonorrhoea and chlamy- dial infections. This concept of the simultaneous treatment of two eti- ologies for several of the SID ...

  15. Application of calcium oxide (CaO, heated scallop-shell powder) for the reduction of Listeria monocytogenes biofilms on eggshell surfaces.

    Science.gov (United States)

    Park, S Y; Jung, S-J; Kang, I; Ha, S-D

    2017-12-13

    This study investigated bactericidal activity of 0.05 to 0.50% calcium oxide (CaO) against planktonic cells in tryptic soy broth (TSB) and biofilms of Listeria monocytogenes on eggshell surfaces. The bactericidal activity of CaO against planktonic cells and biofilms of L. monocytogens significantly (P < 0.05) increased log reductions with increasing concentrations of CaO. Exposure to 0.05 to 0.50% CaO for one min reduced planktonic cells in TSB cell suspensions by 0.47 to 3.86 log10CFU/mL and biofilm cells on the shell surfaces by 0.14 to 2.32 log10CFU/cm2. The Hunter colors of eggshells ("L" for lightness, "a" for redness, and "b" for yellowness), shell thickness (puncture force), and sensory quality (egg taste and yolk color) were not changed by 0.05 to 0.50% CaO treatment. The nonlinear Weibull model was used to calculate CR = 3 values as the CaO concentration of 3 log (99.9%) reduction for planktonic cells (R2 = 0.96, RMSE = 0.26) and biofilms (R2 = 0.95, RMSE = 0.18) of L. monocytogens. The CR = 3 value, 0.31% CaO for planktonic cells, was significantly (P < 0.05) lower than 0.57% CaO for biofilms. CaO could be an alternative disinfectant to reduce planktonic cells and biofilms L. monocytogenes on eggshell surface in egg processing plants. © 2017 Poultry Science Association Inc.

  16. Identification of mRNAs coding for mammalian-type melanin-concentrating hormone and its receptors in the scalloped hammerhead shark Sphyrna lewini.

    Science.gov (United States)

    Mizusawa, Kanta; Amiya, Noriko; Yamaguchi, Yoko; Takabe, Souichirou; Amano, Masafumi; Breves, Jason P; Fox, Bradley K; Grau, E Gordon; Hyodo, Susumu; Takahashi, Akiyoshi

    2012-10-01

    Melanin-concentrating hormone (MCH) is a neuromodulator, synthesized in the hypothalamus, that regulates both appetite and energy homeostasis in mammals. MCH was initially identified in teleost fishes as a pituitary gland hormone that induced melanin aggregation in chromatophores in the skin; however, this function of MCH has not been observed in other vertebrates. Recent studies suggest that MCH is involved in teleost feeding behavior, spurring the hypothesis that the original function of MCH in early vertebrates was appetite regulation. The present study reports the results of cDNAs cloning encoding preproMCH and two MCH receptors from an elasmobranch fish, Sphyrna lewini, a member of Chondrichthyes, the earliest diverged class in gnathostomes. The putative MCH peptide is composed of 19 amino acids, similar in length to the mammalian MCH. Reverse-transcription polymerase chain reaction revealed that MCH is expressed in the hypothalamus in S. lewini MCH cell bodies and fibers were identified by immunochemistry in the hypothalamus, but not in the pituitary gland, suggesting that MCH is not released via the pituitary gland into general circulation. MCH receptor genes mch-r1 and mch-r2 were expressed in the S. lewini hypothalamus, but were not found in the skin. These results indicate that MCH does not have a peripheral function, such as a melanin-concentrating effect, in the skin of S. lewini hypothalamic MCH mRNA levels were not affected by fasting, suggesting that feeding conditions might not affect the expression of MCH in the hypothalamus. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Bactericidal Effect of Calcium Oxide (Scallop-Shell Powder) Against Pseudomonas aeruginosa Biofilm on Quail Egg Shell, Stainless Steel, Plastic, and Rubber.

    Science.gov (United States)

    Jung, Soo-Jin; Park, Shin Young; Kim, Seh Eun; Kang, Ike; Park, Jiyong; Lee, Jungwon; Kim, Chang-Min; Chung, Myung-Sub; Ha, Sang-Do

    2017-07-01

    The aim of this study was to evaluate the bactericidal effect of calcium oxide (CaO) against Pseudomonas aeruginosa biofilms on quail eggshells and major egg contacting surfaces (stainless steel, plastic, and rubber). The samples were subjected to CaO treatments (0%, 0.01%, 0.05%, 0.10%, 0.15%, 0.20%, 0.25%, and 0.30%) for 1 min. All the CaO treatments significantly reduced P. aeruginosa biofilms on all tested surfaces as compared to controls. In comparison of biofilm stability, the strongest and most resistant biofilm was formed on eggshell against the CaO treatment, followed by rubber, stainless steel, and plastic. In evaluation of bactericidal effect, the largest reduction (3.16 log CFU) was observed in plastic even at the lowest concentration of CaO (0.01%), whereas the least reduction was found in eggshells, regardless of CaO concentration. In addition, stainless steel showed a significant reduction in biofilm formation at all concentrations except 0.10% to 0.15% CaO. At 0.30% CaO, the reduction of P. aeruginosa in biofilms on stainless steel, plastic, rubber, and eggshell were 5.48, 6.37, 4.87, and 3.14 log CFU/cm 2 (CFU/egg), respectively. Biofilm reduction after CaO treatment was also observed by field emission scanning electron microscopy (FE-SEM). Based on the FE-SEM images, we observed that P. aeruginosa biofilms formed compact aggregations on eggshell surfaces with CaO treatments up to 0.30%. More specifically, a 0.20% CaO treatment resulted in the reductions of 3 to 6 log CFU in all materials. © 2017 Institute of Food Technologists®.

  18. Primary Inhibition by Light: A Unique Property of Bivalve Photoreceptors

    National Research Council Canada - National Science Library

    Lon A. Wilkens

    2008-01-01

    ...) and the mantle eyes of scallops (Pectinidae) and file clams (Limidae). In scallops, they form a distal retinal layer of ciliary receptors, distinct from a proximal microvillar layer that is excited by light. In off-receptors (ciliary...

  19. 76 FR 16595 - Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the...

    Science.gov (United States)

    2011-03-24

    ... the most recent formal scallop resource stock assessment; An increase in the possession limit for... implement annual catch limits (ACLs) and accountability measures (AMs) to bring the Scallop FMP into... overfishing definition, modification of the essential fish habitat (EFH) closed areas under the Scallop FMP...

  20. 50 CFR 648.54 - State waters exemption.

    Science.gov (United States)

    2010-10-01

    ... (g) of this section. (c) Gear and possession limit restrictions. Any vessel issued a limited access scallop permit, an LAGC NGOM, or an LAGC IFQ scallop permit is exempt from the minimum twine top mesh size for scallop dredge gear specified in § 648.51(b)(4)(iv) while fishing exclusively landward of the...

  1. Annotations to the described and figured scallops (Mollusca, Bivalvia, Pectinidae) in the German, French and Dutch editions of Georg Wolfgang Knorr’s “Vergnügen” (1757-1775)

    NARCIS (Netherlands)

    Dijkstra, H.H.

    2010-01-01

    This paper deals with the described and figured Pectinidae of the three editions of Knorr’s “Vergnügen”. Plates are compared and treated taxonomically. Three new junior synonyms are recognized and ten figures are type figures of nominal taxa.

  2. [Evaluation of the first domestic immunoenzyme recombinant test-system "Khlami-IGA-DS-Tr" for detection of class A antibodies to Chlamydia trachomatis].

    Science.gov (United States)

    Manzeniuk, I N; Vorob'eva, M S; Nikitiuk, N M; Fedosov, S A; Losev, M V

    2002-06-01

    A test system for detecting species-specific class A antibodies to Chlamydia trachomatis, making use of recombinant chlamydial antigen, is developed in Russia for the first time. Its efficiency was demonstrated in blind clinical trials. The sensitivity, specificity, activity, and use of Chlamy-IgA-DC-Tr test system are not inferior to foreign analogs.

  3. Studying Hammerheads in Hawaii

    Science.gov (United States)

    Handler, Alex; Duncan, Kanesa

    2006-01-01

    In this article, the author discusses the High School Scalloped Hammerhead Shark Tagging Program in Hawaii which is an example of a successful partnership research collaboration. High school students and teachers worked with biologists from the University of Hawaii-Manoa (UHM) to conduct research on the life history of scalloped hammerhead sharks…

  4. Treatment outcome of two adjacent implant crowns with different implant platform designs in the aesthetic zone : A 1-year randomized clinical trial

    NARCIS (Netherlands)

    Tymstra, Nynke; Raghoebar, Gerry M.; Vissink, Arjan; Den Hartog, Laurens; Stellingsma, Kees; Meijer, Henny J. A.

    P>Aim To evaluate the peri-implant tissues in patients with two adjacent implant crowns in the aesthetic zone, treated with either two adjacent implants with a scalloped platform or with a flat platform. Material and methods Forty patients were randomly allocated to: (1) a "scalloped implant group":

  5. 50 CFR 648.51 - Gear and crew restrictions.

    Science.gov (United States)

    2010-10-01

    ... strengtheners, ropes, lines, or chafing gear, on the top of a trawl net, except that one splitting strap and one... top) possessed or used by vessels fishing with scallop dredge gear shall not be smaller than 10-inch... restrictions. No chafing gear or cookies shall be used on the top of a scallop dredge. (ii) Link restrictions...

  6. 75 FR 18355 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Framework Adjustment 44

    Science.gov (United States)

    2010-04-09

    ... = Southern New England/Mid-Atlantic; CC = Cape Cod/GOM; plaice = American plaice; witch = witch flounder... the current Atlantic Sea Scallop FMP, if the scallop fishery harvests in excess of the yellowtail... of the fishery (72.5 percent and 27.5 percent for haddock; 66.3 percent and 33.7 percent for cod...

  7. 75 FR 5016 - Fisheries of the Northeastern United States; Northeast Multispecies Fishery; Framework Adjustment 44

    Science.gov (United States)

    2010-02-01

    ... (particularly for GOM cod and pollock). In particular, industry members noted that fishery participants may.../Mid-Atlantic; CC = Cape Cod/GOM; plaice = American plaice; witch = witch flounder; winter = winter... Atlantic Sea Scallop FMP, if the scallop fishery harvests in excess of the yellowtail flounder sub...

  8. 76 FR 11857 - Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the...

    Science.gov (United States)

    2011-03-03

    ..., offshore hake, and ocean pout; while large- mesh species include Atlantic cod, haddock, yellowtail flounder...- Stock Total ACL ACL Scallop fishery herring fishery sub-component components GB cod 4,540 4,301 0 0 48... Scallop fishery herring fishery sub-component components GB cod 5,109 4,841 0 0 54 215 GB haddock 27,637...

  9. 50 CFR 648.11 - At-sea sea sampler/observer coverage.

    Science.gov (United States)

    2010-10-01

    ... sampler/observer in a timely fashion of when fishing operations are to begin and end. (5) Allow for the... any scallop trip of the time, port of departure, open area or specific Sea Scallop Access Area to be.../NEFOP must be notified by the owner, operator, or vessel manager of any trip plan changes at least 48 hr...

  10. to view fulltext PDF

    Indian Academy of Sciences (India)

    Xu Y., Liu J., Lan X., Zhang Y., Lei C., Zhang C., Yang D. and Chen H. 2011 Consistent effects of single and combined SNP(s) within bovine paired box 7 gene (Pax7) on ... polymorphic microsatellite markers from the cDNA library of Japanese scallop Mizuhopecten yessoensis and cross-species amplification in bay scallop ...

  11. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Characterization of novel polymorphic microsatellite markers from the cDNA library of Japanese scallop Mizuhopecten yessoensis and cross-species amplification in bay scallop Argopecten irradians · Xiang Ying Meng Xiu Li Wang Xiao Li Guo Meng Chen Ying Ming Zhang Hong Yue Wang Ya Qing Chang Xue Mei Qiu.

  12. Dicty_cDB: Contig-U10738-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available DQ302781 ) Glomus mosseae isolate AFTOL-ID 139 RNA polymeras... 60 1e-38 9 ( DQ302793 ) Rhizophydium macropo...zophydium macroporosum isolate ... 275 3e-72 DQ020659_1( DQ020659 |pid:none) Chlamy...1( AY699210 |pid:none) Juniperus communis RNA polymerase ... 246 3e-72 DQ302793_1( DQ302793 |pid:none) Rhi

  13. 76 FR 66694 - New England Fishery Management Council (NEFMC); Public Meeting

    Science.gov (United States)

    2011-10-27

    ... relevant to the management of sandbar, dusky, and blacknose shark, and on a new status determination for scalloped hammerhead based on recent stock assessments for these species. Although other non-emergency...

  14. Shellfish Allergy

    Science.gov (United States)

    ... about food allergies. Advocacy Resources Community Resources Teal Pumpkin Project Education Network Food for Thought Video Series ... urchin Scallops Snails (escargot) Squid (calamari) Whelk (Turban shell) *Note: The federal government does not require mollusks ...

  15. A Comparison of the foraging ecology and bioenergetics of the early life-stages of two sympatric hammerhead sharks from 1998-07-12 to 2005-07-27 (NCEI Accession 0163192)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Archival Information Package (AIP) contains basic biological information on bonnethead and scalloped hammerhead sharks with specific (by stomach and prey item)...

  16. OBPRELIM Observer Preliminary Data System

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Paper logs are the primary data collection tool used by observers of the Northeast Fisheries Observer Program and Industry Funded Scallop Program deployed on...

  17. 78 FR 54240 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2013-09-03

    ... held at the Best Western Hotel, 580 US Highway 1, Interstate Traffic Circle, Portsmouth, NH 03801... biological opinion of the sea scallop fishery related to sea turtles and Atlantic Sturgeon. There will be a...

  18. The biochemical textural and sensory properties of frozen stored ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-18

    . Key words: Scallop meats, frozen .... A portion (0.5 ml) of this filtrate was used for the determination of thiobarbituric acid reactive substances ..... mechanism of fish muscle proteins by maltodextrins. Cryobiology, 38: 16-26.

  19. A Climatological Oil Spill Planning Guide. Number 2. Gulf of Maine/Georges Bank,

    Science.gov (United States)

    1981-06-01

    Shellfish Distribution: Sea scallops and bay scallops . . . 99 76 Shellfish Distribution: American oyster .......... 100 77 Lobster Distribution...Sandy Hook to Bay of Fundy , Vol. I, Book I Submitted to Bureau of Land Management (08550- CT-S outh Portland, Maine; TRIGOK, November, 1974. Research...6?󈨆 Offite Shtateie Oft Shorn F...................45 44- ,7440 N. e.... ..... .... 430 43’ 41* 1 710 700 69, 680 6?’ 66’ Figure 77.-- Lobster

  20. Echocardiographic anatomy of the mitral valve: a critical appraisal of 2-dimensional imaging protocols with a 3-dimensional perspective.

    Science.gov (United States)

    Mahmood, Feroze; Hess, Philip E; Matyal, Robina; Mackensen, G Burkhard; Wang, Angela; Qazi, Aisha; Panzica, Peter J; Lerner, Adam B; Maslow, Andrew

    2012-10-01

    To highlight the limitations of traditional 2-dimensional (2D) echocardiographic mitral valve (MV) examination methodologies, which do not account for patient-specific transesophageal echocardiographic (TEE) probe adjustments made during an actual clinical perioperative TEE examination. Institutional quality-improvement project. Tertiary care hospital. Attending anesthesiologists certified by the National Board of Echocardiography. Using the technique of multiplanar reformatting with 3-dimensional (3D) data, ambiguous 2D images of the MV were generated, which resembled standard midesophageal 2D views. Based on the 3D image, the MV scallops visualized in each 2D image were recognized exactly by the position of the scan plane. Twenty-three such 2D MV images were created in a presentation from the 3D datasets. Anesthesia staff members (n = 13) were invited to view the presentation based on the 2D images only and asked to identify the MV scallops. Their responses were scored as correct or incorrect based on the 3D image. The overall accuracy was 30.4% in identifying the MV scallops. The transcommissural view was identified correctly >90% of the time. The accuracy of the identification of A1, A3, P1, and P3 scallops was <50%. The accuracy of the identification of A2P2 scallops was ≥50%. In the absence of information on TEE probe adjustments performed to acquire a specific MV image, it is possible to misidentify the scallops. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Effects of varying obliquity on Martian sublimation thermokarst landforms

    Science.gov (United States)

    Dundas, Colin M.

    2017-01-01

    Scalloped depressions in the Martian mid-latitudes are likely formed by sublimation of ice-rich ground. The stability of subsurface ice changes with the planetary obliquity, generally becoming less stable at lower axial tilt. As a result, the relative rates of sublimation and creep change over time. A landscape evolution model shows that these variations produce internal structure in scalloped depressions, commonly in the form of arcuate ridges, which emerge as depressions resume growth after pausing or slowing. In other scenarios, the formation of internal structure is minimal. Significant uncertainties in past climate and model parameters permit a range of scenarios. Ridges observed in some Martian scalloped depressions could date from obliquity lows or periods of low ice stability occurring <5 Ma, suggesting that the pits are young features and may be actively evolving.

  2. The benthic association between a bivalve and a shell boring polychaete and their potential food sources

    Science.gov (United States)

    Silina, A. V.; Zhukova, N. V.

    2012-09-01

    The trophic relationships in the association of the Yeso scallop Mizuhopecten yessoensis and its dominant endobiontic polychaete Polydora brevipalpa, which burrows into the scallop's shell, and their potential food sources were studied using the method of fatty acid biochemical markers. It is shown that the differences in the diet of the scallop and the polychaete allow them to coexist in a close association. The trophic role of the association in the benthic community was revealed. The association selectively utilizes the food sources of the environment. It almost does not consume organic matter of bottom sediments, which allows it to coexist with other species in the community of higher order. There is minimal food competition between the association and detritivorous species; however, association can limit the development of species mostly foraging on diatom algae.

  3. Treatment of severe mitral regurgitation caused by lesions in both leaflets using multiple mitral valve plasty techniques in a small dog

    Directory of Open Access Journals (Sweden)

    Satoko Yokoyama

    2017-11-01

    Full Text Available Mitral valve plasty (MVP is preferred over mitral valve replacement (MVR for mitral regurgitation in humans because of its favorable effect on quality of life. In small dogs, it is difficult to repair multiple lesions in both leaflets using MVP. Herein, we report a case of severe mitral regurgitation caused by multiple severe lesions in the posterior leaflet (PL in a mixed Chihuahua. Initially, we had planned MVR with an artificial valve. However, MVP combined with artificial chordal reconstruction of both leaflets, semicircular suture annuloplasty, and valvuloplasty using a newly devised direct scallop suture for the PL was attempted in this dog. The dog recovered well and showed no adverse cardiac signs, surviving two major operations. The dog died 4 years and 10 months after the MVP due to non-cardiovascular disease. Our additional technique of using a direct scallop suture seemed useful for PL repair involving multiple scallops in a small dog.

  4. Venus - Volcano With Massive Landslides

    Science.gov (United States)

    1992-01-01

    This Magellan full-resolution mosaic which covers an area 143 by 146 kilometers (89 by 91 miles) is centered at 55 degrees north latitude, 266 degrees east longitude. The bright feature, slightly south of center is interpreted to be a volcano, 15-20 kilometers (9.3 to 12.4 miles) in diameter with a large apron of blocky debris to its right and some smaller aprons to its left. A preferred explanation is that several massive catastrophic landslides dropped down steep slopes and were carried by their momentum out into the smooth, dark lava plains. At the base of the east-facing or largest scallop on the volcano is what appears to be a large block of coherent rock, 8 to 10 kilometers (5 to 6 miles) in length. The similar margin of both the scallop and block and the shape in general is typical of terrestrial slumped blocks (masses of rock which slide and rotate down a slope instead of breaking apart and tumbling). The bright lobe to the south of the volcano may either be a lava flow or finer debris from other landslides. This volcanic feature, characterized by its scalloped flanks is part of a class of volcanoes called scalloped or collapsed domes of which there are more than 80 on Venus. Based on the chute-like shapes of the scallops and the existence of a spectrum of intermediate to well defined examples, it is hypothesized that all of the scallops are remnants of landslides even though the landslide debris is often not visible. Possible explanations for the missing debris are that it may have been covered by lava flows, the debris may have weathered or that the radar may not be recognizing it because the individual blocks are too small

  5. Neutronics of a mixed-flow gas-core reactor

    Energy Technology Data Exchange (ETDEWEB)

    Soran, P.D.; Hansen, G.E.

    1977-11-01

    The study was made to investigate the neutronic feasibility of a mixed-flow gas-core reactor. Three reactor concepts were studied: four- and seven-cell radial reactors and a seven-cell scallop reactor. The reactors were fueled with UF/sub 6/ (either U-233 or U-235) and various parameters were varied. A four-cell reactor is not practical nor is the U-235 fueled seven-cell radial reactor; however, the 7-cell U-233 radial and scallop reactors can satisfy all design criteria. The mixed flow gas core reactor is a very attractive reactor concept and warrants further investigation.

  6. Bias-Variance Tradeoffs in Recombination Rate Estimation.

    Science.gov (United States)

    Stone, Eric A; Singh, Nadia D

    2016-02-01

    In 2013, we and coauthors published a paper characterizing rates of recombination within the 2.1-megabase garnet-scalloped (g-sd) region of the Drosophila melanogaster X chromosome. To extract the signal of recombination in our high-throughput sequence data, we adopted a nonparametric smoothing procedure, reducing variance at the cost of biasing individual recombination rates. In doing so, we sacrificed accuracy to gain precision-precision that allowed us to detect recombination rate heterogeneity. Negotiating the bias-variance tradeoff enabled us to resolve significant variation in the frequency of crossing over across the garnet-scalloped region. Copyright © 2016 by the Genetics Society of America.

  7. 78 FR 44095 - Atlantic Highly Migratory Species; Meeting of the Atlantic Highly Migratory Species Advisory Panel

    Science.gov (United States)

    2013-07-23

    ...; shark management measures regarding rebuilding scalloped hammerhead and blacknose sharks (Amendment 5a), rebuilding dusky sharks (Amendment 5b), and shark catch shares (Amendment 6); and swordfish management... Atlantic tunas, swordfish, billfish, and sharks. The AP has previously consulted with NMFS on: Amendment 1...

  8. Hammerhead Shark Research Immersion Program: Experiential Learning Leads to Lasting Educational Benefits

    Science.gov (United States)

    Handler, Alex; Duncan, Kanesa

    2006-01-01

    High school students (n = 45) participated in a 5-day research immersion study on juvenile scalloped hammerhead sharks in Kaneohe Bay, Oahu, Hawaii. Self-surveys were used to evaluate scientific concepts and skills taught during the program. There was a significant shift in students' perceived level of understanding for all categories of concepts…

  9. 77 FR 52314 - Atlantic Highly Migratory Species; Meeting of the Atlantic Highly Migratory Species Advisory Panel

    Science.gov (United States)

    2012-08-29

    ... tuna management (Amendment 7), shark management measures such as rebuilding scalloped hammerhead, dusky, and blacknose sharks (Amendment 5) and catch shares, swordfish management measures (Amendment 8), and..., swordfish, billfish, and sharks. The AP has previously consulted with NMFS on: Amendment 1 to the Billfish...

  10. 77 FR 4282 - Atlantic Highly Migratory Species; Meeting of the Atlantic Highly Migratory Species Advisory Panel

    Science.gov (United States)

    2012-01-27

    ... tuna management; revitalizing the swordfish fishery; shark management measures such as rebuilding scalloped hammerhead, dusky, and blacknose sharks and catch shares; and items contained in the Advanced... FMP amendments for Atlantic tunas, swordfish, billfish, and sharks. The AP has previously consulted...

  11. Louisiana Coastal Area, Louisiana. Notice of Study Findings. Water Supply

    Science.gov (United States)

    1984-09-01

    Spotted seatrout Atlantic sharpnose shark Spot Scalloped hammerhead Southern kingfish Tarpon Gulf kingfish Gulf menhaden Atlantic croaker Atlantic thread...commercial or recreational importance in the study area. Species Bull shark Sheepshead Blacktip shark Silver perch Tiger shark Sand seatrout Lemon shark

  12. Louisiana Coastal Area, Louisiana. Land Loss and Marsh Creation

    Science.gov (United States)

    1984-11-01

    Blacktip shark Silver perch Tiger shark Sand seatrout Lemon shark Spotted seatrout Atlantic sharpnose shark Spot Scalloped hammerhead Southern kingfish...list of common estuarine and marine fishes and shellfishes of commercial or recreational importance in the study area. Species Bull shark Sheepshead

  13. 78 FR 279 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

    Science.gov (United States)

    2013-01-03

    ... scalloped hammerhead sharks indicated that these species are overfished and experiencing overfishing. As... Species (HMS) Fishery Management Plan (FMP) in response to several shark stock assessments that were... fishing mortality and effort in order to rebuild overfished Atlantic shark species while ensuring that a...

  14. Molluscan Evolutionary Development

    DEFF Research Database (Denmark)

    Wanninger, Andreas Wilhelm Georg; Koop, Damien; Moshel-Lynch, Sharon

    2008-01-01

    anatomical diversity and include the bivalves (scallops, oysters, and clams), gastropods (limpets, snails, and slugs), and cephalopods (squid, cuttlefish, and octopus). This study treats each major taxon and supplies general information as well as overviews of evolution and phylogeny using data from...

  15. Fulltext PDF

    Indian Academy of Sciences (India)

    Quililongo C. J., Rıos-Ramırez M. A., Velásquez-Cumplido L., Morales-Mun˜oz B. and Escobar-Fica J. A. 2012 Development and characterization of ten polymorphic microsatellites isolated from the scallop Argopecten purpuratus. J. Genet.

  16. Cephalopods in the diets of four shark species ( galeocerdo Cuvier ...

    African Journals Online (AJOL)

    Cephalopods in the diets of four shark species ( galeocerdo Cuvier, sphyrna lewini , S. Zygaena and S. Mokarran) from Kwazulu-Natal, South Africa. ... The cephalopod components of the diets of four species of shark, tiger Galeocerdo cuvier, smooth hammerhead Sphyrna zygaena, scalloped hammerhead S. lewini and ...

  17. Isolated posterior fossa involvement of progressive multifocal ...

    African Journals Online (AJOL)

    2017-11-14

    Nov 14, 2017 ... Open Access frontal lobe. Supratentorial lesions typically involve the subcortical white matter with a scalloping appearance.2. White matter of the posterior fossa is the next common area of involvement; however, isolated cerebellar white matter or isolated medullary involvement is less common.2. One study ...

  18. Functional Paraganglioma: A Rare Conus‑cauda Lesion

    African Journals Online (AJOL)

    traumatic injury, disk herniation, spinal stenosis, spinal tumors, infectious conditions, and accidental causes by medical intervention (iatrogenic causes). .... Figure 4: X-ray of the Dorso-lumbar region showing significant scalloping of posterior margin of L1 vertebral bodies and their posterior elements. Figure 2: T2W axial ...

  19. 78 FR 15934 - North Pacific Fishery Management Council; Public Meetings

    Science.gov (United States)

    2013-03-13

    ...; Industry progress report on BSAI Chum salmon bycatch; Update on salmon genetics research. 8. Miscellaneous.... ADDRESSES: The meetings will be held at the Anchorage Hilton Hotel, 500 West 3rd Avenue, Anchorage, AK...) analytical methods. (SSC only) 5. Scallop Stock Assessment Fishery Evaluation (SAFE): Review and approve...

  20. 75 FR 41818 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-07-19

    .... Although non-emergency issues not contained in this agenda may come before this group for discussion, those... group will be brought to the full Council for formal consideration and action, if appropriate. DATES... primarily focused on issues relevant to the limited access scallop fishery, and a second panel primarily...

  1. Single Laboratory Validation of A Ready-to-Use Phosphatase Inhibition Assay for Detection of Okadaic Acid Toxins

    Directory of Open Access Journals (Sweden)

    Luis Mata

    2012-04-01

    Full Text Available A phosphatase inhibition assay for detection of okadaic acid (OA toxins in shellfish, OkaTest, was single laboratory validated according to international recognized guidelines (AOAC, EURACHEM. Special emphasis was placed on the ruggedness of the method and stability of the components. All reagents were stable for more than 6 months and the method was highly robust under normal laboratory conditions. The limit of detection and quantification were 44 and 56 µg/kg, respectively; both below the European legal limit of 160 µg/kg. The repeatability was evaluated with 2 naturally contaminated samples. The relative standard deviation (RSD calculated was 1.4% at a level of 276 µg/kg and 3.9% at 124 µg/kg. Intermediate precision was estimated by testing 10 different samples (mussel and scallop on three different days and ranged between 2.4 and 9.5%. The IC50 values of the phosphatase used in this assay were determined for OA (1.2 nM, DTX-1 (1.6 nM and DTX-2 (1.2 nM. The accuracy of the method was estimated by recovery testing for OA (mussel, 78–101%; king scallop, 98–114%, DTX-1 (king scallop, 79–102% and DTX-2 (king scallop, 93%. Finally, the method was qualitatively compared to the mouse bioassay and LC-MS/MS.

  2. 75 FR 51240 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-08-19

    ... group will be brought to the full Council for formal consideration and action, if appropriate. DATES... further clarifications about new monitoring requirements for annual catch limits in the scallop fishery. In addition, the Committee will discuss possible modifications to the current overfishing definition...

  3. 76 FR 43745 - Magnuson-Stevens Fishery Conservation and Management Act (MSA) Provisions; Fisheries of the...

    Science.gov (United States)

    2011-07-21

    ... account for management uncertainty, Amendment 15 establishes ACTs for each fleet. For the LA fleet, the... landed (i.e., not to the FY for which they were allocated). 7. Management Uncertainty and ACT Amendment 15 specifies that management uncertainty in the scallop fishery mainly results from the uncertainty...

  4. 76 FR 19929 - Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the...

    Science.gov (United States)

    2011-04-11

    ... LAGC fisheries. To account for management uncertainty, Amendment 15 proposes ACTs for each fleet. For.... Management Uncertainty and ACT Amendment 15 proposes that management uncertainty in the scallop fishery... during the course of the fishing year. Management uncertainty for the LAGC IFQ fleet is considered very...

  5. Comprehension: The Challenge for Children's Television.

    Science.gov (United States)

    Storm, Susan R.

    The purpose of this research was to determine young children's comprehension of selected TV program content. The subjects were 210 children in grades K-2. All subjects in groups of five, were shown segments from four TV programs: a scalloped potatoes commercial, a "Batman" and Robin episode, a news story on the MIG-25 and a segment of the…

  6. Development and characterization of ten polymorphic microsatellites ...

    Indian Academy of Sciences (India)

    Quililongo C. J., Ríos-Ramírez M. A., Velásquez-Cumplido L., Morales-Muñoz B. and Escobar-Fica J. A. 2012 Development and characterization of ten polymorphic microsatellites isolated from the scallop Argopecten purpuratus. J. Genet.

  7. 78 FR 20717 - Endangered and Threatened Wildlife and Plants; Proposed Endangered, Threatened, and Not Warranted...

    Science.gov (United States)

    2013-04-05

    ... Mechanisms section). In Brazilian waters, there are very few fishery regulations that help protect hammerhead populations. For example, the minimum legal size for a scalloped hammerhead caught in Brazilian waters is 60... commodity and as a dietary staple. In fact, many people in Sub-Saharan Africa depend on fish for protein in...

  8. Mercury's shifting, rolling past

    OpenAIRE

    Trulove, Susan

    2008-01-01

    Patterns of scalloped-edged cliffs or lobate scarps on Mercury's surface are thrust faults that are consistent with the planet shrinking and cooling with time. However, compression occurred in the planet's early history and Mariner 10 images revealed decades ago that lobate scarps are among the youngest features on Mercury. Why don't we find more evidence of older compressive features?

  9. Radiology of back pain

    Energy Technology Data Exchange (ETDEWEB)

    Wackenheim, A.; Dietemann, J.L.

    1983-04-01

    The authors give an overview of causes of back pain which may be detected by radiological examinations. They insist on practical points of view such as: main cause, accessory cause, problems arising by multiple causes, congenital malformation of the vertebral arch such as anisocoria, canalar stenosis, cheirolumbar dysostosis. They describe two new signs: the pedicular scalloping and the framed articular process.

  10. 75 FR 32375 - New England Fishery Management Council; Public Meeting

    Science.gov (United States)

    2010-06-08

    ... Council (Council) will hold a three-day Council meeting on Tuesday through Thursday, June 22-24, 2010, to... Scallop Committee. The afternoon session will begin with an overview of the status of spiny dogfish by the... on progress to date concerning its ABC control rules, five-year research priorities and an ecosystem...

  11. 78 FR 65963 - Submission for OMB Review; Comment Request

    Science.gov (United States)

    2013-11-04

    ... scallops in the Northeast United States. It also seeks to collect data on business disruptions due to... Administration (NOAA). Title: Survey of Fish Processors and Business Disruptions Caused by Hurricane Sandy. OMB Control Number: None. Form Number(s): NA. Type of Request: Regular submission (request for a new...

