WorldWideScience

Sample records for bivalve nacre manifest

  1. Dynamics of sheet nacre formation in bivalves

    OpenAIRE

    Rousseau, Marthe; Meibom, Anders; Gèze, Marc; Bourrat, Xavier; Angellier, Martine; Lopez, Evelyne

    2009-01-01

    Formation of nacre (mother-of-pearl) is a biomineralization process of fundamental scientific as well as industrial importance. However, the dynamics of the formation process is still not understood. Here, we use scanning electron microscopy and high spatial resolution ion microprobe depth-profiling to image the full three-dimensional distribution of organic materials around individual tablets in the top-most layer of forming nacre in bivalves. Nacre formation proceeds by lateral, symmetric g...

  2. Mineral bridges in nacre revisited

    CERN Document Server

    Checa, Antonio G; Willinger, Marc-Georg

    2012-01-01

    We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200 nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (> 100 nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (< 60 nm), earlier reported to be mineral bridges, found to be such.

  3. Nacre and false nacre (foliated aragonite) in extant monoplacophorans (=Tryblidiida: Mollusca)

    Science.gov (United States)

    Checa, Antonio G.; Ramírez-Rico, Joaquín; González-Segura, Alicia; Sánchez-Navas, Antonio

    2009-01-01

    Extant monoplacophorans (Tryblidiida, Mollusca) have traditionally been reported as having an internal nacreous layer, thus representing the ancestral molluscan condition. The examination of this layer in three species of Neopilinidae ( Rokopella euglypta, Veleropilina zografi, and Micropilina arntzi) reveals that only V. zografi secretes an internal layer of true nacre, which occupies only part of the internal shell surface. The rest of the internal surface of V. zografi and the whole internal surfaces of the other two species examined are covered by a material consisting of lath-like, instead of brick-like, crystals, which are arranged into lamellae. In all cases examined, the crystallographic c-axis in this lamellar material is perpendicular to the surface of laths and the a-axis is parallel to their long dimension. The differences between taxa relate to the frequency of twins, which is much higher in Micropilina. In general, the material is well ordered, particularly towards the margin, where lamellae pile up at a small step size, which is most likely due to processes of crystal competition. Given its morphological resemblance to the foliated calcite of bivalves, we propose the name foliated aragonite for this previously undescribed biomaterial secreted by monoplacophorans. We conclude that the foliated aragonite probably lacks preformed interlamellar membranes and is therefore not a variant of nacre. A review of the existing literature reveals that previous reports of nacre in the group were instead of the aragonitic foliated layer and that our report of nacre in V. zografi is the first undisputed evidence of nacre in monoplacophorans. From the evolutionary viewpoint, the foliated aragonite could easily have been derived from nacre. Assuming that nacre represents the ancestral condition, as in other molluscan classes, it has been replaced by foliated aragonite along the tryblidiidan lineage, although the fossil record does not presently provide evidence as to

  4. Polarimetry of nacre in iridescent shells

    Science.gov (United States)

    Metzler, R. A.; Burgess, C.; Regan, B.; Spano, S.; Galvez, E. J.

    2014-09-01

    We investigate the light transmitted or reflected from nacre (mother of pearl) taken from the iridescent shell of the bivalve Pinctad a fucata. These nacre surfaces have a rich structure, composed of aragonite crystals arranged as tablets or bricks, 5 μm wide and 400-500 nm thick, surrounded by 30nm thick organic mortar. The light reflected from these shell surfaces, or transmitted through thin polished layers, is rich in its polarization content, exhibiting a space dependent variation in the state of polarization with a high density of polarization singularities. Our goal is to use the polarization information to infer the structure of the biominerals and the role of the organic layer in determining the orientation of the crystals. In the experiments we send the light from a laser with a uniform state of polarization onto the shell, and analyze the light that is either transmitted or reflected, depending on the type of experiment, imaging it after its passage through polarization filters. We use the images from distinct filters to obtain the Stokes parameters, and hence the state of polarization, of each image point. We also construct the Mueller matrix for each imaged point, via 36 measurements. We do this for distinct physical and chemical treatments of the shell sample. Preliminary data shows that the organic layer may be responsible for organizing a multi-crystalline arrangement of aragonite tablets.

  5. Ballistic Impact Behavior of Nacre-Like Laminated Composites Consisting of B4C Tablets and Polyurea Matrix

    Science.gov (United States)

    Grujicic, M.; Snipes, J. S.; Ramaswami, S.

    2016-03-01

    A nacre-like composite armor consisting of B4C tablets and polyurea matrix is modeled, and its ballistic impact behavior and penetration resistance (under a normal and a 15°-oblique impact by a solid right circular cylindrical projectile) were analyzed using a series of transient, nonlinear dynamic, finite-element analyses. Nacre is a biological material constituting the innermost layer of the shells of gastropods and bivalves. It consists of polygonal tablets of aragonite, tessellated to form individual layers and having the adjacent layers as well as the tablets within a layer bonded by a biopolymer. Due to its highly complex hierarchical microstructure, nacre possesses an outstanding combination of mechanical properties, the properties which are far superior to the ones that are predicted using the homogenization techniques such as the rule of mixtures. The results of the transient nonlinear dynamic analysis pertaining to the ballistic impact response and the penetration resistance of the modeled nacre-like armor are compared with their counterparts for the B4C single-block armor having an identical areal density. Furthermore, the effect of various nacre microstructural features (e.g., surface profiling, micron-scale asperities, mineral bridges between the overlapping tablets lying in adjacent layers) on the ballistic penetration resistance of the nacre-like composite armor is investigated in order to identify an optimal nacre-like composite-armor architecture having the largest penetration resistance. The results obtained clearly show that a nacre-like armor possesses a superior penetration resistance relative to its monolithic counterpart, and that the nacre microstructural features considered play a critical role in the armor penetration resistance.

  6. Nacre-like ceramic/polymer laminated composite for use in body-armor applications

    Directory of Open Access Journals (Sweden)

    Mica Grujicic

    2016-01-01

    Full Text Available Nacre is a biological material constituting the innermost layer of the shells of gastropods and bivalves. It consists of polygonal tablets of aragonite, tessellated to form individual layers and having the adjacent layers as well as the tablets within a layer bonded by a biopolymer. Due to its highly complex hierarchical microstructure, nacre possesses an outstanding combination of mechanical properties, the properties which are far superior to the ones that are predicted using the techniques such as the rule of mixture. In the present work, an attempt is made to model a nacre-like composite armor consisting of boron carbide (B4C tablets and polyurea tablet/tablet interfaces. The armor is next investigated with respect to impact by a solid right-circular-cylindrical rigid projectile, using a transient non-linear dynamics finite element analysis. The ballistic-impact response and the penetration resistance of the armor is then compared with that of the B4C monolithic armor having an identical areal density. Furthermore, the effect of various nacre microstructural features (e.g. surface profiling, micron-scale asperities, mineral bridges between the overlapping tablets lying in adjacent layers, and B4C nano-crystallinity on the ballistic-penetration resistance of the composite-armor is investigated in order to identify an optimal nacre-like composite-armor architecture having the largest penetration resistance. The results obtained clearly show that a nacre-like armor possesses a superior penetration resistance relative to its monolithic counterpart, and that the nacre microstructural features considered play a critical role in the armor penetration resistance.

  7. Sheet nacre growth mechanism: a Voronoi model.

    OpenAIRE

    Rousseau, Marthe; Lopez, Evelyne; Couté, Alain; Mascarel, Gérard; David C. Smith; Naslain, Roger; Bourrat, Xavier

    2005-01-01

    Shell nacre (mother of pearl) of Pinctada margaritifera was analyzed by scanning electron microscopy. The originality of this work concerns the sampling performed to observe incipient nacre on the mantle side. The whole animal is embedded in methyl methacrylate followed by separation of the shell from the hardened mantle. It is revealed this way how each future nacre layer pre-exists as a film or compartment. Experimental observations also show for the first time, the progressive lateral crys...

  8. Multiscale structure of sheet nacre.

    OpenAIRE

    Rousseau, Marthe; Lopez, Evelyne; Stempflé, Philippe; Brendlé, Marcel; Franke, Loïc; Guette, Alain; Naslain, Roger; Bourrat, Xavier

    2005-01-01

    This work was conducted on Pinctada maxima nacre (mother of pearl) in order to understand its multiscale ordering and the role of the organic matrix in its structure. Intermittent-contact atomic force microscopy with phase detection imaging reveals a nanostructure within the tablet. A continuous organic framework divides each tablet into nanograins. Their shape is supposed to be flat with a mean extension of 45 nm. TEM performed in the darkfield mode evidences that at least part of the intrac...

  9. MINERAL BRIDGES OF NACRE AND ITS EFFECTS

    Institute of Scientific and Technical Information of China (English)

    宋凡; 白以龙

    2001-01-01

    Nacre, or mother-of-pearl, is a kind of composites of aragonite platelets sandwiched between organic materials. Its excellent mechanical properties are thought to stem from the microarchitecture that is traditionally described as a "brick and mortar" arrangement. In this paper, a new microstructure, referred to as mineral bridge in the biomineralization, is directly observed in the organic matrix layers (mortar) of nacre. This is an indication that the organic matrix layer of nacre should be treated as a three-dimensional interface and the microarchitecture of nacre ought to be considered as a "brick-bridge-mortar" structure rather than the traditional one. Experiments and analyses show that the mineral bridges not only improve the mechanical properties of the organic matrix layers but also play an important role in the pattern of the crack extension in nacre.

  10. The in vitro osteoclastic degradation of nacre.

    Science.gov (United States)

    Duplat, D; Chabadel, A; Gallet, M; Berland, S; Bédouet, L; Rousseau, M; Kamel, S; Milet, C; Jurdic, P; Brazier, M; Lopez, E

    2007-04-01

    Osteoclast activity was studied on nacre, the mother of pearl (MOP) in order to assess the plasticity of bone resorbing cells and their capacity to adapt to a biomineralized material with a different organic and mineral composition from that of its natural substrate, bone. Pure MOP, a natural biomineralized CaCO(3) material, was obtained from Pinctada oyster shell. When implanted in the living system, nacre has proven to be a sustainable bone grafting material although a limited surface degradation process. Osteoclast stem cells and mature osteoclasts were cultured on MOP substrate and osteoclast precursor cells were shown to differentiate into osteoclasts capable of resorbing nacre substrate. However, analysis of the organization of the cytoskeleton showed that both a sealing zone and a podosome structure were observed on the nacre substrate. Moreover, MOP resorption efficiency was consistently found to be lower than that of bone and appeared to be a limited process. PMID:17258312

  11. Hybridized/Coupled Multiple Resonances in Nacre

    OpenAIRE

    Choi, Seung Ho; Kim, Young L.

    2014-01-01

    We report that nacre (also known as mother-of-pearl), a wondrous nanocomposite found in nature, is a rich photonic nanomaterial allowing the experimental realization of collective excitation and light amplification via coupled states. Localized modes in three-dimensional complex media are typically isolated in frequency and space. However, multiple local resonances can be hybridized in multilayered nanostructures of nacre so that the effective cavity size for efficient disordered resonators i...

  12. Gradual Ordering in Red Abalone Nacre

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, P. U. P. A.; Metzler, Rebecca A.; Zhou, Dong; Scholl, Andreas; Doran, Andrew; Young, Anthony; Kunz, Martin; Tamura, Nobumichi; Coppersmith, Susan N.

    2008-09-03

    Red abalone (Haliotis rufescens) nacre is a layered composite biomineral that contains crystalline aragonite tablets confined by organic layers. Nacre is intensely studied because its biologically controlled microarchitecture gives rise to remarkable strength and toughness, but the mechanisms leading to its formation are not well understood. Here we present synchrotron spectromicroscopy experiments revealing that stacks of aragonite tablet crystals in nacre are misoriented with respect to each other. Quantitative measurements of crystal orientation, tablet size, and tablet stacking direction show that orientational ordering occurs not abruptly but gradually over a distance of 50 {micro}m. Several lines of evidence indicate that different crystal orientations imply different tablet growth rates during nacre formation. A theoretical model based on kinetic and gradual selection of the fastest growth rates produces results in qualitative and quantitative agreement with the experimental data and therefore demonstrates that ordering in nacre is a result of crystal growth kinetics and competition either in addition or to the exclusion of templation by acidic proteins as previously assumed. As in other natural evolving kinetic systems, selection of the fastest-growing stacks of tablets occurs gradually in space and time. These results suggest that the self-ordering of the mineral phase, which may occur completely independently of biological or organic-molecule control, is fundamental in nacre formation.

  13. Mechanical properties of nacre and highly mineralized bone

    OpenAIRE

    Davies, P; Casinos, A.; Currey, J D; Zioupos, P

    2001-01-01

    We compared the mechanical properties of 'ordinary' bovine bone, the highly mineralized bone of the rostrum of the whale Mesoplodon densirostris, and mother of pearl (nacre) of the pearl oyster Pinctada margaritifera. The rostrum and the nacre are similar in having very little organic material. However, the rostral bone is much weaker and more brittle than nacre, which in these properties is close to ordinary bone. The ability of nacre to outperform rostral bone is the result of its extremely...

  14. Multiscale structure of sheet nacre.

    Science.gov (United States)

    Rousseau, Marthe; Lopez, Evelyne; Stempflé, Philippe; Brendlé, Marcel; Franke, Loïc; Guette, Alain; Naslain, Roger; Bourrat, Xavier

    2005-11-01

    This work was conducted on Pinctada maxima nacre (mother of pearl) in order to understand its multiscale ordering and the role of the organic matrix in its structure. Intermittent-contact atomic force microscopy with phase detection imaging reveals a nanostructure within the tablet. A continuous organic framework divides each tablet into nanograins. Their shape is supposed to be flat with a mean extension of 45nm. TEM performed in the darkfield mode evidences that at least part of the intracrystalline matrix is crystallized and responds like a 'single crystal'. The tablet is a 'hybrid composite'. The organic matrix is continuous. The mineral phase is thus finely divided still behaving as a single crystal. It is proposed that each tablet results from the coherent aggregation of nanograins keeping strictly the same crystallographic orientation thanks to a hetero-epitaxy mechanism. Finally, high-resolution TEM performed on bridges from one tablet to the next, in the overlying row, did not permit to evidence a mineral lattice but crystallized organic bridges. The same organic bridges were evidenced by SEM in the interlaminar sequence. PMID:15907339

  15. Crystal nucleation and near-epitaxial growth in nacre

    CERN Document Server

    Olson, Ian C; Tamura, Nobumichi; Kunz, Martin; Gilbert, Pupa U P A

    2013-01-01

    Nacre, the iridescent inner lining of many mollusk shells, interests materials scientists because of its unique brick-and-mortar periodic structure at the sub-micron scale and its remarkable resistance to fracture. However, it remains unclear how nacre forms. Here we present 20-nm, 2{\\deg}-resolution Polarization-dependent Imaging Contrast (PIC) images of shells from 15 species, mapping nacre tablets and their orientation patterns, showing where crystals nucleate and how they grow in nacre. In all shells we found stacks of co-oriented aragonite (CaCO3) tablets arranged into vertical columns or staggered diagonally. Only near the nacre-prismatic boundary are disordered crystals nucleated, as spherulitic aragonite. Overgrowing nacre tablet crystals are most frequently co-oriented with the underlying spherulitic aragonite or with another tablet, connected by mineral bridges. Therefore aragonite crystal growth in nacre is epitaxial or near-epitaxial, with abrupt or gradual changes in orientation, with c-axes with...

  16. Bivalves build their shells from amorphous calcium carbonate

    Science.gov (United States)

    Jacob, D. E.; Wirth, R.; Soldati, A. L.; Wehrmeister, U.

    2012-04-01

    One of the most common shell structures in the bivalve class is the prism and nacre structure. It is widely distributed amongst both freshwater and marine species and gives cultured pearls their sought-after lustre. In freshwater bivalves, both shell structures (prism and nacre) consist of aragonite. Formation of the shell form an amorphous precursor phase is a wide-spread strategy in biomineralization and presents a number of advantages for the organisms in the handling of the CaCO3 material. While there is already evidence that larval shells of some mollusk species use amorphous calcium carbonate (ACC) as a transient precursor phase for aragonite, the use of this strategy by adult animals was only speculated upon. We present results from in-situ geochemistry, Raman spectroscopy and focused-ion beam assisted TEM on three species from two different bivalve families that show that remnants of ACC can be found in shells from adult species. We show that the amorphous phase is not randomly distributed, but is systematically found in a narrow zone at the interface between periostracum and prism layer. This zone is the area where spherulitic CaCO3- structures protrude from the inner periostracum to form the initial prisms. These observations are in accordance with our earlier results on equivalent structures in freshwater cultured pearls (Jacob et al., 2008) and show that the original building material for the prisms is amorphous calcium carbonate, secreted in vesicles at the inner periostracum layer. Quantitative temperature calibrations for paleoclimate applications using bivalve shells are based on the Mg-Ca exchange between inorganic aragonite (or calcite) and water. These calibrations, thus, do not take into account the biomineral crystallization path via an amorphous calcium carbonate precursor and are therefore likely to introduce a bias (a so-called vital effect) which currently is not accounted for. Jacob et al. (2008) Geochim. Cosmochim. Acta 72, 5401-5415

  17. Nacre-nanomimetics: Strong, Stiff, and Plastic.

    Science.gov (United States)

    De Luca, Francois; Menzel, Robert; Blaker, Jonny J; Birkbeck, John; Bismarck, Alexander; Shaffer, Milo S P

    2015-12-01

    The bricks and mortar in the classic structure of nacre have characteristic geometry, aspect ratios and relative proportions; these key parameters can be retained while scaling down the absolute length scale by more than 1 order of magnitude. The results shed light on fundamental scaling behavior and provide new opportunities for high performance, yet ductile, lightweight nanocomposites. Reproducing the toughening mechanisms of nacre at smaller length scales allows a greater volume of interface per unit volume while simultaneously increasing the intrinsic properties of the inorganic constituents. Layer-by-layer (LbL) assembly of poly(sodium 4-styrenesulfonate) (PSS) polyelectrolyte and well-defined [Mg2Al(OH)6]CO3.nH2O layered double hydroxide (LDH) platelets produces a dense, oriented, high inorganic content (∼90 wt %) nanostructure resembling natural nacre, but at a shorter length scale. The smaller building blocks enable the (self-) assembly of a higher quality nanostructure than conventional mimics, leading to improved mechanical properties, matching those of natural nacre, while allowing for substantial plastic deformation. Both strain hardening and crack deflection mechanisms were observed in situ by scanning electron microscopy (SEM) during nanoindentation. The best properties emerge from an ordered nanostructure, generated using regular platelets, with narrow size dispersion. PMID:26562352

  18. Restoration of stratum corneum with nacre lipids.

    Science.gov (United States)

    Rousseau, Marthe; Bédouet, Laurent; Lati, Elian; Gasser, Philippe; Le Ny, Karine; Lopez, Evelyne

    2006-09-01

    To discover potential new products for the atopic dermatitis treatment, lipids extracted from nacre from the oyster Pinctada margaritifera were tested on artificially dehydrated skin explants. Expression of filaggrin and transglutaminase 1 was investigated after treatment of dehydrated skin with P. margaritifera lipid extracts according to light microscopy after labelling with specific monoclonal antibodies. The lipids were extracted from the nacre with methanol/chloroform mixture at room temperature and the extract composition was determined according to TLC and densitometry measures. Relative to the dry nacre material, a yield of extraction in lipids of 0.54% (w/w) was determined. Fatty acids, triglycerides, cholesterol and ceramides were in low abundance. Then, application of lipid formulations on skin explants previously dehydrated gave after 3 h an overexpression of filaggrin and a decrease of transglutaminase expression as shown by light microscopy. Using immunofluorescence labelling, we showed that lipids extracted from the mother of pearl of P. margaritifera induced a reconstitution of the intercellular cement of the stratum corneum. The signaling properties of the nacre lipids could be used for a development of new active product treatment against the symptoms of the dermatitis. PMID:16877020

  19. Acoustic emission study of deformation behavior of nacre

    Science.gov (United States)

    Luo, Shunfei; Luo, Hongyun; Han, Zhiyuan

    2016-02-01

    A study on the acoustic emission (AE) characteristics during deformation of nacre material was performed. We found that intermittent AE events are generated during nacre deformation. These avalanches may be attributed to microfracture events of the aragonite (CaCO3) nano-asperities and bridges during tablet sliding. These events show several critical features, such as the power-law distributions of the avalanche sizes and interval. These results suggest that the underlying fracture dynamics during nacre deformation display a self-organized criticality (SOC). The results also imply that the disorder and long-range correlation between local microfracture events may play important roles in nacre deformation.

  20. Architecture of Columnar Nacre, and Implications for Its Formation Mechanism

    International Nuclear Information System (INIS)

    We analyze the structure of Haliotis rufescens nacre, or mother-of-pearl, using synchrotron spectromicroscopy and x-ray absorption near-edge structure spectroscopy. We observe imaging contrast between adjacent individual nacre tablets, arising because different tablets have different crystal orientations with respect to the radiation's polarization vector. Comparing previous data and our new data with models for columnar nacre growth, we find the data are most consistent with a model in which nacre tablets are nucleated by randomly distributed sites in the organic matrix layers

  1. Graphene-based artificial nacre nanocomposites.

    Science.gov (United States)

    Zhang, Yuanyuan; Gong, Shanshan; Zhang, Qi; Ming, Peng; Wan, Sijie; Peng, Jingsong; Jiang, Lei; Cheng, Qunfeng

    2016-05-01

    With its extraordinary properties as the strongest and stiffest material ever measured and the best-known electrical conductor, graphene could have promising applications in many fields, especially in the area of nanocomposites. However, processing graphene-based nanocomposites is very difficult. So far, graphene-based nanocomposites exhibit rather poor properties. Nacre, the gold standard for biomimicry, provides an excellent example and guidelines for assembling two-dimensional nanosheets into high performance nanocomposites. The inspiration from nacre overcomes the bottleneck of traditional approaches for constructing nanocomposites, such as poor dispersion, low loading, and weak interface interactions. This tutorial review summarizes recent research on graphene-based artificial nacre nanocomposites and focuses on the design of interface interactions and synergistic effects for constructing high performance nanocomposites. This tutorial review also focuses on a perspective of the dynamic area of graphene-based nanocomposites, commenting on whether the concept is viable and practical, on what has been achieved to date, and most importantly, what is likely to be achieved in the future. PMID:27039951

  2. Sheet nacre growth mechanism: a Voronoi model.

    Science.gov (United States)

    Rousseau, Marthe; Lopez, Evelyne; Couté, Alain; Mascarel, Gérard; Smith, David C; Naslain, Roger; Bourrat, Xavier

    2005-02-01

    Shell nacre (mother of pearl) of Pinctada margaritifera was analyzed by scanning electron microscopy. The originality of this work concerns the sampling performed to observe incipient nacre on the mantle side. The whole animal is embedded in methyl methacrylate followed by separation of the shell from the hardened mantle. It is revealed this way how each future nacre layer pre-exists as a film or compartment. Experimental observations also show for the first time, the progressive lateral crystallization inside this film, finishing under the form of a non-periodic pattern of polygonal tablets of bio-aragonite. It is evidenced that nuclei appear in the film in the vicinity of the zone where aragonite tablets of the underlying layer get in contact to each other. A possible explanation is given to show how nucleation is probably launched in time and space by a signal coming from the underlying layer. Finally, it is evidenced that tablets form a Voronoi tiling of the space: this suggests that their growth is controlled by an "aggregation-like" process of "crystallites" and not directly by the aragonite lattice growth. PMID:15681231

  3. Voyaging around nacre with the X-ray shuttle: From bio-mineralisation to prosthetics via mollusc phylogeny

    International Nuclear Information System (INIS)

    Research highlights: → Nacre could be a non ancestral form of calcium carbonate in molluscs. → Texture terms as useful links to ancestors in classification. → X-ray diffraction useful for biomineralisation, phylogeny, cladistic and implantology. → Farming conditions do not influence much shell growth. → Electrodeposition of aragonite as future technique for implant coating. - Abstract: Strong textures of mollusc shell layers are utilised to provide phylogenetic information. Aragonitic and calcitic layers are the targets here, inside which nacre layers, but not only, play a specific role. At the light of the texture patterns and a parcimonious approach, nacre appears not as an ancestral form of calcium carbonate in mollusc layers. Also, from texture terms we can propose some links to ancestral fossilised species. The aragonite unit-cell distortions due to macromolecule complex insertions in the microstructures are measured on raw specimens for several aragonite layers of gastropods and bivalves. The textural information is used to provide precise structural determination of the biogenic aragonite. Such information might provide useful lights on the biomineralisation processes in the future, in cladistic approaches. Farming conditions are shown not to influence much shell textures of Helix aspersa aspersa. Closely related species exhibit globally close textures, among which three are good candidates for bone neogeneration and which textures are identical. Electrodeposition of aragonite, with inclusion of molecular extract from shell species, results in nacre-like layers exhibiting structural distortions similar to known inductive layers. X-ray diffraction experiments are shown to provide invaluable insights in testing biomineralisation and phylogenetic hypotheses.

  4. Final critical habitat for Orange-nacre Mucket (Lampsilis perovalis)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Polygon shapefile of critical habitat for the Orange-nacre Mucket (Lampsilis perovalis) based on the description provided in the Federal Register.

  5. Mechanical properties of nacre and highly mineralized bone.

    Science.gov (United States)

    Currey, J D; Zioupos, P; Davies, P; Casino, A

    2001-01-01

    We compared the mechanical properties of 'ordinary' bovine bone, the highly mineralized bone of the rostrum of the whale Mesoplodon densirostris, and mother of pearl (nacre) of the pearl oyster Pinctada margaritifera. The rostrum and the nacre are similar in having very little organic material. However, the rostral bone is much weaker and more brittle than nacre, which in these properties is close to ordinary bone. The ability of nacre to outperform rostral bone is the result of its extremely well-ordered microstructure, with organic material forming a nearly continuous jacket round all the tiny aragonite plates, a design well adapted to produce toughness. In contrast, in the rostrum the organic material, mainly collagen, is poorly organized and discontinuous, allowing the mineral to join up to form, in effect, a brittle stony material. PMID:12123292

  6. On flaw tolerance of nacre: a theoretical study.

    Science.gov (United States)

    Shao, Yue; Zhao, Hong-Ping; Feng, Xi-Qiao

    2014-03-01

    As a natural composite, nacre has an elegant staggered 'brick-and-mortar' microstructure consisting of mineral platelets glued by organic macromolecules, which endows the material with superior mechanical properties to achieve its biological functions. In this paper, a microstructure-based crack-bridging model is employed to investigate how the strength of nacre is affected by pre-existing structural defects. Our analysis demonstrates that owing to its special microstructure and the toughening effect of platelets, nacre has a superior flaw-tolerance feature. The maximal crack size that does not evidently reduce the tensile strength of nacre is up to tens of micrometres, about three orders higher than that of pure aragonite. Through dimensional analysis, a non-dimensional parameter is proposed to quantify the flaw-tolerance ability of nacreous materials in a wide range of structural parameters. This study provides us some inspirations for optimal design of advanced biomimetic composites. PMID:24402917

  7. Nanotribology of nacre: Anisotropic dissipation in a multiscale hybrid material

    OpenAIRE

    Stempflé, Philippe; Bourrat, Xavier; Rousseau, Marthe; Lopez, Evelyne; Takadoum, Jamal

    2013-01-01

    Sheet nacre (so-called mother-of-pearl) is a hybrid biocomposite with a multiscale structure including nanograins of calcium carbonate (97 wt%-40 nm in size) and two organic matrices: (i) the "intracrystalline" (mainly composed by silk-fibroin-like proteins), and (ii) the "interlaminar" one (mainly composed of β-chitin and proteins). Micro/nanotribological behaviour was investigated on sheet nacre displaying various configurations (so-called face-on and edge-on), by varying the orientation of...

  8. Can bivalve veligers escape feeding currents of adult bivalves?

    NARCIS (Netherlands)

    Troost, K.; Veldhuizen, R.; Stamhuis, E.J.; Wolff, W.J.