  12. An Assessment of the Spiny Lobster Panulirus homarus Fishery in ...

    African Journals Online (AJOL)

    The scalloped spiny lobster Panulirus homarus supports numerous traditional diving, trap and trammel net fisheries in the Western Indian Ocean. Commercial catches made in 2003 to 2005 in the Arabian Sea region of Oman (a coastline of ~1100 km, comprising Dhofar and. Al-Wusta) were sampled for length and sex ...

  13. Development of Powered Disk Type Sugar Cane Stubble Saver

    Directory of Open Access Journals (Sweden)

    Radite P.A.S.

    2009-04-01

    Full Text Available The objective of this research was to design, fabricate and test a prototype of sugar cane stubble saver based on powered disk mechanism. In this research, a heavy duty disk plow or disk harrow was used as a rotating knife to cut the sugarcane stubble. The parabolic disk was chosen because it is proven reliable as soil working tools and it is available in the market as spare part of disk plow or disk harrow unit. The prototype was mounted on the four wheel tractor’s three point hitch, and powered by PTO of the tractor. Two kinds of disks were used in these experiments, those were disk with regular edge or plain disk and disk with scalloped edge or scalloped disk. Both disks had diameter of 28 inch. Results of field test showed that powered disk mechanism could satisfy cut sugar cane’s stubble. However, scalloped disk type gave smoother stubble cuts compared to that of plain disk. Plain disk type gave broken stubble cut. Higher rotation (1000 rpm resulted better cuts as compared to lower rotation (500 rpm both either on plain disk and scalloped disk. The developed prototype could work below the soil surface at depth of 5 to 10 cm. With tilt angle setting 20O and disk angle 45O the width of cut was about 25 cm.

  14. Les manifestations orthopédiques de la neurofibromatose de type 1 ...

    African Journals Online (AJOL)

    L'examen neurologique montre une irritation pyramidale. Le bilan radiologique a conclu à la présence d'une scoliose double majeure de 40° en dorsale gauche et 36° en lombaire droite et un scalloping du mur postérieur, absence de lacune osseuse au niveau du crane, et pas de pseudarthrose aux membres inférieurs.

  15. 78 FR 76077 - Magnuson-Stevens Act Provisions; Fisheries of the Northeastern United States; Northeast...

    Science.gov (United States)

    2013-12-16

    ... areas were determined to have low vulnerability (Objectives 9 and 10). The exemptions granted to sector...) are periodically exposed to scallop dredging, and the overall vulnerability of bottom habitats in all.... Quotas are set using the best available science to limit fishing mortality overall so that overfishing...

  16. Treatment Outcome of Two Adjacent Implant-Supported Restorations with Different Implant Platform Designs in the Esthetic Region : A Five-Year Randomized Clinical Trial

    NARCIS (Netherlands)

    Van Nimwegen, Wouter G.; Raghoebar, Gerry M.; Stellingsma, Kees; Tymstra, Nynke; Vissink, Arjan; Meijer, Henny J. A.

    Purpose: The aim of this study was to evaluate the peri-implant soft and hard tissues and satisfaction in patients with two adjacent implant-supported restorations in the esthetic region, treated with two adjacent implants with a scalloped or flat platform. Materials and Methods: The randomized

  17. 15 CFR 922.162 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... produce a wake. Idle speed only/no-wake zone means a portion of the Sanctuary where the speed at which a..., including dead coral or rock but not individual mollusk shells (e.g., scallops, clams, oysters). Living....S. Army Corps of Engineers. No-access buffer zone means a portion of the Sanctuary where vessels are...

  18. 76 FR 42577 - Magnuson-Stevens Act Provisions; Fisheries of the Northeastern United States; Northeast...

    Science.gov (United States)

    2011-07-19

    ...) of cod, haddock, and yellowtail flounder, combined, and one Atlantic halibut per trip, without being... prohibited the possession of four species in any fishery (windowpane flounder, ocean pout, Atlantic wolffish..., and other fisheries such as the scallop fishery. The possession of Atlantic wolffish and SNE winter...

  19. 76 FR 23076 - Magnuson-Stevens Act Provisions; Fisheries of the Northeastern United States; Northeast...

    Science.gov (United States)

    2011-04-25

    ... Bank Sector. Two of the 24 sectors, the GB Cod Hook Sector and Northeast Fishery Sector I, again... caught when fishing in the Atlantic sea scallop fishery. Sector vessels fishing for monkfish, skate... for the GB Cod Fixed Gear Sector; Northeast Fishery Sectors III, VI-VIII, and X-XII; the Port Clyde...

  20. An Assessment of the Spiny Lobster Panulirus homarus Fishery in ...

    African Journals Online (AJOL)

    Abstract—The scalloped spiny lobster Panulirus homarus supports numerous traditional diving, trap and trammel net fisheries in the Western Indian Ocean. Commercial catches made in 2003 to 2005 in the Arabian Sea region of Oman (a coastline of ~1100 km, comprising Dhofar and. Al-Wusta) were sampled for length ...

  1. Size at onset of maturity of spiny lobsters Panulirus homarus ...

    African Journals Online (AJOL)

    The size at onset of sexual maturity of the scalloped spiny lobster Panulirus homarus homarus captured off Mambrui, Kenya, was estimated from ovary condition, presence of external eggs and/or spermatophore remains (berry method), and presence of well developed ovigerous setae (setal method). The predictive utility of ...

  2. The effect of the Banton 300 oil-spill accident on marine life in Umm ...

    African Journals Online (AJOL)

    ... sponges, acorn barnacles, copepods, echinoderms and fish); sub-lethal disruption of physiological and/or behavioural activities (bacterioplankton, heterotrophic flagellates, and tintinnid ciliates); effects of direct coating (birds and mangroves); incorporation of hydrocarbons in organisms (crabs, scallops, edible mussels, ...

  3. Epibiotic relationships on Zygochlamys patagonica (Mollusca, Bivalvia, Pectinidae) increase biodiversity in a submarine canyon in Argentina

    Science.gov (United States)

    Schejter, Laura; López Gappa, Juan; Bremec, Claudia Silvia

    2014-06-01

    The continental slope of the southern SW Atlantic Ocean has many distinguishable deep submarine canyons, varying in depth and extension. The benthic fauna within one of them, detected in April 2005 by means of a multibeam SIMRAD EM1002 sonar, and located at 43°35‧S to 59°33‧W, 325 m depth, was studied to discuss faunal affinities with the neighbouring Patagonian scallop fishing grounds located at upper slope depths. In order to add faunal information to the previous general study, we studied the epibiotic species settled on Patagonian scallops (the dominant species in the area) collected in the reference sampling site using a 2.5-m mouth-opening dredge, 10 mm mesh size. We sampled 103 scallops with shell heights between 22 and 69 mm; epibionts were recorded on both valves. We found 53 epibiotic taxa, which were most conspicuous on the upper valve. Bryozoa was the most diverse group (34 species) while Polychaeta was the most abundant group, recorded on 94% of the scallops. Stylasteridae (2 species) and Clavulariidae (Cnidaria) conform newly recorded epibionts on Z. patagonica and the sponge Tedania (Tedaniopsis) infundibuliformis also represents a new record for the SW Atlantic Ocean.

  4. 78 FR 40317 - Highly Migratory Species; Atlantic Shark Management Measures; Amendment 5a

    Science.gov (United States)

    2013-07-03

    ... 635 Highly Migratory Species; Atlantic Shark Management Measures; Amendment 5a; Final Rule #0;#0... Migratory Species; Atlantic Shark Management Measures; Amendment 5a AGENCY: National Marine Fisheries... rebuilding of sandbar sharks; end overfishing and rebuild scalloped hammerhead and Atlantic blacknose sharks...

  5. Cephalopods in the diets of four shark species ( galeocerdo Cuvier ...

    African Journals Online (AJOL)

    The cephalopod components of the diets of four species of shark, tiger Galeocerdo cuvier, smooth hammerhead Sphyrna zygaena, scalloped hammerhead S. lewini and great hammerhead S. mokarran, were examined to reveal patterns of prey choice. Although these sharks were caught in the inshore gillnets used in ...

  6. Sharks caught in the protective gill nets off KwaZulu-Natal, South ...

    African Journals Online (AJOL)

    Between 1978 and 1998, a total of 3 385 scalloped hammerhead sharks Sphyrna lewini was caught in the protective nets off KwaZulu-Natal. The mean annual catch was 166 sharks (range 60–279). There was a significant decrease in catch rate with time, but the relationship with the population size in KwaZulu-Natal waters ...

  7. Author Details - African Journals Online

    African Journals Online (AJOL)

    Gulak, S.J.B.. Vol 37, No 2 (2015) - Articles Hooking mortality of scalloped hammerhead Sphyrna lewini and great hammerhead Sphyrna mokarran sharks caught on bottom longlines. Abstract. ISSN: 1814-232X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors. OTHER ...

  8. Single laboratory validation of a ready-to-use phosphatase inhibition assay for detection of okadaic acid toxins.

    Science.gov (United States)

    Smienk, Henry G F; Calvo, Dolores; Razquin, Pedro; Domínguez, Elena; Mata, Luis

    2012-05-01

    A phosphatase inhibition assay for detection of okadaic acid (OA) toxins in shellfish, OkaTest, was single laboratory validated according to international recognized guidelines (AOAC, EURACHEM). Special emphasis was placed on the ruggedness of the method and stability of the components. All reagents were stable for more than 6 months and the method was highly robust under normal laboratory conditions. The limit of detection and quantification were 44 and 56 µg/kg, respectively; both below the European legal limit of 160 µg/kg. The repeatability was evaluated with 2 naturally contaminated samples. The relative standard deviation (RSD) calculated was 1.4% at a level of 276 µg/kg and 3.9% at 124 µg/kg. Intermediate precision was estimated by testing 10 different samples (mussel and scallop) on three different days and ranged between 2.4 and 9.5%. The IC(50) values of the phosphatase used in this assay were determined for OA (1.2 nM), DTX-1 (1.6 nM) and DTX-2 (1.2 nM). The accuracy of the method was estimated by recovery testing for OA (mussel, 78-101%; king scallop, 98-114%), DTX-1 (king scallop, 79-102%) and DTX-2 (king scallop, 93%). Finally, the method was qualitatively compared to the mouse bioassay and LC-MS/MS.

  9. Classification of mammographic patterns: beyond fraction of dense tissue

    Science.gov (United States)

    Judy, Philip F.; Nawfel, Richard; Jacobson, Francine L.; Smith, Darrel N.; Seltzer, Steven E.

    1999-05-01

    Women with mammograms that radiologists classify as dense have been found to have an increased risk of breast cancer. The purpose to this investigation was to determine whether human readers are willing and able to make reliable comparisons of five attributes of pairs of mammograms matched by a quantitative estimate of the fraction of dense tissue (FDT). Forty pairs of CC projections were digitized and presented using a computer workstation. The 40 pairs of mammograms had the same FDT as measured by a visual threshold procedure. Each breast image was from a different woman. The difference in the following 5 attributes were rated: (1) fraction of dense tissue, (2) fraction of homogeneous of the dense tissue, (3) fraction of ductal dense tissue, (4) prominence of scalloping of dense tissue, and (5) prominence of subareolar structures. The rating were replicated to evaluate their reliability. Spearman rank-order correlations of replicated measurements ranged from 0.89 to 0.65 (p was less than 0.0001). Homogeneous dense tissue ratings were negatively correlated with ductal dense tissue ratings (-0.59, p equals 0.0001). The prominence of scalloping rating was not significantly correlated with other attributes. The ratings of the attributes, except scalloping, were significantly correlated to differences mean gray level of breast parenchyma. Readers can make reliable judgments regarding the differences in attributes of mammograms that are matched by FDT. The negative correlation between the homogeneous dense and the ductal dense tissue ratings suggest that homogeneous dense and ductal dense tissues contend for perceived dense breast area. The absence of correlation between scalloping and other image attributes suggests further investigation of scalloping as an independent, breast-cancer risk factor is warranted.

  10. Changes in trophic flow structure of Independence Bay (Peru) over an ENSO cycle

    Science.gov (United States)

    Taylor, Marc H.; Wolff, Matthias; Mendo, Jaime; Yamashiro, Carmen

    2008-10-01

    During the strong warm El Niño (EN) that occurred in 1997/98, Independence Bay (14°S, Peru) showed a ca. 10 °C increase in surface temperatures, higher oxygen concentrations, and clearer water due to decreased phytoplankton concentrations. Under these quasi-tropical conditions, many benthic species suffered (e.g. macroalgae, portunid crabs, and polychaetes) while others benefited (e.g. scallop, sea stars, and sea urchins). The most obvious change was the strong recruitment success and subsequent proliferation of the scallop Argopecten purpuratus, whose biomass increased fiftyfold. To understand these changes, steady-state models of the bay ecosystem trophic structure were constructed and compared for a normal upwelling year (1996) and during an EN (1998), and longer-term dynamics (1996-2003) were explored based on time series of catch and biomass using Ecopath with Ecosim (EwE) software. Model inputs were based on surveys and landings data collected by the Instituto del Mar del Perú (IMARPE). Results indicate that while ecosystem size (total throughput) is reduced by 18% during EN, mainly as a result of decreased total primary production, benthic biomass remains largely unchanged despite considerable shifts in the dominant benthic taxa (e.g. scallops replace polychaetes as secondary consumers). Under normal upwelling conditions, predation by snails and crabs utilize the production of their prey almost completely, resulting in more efficient energy flow to higher trophic levels than occurs during EN. However during EN, the proliferation of the scallop A. purpuratus combined with decreased phytoplankton increased the proportion of directly utilized primary production, while exports and flows to detritus are reduced. The simulations suggest that the main cause for the scallop outburst and for the reduction in crab and macroalgae biomass was a direct temperature effect, whereas other changes are partially explained by trophic interactions. The simulations suggest

  11. Fijacion primaria y variaciones morfologicas, durante la metamorfosis de algunos bivalvos chilenos

    Directory of Open Access Journals (Sweden)

    Juan Uribe Barichivith

    1980-12-01

    Full Text Available The larval primary settlement and the changes originated during the metamorphosis of some species of Chilean bivalves, are comparatively studied, being described, the larval and post - larval stages from the veliconcha to late plantigrade. By observing in ropes "anchovetera" nets and plankton samples, in the mitiliculture of Codihué (41º 46'S; 73º 24'W, it was verified for Mytilus chilensis Hupé, 1854 and Aulacomya ater (Molina, 1782, primary settlement on the filamentous algae of genera Enteromorpha with an average size of 33º µ high, minimum average of definitive settlement, byssus positional changes, etc. Information concerning average and number of larval and post - larval attachment to different deep and inmersión period and morphological characters of larval and post - larval of: Bankia martensi Stempell, 1898 (Teredinidae, Pholas chiloensis (Molina, 1782 (Pholadidae y Chlamys patriae Doello Jurado, 1918 (Pectinidae, are also given.

  12. Chemical composition of two mineralogically contrasting Arctic bivalves' shells and their relationships to environmental variables.

    Science.gov (United States)

    Iglikowska, A; Bełdowski, J; Chełchowski, M; Chierici, M; Kędra, M; Przytarska, J; Sowa, A; Kukliński, P

    2017-01-30

    The main goal of this study was to determine the concentrations of trace elements in the mineralogically contrasting shells of two Arctic bivalves: Chlamys islandica and Ciliatocardium ciliatum. Aragonite shells seem to be more susceptible to the binding of metal ions, which is most likely a result of their crystal lattice structure. We suggest that less biologically controlled aragonite mineralization tends to incorporate more metal impurities into the crystal lattice in waters with a lower pH, where metal ions are more available. Higher concentrations of impurities may further increase the lattice distortion causing lower crystal lattice stability and higher susceptibility to dissolution. Calcitic shells seem to be less prone to bind metal ions than aragonite shells most likely because under strict biological control, the uptake of ions from ambient seawater is more selective; thus, the final crystal lattice is less contaminated by other metals and is more resistant to dissolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The subfossil occurrence of Mytilus edulis L. in central East Greenland

    DEFF Research Database (Denmark)

    Hjort, Christian; Funder, Svend Visby

    1974-01-01

    The subfossil occurrence of Mytilus edulis in central East Greenland has been CH-dated to roughly between 8000 B.P. and 5500 B.P.; compared with other areas this is a short period. Its immigration coincides with the final deglaciation of the innermost fjords, and its disappearance...... islandica can or could live, even if this was not possible along the surrounding and more hostile outer coasts. The reason for the absence of Mytilus edulis from the region today is probably not the local climate....... is contemporaneous with an increase in cold-climate plants, as shown by pollen spectra. It is suggested that it immigrated from the Svalbard area rather than from southeast Greenland. and that the central East Greenland fjord zone forms an isolated oasis, where more southerly species like Mytilus and Chlamys...

  14. Adjacent implant-supported restorations in the esthetic zone: understanding the biology.

    Science.gov (United States)

    Mitrani, Ricardo; Adolfi, Dario; Tacher, Samuel

    2005-01-01

    Traditionally, whe n considering adjacent implants in the esthetic zone, clinicians have encountered problems associated with deficient interproximal soft tissues. These discrepancies were often solved either by fabricating restorations with long interproximal contacts or by adding pink ceramics, both of which represent an esthetic compromise in today's demanding standard of care for restorative dentistry. This challenge has led to the recent introduction of scalloped implants. An understanding of the biology of wound healing of bone and soft tissue around implants and the remodeling process with implant-supported restorations allows the dental team to offer patients an alternative restorative solution consisting of combining conventional flat prosthetic table implants and scalloped implants. This article illustrates the biologic behavior of wound healing associated with dental implants and shows a step-by-step clinical case in which a patient received four adjacent implants in the esthetic zone. It also describes key elements in laboratory communication when dealing with the aforementioned restorations.

  15. Absorber for terahertz radiation management

    Science.gov (United States)

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  16. A Novel Mini-DNA Barcoding Assay to Identify Processed Fins from Internationally Protected Shark Species

    OpenAIRE

    Fields, Andrew T.; Abercrombie, Debra L.; Rowena Eng; Kevin Feldheim; Chapman, Demian D.

    2015-01-01

    There is a growing need to identify shark products in trade, in part due to the recent listing of five commercially important species on the Appendices of the Convention on International Trade in Endangered Species (CITES; porbeagle, Lamna nasus, oceanic whitetip, Carcharhinus longimanus scalloped hammerhead, Sphyrna lewini, smooth hammerhead, S. zygaena and great hammerhead S. mokarran) in addition to three species listed in the early part of this century (whale, Rhincodon typus, basking, Ce...

  17. Investigating single and multiple species fisheries management: stock status evaluation of hammerhead (Sphyrna spp.) sharks in the western North Atlantic Ocean and Gulf of Mexico.

    OpenAIRE

    Hayes, Christopher Glenn

    2007-01-01

    Three hammerhead sharks (Sphyrna spp.) are currently managed as part of the large coastal shark complex in the United States. Including multiple species in an assessment ignores the different stock dynamics of each individual species within the complex due to different life histories. This study completed individual assessments of scalloped (S. lewini), great (S. mokarran), and smooth (S. zygaena) hammerhead sharks in the U.S. Atlantic Ocean and Gulf of Mexico. Combined data for all three ...

  18. Short-Term and Long-Term Biological Effects of Chronic Chemical Contamination on Natural Populations of a Marine Bivalve.

    Science.gov (United States)

    Breitwieser, Marine; Viricel, Amélia; Graber, Marianne; Murillo, Laurence; Becquet, Vanessa; Churlaud, Carine; Fruitier-Arnaudin, Ingrid; Huet, Valérie; Lacroix, Camille; Pante, Eric; Le Floch, Stéphane; Thomas-Guyon, Hélène

    2016-01-01

    Understanding the effects of chronic chemical contamination on natural populations of marine organisms is complex due to the combined effects of different types of pollutants and environmental parameters that can modulate the physiological responses to stress. Here, we present the effects of a chronic contamination in a marine bivalve by combining multiple approaches that provide information on individual and population health. We sampled variegated scallops (Mimachlamys varia) at sites characterized by different contaminants and contamination levels to study the short and long-term (intergenerational) responses of this species to physiological stress. We used biomarkers (SOD, MDA, GST, laccase, citrate synthase and phosphatases) as indicators of oxidative stress, immune system alteration, mitochondrial respiration and general metabolism, and measured population genetic diversity at each site. In parallel, concentration of 14 trace metals and 45 organic contaminants (PAHs, PCBs, pesticides) in tissues were measured. Scallops were collected outside and during their reproductive season to investigate temporal variability in contaminant and biomarker levels. Our analyses revealed that the levels of two biomarkers (Laccase-type phenoloxidase and malondialdehyde) were significantly correlated with Cd concentration. Additionally, we observed significant seasonal differences for four of the five biomarkers, which is likely due to the scallop reproductive status at time of sampling. As a source of concern, a location that was identified as a reference site on the basis of inorganic contaminant levels presented the same level of some persistent organic pollutants (DDT and its metabolites) than more impacted sites. Finally, potential long-term effects of heavy metal contamination were observed for variegated scallops as genetic diversity was depressed in the most polluted sites.

  19. Short-Term and Long-Term Biological Effects of Chronic Chemical Contamination on Natural Populations of a Marine Bivalve.

    Directory of Open Access Journals (Sweden)

    Marine Breitwieser

    Full Text Available Understanding the effects of chronic chemical contamination on natural populations of marine organisms is complex due to the combined effects of different types of pollutants and environmental parameters that can modulate the physiological responses to stress. Here, we present the effects of a chronic contamination in a marine bivalve by combining multiple approaches that provide information on individual and population health. We sampled variegated scallops (Mimachlamys varia at sites characterized by different contaminants and contamination levels to study the short and long-term (intergenerational responses of this species to physiological stress. We used biomarkers (SOD, MDA, GST, laccase, citrate synthase and phosphatases as indicators of oxidative stress, immune system alteration, mitochondrial respiration and general metabolism, and measured population genetic diversity at each site. In parallel, concentration of 14 trace metals and 45 organic contaminants (PAHs, PCBs, pesticides in tissues were measured. Scallops were collected outside and during their reproductive season to investigate temporal variability in contaminant and biomarker levels. Our analyses revealed that the levels of two biomarkers (Laccase-type phenoloxidase and malondialdehyde were significantly correlated with Cd concentration. Additionally, we observed significant seasonal differences for four of the five biomarkers, which is likely due to the scallop reproductive status at time of sampling. As a source of concern, a location that was identified as a reference site on the basis of inorganic contaminant levels presented the same level of some persistent organic pollutants (DDT and its metabolites than more impacted sites. Finally, potential long-term effects of heavy metal contamination were observed for variegated scallops as genetic diversity was depressed in the most polluted sites.

  20. Superior mesenteric artery outcomes after fenestrated endovascular aortic aneurysm repair.

    Science.gov (United States)

    Lala, Salim; Knowles, Martyn; Timaran, David; Baig, Mirza Shadman; Valentine, James; Timaran, Carlos

    2016-09-01

    The Zenith (Cook Medical, Bloomington, Ind) fenestrated endovascular graft may be designed with single-wide scallops or large fenestrations to address the superior mesenteric artery (SMA). Misalignment of the SMA with an unstented scallop or a large fenestration is possible. This study assessed SMA outcomes after fenestrated endovascular aortic aneurysm repair (FEVAR). During an 18-month period, 47 FEVARs were performed at a single institution. For analysis, patients were grouped according to unstented (n = 23) vs stented (n = 24) SMA scallops/fenestrations. The Institutional Review Board approved this single-institution observational study. Because this was a retrospective review of the data, patient consent was unnecessary for the study. Technical success for FEVAR was 100%. The median follow-up period was 7.7 months (range, 1-16 months). Nine of 21 patients (43%) in the unstented group had some degree of misalignment of the SMA (range, 9%-71%). Among these, four patients (44%) developed complications: three SMA stenoses and one occlusion. The mean peak systolic velocity in patients with and without SMA misalignment was 317.8 cm/s vs 188.4 cm/s (P < .08), respectively. No misalignment occurred in the stented group, and only one of 19 patients (5%) developed an SMA stenosis that required angioplasty. Overall, patients with unstented SMAs had significantly more adverse events directly attributable to SMA misalignment than the stented group (44% vs 5%, respectively; P < .05). Misalignment of the SMA with the use of unstented unreinforced scallops or fenestrations occurs frequently. Routine stenting of single-wide and large fenestrations, when feasible, may be a safer option for patients undergoing FEVAR. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  1. The gingival biotype assessed by experienced and inexperienced clinicians.

    Science.gov (United States)

    Eghbali, Aryan; De Rouck, Tim; De Bruyn, Hugo; Cosyn, Jan

    2009-11-01

    A recent cluster analysis has identified three gingival biotypes among 100 periodontally healthy subjects based on different combinations of morphometric data related to maxillary front teeth and surrounding soft tissues. Patients with a thin-scalloped biotype are considered at risk because they have been associated with a compromised soft tissue response following surgical and/or restorative therapy. Hence, an accurate identification of these high-risk patients is warranted. The purpose of the present study was to evaluate the precision of simple visual inspection as a method to identify the gingival biotype by experienced and inexperienced clinicians. Fifteen clinicians (five Restorative Dentists, five Periodontists and five Students) were invited to assess the gingival biotype (thin-scalloped, thick-flat, thick-scalloped) of 100 periodontally healthy subjects based on clinical slides. Cluster analysis on these subjects was used as the gold standard and the accuracy in identifying the gingival biotype was determined using percentile agreement and kappa statistics. Intra- and inter-examiner reliability were also calculated. The gingival biotype was accurately identified only in about half of the cases irrespective of the clinician's experience. The thick-flat biotype was mostly recognized especially by experienced clinicians (> or =70% of the cases). Nearly half of the thin-scalloped cases were misclassified. The intra-examiner repeatability was fair to substantial (kappa: 0.328-0.670) and the inter-examiner reproducibility was slight to moderate (kappa: 0.127-0.547). Simple visual inspection may not be considered a valuable method to identify the gingival biotype as nearly half of the high-risk patients are overlooked.

  2. Fabrication of a Silicon Nanowire on a Bulk Substrate by Use of a Plasma Etching and Total Ionizing Dose Effects on a Gate-All-Around Field-Effect Transistor

    Science.gov (United States)

    Moon, Dong-Il; Han, Jin-Woo; Meyyappan, Meyya

    2016-01-01

    The gate all around transistor is investigated through experiment. The suspended silicon nanowire for the next generation is fabricated on bulk substrate by plasma etching method. The scallop pattern generated by Bosch process is utilized to form a floating silicon nanowire. By combining anisotropic and istropic silicon etch process, the shape of nanowire is accurately controlled. From the suspended nanowire, the gate all around transistor is demonstrated. As the silicon nanowire is fully surrounded by the gate, the device shows excellent electrostatic characteristics.

  3. Ports and Waterways Safety Assessment Workshop Report for Passamaquoddy Bay, ME

    Science.gov (United States)

    2006-10-04

    discussed. The transit route from sea to Eastport consists of passage through the Bay of Fundy to Head Harbor Passage and Friar Roads. Vessels calling...Winds Today: • Most high winds occur in the winter. • Sustained winds oppose tides from Bay of Fundy and cause high, rough seas – problem for the...Ecotourism is increasing. • Extensive fisheries throughout of the Bay : − Commercial shell fishing, lobster , quahog, scallops; and fin fish…a year- round

  4. Progress Report Abstracts. Oceanic Biology Program.

    Science.gov (United States)

    1982-12-01

    15 Cognit~ve Chauateki&cs o6 MaA~ne ManinaL R. J. Schusterman ..... .. .. ........................... 17 Ecotogica En eticA ad Deep Scatte...feeding patterns, and intra/interspecific social behaviors including aggressive interactions with humans, and (b) to develop the biotelemetry...Klimley, A.P. (in ms) Social organization of the scalloped hammerhead shark, Sphyrna lewini, in the Gulf of California Ph.D. Dissertation. UCSD (SIO

  5. Hotspots within hotspots? Hammerhead shark movements around Wolf Island, Galapagos Marine Reserve

    OpenAIRE

    Hearn, Alex; Ketchum, James; Klimley, A. Peter; Espinoza, Eduardo; Peñaherrera, Cesar

    2010-01-01

    Are pelagic species such as sharks and tuna distributed homogenously or heterogeneously in the oceans? Large assemblages of these species have been observed at seamounts and offshore islands in the eastern tropical Pacific, which are considered hotspots of pelagic biodiversity. Is the species distribution uniform at these hotspots or do species aggregate at a finer spatial scale at these sites? We employed three techniques to demonstrate that the aggregations of scalloped hammerhead sharks, S...

  6. A Guide for Using Geochemical Methods in Dredged Material, Sediment Tracking, and Sediment Budget Studies

    Science.gov (United States)

    2017-06-26

    Larkin. 2000. Effect of drawdown on ammonium and iron concentrations in a coastal mountain reservoir. Water Quality Research Journal of Canada 35(2...Entrainment, dispersal and settlement of scallop dredge sediment plumes: Field measurements and numerical modeling. Canadian Journal of Fish and Aquatic...Selecting fingerprint properties for discriminating potential suspended sediment sources in river basins. Journal of Hydrology 261(1): 218–244. Countway

  7. Archeological Test Excavations at The Lake Acworth Site (9Co45) and The Butler Creek (9Co46) Sites: Two Prehistric Settlements in the Piedmont Uplands, Allatoona Lake, Cobb County, Georgia

    Science.gov (United States)

    1991-10-31

    12). Cross-sections perpendicular to the medial axes of the more complete specimens ranged from bi-convex to plano -convex, the latter shape being the...are characterized by heavy, much cruder designs and applications and the diagnostic " pie crust" or scalloped rim is absent. Notched rims are present...shape is a plano -convex discoid in which the planer surface is used as a striking platform to produce flake blanks. TABLE 35. Core Data, 9Co45.* Ba

  8. MRI of cauda equina syndrome in ankylosing spondylitis: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Yang; Choi, Pil Yeob; Sung, Young Soon; Kwon, Jae Soo [Masan Samsung General Hospital, Masan (Korea, Republic of)

    1995-10-15

    Cauda equina syndrome is a rare neurologic complication in patient with long-standing ankylosing spondylitis. Authors report a case of cauda equina syndrome in ankylosing spondylitis. On plain radiographs, typical 'bamboo spine' and fusion of sacroiliac joints were noted. MRI of the lumbar spine revealed arachnoid diverticulae which were isointense to cerebrospinal fluid on all spin echo sequences, and showed bony erosion and scalloping of posterior arches.

  9. Induction de la métamorphose de la coquille Saint-Jacques Pecten maximus L. par des dérives de la tyrosine extraits de l'algue Delesseria sanguinea Lamouroux ou synthétiques

    OpenAIRE

    Cochard, Jean-claude; Chevolot, L.; Yvin, J.c.; Chevolot-magueur, A. M.

    1987-01-01

    King scallop Pecten maximus L. larvae reared in stagnant sea water generally show a delayed metamorphosis. These larvae do not seem to look for a specific fixation substrate, but introduced Delesseria sanguinea Lamouroux aqueous extracts bring about a significant rise in the metamorphosis rates and the mortalities according to the concentration of extracts in the water. A series of experiments enabled the identification of the inducing agent of Delesseria sanguinea extracts: jacaranone. This ...

  10. Short Rayleigh Range Free Electron Laser Amplifiers

    CERN Document Server

    Yu, L H; Murphy, J B; Rose, J; Shaftan, T V; Wang, X J; Watanabe, T

    2005-01-01

    An important requirement for a high average power laser system is a manageable power density on the first optical element. One possibility to achieve this is a single pass amplifier which generates a short Rayleigh range (SRL) light beam. We present design parameters and calculated performances for several SRL configurations. These include a simulation of the optically guided (pinched) MW class FEL [1], the scalloped beam FEL amplifier [2] and high gain TOK amplifiers we propose to explore at our SDL facility.

  11. Christmas feast in Prévessin

    CERN Multimedia

    2000-01-01

    Restaurant No3 was invaded by a happy bunch of Santa Clauses last Wednesday. It has become a tradition for the restaurant staff to dress up to serve a real Christmas feast. In the menu : Foie gras des Landes, scallops, salmon tartar and of course the traditional Christmas turkey. And a special extra - an aperitif graciously offered by the restaurant. Places were laid for 450 people for this exceptional lunch.

  12. What Is a Hill? An Analysis of the Meanings of Generic Topographic Terms

    Science.gov (United States)

    1985-08-01

    scrabbled surface implies alkaline daposits can include bech ridges few drainage features no vegetation, unless scattered scrub irrigation and intense...concentric, crescent-shaPed (dunes), hook-shaped, hummocky, intersectingt scrabbled , snake-likes star-shaped (dunes), and save-shaped. In this...sawtooth ridges 5 (193) scalloped bases I dunes I hills 4 rocks 1 slopes 3 (194) scattered buttes I forests 4 e sas 1 orchards 1 plateaus 1 (195) scrabbled

  13. Volcan Reventador's Unusual Umbrella

    Science.gov (United States)

    Chakraborty, P.; Gioia, G.; Kieffer, S. W.