    2008-01-01

    While the stock of introduced Pacific oysters (Crassostrea gigas) increased in the Oosterschelde estuary (SW Netherlands), so did the filtration pressure of all bivalve species together. In the same period, stocks of native bivalves declined slightly. The expansion of Pacific oysters in Dutch estuar

  9. Uncovering high-strain rate protection mechanism in nacre

    OpenAIRE

    Huang, Zaiwang; Li, Haoze; Pan, Zhiliang; Wei, Qiuming; Chao, Yuh J.; Li, Xiaodong

    2011-01-01

    Under high-strain-rate compression (strain rate ∼103 s−1), nacre (mother-of-pearl) exhibits surprisingly high fracture strength vis-à-vis under quasi-static loading (strain rate 10−3 s−1). Nevertheless, the underlying mechanism responsible for such sharply different behaviors in these two loading modes remains completely unknown. Here we report a new deformation mechanism, adopted by nacre, the best-ever natural armor material, to protect itself against predatory penetrating impacts. It invol...

  10. Novel basic protein, PfN23, functions as key macromolecule during nacre formation.

    Science.gov (United States)

    Fang, Dong; Pan, Cong; Lin, Huijuan; Lin, Ya; Zhang, Guiyou; Wang, Hongzhong; He, Maoxian; Xie, Liping; Zhang, Rongqing

    2012-05-01

    The fine microstructure of nacre (mother of pearl) illustrates the beauty of nature. Proteins found in nacre were believed to be "natural hands" that control nacre formation. In the classical view of nacre formation, nucleation of the main minerals, calcium carbonate, is induced on and by the acidic proteins in nacre. However, the basic proteins were not expected to be components of nacre. Here, we reported that a novel basic protein, PfN23, was a key accelerator in the control over crystal growth in nacre. The expression profile, in situ immunostaining, and in vitro immunodetection assays showed that PfN23 was localized within calcium carbonate crystals in the nacre. Knocking down the expression of PfN23 in adults via double-stranded RNA injection led to a disordered nacre surface in adults. Blocking the translation of PfN23 in embryos using morpholino oligomers led to the arrest of larval development. The in vitro crystallization assay showed that PfN23 increases the rate of calcium carbonate deposition and induced the formation of aragonite crystals with characteristics close to nacre. In addition, we constructed the peptides and truncations of different regions of this protein and found that the positively charged C-terminal region was a key region for the function of PfN23 Taken together, the basic protein PfN23 may be a key accelerator in the control of crystal growth in nacre. This provides a valuable balance to the classic view that acidic proteins control calcium carbonate deposition in nacre. PMID:22416139

  11. Novel Basic Protein, PfN23, Functions as Key Macromolecule during Nacre Formation*

    Science.gov (United States)

    Fang, Dong; Pan, Cong; Lin, Huijuan; Lin, Ya; Zhang, Guiyou; Wang, Hongzhong; He, Maoxian; Xie, Liping; Zhang, Rongqing

    2012-01-01

    The fine microstructure of nacre (mother of pearl) illustrates the beauty of nature. Proteins found in nacre were believed to be “natural hands” that control nacre formation. In the classical view of nacre formation, nucleation of the main minerals, calcium carbonate, is induced on and by the acidic proteins in nacre. However, the basic proteins were not expected to be components of nacre. Here, we reported that a novel basic protein, PfN23, was a key accelerator in the control over crystal growth in nacre. The expression profile, in situ immunostaining, and in vitro immunodetection assays showed that PfN23 was localized within calcium carbonate crystals in the nacre. Knocking down the expression of PfN23 in adults via double-stranded RNA injection led to a disordered nacre surface in adults. Blocking the translation of PfN23 in embryos using morpholino oligomers led to the arrest of larval development. The in vitro crystallization assay showed that PfN23 increases the rate of calcium carbonate deposition and induced the formation of aragonite crystals with characteristics close to nacre. In addition, we constructed the peptides and truncations of different regions of this protein and found that the positively charged C-terminal region was a key region for the function of PfN23 Taken together, the basic protein PfN23 may be a key accelerator in the control of crystal growth in nacre. This provides a valuable balance to the classic view that acidic proteins control calcium carbonate deposition in nacre. PMID:22416139

  12. Reducing effect of feeding powdered nacre of Pinctada maxima on the visceral fat of rats.

    Science.gov (United States)

    Shono, Masayuki; Shimizu, Ichiro; Aoyagi, Eriko; Taniguchi, Tatsuya; Takenaka, Hidetaka; Ishikawa, Momoko; Urata, Mari; Sannomiya, Katsutaka; Tamaki, Katsuyoshi; Harada, Nagakatsu; Nakaya, Yutaka; Takayama, Tetsuji

    2008-10-01

    An abdominal fat accumulation complicated by high blood triglycerides is regarded as a risk factor of metabolic syndrome. Feeding powdered nacre, mother of pearl, from Pinctada maxima, resulted in reduced body weight, visceral fat amount, and blood triglyceride level without influencing the food intake, body length, or amount of muscular tissue, suggesting that nacre powder specifically could decrease visceral fat. PMID:18838791

  13. Towards an Understanding of the Role of Aragonite in the Mechanical Properties of Nacre

    Energy Technology Data Exchange (ETDEWEB)

    2010-08-25

    Nacre, also known as mother-of-pearl, is a biocomposite material that exhibits higher strength and fracture toughness than its component materials. It derives its strength from the brick-and-mortar layering of aragonite (CaCO{sub 3}) platelets and organic binder. It is believed that the protein binder helps redistribute the stress throughout all tablets for optimal mechanical performance. In this study, we attempt to measure the mechanical properties of aragonite within nacre and compare them to bulk aragonite and bulk nacre and understand the redistribution of stresses. Here we show that x-ray diffraction techniques are useful for isolating and measuring strain of crystallites within a composite material. Our results show that the apparent stiffness of aragonite varies with crystallographic directions and is higher than the stiffness of bulk nacre in all cases, meaning that aragonite tablets are exposed to less than the average bulk stress. The average force applied to the bulk sample is partitioned between the aragonite and the binder, so that the protein layer bears as much as 27.2% of the total applied force. Different crystallographic directions exhibit behaviors different than bulk aragonite or bulk nacre. These are related to texture of aragonite platelets (i.e. preferred orientations within nacre). By examining nacre, we can obtain a better understanding of the mechanical relationship between the ceramic and polymer in composite materials. We expect that x-ray diffraction will become the standard method for probing the mechanical properties of composite materials.

  14. Stimulation of bone marrow cells and bone formation by nacre: in vivo and in vitro studies.

    Science.gov (United States)

    Lamghari, M; Almeida, M J; Berland, S; Huet, H; Laurent, A; Milet, C; Lopez, E

    1999-08-01

    There is frequently a loss of vertebral bone due to disease or aging. Nacre (mother of pearl from the oyster Pinctada maxima) stimulates bone cell differentiation and bone formation in vitro and in vivo. Experimental bone defects were prepared in the vertebrae of sheep and used to test the suitability of nacre as an injectable osteogenic biomaterial for treating vertebral bone loss. Twenty-one cavities were prepared in the first four upper lumbar vertebrae of 11 sheep and filled with nacre powder. The lumbar vertebrae were removed after 1 to 12 weeks, embedded undecalcified in methacrylate, and processed for histological studies. The nacre slowly dissolved and the experimental cavities contained a large active cell population. By 12 weeks, the experimental cavity was occupied by newly matured bone trabeculae in contact with or adjacent to the dissolving nacre. The functional new bone trabeculae were covered with osteoid lined with osteoblasts, indicating continuing bone formation. The in vitro study on rat bone marrow explants cultured with a water-soluble extract of the nacre organic matrix also resulted in the stimulation of osteogenic bone marrow cells with enhanced alkaline phosphatase activity. Thus, both the in vivo and in vitro findings suggest that nacre contains one or more signal molecules capable of activating osteogenic bone marrow cells. PMID:10458284

  15. Stiffness Enhancement in Nacre-Inspired Nanocomposites due to Nanoconfinement

    Science.gov (United States)

    Shao, Chen; Keten, Sinan

    2015-11-01

    Layered assemblies of polymers and graphene derivatives employ nacre’s tested strategy of intercalating soft organic layers with hard crystalline domains. These layered systems commonly display elastic properties that exceed simple mixture rule predictions, but the molecular origins of this phenomenon are not well understood. Here we address this issue by quantifying the elastic behavior of nanoconfined polymer layers on a model layered graphene-polymer nanocomposite. Using a novel, validated coarse-grained molecular dynamics simulation approach, here we clearly show that the elastic properties of layered nanocomposites cannot be described by volume fraction considerations alone and depend strongly on both interfacial energy and nanostructure. We quantify the relative importance of polymer nanoconfinement and interfacial energy on polymer structure and elasticity, and illustrate the validity of our model for two polymers with different intrinsic elastic properties. Our theoretical model culminates in phase diagrams that accurately predict the elastic response of nacre-inspired nanocomposites by accounting for all material design parameters. Our findings provide widely applicable prescriptive guidelines for utilizing nanoconfinement to improve the mechanical properties of layer-by-layer nanocomposites. Our findings also serve to explain why the elastic properties of organic layers in nacre exhibit multifold differences from the native and extracted states.

  16. Elastic modulus of biopolymer matrix in nacre measured using coupled atomic force microscopy bending and inverse finite element techniques

    International Nuclear Information System (INIS)

    A novel approach combining the atomic force microscopy probing of nacre biopolymer strand and the inverse finite element analysis has been used to directly measure the elastic modulus of nacre biopolymer matrix. An elastic modulus of 11 ± 3 GPa was determined for the first time from the direct measurement of the nacre biopolymer matrix. This property is essential for a fundamental understanding of the roles that the biopolymer matrix plays in nacre's strengthening and toughening, and provides guidelines in selecting engineering polymers for biomimetic materials design and fabrication. Such coupled experimental and modeling techniques should find more applications in studying the mechanical behavior of biological materials. Highlights: → Modulus of nacre biopolymer was directly measured using AFM and inverse FEM. → An elastic modulus of 10.57 ± 2.56 GPa was determined for nacre biopolymer matrix. → New approach developed in this study is useful for testing of biological materials.

  17. Hierarchical assembly strategy and multiscale structural origin of exceptional mechanical performance in nacre

    Science.gov (United States)

    Huang, Zaiwang

    Nacre (mother of pearl) is a self-assembled hierarchical nanocomposite in possession of exquisite multiscale architecture and exceptional mechanical properties. Previous work has shown that the highly-ordered brick-mortar-like structure in nacre is assembled via epitaxial growth and the aragonite platelets are pure single-crystals. Our results challenge this conclusion and propose that nacre's individual aragonite platelets are constructed with highly-aligned aragonite nanoparticles mediated by screw dislocation and amorphous aggregation. The underlying physics mechanism why the aragonite nanoparticles choose highly-oriented attachment as its crystallization pathway is rationalized in terms of thermodynamics. The aragonite nanoparticle order-disorder transformation can be triggered by high temperature and mechanical deformation, which in turn confirms that the aragonite nanoparticles are basic building blocks for aragonite platelets. Particularly fascinating is the fracture toughness enhancement of nacre through exquisitely collecting mechanically inferior calcium carbonate (CaCO3) and biomolecules. The sandwich-like microarchitecture with a geometrically staggered arrangement can induce crack deflection along its biopolymer interface, thus significantly enhancing nacre's fracture toughness. Our new findings ambiguously demonstrate that, aside from crack deflection, the advancing crack can invade aragonite platelet, leaving a zigzag crack propagation pathway. These unexpected experimental observations disclose, for the first time, the inevitable structural role of aragonite platelets in enhancing nacre's fracture toughness. Simultaneously, the findings that the crack propagates in a zigzag manner within individual aragonite platelets overturn the previously well-established wisdom that considers aragonite platelets as brittle single-crystals. Moreover, we investigated the dynamical mechanical response of nacre under unixial compression. Our results show that the

  18. Theoretical characterization of a model of aragonite crystal orientation in red abalone nacre

    OpenAIRE

    Coppersmith, S N; Gilbert, P. U. P. A.; Metzler, R. A.

    2009-01-01

    Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in red abalone consists of layers of 400-nm thick aragonite crystalline tablets confined by organic matrix sheets, with the $(001)$ crystal axes of the aragonite tablets oriented to within $\\pm$ 12 degrees from the normal to the layer planes. Recent experiments demonstrate that this orientational order develops over a distance of tens of layers from the prismatic boundary at which nacre formation begins. Our previous si...

  19. Osteogenic differentiation of human bone marrow mesenchymal stem cells in hydrogel containing nacre powder.

    Science.gov (United States)

    Flausse, Alicia; Henrionnet, Christel; Dossot, Manuel; Dumas, Dominique; Hupont, Sébastien; Pinzano, Astrid; Mainard, Didier; Galois, Laurent; Magdalou, Jacques; Lopez, Evelyne; Gillet, Pierre; Rousseau, Marthe

    2013-11-01

    Nacre (or mother of pearl) can facilitate bone cell differentiation and can speed up their mineralization. Here we report on the capability of nacre to induce differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs) and the production of extracellular matrix. hBM-MSCs were encapsulated in an alginate hydrogel containing different concentrations of powdered nacre and cultured in the same environment until Day 28. Analysis of osteogenic gene expression, histochemistry, second harmonic generation (SHG) microscopy, and Raman scattering spectroscopy were used to characterize the synthesis of the extracellular matrix. In the presence of nacre powder, a significant increase in matrix synthesis from D21 in comparison with pure alginate was observed. Histochemistry revealed the formation of a new tissue composed of collagen fibers in the presence of nacre (immunostaining and SHG), and hydroxyapatite crystals (Raman) in the alginate beads. These results suggest that nacre is efficient in hBM-MSCs differentiation, extracellular matrix production and mineralization in alginate 3D biomaterials. PMID:23554327

  20. Bone reactions to nacre injected percutaneously into the vertebrae of sheep.

    Science.gov (United States)

    Lamghari, M; Berland, S; Laurent, A; Huet, H; Lopez, E

    2001-03-01

    We have studied the osteogenic effects of nacre (mother of pearl) placed in experimental cavities prepared in the lumbar vertebrae of sheep. Some of cavities were filled with nacre, some with PMMA, and some were left empty. The vertebrae were removed 1, 8, 12 weeks after surgery, and assessed histologically and morphometrically. The nacre particles in the bone cavity and the surrounding intertrabecular spaces gradually dissolved beginning at 8 weeks after surgery. There were layers of newly formed bone, both woven and lamellar, in various stages of maturation in contact with or adjacent to the dissolving nacre. Quantitative assessment of the activation of bone formation adjacent to the cavities filled with nacre indicated significant activation of bone formation, which continued until week 12. There was also increased mineralization of the host bone at this time. There was no new bone formation in the empty cavities, or in those filled with PMMA. PMMA also caused necrosis of surrounding bone cells with a change in bone architecture and significant reductions in bone formation and mineralization. This study demonstrates that nacre stimulates bone-forming cells in vertebrae and appears to result in new bone formation. PMID:11219719

  1. Galeommatid bivalves from Phuket, Thailand

    DEFF Research Database (Denmark)

    Lützen, Jørgen; Nielsen, Claus

    2005-01-01

    Twenty-seven species of galeommatid bivalves from six genera have been collected at intertidal reef flats near Phuket Marine Biological Center, Thailand (Andaman Sea, Indian Ocean). Fourteen of the species are new to science and a new genus (Nudiscintilla gen. nov.) has been established. The...... crustacean, the remainder hide under shale, rocks and coral blocks, often in small intra- or interspecific family flocks. The behaviour was also noted for some of the species. It is presumed that galeommatid species go through a lengthy planktonic phase....

  2. Neoplastic diseases of marine bivalves.

    Science.gov (United States)

    Carballal, María J; Barber, Bruce J; Iglesias, David; Villalba, Antonio

    2015-10-01

    Two types of prevalent neoplastic diseases have been described in marine bivalves of commercial interest: disseminated neoplasia (DN) and gonadal neoplasia. The first involves the excessive proliferation of abnormal cells with unknown origin (probably of hemic source in some cases/species), disseminating through the circulatory system and infiltrating the connective tissue of various organs; the second consists of an abnormal proliferation of undifferentiated germinal cells of the gonad. These two types of bivalve neoplasia fit the criteria of malignant tumors: pleomorphic and undifferentiated cells, rapid and invasive growth, abundance of mitotic figures, metastasis and progressive development often resulting in the death of the affected individual. Different causes have been suggested regarding etiology: genetic alterations, virus, retrotranspons, and contaminants, although it could depend on the mollusk species; evidence of horizontal transmission of clonal cancer cells as the cause of DN spreading in clam Mya arenaria populations has been recently reported. In some species and populations, the neoplastic disorders affect only a few individuals, but in others reach high prevalence. Among the diagnostic methods, DN has been detected by histology and cytologic examination of hemolymph, and with developed specific antibodies. Recently, flow cytometry has also been applied, allowing detecting DNA quantity alteration. Several studies reported many genes and pathways critically involved in neoplastic transformation in Mya arenaria, Mytilus spp. and Ostrea edulis. These genetic studies will allow the development of diagnosis by PCR which can be used in biomonitoring studies. PMID:26146225

  3. Synergistic Biomineralization Phenomena Created by a Combinatorial Nacre Protein Model System.

    Science.gov (United States)

    Chang, Eric P; Roncal-Herrero, Teresa; Morgan, Tamara; Dunn, Katherine E; Rao, Ashit; Kunitake, Jennie A M R; Lui, Susan; Bilton, Matthew; Estroff, Lara A; Kröger, Roland; Johnson, Steven; Cölfen, Helmut; Evans, John Spencer

    2016-04-26

    In the nacre or aragonite layer of the mollusk shell, proteomes that regulate both the early stages of nucleation and nano-to-mesoscale assembly of nacre tablets from mineral nanoparticle precursors exist. Several approaches have been developed to understand protein-associated mechanisms of nacre formation, yet we still lack insight into how protein ensembles or proteomes manage nucleation and crystal growth. To provide additional insights, we have created a proportionally defined combinatorial model consisting of two nacre-associated proteins, C-RING AP7 (shell nacre, Haliotis rufescens) and pseudo-EF hand PFMG1 (oyster pearl nacre, Pinctada fucata), whose individual in vitro mineralization functionalities are well-documented and distinct from one another. Using scanning electron microscopy, flow cell scanning transmission electron microscopy, atomic force microscopy, Ca(II) potentiometric titrations, and quartz crystal microbalance with dissipation monitoring quantitative analyses, we find that both nacre proteins are functionally active within the same mineralization environments and, at 1:1 molar ratios, synergistically create calcium carbonate mesoscale structures with ordered intracrystalline nanoporosities, extensively prolong nucleation times, and introduce an additional nucleation event. Further, these two proteins jointly create nanoscale protein aggregates or phases that under mineralization conditions further assemble into protein-mineral polymer-induced liquid precursor-like phases with enhanced ACC stabilization capabilities, and there is evidence of intermolecular interactions between AP7 and PFMG1 under these conditions. Thus, a combinatorial model system consisting of more than one defined biomineralization protein dramatically changes the outcome of the in vitro biomineralization process. PMID:27072850

  4. Multiscale deformations lead to high toughness and circularly polarized emission in helical nacre-like fibres

    Science.gov (United States)

    Zhang, Jia; Feng, Wenchun; Zhang, Huangxi; Wang, Zhenlong; Calcaterra, Heather A.; Yeom, Bongjun; Hu, Ping An; Kotov, Nicholas A.

    2016-02-01

    Nacre-like composites have been investigated typically in the form of coatings or free-standing sheets. They demonstrated remarkable mechanical properties and are used as ultrastrong materials but macroscale fibres with nacre-like organization can improve mechanical properties even further. The fiber form or nacre can, simplify manufacturing and offer new functional properties unknown yet for other forms of biomimetic materials. Here we demonstrate that nacre-like fibres can be produced by shear-induced self-assembly of nanoplatelets. The synergy between two structural motifs--nanoscale brick-and-mortar stacking of platelets and microscale twisting of the fibres--gives rise to high stretchability (>400%) and gravimetric toughness (640 J g-1). These unique mechanical properties originate from the multiscale deformation regime involving solid-state self-organization processes that lead to efficient energy dissipation. Incorporating luminescent CdTe nanowires into these fibres imparts the new property of mechanically tunable circularly polarized luminescence. The nacre-like fibres open a novel technological space for optomechanics of biomimetic composites, while their continuous spinning methodology makes scalable production realistic.

  5. Nacre biomimetic design—A possible approach to prepare low infrared emissivity composite coatings

    International Nuclear Information System (INIS)

    Mimicking the highly organized brick-and-mortar structure of nacre, a kind of nacre-like organic–inorganic composite material of polyurethane (PU)/flaky bronze composite coatings with low infrared emissivity was successfully designed and prepared by using PU and flaky bronze powders as adhesives and pigments, respectively. The infrared emissivity and microstructure of the coatings were systematically investigated by infrared emissometer and scanning electron microscopy, respectively, and the cause of low infrared emissivity of the coatings was discussed by using the theories of one-dimensional photonic structure. The results show that the infrared emissivity of the nacre-like PU/flaky bronze composite coatings can be as low as 0.206 at the bronze content of 60 wt. %, and it is significantly lower than the value of PU/sphere bronze composite coatings. Microstructure observation illustrated that the nacre-like PU/flaky bronze composite coatings have similar one-dimensional photonic structural characteristics. The low infrared emissivity of PU/flaky bronze composite coatings is derived from the similar one-dimensional photonic structure in the coatings. Highlights: ► Nacre-like composite coatings with low infrared emissivity were prepared. ► Infrared emissivity of PU/flaky bronze composite coatings can be as low as 0.206. ► One-dimensional photonic structure is the cause for low emissivity of the coatings.

  6. Nacre biomimetic design-A possible approach to prepare low infrared emissivity composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weigang, E-mail: abczwg15@163.com; Xu, Guoyue; Ding, Ruya; Duan, Kaige; Qiao, Jialiang

    2013-01-01

    Mimicking the highly organized brick-and-mortar structure of nacre, a kind of nacre-like organic-inorganic composite material of polyurethane (PU)/flaky bronze composite coatings with low infrared emissivity was successfully designed and prepared by using PU and flaky bronze powders as adhesives and pigments, respectively. The infrared emissivity and microstructure of the coatings were systematically investigated by infrared emissometer and scanning electron microscopy, respectively, and the cause of low infrared emissivity of the coatings was discussed by using the theories of one-dimensional photonic structure. The results show that the infrared emissivity of the nacre-like PU/flaky bronze composite coatings can be as low as 0.206 at the bronze content of 60 wt. %, and it is significantly lower than the value of PU/sphere bronze composite coatings. Microstructure observation illustrated that the nacre-like PU/flaky bronze composite coatings have similar one-dimensional photonic structural characteristics. The low infrared emissivity of PU/flaky bronze composite coatings is derived from the similar one-dimensional photonic structure in the coatings. Highlights: Black-Right-Pointing-Pointer Nacre-like composite coatings with low infrared emissivity were prepared. Black-Right-Pointing-Pointer Infrared emissivity of PU/flaky bronze composite coatings can be as low as 0.206. Black-Right-Pointing-Pointer One-dimensional photonic structure is the cause for low emissivity of the coatings.

  7. Physical and chemical characterization of adsorbed protein onto gold electrode functionalized with Tunisian coral and nacre

    Energy Technology Data Exchange (ETDEWEB)

    Hamza, Samir, E-mail: samir.hamza@insat.rnu.tn [Biomaterials and Biomechanics Laboratory, National Institute M.T. Kassab of Orthopedic, 2010 La Manouba, Tunis (Tunisia); National Institute of Applied Sciences and Technology, Centre Urbain Nord, Box 676, 1080 Tunis cedex (Tunisia); Bouchemi, Meryem, E-mail: bouchemimeryem@yahoo.fr [National Institute of Applied Sciences and Technology, Centre Urbain Nord, Box 676, 1080 Tunis cedex (Tunisia); Slimane, Noureddine, E-mail: labiomecanique@yahoo.fr [Biomaterials and Biomechanics Laboratory, National Institute M.T. Kassab of Orthopedic, 2010 La Manouba, Tunis (Tunisia); Azari, Zitouni, E-mail: azari@univ-metz.fr [Laboratory of Biomechanics, Polymer and Structures Mechanics, National School of Engineers of Metz, France, 1 route d' Ars Laquenexy, CS 65820 57078 Metz cedex 03 (France)

    2013-01-01

    Bone substitutes are more and more used in bone surgery because of their biologic safety, clinic efficiency and facility to synthesize. Bone substitutes with active osteogenic properties, associating biomaterials with organic macromolecule components of the extracellular matrix (protein, GAG) are recommended. Nevertheless, we should have a simple technique to control interactions between proteins and the material. Natural coral and nacre have been found to be impressive bone graft substitutes. In this work, we characterize nacre and coral powder using energy dispersive X-ray analysis (EDX). We used electrochemical impedance spectroscopy (EIS) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to evaluate bovine serum albumin (BSA) as model protein, adsorbed to these biomaterial surfaces. In order to understand the nacre/coral-protein interfacial compatibility, it is necessary to investigate the wettability. - Highlights: Black-Right-Pointing-Pointer The structural and physico-chemical properties of material operated as a bone substitute. Black-Right-Pointing-Pointer This study investigated the adsorption of BSA onto coral and nacre. Black-Right-Pointing-Pointer X-ray diffraction analysis of coral and nacre. Black-Right-Pointing-Pointer Simple technique to control interactions between proteins and the biomaterial.

  8. Nacre-like calcium carbonate controlled by ionic liquid/graphene oxide composite template

    International Nuclear Information System (INIS)

    Nacre-like calcium carbonate nanostructures have been mediated by an ionic liquid (IL)-graphene oxide (GO) composite template. The resultant crystals were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and X-ray powder diffractometry (XRD). The results showed that either 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) or graphene oxide can act as a soft template for calcium carbonate formation with unusual morphologies. Based on the time-dependent morphology changes of calcium carbonate particles, it is concluded that nacre-like calcium carbonate nanostructures can be formed gradually utilizing [BMIM]BF4/GO composite template. During the process of calcium carbonate formation, [BMIM]BF4 acted not only as solvents but also as morphology templates for the fabrication of calcium carbonate materials with nacre-like morphology. Based on the observations, the possible mechanisms were also discussed. - Highlights: • Nacre-like CaCO3/GO were prepared by gas diffusion. • Ionic liquid/GO served as composite templates. • The interaction of Ca2+ ions and GO played a very important role in the formation of nacre-like CaCO3

  9. Nacre-inspired integrated strong and tough reduced graphene oxide-poly(acrylic acid) nanocomposites

    Science.gov (United States)

    Wan, Sijie; Hu, Han; Peng, Jingsong; Li, Yuchen; Fan, Yuzun; Jiang, Lei; Cheng, Qunfeng

    2016-03-01

    Inspired by the relationship between interface interactions and the high performance mechanical properties of nacre, a strong and tough nacre-inspired nanocomposite was demonstrated based on graphene oxide (GO) and polyacrylic acid (PAA) prepared via a vacuum-assisted filtration self-assembly process. The abundant hydrogen bonding between GO and PAA results in both high strength and toughness of the bioinspired nanocomposites, which are 2 and 3.3 times higher than that of pure reduced GO film, respectively. In addition, the effect of environmental relative humidity on the mechanical properties of bioinspired nanocomposites is also investigated, and is consistent with previous theoretical predictions. Moreover, this nacre-inspired nanocomposite also displays high electrical conductivity of 108.9 S cm-1. These excellent physical properties allow this type of nacre-inspired nanocomposite to be used in many applications, such as flexible electrodes, aerospace applications, and artificial muscles etc. This nacre-inspired strategy also opens an avenue for constructing integrated high performance graphene-based nanocomposites in the near future.

  10. Transcriptomic response to stress in marine bivalves

    Directory of Open Access Journals (Sweden)

    Q Li

    2013-10-01

    Full Text Available Marine bivalves have a set of unique capabilities to adapt to the complicated conditions owing to their habitats, living habits and feeding ways. Meanwhile, marine bivalves can be the biosensors to monitor the quality of the intertidal zones or other habitats. It is interesting for every biologist to find out the mechanisms by which organisms adapt to environmental challenges and the factors limiting their adaptive capacities. The development of biotechnology over the past few decades has provided biologists with a vast repertoire of biosensors that allow testing mRNA expression in response to environmental factors. This minireview is focused on the transcriptomic responses to abiotic and biotic stressors in bivalves and the relative methods to provide new perspectives as well as improve applications for bivalve biomonitoring studies.