    2005-12-01

    In the past two decades, field observations of the deposits of volcanoes have been supplemented by systemmatic, and sometimes, opportunistic photographic documentation. Two photographs of the umbrella of the December 3, 2002 eruption of Volcan Reventador, Ecuador, reveal a prominently scalloped umbrella that is unlike any umbrella previously documented on a volcanic column. The material in the umbrella was being swept off a descending pyroclastic flow, and was, therefore, a co-ignimbrite cloud. We propose that the scallops are the result of a turbulent Rayleigh-Taylor (RT) instability with no precedents in volcanology. We ascribe the rare loss of buoyancy that drives this instability to the fact that the Reventador column fed on a cool co-ignimbrite cloud. On the basis of the observed wavelength of the scallops, we estimate a value for the eddy viscosity of the umbrella of 4000 ~m2/s. This value is consistent with a previously obtained lower bound (200 ~m2/s, K. Wohletz, priv. comm., 2005). We do not know the fate of the material in the umbrella subsequent to the photos. The analysis suggests that the umbrella was negatively buoyant. Field work on the co-ignimbrite deposits might reveal whether or not the material reimpacted, and if so, where and whether or not this material was involved in the hazardous flows that affected the main oil pipeline across Ecuador.

  14. Radiologic findings of adult pelvis and appendicular skeletal Langerhans cell histiocytosis in nine patients

    Energy Technology Data Exchange (ETDEWEB)

    Song, You Seon; Lee, In Sook; Kim, Do Kyung [Pusan National University Hospital, Medical Research Institute, Department of Radiology, Busan (Korea, Republic of); Pusan National University, School of Medicine, Department of Radiology, Busan (Korea, Republic of); Yi, Jae Hyuck [Kyungpook National University Hospital, Department of Radiology, Daegu (Korea, Republic of); Cho, Kil Ho [Yeungnam University College of Medicine, Department of Radiology, Daegu (Korea, Republic of); Song, Jong Woon [Inje University Haeundae Paik Hospital, Department of Radiology, Busan (Korea, Republic of)

    2011-11-15

    The purpose of this article was to evaluate the radiologic findings of adult pelvis and appendicular skeletal Langerhans cell histiocytosis (LCH), emphasizing the CT and MR findings. The images of nine patients with pathologically proven LCH (five men and four women; mean age, 37.11 years) were retrospectively reviewed. Imaging analysis was confined to the long and flat bones. CT scans were performed in five patients and MR imaging was performed in eight. Images were assessed for the following features on CT and MRI: the location and number of lesions; the presence of cortical destruction, endosteal scalloping, and a periosteal reaction on CT or MRI; the margin of soft tissue masses, the presence of bone marrow edema, and a ''budding'' appearance on MRI; and the presence of sclerotic margins or septations on CT. The involved skeletal sites were the pelvis (seven), femurs (five), humeri (two), tibias (two), fibula (one), clavicle (one), scapula (one), and sternum (one). Endosteal scalloping, a periosteal reaction, and a budding appearance were common on MRI or CT images. Although cortical destruction and the soft tissue lesion formation were rare, soft tissue masses had well-defined margins. Endosteal scalloping and a budding appearance with a periosteal reaction on CT and MRI may be helpful signs for differentiation of LCH from malignant tumors in adults. (orig.)

  15. Stability of molybdenum nanoparticles in Sn-3.8Ag-0.7Cu solder during multiple reflow and their influence on interfacial intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Arafat, M.M., E-mail: arafat_mahmood@yahoo.com; Johan, Mohd Rafie, E-mail: mrafiej@um.edu.my

    2012-02-15

    This work investigates the effects of molybdenum nanoparticles on the growth of interfacial intermetallic compound between Sn-3.8Ag-0.7Cu solder and copper substrate during multiple reflow. Molybdenum nanoparticles were mixed with Sn-3.8Ag-0.7Cu solder paste by manual mixing. Solder samples were reflowed on a copper substrate in a 250 Degree-Sign C reflow oven up to six times. The molybdenum content of the bulk solder was determined by inductive coupled plasma-optical emission spectrometry. It is found that upon the addition of molybdenum nanoparticles to Sn-3.8Ag-0.7Cu solder, the interfacial intermetallic compound thickness and scallop diameter decreases under all reflow conditions. Molybdenum nanoparticles do not appear to dissolve or react with the solder. They tend to adsorb preferentially at the interface between solder and the intermetallic compound scallops. It is suggested that molybdenum nanoparticles impart their influence on the interfacial intermetallic compound as discrete particles. The intact, discrete nanoparticles, by absorbing preferentially at the interface, hinder the diffusion flux of the substrate and thereby suppress the intermetallic compound growth. - Highlights: Black-Right-Pointing-Pointer Mo nanoparticles do not dissolve or react with the SAC solder during reflow. Black-Right-Pointing-Pointer Addition of Mo nanoparticles results smaller IMC thickness and scallop diameter. Black-Right-Pointing-Pointer Mo nanoparticles influence the interfacial IMC through discrete particle effect.

  16. Cardiac hypertrophy induced by active Raf depends on Yorkie-mediated transcription.

    Science.gov (United States)

    Yu, Lin; Daniels, Joseph P; Wu, Huihui; Wolf, Matthew J

    2015-02-03

    Organ hypertrophy can result from enlargement of individual cells or from cell proliferation or both. Activating mutations in the serine-threonine kinase Raf cause cardiac hypertrophy and contribute to Noonan syndrome in humans. Cardiac-specific expression of activated Raf also causes hypertrophy in Drosophila melanogaster. We found that Yorkie (Yki), a transcriptional coactivator in the Hippo pathway that regulates organ size, is required for Raf-induced cardiac hypertrophy in flies. Although aberrant activation of Yki orthologs stimulates cardiac hyperplasia in mice, cardiac-specific expression of an activated mutant form of Yki in fruit flies caused cardiac hypertrophy without hyperplasia. Knockdown of Yki caused cardiac dilation without loss of cardiomyocytes and prevented Raf-induced cardiac hypertrophy. In flies, Yki-induced cardiac hypertrophy required the TEA domain-containing transcription factor Scalloped, and, in mammalian cells, expression of mouse Raf(L613V), an activated form of Raf with a Noonan syndrome mutation, increased Yki-induced Scalloped activity. Furthermore, overexpression of Tgi (a Tondu domain-containing Scalloped-binding corepressor) in the fly heart abrogated Yki- or Raf-induced cardiac hypertrophy. Thus, crosstalk between Raf and Yki occurs in the heart and can influence Raf-mediated cardiac hypertrophy. Copyright © 2015, American Association for the Advancement of Science.

  17. ANALISIS RESIKO KESEHATAN PENCEMARAN LOGAM BERAT PADA AIR, SEDIMEN, DAN SIMPING (Placuna placenta DI PESISIR KABUPATEN TANGERANG

    Directory of Open Access Journals (Sweden)

    Anna Rejeki Simbolon

    2014-07-01

    Full Text Available Waste containing heavy metals originating from human activity in Tangerang will go into the waters and tributaries of the Coastal District Tangerang. Heavy metals accumulate in bodies of water, sediment and biota scallop will go into the human body through exposure to direct dermal contact or intake. The purpose of this study to determine the public health risk due to exposure to heavy metals and formulate risk management that can be done. The approach taken by the USEPA methods of risk analysis and quantification of health risks from exposure to water and sediment using SEDISOIL risk analysis model developed by the National Institute of Public Health and Environmental Protection.. The results showed that in general water quality parameters are still below the quality standard by decree No. 51 of 2004 LH. Analysis of health risks for people who move directly (bathing, swimming, fishing shows the value of RQ > 1, meaning that coastal communities at risk for adverse effects of exposure to heavy metals Pb, Cd and Zn. Similarly, the results of the analysis of risk through consumption of biota scallop, with RQ values > 1 and ECR > 10-4. It shows that scallop (Placuna placenta is not suitable for consumption by the public, because the content of Pd , Cd, and Zn health risk for consuming.Keywords: risk assessment, heavy metals, Tangerang District littoral

  18. Bioaccessibility of essential and non-essential metals in commercial shellfish from Western Europe and Asia.

    Science.gov (United States)

    Amiard, Jean-Claude; Amiard-Triquet, Claude; Charbonnier, Laetitia; Mesnil, Aurélie; Rainbow, Philip S; Wang, Wen-Xiong

    2008-06-01

    Maximum acceptable concentrations of metals in food - based on total concentrations - have been established in many countries. To improve risk assessment, it would be better to take into account bioaccessible concentrations. A total of seven species of molluscs from France, UK and Hong Kong was examined in this study including clams, mussels, oysters, scallops and gastropods. The species which have total metal concentrations higher than the most severe food security limits are mainly oysters (all of the three studied species), the gastropod Buccinum undatum for cadmium and zinc, and scallops for cadmium. The lowest bioaccessibility (in % extractability with gut juices) was observed for silver (median for all of the species: 14%), it was moderate for lead (median: 33%) and higher for cadmium, zinc and copper (medians were respectively 54%, 65%, and 70%). In most cases, bioaccessible concentrations remained higher than the safety limits, except for cadmium in scallops and zinc in B. undatum. The influence of feeding habit (masticated or swallowed, addition of vinegar or lemon) on metal bioaccessibility in oysters is limited. On the contrary, cooking the gastropods decreased the bioaccessibility of metals, except silver.

  19. Artificial substrates preference for proliferation and immigration in Aurelia aurita (s. l.) polyps

    Science.gov (United States)

    Feng, Song; Lin, Jianing; Sun, Song; Zhang, Fang

    2017-01-01

    The increasing amounts of artificial marine substrates, in many parts of the world have been proposed as a potential driver of Aurelia spp. blooms, on account of providing extra habitats for the settlement and the proliferation of the benthic stage (polyps). Previous experiments have mainly focused on the substrate choices of Aurelia spp. planulae. However, substrate preferences for the proliferation and immigration of polyps have not been reported. We monitored the propagation and immigration of Aurelia aurita (s. l.) polyps on two natural and nine artificial substrates at constant temperature (20±0.5°C) and salinity (30±0.5) in beakers and a glass aquarium in the laboratory, respectively. The results showed that, among artificial substrates, the highest number for polyp proliferation and immigration was found on nets, rigid polyvinyl chloride plates (RPVC), and wood. The lowest density of polyps was present on iron plates. Among natural substrates, the asexual reproduction rate of polyps on Patinopecten yessoensis (Jay, 1857) shells was significantly higher than Azumapecten farreri (Jones & Preston, 1904). On the account of the distinction in the roughness, chemical properties and biofilms of these material surfaces, bare artificial or natural substrates discriminatively affect the proliferation and the immigration of Aurelia spp. polyps at laboratory. These observations suggest that, even in the natural environment, different materials and texture may influence the composition and the abundance of the fouling communities and the assemblages of polyps and, indirectly, have effects on the amounts of released medusae.

  20. Identification and characterization of a LTR retrotransposon from the genome of Cyprinus carpio var. Jian.

    Science.gov (United States)

    Cao, Liping; Yin, Guojun; Cao, Zheming; Bing, Xuwen; Ding, Weidong

    2016-06-01

    A Ty3/gypsy-retrotransposon-type transposon was found in the genome of the Jian carp (Cyprinus carpio var. Jian) in a previous study (unpublished), and was designated a JRE retrotransposon (Jian retrotransposon). The full-length JRE retrotransposon is 5126 bp, which includes two long terminal repeats of 470 bp at the 5' end and 453 bp at the 3' end, and two open reading frames between them: 4203 bp encoding the group-specific antigen (GAG) and polyprotein (POL). The pol gene has a typical Ty3/gypsy retrotransposon structure, and the gene order is protease, reverse transcriptase, RNase H, and integrase (PR-RT-RH-IN). A phylogenetic analysis of the pol gene showed that it has similarities of 40.7, 40, and 32.8 %, to retrotransposons of Azumapecten farreri, Mizuhopecten yessoensis, and Xiphophorus maculatus, respectively. Therefore, JRE might belong to the JULE retrotransposon family. The copy number of the JRE transposon in the genome of the Jian carp is 124, determined with real-time quantitative PCR. The mRNA of the JRE retrotransposon is expressed in five Jian carp tissues, the liver, kidney, blood, muscle, and gonad, and slightly higher in the kidney and liver than in the other tissues.

  1. The presence of Plio-Pleistocene Paleolama sp. (Artiodactyla: camelidae of the southern coast of Peru

    Directory of Open Access Journals (Sweden)

    2003-01-01

    Full Text Available Nous présentons un spécimen du genre Palaeolama qui correspond au registre le plus ancien du genre sur le territoire péruvien ainsi que l’un des plus anciens en Amérique du Sud. La morphologie et la taille des éléments découverts sont comparables aux formes sudaméricaines P. (Hemiauchenia paradoxa ainsi qu’aux formes les plus petites de P. (Palaeolama weddellii. Ce spécimen provient des dépôts marins littoraux d’Atiquipa (côte sud-péruvienne. La présence du mollusque bivalve Chlamys vidali à la base de la section ainsi que de faluns coquilliers actuels, présents au niveau des terrasses marines les plus hautes qui terminent la section, correspondrait à un âge de 2 millions d’années. Cette date est légèrement supérieure ou égale aux registres les plus anciens de P. (Palaeolama en Amérique du Nord. Cette découverte confirme que les Lamini étaient présents dans les écosystèmes andins avant l’Holocène Se presenta el registro más antiguo del género Palaeolama en el territorio peruano y uno de los más antiguos de Sudamérica. La forma y tamaño del material conservado es comparable con las formas sudamericanas P. (Hemiauchenia paradoxa y los especímenes más pequeños de P. (Palaeolama weddellii. Procede de los depósitos marinos litorales innominados de Atiquipa, en la costa sur del Perú. La ocurrencia del molusco bivalvo extinto Chlamys vidali en la base de la sección y la coquina de moluscos actuales presentes en la terraza marina más alta que termina dicha sección, indicaría una edad aproximada de 2 millones de años. Esta edad es ligeramente mayor o igual a los registros más antiguos de P. (Palaeolama en Norteamérica. El presente reporte confirma que los Lamini no fueron ajenos a los ecosistemas andinos antes del Holoceno. We report the oldest record of the genus Palaeolama in Peru its constitutes one of the oldest records for the genus in South America. The shape and size of the fossil material is

  2. Enhanced visual fields in hammerhead sharks.

    Science.gov (United States)

    McComb, D M; Tricas, T C; Kajiura, S M

    2009-12-01

    Several factors that influence the evolution of the unusual head morphology of hammerhead sharks (family Sphyrnidae) are proposed but few are empirically tested. In this study we tested the 'enhanced binocular field' hypothesis (that proposes enhanced frontal binocularity) by comparison of the visual fields of three hammerhead species: the bonnethead shark, Sphyrna tiburo, the scalloped hammerhead shark, Sphyrna lewini, and the winghead shark, Eusphyra blochii, with that of two carcharhinid species: the lemon shark, Negaprion brevirostris, and the blacknose shark, Carcharhinus acronotus. Additionally, eye rotation and head yaw were quantified to determine if species compensate for large blind areas anterior to the head. The winghead shark possessed the largest anterior binocular overlap (48 deg.) and was nearly four times larger than that of the lemon (10 deg.) and blacknose (11 deg.) sharks. The binocular overlap in the scalloped hammerhead sharks (34 deg.) was greater than the bonnethead sharks (13 deg.) and carcharhinid species; however, the bonnethead shark did not differ from the carcharhinids. These results indicate that binocular overlap has increased with lateral head expansion in hammerhead sharks. The hammerhead species did not demonstrate greater eye rotation in the anterior or posterior direction. However, both the scalloped hammerhead and bonnethead sharks exhibited greater head yaw during swimming (16.9 deg. and 15.6 deg., respectively) than the lemon (15.1 deg.) and blacknose (15.0 deg.) sharks, indicating a behavioral compensation for the anterior blind area. This study illustrates the larger binocular overlap in hammerhead species relative to their carcharhinid sister taxa and is consistent with the 'enhanced binocular field' hypothesis.

  3. Immediate nonfunctional loading of NobelPerfect implants in the anterior dental arch in private practice--5-year data.

    Science.gov (United States)

    Noelken, Robert; Kunkel, Martin; Jung, Britta A; Wagner, Wilfried

    2014-02-01

    The concept of scalloped implants to maintain the natural contour of the alveolar ridge has been a source of controversy for many years. This study examined the long-term clinical performance of the scalloped NobelPerfect implant in a one-stage procedure (immediate loading in the esthetic zone). In 20 patients, immediate prosthetic restorations were placed on 31 NobelPerfect implants in a private practice and followed for up to 78 months. Twenty-one implants were placed immediately after extraction, seven implants were placed after osseous consolidation of the extraction sockets, and three implants were placed secondary to extended alveolar ridge augmentation procedures. All implants were provisionalized on the day of implant placement and adjusted to clear all contacts in centric occlusion and during eccentric movements. Outcome variables were success rates, marginal bone levels, and pink esthetic score (PES) assessed per implant. One implant failed after 1.4 months. Five patients with six implants in total were scored in the 5-year follow-up as dropouts. Mean follow-up period of remaining 24 implants was 65 months (range, 55-78 months). Cumulative success rates according to the criteria specified by Smith and Zarb were 96.8%. Marginal bone levels averaged 1.1 mm above the first thread. Mean PES ratings were 10.5 (range, 3-13). Survival rates, marginal bone levels, and esthetic results suggest proof of principle for the preservation of the interproximal bony lamella with a scalloped implant design in long-term data. © 2012 Wiley Periodicals, Inc.

  4. Utilization of a Porous Cu Interlayer for the Enhancement of Pb-Free Sn-3.0Ag-0.5Cu Solder Joint

    Directory of Open Access Journals (Sweden)

    Nashrah Hani Jamadon

    2016-09-01

    Full Text Available The joining of lead-free Sn-3.0Ag-0.5Cu (SAC305 solder alloy to metal substrate with the addition of a porous Cu interlayer was investigated. Two types of porous Cu interlayers, namely 15 ppi—pore per inch (P15 and 25 ppi (P25 were sandwiched in between SAC305/Cu substrate. The soldering process was carried out at soldering time of 60, 180, and 300 s at three temperature levels of 267, 287, and 307 °C. The joint strength was evaluated by tensile testing. The highest strength for solder joints with addition of P25 and P15 porous Cu was 51 MPa (at 180 s and 307 °C and 54 MPa (at 300 s and 307 °C , respectively. The fractography of the solder joint was analyzed by optical microscope (OM and scanning electron microscopy (SEM. The results showed that the propagation of fracture during tensile tests for solder with a porous Cu interlayer occurred in three regions: (i SAC305/Cu interface; (ii inside SAC305 solder alloy; and (iii inside porous Cu. Energy dispersive X-ray spectroscopy (EDX was used to identify intermetallic phases. Cu6Sn5 phase with scallop-liked morphology was observed at the interface of the SAC305/Cu substrate. In contrast, the scallop-liked intermetallic phase together with more uniform but a less defined scallop-liked phase was observed at the interface of porous Cu and solder alloy.

  5. Recruitment patterns of Serpula vermicularis L. (Polychaeta, Serpulidae) in Loch Creran, Scotland

    Science.gov (United States)

    Chapman, Nicola D.; Moore, Colin G.; Harries, Dan B.; Lyndon, Alastair R.

    2007-07-01

    This study aimed to contribute to conservation management of reefs of Serpula vermicularis by increasing understanding of the factors influencing larval settlement. The study was carried out in Loch Creran, which supports the most extensive known development of S. vermicularis reefs in the world. Settlement plates were deployed to examine the influence of season, depth, reef density, substrate type and orientation. Monthly deployment of plates revealed settlement of S. vermicularis to occur predominantly from mid-June to mid-October, peaking in late August to early September. Settlement of Pomatoceros spp. peaked much earlier, in late May to early June. Deployment of plates at different depths revealed a marked reduction in S. vermicularis settlement intensity between 6 and 12 m. As this corresponds with the deeper limit of the peripheral fringe of serpulid reefs in the loch, it is suggested that this limit is imposed by a depth-correlated settlement response, rather than reduction in available substrata. Comparisons of various substrata showed a preference by S. vermicularis larvae for a slate over a scallop substrate and no evidence of enhanced recruitment to occupied or unoccupied tubes of S. vermicularis, suggesting that gregarious attraction is unlikely to be a factor causing reef formation. Settlement onto the upper side of a horizontal scallop substrate was found to be insignificant in comparison with the underside or a vertically orientated scallop. Evidence for the role of light in controlling the depth and substrate-orientation preferences of S. vermicularis larvae is discussed. Based on the results of this study, recommendations are made regarding remediation of areas suffering reef damage.

  6. Trophic and environmental drivers of the Sechura Bay Ecosystem (Peru) over an ENSO cycle

    Science.gov (United States)

    Taylor, Marc H.; Wolff, Matthias; Vadas, Flora; Yamashiro, Carmen

    2008-03-01

    Interannual environmental variability in Peru is dominated by the El Niño Southern Oscillation (ENSO). The most dramatic changes are associated with the warm El Niño (EN) phase (opposite the cold La Niña phase), which disrupts the normal coastal upwelling and affects the dynamics of many coastal marine and terrestrial resources. This study presents a trophic model for Sechura Bay, located at the northern extension of the Peruvian upwelling system, where ENSO-induced environmental variability is most extreme. Using an initial steady-state model for the year 1996, we explore the dynamics of the ecosystem through the year 2003 (including the strong EN of 1997/98 and the weaker EN of 2002/03). Based on support from literature, we force biomass of several non-trophically-mediated ‘drivers’ (e.g. Scallops, Benthic detritivores, Octopus, and Littoral fish) to observe whether the fit between historical and simulated changes (by the trophic model) is improved. The results indicate that the Sechura Bay Ecosystem is a relatively inefficient system from a community energetics point of view, likely due to the periodic perturbations of ENSO. A combination of high system productivity and low trophic level target species of invertebrates (i.e. scallops) and fish (i.e. anchoveta) results in high catches and an efficient fishery. The importance of environmental drivers is suggested, given the relatively small improvements in the fit of the simulation with the addition of trophic drivers on remaining functional groups’ dynamics. An additional multivariate regression model is presented for the scallop Argopecten purpuratus, which demonstrates a significant correlation between both spawning stock size and riverine discharge-mediated mortality on catch levels. These results are discussed in the context of the appropriateness of trophodynamic modeling in relatively open systems, and how management strategies may be focused given the highly environmentally influenced marine

  7. Arsenic speciation in fish and shellfish from the North Sea (Southern bight) and Açu Port area (Brazil) and health risks related to seafood consumption.

    Science.gov (United States)

    Gao, Yue; Baisch, Paulo; Mirlean, Nicolai; Rodrigues da Silva Júnior, Flavio Manoel; Van Larebeke, Nik; Baeyens, Willy; Leermakers, Martine

    2018-01-01

    In North Sea and Port Açu (Brazil) coastal areas, high arsenic (As) concentrations were observed in water, soil and sediments. Therefore, the impact of this contamination on fish and shellfish species bought from local fishermen was studied. Total As was assessed with ICP-OES (Brazil) and ICP-MS (North Sea) after microwave digestion. Toxic As was assessed with liquid chromatography-ICP-MS (Brazil) and hydride generation-atomic fluorescence spectrometry (North Sea). All analytical methods comply with Quality Assurance/Quality Control procedures. Several fish species have average Total As concentrations above 1 μg g-1 wet weight (ww), but the highest concentrations are found in less spotted dogfish, lemon sole and whelks from the North Sea, with respectively 50, 49 and 50 μg g-1 ww. High Total As concentrations correspond to high Toxic As concentrations, except for scallops having increased Toxic As concentrations. Toxic As fractions are highest in scallops (almost 10%) but rarely exceeds 2% in all other species. Liver samples were only analyzed in ray, dogfish and catfish and their Toxic As fractions are between 2 and 4 times higher than in muscle. For a consumption of 150 g of seafood, only 3 samples exceed the provisional total daily intake of 2 μg kg-1 bw, however, cancer risks are non-negligible. Using mean Toxic As concentrations for each of the different fish and shellfish species studied, Lifetime Cancer Risk values at the actual global seafood consumption rate of 54 g day-1 are above 10-4 for whelks, scallops, dogfish, ray and lemon sole. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. MRI and clinical features of Langerhans cell histiocytosis (LCH) in the pelvis and extremities: can LCH really look like anything?

    Energy Technology Data Exchange (ETDEWEB)

    Samet, Jonathan [Northwestern University Feinberg School of Medicine, Department of Medical Imaging, Ann and Robert H. Lurie Children' s Hospital of Chicago, Chicago, IL (United States); Weinstein, Joanna [Northwestern University Feinberg School of Medicine, Departments of Pediatrics, Division of Hematology/Oncology/Stem Cell Transplant, Ann and Robert H. Lurie Children' s Hospital of Chicago, Chicago, IL (United States); Fayad, Laura M. [The Johns Hopkins University School of Medicine, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States)

    2016-05-15

    To assess clinical and MRI features of Langerhans cell histiocytosis in the pelvis and extremities. The MRI and clinical features of 21 pathologically proven cases of LCH involving the pelvis and extremities were studied. Multiple characteristics of the lesions were evaluated (location, size, T1/ T2/post-contrast features, perilesional bone and soft tissue signal, endosteal scalloping, periosteal reaction, soft tissue mass, pathologic fracture). Pre-biopsy radiologic diagnoses were collected from the original clinical reports. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), temperature, and white blood cell count (WBC) were collected at the time of diagnosis when available. The locations of the LCH lesions included five humerus, four femur, five ilium, one tibia, one clavicle, and three scapula. Lesional size ranged from 1.8 to 7.1 cm, with a mean of 3.6 cm. All lesions demonstrated perilesional bone marrow edema, periosteal reaction, endosteal scalloping, and post-contrast enhancement. An associated soft tissue mass was present in 15/21 (71.4 %). Clinically, the WBC, ESR, and CRP were elevated in 2/14 (14 %), 8/12 (67 %), and 4/10 (40 %) of cases, respectively. Fever was documented in 1/15 (7 %) patients and pain was reported in 15/15 (100 %). The clinical and radiologic features of LCH in the pelvis and extremities overlap with infection and malignancy, but LCH must be considered in the differential diagnosis, as it routinely presents with aggressive MRI features, including endosteal scalloping, periosteal reaction, perilesional edema, and a soft tissue mass. Furthermore, an unknown skeletal lesion at presentation without aggressive MRI features is unlikely to represent LCH. (orig.)

  9. Structural changes in odontodysplasia.

    Science.gov (United States)

    Lustmann, J; Ulmansky, M

    1976-02-01

    Report is made of a histologic and scanning electron microscopic (SEM) study of teeth affected by odontodysplasia. The enamel was found to be thinner than normal, and the entire surface showed numerous depressions. The prismatic orientation, diameter, and density were found to be normal. Although the mantle dentin remained normal, the rest of this tissue showed a tendency to globular formation. The orientation, density, size, and shape of the dentinal tubules appeared to be normal. The cementum, in general, was normal, but in some instances appeared to be scalloped or globular. The pulp consisted of normal tissue but was found to be larger than normal. The presence of denticles was an outstanding feature.

  10. Collapse and conservation of shark populations in the Northwest Atlantic.

    Science.gov (United States)

    Baum, Julia K; Myers, Ransom A; Kehler, Daniel G; Worm, Boris; Harley, Shelton J; Doherty, Penny A

    2003-01-17

    Overexploitation threatens the future of many large vertebrates. In the ocean, tunas and sea turtles are current conservation concerns because of this intense pressure. The status of most shark species, in contrast, remains uncertain. Using the largest data set in the Northwest Atlantic, we show rapid large declines in large coastal and oceanic shark populations. Scalloped hammerhead, white, and thresher sharks are each estimated to have declined by over 75% in the past 15 years. Closed-area models highlight priority areas for shark conservation, and the need to consider effort reallocation and site selection if marine reserves are to benefit multiple threatened species.

  11. Mother-offspring isotope fractionation in two species of placentatrophic sharks.

    Science.gov (United States)

    Vaudo, J J; Matich, P; Heithaus, M R

    2010-11-01

    Stable-isotope values of a scalloped hammerhead Sphyrna lewini and blacktip shark Carcharhinus limbatus and their respective embryos were analysed. Embryos of both species were enriched in δ(15) N compared to their mothers (0·82 and 0·88‰, respectively), but fractionation of δ(13) C varied. Embryonic S. lewini were enriched (1·00‰) in δ(13) C while C. limbatus were depleted (0·27‰) relative to their mothers. © 2010 The Authors. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

  12. Identification of young-of-the-year great hammerhead shark Sphyrna mokarran in northern Florida and South Carolina.

    Science.gov (United States)

    Barker, A M; Frazier, B S; Bethea, D M; Gold, J R; Portnoy, D S

    2017-08-01

    Two sharks, visually identified in the field as young-of-the-year (YOY) scalloped hammerhead Sphyrna lewini, were identified as great hammerhead Sphyrna mokarran based on nuclear-encoded single nucleotide polymorphisms (SNP) and sequences of mtDNA. Individuals were captured and released in Bulls Bay, SC, and Saint Joseph Bay, FL, in 2013 and 2014, respectively. These findings indicate S. mokarran may be pupping in or around these areas and highlight new regions that may be a productive focus for future research on early life history of S. mokarran. © 2017 The Fisheries Society of the British Isles.

  13. ラットにおける天然物由来カルシウム素材の利用効率

    OpenAIRE

    志塚, ふじ子

    2011-01-01

    Bioavailability of four organic calcium (Ca) products (egg shell, fish bone, scallop shell, and dolomite) was evaluated by comparing with that of Ca-carbonate used as control Ca. Eight-week-old female rats were divided into eleven groups of a Ca-free diet and ten low Ca diets: 0.1% Ca diets with four Ca products and control Ca, 0.25% Ca diets of the same Ca sources as 0.1% Ca diets. Animals were fed each diet for two weeks. No significant differences in food intake and body weight gain were o...

  14. A System for the Preference Evaluation of Cycle Menus

    Science.gov (United States)

    1974-10-01

    51 .98 5.12 57 Hamburger 5.76 1.77 -.34 .99 8.01 58 Lasagna 4.27 2.11 -.48 .99 6.47 59 Pizza (1 ! 5.0^ 2.16 -.44 .99 7.53 60 Pizza (’.) 5.02 2.23...6.60 Pickled Beet & Onion Salad 1.73 .46 -.08 .99 2.26 Pineapple Cheese Salad 3.19 1.23 -.24 .9C 4.63 Tossed Cucumber & Vegetable Salad (1) 4.30...French Fried Onion Rings, Jellied Banana Salad, Apricot Pie 22. Fish Sticks, Scalloped Potatoes, Succotash (Lima Beans + Corn), Pineapple Cheese Salad

  15. An introduction to the hydrodynamics of swimming microorganisms

    Science.gov (United States)

    Yeomans, J. M.; Pushkin, D. O.; Shum, H.

    2014-09-01

    This manuscript is a summary of a set of lectures given at the Geilo School 2013 Soft Matter Confinement: from Biology to Physics. It aims to provide an introduction to the hydrodynamics that underlies the way in which microorganisms, such as bacteria and algae, and fabricated microswimmers, swim. We focus on two features peculiar to bacterial swimming: the Scallop theorem and the dipolar nature of the far flow field. We discuss the consequences of these to the velocity field of a swimmer suspension and to the motion of passive tracers as a bacterium swims past.

  16. Robotic vehicle with multiple tracked mobility platforms

    Science.gov (United States)

    Salton, Jonathan R [Albuquerque, NM; Buttz, James H [Albuquerque, NM; Garretson, Justin [Albuquerque, NM; Hayward, David R [Wetmore, CO; Hobart, Clinton G [Albuquerque, NM; Deuel, Jr., Jamieson K.

    2012-07-24

    A robotic vehicle having two or more tracked mobility platforms that are mechanically linked together with a two-dimensional coupling, thereby forming a composite vehicle of increased mobility. The robotic vehicle is operative in hazardous environments and can be capable of semi-submersible operation. The robotic vehicle is capable of remote controlled operation via radio frequency and/or fiber optic communication link to a remote operator control unit. The tracks have a plurality of track-edge scallop cut-outs that allow the tracks to easily grab onto and roll across railroad tracks, especially when crossing the railroad tracks at an oblique angle.

  17. Roentgenographic features of neurofibromatosis von Recklinghausen

    Energy Technology Data Exchange (ETDEWEB)

    Galanski, M.; Vogelsang, H.; Cramer, B.M.; Thun, F.; Peters, P.E.

    1983-10-01

    The basic abnormality of neurofibromatosis consists not only of a maldevelopment of the neuroectoderm but also of the mesoderm. Therefore any organ or system of the body may be involved. Following a short clinical review of the central (acoustic) and peripheral type the well known and the more unusual radiographic findings are summarized. They include cranial and intracranial manifestations (orbitosphenoid dysplasia, bone defects of the skull, acoustic neuroma, glioma of the optic nerve and chiasm, meningioma), spinal lesions (scoliosis, vetebral scalloping, meningocele, neuroma, ependymoma), skeletal abnormalities (pseudarthrosis), cardiovascular manifestations, pulmonary fibrosis, tumors of the gastrointestinal and urinary tract and different endocrinopathies. Some of the roentgeologic symptoms are very characteristic and allow definitive diagnosis.

  18. Model flames in the Boussinesq limit: The case of pulsating fronts

    Science.gov (United States)

    Vladimirova, N.; Rosner, R.

    2005-06-01

    We extend earlier work on the nonlinear behavior of premixed flames in a gravitationally stratified medium, subject to the Boussinesq approximation, in two dimensions. The main result is that the nature of the traveling burning front is largely determined by the form of the adopted boundary conditions on the side walls: while symmetric boundary conditions lead to stably scalloped traveling wave solutions, loss of symmetry leads to the development of pulsating fronts. However, despite differences in geometrical features, the symmetric and asymmetric systems obey the same scaling behavior for the average effective flame speed.