  11. Acceleration of calcite kinetics by abalone nacre proteins

    Energy Technology Data Exchange (ETDEWEB)

    Fu, G; Qiu, S R; Orme, C A; Morse, D E; De Yoreo, J J

    2005-06-09

    The fascinating shapes and hierarchical designs of biomineralized structures have long been an inspiration to materials scientists because of the potential they suggest for biomolecular control over synthesis of crystalline materials. One prevailing view is that mineral-associated macromolecules are responsible for initiating and stabilizing non-equilibrium crystal polymorphs and morphologies through interactions between anionic moieties and cations in solution or at mineral surfaces. Indeed, numerous studies have demonstrated that bio-organic additives can dramatically alter crystal shapes and growth-rates in vitro. However, previous molecular-scale studies revealing mechanisms of growth modification focused on small molecules such as amino acids or peptides and always observed growth inhibition. In contrast, studies using full proteins were non-quantitative and underlying sources of growth modification were ill-defined. Here we investigate interactions between proteins isolated from abalone shell nacre and growing surfaces of calcite. We find that these proteins significantly accelerate the molecular-scale kinetics and, though much larger than atomic steps, alter growth morphology through step-specific interactions that lower their free energies. We propose that these proteins act as surfactants to promote ion attachment at calcite surfaces.

  12. Bioinspired Ternary Artificial Nacre Nanocomposites Based on Reduced Graphene Oxide and Nanofibrillar Cellulose.

    Science.gov (United States)

    Duan, Jianli; Gong, Shanshan; Gao, Yuan; Xie, Xiaolin; Jiang, Lei; Cheng, Qunfeng

    2016-04-27

    Inspired by the nacre, we demonstrated the integrated ternary artificial nacre nanocomposites through synergistic toughening of graphene oxide (GO) and nanofibrillar cellulose (NFC). In addition, the covalent bonding was introduced between adjacent GO nanosheets. The synergistic toughening effects from building blocks of one-dimensional NFC and two-dimensional GO, interface interactions of hydrogen and covalent bonding together result in the integrated mechanical properties including high tensile strength, toughness, and fatigue life as well as high electrical conductivity. These extraordinary properties of the ternary synthetic nacre nanocomposites allow the support for advances in diverse strategic fields including stretchable electronics, transportation, and energy. Such bioinspired strategy also provides a new insight in designing novel multifunctional nanocomposites. PMID:27054460

  13. Biomimetic design of materials and biomaterials inspired by the structure of nacre.

    Science.gov (United States)

    Luz, Gisela M; Mano, João F

    2009-04-28

    The micro-architecture of nacre (mother of pearl) has been classically illustrated as a 'brick-and-mortar' arrangement. It is clear now that hierarchical organization and other structural features play an important role in the amazing mechanical properties of this natural nanocomposite. The more important structural characteristics and mechanical properties of nacre are exposed as a base that has inspired scientists and engineers to develop biomimetic strategies that could be useful in areas such as materials science, biomaterials development and nanotechnology. A strong emphasis is given on the latest advances on the synthetic design and production of nacre-inspired materials and coatings, in particular to be used in biomedical applications. PMID:19324725

  14. Fusion of nacre, mussel, and lotus leaf: bio-inspired graphene composite paper with multifunctional integration

    Science.gov (United States)

    Zhong, Da; Yang, Qinglin; Guo, Lin; Dou, Shixue; Liu, Kesong; Jiang, Lei

    2013-06-01

    Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide and as an adhesive, similar to the mortar in nacre, to crosslink the adjacent graphene. The resultant nacre-like graphene paper exhibited stable superhydrophobicity, self-cleaning, anti-corrosion, and remarkable mechanical properties underwater.Multifunctional integration is an inherent characteristic for biological materials with multiscale structures. Learning from nature is an effective approach for scientists and engineers to construct multifunctional materials. In nature, mollusks (abalone), mussels, and the lotus have evolved different and optimized solutions to survive. Here, bio-inspired multifunctional graphene composite paper was fabricated in situ through the fusion of the different biological solutions from nacre (brick-and-mortar structure), mussel adhesive protein (adhesive property and reducing character), and the lotus leaf (self-cleaning effect). Owing to the special properties (self-polymerization, reduction, and adhesion), dopamine could be simultaneously used as a reducing agent for graphene oxide and as an adhesive, similar to the mortar in nacre, to crosslink the adjacent graphene. The resultant nacre-like graphene paper exhibited stable superhydrophobicity, self

  15. Plastic deformation in nano-scale multilayer materials — A biomimetic approach based on nacre

    International Nuclear Information System (INIS)

    The paper reports about a biomimetic based comparison of deformation in magnetron sputtered multilayer coatings based on titanium (Ti), titanium nitride (TiN) and diamond-like carbon (DLC) layers and the deformation mechanisms in nacre of mollusc shells. Nacre as highly mineralized tissue combines high stiffness and hardness with high toughness, enabling resistance to fracture and crack propagation during tensile loading. Such behaviour is based on a combination of load transmission by tensile stressed aragonite tablets and shearing in layers between the tablets. Shearing in these polysaccharide and protein interlayers demands hydrated conditions. Otherwise, nacre has similar brittle behaviour to aragonite. To prevent shear failure, shear hardening occurs by progressive tablet locking due to wavy dovetail-like surface geometry of the tablets. Similar effects by shearing and strain hardening mechanisms were found for Ti interlayers between TiN and DLC layers in high-resolution transmission electron microscopy studies, performed in deformed zones beneath spherical indentations. 7 nm thin Ti films are sufficient for strong toughening of the whole multi-layered coating structure, providing a barrier for propagation of cracks, starting from tensile-stressed, hard, brittle TiN or DLC layers. - Highlights: • Biomimetic approach to TiN-diamond-like carbon (DLC) multilayers by sputtering • Investigation of deformation in/around hardness indents by HR-TEM • Plastic deformation with shearing in 7-nm thick Ti interlayers in TiN–DLC multilayers • Biomimetically comparable to nacre deformation

  16. Nacre biomimetic design--a possible approach to prepare low infrared emissivity composite coatings.

    Science.gov (United States)

    Zhang, Weigang; Xu, Guoyue; Ding, Ruya; Duan, Kaige; Qiao, Jialiang

    2013-01-01

    Mimicking the highly organized brick-and-mortar structure of nacre, a kind of nacre-like organic-inorganic composite material of polyurethane (PU)/flaky bronze composite coatings with low infrared emissivity was successfully designed and prepared by using PU and flaky bronze powders as adhesives and pigments, respectively. The infrared emissivity and microstructure of the coatings were systematically investigated by infrared emissometer and scanning electron microscopy, respectively, and the cause of low infrared emissivity of the coatings was discussed by using the theories of one-dimensional photonic structure. The results show that the infrared emissivity of the nacre-like PU/flaky bronze composite coatings can be as low as 0.206 at the bronze content of 60 wt. %, and it is significantly lower than the value of PU/sphere bronze composite coatings. Microstructure observation illustrated that the nacre-like PU/flaky bronze composite coatings have similar one-dimensional photonic structural characteristics. The low infrared emissivity of PU/flaky bronze composite coatings is derived from the similar one-dimensional photonic structure in the coatings. PMID:25428049

  17. Extraction and Purification of Matrix Protein from the Nacre of Pearl Oyster Pinctada fucata

    Institute of Scientific and Technical Information of China (English)

    MA Caiping; ZHANG Cen; NIE Yancheng; XIE Liping; ZHANG Rongqing

    2005-01-01

    A soluble matrix protein P14 with an apparent molecular mass of 14.5 kDa was isolated from fragmented nacre of pearl oysters (Pinctada fucata) treated with 10% NaOH solution to investigate the nacre matrix proteins and their effect on the CaCO3 crystal. The protein was characterized by gel exclusion chromatography and reversed-phase high performance liquid chromatography after demineralization by 10% acetic acid. The X-ray diffraction pattern of P14 crystals indicates that P14 plays an important role in nacre biomineralization. P14 can induce aragonite formation, stimulate CaCO3 crystal formation, and accelerate aragonite precipitation. Heating of the acid insoluble nacre residue, which was named conchiolin, in 10% sodium dodecyl sulfate solution supplemented with 10% β-mercaptoethanol solution for 10-20 min at about 100(C gave two other soluble proteins having molecular masses of 19.4 kDa and 25.0 kDa. The present study suggests that these two proteins are linked to the insoluble organic matrix by disulfide bridges because the extraction yield increases when β-mercaptoethanol is added to the medium.

  18. A laser-engraved glass duplicating the structure, mechanics and performance of natural nacre.

    Science.gov (United States)

    Valashani, Seyed Mohammad Mirkhalaf; Barthelat, Francois

    2015-04-01

    Highly mineralized biological materials such as nacre (mother of pearl), tooth enamel or conch shell boast unique and attractive combinations of stiffness, strength and toughness. The structures of these biological materials and their associated mechanisms are now inspiring new types of advanced structural materials. However, despite significant efforts, no bottom up fabrication method could so far match biological materials in terms of microstructural organization and mechanical performance. Here we present a new 'top down' strategy to tackling this fabrication problem, which consists in carving weak interfaces within a brittle material using a laser engraving technique. We demonstrate the method by fabricating and testing borosilicate glasses containing nacre-like microstructures infiltrated with polyurethane. When deformed, these materials properly duplicate the mechanisms of natural nacre: combination of controlled sliding of the tablets, accompanied with geometric hardening, strain hardening and strain rate hardening. The nacre-like glass is composed of 93 volume % (vol%) glass, yet 700 times tougher and breaks at strains as high as 20%. PMID:25822595

  19. Plastic deformation in nano-scale multilayer materials — A biomimetic approach based on nacre

    Energy Technology Data Exchange (ETDEWEB)

    Lackner, Juergen M., E-mail: juergen.lackner@joanneum.at [JOANNEUM RESEARCH Forschungsges.m.b.H., Institute for Surface Technologies and Photonics, Functional Surfaces, Leobner Strasse 94, A-8712 Niklasdorf (Austria); Waldhauser, Wolfgang [JOANNEUM RESEARCH Forschungsges.m.b.H., Institute for Surface Technologies and Photonics, Functional Surfaces, Leobner Strasse 94, A-8712 Niklasdorf (Austria); Major, Boguslaw; Major, Lukasz [Polish Academy of Sciences, Institute of Metallurgy and Materials Sciences, IMIM-PAN, ul. Reymonta 25, PL-30059 Krakow (Poland); Kot, Marcin [University of Science and Technology, AGH, Aleja Adama Mickiewicza 30, 30-059 Krakow (Poland)

    2013-05-01

    The paper reports about a biomimetic based comparison of deformation in magnetron sputtered multilayer coatings based on titanium (Ti), titanium nitride (TiN) and diamond-like carbon (DLC) layers and the deformation mechanisms in nacre of mollusc shells. Nacre as highly mineralized tissue combines high stiffness and hardness with high toughness, enabling resistance to fracture and crack propagation during tensile loading. Such behaviour is based on a combination of load transmission by tensile stressed aragonite tablets and shearing in layers between the tablets. Shearing in these polysaccharide and protein interlayers demands hydrated conditions. Otherwise, nacre has similar brittle behaviour to aragonite. To prevent shear failure, shear hardening occurs by progressive tablet locking due to wavy dovetail-like surface geometry of the tablets. Similar effects by shearing and strain hardening mechanisms were found for Ti interlayers between TiN and DLC layers in high-resolution transmission electron microscopy studies, performed in deformed zones beneath spherical indentations. 7 nm thin Ti films are sufficient for strong toughening of the whole multi-layered coating structure, providing a barrier for propagation of cracks, starting from tensile-stressed, hard, brittle TiN or DLC layers. - Highlights: • Biomimetic approach to TiN-diamond-like carbon (DLC) multilayers by sputtering • Investigation of deformation in/around hardness indents by HR-TEM • Plastic deformation with shearing in 7-nm thick Ti interlayers in TiN–DLC multilayers • Biomimetically comparable to nacre deformation.

  20. Oxidative stress and bivalves: a proteomic approach

    Directory of Open Access Journals (Sweden)

    B McDonagh

    2008-09-01

    Full Text Available Bivalves are of major importance in aquatic ecology, aquaculture, are widely used as sentinel species in environmental toxicology and show remarkable plasticity to molecular oxygen. Excess reactive oxygen species (ROS arising from molecular oxygen can cause oxidative stress and this is also a consequence of exposure to many common environmental pollutants. Indices of oxidative stress have therefore found favor as biomarkers of exposure and effect in environmental toxicology. However, there is a growing body of literature on the use of discovery-led proteomics methods to detect oxidative stress in bivalves. This is because proteins absorb up to 70 % of ROS leading to complication of the proteome. This article explores the background to these developments and assesses the practice and future potential of proteomics in the study of oxidative stress in bivalves.

  1. Integrated ternary artificial nacre via synergistic toughening of reduced graphene oxide/double-walled carbon nanotubes/poly(vinyl alcohol)

    Science.gov (United States)

    Gong, Shanshan; Wu, Mengxi; Jiang, Lei; Cheng, Qunfeng

    2016-07-01

    The synergistic toughening effect of building blocks and interface interaction exists in natural materials, such as nacre. Herein, inspired by one-dimensional (1D) nanofibrillar chitin and two-dimensional (2D) calcium carbonate platelets of natural nacre, we have fabricated integrated strong and tough ternary bio-inspired nanocomposites (artificial nacre) successfully via the synergistic effect of 2D reduced graphene oxide (rGO) nanosheets and 1D double-walled carbon nanotubes (DWNTs) and hydrogen bonding cross-linking with polyvinyl alcohol (PVA) matrix. Moreover, the crack mechanics model with crack deflection by 2D rGO nanosheets and crack bridging by 1D DWNTs and PVA chains induces resultant artificial nacre exhibiting excellent fatigue-resistance performance. These outstanding characteristics enable the ternary bioinspired nanocomposites have many promising potential applications, for instance, aerospace, flexible electronics devices and so forth. This synergistic toughening strategy also provides an effective way to assemble robust graphene-based nanocomposites.

  2. Use of Synergistic Interactions to Fabricate Strong, Tough, and Conductive Artificial Nacre Based on Graphene Oxide and Chitosan.