  19. Small scale high resolution LiDAR measurements of a subglacial conduit

    Science.gov (United States)

    Mankoff, K. D.; Gulley, J.

    2012-04-01

    We present direct measurements of surface roughness in a sub-glacial conduit system underneath the Rieperbreen Glacier, Svalbard, Norway. Data was collected with a low-cost (129 USD) Microsoft Kinect video game device used as a LIDAR sensor. Surface roughness is a primary control on water flow in rivers, channels, and cave conduit systems and understanding the effects of surface roughness on water flow has been problematic due to lack of direct measurements of roughness in natural systems. We use the ice scallop dimensions to derive flow velocity and explore implications of the changing roughness parameters as the cave grows and shrinks.

  20. Environmental Guide for ASW in Eastern Canadian Shallow Waters. Part 2: Environmental Data

    Science.gov (United States)

    1991-01-01

    charts which hav~e been produced by the Canadian Hydropraphic Service (CBS) of the Department of Fisheria and Oteans: "* Map 801-A Bay of Fundy to Gulf...Key. fishing atom a) baring, b) machu , and c) capan ..... 180 5.10 Key fishing aru a) lobster , b) mow cab, c) scallops and d) shrip...qpcally filed by 30 to 60 m of sdm ts(maximu 120 in). - Downing Basin, Conception Bay Axeas This region contains thick glacial 1uSDl reaching a

  1. Gyrate atrophy of choroid and retina with myopia, cataract and systemic proximal myopathy: A rare case report from rural India

    Directory of Open Access Journals (Sweden)

    Surekha Bangal

    2012-12-01

    Full Text Available AbstractGyrate atrophy is a rare metabolic disease with autosomal recessive inheritance pattern characterised by hyperornithinemia and typical ocular findings. This report presents a 17-year-old intellectually challenged girl consulting for a progressive fall of visual acuity with night blindness. Fundus examination showed patches of chorioretinal atrophy with typical scalloped borders and peri vascular pigmentation in the equatorial region. Fundus fluroscein angiography revealed characteristic staining pattern. Other ocular associations included myopia and posterior sub capsular cataract. Progressive systemic proximal myopathy was one of the associated features. Dietary supplementation of vitamin B6 was advised.

  2. Concept Definition: Retirement for Cause of F100 Rotor Components.

    Science.gov (United States)

    1980-09-01

    approach to the F100 engine. The study was directed primarily toward rotating components of that engine, specifically the various disks and airseals ...Web to Bore 0.010 depth and Ti 6246 3rd-Stage Disk Live Rim >0.017 dia Balance Flange Scallop Integral Arm Bolthole Bore Ti 6246 2nd-Stage Airseal Oil...Waspaloy 8th-Stage Disk Web Bolthole Live Rim Bore Waspaoy 12th-Stage Disk Live Rim 0.010 to Waspaloy 6th-Stage Airseal Antirotation Window 0.018 depth

  3. Keratocystic odontogenic tumor: case report with CT and ultrasonography findings

    Energy Technology Data Exchange (ETDEWEB)

    Sumer, A Pinar; Sumer, Mahmut; Celenk, Peruze; Danaci, Murat [Faculty of Dentistry, University of Ondokuz Mayis, Samsun (Turkmenistan); Gunhan, Oemer [Gulhane Military Medicine Academy, Ankara (Turkmenistan)

    2012-03-15

    Keratocystic odontogenic tumor (KCOT) is a benign odontogenic tumor with a potentially aggressive and infiltrative behavior. KCOT is most commonly occurred in mandible and demonstrate a unilocular, round, oval, scalloped radiolucent area, while large lesions may appear multilocular. An important characteristic of KCOT is its propensity to grow in an antero-posterior direction within medullary cavity of bone causing minimal expansion. Definitive diagnosis relies on histological examination. In this report, a KCOT that had an expansion both buccal and lingual cortical bone is described including its features in computed tomography and ultrasonographic exams. The lesion was removed surgically via an intraoral approach under local anesthesia and histologically reported as a KCOT.

  4. Comparative eicosanoid physiology in invertebrate animals.

    Science.gov (United States)

    Stanley-Samuelson, D W

    1991-05-01

    A comparative survey of eicosanoid physiology in invertebrate animals is presented. Topics include host skin penetration behavior in blood flukes, oocyte maturation in starfishes, prevention of polyspermic fertilizations in sea urchins, ion regulation in bivalves, egg production in snails, egg release in scallops, neurobiology of Aplysia, hatching in barnacles, and release of egg-laying behavior in some insects. Some eicosanoid actions, such as ion regulation, may be common to most vertebrate and invertebrate animals, whereas other actions, such as mediation of whole organism behavior, are not shared. Comparative physiology is revealing that the biological significance of eicosanoids extends far beyond vertebrate animals.

  5. Debris avalanches and slumps on the margins of volcanic domes on Venus: Characteristics of deposits

    Science.gov (United States)

    Bulmer, M. H.; Guest, J. E.; Beretan, K.; Michaels, Gregory A.; Saunders, R. Stephen

    1992-01-01

    Modified volcanic domes, referred to as collapsed margin domes, have diameters greater than those of terrestrial domes and were therefore thought to have no suitable terrestrial analogue. Comparison of the collapsed debris using the Magellan SAR images with volcanic debris avalanches on Earth has revealed morphological similarities. Some volcanic features identified on the seafloor from sonar images have diameters similar to those on Venus and also display scalloped margins, indicating modification by collapse. Examination of the SAR images of collapsed dome features reveals a number of distinct morphologies to the collapsed masses. Ten examples of collapsed margin domes displaying a range of differing morphologies and collapsed masses have been selected and examined.

  6. Trends in use of the only Food and Drug Administration-approved commercially available fenestrated endovascular aneurysm repair device in the United States.

    Science.gov (United States)

    Simons, Jessica P; Shue, Bing; Flahive, Julie M; Aiello, Francesco A; Steppacher, Robert C; Eaton, Elizabeth A; Messina, Louis M; Schanzer, Andres

    2017-05-01

    Fenestrated endografts are customized, patient-specific, endovascular devices with potential to significantly reduce morbidity and mortality of short-neck infrarenal and juxtarenal abdominal aortic aneurysm repair. The Zenith fenestrated endovascular graft (ZFEN) for abdominal aortic aneurysms (Cook Medical, Bloomington, Ind), Food and Drug Administration-approved in 2012, remains the only fenestrated device available in the United States. This technology is among the most technically complex catheter-based procedures and, therefore, inherently associated with serious risk for device-related complications. We sought to define patterns of physician and hospital adoption of ZFEN. Deidentified datasets containing numbers of physicians trained, orders by physicians and hospitals, and designs (fenestration/scallop configuration) was provided for U.S. ZFEN devices ordered (April 2012-August 2015). We evaluated the number of physicians trained, the number of devices ordered, hospital characteristics, and fenestration/scallop design configurations. Cook Medical assembled the datasets but played no role in study design, analysis, or interpretation of data. Between April 2012 and August 2015, 553 physicians attended formal ZFEN training sessions, 388 (70%) of whom ordered a total of 2669 devices. An increase in orders per month (nine in June 2012 and 91 in August 2015, 911% growth; P 20 devices. For physicians contributing >6 months of data (n = 336), the average number of devices ordered per year was three (standard deviation, 4); 272 (81%) ordered ≤ 5 devices/year, 15 (4.5%) ordered 11-20 devices/year, and 3 (0.9%) ordered >20 devices/year. Of devices with design details available (2618 of 2669; 98%), most common designs were 2 small fenestrations/1 scallop (1443; 55%), 2 small fenestrations/1 large fenestration (568; 22%), 1 small fenestration/1 scallop (173, 6.6%), and 2 small fenestrations (169; 6.5%). The average number of target vessels incorporated in each

  7. Venus - False Color of Volcanic Plains

    Science.gov (United States)

    1992-01-01

    This Magellan full-resolution mosaic of Venus, centered at 10 degrees north latitude, 301 degrees east longitude, shows an area replete with diverse volcanic features. The image, of an area 489 kilometers long by 311 kilometers wide (303 by 193 miles), is dominated by volcanic plains which appear mottled because of varying roughnesses of each solidified lava flow. The rougher the terrain the brighter it appears in the radar image. The small, bright bumps clustered in the left portion of the image are a grouping of small volcanoes called a shield field. Each shield volcano is approximately 2 to 5 kilometers (1.2 to 3.1 miles) in diameter and has very subdued relief. It is believed that the lava flows that make up each shield originates from a common source. To the right of the shield field is another type of volcano, called a scalloped dome. It is 25 kilometers (16 miles) in diameter and has a central pit. Some of the indistinct lobe-shaped pattern around the dome may either be lava flows or rocky debris which has fallen from the scalloped cliffs surrounding the domes. The small radial ridges characteristic of scalloped domes are remnants of catastrophic landslides. To the right of that feature is a large depression called a volcanic caldera. The caldera was formed when lava was expelled from an underground chamber, which when emptied, subsequently collapsed forming the depression. The feature furthermost to the east (right) is another scalloped dome, 35 kilometers (22 miles) in diameter. That feature is unusual in that lava came out through the southeastern margin, rafting a large portion of the dome for 20 kilometers (12 miles). The lava continues into the lower right portion of the area in the image. Its steep rounded boundaries suggest it was a very sticky, oozing lava. That same type of lava is what scientists propose formed the steep-sided domes such as the bright, round feature, slightly northeast of center. It is highly likely that the features are all part

  8. Ocular and olfactory forebrain abnormalities within a neonatal alpaca (Vicugna pacos).

    Science.gov (United States)

    Hostnik, Eric T; Wickins, Sophie C; Conway, Julia A; Dark, Michael J

    2012-07-01

    A 5-day-old Huacaya alpaca cria (Vicugna pacos) was euthanized due to deteriorating health. At birth, the cria had ophthalmologic abnormalities, but had appropriate mentation. At 2 days of age, the cria gradually stopped suckling and began to circle. At 5 days old, the owner elected euthanasia due to declining clinical condition. Grossly, the right iris had a scalloped pupillary margin, and the right olfactory bulb was malformed. Histopathology revealed persistent hyperplastic primary vitreous bilaterally and iridal abnormalities, as well as aplasia of the olfactory ventricle, olfactory tract, and olfactory foramen on the right side.

  9. Shark populations in Chatham and Wafer bays, Isla del Coco National Park, Costa Rica.

    OpenAIRE

    Zanella, Ilena; López-Garro, Andrés; Martínez, Frank; Golfín-Duarte, Geiner; Morales, Keylor

    2016-01-01

     At least fourteen species of sharks live in the Marine Protected Area of Isla del Coco National Park (ICNP), some are resident species such as the whitetip reef shark (Triaenodon obesus); others are migratory and visit the National Park throughout the year, e.g. the scalloped hammerhead shark (Sphyrna lewini) and the whale shark (Rhincodon typus). Between March 2010 and August 2012 six expeditions out to the ICNP were carried, during this period 25 night trips (from 18:00 to 22:00 hr) for sh...

  10. Sterol composition of shellfish species commonly consumed in the United States

    Directory of Open Access Journals (Sweden)

    Katherine M. Phillips

    2012-10-01

    Full Text Available Background: Shellfish can be a component of a healthy diet due to a low fat and high protein content, but the cholesterol content of some species is often cited as a reason to limit their consumption. Data on levels of non-cholesterol sterols in commonly consumed species are lacking. Objective: Shellfish were sampled and analyzed to update sterol data in the United States Department of Agriculture (USDA National Nutrient Database for Standard Reference. Design: Using a nationwide sampling plan, raw shrimp and sea scallops, canned clams, and steamed oysters, blue crab, and lobster were sampled from 12 statistically selected supermarkets across the United States in 2007-08. For each species, four composites were analyzed, each comprised of samples from three locations; shrimp and scallops from six single locations were also analyzed separately. Using validated analytical methodology, 14 sterols were determined in total lipid extracts after saponification and derivatization to trimethylsilyethers, using gas chromatography for quantitation and mass spectrometry for confirmation of components. Results: Crab, lobster, and shrimp contained significant cholesterol (96.2–27 mg/100 g; scallops and clams had the lowest concentrations (23.4–30.1 mg/100 g. Variability in cholesterol among single-location samples of shrimp was low. The major sterols in the mollusks were brassicasterol (12.6–45.6 mg/100 g and 24-methylenecholesterol (16.7–41.9 mg/100 g, with the highest concentrations in oysters. Total non-cholesterol sterols were 46.5–75.6 mg/100 g in five single-location scallops samples, but 107 mg/100 g in the sixth, with cholesterol also higher in that sample. Other prominent non-cholesterol sterols in mollusks were 22-dehydrocholesterol, isofucosterol, clionasterol, campesterol, and 24-norcholesta-5,22-diene-3β-ol (4–21 mg/100 g. Conclusions: The presence of a wide range of sterols, including isomeric forms, in shellfish makes the analysis

  11. New Records of Hippolytid Shrimps, Lebbeus speciosus and Lebbeus comanthi (Crustacea: Decapoda: Caridea from the East Sea, Korea

    Directory of Open Access Journals (Sweden)

    Chu Lee

    2013-01-01

    Full Text Available Two species of the hippolytid shrimps, Lebbeus speciosus and Lebbeus comanthi, are described and illustrated for the first time in Korea. They were collected from the East Sea. Lebbeus speciosus was found in a scallop farm of Jumunjin, Gangneung, and L. comanthi associated with crinoids, was found in Gampo, Gyeongju. The difference between these two related species is in the number of dorsal teeth of the rostrum, five teeth in L. speciosus and a single tooth in L. comanthi. The Korean Lebbeus species has increased to 6 species by the present report. They are L. grandimana, L. polaris, L. unalaskensis, L. groenlandicus, L. speciosus, and L. comanthi.

  12. JGI Plant Genomics Gene Annotation Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Shengqiang; Rokhsar, Dan; Goodstein, David; Hayes, David; Mitros, Therese

    2014-07-14

    Plant genomes vary in size and are highly complex with a high amount of repeats, genome duplication and tandem duplication. Gene encodes a wealth of information useful in studying organism and it is critical to have high quality and stable gene annotation. Thanks to advancement of sequencing technology, many plant species genomes have been sequenced and transcriptomes are also sequenced. To use these vastly large amounts of sequence data to make gene annotation or re-annotation in a timely fashion, an automatic pipeline is needed. JGI plant genomics gene annotation pipeline, called integrated gene call (IGC), is our effort toward this aim with aid of a RNA-seq transcriptome assembly pipeline. It utilizes several gene predictors based on homolog peptides and transcript ORFs. See Methods for detail. Here we present genome annotation of JGI flagship green plants produced by this pipeline plus Arabidopsis and rice except for chlamy which is done by a third party. The genome annotations of these species and others are used in our gene family build pipeline and accessible via JGI Phytozome portal whose URL and front page snapshot are shown below.

  13. SHELLFISH OF THE RIVER KRKA MOUTH - FISHING AND FARMING

    Directory of Open Access Journals (Sweden)

    Drago Marguš

    2004-03-01

    Full Text Available U radu je iznesen kratki prikaz zemljopisnog položaja rijeke Krke, osobitosti njezina ušća, to izlova i istraživanja prirodnih populacija školjkaša. Poseban je naglasak stavljen na prikaz mogućnosti kontroliranog uzgoja školjkaša u bočatim vodama ušća. U ušću rijeke Krke utvrđeno je 56 svojti iz 27 porodica. Najrasprostranjenije su ove svojte: dagnja (Mytilus galloprovincialis, kamenica (Ostrea edulis, a česte su: jestiva srčanka (Cerastoderma glaucum, prnjavica (Venus verrucosa, kućica (Tapes decussatus, kunjka (Arca noae, mala kapica (Chlamys varia i jakovska kapica (Pecten jacobaeus. Izlov prirodnih populacija školjkaša za prehranu tradicionalna je djelatnost i procjenjuje se na 100 tona u godini. Istraživanja mogućnosti kontroliranog uzgoja dagnje, kamenice, male kapice i jakovske kapice rezultirala su razvojem tehnologija konroliranog uzgoja dagnje i kamenice 1983., a jakovske kapice i male kapice godine 1989. Danas je proizvodnja organizirana na 25 lokaliteta, ukupne površine 87.142 m2, s mogućnošću proizvodnje oko 1.500 tona dagnji i deset tisuća kamenica, a mogla bi se povećati iznad 10.000 tona.

  14. Chlamydophila psittaci Zoonotic Risk Assessment in a Chicken and Turkey Slaughterhouse▿

    Science.gov (United States)

    Dickx, V.; Geens, T.; Deschuyffeleer, T.; Tyberghien, L.; Harkinezhad, T.; Beeckman, D. S. A.; Braeckman, L.; Vanrompay, D.

    2010-01-01

    Chlamydophila psittaci causes respiratory disease in poultry and can be transmitted to humans. We conducted a C. psittaci zoonotic risk assessment study of a chicken and turkey slaughterhouse. Eighty-five percent of the slaughtered chicken flocks tested positive by PCR and culture. Genotype D was discovered. Fifty-seven percent of the slaughtered turkey flocks tested positive by PCR and culture. Genotype D was present. For the chicken slaughterhouse employees, 7.5% and 6% tested positive for C. psittaci by PCR and culture, respectively. In the turkey slaughterhouse, 87% and 61% of the employees tested positive by PCR and culture, respectively. All genotyped human samples contained genotype D. Using stationary bioaerosol monitoring by means of an MAS-100 ecosampler and ChlamyTrap collection medium, chlamydial DNA, and viable organisms were detected in both the chicken and turkey slaughterhouses. Positive air samples were most frequently found in the animal reception area and evisceration room. Zoonotic transmissions were very common, especially from processed turkeys. Accurate diagnostic monitoring and reporting of C. psittaci infections should be promoted in poultry workers. PMID:20592139

  15. Holocene molluscan assemblages in the Magellan region

    Directory of Open Access Journals (Sweden)

    Sandra Gordillo

    1999-12-01

    Full Text Available In the Magellan region, much of the shoreline of the Beagle Channel coast (54°53´S; 67° - 68°W is bordered by Holocene raised beaches, which contain a large number of molluscs and other shelled taxa. The purpose of this work is to document the presence of various molluscan assemblages deposited with little or no postmortem transportation. An epifaunal Chlamys patagonica palaeocommunity (ca. 8,000 - 7,000 BP and three infaunal (Tawera gayi, Ameghinomya antiqua - Hiatella solida and Ameghinomya antiqua - Ensis macha palaeocommunities (ca. 4,400 - 4,000 BP were recognized. All the assemblages studied represent shallow, subtidal, cold-temperate environments. Based on comparisons with modern benthic communities in this region, these associations show that no remarkable ecologic and climatic changes occurred during the period ca. 8,000 - 4,000 BP. Thus, an apparent stability of modern marine communities over a period of several thousand years is suggested.

  16. Early Pliocene Weddell Sea climate and seasonality reconstructed from bivalves and bryozoans

    Science.gov (United States)

    Williams, M.; Clark, N.; Okamura, B.; Zalasiewicz, J.; Johnson, A.; Leng, M. J.; Smellie, J.; Haywood, A.; Nelson-Laloe, A.; Taylor, P.

    2010-12-01

    Early Pliocene marine cheilostome bryozoans and bivalves are preserved in glacigenic and interglacial marine deposits of James Ross Island and Cockburn Island, northern Antarctic Peninsula. Several different marine bryozoan genera were incorporated into diamictites during Pliocene ice advance(s). Bryozoan zooid-size Mean Annual Range of Temperature (zs-MART) analysis provides estimates of seasonality which suggest annual marine temperatures for the James Ross Island region varied by at least 4°C and possibly by as much as 10°C during Early Pliocene warm intervals (compared with ca 2°C for present day). Coupled with evidence from oxygen isotope data from bivalves, Early Pliocene Weddell Sea warm intervals were evidently much warmer than present, with summer sea temperatures probably exceeding 5°C. Morphological (growth-increment) and oxygen isotope data from bivalves in the marine interglacial Cockburn Island Formation (dated at 4.7 Ma) indicate little or no sea ice present, supporting the theory that Chlamys-like bivalves have retreated from the Antarctic as sea ice increased in the late Pliocene. We demonstrate that bivalve and bryozoan growth-related morphologies, interpreted in conjunction with stable oxygen and carbon isotope data, provide a powerful tool for tracking high latitude climate in the Pliocene.

  17. Seafood sold in Sweden contains BMAA: A study of free and total concentrations with UHPLC–MS/MS and dansyl chloride derivatization

    Directory of Open Access Journals (Sweden)

    Matilda L. Salomonsson

    2015-01-01

    Full Text Available β-N-Methylamino-l-alanine (BMAA is a potential neurotoxin associated with the aquatic environment. Validated analytical methods for the quantification of both free and total concentrations of BMAA were used in an investigation of seafood purchased from different grocery stores in Uppsala, Sweden. The analysis was performed using ultra high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI–MS/MS and detection of BMAA as a dansyl derivate. The determined concentrations of free BMAA (after a simple trichloroacetic acid extraction in mussels and scallops were up to 0.46 μg g−1 wet homogenate. The total BMAA (after hydrochloric acid hydrolysis levels were between 0.29 and 7.08 μg g−1 wet mussel homogenate. The highest concentration of total BMAA was found in imported cooked and canned mussels which contained about ten times the quantity of BMAA measured in domestic cooked and frozen mussels. In this study it was also concluded that BMAA could be detected in seafood origin from four different continents. The risks associated with human exposure to BMAA through food are unknown today. However, the results of this study show that imported seafood in Sweden contain BMAA, indicating that this area needs more investigation, including a risk assessment regarding the consumption of e.g., mussels, scallops and crab.

  18. Major cranial changes during Triceratops ontogeny.

    Science.gov (United States)

    Horner, John R; Goodwin, Mark B

    2006-11-07

    This is the first cranial ontogenetic assessment of Triceratops, the well-known Late Cretaceous dinosaur distinguished by three horns and a massive parietal-squamosal frill. Our analysis is based on a growth series of 10 skulls, ranging from a 38 cm long baby skull to about 2 m long adult skulls. Four growth stages correspond to a suite of ontogenetic characters expressed in the postorbital horns, frill, nasal, epinasal horn and epoccipitals. Postorbital horns are straight stubs in early ontogeny, curve posteriorly in juveniles, straighten in subadults and recurve anteriorly in adults. The posterior margin of the baby frill is deeply scalloped. In early juveniles, the frill margin becomes ornamented by 17-19 delta-shaped epoccipitals. Epoccipitals are dorsoventrally compressed in subadults, strongly compressed and elongated in adults and ultimately merge onto the posterior frill margin in older adults. Ontogenetic trends within and between growth stages include: posterior frill margin transitions from scalloped to wavy and smooth; progressive exclusion of the supraoccipital from the foramen magnum; internal hollowing at the base of the postorbital horns; closure of the midline nasal suture; fusion of the epinasal onto the nasals; and epinasal expansion into a morphologically variable nasal horn. We hypothesize that the changes in horn orientation and epoccipital shape function to allow visual identity of juveniles, and signal their attainment of sexual maturity.

  19. Response of the hammerhead shark olfactory epithelium to amino acid stimuli.

    Science.gov (United States)

    Tricas, Timothy C; Kajiura, Stephen M; Summers, Adam P

    2009-10-01

    Sharks and rays are highly sensitive to chemical stimuli in their natural environment but several hypotheses predict that hammerhead sharks, with their expanded head and enlarged olfactory epithelium, have particularly acute olfactory systems. We used the electro-olfactogram (EOG) technique to compare the relative response of the scalloped hammerhead shark (Sphyrna lewini) olfactory epithelium to 20 proteinogenic amino acids and determine the sensitivity for 6 amino acids. At micromolar concentrations, cysteine evoked the greatest EOG response which was approximately twice as large as that of alanine. The weakest response was obtained for proline followed by aspartic acid and isoleucine. The olfactory epithelium showed adaptation to sequential stimulation, and recovery was related to the inter-stimulus time period. Estimated EOG response thresholds were in the sub-nanomolar range for both alanine (9.2 x 10(-11) M) and cysteine (8.4 x 10(-10) M) and in the micromolar range for proline and serine. These thresholds from 10(-10) to 10(-6) M for the scalloped hammerhead shark are comparable or lower than those reported for other teleost and elasmobranch species. Future work should focus on binary and more complex compounds to test for competition and cross-adaptation for different classes of peripheral receptors, and their responses to molecules found in biologically relevant stimuli.

  20. Crossing lines: a multidisciplinary framework for assessing connectivity of hammerhead sharks across jurisdictional boundaries

    Science.gov (United States)

    Chin, A.; Simpfendorfer, C. A.; White, W. T.; Johnson, G. J.; McAuley, R. B.; Heupel, M. R.

    2017-04-01

    Conservation and management of migratory species can be complex and challenging. International agreements such as the Convention on Migratory Species (CMS) provide policy frameworks, but assessments and management can be hampered by lack of data and tractable mechanisms to integrate disparate datasets. An assessment of scalloped (Sphyrna lewini) and great (Sphyrna mokarran) hammerhead population structure and connectivity across northern Australia, Indonesia and Papua New Guinea (PNG) was conducted to inform management responses to CMS and Convention on International Trade in Endangered Species listings of these species. An Integrated Assessment Framework (IAF) was devised to systematically incorporate data across jurisdictions and create a regional synopsis, and amalgamated a suite of data from the Australasian region. Scalloped hammerhead populations are segregated by sex and size, with Australian populations dominated by juveniles and small adult males, while Indonesian and PNG populations included large adult females. The IAF process introduced genetic and tagging data to produce conceptual models of stock structure and movement. Several hypotheses were produced to explain stock structure and movement patterns, but more data are needed to identify the most likely hypothesis. This study demonstrates a process for assessing migratory species connectivity and highlights priority areas for hammerhead management and research.

  1. Mycale (Aegogropila magellanica (Porifera: Demospongiae in the southwestern Atlantic Ocean: endobiotic fauna and new distributional information

    Directory of Open Access Journals (Sweden)

    Laura Schejter

    2012-10-01

    Full Text Available The composition of endobionts in the sponge Mycale (Aegogropila magellanica at the shelf-break, near 100 m depth, in the Argentine Sea was studied. We also provide new information on the distribution of M. (A. magellanica, extending its northern limit to 38º36.02’S and 55º44.68’W, 91 m in the SW Atlantic Ocean. The main Patagonian scallop fishing grounds are located in the shelf-break frontal area of the Argentine Sea. In this area, M. (A. magellanica plays an important role in providing habitat for at least 23 taxa of small invertebrates, mostly crustaceans (66% to 96% of the total number of individuals. On average, this sponge hosted 348 individuals per litre; Aristias cf. antarcticus (Amphipoda was the most frequent and abundant species. Other organisms commonly found were the isopod Caecognathia sp., the amphipod Leucothoe cf. spinicarpa, the bivalve Hiatella meridionalis and the ophiuroid Ophiactis asperula. As previously demonstrated for other sponges, our study suggests that M. (A. magellanica enhances benthic biodiversity, as it shelters a variety of invertebrate species. In areas of soft and flat substrate, erect and sessile epifauna usually acts as an ecosystem engineer, structuring the architecture of the habitat by increasing the sea-bottom complexity. Mass removal of this fauna due to intense trawling activities on Patagonian scallop beds could have devastating effects on local biodiversity.

  2. Crossing lines: a multidisciplinary framework for assessing connectivity of hammerhead sharks across jurisdictional boundaries.

    Science.gov (United States)

    Chin, A; Simpfendorfer, C A; White, W T; Johnson, G J; McAuley, R B; Heupel, M R

    2017-04-21

    Conservation and management of migratory species can be complex and challenging. International agreements such as the Convention on Migratory Species (CMS) provide policy frameworks, but assessments and management can be hampered by lack of data and tractable mechanisms to integrate disparate datasets. An assessment of scalloped (Sphyrna lewini) and great (Sphyrna mokarran) hammerhead population structure and connectivity across northern Australia, Indonesia and Papua New Guinea (PNG) was conducted to inform management responses to CMS and Convention on International Trade in Endangered Species listings of these species. An Integrated Assessment Framework (IAF) was devised to systematically incorporate data across jurisdictions and create a regional synopsis, and amalgamated a suite of data from the Australasian region. Scalloped hammerhead populations are segregated by sex and size, with Australian populations dominated by juveniles and small adult males, while Indonesian and PNG populations included large adult females. The IAF process introduced genetic and tagging data to produce conceptual models of stock structure and movement. Several hypotheses were produced to explain stock structure and movement patterns, but more data are needed to identify the most likely hypothesis. This study demonstrates a process for assessing migratory species connectivity and highlights priority areas for hammerhead management and research.

  3. A new fibrinogen-related protein from Argopecten irradians (AiFREP-2) with broad recognition spectrum and bacteria agglutination activity.

    Science.gov (United States)

    Yang, Chuanyan; Wang, Leilei; Zhang, Huan; Wang, Lingling; Huang, Mengmeng; Sun, Zhibin; Sun, Ying; Song, Linsheng

    2014-05-01

    Fibrinogen-related proteins (FREPs) are a kind of pattern recognition receptors (PRRs) containing fibrinogen-like (FBG) domains, and they play curial roles in the innate immune response. In the present study, a new FREP protein was identified from bay scallop Argopecten irradians (designated as AiFREP-2). The full-length cDNA of AiFREP-2 was of 1299 bp with an open reading frame of 762 bp encoding a polypeptide of 253 amino acids, including a signal sequence and an FBG domain. The FBG domain in AiFREP-2 was highly similar to those of ficolins, tenascins and other FREPs. The mRNA expression of AiFREP-2 could be detected in all the examined tissues with the highest level in gill. The mRNA expression of AiFREP-2 in hemocytes was significantly up-regulated post the stimulation of lipopolysaccharide (LPS), peptidoglycan (PGN) and β-glucan (GLU) (P agglutination activity towards Gram-negative bacteria V. anguillarum and Gram positive bacteria S. aureus. The results indicated that AiFREP-2 was involved in the immune response against Gram-negative bacteria, Gram-positive bacteria and fungus as a PRR in bay scallop, and the information was helpful to understand the innate immune defense mechanisms of mollusks. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Electromagnetic Forces in a Hybrid Magnetic-Bearing Switched-Reluctance Motor

    Science.gov (United States)

    Morrison, Carlos R.; Siebert, Mark W.; Ho, Eric J.

    2008-01-01

    Analysis and experimental measurement of the electromagnetic force loads on the hybrid rotor in a novel hybrid magnetic-bearing switched-reluctance motor (MBSRM) have been performed. A MBSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The MBSRM discussed in this report has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated using only one set of four stator poles, while a second set of four stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. Static torque and radial force analysis were done for rotor poles that were oriented to achieve maximum and minimum radial force loads on the rotor. The objective is to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. Two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, were employed in formulating the electromagnetic radial force equations. Reasonable agreement between the experimental and the theoretical radial force loads predictions was obtained with typical magnetic bearing derating factors applied to the predictions.

  5. Etching radical controlled gas chopped deep reactive ion etching

    Science.gov (United States)

    Olynick, Deidre; Rangelow, Ivo; Chao, Weilun

    2013-10-01

    A method for silicon micromachining techniques based on high aspect ratio reactive ion etching with gas chopping has been developed capable of producing essentially scallop-free, smooth, sidewall surfaces. The method uses precisely controlled, alternated (or chopped) gas flow of the etching and deposition gas precursors to produce a controllable sidewall passivation capable of high anisotropy. The dynamic control of sidewall passivation is achieved by carefully controlling fluorine radical presence with moderator gasses, such as CH.sub.4 and controlling the passivation rate and stoichiometry using a CF.sub.2 source. In this manner, sidewall polymer deposition thicknesses are very well controlled, reducing sidewall ripples to very small levels. By combining inductively coupled plasmas with controlled fluorocarbon chemistry, good control of vertical structures with very low sidewall roughness may be produced. Results show silicon features with an aspect ratio of 20:1 for 10 nm features with applicability to nano-applications in the sub-50 nm regime. By comparison, previous traditional gas chopping techniques have produced rippled or scalloped sidewalls in a range of 50 to 100 nm roughness.

  6. Gingival biotype assessement: visual inspection relevance and maxillary versus mandibular comparison.

    Science.gov (United States)

    Cuny-Houchmand, Madline; Renaudin, Stéphane; Leroul, Mustapha; Planche, Lucie; Guehennec, Laurent Le; Soueidan, Assem

    2013-01-01

    This clinical study was aimed at evaluating the accuracy of gingival visual inspection procedures during clinical examination and determining whether differences existed between the maxillary and mandibular gingival biotypes. The study included 53 patients and 124 clinicians. The clinicians were asked to assign to each subject, using photographic documents, one of three biotypes: thin-scalloped, thick-scalloped, or thick-flat gingival biotype. A total of 19716 responses were collected for statistical analysis. Identification accuracy of the gingival biotype and the intra-examiner repeatability presented poor highlighting of the limited relevance of visual inspection. In addition, the percent of agreement between classifications based on the global view of both the maxilla and mandible and the classification based on the individual mandibular or maxillary anterior teeth was not statistically significant. Based on the above results, it can be concluded that a simple visual inspection is not effective for the identification of gingival biotype. Furthermore, evidence suggests that a difference of biotype between the maxilla and the mandible in the same patient is conceivable. Therefore, orthodontic clinical examination should incorporate a reproducible method of determining the individualized gingival biotype for each group of teeth that will be moved.

  7. Characteristics of periodontal biotype, its dimensions, associations and prevalence: a systematic review.

    Science.gov (United States)

    Zweers, Jeroen; Thomas, Renske Z; Slot, Dagmar E; Weisgold, Arnold S; Van der Weijden, Fridus G A

    2014-10-01

    The objectives of this review were as follows: What are characteristics used to define various forms of periodontal biotypes? What are their anatomic dimensions in relation to the definition? In addition, what is the association between these various characteristics in relation to the periodontal biotypes? Furthermore, what is the prevalence of various forms of periodontal biotypes in the population? The PubMed-MEDLINE, the Cochrane-CENTRAL and EMBASE databases were searched through up and till June 2013 to identify any appropriate studies regarding the aim. Appropriate studies were those reporting characteristics of various forms of periodontal biotype and its dimensions. These characteristics were gingival thickness (GT), gingival morphotype (GM), tooth dimensions (TD), keratinized tissue (KT) and bone morphotype (BM). The search yielded 2581 unique papers, after selection resulted in 12 publications that met the eligibility criteria. In general, the available definitions are found to be unclear and sometimes inconsistent. However, based on the available literature, the three biotypes thin scalloped, thick flat and thick scalloped seem a comprehensive categorization in defining periodontal biotypes in the population. The dental, gingival and osseous dimensions have a weak to moderate association. Only between gingival thickness, keratinized tissue and bone morphotype uniform positive associations are found. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Breaking out of the comfort zone: El Niño-Southern Oscillation as a driver of trophic flows in a benthic consumer of the Humboldt Current ecosystem.

    Science.gov (United States)

    Riascos, José M; Solís, Marco A; Pacheco, Aldo S; Ballesteros, Manuel

    2017-06-28

    The trophic flow of a species is considered a characteristic trait reflecting its trophic position and function in the ecosystem and its interaction with the environment. However, climate patterns are changing and we ignore how patterns of trophic flow are being affected. In the Humboldt Current ecosystem, arguably one of the most productive marine systems, El Niño-Southern Oscillation is the main source of interannual and longer-term variability. To assess the effect of this variability on trophic flow we built a 16-year series of mass-specific somatic production rate (P/B) of the Peruvian scallop (Argopecten purpuratus), a species belonging to a former tropical fauna that thrived in this cold ecosystem. A strong increase of the P/B ratio of this species was observed during nutrient-poor, warmer water conditions typical of El Niño, owing to the massive recruitment of fast-growing juvenile scallops. Trophic ecology theory predicts that when primary production is nutrient limited, the trophic flow of organisms occupying low trophic levels should be constrained (bottom-up control). For former tropical fauna thriving in cold, productive upwelling coastal zones, a short time of low food conditions but warm waters during El Niño could be sufficient to waken their ancestral biological features and display massive proliferations. © 2017 The Author(s).

  9. Statistical Aspects of Spatial Variation.

    Science.gov (United States)

    West, Robert M.

    Available from UMI in association with The British Library. A review is given of kriging and other methods of interpolating spatially varying data. The problem of interpolation is viewed as being equivalent to that of reconstructing a spatial stochastic process on IR^{rm d} from partial observations at particular points in space. The intractability of inference problems for spatial processes motivates the development of Monte Carlo simulation methods so that the performance of interpolators can be assessed and comparisons can be made of estimation and testing procedures. New simulation methods are proposed and compared with existing methods such as turning bands. Models for lattice processes are also reviewed. In particular, it is demonstrated that the orthant models on doubz^{rm d} form a smaller class than that claimed by Tjostheim (1978). The stage where the construction of such models fails is identified and instructive counter-examples are given. Methods are also advanced for the simulation of random fields on doubz^{rm d}. New limit results are obtained from sequences of random fields defined on a lattice as the lattice spacing shrinks to zero. These show that generalized random fields arise naturally in the context of stochastic modelling of soil fertility and other essentially discontinuous phenomena. The Norwegian government have identified the need for the control of scallop fishing in its waters. This involves the accurate estimation of existing resources. The final chapter contains a practical investigation of scallop data using some of the theory developed earlier in this thesis.

  10. The influence of a large SW Atlantic shelf-break frontal system on epibenthic community composition, trophic guilds, and diversity

    Science.gov (United States)

    Mauna, A. Cecilia; Acha, E. Marcelo; Lasta, Mario L.; Iribarne, Oscar O.

    2011-08-01

    Productivity gradients (i.e., through bottom-up control) have an important influence on variability in species diversity and community composition in marine systems. At the SW Atlantic shelf-break front (SBF), we hypothesized that a high and stable food supply in areas under the core of a frontal influence (F) promotes a different benthic community structure (i.e., species diversity, taxa biomasses, and composition of feeding guilds) than in areas located under marginal influences of the front (M). In 2007, we sampled 34 trawling stations located across the SBF to evaluate this hypothesis. We compared epibenthic community composition, diversity indices, and species and trophic guild biomass in F and M areas. We observed differences in community composition, predator biomass, and the biomass of some taxa. However, we did not detect any changes in diversity indices, suspension feeder biomass, or grazer-omnivore biomass. The scallop, Zygochlamys patagonica, sponges, and the brittle star, Ophiacantha vivipara, together with the sea star Diplasterias brandtii characterized frontal areas. Marginal areas were characterized by the scallop, Z. patagonica, the parchment worm, Chaetopterus variopedatus, the basket star, Gorgonocephalus chilensis, the sea urchin, Austrocidaris canaliculata, and the sea star, Ctenodiscus australis. These shifts in taxa were not always reflected in biomass differences between areas. These results demonstrate that spatial variations in oceanographic structure, even over spatial scales of tens of kilometers, can affect composition and shift species dominance in benthic communities.

  11. Domoic Acid - A New Toxin in the Croatian Adriatic Shellfish Toxin Profile

    Directory of Open Access Journals (Sweden)

    Ivona Marasović

    2010-10-01

    Full Text Available This is the first study that presents concentrations of domoic acid detected in the whole shellfish tissue from breeding and harvesting areas along the Croatian coast of the Adriatic Sea during the period 2006 to 2008. Shellfish sample analyses after SAX cleaning procedures, using a UV-DAD-HPLC system, showed the presence of domoic acid in four species. The most prevalent of those species were the blue mussel (Mytilus galloprovincialis, followed by European flat oyster (Ostrea edulis, Mediterranean scallop (Pecten jacobaeus and proteus scallop (Flexopecten proteus. Domoic acid, a potentially lethal phycotoxin that causes amnesic shellfish poisoning (ASP, was detected for the first time in January 2006 with the highest value of 6.5486 μg g-1 in whole shellfish tissue. Pseudo-nitzschia spp. bloom events preceded these high domoic acid concentrations. According to this study, retention of domoic acid in the blue mussel M. galloprovincialis is more than 42 days. This investigation indicates the first presence of domoic acid in Croatian shellfish, but in concentrations under the regulatory limit (20 μg g-1, therefore shellfish consumption was not found to endanger human health.

  12. MRI findings in patients with central neurocytomas with special reference to differential diagnosis from other ventricular tumours near the foramen of Monro.

    Science.gov (United States)

    Niiro, Tadaaki; Tokimura, Hiroshi; Hanaya, Ryosuke; Hirano, Hirofumi; Fukukura, Yoshihiko; Sugiyma, Kazuhiko; Eguchi, Kuniki; Kurisu, Kaoru; Yoshioka, Hiroyuki; Arita, Kazunori

    2012-05-01

    We retrospectively evaluated 12 patients with histologically verified central neurocytoma (CN) to identify the MRI characteristics associated with this tumour. All tumours had heterogeneous signal intensity in their solid components and seven had a "soap bubble" or spongy appearance. Spicules were identified at the tumour periphery interfacing with the lateral ventricular walls. These spicules were formed by walls of multiple cysts of medium size. Undulation of the lateral ventricular wall attached to the tumour capsule was seen in nine patients. These spicules and undulations resulted in a "scalloping" appearance. In a diagnostic experiment to test the differential diagnosis of CN from other neoplasms near the foramen of Monro, the identification of scalloping made a greater contribution to the specificity and accuracy of the diagnosis than the soap bubble appearance. Thus, recognition of multiple cystic interfaces between the solid part of the tumour and the lateral ventricular wall on MRI may contribute to a correct preoperative diagnosis of CN. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. A Study on Prevalence of Dental Attrition and its Relation to Factors of Age, Gender and to the Signs of TMJ Dysfunction.

    Science.gov (United States)

    Yadav, Sangeeta

    2011-06-01

    A study was planned to determine the severity of dental attrition in adults of both sexes in different age groups and its possible relationship to temporomandibular disorders. 500 subjects comprising of 260 females and 240 males in the age group of 18-55 years were clinically examined for bruxism, attrition, and signs of temporomandibular disorders. Tooth sensitivity, tooth or restoration fracture, scalloping of tongue, ridging of buccal mucosa, TMJ sounds, muscle tenderness, TMJ tenderness, referred pain, pain on mouth opening and limitation of mouth opening were recorded along with attrition score in a proforma. The basic data was then analysed to arrive at certain conclusions. A high prevalence of attrition (88.0%) with increase in age (P attrition with some of the signs of bruxism it was shown that tooth or restoration fracture and scalloping of tongue had no relation to the severity of attrition score. Whereas a significant relation was seen between attrition and tooth sensitivity (P attrition. Other signs of temporomandibular disorders such as joint tenderness, referred pain, joint sounds and limitation of mouth opening had no relation to attrition score. This study showed a limited association between the severity of attrition and TMJ dysfunction.

  14. Electromagnetic Radial Forces in a Hybrid Eight-Stator-Pole, Six-Rotor-Pole Bearingless Switched-Reluctance Motor

    Science.gov (United States)

    Morrison, Carlos R.; Siebert, Mark W.; Ho, Eric J.

    2007-01-01

    Analysis and experimental measurement of the electromagnet force loads on the hybrid rotor in a novel bearingless switched-reluctance motor (BSRM) have been performed. A BSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The BSRM has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated using only one set of stator poles. A second set of stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. Analysis was done for nonrotating rotor poles that were oriented to achieve maximum and minimum radial force loads on the rotor. The objective is to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. Two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, were employed in formulating the electromagnetic radial force equations. Reasonable agreement between the experimental results and the theoretical predictions was obtained with typical magnetic bearing derating factors applied to the predictions.

  15. Transcatheter mitral valve repair in osteogenesis imperfecta associated mitral valve regurgitation.

    Science.gov (United States)

    van der Kley, Frank; Delgado, Victoria; Ajmone Marsan, Nina; Schalij, Martin J

    2014-08-01

    Osteogenesis imperfecta is associated with increased prevalence of significant mitral valve regurgitation. Surgical mitral valve repair and replacement are feasible but are associated with increased risk of bleeding and dehiscence of implanted valves may occur more frequently. The present case report describes the outcomes of transcatheter mitral valve repair in a patient with osteogenesis imperfecta. A 60 year-old patient with osteogenesis imperfecta and associated symptomatic moderate to severe mitral regurgitation underwent transthoracic echocardiography which showed a nondilated left ventricle with preserved systolic function and moderate to severe mitral regurgitation. On transoesophageal echocardiography the regurgitant jet originated between the anterolateral scallops of the anterior and posterior leaflets (A1-P1). Considering the comorbidities associated with osteogenesis imperfecta the patient was accepted for transcatheter mitral valve repair using the Mitraclip device (Abbott vascular, Menlo, CA). Under fluoroscopy and 3D transoesophageal echocardiography guidance, a Mitraclip device was implanted between the anterolateral and central scallops with significant reduction of mitral regurgitation. The postoperative evolution was uneventful. At one month follow-up, transthoracic echocardiography showed a stable position of the Mitraclip device with no mitral regurgitation. Transcatheter mitral valve repair is feasible and safe in patients with osteogenesis imperfecta and associated symptomatic significant mitral regurgitation. Copyright © 2014 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  16. Genome-wide identification and expression profiling of the SOX gene family in a bivalve mollusc Patinopecten yessoensis.

    Science.gov (United States)

    Yu, Jiachen; Zhang, Lingling; Li, Yangping; Li, Ruojiao; Zhang, Meiwei; Li, Wanru; Xie, Xinran; Wang, Shi; Hu, Xiaoli; Bao, Zhenmin

    2017-09-05

    SOX family is composed of transcription factors that play vital roles in various developmental processes. Comprehensive understanding on evolution of the SOX family requires full characterization of SOX genes in different phyla. Mollusca is the second largest metazoan phylum, but till now, systematic investigation on the SOX family is still lacking in this phylum. In this study, we conducted genome-wide identification of the SOX family in Yesso scallop Patinopecten yessoensis and profiled their tissue distribution and temporal expression patterns in the ovaries and testes during gametogenesis. Seven SOX genes were identified, including SOXB1, B2, C, D, E, F and H, representing the first record in protostomes with SOX members identical to that proposed to exist in the last common ancestor of chordates. Genomic structure analysis identified relatively conserved exon-intron structures, accompanied by intron insertion. Quantitative real-time PCR analysis revealed possible involvement of scallop SOX in various functions, including neuro-sensory cell differentiation, hematopoiesis, myogenesis and gametogenesis. This study represents the first systematic characterization of SOX gene family in Mollusca. It will assist in a better understanding of the evolution and function of SOX family in metazoans. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. The acoustic effects of guitar components

    Science.gov (United States)

    Inta, Ra; Gilet, Gerard; Smith, John; Wolfe, Joe

    2002-11-01

    The guitar is a complex oscillatory system made up of many vibrating components. Because of the variable mechanical properties of wood, it is not easy for makers to reproduce good instruments. Reproducibility can be improved if we know how the mechanical properties of the components interact to produce the sound of the completed instrument. Three steel-string acoustic guitars were constructed, in parallel and as similarly as possible, the only design difference being the timber used for the top-plates. Prior to construction, the Young's moduli, densities, and moisture contents of a selection of top-plate brace, neck, and bridge materials were measured and the most similar were retained for creating the three instruments. Transfer functions and Chladni modes of the top-plates were measured at seven stages of construction, and the radiation patterns and acoustic efficiencies of the finished instruments measured. The effects of brace scalloping and neck attachment systems are reported. These results, and the behavior of some simple systems, are compared with finite element simulations that include scalloped bracing and glue bonding. [Work supported by the Australian Research Council and Gilet Guitars, Australia.

  18. Shark predation on cephalopods in the Mexican and Ecuadorian Pacific Ocean

    Science.gov (United States)

    Galván-Magaña, Felipe; Polo-Silva, Carlos; Berenice Hernández-Aguilar, Sandra; Sandoval-Londoño, Alejandro; Ruth Ochoa-Díaz, Maria; Aguilar-Castro, Nallely; Castañeda-Suárez, David; Cabrera Chavez-Costa, Alejandra; Baigorrí-Santacruz, Álvaro; Eden Torres-Rojas, Yassir; Andrés Abitia-Cárdenas, Leonardo

    2013-10-01

    Pelagic predators such as sharks have been shown to be effective cephalopod samplers, because they have high consumption rates and swimming speeds. The stomach contents of these predators allow us to determine the distribution and abundance of cephalopods, considering the scarcity of biological information and the difficulty of catching squids and octopi using traditional methods. The silky shark (Carcharhinus falciformis), blue shark (Prionace glauca), scalloped hammerhead (Sphyrna lewini), smooth hammerhead (Sphyrna zygaena), pelagic thresher shark (Alopias pelagicus), and bigeye thresher shark (Alopias superciliosus) were caught off both coasts of Baja California Sur, Mexico, and in the Ecuadorian Pacific Ocean. Cephalopod sizes (mantle lengths, ML) were calculated based on the beak measurements to determine the size of cephalopods consumed by the sharks. We identified 21 cephalopod species based on beak items found in the shark stomachs. The most abundant cephalopods consumed by sharks in both areas were Dosidicus gigas, Ancistrocheirus lesueurii, Onychoteuthis banksii, Sthenoteuthis ovalaniensis, Argonauta spp., Abraliopsis affinis, and Mastigoteuthis dentata. The cephalopod's habitat provides information about the depth at which these sharks capture their prey. The blue shark feeds on cephalopods in epipelagic, mesopelagic, and bathypelagic waters; the silky shark feeds on cephalopods in epipelagic waters; and the scalloped hammerhead shark preys on cephalopods in neritic (bottom) and oceanic waters (epipelagic and mesopelagic). The pelagic thresher shark consumed epipelagic and neritic species; whereas the bigeye thresher shark feeds mainly on epipelagic and mesopelagic squids in Ecuadorian waters. The smooth hammerhead preys on epipelagic and mesopelagic squids off Mexico and Ecuador.

  19. Yki/YAP, Sd/TEAD and Hth/MEIS control tissue specification in the Drosophila eye disc epithelium.

    Directory of Open Access Journals (Sweden)

    Tianyi Zhang

    Full Text Available During animal development, accurate control of tissue specification and growth are critical to generate organisms of reproducible shape and size. The eye-antennal disc epithelium of Drosophila is a powerful model system to identify the signaling pathway and transcription factors that mediate and coordinate these processes. We show here that the Yorkie (Yki pathway plays a major role in tissue specification within the developing fly eye disc epithelium at a time when organ primordia and regional identity domains are specified. RNAi-mediated inactivation of Yki, or its partner Scalloped (Sd, or increased activity of the upstream negative regulators of Yki cause a dramatic reorganization of the eye disc fate map leading to specification of the entire disc epithelium into retina. On the contrary, constitutive expression of Yki suppresses eye formation in a Sd-dependent fashion. We also show that knockdown of the transcription factor Homothorax (Hth, known to partner Yki in some developmental contexts, also induces an ectopic retina domain, that Yki and Scalloped regulate Hth expression, and that the gain-of-function activity of Yki is partially dependent on Hth. Our results support a critical role for Yki- and its partners Sd and Hth--in shaping the fate map of the eye epithelium independently of its universal role as a regulator of proliferation and survival.

  20. Distribution of heavy metals in internal organs and tissues of Korean molluscan shellfish and potential risk to human health.

    Science.gov (United States)

    Mok, Jong Soo; Kwon, Ji Young; Son, Kwang Tae; Choi, Woo Seok; Kim, Poong Ho; Lee, Tae Seek; Kim, Ji Hoe

    2015-09-01

    Molluscan shellfish (gastropods and bivalves) were collected from major fish markets on the Korean coast and analyzed for mercury by direct Hg analyzer and for other metals, such as cadmium, lead, chromium, silver, nickel, copper and zinc, using inductively coupled plasma mass spectrometry. Distribution of heavy metals in muscles, internal organs and whole tissues were determined and a potential risk assessment was conducted to evaluate their hazard for human consumption. Heavy metals were accumulated significantly higher (P metals (Cd, Pb, and Hg) in all internal-organ samples were above the regulatory limit of Korea and the mean level in whole tissue samples of the selected gastropod species, bay scallop and comb pen shell, exceeded the limit (except in a few cases). The sum of the estimated dietary intake of Cd, Pb and Hg for each part of all tested species accounted for 1.59-16.94, 0.02-0.36, and 0.07-0.16% respectively, of the provisional tolerable daily intake adopted by the Joint FAO/WHO Expert Committee on Food Additives. The hazard index for each part of gastropods and bivalves was below 1.0, however, the maximum HI for internal organs of all analysed species was quite high (0.71). These results suggest that consumption of flesh after removing the internal organs of some molluscan shellfish (all gastropod species, bay scallop and comb pen shell) is a suitable way for reducing Cd exposure.

  1. TONDU (TDU), a novel human protein related to the product of vestigial (vg) gene of Drosophila melanogaster interacts with vertebrate TEF factors and substitutes for Vg function in wing formation.

    Science.gov (United States)

    Vaudin, P; Delanoue, R; Davidson, I; Silber, J; Zider, A

    1999-11-01

    The mammalian TEF and the Drosophila scalloped genes belong to a conserved family of transcriptional factors that possesses a TEA/ATTS DNA-binding domain. Transcriptional activation by these proteins likely requires interactions with specific coactivators. In Drosophila, Scalloped (Sd) interacts with Vestigial (Vg) to form a complex, which binds DNA through the Sd TEA/ATTS domain. The Sd-Vg heterodimer is a key regulator of wing development, which directly controls several target genes and is able to induce wing outgrowth when ectopically expressed. Here we show that Vg contains two distinct transcriptional activation domains, suggesting that the function of Vg is to mediate transcriptional activation by Sd. By expressing a chimeric GAL4-Sd protein in Drosophila, we found that the transcriptional activity of the Vg-Sd heterodimer is negatively regulated at the AP and DV boundary of the wing disc. We also identify a novel human protein, TONDU, which contains a short domain homologous to the domain of Vg required for interaction with Sd. We show that TONDU specifically interacts with a domain conserved in all the mammalian TEF factors. Expression of TDU in Drosophila by means of the UAS-GAL4 system shows that this human protein can substitute for Vg in wing formation. We propose that TDU is a specific coactivator for the mammalian TEFs.

  2. Trophic ecology of sharks in the mid-east pacific ocean inferred from stable isotopes

    Science.gov (United States)

    Li, Yunkai; Gong, Yi; Chen, Xinjun; Dai, Xiaojie; Zhu, Jiangfeng

    2013-11-01

    As apex predators, sharks are of ecological and conservation importance in marine ecosystems. In this study, trophic positions of sharks were estimated using stable isotope ratios of carbon and nitrogen for five representative species caught by the Chinese longline fleet in the mid-east Pacific, i.e., the blue shark (Prionace glauca), the bigeye thresher shark (Alopias superciliosus), the silky shark (Carcharhinus falciformis), the scalloped hammerhead (Sphyrna lewini), and the oceanic whitetip shark (Carcharhinus longimanus). Of these species, oceanic whitetip shark has the lowest trophic level and mean δ15N value (3.9 and 14.93‰ ± 0.84‰), whereas bigeye thresher shark has the highest level/values (4.5 and 17.02‰ ± 1.21‰, respectively). The bigeye thresher shark has significantly higher δ15N value than other shark species, indicating its higher trophic position. The blue shark and oceanic whitetip shark has significantly higher δ13C values than bigeye thresher shark, silky shark and scalloped hammerhead, possibly due to different diets and/or living habitats. The stable isotope data and stomach content data are highly consistent, suggesting that stable isotope analysis supplements traditional feeding ecology study of sharks, and thus contributes to understanding their trophic linkage.

  3. CATCH COMPOSITION AND SOME BIOLOGICAL ASPECTS OF SHARKS IN WESTERN SUMATERA WATERS OF INDONESIA

    Directory of Open Access Journals (Sweden)

    Dharmadi Dharmadi

    2017-01-01

    Full Text Available This study was conducted in western Sumatera and since October 2013 to June 2014. The sampling locations in Banda Aceh and Sibolga-North Sumatera which were the largest base of fisheries in western Sumatera region. Shark landing recorded by enumerators was used  as sampling data daily . This research aim to describ sex ratio, size composition, catch composition of sharks, and length at first maturity. In Banda Aceh, the sharks as target fish collected by  sorting the bycatch from tuna longlines and tuna handlines. In Sibolga, sharks  is bycatch from fish net, bottom gillnet and purse seine. Overall, there were 20 species of shark caught in west Indian Ocean and landed at those fish landing sites, dominated by Spot tail shark (23% and Silky shark (13%, whereas Hammerhead shark contributed about 10% and  Oceanic whitetip shark was only less than 1%. Almost of Spot tail shark, Silky shark, and Scalloped hammerhead that caught in that area were  immature, while for the almost part of Tiger shark and Pelagic thresher were  matured. The sex ratios for Spot tail shark, Silky shark, Tiger shark, Pelagic thresher, and Scalloped hammerhead caught and landed at Lampulo and Sibolga fish landing sites were not balance. The length at first maturity for Spot tail shark was Lm=87,1 cm and Lm = 213,2 cm total length for Tiger shark.

  4. Fine-needle aspiration study of cystic papillary thyroid carcinoma: Rare cytological findings

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    Maral Mokhtari

    2016-01-01

    Full Text Available Background: Cystic papillary thyroid carcinoma (CPTC is a variant of papillary carcinoma that has many mimickers in cytological grounds. Aim: To study the cytomorphologic features of CPTC and compare them to those of other cystic thyroid lesions using fine-needle aspiration cytology (FNAC. We also aimed to identify the cytomorphologic features that distinguish CPTC from other cystic thyroid lesions. Materials and Methods: Seventy-three cases of CPTC were included in the study. The cytomorphologic features of these cases were analyzed. The FNA smears of other thyroid lesions with cystic changes (300 colloid goiters, 290 adenomatoid nodules, 11 follicular neoplasms, and 9 hurtle cell neoplasm were also studied. Results: The smears in CPTC revealed isolated follicular cells, small groups of cells with scalloped margins, cell swirls, small clusters with a cartwheel pattern, papillary clusters, intranuclear inclusions, nuclear grooves, sticky colloid, intracellular colloids, psammoma bodies, multinucleated giant cells, and foamy and hemosiderin laden macrophages. Small groups of cells with scalloped borders, cellular swirls, and small clusters with a cartwheel pattern were seen in CPTC, but not in other cystic lesions. Interestingly, mesothelial-like cells and hemophagocytic cells were seen in five and three cases of CPTC, respectively, but not in other cystic lesions. Conclusion: Mesothelial-like cells and hemophagocytic cells were observed in five and three cases of CPTC, respectively. Similar finding have not been previously reported in the literature.

  5. Posterior approach for giant S1 neurofibroma in Von Recklinghausen's disease: Is total resection realistic?

    Science.gov (United States)

    Kumar, Ashish; Vinjamuri, Srinivas; Barada, Sahu P

    2013-10-01

    Bilateral sacral neurofibromas are uncommonly seen in neurofibromatosis type 1 (NF1) also known as Von Recklinghausen's disease. They often grow to enormous dimensions before detection owing to bone scalloping. Resections of "giant" S1 neurofibromas are difficult due to the limitations of operative window in sacrum and critical functions associated with S1 nerve root. We report a case of bilateral S1 neurofibromas in a patient of NF1 where she had a giant left-sided neurofibroma with extensive bone erosion and a small fusiform neurofibroma on the right side. The tumor was excised completely on the left and near totally on the right side via posterior approach. There were no postoperative neurological deficits and the patient recovered well. Usually, complete excision harbors the chances of postoperative neurological deficits due to the eloquence of the nerve root involved and complete resection without significant morbidity seems unrealistic. However, excision of giant ones may not result in grave deficits always if the patient is neurologically intact before surgery. Also, in selected patients, only posterior approach may suffice for giant neurofibromas with extensive bone scalloping and complete removal can be attempted successfully despite narrow corridors.

  6. Posterior approach for giant S1 neurofibroma in von Recklinghausen′s disease: Is total resection realistic?

    Directory of Open Access Journals (Sweden)

    Ashish Kumar

    2013-01-01

    Full Text Available Bilateral sacral neurofibromas are uncommonly seen in neurofibromatosis type 1 (NF1 also known as Von Recklinghausen′s disease. They often grow to enormous dimensions before detection owing to bone scalloping. Resections of "giant" S1 neurofibromas are difficult due to the limitations of operative window in sacrum and critical functions associated with S1 nerve root. We report a case of bilateral S1 neurofibromas in a patient of NF1 where she had a giant left-sided neurofibroma with extensive bone erosion and a small fusiform neurofibroma on the right side. The tumor was excised completely on the left and near totally on the right side via posterior approach. There were no postoperative neurological deficits and the patient recovered well. Usually, complete excision harbors the chances of postoperative neurological deficits due to the eloquence of the nerve root involved and complete resection without significant morbidity seems unrealistic. However, excision of giant ones may not result in grave deficits always if the patient is neurologically intact before surgery. Also, in selected patients, only posterior approach may suffice for giant neurofibromas with extensive bone scalloping and complete removal can be attempted successfully despite narrow corridors.

  7. Tempo-spatial variation of nutrient and chlorophyll- α concentrations from summer to winter in the Zhangzi Island Area (Northern Yellow Sea)

    Science.gov (United States)

    Yin, Jiehui; Zhao, Zengxia; Zhang, Guangtao; Wang, Shiwei; Wan, Aiyong

    2013-09-01

    Nutrient and Chlorophyll- a (Chl- a) concentrations were investigated monthly along three transects extending from a mariculture area to open waters around the Zhangzi Island area from July to December 2009. The objective of this study is to illustrate food availability to the bottom-sowed scallop Patinopecten yessoensis under the influences of the Yellow Sea Cold Water Mass (YSCWM), freshwater input and feedbacks of cultivated scallops. Significant thermal stratification was present in open waters from July to October, and salinity decreased in July and August in surface layers in the mariculture area. Nutrient concentrations increased with depth in both areas in summer, but were similar through water column in November and December. On average, nutrient increased from summer to autumn in all components except ammonia. Nutrient concentrations lower than the minimum thresholds for phytoplankton growth were present only in upper layers in summer, but stoichiometric nitrogen limitation existed in the entire investigation period. Column-averaged Chl- a concentration was lower in open waters than in mariculture area in all months. It increased significantly in mariculture area in August and October, and was less variable in open waters. Our results show that nutrients limitation to phytoplankton growth is present mainly in upper layer in association with stratification caused by YSCWM in summer. Freshwater input and upwelling of nutrients accumulated in YSCWM can stimulate phytoplankton production in mariculture area. Farming activities may change stoichiometric nutrient ratios but have less influence on Chl- a concentration.

  8. Role of shellfish hatchery as a reservoir of antimicrobial resistant bacteria.

    Science.gov (United States)

    Miranda, Claudio D; Rojas, Rodrigo; Garrido, Marcela; Geisse, Julieta; González, Gerardo

    2013-09-15

    The main aim of this study was to determine the occurrence of resistant bacteria in florfenicol-treated and untreated scallop larval cultures from a commercial hatchery and to characterize some selected florfenicol-resistant strains. Larval cultures from untreated and treated rearing tanks exhibited percentages of copiotrophic bacteria resistant to florfenicol ranging from 0.03% to 10.67% and 0.49-18.34%, respectively, whereas florfenicol resistance among oligotrophic bacteria varied from 1.44% to 35.50% and 3.62-95.71%, from untreated and treated larvae, respectively. Florfenicol resistant microbiota from reared scallop larvae mainly belonged to the Pseudomonas and Pseudoalteromonas genus and were mainly resistant to florfenicol, chloramphenicol, streptomycin and co-trimoxazole. This is the first study reporting antimicrobial resistant bacteria associated to a shellfish hatchery and the results suggest that a continuous surveillance of antimicrobial resistance even in absence of antibacterial therapy is urgently required to evaluate potential undesirable consequences on the surrounding environments. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. A study of ameloblastoma on the relationship between histopathologic patterns and radiographic characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyun Bae; You, Dong Soo [Dept. of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1992-08-15

    The purpose of this study was to evaluate the correlationship between histopathologic types of ameloblastoma and their radiographic appearance.The materials for this study consisted of 106 patients diagnosed as ameloblastoma both radiographically and histologically. The obtained results were as follows: 1. The incidence of ameloblastoma in male (60 cases, 56.6%) was slightly higher than that in female (46 cases, 43.4%). The average age was estimated as 30.7 years with a range from 6 to 76 years. The second decade revealed the highest rate. 2. 106 ameloblastomas were histopathologically classified as 36 uicystic, 28 plexiform, 20 follicular, 14 acanthomatous, 7 granular cell, and 1 basalcell ameloblastoma. 3. Unilocular, soap-bubble appearance and scalloped margin were the radiographic appearances frequently seen in unicystic ameloblastoma . The predominant radiographic appearance of plexiform ameloblastoma showed unilocular radiolucency with scalloped margin. 4. 19.8%, 21 cases of ameloblastoma in this study showed containing tooth in their tumor mass by radiography. 5. Root resorption occurred in 37 cases (34.9%) and tooth displacement in 7 cases (6.6%). Root resorption and tooth displacement occurred in same patient were 24 cases (22.6%). 6. Recurrence occurred in 21.7% and average year between initial treatment and recurrence were 2 years.

  10. Yki/YAP, Sd/TEAD and Hth/MEIS Control Tissue Specification in the Drosophila Eye Disc Epithelium

    Science.gov (United States)

    Pignoni, Francesca

    2011-01-01

    During animal development, accurate control of tissue specification and growth are critical to generate organisms of reproducible shape and size. The eye-antennal disc epithelium of Drosophila is a powerful model system to identify the signaling pathway and transcription factors that mediate and coordinate these processes. We show here that the Yorkie (Yki) pathway plays a major role in tissue specification within the developing fly eye disc epithelium at a time when organ primordia and regional identity domains are specified. RNAi-mediated inactivation of Yki, or its partner Scalloped (Sd), or increased activity of the upstream negative regulators of Yki cause a dramatic reorganization of the eye disc fate map leading to specification of the entire disc epithelium into retina. On the contrary, constitutive expression of Yki suppresses eye formation in a Sd-dependent fashion. We also show that knockdown of the transcription factor Homothorax (Hth), known to partner Yki in some developmental contexts, also induces an ectopic retina domain, that Yki and Scalloped regulate Hth expression, and that the gain-of-function activity of Yki is partially dependent on Hth. Our results support a critical role for Yki- and its partners Sd and Hth - in shaping the fate map of the eye epithelium independently of its universal role as a regulator of proliferation and survival. PMID:21811580

  11. The long-term impacts of fisheries on epifaunal assemblage function and structure, in a Special Area of Conservation

    Science.gov (United States)

    Strain, E. M. A.; Allcock, A. L.; Goodwin, C. E.; Maggs, C. A.; Picton, B. E.; Roberts, D.