    Science.gov (United States)

    Wan, Sijie; Peng, Jingsong; Li, Yuchen; Hu, Han; Jiang, Lei; Cheng, Qunfeng

    2015-10-27

    Graphene is the strongest and stiffest material, leading to the development of promising applications in many fields. However, the assembly of graphene nanosheets into macrosized nanocomposites for practical applications remains a challenge. Nacre in its natural form sets the "gold standard" for toughness and strength, which serves as a guide to the assembly of graphene nanosheets into high-performance nanocomposites. Here we show the strong, tough, conductive artificial nacre based on graphene oxide through synergistic interactions of hydrogen and covalent bonding. Tensile strength and toughness was 4 and 10 times higher, respectively, than that of natural nacre. The exceptional integrated strong and tough artificial nacre has promising applications in aerospace, artificial muscle, and tissue engineering, especially for flexible supercapacitor electrodes due to its high electrical conductivity. The use of synergistic interactions is a strategy for the development of high-performance nanocomposites. PMID:26352293

  3. Bioinspired Hydroxyapatite/Poly(methyl methacrylate) Composite with a Nacre-Mimetic Architecture by a Bidirectional Freezing Method.

    Science.gov (United States)

    Bai, Hao; Walsh, Flynn; Gludovatz, Bernd; Delattre, Benjamin; Huang, Caili; Chen, Yuan; Tomsia, Antoni P; Ritchie, Robert O

    2016-01-01

    Using a bidirectional freezing technique, combined with uniaxial pressing and in situ polymerization, "nacre-mimetic" hydroxyapatite/poly(methyl methacrylate) (PMMA) composites are developed by processing large-scale aligned lamellar ceramic scaffolds. Structural and mechanical characterization shows "brick-and-mortar" structures, akin to nacre, with interesting combinations of strength, stiffness, and work of fracture, which provide a pathway to making strong and tough lightweight materials. PMID:26554760

  4. Ornaments in radiation treatment of cultural heritage: Color and UV-vis spectral changes in irradiated nacres

    Science.gov (United States)

    Marušić, Katarina; Pucić, Irina; Desnica, Vladan

    2016-07-01

    Cultural heritage objects that are radiation treated in order to stop their biodegradation often contain ornamenting materials that cannot be removed. Radiation may produce unwanted changes to such materials. Nacre is a common ornamenting material so this is an attempt to assess the impact of gamma-radiation on its optical properties. Two types of nacre (yellow and white) were obtained from a museum and subjected to different absorbed doses of Co-60 gamma irradiation under the same conditions. The radiation induced changes of nacres color were investigated with fiber optic reflectance spectroscopy (FORS). Colorimetry in CIE Lab space revealed that in both nacres the lightness shifted to darker grey hues at high doses while the color component's (red, green, yellow and blue) behavior depended on the nacre type. Observable changes occurred at doses much above the dose range needed for radiation treatment of cultural heritage objects that are often ornamented with nacre. In UV-vis reflectance spectra of samples irradiated to high doses carbonate radical anion absorption appeared.

  5. Influence of the Depth on the Shape and Thickness of Nacre Tablets of Pinctada margaritifera Pearl Oyster, and on Oxygen Isotopic Composition

    OpenAIRE

    Marthe Rousseau; Claire Rollion-Bard

    2012-01-01

    Nacre, or mother of pearl, is composed of aragonite tablets and is produced by some mollusks. Because of the highly organized internal structure, chemical complexity, mechanical properties and optical effects of nacre, its formation is among the best-studied examples of calcium carbonate biomineralization. The pearl oyster Pinctada margaritifera is harvested in French Polynesia for pearl farming. The quality of the pearl depends on the quality of the nacre on its surface and its iridescent co...

  6. Bivalve grazing can shape phytoplankton communities

    Science.gov (United States)

    Lucas, Lisa; Cloern, James E.; Thompson, Janet K.; Stacey, Mark T.; Koseff, Jeffrey K.

    2016-01-01

    The ability of bivalve filter feeders to limit phytoplankton biomass in shallow waters is well-documented, but the role of bivalves in shaping phytoplankton communities is not. The coupled effect of bivalve grazing at the sediment-water interface and sinking of phytoplankton cells to that bottom filtration zone could influence the relative biomass of sinking (diatoms) and non-sinking phytoplankton. Simulations with a pseudo-2D numerical model showed that benthic filter feeding can interact with sinking to alter diatom:non-diatom ratios. Cases with the smallest proportion of diatom biomass were those with the fastest sinking speeds and strongest bivalve grazing rates. Hydrodynamics modulated the coupled sinking-grazing influence on phytoplankton communities. For example, in simulations with persistent stratification, the non-sinking forms accumulated in the surface layer away from bottom grazers while the sinking forms dropped out of the surface layer toward bottom grazers. Tidal-scale stratification also influenced vertical gradients of the two groups in opposite ways. The model was applied to Suisun Bay, a low-salinity habitat of the San Francisco Bay system that was transformed by the introduction of the exotic clam Potamocorbula amurensis. Simulation results for this Bay were similar to (but more muted than) those for generic habitats, indicating that P. amurensis grazing could have caused a disproportionate loss of diatoms after its introduction. Our model simulations suggest bivalve grazing affects both phytoplankton biomass and community composition in shallow waters. We view these results as hypotheses to be tested with experiments and more complex modeling approaches.

  7. La Nacre, les biominéralisations et la pharmacopée

    OpenAIRE

    Lopez, Evelyne; Rousseau, Marthe; Bourrat, Xavier

    2008-01-01

    La Nacre n'a rien de commun avec les pierres précieuses comme le diamant qui est forgé à des centaines de kilomètres au cœur de la Terre. Rien de commun non plus avec le rubis né des forces tectoniques qui font surgir les montagnes. Non ! La Nacre est une structure fascinante produite par le monde vivant. Comment l'Évolution biologique a-t-elle réussi à produire ce joyau ? Cet article nous montre qu'il s'agit de l'aboutissement d'un long processus qui a commencé il y a des milliards d'années ...

  8. Stress and displacement around a crack in layered network systems mimicking nacre

    Science.gov (United States)

    Aoyanagi, Yuko; Okumura, Ko

    2009-06-01

    Nacre is a natural composite material which has been studied because of its remarkable structure and its strength. In this paper, we revisit a layered model of nacre proposed previously [K. Okumura and P. G. de Gennes, Eur. Phys. J. E 4, 121 (2001)] in order to understand the physical reasons for the toughening via numerical simulation. We construct a two-dimensional lattice model which reflects the layered structure and perform a numerical study. This grid model reproduces the essential features predicted by the analytical solutions to the previous model and the results elucidate the reasons why the tip-stress concentration is reduced and tip displacement is enhanced in the layered system.

  9. Nacre-like materials using a simple doctor blading technique: Fabrication, testing and modeling.

    Science.gov (United States)

    Mirkhalaf, M; Barthelat, F

    2016-03-01

    The remarkable mechanical performance of biological materials such as bone, nacre, and spider silk stems from their staggered microstructure in which stiff and strong reinforcements are elongated in the direction of loading, separated by softer interfaces, and shifted relative to each other. This structure results in useful combinations of modulus, strength and toughness and therefore is increasingly mimicked in bio-inspired engineering composites. Here, we report the use of a simple and versatile technique based on doctor-blading to fabricate staggered composites of microscopic alumina tablets with high alignment in a chitosan matrix. Tensile tests on these nacre-like materials show that the modulus and strength of the composite films are enhanced by the incorporation of ceramic tablets, but only up to 15vol% after which all properties degrade. This phenomenon, also reported in the past for most of nacre-like materials, composed of micro/nano tablets, obtained from different techniques, has been limiting our ability to produce large volumes of high-performance nacre-like materials. Examination of the structure of the films revealed that at lower tablet concentrations the tablets are well-aligned and well dispersed thorough the volume of the film. At 15vol% and beyond, we observed tablet misalignment and clustering. In order to investigate the impact of these imperfections on material performance we developed large scale finite element models representative of the structure of the composite films. These models show that the mechanical performance significantly degrades with tablet misalignment, and especially at high tablet concentrations. The simulations along with the SEM images therefore quantitatively explain the experimental trends, e.g. the degradation of mechanical properties at high tablet contents. PMID:26655459

  10. Fabricational morphology of oblique ribs in bivalves.

    Science.gov (United States)

    Checa, Antonio G

    2002-11-01

    The formation of oblique ribs of bivalve shells usually has been attributed to processes of reaction-diffusion of morphogens from cell to cell at the mantle margin or neural activation and lateral inhibition in the mantle. In particular, such ribs appear with high rates of lateral diffusion. Nevertheless, theoretical models fail to explain either partially or wholly some varieties of oblique ribs. After surveying the modes of formation of the shell and oblique ribs by the bivalve mantle and associated fabricational defects, I have determined that the mantle is able to develop an elaborate behavior in order to displace the rib in a particular direction during growth. The mantle margin is, therefore, not only the shell-secreting organ, but also the main morphogenetic unit. In particular, there are two main fabricational strategies. In forms with strict contact guidance (SCG) the mantle is able to project far enough beyond the shell margins so as to feel the already formed reliefs and to align new growth increments of the ribs in the appropriate directions. The shell margin is always strongly reflected. In bivalves with reduced contact guidance plus constant lateral shift (RCG), the margin is usually acute and the information about ribs available to the mantle is reduced. During rib construction the mantle extrudes slightly from the shell edge and then pushes laterally by muscular action; in this way, the new growth increment of the rib is displaced laterally on a small scale. The contact-guidance model is supported also by the homogeneous structure of the shell-secreting mantle. From the morphogenetic standpoint, oblique ribs are related to commarginal ones and both differ completely from other ribbing patterns of bivalves. PMID:12353301

  11. Artificial nacre-like papers based on noncovalent functionalized boron nitride nanosheets with excellent mechanical and thermally conductive properties.

    Science.gov (United States)

    Zeng, Xiaoliang; Ye, Lei; Yu, Shuhui; Li, Hao; Sun, Rong; Xu, Jianbin; Wong, Ching-Ping

    2015-04-21

    Inspired by the nano/microscale hierarchical structure and the precise inorganic/organic interface of natural nacre, we fabricated artificial nacre-like papers based on noncovalent functionalized boron nitride nanosheets (NF-BNNSs) and poly(vinyl alcohol) (PVA) via a vacuum-assisted self-assembly technique. The artificial nacre-like papers exhibit excellent tensile strength (125.2 MPa), on a par with that of the natural nacre, and moreover display a 30% higher toughness (2.37 MJ m(-3)) than that of the natural nacre. These excellent mechanical properties result from an ordered 'brick-and-mortar' arrangement of NF-BNNSs and PVA, in which the long-chain PVA molecules act as the bridge to link NF-BNNSs via hydrogen bonds. The resulting papers also render high thermal conductivity (6.9 W m(-1) K(-1)), and reveal their superiority as flexible substrates to support light-emitting-diode chips. The combined mechanical and thermal properties make the materials highly desirable as flexible substrates for next-generation commercial portable electronics. PMID:25807278

  12. Artificial nacre-like papers based on noncovalent functionalized boron nitride nanosheets with excellent mechanical and thermally conductive properties

    Science.gov (United States)

    Zeng, Xiaoliang; Ye, Lei; Yu, Shuhui; Li, Hao; Sun, Rong; Xu, Jianbin; Wong, Ching-Ping

    2015-04-01

    Inspired by the nano/microscale hierarchical structure and the precise inorganic/organic interface of natural nacre, we fabricated artificial nacre-like papers based on noncovalent functionalized boron nitride nanosheets (NF-BNNSs) and poly(vinyl alcohol) (PVA) via a vacuum-assisted self-assembly technique. The artificial nacre-like papers exhibit excellent tensile strength (125.2 MPa), on a par with that of the natural nacre, and moreover display a 30% higher toughness (2.37 MJ m-3) than that of the natural nacre. These excellent mechanical properties result from an ordered `brick-and-mortar' arrangement of NF-BNNSs and PVA, in which the long-chain PVA molecules act as the bridge to link NF-BNNSs via hydrogen bonds. The resulting papers also render high thermal conductivity (6.9 W m-1 K-1), and reveal their superiority as flexible substrates to support light-emitting-diode chips. The combined mechanical and thermal properties make the materials highly desirable as flexible substrates for next-generation commercial portable electronics.Inspired by the nano/microscale hierarchical structure and the precise inorganic/organic interface of natural nacre, we fabricated artificial nacre-like papers based on noncovalent functionalized boron nitride nanosheets (NF-BNNSs) and poly(vinyl alcohol) (PVA) via a vacuum-assisted self-assembly technique. The artificial nacre-like papers exhibit excellent tensile strength (125.2 MPa), on a par with that of the natural nacre, and moreover display a 30% higher toughness (2.37 MJ m-3) than that of the natural nacre. These excellent mechanical properties result from an ordered `brick-and-mortar' arrangement of NF-BNNSs and PVA, in which the long-chain PVA molecules act as the bridge to link NF-BNNSs via hydrogen bonds. The resulting papers also render high thermal conductivity (6.9 W m-1 K-1), and reveal their superiority as flexible substrates to support light-emitting-diode chips. The combined mechanical and thermal properties make

  13. Stimulation of rat cutaneous fibroblasts and their synthetic activity by implants of powdered nacre (mother of pearl).