    2012-01-01

    Fisheries can have profound effects on epifaunal community function and structure. We analysed the results from five dive surveys (1975-1976, 1980, 1983, 2003 and 2007), taken in a Special Area of Conservation, Strangford Lough, Northern Ireland before and after a ten year period of increased trawling activity between 1985 and 1995. There were no detectable differences in the species richness or taxonomic distinctiveness before (1975-1983) and after (2003-2007) this period. However, there was a shift in the epifaunal assemblage between the surveys in 1975-1983 and 2003-2007. In general, the slow-moving, or sessile, erect, filter-feeders were replaced by highly mobile, swimming, scavengers and predators. There were declines in the frequency of the fished bivalve Aequipecten opercularis and the non-fished bivalves Modiolus modiolus and Chlamys varia and some erect sessile invertebrates between the surveys in 1975-1983 and 2003-2007. In contrast, there were increases in the frequency of the fished and reseeded bivalves Pecten maximus and Ostrea edulis, the fished crabs Cancer pagurus and Necora puber and the non-fished sea stars Asterias rubens, Crossaster papposus and Henricia oculata between the surveys in 1975-1983 and 2003-2007. We suggest that these shifts could be directly and indirectly attributed to the long-term impacts of trawl fishing gear, although increases in the supply of discarded bait and influxes of sediment may also have contributed to changes in the frequency of some taxa. These results suggest that despite their limitations, historical surveys and repeat sampling over long periods can help to elucidate the inferred patterns in the epifaunal community. The use of commercial fishing gear was banned from two areas in Strangford Lough in 2011, making it a model ecosystem for assessing the long-term recovery of the epifaunal community from the impacts of mobile and pot fishing gear.

  12. Evidence for long-term uplift on the Canary Islands from emergent Mio Pliocene littoral deposits

    Science.gov (United States)

    Meco, Joaquín; Scaillet, Stéphane; Guillou, Hervé; Lomoschitz, Alejandro; Carlos Carracedo, Juan; Ballester, Javier; Betancort, Juan-Francisco; Cilleros, Antonio

    2007-06-01

    Several islands in the Canarian archipelago show marine deposits with identical fossil faunas, which are generally assigned to different glacioeustatic marine episodes: mainly Pleistocene episodes in Lanzarote and Fuerteventura, and Mio-Pliocene ones in Gran Canaria. Three fossil species ( Saccostrea chili, Nerita emiliana and Strombus coronatus) characterize all the marine deposits from southern Lanzarote, to the west and south of Fuerteventura and northeast of Gran Canaria. Three other species ( Ancilla glandiformis, Rothpletzia rudista and Siderastraea miocenica) confirm the chronostratigraphic attribution of these deposits. Other more occasional fossils (as Chlamys latissima, Isognomon soldanii and Clypeaster aegyptiacus) fit an upper Miocene and lower Pliocene age. This agrees with new K/Ar ages obtained from pillow lavas emplaced into the marine deposits (ca. 4.1 Ma in Gran Canaria, ca. 4.8 Ma in Fuerteventura) and from underlying (ca. 9.3 Ma in Gran Canaria) or overlying (ca. 9.8 Ma in Lanzarote) lava flows. The marine deposits are eroded but large continuous segments are preserved sloping gently towards the coast. Variations in the highest and the lowest elevations of the deposits apsl (above present sea level) indicate post-depositional uplift movements. Glacioeustatic causes are unlikely to be responsible for these variations on the basis of the coastal location of the deposits and their equatorial fauna characteristic of Mio-Pliocene corals. Differential uplift of the deposits across the archipelago is argued to result from the progressive seaward tilting of the islands along the insular volcanic trail marking the westward migration of hot spot head since 20 Ma. Successive westward accretion of younger volcanic edifices resulted in increasing lithostatic load of the crust with progressive (diachronous) tilting of the older edifices and their palaeo-shorelines marked by past coastal deposits.

  13. Ice-Accretion Test Results for Three Large-Scale Swept-Wing Models in the NASA Icing Research Tunnel

    Science.gov (United States)

    Broeren, Andy P.; Potapczuk, Mark G.; Lee, Sam; Malone, Adam M.; Paul, Bernard P., Jr.; Woodard, Brian S.

    2016-01-01

    Icing simulation tools and computational fluid dynamics codes are reaching levels of maturity such that they are being proposed by manufacturers for use in certification of aircraft for flight in icing conditions with increasingly less reliance on natural-icing flight testing and icing-wind-tunnel testing. Sufficient high-quality data to evaluate the performance of these tools is not currently available. The objective of this work was to generate a database of ice-accretion geometry that can be used for development and validation of icing simulation tools as well as for aerodynamic testing. Three large-scale swept wing models were built and tested at the NASA Glenn Icing Research Tunnel (IRT). The models represented the Inboard (20 percent semispan), Midspan (64 percent semispan) and Outboard stations (83 percent semispan) of a wing based upon a 65 percent scale version of the Common Research Model (CRM). The IRT models utilized a hybrid design that maintained the full-scale leading-edge geometry with a truncated afterbody and flap. The models were instrumented with surface pressure taps in order to acquire sufficient aerodynamic data to verify the hybrid model design capability to simulate the full-scale wing section. A series of ice-accretion tests were conducted over a range of total temperatures from -23.8 to -1.4 C with all other conditions held constant. The results showed the changing ice-accretion morphology from rime ice at the colder temperatures to highly 3-D scallop ice in the range of -11.2 to -6.3 C. Warmer temperatures generated highly 3-D ice accretion with glaze ice characteristics. The results indicated that the general scallop ice morphology was similar for all three models. Icing results were documented for limited parametric variations in angle of attack, drop size and cloud liquid-water content (LWC). The effect of velocity on ice accretion was documented for the Midspan and Outboard models for a limited number of test cases. The data suggest

  14. Densidad, crecimiento y supervivencia de juveniles de Lyropecten (Nodipecten nodosus (Pteroida: Pectinidae en cultivo suspendido en el Golfo de Cariaco, Venezuela

    Directory of Open Access Journals (Sweden)

    Vanessa Acosta

    2000-12-01

    Full Text Available El efecto de la densidad sobre el crecimiento y la supervivencia de juveniles del pectínido Lyropecten nodosus se estudió en condiciones de cultivo intermedio en el Golfo de Cariaco, Estado Sucre, Venezuela (diciembre 93 - julio 94. Se evaluaron seis densidades de siembra (7, 15, 30, 60, 125 y 250 ejemplares/cesta con una longitud y una masa seca inicial de 9.4 + 0.18 mm y 0.007 + 0.0026 g, respectivamente. Los juveniles fueron colocados en cestas japonesas "pearl nets" y posteriormente suspendidas en un "long line" a 8 m de profundidad. Los patrones de crecimiento en cada uno de los compartimientos del soma fueron similares, pero con magnitudes diferentes e inversamente proporcionales a la densidades de cultivo; sin embargo, la supervivencia no fue afectada significativamente, sugiriendo que la competencia intraespecífica de los organismos en cultivo provocó un estrés notable, aunque insuficiente para causar mortalidad. Los resultados y estrategias proyectadas para el cultivo intermedio de L. nodosus sugieren un procedimiento de disminución de la densidad de organismos a través de desdobles sucesivos en un período de cultivo de seis meses obteniendo tallas cercanas a los 50 mm para comenzar el cultivo de engorde.The effect of culture density on growth and survival of juveniles was studied in the scallop Lyropecten nodosus with intermediate hanging cultures in Golfo de Cariaco, Sucre state, Venezuela, from December 1993 to July 1994. Six spat-densities (7, 15, 30, 60, 125 and 250 scallops/nets were evaluated. The initial shell height and dry mass tissue were 9.4 + 0.18 mm and 0.007 + 0.0026 g, respectively. The specimens were placed into pearl nets and suspended in a long line at 8 m depth. Growth patterns of somatic tissue were similar, but with different magnitudes and inverse proportionality to culture density. No effect of density was observed on survival. These results suggest that intraspecific competition of cultivated scallops

  15. Loss of the Drosophila cell polarity regulator Scribbled promotes epithelial tissue overgrowth and cooperation with oncogenic Ras-Raf through impaired Hippo pathway signaling

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    Grusche Felix A

    2011-09-01

    Full Text Available Abstract Background Epithelial neoplasias are associated with alterations in cell polarity and excessive cell proliferation, yet how these neoplastic properties are related to one another is still poorly understood. The study of Drosophila genes that function as neoplastic tumor suppressors by regulating both of these properties has significant potential to clarify this relationship. Results Here we show in Drosophila that loss of Scribbled (Scrib, a cell polarity regulator and neoplastic tumor suppressor, results in impaired Hippo pathway signaling in the epithelial tissues of both the eye and wing imaginal disc. scrib mutant tissue overgrowth, but not the loss of cell polarity, is dependent upon defective Hippo signaling and can be rescued by knockdown of either the TEAD/TEF family transcription factor Scalloped or the transcriptional coactivator Yorkie in the eye disc, or reducing levels of Yorkie in the wing disc. Furthermore, loss of Scrib sensitizes tissue to transformation by oncogenic Ras-Raf signaling, and Yorkie-Scalloped activity is required to promote this cooperative tumor overgrowth. The inhibition of Hippo signaling in scrib mutant eye disc clones is not dependent upon JNK activity, but can be significantly rescued by reducing aPKC kinase activity, and ectopic aPKC activity is sufficient to impair Hippo signaling in the eye disc, even when JNK signaling is blocked. In contrast, warts mutant overgrowth does not require aPKC activity. Moreover, reducing endogenous levels of aPKC or increasing Scrib or Lethal giant larvae levels does not promote increased Hippo signaling, suggesting that aPKC activity is not normally rate limiting for Hippo pathway activity. Epistasis experiments suggest that Hippo pathway inhibition in scrib mutants occurs, at least in part, downstream or in parallel to both the Expanded and Fat arms of Hippo pathway regulation. Conclusions Loss of Scrib promotes Yorkie/Scalloped-dependent epithelial tissue

  16. The ultrastructure of the dental tissues in dentinogenesis imperfecta in man.

    Science.gov (United States)

    Wright, J T; Gantt, D G

    1985-01-01

    Eight primary incisors obtained from a child with dentinogenesis imperfecta (DI) type II were examined histologically using light microscopy and scanning electron microscopy. In both the DI and control teeth, large dentinal canals were observed along the midline of the crown distributed mesial-distally and coursing towards the pulp. Variably-structured mantle dentine was seen in the DI teeth ranging from tubular to virtually atubular. Enamel separation occurred at the dentine-enamel junction despite apparently normal scalloping. In the enamel, fractures occurred along accentuated striae of Retzius where ultrastructurally there was prism bending and discontinuity. The structure of DI teeth probably results from a structural or regulatory protein abnormality and irregular epithelial-mesenchymal interaction. The combined influence of these factors appears to cause variable histologic appearances and rates of tissue deposition.

  17. Temporal resolution and spectral sensitivity of the visual system of three coastal shark species from different light environments.

    Science.gov (United States)

    McComb, D Michelle; Frank, Tamara M; Hueter, Robert E; Kajiura, Stephen M

    2010-01-01

    Visual temporal resolution and scotopic spectral sensitivity of three coastal shark species (bonnethead Sphyrna tiburo, scalloped hammerhead Sphyrna lewini, and blacknose shark Carcharhinus acronotus) were investigated by electroretinogram. Temporal resolution was quantified under photopic and scotopic conditions using response waveform dynamics and maximum critical flicker-fusion frequency (CFF). Photopic CFF(max) was significantly higher than scotopic CFF(max) in all species. The bonnethead had the shortest photoreceptor response latency time (23.5 ms) and the highest CFF(max) (31 Hz), suggesting that its eyes are adapted for a bright photic environment. In contrast, the blacknose had the longest response latency time (34.8 ms) and lowest CFF(max) (16 Hz), indicating its eyes are adapted for a dimmer environment or nocturnal lifestyle. Scotopic spectral sensitivity revealed maximum peaks (480 nm) in the bonnethead and blacknose sharks that correlated with environmental spectra measured during twilight, which is a biologically relevant period of heightened predation.

  18. A New Method to Calibrate Attachment Angles of Data Loggers in Swimming Sharks

    Science.gov (United States)

    Kawatsu, Shizuka; Sato, Katsufumi; Watanabe, Yuuki; Hyodo, Susumu; Breves, Jason P.; Fox, Bradley K.; Grau, E. Gordon; Miyazaki, Nobuyuki

    2009-12-01

    Recently, animal-borne accelerometers have been used to record the pitch angle of aquatic animals during swimming. When evaluating pitch angle, it is necessary to consider a discrepancy between the angle of an accelerometer and the long axis of an animal. In this study, we attached accelerometers to 17 free-ranging scalloped hammerhead shark ( Sphyrna lewini) pups from Kaneohe Bay, Hawaii. Although there are methods to calibrate attachment angles of accelerometers, we confirmed that previous methods were not applicable for hammerhead pups. According to raw data, some sharks ascended with a negative angle, which differs from tank observations of captive sharks. In turn, we developed a new method to account for this discrepancy in swimming sharks by estimating the attachment angle from the relationship between vertical speed (m/s) and pitch angle obtained by each accelerometer. The new method can be utilized for field observation of a wide range of species.

  19. A comparison of the heart and muscle total lipid and fatty acid profiles of nine large shark species from the east coast of South Africa.

    Science.gov (United States)

    Davidson, Bruce; Sidell, Jonathan; Rhodes, Jeffrey; Cliff, Geremy

    2011-03-01

    We have assessed the fatty acid profiles of the hearts and different muscle tissues from nine large shark species (Carcharhinus limbatus (blacktip), Carcharhinus obscurus (dusky), Carcharhinus brevipinna (spinner), Carcharhinus leucas (Zambezi/bull), Galeocerdo cuvier (tiger), Sphyrna lewini (scalloped hammerhead), Sphyrna zygaena (smooth hammerhead), Carcharodon carcharias (great white) and Carcharias taurus (raggedtooth/grey nurse/sand tiger)) found off the east coast of South Africa. While there was generally little variation between the species, all species showed profiles rich in both n6 and n3 polyunsaturated fatty acids compared to terrestrial commercial meats that have low n3. Thus, utilizing skeletal muscle tissues from sharks caught as part of the bycatch when fishing for teleosts would avoid unnecessary wastage of a potentially valuable resource, with all the possible health benefits of high quality protein combined with balanced polyunsaturates, although contamination with high levels of metabolic wastes, such as urea, may be a negative consideration.

  20. Ventricle morphology in pelagic elasmobranch fishes.

    Science.gov (United States)

    Emery, S H; Mangano, C; Randazzo, V

    1985-01-01

    Ventricle weights of the warm-bodied great white shark, Atlantic shortfin mako, and the common thresher shark (the latter presumed to be warm-bodied) are similar to those of ectothermic blue sharks, sandbar sharks, dusky sharks, tiger sharks and scalloped hammerhead sharks. Ventricle muscularity, as estimated by the ratio of cortical to spongy layer thickness, is almost twice as great in the former three species than in the latter elasmobranchs. Measurements of ventricular volumes suggest that the ventricles of the great white, Atlantic shortfin mako and common thresher sharks are better adapted to respond to demands for increases in cardiac output via increased heartbeat frequency in comparison with ectothermic species of shark.

  1. Spindle Cell Liposarcoma – A Rare Tumour Occurring at a Rare Site?

    Directory of Open Access Journals (Sweden)

    Varuna Mallya

    2017-10-01

    Full Text Available Lipomatous tumours are the most common type of soft tissue neoplasms with liposarcomas being the most common soft tissue sarcomas. Spindle cell liposarcoma is the most recent addition to this group and is characterized by a lipocytic and spindled component both showing atypia. Lipoblasts with their characteristic scalloped nuclei are found in the spindled areas. These tumours show CD34 positivity. Arising in the head and neck and soft tissues of the extremities, this tumour was described for the first time in 1994. Very few cases are reported in the literature. The present case emphasizes the fact that this tumour should be considered as a possible diagnosis in tissues histologically showing a good admixture of adipocytic and spindled cells.

  2. Current status of adsorbent for metal ions with radiation grafting and crosslinking techniques

    Science.gov (United States)

    Seko, Noriaki; Tamada, Masao; Yoshii, Fumio

    2005-07-01

    Removal of toxic metals from streaming water and ground water is important task to preserve environment. Radiation processing of grafting and crosslinking can synthesis adsorbent having high performances. Graft adsorbent can be synthesized by using the conventional polymer like polyethylene having variety shapes such as membrane, cloth, and fiber. Especially, the obtained fibrous adsorbent has 100 times higher rate of adsorption than that of commercialized resin. Fibrous adsorbent of iminodiacetate was applied to the removal of cadmium from the scallop waste. Furthermore, the amidoxime adsorbent is useful for recovery of rare metals such as uranium and vanadium in seawater. Novel fibrous adsorption for arsenic was synthesized by direct grafting of phosphoric monomer and following zirconium-loading. Crosslinked natural polymers like carboxymethyl chitin-chitosan in the paste-like state are applicable for the metal adsorbent. This adsorbent can be biodegraded after usage.

  3. Dynamic friction modelling in heat exchanger tube simulations

    Energy Technology Data Exchange (ETDEWEB)

    Tan, X.; Rogers, R.J. [Univ. of New Brunswick, Fredericton, New Brunswick (Canada). Dept. of Mechanical Engineering

    1996-12-01

    A force-balance friction model has been developed to describe dynamic friction phenomena in multi-degree of freedom vibration systems and validated for a two degree-of-freedom (2dof) lumped mass vibration system. It has been implemented into VIBIC, a finite element code for the vibration of beams with intermittent contact, to improve the prediction of tube wear rate in the simulation of shell-and-tube heat exchangers. The friction model has been tailored for VIBIC for various kinds of supports: circular, semi-circular scallop-bar, and arbitrary flat-bar supports. Simulations for single fuel pin vibration have been compared with experimental data on wear work rate for different test conditions, gaps and preloads.

  4. Fuzzy reasoning rule-based system for handling lace pattern distortion

    Science.gov (United States)

    Sherkat, Nasser; Shih, Chi-Hsien V.; Thomas, Peter D.

    1995-03-01

    Much progress has been made in using computer vision to automate the process of lace scalloping. Because the material is flexible, dealing with stretch due to mechanical feed produces a challenge. The vision system has to work with many different patterns and sizes of lace as well as tolerating misalignment. A Fuzzy Reasoning Rule-based technique is employed in order to overcome the problems of material flexibility. Several experiments have been carried out using lace patterns of varying complexity. All cutting paths across the patterns were successfully found. Experimental results indicate that this method can correctly detect the river path in different lace patterns, and cope with lace stretch as well as distortion.

  5. Detection of viruses and virus-like particles in four species of wild and farmed bivalve molluscs in Alaska, U.S.A., from 1987 to 2009.

    Science.gov (United States)

    Meyers, Theodore R; Burton, Tamara; Evans, Wally; Starkey, Norman

    2009-12-22

    The U.S. Alaska Department of Fish and Game has regulatory oversight of the mariculture industry that is partially administered through a statewide shellfish health policy. Possession and transport of bivalve molluscs require development of indigenous pathogen histories from diagnostic examinations of wild and farmed populations. These examinations have resulted in the detection of various infectious agents and parasites including viruses: an aquareovirus and aquabirna-like virus isolated by fish cell culture, and papilloma- or polyoma- and herpes-like virus particles within bivalve cell intranuclear inclusion bodies observed by electron microscopy. This study summarizes these results in samples examined from 1987 to 2009 and is the first description of poikilothermic viruses from Alaskan waters isolated from or observed within the tissues of 4 species of bivalve molluscs: geoduck clam Panope abrupta, native littleneck clam Protothaca staminea, purple-hinged rock scallop Crassadoma gigantea and Pacific oyster Crassostrea gigas.

  6. Late Cenozoic Bryozoa from diamictites of Cape Lamb, Vega Island, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Adamonis Susana

    2015-12-01

    Full Text Available Bryozoans were found in upper Cenozoic diamictite debris that crops out at the southwestern tip of Cape Lamb, Vega Island. The diamictite is the youngest deposit on the island and richly composed of foraminifers, brachiopods and scallops. The foraminifera assemblage recovered from the Cape Lamb diamictite and 87Sr/86Sr isotopic age obtained from the pectinid Adamussium colbecki in the nearby locality of Terrapin indicates a Pleistocene age for this deposit. The main goal of this contribution is to present a bryozoan assemblage of Microporella stenoporta Hayward et Taylor, Hippothoa flagellum Manzoni, Ellisina antarctica (Kluge, Micropora notialis Hayward et Ryland and an indeterminate crisiid constituting the first record of these bryozoan taxa in Cenozoic diamictites of the Antarctic Peninsula.

  7. Subacute Staphylococcus epidermidis Bacterial Endocarditis Complicated by Mitral-Aortic Intervalvular Fibrosa Pseudoaneurysm

    Directory of Open Access Journals (Sweden)

    Diane Elegino-Steffens

    2012-01-01

    Full Text Available The patient is a 75-year-old man with a history significant for hypertension and congestive heart failure who underwent a bioprosthetic aortic valve replacement secondary to acute onset of aortic insufficiency. Cultures of the native valve were positive for Staphylococcus epidermidis sensitive to nafcillin and intravenous cefazolin was initiated. On postoperative day 24, he developed acute decompensated heart failure. A transesophageal echocardiogram demonstrated a structurally abnormal mitral valve with severe regurgitation, anterior and posterior leaflet vegetations, and scallop prolapse. There was also evidence of a mitral-aortic intervalvular fibrosa pseudoaneurysm (P-MAIF with systolic expansion and flow within the aneurysm. Antibiotic treatment was changed from cefazolin to vancomycin for presumed development of methicillin-resistant Staphylococcus. He subsequently underwent a bioprosthetic mitral valve replacement and has restoration of health without sequella. This case highlights the development of a P-MAIF as a rare complication of both aortic or mitral valve replacement and infective endocarditis.

  8. Transgenerational exposure of North Atlantic bivalves to ocean acidification renders offspring more vulnerable to low pH and additional stressors.

    Science.gov (United States)

    Griffith, Andrew W; Gobler, Christopher J

    2017-09-12

    While early life-stage marine bivalves are vulnerable to ocean acidification, effects over successive generations are poorly characterized. The objective of this work was to assess the transgenerational effects of ocean acidification on two species of North Atlantic bivalve shellfish, Mercenaria mercenaria and Argopecten irradians. Adults of both species were subjected to high and low pCO 2 conditions during gametogenesis. Resultant larvae were exposed to low and ambient pH conditions in addition to multiple, additional stressors including thermal stress, food-limitation, and exposure to a harmful alga. There were no indications of transgenerational acclimation to ocean acidification during experiments. Offspring of elevated pCO 2 -treatment adults were significantly more vulnerable to acidification as well as the additional stressors. Our results suggest that clams and scallops are unlikely to acclimate to ocean acidification over short time scales and that as coastal oceans continue to acidify, negative effects on these populations may become compounded and more severe.

  9. First record of Cymatium keenae Beu, 1970 (Mollusca: Ranellidae) from Antofagasta Bay, northern Chile, in connection with El Niño events

    Science.gov (United States)

    Ashton, Tom; Riascos, Jose M.; Pacheco, Aldo

    2008-03-01

    Cymatium ( Monoplex) keenae Beu, 1970, the neopolitan triton, is a Ranellidae predator distributed in tropical and subtropical waters. In this study we report this species for the first time in Antofagasta Bay, northern Chile. Adult specimens have been found since June 2003 at depths ranging from 5 to 15 m in La Rinconada Marine Reserve (23°28'18″S, 70°30'46″W) in Antofagasta Bay, near a scallop farming facility. The present findings clearly extend the geographic range of C. keenae, which previously had been reported from La Paz, Gulf of California (Mexico) to Galápagos Islands (Ecuador) in the SE Pacific. Previous evidence strongly suggests that the intrusion of this tropical immigrant can be related to warm El Niño episodes. We analyze the key role of the oceanographic characteristics of Antofagasta Bay as potential temporal refuge for this species.

  10. Unusual Mediastinal Dumbbell Tumor Mimicking an Aggressive Malignancy

    Directory of Open Access Journals (Sweden)

    Sanyal Kumar

    2012-01-01

    Full Text Available Hydatid cyst is known to affect all possible anatomical locations of the human body. However, the mediastinal localization is extremely rare. This benign, commonly asymptomatic and incidentally detected disease, at times may simulate an aggressive malignancy by its potential to cause osseous destruction and intraspinal extension. A young female, farmer by occupation, presented with complaints of left chest pain and monoparesis of the left lower limb. Radiograph followed by computed tomography (CT of the chest demonstrated a cystic mass within the posterior mediastinum, eroding and scalloping overlying ribs and extending into the spinal canal by causing destruction of adjoining vertebra, and assuming a dumbbell shape. The serology was positive for echinococcosis. The patient underwent surgery and the postoperative histopathology confirmed the diagnosis of hydatid cyst. The patient recovered with no complications or recurrence. Hydatid cyst should always be considered in the differential diagnosis of mediastinal cystic lesions, however aggressive the lessions may appear.

  11. Transbrachial branch cannulation during Zenith fenestrated endovascular aortic aneurysm repair using a robotically guided body-floss technique

    Directory of Open Access Journals (Sweden)

    Sukgu M. Han, MD

    2016-09-01

    Full Text Available Caudal angulation and stenosis of the renal arteries pose significant challenges in branch cannulation during the standard fenestrated endovascular aortic aneurysm repair (FEVAR. We describe an alternative technique of branch cannulation during FEVAR in a patient with a 6.5-cm juxtarenal abdominal aortic aneurysm, renal artery stenosis, and bilateral caudally oriented renal arteries. A brachiofemoral or “body-floss” access was established by traversing the top scallop. The brachial sheath was deflected toward the target fenestration using a steerable robotic femoral sheath, enabling transbrachial cannulation of the downgoing target renal artery. Postoperatively, the patient was discharged without complications. Steerable sheath-guided body-floss technique may facilitate cannulation of severely downgoing branch vessels during FEVAR.

  12. Molecular and pathological characterization of Fusarium solani species complex infection in the head and lateral line system of Sphyrna lewini.

    Science.gov (United States)

    Pirarat, Nopadon; Sahatrakul, Komsil; Lacharoje, Sitthichok; Lombardini, Eric; Chansue, Nantarika; Techangamsuwan, Somporn

    2016-08-09

    A severe fungal infection affecting the head and lateral line system was diagnosed in 7 captive scalloped hammerhead sharks Sphyrna lewini in an aquarium in Thailand. Extensive and severe necrotizing cellulitis was consistently observed microscopically along the cephalic and lateral line canals in conjunction with positive fungal cultures for Fusarium sp. Molecular phylogenetic analysis was performed from 3 isolates based on the nucleotide sequences containing internally transcribed spacer (ITS) and a portion of 5.8S and 28S rDNA. The fungus was highly homologous (100%) and closely related to F. solani species complex 2 (FSSC 2), which belongs to Clade 3 of the FSSC. Our results illustrate the histopathological findings and expand upon our knowledge of the prevalence of invasive fusariosis in the head and lateral line system of hammerhead sharks.

  13. Adhesive arachnoiditis causing cauda equina syndrome in ankylosing spondylitis: CT and MRI demonstration of dural calcification and a dorsal dural diverticulum

    Energy Technology Data Exchange (ETDEWEB)

    Bilgen, I.G.; Yunten, N.; Ustun, E.E. [Ege Univ., Dept. of Radiology, Izmir (Turkey); Oksel, F.; Gumusdis, G. [Ege Univ., Dept. of Rheumatology, Izmir (Turkey)

    1999-07-01

    We present the radiological features of a 42-years-old man with long-standing inactive ankylosing spondylitis (AS), demonstrating that arachnoiditis is a cause of a cauda equina syndrome (CES) in this disease. CT showed a dorsal arachnoid diverticulum causing scalloped erosion of the laminae, and punctate and curvilinear dural calcification. MRI revealed adhesion and convergence of the cauda equina dorsally into the arachnoid pouch, causing the dural sca to appear empty canal. To the best of our knowledge, dural calcification on CT is a new finding in AS, which may be related to the CES. Our findings support the hyopthesis that chronic adhesive arachnoiditis with subsequent loss of meningeal elasticity may be the main cause of CES in AS. (orig.)

  14. Stafne cyst: Report of two unusual cases with review

    Directory of Open Access Journals (Sweden)

    Manoharan G V Murali Gopika

    2016-01-01

    Full Text Available Stafne cyst, named after Edward Stafne, was first described in 1942 when he noticed asymptomatic radiolucent cavities in intraoral radiographs of 35 different patients. It is usually a well-defined, round, ovoid or occasionally lobulated radiolucency of size 1–3 cm typically located in the submandibular gland fossa. In this paper, we present two cases of Stafne cyst, one with an unusual presentation having trapezoid-shaped radiolucency with scalloped margin involving the inferior border of the mandible and another with the usual presentation. In both the cases, diagnosis was based on clinical and radiological features alone without any surgical exploration. With the condition remaining static throughout the follow-up period, it is proven that noninvasive diagnostic radiography such as computed tomography scan with three-dimensional reconstruction and cone beam computed tomography can be very helpful for the definite diagnosis of Stafne cyst, rather than invasive procedures.

  15. The rock abrasion record at Gale Crater: Mars Science Laboratory results from Bradbury Landing to Rocknest

    Science.gov (United States)

    Bridges, N.T.; Calef, F.J.; Hallett, B.W.; Herkenhoff, Kenneth E.; Lanza, N.L.; Le Mouélic, S.; Newman, C.E.; Blaney, D.L.; de Pablo, M.A.; Kocurek, G.A.; Langevin, Y.; Lewis, K.W.; Mangold, N.; Maurice, S.; Meslin, P.-Y.; Pinet, P.; Renno, N.O.; Rice, CM.S.; Richardson, M.E.; Sautter, V.; Sletten, R.S.; Wiens, R.C.; Yingst, R.A.

    2014-01-01

    Ventifacts, rocks abraded by wind-borne particles, are found in Gale Crater, Mars. In the eastward drive from “Bradbury Landing” to “Rocknest,” they account for about half of the float and outcrop seen by Curiosity's cameras. Many are faceted and exhibit abrasion textures found at a range of scales, from submillimeter lineations to centimeter-scale facets, scallops, flutes, and grooves. The drive path geometry in the first 100 sols of the mission emphasized the identification of abrasion facets and textures formed by westerly flow. This upwind direction is inconsistent with predictions based on models and the orientation of regional dunes, suggesting that these ventifact features formed from very rare high-speed winds. The absence of active sand and evidence for deflation in the area indicates that most of the ventifacts are fossil features experiencing little abrasion today.

  16. Rippled beam free electron Laser Amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Carlsten, Bruce E.

    1998-04-21

    A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a T{sub 0n} mode. A waveguide defines an axial centerline and . A solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

  17. TEVAR and covering the celiac artery. Is it safe or not?

    DEFF Research Database (Denmark)

    Falkenberg, Morten; Lönn, Lars Birger; Schroeder, Torben Veith

    2010-01-01

    in these patients. If the distal sealing zone above the celiac axis is too short, several endovascular alternatives are possible; hybrid procedures with TEVAR and open by-pass to the celiac artery, custom made stent-grafts with scallop or fenestration for the celiac artery, or intentional coverage of the celiac...... artery. In the latter case, adequate collateral supply to the upper gastrointestinal tract is crucial. Collateral arteries joining the celiac and the superior mesenteric arteries are well characterized in patients with chronic celiac stenosis or occlusion. Are these collateral pathways sufficient also...... for sudden iatrogenic closure of the celiac artery? By performing a preoperative angiography of the superior mesenteric artery with temporary balloon occlusion of the celiac artery, collateral capacity between the two vessels can be tested in advance. Exact positioning of the distal end of a large thoracic...

  18. Non-chromate deoxidation of AA2024-T3: Sodium bromate nitric acid (20 60 °C)

    Science.gov (United States)

    Harvey, T. G.; Hughes, A. E.; Hardin, S. G.; Nikpour, T.; Toh, S. K.; Boag, A.; McCulloch, D.; Horne, M.

    2008-03-01

    The effect of a non-chromate deoxidiser (bromate-nitric acid) on AA2024-T3 has been examined by SEM, TEM/EELS and XPS. At low temperatures (20 °C) the deoxidiser removed all intermetallics but had little effect on the surface oxide. At 40 °C, attack on the intermetallics was again extensive but there was also evidence of attack on the surface oxide covering the matrix after 10 min of immersion, leaving a roughened porous oxide. At 60 °C, removal of intermetallics was complete and longer immersion times resulted in a characteristic scalloped structure across the surface which became more pronounced with increasing immersion time.

  19. A New Method to Calibrate Attachment Angles of Data Loggers in Swimming Sharks

    Directory of Open Access Journals (Sweden)

    Shizuka Kawatsu

    2010-01-01

    Full Text Available Recently, animal-borne accelerometers have been used to record the pitch angle of aquatic animals during swimming. When evaluating pitch angle, it is necessary to consider a discrepancy between the angle of an accelerometer and the long axis of an animal. In this study, we attached accelerometers to 17 free-ranging scalloped hammerhead shark (Sphyrna lewini pups from Kaneohe Bay, Hawaii. Although there are methods to calibrate attachment angles of accelerometers, we confirmed that previous methods were not applicable for hammerhead pups. According to raw data, some sharks ascended with a negative angle, which differs from tank observations of captive sharks. In turn, we developed a new method to account for this discrepancy in swimming sharks by estimating the attachment angle from the relationship between vertical speed (m/s and pitch angle obtained by each accelerometer. The new method can be utilized for field observation of a wide range of species.

  20. First data on three bivalve species exposed to an intra-harbour polymetallic contamination (La Rochelle, France).

    Science.gov (United States)

    Breitwieser, Marine; Viricel, Amélia; Churlaud, Carine; Guillot, Benoit; Martin, Elie; Stenger, Pierre-Louis; Huet, Valérie; Fontanaud, Angélique; Thomas-Guyon, Hélène

    2017-09-01

    Evaluating diffuse sediment contamination in the environment is a major concern with the aim of reaching a good chemical and ecological state of the littoral zone. In this study the risks of chronic chemical contamination and consequences in the bivalves Crassostrea gigas, Mytilus sp. and Mimachlamys varia were evaluated in coastal environments. The objective here was to understand the anthropological phenomena that affect the functioning of the marina of La Rochelle (semi-closed environment). Harbours seeking ecomanagement accreditations (such as the international reference ISO 14001) constitute zones of interest to implement biomonitoring studies. The biological effects of chemical pollution in the Marina of La Rochelle were studied to develop a multi-biomarker biomonitoring approach on specific marine species of this site. Moreover, a genetic (DNA barcoding) approach was applied to validate the species identity of collected bivalves. Of the three species tested the scallop, M. varia, was the most sensitive to metal exposure. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. TWENTY YEARS OF RESEARCH AND SHELLFISH FARMING IN THE MOUTH OF THE KRKA RIVER

    Directory of Open Access Journals (Sweden)

    Drago Maguš

    2001-09-01

    Full Text Available This work shows a short review of activities in the twenty years of research and controlled shellfish farming in the brackish waters of the mouth of the Krka River. Legislative background for granting concessions was especially emphasized as well as problems limiting aquaculture development in this extremely productive area where, according to the latest facts, the production of sea organisms could witness a manifold increase without any substantial disturbance of the ecologic stability of the aquatorium. The analysis of the further farming increase suggests controlled mussel and oyster culturing thus making a polyculture with fish; as well as a secondary culturing of scallops and cockles within the mussel and/or oyster polyculture process in deeper water layers which have not been exploited up to now.

  2. Intermetallic Growth Retardation with the Addition of Graphene in the Sn-3.5Ag Lead-free Solder

    Science.gov (United States)

    Mayappan, R.; Salleh, A.

    2017-06-01

    In this study, the effect of 0.07 wt.% graphene nanosheets (GNSs) on the thermal, microstructure and intermetallic compounds (IMC) growth kinetics were investigated. Experimental results showed that addition of GNSs to the Sn-3.5Ag solder alloy slightly increased the melting temperature. Scanning electron microscope (SEM) micrograph revealed that with the addition of GNSs has transformed the morphologies of the interfacial IMC from scalloped to more planar-shaped after isothermal aging for 500 hours. Growth kinetics calculations show that the k value was reduced from 9.08 × 10-14 cm2/s to 5.73 × 10-14 cm2/s with the addition of graphene. Thereby, it indicates that the addition of GNSs suppressed the growth of the IMC layers hence retarded the IMC’s growth.

  3. Propeamussiidae, Inoceramidae, and other Bivalvia from the Lower Cretaceous Puez Formation (Valanginian–Cenomanian; Dolomites, South Tyrol, Italy)☆

    Science.gov (United States)

    Schneider, Simon; Crampton, James S.; Lukeneder, Alexander

    2013-01-01

    A bivalve assemblage from the Lower Cretaceous Puez Formation at the type locality, Piz de Puez (Dolomites, South Tyrol, northern Italy) is described. Given the large amount of sedimentary rock screened during the course of this study, the <50 bivalves examined here, although occurring in very low abundance, are considered to represent a reasonably comprehensive sample. The assemblage provides insight into an autochthonous, Mesozoic, deep-water bivalve community, which was dominated by glass scallops. Two species are described as new, Parvamussium pizpuezense n. sp. and the giant P. mordsdrum n. sp. Presumably, they lived as epifaunal-reclining carnivores and preyed on various meiofauna, occupying a similar ecologic niche as their modern counterparts. Scarce epifaunal, suspension-feeding Inoceramidae entered only by occasional recruitment of larvae into an environment that is inferred to have been characterised by low levels of suspended nutrients. PMID:27087719

  4. Propeamussiidae, Inoceramidae, and other Bivalvia from the Lower Cretaceous Puez Formation (Valanginian-Cenomanian; Dolomites, South Tyrol, Italy).

    Science.gov (United States)

    Schneider, Simon; Crampton, James S; Lukeneder, Alexander

    2013-11-01

    A bivalve assemblage from the Lower Cretaceous Puez Formation at the type locality, Piz de Puez (Dolomites, South Tyrol, northern Italy) is described. Given the large amount of sedimentary rock screened during the course of this study, the <50 bivalves examined here, although occurring in very low abundance, are considered to represent a reasonably comprehensive sample. The assemblage provides insight into an autochthonous, Mesozoic, deep-water bivalve community, which was dominated by glass scallops. Two species are described as new, Parvamussium pizpuezense n. sp. and the giant P. mordsdrum n. sp. Presumably, they lived as epifaunal-reclining carnivores and preyed on various meiofauna, occupying a similar ecologic niche as their modern counterparts. Scarce epifaunal, suspension-feeding Inoceramidae entered only by occasional recruitment of larvae into an environment that is inferred to have been characterised by low levels of suspended nutrients.

  5. Grade 4 spondylolisthesis of the L5 vertebra associated with dural ectasia in neurofibromatosis.

    Science.gov (United States)

    Modi, H N; Srinivasalu, S; Suh, S W; Yang, J H

    2009-08-01

    Spondylolisthesis associated with neurofibromatosis is rare, and only 12 cases have been reported so far. However, only one report of grade 4 spondylolisthesis with neurofibromatosis has been reported in the literature. A 15-year-old boy with neurofibromatosis was admitted for back pain and neurological claudication. Radiograph showed grade 4 spondylolisthesis of the L5 vertebra with scalloping of the L4-L5 vertebrae. L4-L5 laminectomy, reduction, L3-S1 posterior instrumentation and fusion were performed. The reduction of the spondylisthesis was done entirely from the posterior approach using pedicle screws. Radiography at four months showed a broken S1 screw with a loss of reduction. The patient was re-operated on, to provide additional stability with pelvic fixation. He was pain-free with a good fusion at the two-year follow-up. Adequate posterior stabilisation with fusion gives good results in grade 4 spondylolisthesis associated with neurofibromatosis and dural ectasia.

  6. Mixing effectiveness test of an exhaust gas mixer in a high bypass turbofan at altitude

    Science.gov (United States)

    Cullom, R. R.; Burkardt, L. A.; Bobula, G. A.

    1981-01-01

    Thermal mixing effectiveness characteristics of an eighteen lobe, scalloped and unscalloped, partial, forced mixer were measured in a high-bypass turbofan engine. Data were also obtained without the mixer installed, i.e. free mixing. Tests were conducted at four combinations of simulated flight conditions from 0.3 to 0.8 Mach number and from 6,096 meters (20,000 ft) to 13,715 m (45,000 ft) altitude. Mixing chamber lengths of L/D = 0.52 and 0.65 were tested. For this range of test conditions and mixer configurations the forced mixing effectiveness varied from 59 to 68 percent. Values of mixing effectiveness and total pressure loss were calculated from temperature and pressure data obtained at the mixer inlet and exhaust nozzle exit.

  7. New observations on frustule morphology of Eupodiscus radiatus Bailey and Fryxelliella floridana Prasad

    Directory of Open Access Journals (Sweden)

    Fernandes L. F.

    2003-01-01

    Full Text Available A study of the diatoms Eupodiscus radiatus Bailey and Fryxelliella floridana Prasad, mainly focussing on the mantle and cingulum, provided new morphological information. In E. radiatus dendritic structures and two types of a palisade-like structure fixed to silica rings were found on the lower valve mantle. Cingulum presented 1-3 bands with areolae arranged in decussate rows. Furthermore, the pars interior of the valvocopula is fimbriate; and the external openings of the rimoportulae are located along the rim of the scalloped extension. The valvocopula of F. floridana is open and its copula is ligulate. Both bands possess poroid areolae similar in size to the cribral pores on the valve face. The genus Eupodiscus is compared to Fryxelliella, based on material sampled in estuaries of Southern Brazil.

  8. Effect of Flux onto Intermetallic Compound Formation and Growth

    Directory of Open Access Journals (Sweden)

    Idris Siti Rabiatull Aisha

    2016-01-01

    Full Text Available In this study, the effect of different composition of no-clean flux onto intermetallic compound (IMC formation and growth was investigated. The solder joint between Sn-3Ag-0.5Cu solder alloy and printed circuit board (PCB was made through reflow soldering. They were further aged at 125°C and 150°C for up to 1000 hours. Results showed that fluxes significantly affect the IMC thickness and growth. In addition, during aging, the scallop and columnar morphology of IMC changed to a more planar type for both type of flux during isothermal aging. It was observed that the growth behavior of IMC was closely related to initial soldering condition.

  9. Mitral valve mechanics following posterior leaflet patch augmentation

    DEFF Research Database (Denmark)

    Rahmani, Azadeh; Rasmussen, Ann Qvist; Hønge, Jesper Langhoff

    2013-01-01

    Background and aim of the study: Attention towards the optimization of mitral valve repair methods is increasing. Patch augmentation is one strategy used to treat functional ischemic mitral regurgitation (FIMR). The study aim was to investigate the force balance changes in specific chordae...... tendineae emanating from the posterior papillary muscle in a FIMR-simulated valve, following posterior leaflet patch augmentation. Methods: Mitral valves were obtained from 12 pigs (body weight 80 kg). An in vitro test set-up simulating the left ventricle was used to hold the valves. The left ventricular...... pressure was regulated with water to simulate different static pressures during valve closure. A standardized oval pericardial patch (17 × 29 mm) was introduced into the posterior leaflet from mid P2 to the end of the P3 scallop. Dedicated miniature transducers were used to record the forces exerted...

  10. Poor-data and data-poor species stock assessment using a Bayesian hierarchical approach.

    Science.gov (United States)

    Jiao, Yan; Cortés, Enric; Andrews, Kate; Guo, Feng

    2011-10-01

    Appropriate inference for stocks or species with low-quality data (poor data) or limited data (data poor) is extremely important. Hierarchical Bayesian methods are especially applicable to small-area, small-sample-size estimation problems because they allow poor-data species to borrow strength from species with good-quality data. We used a hammerhead shark complex as an example to investigate the advantages of using hierarchical Bayesian models in assessing the status of poor-data and data-poor exploited species. The hammerhead shark complex (Sphyrna spp.) along the Atlantic and Gulf of Mexico coasts of the United States is composed of three species: the scalloped hammerhead (S. lewini), the great hammerhead (S. mokarran), and the smooth hammerhead (S. zygaena) sharks. The scalloped hammerhead comprises 70-80% of the catch and has catch and relative abundance data of good quality, whereas great and smooth hammerheads have relative abundance indices that are both limited and of low quality presumably because of low stock density and limited sampling. Four hierarchical Bayesian state-space surplus production models were developed to simulate variability in population growth rates, carrying capacity, and catchability of the species. The results from the hierarchical Bayesian models were considerably more robust than those of the nonhierarchical models. The hierarchical Bayesian approach represents an intermediate strategy between traditional models that assume different population parameters for each species and those that assume all species share identical parameters. Use of the hierarchical Bayesian approach is suggested for future hammerhead shark stock assessments and for modeling fish complexes with species-specific data, because the poor-data species can borrow strength from the species with good data, making the estimation more stable and robust.

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

    Science.gov (United States)

    Herschlag, Gregory; Miller, Laura

    2011-09-21

    The Scallop theorem states that reciprocal methods of locomotion, such as jet propulsion or paddling, will not work in Stokes flow (Reynolds number=0). In nature the effective limit of jet propulsion is still in the range where inertial forces are significant. It appears that almost all animals that use jet propulsion swim at Reynolds numbers (Re) of about 5 or more. Juvenile squid and octopods hatch from the egg already swimming in this inertial regime. Juvenile jellyfish, or ephyrae, break off from polyps swimming at Re greater than 5. Many other organisms, such as scallops, rarely swim at Re less than 100. The limitations of jet propulsion at intermediate Re is explored here using the immersed boundary method to solve the 2D Navier-Stokes equations coupled to the motion of a simplified jellyfish. The contraction and expansion kinematics are prescribed, but the forward and backward swimming motions of the idealized jellyfish are emergent properties determined by the resulting fluid dynamics. Simulations are performed for both an oblate bell shape using a paddling mode of swimming and a prolate bell shape using jet propulsion. Average forward velocities and work put into the system are calculated for Re between 1 and 320. The results show that forward velocities rapidly decay with decreasing Re for all bell shapes when Reswimming velocities and vortex separation patterns for the model prolate agree with those observed in Nemopsis bachei. The forward swimming velocities of the model oblate jellyfish after two pulse cycles are comparable to those reported for Aurelia aurita, but discrepancies are observed in the vortex dynamics between when the 2D model oblate jellyfish and the organism. This discrepancy is likely due to a combination of the differences between the 3D reality of the jellyfish and the 2D simplification, as well as the rigidity of the time varying geometry imposed by the idealized model. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. A study of the traumatic bone cyst

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Kyung Ran; Park, Won Kyl; Ko, Jae Kyeung; Kim, Young Jin [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Chosun University, Kyangju (Korea, Republic of)

    1997-08-15

    Traumatic bone cyst is a pathologic cavity that is not lined with epithelium. It is, therefore, not a true cyst. It may be a normal variant rather than a disease process. The etiology of the condition is unknown. This condition is occurred widely ranging ages(2 to 75 years), however, most are found during the second decade of life. Radiographically, this condition is radiolucent lesion with well-defined outline, scalloping of superior margins. Cyst enucleation and curettage is the treatment of choice. The authors compared and analyzed the clinicoradiologic features of the five cases of traumatic bone cyst, diagnosed at the Dental college hospital in Chosun University, Kwangju, Korea. The five cases were shown the followed results; 1. 3 cases occurred in second decade of life and no significant sex differences (M:F, 2:3) All cases occurred in mandible. 2. Two patients complained symptoms, but three cases had no symptom with encountering during routine examination. 3. In 3 of 5 cases, teeth vitality existed except one tooth and no checking of teeth vitality in two cases. 4. All cases didn't have any accurate trauma history, but one case was in orthodontic treatment, another case was postextraction site area. 5. Radiologically, 'scalloping appearance' were evident in all cases; in 3 cases, multilocular tendency and only one case seen intact mandibular canal image. 6. Histologically, all section showed bone trabeculae with ballistic activity, 2 cases showed no epithelial lining, and other 2 cases were seen inflammatory cell infiltration in edematous tissue. 7. Surgical intervention (curettage) was that treatment of choice.

  13. MethylRAD: a simple and scalable method for genome-wide DNA methylation profiling using methylation-dependent restriction enzymes.

    Science.gov (United States)

    Wang, Shi; Lv, Jia; Zhang, Lingling; Dou, Jinzhuang; Sun, Yan; Li, Xue; Fu, Xiaoteng; Dou, Huaiqian; Mao, Junxia; Hu, Xiaoli; Bao, Zhenmin

    2015-11-01

    Characterization of dynamic DNA methylomes in diverse phylogenetic groups has attracted growing interest for a better understanding of the evolution of DNA methylation as well as its function and biological significance in eukaryotes. Sequencing-based methods are promising in fulfilling this task. However, none of the currently available methods offers the 'perfect solution', and they have limitations that prevent their application in the less studied phylogenetic groups. The recently discovered Mrr-like enzymes are appealing for new method development, owing to their ability to collect 32-bp methylated DNA fragments from the whole genome for high-throughput sequencing. Here, we have developed a simple and scalable DNA methylation profiling method (called MethylRAD) using Mrr-like enzymes. MethylRAD allows for de novo (reference-free) methylation analysis, extremely low DNA input (e.g. 1 ng) and adjustment of tag density, all of which are still unattainable for most widely used methylation profiling methods such as RRBS and MeDIP. We performed extensive analyses to validate the power and accuracy of our method in both model (plant Arabidopsis thaliana) and non-model (scallop Patinopecten yessoensis) species. We further demonstrated its great utility in identification of a gene (LPCAT1) that is potentially crucial for carotenoid accumulation in scallop adductor muscle. MethylRAD has several advantages over existing tools and fills a void in the current epigenomic toolkit by providing a universal tool that can be used for diverse research applications, e.g. from model to non-model species, from ordinary to precious samples and from small to large genomes, but at an affordable cost. © 2015 The Authors.

  14. Kinetics of Isothermal Reactive Diffusion Between Solid Cu and Liquid Sn

    Science.gov (United States)

    O, M.; Suzuki, T.; Kajihara, M.

    2017-09-01

    The Cu/Sn system is one of the most fundamental and important metallic systems for solder joints in electric devices. To realize reliable solder joints, information on reactive diffusion at the solder joint is very important. In the present study, we experimentally investigated the kinetics of the reactive diffusion between solid Cu and liquid Sn using semi-infinite Cu/Sn diffusion couples prepared by an isothermal bonding technique. Isothermal annealing of the diffusion couple was conducted in the temperature range of 533-603 K for various times up to 172.8 ks (48 h). Using annealing, an intermetallic layer composed of Cu6Sn5 with scallop morphology and Cu3Sn with rather uniform thickness is formed at the original Cu/Sn interface in the diffusion couple. The growth of the Cu6Sn5 scallop occurs much more quickly than that of the Cu3Sn layer and thus predominates in the overall growth of the intermetallic layer. This tendency becomes more remarkable at lower annealing temperatures. The total thickness of the intermetallic layer is proportional to a power function of the annealing time, and the exponent of the power function is close to unity at all the annealing temperatures. This means that volume diffusion controls the intermetallic growth and the morphology of the Cu6Sn5/Sn interface influences the rate-controlling process. Adopting a mean value of 0.99 for the exponent, we obtain a value of 26 kJ/mol for the activation enthalpy of the intermetallic growth.

  15. The substantial first impact of bottom fishing on rare biodiversity hotspots: a dilemma for evidence-based conservation.

    Science.gov (United States)

    Cook, Robert; Fariñas-Franco, Jose M; Gell, Fiona R; Holt, Rohan H F; Holt, Terry; Lindenbaum, Charles; Porter, Joanne S; Seed, Ray; Skates, Lucie R; Stringell, Thomas B; Sanderson, William G

    2013-01-01

    This study describes the impact of the first passage of two types of bottom-towed fishing gear on rare protected shellfish-reefs formed by the horse mussel Modiolus modiolus (L.). One of the study sites was trawled and the other was scallop-dredged. Divers collected HD video imagery of epifauna from quadrats at the two study sites and directed infaunal samples from one site. The total number of epifaunal organisms was significantly reduced following a single pass of a trawl (90%) or scallop dredge (59%), as was the diversity of the associated community and the total number of M. modiolus at the trawled site. At both sites declines in anthozoans, hydrozoans, bivalves, echinoderms and ascidians accounted for most of the change. A year later, no recovery was evident at the trawled site and significantly fewer infaunal taxa (polychaetes, malacostracans, bivalves and ophuroids) were recorded in the trawl track. The severity of the two types of impact reflected the undisturbed status of the habitats compared to previous studies. As a 'priority habitat' the nature of the impacts described on M. modiolus communities are important to the development of conservation management policy and indicators of condition in Marine Protected Areas (EU Habitats Directive) as well as indicators of 'Good Environmental Status' under the European Union Marine Strategy Framework Directive. Conservation managers are under pressure to support decisions with good quality evidence. Elsewhere, indirect studies have shown declines of M. modiolus biogenic communities in fishing grounds. However, given the protected status of the rare habitat, premeditated demonstration of direct impact is unethical or illegal in Marine Protected Areas. This study therefore provides a unique opportunity to investigate the impact from fishing gear whilst at the same time reflecting on the dilemma of evidence-based conservation management.

  16. The substantial first impact of bottom fishing on rare biodiversity hotspots: a dilemma for evidence-based conservation.

    Directory of Open Access Journals (Sweden)

    Robert Cook

    Full Text Available This study describes the impact of the first passage of two types of bottom-towed fishing gear on rare protected shellfish-reefs formed by the horse mussel Modiolus modiolus (L.. One of the study sites was trawled and the other was scallop-dredged. Divers collected HD video imagery of epifauna from quadrats at the two study sites and directed infaunal samples from one site. The total number of epifaunal organisms was significantly reduced following a single pass of a trawl (90% or scallop dredge (59%, as was the diversity of the associated community and the total number of M. modiolus at the trawled site. At both sites declines in anthozoans, hydrozoans, bivalves, echinoderms and ascidians accounted for most of the change. A year later, no recovery was evident at the trawled site and significantly fewer infaunal taxa (polychaetes, malacostracans, bivalves and ophuroids were recorded in the trawl track. The severity of the two types of impact reflected the undisturbed status of the habitats compared to previous studies. As a 'priority habitat' the nature of the impacts described on M. modiolus communities are important to the development of conservation management policy and indicators of condition in Marine Protected Areas (EU Habitats Directive as well as indicators of 'Good Environmental Status' under the European Union Marine Strategy Framework Directive. Conservation managers are under pressure to support decisions with good quality evidence. Elsewhere, indirect studies have shown declines of M. modiolus biogenic communities in fishing grounds. However, given the protected status of the rare habitat, premeditated demonstration of direct impact is unethical or illegal in Marine Protected Areas. This study therefore provides a unique opportunity to investigate the impact from fishing gear whilst at the same time reflecting on the dilemma of evidence-based conservation management.

  17. Imaging of the jaw cysts with a dental CT software program : distinction of odontogenic keratocysts from other cysts

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Man; Shin, Sang Hoon; Lee, Won Hoon; Oh, Kyu Hyen; Jung, Hak Young; Lee, Young Hwan; Sung, Nak Kwan; Jung, Duck Soo; Kim, Ok Dong [Catholic Univ. of Taegu-Hyosung School of Medicine, Taegu (Korea, Republic of)

    1997-05-01

    To evaluate the usefulness of a dental CT software program in the assessment of jaw cysts and in the differentiation of odontogenic keratocysts and other cysts. Seventeen patients with proven jaw cysts(8 maxillae and 9 mandibles) were evaluated with a dental CT sofware program for location, locularity, the presence or absence of marginal scallping, and height to length ratio. For the delineation of involvement or displace-ment of neurovascular bundles, cortical erosion, perforation or expansion, and tooth root resorption by the jaw cysts, images from this program were compared to conventional images. Seventeen lesions icomprised 15 odontogenic cysts (five odontogenic keratocysts, five radicular, three residual and two dentigerous cysts) and two non-odontogenic cysts (one nasopalatine duct cyst and one postoperative maxillary cyst). Images of jaw cysts obtained with the dental CT software program delineated much more clearly than conventional images the status of neurovascular bundle and cortical bone, but there was no clear difference between the two modalities in delineating tooth root erosion. Dental CT findings of five mandibular odontogenic keratocysts were scalloped margin in all, mandibular ramus involvement in four, height to length ratio below 60% in four ,and multilocularity in two. The findings of the other 12 cysts (eight maxillae and four mandibles) were unilocularity in all, smooth inner margin in ten, height to length ratio below 60% in only two, and ramus involvement in none. A dental CT software program is an improved imaging modality for assessing jaw cysts;and findings which tend to indicate odontogenic keratocysts are marginal scalloping, mandibular ramus involvement, prominent spread along the marrow space and multilocularity.

  18. Genetic differentiation in relation to marine landscape in a broadcast-spawning bivalve mollusc (Placopecten magellanicus).

    Science.gov (United States)

    Kenchington, E L; Patwary, M U; Zouros, E; Bird, C J

    2006-06-01

    Marine bivalves are sessile or sedentary as adults but have planktonic larvae which can potentially disperse over large distances. Consequently larval transport is expected to play a prominent role in facilitating gene flow and determining population structure. The sea scallop (Placopecten magellanicus) is a dioecious species with high fecundity, broadcast spawning and a c. 30-day planktonic larval stage, yet it forms discrete populations or 'beds' which have significantly different dynamics and characteristics. We analysed variation at six microsatellite loci in 12 locations throughout the geographic range of the species from Newfoundland, Canada, to New Jersey, USA. Significant differentiation was present and the maximum pairwise theta value, between one of the Newfoundland samples in the north and a sample from the southern portion of the range, was high at 0.061. Other proximate pairs of samples had no detectable genetic differentiation. Mantel tests indicated a significant isolation by distance, but only when one of the populations was excluded. A landscape genetic approach was used to detect areas of low gene flow using a joint analysis of spatial and genetic information. The two major putative barriers inferred by Monmonier's algorithm were then used to define regions for an analysis of molecular variance (amova). That analysis showed a significant but low percentage (1.2%) of the variation to be partitioned among regions, negligible variation among populations within regions, and the majority of the variance distributed between individuals within populations. Prominent currents were concordant with the demarcation of the regions, while a novel approach of using particle tracking software to mimic scallop larval dispersal was employed to interpret within-region genetic patterns.

  19. Giant cell tumors of the tendon sheath may present radiologically as intrinsic osseous lesions

    Energy Technology Data Exchange (ETDEWEB)

    Schepper, A.M. de; Bloem, J.L. [Leiden University Medical Center, Department of Radiology, Albinusdreef 2, P.O. Box 9600, RC Leiden (Netherlands); Hogendoorn, P.C.W. [Leiden University Medical Center, Department of Pathology, Albinusdreef 2, P.O. Box 9600, RC Leiden (Netherlands)

    2007-02-15

    The purpose of this study was to explain radiographic features of giant cell tumors of the tendon sheath (GCTTS), in particular, osseous extension, by correlating imaging findings with histology in order to increase the accuracy of radiological diagnosis. In a series of 200 consecutive osseous (pseudo) tumors of the hand, on radiography, six patients presented with an intrinsic osseous lesion caused by a histologically confirmed neighboring GCTTS. Available radiographs, computed tomography (CT), and contrast-enhanced magnetic resonance (MR) images were correlated with histology. Radiography showed osseous lesions consisting of well-defined cortical defects in four (one of whom also demonstrated cortical scalloping) and a slightly expansile, well-defined osteolytic lesion in two patients. MR obtained in four patients showed the extraosseous tumor invading/eroding bone and causing cortical scalloping (three and one patients, respectively). Extension depicted on MR was confirmed on the two available resection specimens. All lesions were polylobular (cauliflower or mushroom like) and neighbored tendon sheaths. Dense collagen and hemosiderin-loaded macrophages explained the high CT attenuation and the low MR signal intensity on T2-weighted images that was observed in all four MR and in all two CT scans. The high density of proliferative capillaries explained the marked enhancement observed in all four patients with gadolinium (Gd)-chelate-enhanced MR imaging. GCTTS is a soft tissue (pseudo) tumor that may invade bone and as a consequence mimick an intrinsic osseous lesion on radiographs. In such cases, specific MR and CT features that can be explained by histological findings can be used to suggest the correct diagnosis. (orig.)

  20. Kinetics of Isothermal Reactive Diffusion Between Solid Cu and Liquid Sn

    Science.gov (United States)

    O, M.; Suzuki, T.; Kajihara, M.

    2018-01-01

    The Cu/Sn system is one of the most fundamental and important metallic systems for solder joints in electric devices. To realize reliable solder joints, information on reactive diffusion at the solder joint is very important. In the present study, we experimentally investigated the kinetics of the reactive diffusion between solid Cu and liquid Sn using semi-infinite Cu/Sn diffusion couples prepared by an isothermal bonding technique. Isothermal annealing of the diffusion couple was conducted in the temperature range of 533-603 K for various times up to 172.8 ks (48 h). Using annealing, an intermetallic layer composed of Cu6Sn5 with scallop morphology and Cu3Sn with rather uniform thickness is formed at the original Cu/Sn interface in the diffusion couple. The growth of the Cu6Sn5 scallop occurs much more quickly than that of the Cu3Sn layer and thus predominates in the overall growth of the intermetallic layer. This tendency becomes more remarkable at lower annealing temperatures. The total thickness of the intermetallic layer is proportional to a power function of the annealing time, and the exponent of the power function is close to unity at all the annealing temperatures. This means that volume diffusion controls the intermetallic growth and the morphology of the Cu6Sn5/Sn interface influences the rate-controlling process. Adopting a mean value of 0.99 for the exponent, we obtain a value of 26 kJ/mol for the activation enthalpy of the intermetallic growth.

  1. Comparative study of Hippo pathway genes in cellular conveyor belts of a ctenophore and a cnidarian

    Directory of Open Access Journals (Sweden)

    Alicia Coste

    2016-02-01

    Full Text Available Abstract Background The Hippo pathway regulates growth rate and organ size in fly and mouse, notably through control of cell proliferation. Molecular interactions at the heart of this pathway are known to have originated in the unicellular ancestry of metazoans. They notably involve a cascade of phosphorylations triggered by the kinase Hippo, with subsequent nuclear to cytoplasmic shift of Yorkie localisation, preventing its binding to the transcription factor Scalloped, thereby silencing proliferation genes. There are few comparative expression data of Hippo pathway genes in non-model animal species and notably none in non-bilaterian phyla. Results All core Hippo pathway genes could be retrieved from the ctenophore Pleurobrachia pileus and the hydrozoan cnidarian Clytia hemisphaerica, with the important exception of Yorkie in ctenophore. Expression study of the Hippo, Salvador and Scalloped genes in tentacle “cellular conveyor belts” of these two organisms revealed striking differences. In P. pileus, their transcripts were detected in areas where undifferentiated progenitors intensely proliferate and where expression of cyclins B and D was also seen. In C. hemisphaerica, these three genes and Yorkie are expressed not only in the proliferating but also in the differentiation zone of the tentacle bulb and in mature tentacle cells. However, using an antibody designed against the C. hemiphaerica Yorkie protein, we show in two distinct cell lineages of the medusa that Yorkie localisation is predominantly nuclear in areas of active cell proliferation and mainly cytoplasmic elsewhere. Conclusions This is the first evidence of nucleocytoplasmic Yorkie shift in association with the arrest of cell proliferation in a cnidarian, strongly evoking the cell division-promoting role of this protein and its inhibition by the activated Hippo pathway in bilaterian models. Our results furthermore highlight important differences in terms of deployment and

  2. Comparative study of Hippo pathway genes in cellular conveyor belts of a ctenophore and a cnidarian.

    Science.gov (United States)

    Coste, Alicia; Jager, Muriel; Chambon, Jean-Philippe; Manuel, Michaël

    2016-01-01

    The Hippo pathway regulates growth rate and organ size in fly and mouse, notably through control of cell proliferation. Molecular interactions at the heart of this pathway are known to have originated in the unicellular ancestry of metazoans. They notably involve a cascade of phosphorylations triggered by the kinase Hippo, with subsequent nuclear to cytoplasmic shift of Yorkie localisation, preventing its binding to the transcription factor Scalloped, thereby silencing proliferation genes. There are few comparative expression data of Hippo pathway genes in non-model animal species and notably none in non-bilaterian phyla. All core Hippo pathway genes could be retrieved from the ctenophore Pleurobrachia pileus and the hydrozoan cnidarian Clytia hemisphaerica, with the important exception of Yorkie in ctenophore. Expression study of the Hippo, Salvador and Scalloped genes in tentacle "cellular conveyor belts" of these two organisms revealed striking differences. In P. pileus, their transcripts were detected in areas where undifferentiated progenitors intensely proliferate and where expression of cyclins B and D was also seen. In C. hemisphaerica, these three genes and Yorkie are expressed not only in the proliferating but also in the differentiation zone of the tentacle bulb and in mature tentacle cells. However, using an antibody designed against the C. hemiphaerica Yorkie protein, we show in two distinct cell lineages of the medusa that Yorkie localisation is predominantly nuclear in areas of active cell proliferation and mainly cytoplasmic elsewhere. This is the first evidence of nucleocytoplasmic Yorkie shift in association with the arrest of cell proliferation in a cnidarian, strongly evoking the cell division-promoting role of this protein and its inhibition by the activated Hippo pathway in bilaterian models. Our results furthermore highlight important differences in terms of deployment and regulation of Hippo pathway genes between cnidarians and ctenophores.

  3. The occurrence of domoic acid linked to a toxic diatom bloom in a new potential vector: the tunicate Pyura chilensis (piure).