    Science.gov (United States)

    Lopez, E; Le Faou, A; Borzeix, S; Berland, S

    2000-02-01

    The components of the cutaneous envelope, the epidermis and the dermis, change in response to aging or environmental stress factors. The fibroblasts involved in maintaining skin tone are the main targets. Nacre, mother of pearl, from Pinctada maxima, which can stimulate and regulate bone forming cells, was implanted in the dermis of rats to test its action on the skin fibroblasts. This report describes the effect of nacre on the skin fibroblast recruitment and physiological activity. It resulted in enhanced extracellular matrix synthesis and the production of components implicated in cell to cell adhesion and communication (such as decorine) and in tissue regeneration (type I and type III collagens). The nacre implant produced a well vascularized tissue. The physiological conditions in the region around the implant are thus those required for the positive interactions between the dermis and epidermis which are fundamental for the physiological function of the skin. PMID:10798323

  14. Phylogeny and diversification patterns among vesicomyid bivalves.

    Directory of Open Access Journals (Sweden)

    Carole Decker

    Full Text Available Vesicomyid bivalves are among the most abundant and diverse symbiotic taxa in chemosynthetic-based ecosystems: more than 100 different vesicomyid species have been described so far. In the present study, we investigated the phylogenetic positioning of recently described vesicomyid species from the Gulf of Guinea and their western Atlantic and Pacific counterparts using mitochondrial DNA sequence data. The maximum-likelihood (ML tree provided limited support for the recent taxonomic revision of vesicomyids based on morphological criteria; nevertheless, most of the newly sequenced specimens did not cluster with their morphological conspecifics. Moreover, the observed lack of geographic clustering suggests the occurrence of independent radiations followed by worldwide dispersal. Ancestral character state reconstruction showed a significant correlation between the characters "depth" and "habitat" and the reconstructed ML phylogeny suggesting possible recurrent events of 'stepwise speciation' from shallow to deep waters in different ocean basins. This is consistent with genus or species bathymetric segregation observed from recent taxonomic studies. Altogether, our results highlight the need for ongoing re-evaluation of the morphological characters used to identify vesicomyid bivalves.

  15. Theoretical characterization of a model of aragonite crystal orientation in red abalone nacre

    Energy Technology Data Exchange (ETDEWEB)

    Coppersmith, S N; Gilbert, P U P A; Metzler, R A [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)

    2009-03-27

    Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in red abalone consists of layers of 400 nm thick aragonite crystalline tablets confined by organic matrix sheets, with the [0 0 1] crystal axes of the aragonite tablets oriented to within {+-}12 deg. from the normal to the layer planes. Recent experiments demonstrate that greater orientational order develops over a distance of tens of layers from the prismatic boundary at which nacre formation begins. Our previous simulations of a model in which the order develops because of differential tablet growth rates (oriented tablets growing faster than misoriented ones) yield patterns of tablets that agree qualitatively and quantitatively with the experimental measurements. This paper presents an analytical treatment of this model, focusing on how the dynamical development and eventual degree of order depend on model parameters. Dynamical equations for the probability distributions governing tablet orientations are introduced whose form can be determined from symmetry considerations and for which substantial analytic progress can be made. Numerical simulations are performed to relate the parameters used in the analytic theory to those in the microscopic growth model. The analytic theory demonstrates that the dynamical mechanism is able to achieve a much higher degree of order than naive estimates would indicate.

  16. Theoretical characterization of a model of aragonite crystal orientation in red abalone nacre

    International Nuclear Information System (INIS)

    Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in red abalone consists of layers of 400 nm thick aragonite crystalline tablets confined by organic matrix sheets, with the [0 0 1] crystal axes of the aragonite tablets oriented to within ±12 deg. from the normal to the layer planes. Recent experiments demonstrate that greater orientational order develops over a distance of tens of layers from the prismatic boundary at which nacre formation begins. Our previous simulations of a model in which the order develops because of differential tablet growth rates (oriented tablets growing faster than misoriented ones) yield patterns of tablets that agree qualitatively and quantitatively with the experimental measurements. This paper presents an analytical treatment of this model, focusing on how the dynamical development and eventual degree of order depend on model parameters. Dynamical equations for the probability distributions governing tablet orientations are introduced whose form can be determined from symmetry considerations and for which substantial analytic progress can be made. Numerical simulations are performed to relate the parameters used in the analytic theory to those in the microscopic growth model. The analytic theory demonstrates that the dynamical mechanism is able to achieve a much higher degree of order than naive estimates would indicate

  17. A review of experimental techniques to produce a nacre-like structure

    International Nuclear Information System (INIS)

    The performance of man-made materials can be improved by exploring new structures inspired by the architecture of biological materials. Natural materials, such as nacre (mother-of-pearl), can have outstanding mechanical properties due to their complicated architecture and hierarchical structure at the nano-, micro- and meso-levels which have evolved over millions of years. This review describes the numerous experimental methods explored to date to produce composites with structures and mechanical properties similar to those of natural nacre. The materials produced have sizes ranging from nanometres to centimetres, processing times varying from a few minutes to several months and a different range of mechanical properties that render them suitable for various applications. For the first time, these techniques have been divided into those producing bulk materials, coatings and free-standing films. This is due to the fact that the material's application strongly depends on its dimensions and different results have been reported by applying the same technique to produce materials with different sizes. The limitations and capabilities of these methodologies have been also described. (topical review)

  18. Hierarchically roughened microplatelets enhance the strength and ductility of nacre-inspired composites.

    Science.gov (United States)

    Niebel, Tobias P; Carnelli, Davide; Binelli, Marco R; Libanori, Rafael; Studart, André R

    2016-07-01

    Rough interfaces featuring nanoscale asperities are known to play a major role in the mechanics of nacre. Transferring this concept to artificial bioinspired composites requires a detailed understanding about the effect of the surface topography of reinforcing elements on the mechanical performance of such materials. To gain further insights into the effect of asperity size, hierarchy and coverage on the mechanics of nacre-inspired composites, we decorate alumina microplatelets with silica nanoparticles of selected sizes and use the resulting roughened platelets as reinforcing elements (15vol%) in a commercial epoxy matrix. For a single layer of silica nanoparticles on the platelet surface, increased ultimate strain and toughness are obtained with a large roughening particle size of 250nm. On the contrary, strength and stiffness are enhanced by decreasing the size of asperities using 22nm silica particles. By combining particles of two different sizes (100nm and 22nm) in a hierarchical fashion, we are able to improve stiffness and strength of platelet-reinforced polymers while maintaining high ultimate strain and toughness. Our results indicate that carefully designed hierarchically roughened interfaces lead to a more homogeneous stress distribution within the polymer matrix between the stiff reinforcing elements. By enabling the deformation of a larger fraction of the polymer matrix, this design concept improves the mechanical response of bioinspired composites and can possibly also be exploited to enhance the performance of conventional fiber-reinforced polymers. PMID:26926989

  19. Overwiew on selective breeding and genetic improvement in bivalve shellfish

    OpenAIRE

    Boudry, Pierre

    2004-01-01

    Dr. Boudry focussed his talk on oysters, which are the most important bivalve species produced world wide (more than 4 million tons). One of the main characteristic of bivalve aquaculture is that most of the juveniles ("seed or "spat") are collected from natural recruitment (e.g. 100% of the European mussel production). Hatchery propagation is used in the case of introduced species (e.g. Crassostrea gigas in USA) or limited natural recruitment. The most significant genetic improvement ...

  20. Geography of end-Cretaceous marine bivalve extinctions

    Science.gov (United States)

    Raup, David M.; Jablonski, David

    1993-01-01

    Analysis of the end-Cretaceous mass extinction, based on 3514 occurrences of 340 genera of marine bivalves (Mollusca), suggests that extinction intensities were uniformly global; no latitudinal gradients or other geographic patterns are detected. Elevated extinction intensities in some tropical areas are entirely a result of the distribution of one extinct group of highly specialized bivalves, the rudists. When rudists are omitted, intensities at those localities are statistically indistinguishable from those of both the rudist-free tropics and extratropical localities.

  1. Lower Jurassic beds with bivalves in south Slovenia

    OpenAIRE

    Irena Debeljak; Stanko Buser

    1995-01-01

    The Lower Jurassic beds of south Slovenia outcrop on a surface of several hundred km^ with their thickness in places exceeding 300 meters. They were deposited on the Dinaric Carbonate Platform. In them rich accumulations of characteristic bivalves occur that in Pliensbachian and Toarcian inhabited the wide interconnected shallow water regions of the western and southern margins of Tethysand the eastern Pacific. The most interesting are three large bivalve species:Lithiotis problematica, Cochl...

  2. Characteristics of bivalve diversity in typical habitats of China seas

    OpenAIRE

    Fengshan Xu; Junlong Zhang

    2011-01-01

    With vast sea areas, long coastline and complex environmental conditions, the China seas contain various habitats for bivalves. The diversity characteristics of some typical habitats can reflect the molluscan fauna of China seas. Based on our years of work and records from malacologists home and abroad, the bi-valve diversity, habitats and ecological habits in different environments are described, and the distribution characters in different sea areas are analysed. Due to the effects of coast...

  3. Influence of the Depth on the Shape and Thickness of Nacre Tablets of Pinctada margaritifera Pearl Oyster, and on Oxygen Isotopic Composition

    Directory of Open Access Journals (Sweden)

    Marthe Rousseau

    2012-03-01

    Full Text Available Nacre, or mother of pearl, is composed of aragonite tablets and is produced by some mollusks. Because of the highly organized internal structure, chemical complexity, mechanical properties and optical effects of nacre, its formation is among the best-studied examples of calcium carbonate biomineralization. The pearl oyster Pinctada margaritifera is harvested in French Polynesia for pearl farming. The quality of the pearl depends on the quality of the nacre on its surface and its iridescent colors are affected by the thickness of the layers. Here we report on an experimental study conducted to influence the shape and the thickness of nacre tablets by keeping pearl oysters at four different depths (7, 20, 30 and 39 m for one week. Scanning electron microscopy was used to measure the thickness of the nacre tablets and to analyze their final shape. The shape of the tablets changed from hexagonal to rhomboid at a depth of 39 m. The change in shape led to a change in size. The thickness of the tablets was reduced by between 16 and 30% on average. We also measured the oxygen isotopic composition using Secondary Ion Mass Spectrometry. In this study, we demonstrated that depth can modify the size, shape and thickness of nacre tablets, but not the d18O. This environmental modification is important for the biomineralization of the shell of the pearl oyster Pinctada margaritifera.

  4. An efficient hybrid conventional method to fabricate nacre-like bulk nano-laminar composites

    International Nuclear Information System (INIS)

    Bulk nano-laminar composites were fabricated by a novel technique called Hot-press Assisted Slip Casting (HASC) which combines hot-pressing and slip-casting to improve alignment and volume fraction of the reinforcement. Alumina flakes were used as filler in an epoxy matrix. Microstructure of composites and alignment of flakes were characterized by Scanning Electron Microscope (SEM). Three point bending test and Vickers hardness test were done for mechanical characterization of composites. Flexural tests on Chevron-notched specimens revealed a high work-of-fracture in the case of the fabricated composites reaching to 254 J/m2. Fracture surface of three point bending samples were examined by SEM. Main fracture mechanism is debonding of flakes from the matrix. With its high volume fraction (60%) of reinforcement phase and high degree of flake alignment, a nacre-like microstructure was achieved with a relatively efficient, cost effective and simple hybrid conventional method.

  5. Bivalve growth rate and isotopic variability across the Barents Sea Polar Front

    Science.gov (United States)

    Carroll, Michael L.; Ambrose, William G.; Locke V, William L.; Ryan, Stuart K.; Johnson, Beverly J.

    2014-02-01

    Analysis of bivalve shell increments provides a means to reconstruct long-term patterns in growth histories and assess factors that regulate marine ecosystems, while tissue stable isotopes are indicators of food sources and trophic dynamics. We examined shell growth patterns and tissue stable isotopic composition (δ13C and δ15N) of the hairy cockle (Ciliatocardium ciliatum) in the northwest Barents Sea to evaluate the influence of different water masses and the Polar Front on growth rates and food sources and to assess the influence of climatic variability on ecological processes over seasonal to decadal scales. Shell growth rates were highest in Atlantic water, intermediate in Arctic water, and lowest at the Polar Front. Temporal patterns of ontogenetically-adjusted growth (SGI) were negatively correlated with the Atlantic Multidecadal Oscillation (AMO), local precipitation and ice-free days. The highest growth occurred during colder periods with more sea ice, while lower growth was associated with warmer periods and less sea ice. Stable isotope values of lipid-extracted tissues from Atlantic water cockles were enriched in δ13C by up to 2.1‰ and δ15N by 1.5‰ compared to animals from Arctic waters. Distinct seasonal and water mass variations in stable isotopic values reflect spatial and temporal variability in food supplies to the bivalves in this region on small spatial scales. Overall, Atlantic waters supported the highest growth rates, the most complex trophic webs, and the greatest sensitivity to interannual variability in environmental conditions. Bivalves from Arctic waters were the most distinct of the three groups in their response to regional climate forcing and local environmental manifestations of those conditions. The Polar Front exhibits growth and isotopic characteristics predominantly of the Atlantic domain. These results demonstrate that integrating results of sclerochronological and stable isotopic analyses of benthic bivalves provide

  6. Marine diatoms sustain growth of bivalves in a Mediterranean lagoon

    Science.gov (United States)

    Pernet, Fabrice; Malet, Nathalie; Pastoureaud, Annie; Vaquer, André; Quéré, Claudie; Dubroca, Laurent

    2012-02-01

    Carbon stable isotopes and fatty acids were measured in the suspended particulate organic matter (POM) of the Thau lagoon to study its qualitative temporal changes in relation to environmental factors and to identify the food sources of bivalves over a one-yr-cycle in relation to their growth. Reciprocally, the impact of shellfish farming on POM was also studied. Oysters and mussels were sampled and measured for biometry, stable isotopes and fatty acid composition. Water samples were collected at two sites, both inside and outside of the shellfish farming area, to determine concentrations in POM, chlorophyll a (Chl a) and stable isotopes. Carbon isotopes and fatty acids in bivalves reflected seasonal changes in food sources, which varied consistently with the environment. Seasonal changes in δ13C and fatty acids in the bivalves suggested that dietary phytoplankton contribution varied according to season. Terrestrial organic matter and bacteria can contribute to the diet of bivalves during non-bloom periods. Mussels seemed to rely more on diatoms and less on terrestrial organic matter and bacteria than oysters did, particularly when phytoplankton biomass was low during the summer. Although one- and two-yr-old oysters showed similar δ13C, their fatty acid dynamics differed slightly. Periods of high growth rate in bivalves were mainly fuelled by diatoms, thus highlighting the importance of seasonal blooms of microphytoplankton during the critical period of bivalve growth and gamete production. Although there was no significant effect of shellfish farms on Chl a and POM δ13C, consistent differences indicate that stable isotopes could be used successfully to investigate the effects of bivalve aquaculture.