    Science.gov (United States)

    López-Rivera, Américo; Pinto, Maricela; Insinilla, Andrea; Suárez Isla, Benjamín; Uribe, Eduardo; Alvarez, Gonzalo; Lehane, Mary; Furey, Ambrose; James, Kevin J

    2009-11-01

    The tunicate Pyura chilensis (Molina, 1782); Phylum Chordata; Subphylum Urochordata; Class Ascidiacea, common local name "piure" or sea squirt; a filter-feeder (plankton and suspended particles) sessile species; may play an important role in monitoring domoic acid (DA) the principal toxic component of Amnesic Shellfish Poisoning (ASP). Significant DA concentrations have been determined in tunicate samples, collected during a recent ASP outbreak in Bahía Inglesa, an important scallop (Argopecten purpuratus) farming area. Several infaunal species were tested for the presence of DA, in addition to the usual scallop monitoring programme. DA was found at sub-toxic levels in filtering bivalves such as mussels (Mytilus chilensis), large mussels (Aulacomya ater) and clams (Protothaca thaca) (6.4, 5.4 and 4.7 microg DA/g tissue respectively). Of particular interest was the observation of significant accumulations of toxic Pseudo-nitzschia sp. diatoms in the internal siphon and atrium spaces of the tunicate. Toxin distribution within major tunicate organs was heterogeneous with 8.7-15.5 microg DA/g in edible tissues, 14.9-17.9 microg DA/g in the fecal material and 13.6-32.7 microg DA/g in the gut content. DA was determined by HPLC-UV and confirmed by diode-array detection and LC-MS/MS analysis. This is the first report of the presence of DA in a tunicate that is regularly consumed by coastal populations. These results confirm the need to include these organisms in sanitation programs for marine toxins.

  4. Numerical Investigation on Windback Seals Used in Aero Engines

    Directory of Open Access Journals (Sweden)

    Michael Flouros

    2018-01-01

    Full Text Available Seals are considered one of the most important flow elements in turbomachinery applications. The most traditional and widely known seal is the labyrinth seal but in recent years other types like the brush or carbon seals were introduced since they considerably reduce the sealing air consumption. When seals are used for sealing of aero engine bearing chambers they are subjected to high “bombardment” through oil particles which are present in the bearing chamber. These particles mainly result from the bearings as a consequence of the high rotational speeds. Particularly when carbon or brush seals are used, problems with carbon formation (coking may arise when oil gets trapped in the very tight gap of these seals. In order to prevent oil migration into the turbomachinery, particularly when the pressure difference over a seal is small or even negligible, significant improvement can be achieved through the introduction of so called windback seals. This seal has a row of static helical teeth (thread and below this thread a scalloped or smooth shaft section is rotating. Depending on the application, a windback seal can be used alone or as a combination with another seal (carbon, brush or labyrinth seal. A CFD analysis carried out with ANSYS CFX version 11 is presented in this paper with the aim to investigate this seal type. The simulations were performed by assuming a two-phase flow of air and oil in the bearing compartment. Design parameters like seal clearance, thread size, scallop width, were investigated at different operating conditions.

  5. Genome-wide analysis of alternative splicing in Chlamydomonas reinhardtii

    Directory of Open Access Journals (Sweden)

    Thomas Julie

    2010-02-01

    Full Text Available Abstract Background Genome-wide computational analysis of alternative splicing (AS in several flowering plants has revealed that pre-mRNAs from about 30% of genes undergo AS. Chlamydomonas, a simple unicellular green alga, is part of the lineage that includes land plants. However, it diverged from land plants about one billion years ago. Hence, it serves as a good model system to study alternative splicing in early photosynthetic eukaryotes, to obtain insights into the evolution of this process in plants, and to compare splicing in simple unicellular photosynthetic and non-photosynthetic eukaryotes. We performed a global analysis of alternative splicing in Chlamydomonas reinhardtii using its recently completed genome sequence and all available ESTs and cDNAs. Results Our analysis of AS using BLAT and a modified version of the Sircah tool revealed AS of 498 transcriptional units with 611 events, representing about 3% of the total number of genes. As in land plants, intron retention is the most prevalent form of AS. Retained introns and skipped exons tend to be shorter than their counterparts in constitutively spliced genes. The splice site signals in all types of AS events are weaker than those in constitutively spliced genes. Furthermore, in alternatively spliced genes, the prevalent splice form has a stronger splice site signal than the non-prevalent form. Analysis of constitutively spliced introns revealed an over-abundance of motifs with simple repetitive elements in comparison to introns involved in intron retention. In almost all cases, AS results in a truncated ORF, leading to a coding sequence that is around 50% shorter than the prevalent splice form. Using RT-PCR we verified AS of two genes and show that they produce more isoforms than indicated by EST data. All cDNA/EST alignments and splice graphs are provided in a website at http://combi.cs.colostate.edu/as/chlamy. Conclusions The extent of AS in Chlamydomonas that we observed is much

  6. CARACTERIZACIÓN DE LA PESCA DEL TIBURÓN MARTILLO SPHYRNA LEWINI , EN LA PARTE EXTERNA DEL GOLFO DE NICOYA, COSTA RICA

    Directory of Open Access Journals (Sweden)

    Ilena Zanella

    2011-07-01

    Full Text Available En el ámbito nivel mundial, el tiburón martillo (Sphyrna lewini es una de las especies más afectadas por la sobrepesca y el aleteo. Recientemente se incorporó a la Lista Roja de la UICN como especie en peligro de extinción. El presente estudio pretendió caracterizar la pesca y la distribución de S. lewini en la parte externa del Golfo de Nicoya. Para lograr este propósito, se realizaron muestreos entre marzo del 2006 y mayo del 2007 y se analizaron los tiburones martillo capturados por pescadores artesanales afiliados a la Cooperativa artesanales de Pescadores de Tárcoles (CoopeTárcoles R. L., que faenan en la parte externa del Golfo de Nicoya. Para cada tiburón, se determinó la longitud total, la zona de pesca donde se capturó y el arte utilizado. En total se analizaron 273 tiburones. Se identificó un área de crianza primaria en el Peñón y se determinó que existe una relación lineal positiva entre la longitud total y la profundidad de la zona de pesca (R2 = 0.4296; p ‹ 0.0001, y la longitud total y la distancia de la zona de pesca de la desembocadura del río Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001. Los tiburones de menor tamaño (crías se encontraron en la zona del Peñón, donde las aguas son poco profundas, turbias y productivas, ofreciendo a las crías alimento y protección de los depredadores. Por lo cual, se recomienda proteger esta zona, en particular en marzo, abril y mayo, época de nacimiento de las crías. The scalloped hammerhead shark (Sphyrna lewini is one of the shark species most impacted by overfishing, and is currently listed by the IUCN Red List as an Endangered.  This research sought to characterize the distribution of S. lewini in the external area of Gulf of Nicoya, central Pacific coast of Costa Rica, based on observations from a coastal artisanal fishery. From March 2006 to May 2007, we analyzed scalloped hammerhead shark landings by members of the Tarcoles Artisanal Fishermen's Cooperative

  7. Mercury in Commercial Fish: Optimizing Individual Choices to Reduce Risk

    Science.gov (United States)

    Burger, Joanna; Stern, Alan H.; Gochfeld, Michael

    2005-01-01

    Most attention to the risks from fish consumption has focused on recreational anglers and on fish caught by individuals, but the majority of fish that people eat are purchased from commercial sources. We examined mercury levels in three types of fish (tuna, flounder, bluefish) commonly available in New Jersey stores, sampling different regions of the state, in communities with high and low per capita incomes, and in both supermarkets and specialty fish markets. We were interested in species-specific levels of mercury in New Jersey fish and whether these levels were similar to data generated nationally by the Food and Drug Administration (FDA; mainly from 1990 to 1992) on the same types of fish. Such information is critical for providing public health advice. We were also interested in whether mercury levels in three common species of fish differed by region of the state, economic neighborhood, or type of store. We found significant species differences, with tuna having the highest levels and flounder the lowest levels. There were no significant differences in mercury levels as a function of type of store or economic neighborhood. There was only one regional difference: flounder from fish markets along the Jersey shore had higher mercury levels than flounder bought in other markets. We also examined mercury levels in six other commonly available fish and two shellfish from central New Jersey markets. There were significant differences in availability and in mercury levels among fish and shellfish. Both shrimp and scallops had total mercury levels tuna, sea bass, croaker, whiting, scallops, and shrimp, the levels of mercury were higher in New Jersey samples than those reported by the FDA. Consumers selecting fish for ease of availability (present in > 50% of markets) would select flounder, snapper, bluefish, and tuna (tuna had the highest mercury value), and those selecting only for price would select whiting, porgy, croaker, and bluefish (all with average mercury

  8. Transcriptome characterization and high throughput SSRs and SNPs discovery in Cucurbita pepo (Cucurbitaceae).

    Science.gov (United States)

    Blanca, José; Cañizares, Joaquín; Roig, Cristina; Ziarsolo, Pello; Nuez, Fernando; Picó, Belén

    2011-02-10

    Cucurbita pepo belongs to the Cucurbitaceae family. The "Zucchini" types rank among the highest-valued vegetables worldwide, and other C. pepo and related Cucurbita spp., are food staples and rich sources of fat and vitamins. A broad range of genomic tools are today available for other cucurbits that have become models for the study of different metabolic processes. However, these tools are still lacking in the Cucurbita genus, thus limiting gene discovery and the process of breeding. We report the generation of a total of 512,751 C. pepo EST sequences, using 454 GS FLX Titanium technology. ESTs were obtained from normalized cDNA libraries (root, leaves, and flower tissue) prepared using two varieties with contrasting phenotypes for plant, flowering and fruit traits, representing the two C. pepo subspecies: subsp. pepo cv. Zucchini and subsp. ovifera cv Scallop. De novo assembling was performed to generate a collection of 49,610 Cucurbita unigenes (average length of 626 bp) that represent the first transcriptome of the species. Over 60% of the unigenes were functionally annotated and assigned to one or more Gene Ontology terms. The distributions of Cucurbita unigenes followed similar tendencies than that reported for Arabidopsis or melon, suggesting that the dataset may represent the whole Cucurbita transcriptome. About 34% unigenes were detected to have known orthologs of Arabidopsis or melon, including genes potentially involved in disease resistance, flowering and fruit quality. Furthermore, a set of 1,882 unigenes with SSR motifs and 9,043 high confidence SNPs between Zucchini and Scallop were identified, of which 3,538 SNPs met criteria for use with high throughput genotyping platforms, and 144 could be detected as CAPS. A set of markers were validated, being 80% of them polymorphic in a set of variable C. pepo and C. moschata accessions. We present the first broad survey of gene sequences and allelic variation in C. pepo, where limited prior genomic

  9. Transcriptome characterization and high throughput SSRs and SNPs discovery in Cucurbita pepo (Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Nuez Fernando

    2011-02-01

    Full Text Available Abstract Background Cucurbita pepo belongs to the Cucurbitaceae family. The "Zucchini" types rank among the highest-valued vegetables worldwide, and other C. pepo and related Cucurbita spp., are food staples and rich sources of fat and vitamins. A broad range of genomic tools are today available for other cucurbits that have become models for the study of different metabolic processes. However, these tools are still lacking in the Cucurbita genus, thus limiting gene discovery and the process of breeding. Results We report the generation of a total of 512,751 C. pepo EST sequences, using 454 GS FLX Titanium technology. ESTs were obtained from normalized cDNA libraries (root, leaves, and flower tissue prepared using two varieties with contrasting phenotypes for plant, flowering and fruit traits, representing the two C. pepo subspecies: subsp. pepo cv. Zucchini and subsp. ovifera cv Scallop. De novo assembling was performed to generate a collection of 49,610 Cucurbita unigenes (average length of 626 bp that represent the first transcriptome of the species. Over 60% of the unigenes were functionally annotated and assigned to one or more Gene Ontology terms. The distributions of Cucurbita unigenes followed similar tendencies than that reported for Arabidopsis or melon, suggesting that the dataset may represent the whole Cucurbita transcriptome. About 34% unigenes were detected to have known orthologs of Arabidopsis or melon, including genes potentially involved in disease resistance, flowering and fruit quality. Furthermore, a set of 1,882 unigenes with SSR motifs and 9,043 high confidence SNPs between Zucchini and Scallop were identified, of which 3,538 SNPs met criteria for use with high throughput genotyping platforms, and 144 could be detected as CAPS. A set of markers were validated, being 80% of them polymorphic in a set of variable C. pepo and C. moschata accessions. Conclusion We present the first broad survey of gene sequences and allelic

  10. High-throughput SNP genotyping in Cucurbita pepo for map construction and quantitative trait loci mapping

    Directory of Open Access Journals (Sweden)

    Esteras Cristina

    2012-02-01

    Full Text Available Abstract Background Cucurbita pepo is a member of the Cucurbitaceae family, the second- most important horticultural family in terms of economic importance after Solanaceae. The "summer squash" types, including Zucchini and Scallop, rank among the highest-valued vegetables worldwide. There are few genomic tools available for this species. The first Cucurbita transcriptome, along with a large collection of Single Nucleotide Polymorphisms (SNP, was recently generated using massive sequencing. A set of 384 SNP was selected to generate an Illumina GoldenGate assay in order to construct the first SNP-based genetic map of Cucurbita and map quantitative trait loci (QTL. Results We herein present the construction of the first SNP-based genetic map of Cucurbita pepo using a population derived from the cross of two varieties with contrasting phenotypes, representing the main cultivar groups of the species' two subspecies: Zucchini (subsp. pepo × Scallop (subsp. ovifera. The mapping population was genotyped with 384 SNP, a set of selected EST-SNP identified in silico after massive sequencing of the transcriptomes of both parents, using the Illumina GoldenGate platform. The global success rate of the assay was higher than 85%. In total, 304 SNP were mapped, along with 11 SSR from a previous map, giving a map density of 5.56 cM/marker. This map was used to infer syntenic relationships between C. pepo and cucumber and to successfully map QTL that control plant, flowering and fruit traits that are of benefit to squash breeding. The QTL effects were validated in backcross populations. Conclusion Our results show that massive sequencing in different genotypes is an excellent tool for SNP discovery, and that the Illumina GoldenGate platform can be successfully applied to constructing genetic maps and performing QTL analysis in Cucurbita. This is the first SNP-based genetic map in the Cucurbita genus and is an invaluable new tool for biological research

  11. High-throughput SNP genotyping in Cucurbita pepo for map construction and quantitative trait loci mapping.

    Science.gov (United States)

    Esteras, Cristina; Gómez, Pedro; Monforte, Antonio J; Blanca, José; Vicente-Dólera, Nelly; Roig, Cristina; Nuez, Fernando; Picó, Belén

    2012-02-22

    Cucurbita pepo is a member of the Cucurbitaceae family, the second- most important horticultural family in terms of economic importance after Solanaceae. The "summer squash" types, including Zucchini and Scallop, rank among the highest-valued vegetables worldwide. There are few genomic tools available for this species.The first Cucurbita transcriptome, along with a large collection of Single Nucleotide Polymorphisms (SNP), was recently generated using massive sequencing. A set of 384 SNP was selected to generate an Illumina GoldenGate assay in order to construct the first SNP-based genetic map of Cucurbita and map quantitative trait loci (QTL). We herein present the construction of the first SNP-based genetic map of Cucurbita pepo using a population derived from the cross of two varieties with contrasting phenotypes, representing the main cultivar groups of the species' two subspecies: Zucchini (subsp. pepo) × Scallop (subsp. ovifera). The mapping population was genotyped with 384 SNP, a set of selected EST-SNP identified in silico after massive sequencing of the transcriptomes of both parents, using the Illumina GoldenGate platform. The global success rate of the assay was higher than 85%. In total, 304 SNP were mapped, along with 11 SSR from a previous map, giving a map density of 5.56 cM/marker. This map was used to infer syntenic relationships between C. pepo and cucumber and to successfully map QTL that control plant, flowering and fruit traits that are of benefit to squash breeding. The QTL effects were validated in backcross populations. Our results show that massive sequencing in different genotypes is an excellent tool for SNP discovery, and that the Illumina GoldenGate platform can be successfully applied to constructing genetic maps and performing QTL analysis in Cucurbita. This is the first SNP-based genetic map in the Cucurbita genus and is an invaluable new tool for biological research, especially considering that most of these markers are located in

  12. The compatibility of p-branch "off-the-shelf" fenestrated endovascular graft in Asian patients with juxtarenal aortic aneurysm.

    Science.gov (United States)

    Ou, Jiale; Cheng, Stephen W K; Chan, Yiu Che

    2015-06-01

    The Zenith pivot branch (p-branch) fenestrated endovascular graft (Cook Medical, Bloomington, Ind) is a new "off-the-shelf" device to treat patients with juxtarenal aortic aneurysms (JRAs). Two options are currently available, which appear to suit >70% of white patients. This study investigates the anatomic applicability of the p-branch fenestrated graft in a cohort of Asian patients with JRA. Computed tomography images of 51 consecutive Asian patients with JRA (43 men; mean age, 76.8 years) were analyzed on an Aquarius workstation (TeraRecon, San Mateo, Calif) and matched to two current configurations of the p-branch (options A and B: single superior mesenteric artery [SMA] and two renal fenestrations, and a celiac axis scallop). With use of the SMA as reference, the anatomic positions of both renal arteries and the celiac axis were figured together with their diameters on a template generated on MATLAB (MathWorks, Natick, Mass), and then they were matched with two graft configurations. The renal artery origins were assessed for three classes of "closeness of fit" based on diameter: perfect match, marginal match, and mismatch, respectively, defined as the renal artery origins being located entirely inside, partially inside, and completely outside their corresponding fenestrations. The suitability of the p-branch graft design to the aneurysms was then evaluated. A total of 31 JRA patients (60.8%) were regarded as suitable candidates for one or both p-branch stent grafts (20 with option A, 22 with option B, and 11 with both options). In 35 patients (68.6%), both renal arteries could be aligned with the fenestrations. Among them, 16 patients (31.4%) were perfectly matched, whereas 19 patients (37.2%) were only marginally suitable. The major reason for exclusion was the misalignment of the renal fenestrations. In 16 patients with unsuitable renal fenestrations, 8 were attributed to the right renal origins being located too distally compared with their corresponding

  13. Liquid Chromatography with a Fluorimetric Detection Method for Analysis of Paralytic Shellfish Toxins and Tetrodotoxin Based on a Porous Graphitic Carbon Column

    Directory of Open Access Journals (Sweden)

    Veronica Rey

    2016-06-01

    Full Text Available Paralytic shellfish toxins (PST traditionally have been analyzed by liquid chromatography with either pre- or post-column derivatization and always with a silica-based stationary phase. This technique resulted in different methods that need more than one run to analyze the toxins. Furthermore, tetrodotoxin (TTX was recently found in bivalves of northward locations in Europe due to climate change, so it is important to analyze it along with PST because their signs of toxicity are similar in the bioassay. The methods described here detail a new approach to eliminate different runs, by using a new porous graphitic carbon stationary phase. Firstly we describe the separation of 13 PST that belong to different groups, taking into account the side-chains of substituents, in one single run of less than 30 min with good reproducibility. The method was assayed in four shellfish matrices: mussel (Mytillus galloprovincialis, clam (Pecten maximus, scallop (Ruditapes decussatus and oyster (Ostrea edulis. The results for all of the parameters studied are provided, and the detection limits for the majority of toxins were improved with regard to previous liquid chromatography methods: the lowest values were those for decarbamoyl-gonyautoxin 2 (dcGTX2 and gonyautoxin 2 (GTX2 in mussel (0.0001 mg saxitoxin (STX·diHCl kg−1 for each toxin, decarbamoyl-saxitoxin (dcSTX in clam (0.0003 mg STX·diHCl kg−1, N-sulfocarbamoyl-gonyautoxins 2 and 3 (C1 and C2 in scallop (0.0001 mg STX·diHCl kg−1 for each toxin and dcSTX (0.0003 mg STX·diHCl kg−1 in oyster; gonyautoxin 2 (GTX2 showed the highest limit of detection in oyster (0.0366 mg STX·diHCl kg−1. Secondly, we propose a modification of the method for the simultaneous analysis of PST and TTX, with some minor changes in the solvent gradient, although the detection limit for TTX does not allow its use nowadays for regulatory purposes.

  14. Efficient thermal noise removal of Sentinel-1 image and its impacts on sea ice applications

    Science.gov (United States)

    Park, Jeong-Won; Korosov, Anton; Babiker, Mohamed

    2017-04-01

    Wide swath SAR observation from several spaceborne SAR missions played an important role in studying sea ice in the polar region. Sentinel 1A and 1B are producing dual-polarization observation data with the highest temporal resolution ever. For a proper use of dense time-series, radiometric properties must be qualified. Thermal noise is often neglected in many sea ice applications, but is impacting seriously the utility of dual-polarization SAR data. Sentinel-1 TOPSAR image intensity is disturbed by additive thermal noise particularly in cross-polarization channel. Although ESA provides calibrated noise vectors for noise power subtraction, residual noise contribution is significant considering relatively narrow backscattering distribution of cross-polarization channel. In this study, we investigate the noise characteristics and propose an efficient method for noise reduction based on three types of correction: azimuth de-scalloping, noise scaling, and inter-swath power balancing. The core idea is to find optimum correction coefficients resulting in the most noise-uncorrelated gentle backscatter profile over homogeneous region and to combine them with scalloping gain for reconstruction of complete two-dimensional noise field. Denoising is accomplished by subtracting the reconstructed noise field from the original image. The resulting correction coefficients determined by extensive experiments showed different noise characteristics for different Instrument Processing Facility (IPF) versions of Level 1 product generation. Even after thermal noise subtraction, the image still suffers from residual noise, which distorts local statistics. Since this residual noise depends on local signal-to-noise ratio, it can be compensated by variance normalization with coefficients determined from an empirical model. Denoising improved not only visual interpretability but also performances in SAR intensity-based sea ice applications. Results from two applications showed the

  15. Dynamic Angular Control Of Thermal Therapy With Stationary Multi-Sectored Tubular Ultrasound Applicators Under MR Temperature Monitoring

    Science.gov (United States)

    Kinsey, Adam M.; Diederich, Chris J.; Nau, William H.; Ross, Anthony B.; Butts Pauly, Kim; Rieke, Viola; Sommer, Graham

    2006-05-01

    Multi-sectored ultrasound heating applicators with dynamic angular and longitudinal control of heating profiles are being investigated for the thermal treatment of tumors in sites such as prostate, uterus, and brain. Multi-sectored tubular ultrasound transducers with independent sector power control were incorporated into interstitial and transurethral applicators and provided dynamic angular control of a heating pattern without requiring device manipulation during treatment. Acoustic beam measurements of each applicator type demonstrated a 35-40° acoustic dead zone between each independent sector, with negligible mechanical or electrical coupling. Despite the acoustic dead zone between sectors, simulations and experiments under MR temperature (MRT) monitoring showed that the variance from the maximum lesion radius (scalloping) with all elements activated on a transducer was minimal and did not affect conformal heating of a target area. A biothermal model with a multi-point controller was used to adjust the applied power and treatment time of individual transducer segments as the tissue temperature changed in simulations of thermal lesions with both interstitial and transurethral applicators. Transurethral ultrasound applicators for benign prostatic hyperplasia (BPH) treatment with either three or four sectors conformed a thermal dose to a simulated target area in the angular and radial dimensions. The simulated treatment was controlled to a maximum temperature of 85°C, and had a maximum duration of 5 min when power was turned off as the 52°C temperature contour reach a predetermined control point for each sector in the tissue. Experiments conducted with multi-sectored applicators under MRT monitoring showed thermal ablation and hyperthermia treatments had little or no border `scalloping', conformed to a pretreatment target area, and correlated very well with the simulated thermal lesions. The radial penetration of the heat treatments in tissue with interstitial

  16. Spectrum of biliary abnormalities in portal cavernoma cholangiopathy (PCC) secondary to idiopathic extrahepatic portal vein obstruction (EHPVO)-a prospective magnetic resonance cholangiopancreaticography (MRCP) based study.

    Science.gov (United States)

    Jabeen, Shumyla; Robbani, Irfan; Choh, Naseer A; Ashraf, Obaid; Shaheen, Feroze; Gojwari, Tariq; Gul, Sabeeha

    2016-12-01

    To characterize biliary abnormalities seen in portal cavernoma cholangiopathy (PCC) on MR cholangiopancreaticography (MRCP) and elucidate certain salient features of the disease by collaborating our findings with those of previous studies. We prospectively enrolled 52 patients with portal cavernoma secondary to idiopathic extrahepatic portal vein obstruction, who underwent a standard MRCP protocol. Images were analyzed for abnormalities involving the entire biliary tree. Terms used were those proposed by the Indian National Association for Study of the Liver. Angulation of the common bile duct (CBD) was measured in all patients with cholangiopathy. Cholangiopathy was seen in 80.7% of patients on MRCP. Extrahepatic ducts were involved in 95% of patients either alone (26%) or in combination with the intrahepatic ducts (69%). Isolated involvement of the intrahepatic ducts was seen in 4.8% of patients. Abnormalities of the extrahepatic ducts included angulation (90%), scalloping (76.2%), extrinsic impression/indentation (45.2%), stricture (14.3%) and smooth dilatation (4.8%). The mean CBD angle was 113.2 ± 19.8°. Abnormalities of the intrahepatic ducts included smooth dilatation (40%), irregularity (28%) and narrowing (9%). Cholelithiasis, choledocholithiasis and hepatolithiasis were seen in 28.6% (12) patients, 14.3% (6) patients and 11.9% (5) patients, respectively. There was a significant association between choledocholithiasis and CBD stricture, with no significant association between choledocholithiasis and cholelithiasis. A significant association was also seen between hepatolithiasis and choledocholithiasis. The spectrum of biliary abnormalities in PCC has been explored and some salient features of the disease have been elucidated, which allow a confident diagnosis of this entity. Advances in knowledge: PCC preferentially involves the extrahepatic biliary tree. Changes in the intrahepatic ducts generally occur as sequelae of involvement of the extrahepatic

  17. Cartilage tumors. Pathology and radiomorphology; Chondrogene Knochentumoren. Pathologie und Radiomorphologie

    Energy Technology Data Exchange (ETDEWEB)

    Uhl, M. [RKK-Klinikum Freiburg, Klinik fuer Diagnostische und Interventionelle Radiologie, Kinderradiologie und Neuroradiologie SJK, Freiburg (Germany); Herget, G. [Universitaetsklinik Freiburg, Department Orthopaedie und Traumatologie, Freiburg (Germany); Kurz, P. [Universitaetsklinik Freiburg, Pathologisches Institut, Freiburg (Germany)

    2016-06-15

    Primary cartilage-forming tumors of the bone are frequent entities in the daily work of skeletal radiologists. This article describes the correlation of pathology and radiology in cartilage-forming skeletal tumors, in particular, enchondroma, osteochondroma, periosteal chondromas, chondroblastoma and various forms of chondrosarcoma. After reading, the radiologist should be able to deduce the different patterns of cartilage tumors on radiographs, CT, and MRI from the pathological aspects. Differentiation of enchondroma and chondrosarcoma is a frequent diagnostic challenge. Some imaging parameters, e. g., deep cortical scalloping (more than two thirds of the cortical thickness), cortical destruction, or a soft-tissue mass, are features of a sarcoma. Osteochondromas are bony protrusions with a continuous extension of bone marrow from the parent bone, the host cortical bone runs continuously from the osseous surface of the tumor into the shaft of the osteochondroma and the osteochondroma has a cartilage cap. Chondromyxoid fibromas are well-defined lytic and eccentric lesions of the metaphysis of the long bones, with nonspecific MRI findings. Chondroblastomas have a strong predilection for the epiphysis of long tubular bones and develop an intense perifocal bone marrow edema. Dedifferentiated chondrosarcomas are bimorphic lesions with a low-grade chondrogenic component and a high-grade noncartilaginous component. Most chondrogenic tumors have a predilection with regard to site and age at manifestation. (orig.) [German] Primaere knorpelbildende Tumoren sind haeufige Entitaeten in der taeglichen Arbeit des Radiologen. Der Beitrag beschreibt die Korrelation von Pathologie und Radiologie knorpelbildender Skeletttumoren, insbesondere von Enchondrom, Osteochondrom, periostalem Chondrom, Chondroblastom, und verschiedenen Varianten des Chondrosarkoms. Nach Lesen des Beitrags kann der Radiologe die verschiedenen typischen Muster knorpelbildender Tumoren im Roentgenbild

  18. Assessment of midpalatal suture ossification using cone-beam computed tomography.

    Science.gov (United States)

    Haghanifar, Sina; Mahmoudi, Sadaf; Foroughi, Ramin; Mir, Arash Poorsattar Bejeh; Mesgarani, Abas; Bijani, Ali

    2017-03-01

    The degree of ossification of the midpalatal suture is an important factor in the selection of treatment procedure, especially in young individuals. Considering the discrepancies in the results of studies on the exact time of the closure of this suture, the present study was undertaken to evaluate ossification and morphology of the suture with the use of CBCT. In the present cross-sectional study, the CBCT images of the maxilla in 144 Iranian subjects (72 males, 72 females) with an age range of 10 to 70 years, referring to a private radiology center in Sari, Iran, were evaluated. The CBCT images were evaluated in the axial cross-sectional slice at 1 mm intervals to determine morphology and the maturation stage of the suture and its degree of ossification. The six developmental stages that were observed were as follows: stage A, a direct line without disturbances; stage B, a scalloped appearance in the suture; stage C, two parallel lines with a scalloped appearance that were connected at some points; stage CD, the anterior portion was similar to stage C, and the posterior region was similar to stage D; stage D, ossification only in the palatine bone; stage E, complete ossification of the suture. The degree of ossification of the suture was calculated with the use of the ratio of the length of the ossified segment to the entire length of the suture. Data were analyzed with Spearman's correlation test, Chi-squared test, t-test, ANOVA, Mann-Whitney U, and Kruskal-Wallis test. Intra-observer agreement was calculated with the use of weighted kappa coefficient. Data were analyzed with SPSS 17. There was a strong correlation between the age groups and the developmental stages of the midpalatal suture in both genders (r=0.681, ptwo genders (p=0.193). Although the rate of suture closure increased with aging, age was not a reliable factor alone to determine the developmental stage of the suture. Use of CBCT is necessary in all the patients to determine the degree of

  19. Transformation of paralytic shellfish poisoning toxins in UK surf clams (Spisula solida) for targeted production of reference materials.

    Science.gov (United States)

    Turner, Andrew D; Lewis, Adam M; O'Neil, Alison; Hatfield, Robert G

    2013-04-01

    The periodic occurrence of Paralytic Shellfish Poisoning (PSP) toxins in UK surf clams and the recent move away from biological assays for PSP testing resulted in the need to determine method performance characteristics for the replacement analytical method in this species. With the requirement for laboratory reference materials to aid this validation together with known issues relating to toxin transformation in live clams and homogenised tissue, there was the need to assess the toxin transformation characteristics of PSP toxins in surf clam tissue. Initial work examined the rates of toxin transformation in UK surf clam tissue incubated with toxin standards, showing rapid transformation of N-sulfocarbamoyl toxins with slower transformation of carbamate toxins. Full transformational pathways were determined using a combination of three different analytical methods and confirmed the major expected transformations involving decarbamoylation, with some evidence for additional reaction pathways. Results obtained from the analysis of surf clam and oyster tissues incubated with varying concentrations of toxic Alexandrium algae highlighted expected transformation reactions, although significant differences were observed in the extent of the transformations amongst the range of toxins studied, with less efficient transformation of N-hydroxylated toxins as compared with other carbamate and N-sulfocarbamoyl toxins. Analysis of PSP-toxic incurred oyster, scallop and mussel tissues incubated with variable proportions of surf clam tissue showed large differences in the extent of the transformations. Total conversion of N-sulfocarbamoyl toxins was confirmed at low relative proportions of surf clam tissue in all three species, whereas transformation of carbamate toxins was found to occur only in the presence of higher proportions of surf clam tissue in oysters and mussels in comparison with scallops. Results enabled the production of three laboratory reference materials prepared

  20. Odontoblast dysfunction in osteogenesis imperfecta: an LM, SEM, and ultrastructural study.

    Science.gov (United States)

    Hall, R K; Manière, M C; Palamara, J; Hemmerlé, J

    2002-01-01

    The inherited dentin defect dentinogenesis imperfecta (DI), while clinically obvious in osteogenesis imperfecta (OI) Types IB and IC, II, III, and IVB, is now thought to be present in all children with OI, in a continuum from minimal to severe dentin pathology. This collaborative study further clarifies the structural and ultrastructural dentin changes in the teeth of OI children with clinically obvious DI, and attempts to explain these in terms of odontoblast dysfunction. Collaborative studies were carried out in Melbourne, Australia, and Strasbourg, France, using light and polarized-light microscopy, scanning and transmission electron microscopy (SEM, TEM), selected-area diffraction (SAD), and x-ray spectroscopy (EDX). These showed structurally normal enamel (but containing long and broad lamellae) and a normally scalloped dentino-enamel junction (DEJ), but severe pathologic changes in the dentin. An initial narrow band of normal-appearing dentin tubules (including the mantle layer) ceased abruptly and was replaced by a wavelike laminar zone parallel to the DEJ with occluded tubules. Multiple parallel channels of 5-10 microns diameter were present at right angles to the DEJ indenting this zone, some terminating in retro-curved "processes." The abnormal dentin containing these channels almost completely occluded the pulp chamber. The structural and ultrastructural changes seen can be explained on the basis of the collagen defect in OI resulting in odontoblast dysfunction, which produces a distinct phenotype and one that is different from that in bone.