  7. Ocular manifestations of leptospirosis

    OpenAIRE

    Rathinam S

    2005-01-01

    Leptospiral uveitis is a common entity in tropical countries. Ocular manifestations are noted in the second phase of illness, but these remain under-diagnosed mainly because of the prolonged symptom-free period that separates the systemic manifestations from detection of ocular manifestations.Varying ophthalmic presentations and the intrinsic nature of different types of uveitis to mimic one another also challenge the accuracy of the diagnosis. Of the individual ocular signs, the combination...

  8. Rheumatic manifestations of scurvy.

    Science.gov (United States)

    Ferrari, Claudia; Possemato, Niccolò; Pipitone, Nicolò; Manger, Bernhard; Salvarani, Carlo

    2015-04-01

    This paper reviews the rheumatological manifestations of scurvy, based on articles published in English from 1965 until October 2014, with a particular focus on rheumatological manifestations. Scurvy is a rare, uncommon disease in developed countries. Due to its clinical heterogeneity, the disease can easily mimic rheumatologic conditions leading to a delay in diagnosis and treatment. PMID:25854491

  9. Fish and bivalves at Bolsa Chica Marsh re-establishment project; Progress report III

    OpenAIRE

    Knaggs, Eric H.; Mall, Rolf E.

    1980-01-01

    The objectives of our fish and bivalve study are: 1. Determine changes in the number of species of fish and bivalves before Phase I and during Phase 1 at Bolsa Chica Marsh. 2. Determine if California Department of Fish and Game's predicted benefits in Phase I were achieved by increases in fish species. 3. Determine influences of water management practices upon fish and bivalve composition. Thirteen species of fish and five species of bivalves were collected from ...

  10. Modeling the carbon isotope composition of bivalve shells (Invited)

    Science.gov (United States)

    Romanek, C.

    2010-12-01

    The stable carbon isotope composition of bivalve shells is a valuable archive of paleobiological and paleoenvironmental information. Previous work has shown that the carbon isotope composition of the shell is related to the carbon isotope composition of dissolved inorganic carbon (DIC) in the ambient water in which a bivalve lives, as well as metabolic carbon derived from bivalve respiration. The contribution of metabolic carbon varies among organisms, but it is generally thought to be relatively low (e.g., 90%) in the shells from terrestrial organisms. Because metabolic carbon contains significantly more C-12 than DIC, negative excursions from the expected environmental (DIC) signal are interpreted to reflect an increased contribution of metabolic carbon in the shell. This observation contrasts sharply with modeled carbon isotope compositions for shell layers deposited from the inner extrapallial fluid (EPF). Previous studies have shown that growth lines within the inner shell layer of bivalves are produced during periods of anaerobiosis when acidic metabolic byproducts (e.g., succinic acid) are neutralized (or buffered) by shell dissolution. This requires the pH of EPF to decrease below ambient levels (~7.5) until a state of undersaturation is achieved that promotes shell dissolution. This condition may occur when aquatic bivalves are subjected to external stressors originating from ecological (predation) or environmental (exposure to atm; low dissolved oxygen; contaminant release) pressures; normal physiological processes will restore the pH of EPF when the pressure is removed. As a consequence of this process, a temporal window should also exist in EPF at relatively low pH where shell carbonate is deposited at a reduced saturation state and precipitation rate. For example, EPF chemistry should remain slightly supersaturated with respect to aragonite given a drop of one pH unit (6.5), but under closed conditions, equilibrium carbon isotope fractionation

  11. Artificially evolved functional shell morphology of burrowing bivalves

    DEFF Research Database (Denmark)

    Germann, D. P.; Schatz, W.; Hotz, Peter Eggenberger

    2014-01-01

    dimensional (3D) objects, the first ever artificial evolution of a physical bivalve shell was performed. The result was a vertically flattened shell occupying only the top sediment layers. Insufficient control of the sediment was the major limitation of the setup and restricted the significance of the results......, there are almost no studies experimentally testing their dynamic properties. To investigate the functional morphology of the bivalve shell, we employed a synthetic methodology and built an experimental setup to simulate the burrowing process. Using an evolutionary algorithm and a printer that prints three...

  12. Effect of water soluble extract of nacre (Pinctada maxima) on alkaline phosphatase activity and Bcl-2 expression in primary cultured osteoblasts from neonatal rat calvaria.

    Science.gov (United States)

    Moutahir-Belqasmi, F; Balmain, N; Lieberrher, M; Borzeix, S; Berland, S; Barthelemy, M; Peduzzi, J; Milet, C; Lopez, E

    2001-01-01

    The nacre (mother of pearl) layer of the oyster Pinctada maxima shell can initiate bone formation by human osteoblasts in vivo and in vitro and is a new biomaterial that induces osteogenesis. This activity of nacre could be due to its water-soluble matrix. We examined the action of a water-soluble extract of nacre on the osteoblast phenotype of cells isolated from rat neonatal calvaria by measuring alkaline phosphatase (ALP) activity and by localization of the anti-apoptotic protein Bcl-2 by immunocytochemistry. ALP activity was increased 7% (pproduction in osteoblasts, that is correlated with the cell cycle. Bcl-2 was also abundant in the nucleoli of extract-treated cells. Thus, the concentration and subcellular distribution of Bcl-2 in osteoblasts in primary cultures is influenced by nacre extract, and related to the cell cycle and the regulation of gene expression. Hence, knowledge of how water-soluble extracts of Pinctada maxima nacre act on osteoblasts in vitro may reveal the mechanisms involved in its action in vivo on bone cells and bone regeneration. PMID:15348370

  13. Pulmonary manifestations of malaria

    International Nuclear Information System (INIS)

    We report on the two different types of pulmonary manifestations in acute plasmodium falciparum malaria. The more severe variant shows long standing interstitial pulmonary infiltrates, whereas in the more benign courses only short-term pulmonary edemas are visible. (orig.)

  14. Pulmonary manifestations of malaria

    Energy Technology Data Exchange (ETDEWEB)

    Rauber, K.; Enkerlin, H.L.; Riemann, H.; Schoeppe, W.

    1987-05-01

    We report on the two different types of pulmonary manifestations in acute plasmodium falciparum malaria. The more severe variant shows long standing interstitial pulmonary infiltrates, whereas in the more benign courses only short-term pulmonary edemas are visible.

  15. Lower Carboniferous marine bivalves from the Cantabrian Mountains (Spain)

    NARCIS (Netherlands)

    Amler, M.R.W.; Winkler Prins, C.F.

    1999-01-01

    The Lower Carboniferous bivalves of the Vegamián and Genicera formations are described, followed by a brief discussion on palaeoenvironmental and palaeogeographical aspects. The black shales of the Vegamián Fm. (Tournaisian) yield a peculiar association of euchondriid taxa (Euchondria wagneri sp. no

  16. A Bivalve Proxy for Neogene Antarctic Shelf Marine Environments

    Science.gov (United States)

    Clark, N. A.; Williams, M.; Quilty, P. G.; Leng, M. J.; Zalasiewicz, J. A.; Smellie, J.; Dowsett, H. J.

    2012-12-01

    The Neogene shallow-marine successions of the Antarctic Peninsula and of the East Antarctic region preserve rich assemblages of bivalve molluscs. These bivalve molluscs provide a detailed record of palaeoseasonality in the chemical signature and morphology of their shells that can be used to assess sea temperatures and sea ice extent for the Antarctic shelf during the Pliocene. Analyses identify the following. 1) Neogene bivalves from James Ross Island, Antarctic Peninsula, comprise material of late Miocene through to late Pliocene age. Results identify warm (ca. 3-10 °C) early Pliocene sea temperatures, and cooler late Pliocene sea temperatures (ca. 0-4 °C), and flag a cooling trend which is consistent with the evolution of polar climate through this interval. 2) Neogene bivalves from the Larsemann Hills, East Antarctic, identify generally warmer than present sea temperatures (ca. 0-11 °C) in the early Pliocene consistent with data from other fossil groups of this age, including dolphins and silicoflagellates. The new data may provide significant ground truth for climate models assessing the Southern Ocean and Antarctic shelf climate.

  17. Molecular approaches to bivalve population studies: a review

    Directory of Open Access Journals (Sweden)

    Dragomir-Cosmin David

    2011-12-01

    Full Text Available This paper presents a literature review concerning the importance of molecular approaches in bivalve’s population study. The class Bivalvia counts more than 20,000 species with a wide distribution both in freshwater and marine environment. Given their importance especially in aquaculture as a source of food, they have also a strong economic impact upon human society. This review encompasses best practices in bivalve studies from field sampling to laboratory analyses, addressing questions about molecular methods and tools commonly used by specialized researchers. Molecular tools specifically deals with phylogeography, population genetics, biology, ecology and taxonomy. In all these fields, molecular markers play an important role by completing some unanswered questions such as the role of the bivalves in the ecosystems in relation to anthropogenic and global change issues. Numerous genetic markers were developed for specific problems, thereferore we identify as a major issue the absence of uniform and universally recognized methods. The various sections of the paper emphasize from peer reviewed literature literature which are considered the most useful markers, costs and benefits of different methodology, major gaps of knowledge.in bivalve population studies. By reviewing virtually all genetic markers employed during nearly half a century of bivalve molecular research, in our opinion two are the best option “tools: the mitochondrial COI (cytochrome oxidase subunit I and nuclear ITS2 (internal transcribed spacer 2.

  18. Study of the effects of gamma sterilization on a bio material potential bone substitute: the nacre of Pinctada radiata (Leach, 1814)

    International Nuclear Information System (INIS)

    In this work, we studied the effects of gamma irradiation at a dose of 25 kGy on physico-chemical properties of the nacre of the pearl oyster P. radiata Tunisian coast. The aim of our work is, after sterilizing the shell to gamma radiation, the study of its crystal structure, behavior and thermodynamics of the qualitative and quantitative composition of organic and inorganic matrices and compare them with those of the non-irradiated pearl . In addition, there has been interest in developing the method of sterilization with gamma irradiation to 25 kGy of the nacre of the pearl oyster Pinctada radiata.

  19. Dengue fever: atypical manifestation

    Directory of Open Access Journals (Sweden)

    Nataraj Gangasiddaiah

    2014-08-01

    Full Text Available Dengue fever is affecting millions of population globally. For the past one decade, we have seen several outbreaks and even causing significant mortality of affected population. We witnessed numerous pattern and multisystem presentation of dengue in this period. The CNS manifestation like encephalitis, polyneuropathy (GB like syndrome and paresthesias were uncommonly reported priorly. Pancreatitis, polyserositis, carditis of varying severity and hepatic failure are the, some of atypical manifestations observed in recent out breaks. So dengue illness can presents with multi system involvement and can account to significant mortality. Here an attempt was done to present varying, uncommon and atypical manifestation of dengue illness. [Int J Res Med Sci 2014; 2(4.000: 1804-1806

  20. [Unusual Migraine Manifestations].

    Science.gov (United States)

    Schipper, Sivan; Gantenbein, Andreas R; Sandor, Peter S

    2016-06-01

    Migraine is a complex neurologic disorder by which several systems of the central nervous system (autonomous system, affective, cognitive, sensoric and motoric system) may be affected on different levels. Around a fourth of the patients have migraine aura. The most common aura is the visual aura, followed by sensoric aura. But motoric deficits as well as deficits of higher cortical centers (disorders of thinking, orientation, coherence or concentration) may occur as well. In analogy with a headache calendar, an aura calendar can deliver important help in the diagnostic process of rare migraine manifestations and prevent underdiagnosis of unusual migraine manifestations. Complex migraine manifestations are diagnoses of exlusion, and a broad diagnostic work-up is warranted in order to exclude dangerous neurologic pathologies. There are no specific therapeutic recommendations, as there is a lack of randomized controlled studies. PMID:27269777

  1. Pulmonary manifestations of leptospirosis

    Directory of Open Access Journals (Sweden)

    Sameer Gulati

    2012-01-01

    Full Text Available Leptospirosis has a spectrum of presentation which ranges from mild disease to a severe form comprising of jaundice and renal failure. Involvement of the lung can vary from subtle clinical features to deadly pulmonary hemorrhage and acute respiratory distress syndrome. Of late, it has been identified that leptospirosis can present atypically with predominant pulmonary manifestations. This can delay diagnosis making and hence optimum treatment. The purpose of this review is to bring together all the reported pulmonary manifestations of leptospirosis and the recent trends in the management.

  2. Synergistic toughening of hard, nacre-mimetic MoSi2 coatings by self-assembled hierarchical structure

    OpenAIRE

    Jiang Xu; Xiaoli Zhao; Paul Munroe; Zonghan Xie

    2014-01-01

    Like many other intermetallic materials, MoSi2 coatings are typically hard, but prone to catastrophic failure due to their low toughness at ambient temperature. In this paper, a self-assembled hierarchical structure that closely resembles that of nacre (i.e., mother of pearl) was developed in a MoSi2-based coating through a simple, yet cost-effective, depostion technique. The newly formed coating is tough and can withstand multiple indentations at high loads. Key design features responsible f...

  3. Cardiovascular manifestations in hyperthyroidism

    OpenAIRE

    Vairamani Kandan; Sathyamurthy P; Rajkumar M; Lavanya Narayanan

    2016-01-01

    Background: It is well known that thyroid hormone directly affects the heart and peripheral vascular system. In hyperthyroidism, cardiovascular manifestations are frequent findings. Atrial arrhythmias, limitations in exercise tolerance, and congestive heart failure were reported to occur more common in older patients as a result of hyperthyroidism. Cardiovascular signs of hyperthyroidism include tachycardia, widened pulse pressure, marked increase in cardiac output with impaired cardiovascula...

  4. Manifestly Covariant Relativity

    OpenAIRE

    Dalton, Kenneth

    2006-01-01

    According to Einstein's principle of general covariance, all laws of nature are to be expressed by manifestly covariant equations. In recent work, the covariant law of energy-momentum conservation has been established. Here, we show that this law gives rise to a fully covariant theory of gravitation and that Einstein's field equations yield total energy-momentum conservation.

  5. Unique morphology and gradient arrangement of nacre's platelets in green mussel shells

    International Nuclear Information System (INIS)

    Nacre has long served as a classic model in biomineralization and the synthesis of biomimetic materials. However, the morphology and arrangement of its basic building blocks, the aragonite platelets, are still under hot debate. In this study, using a field emission scanning electron microscope (SEM), a high-resolution transmission electron microscope (HRTEM), and an X-ray diffractometer (XRD), we investigate the platelets at the edges and centers of green mussel shells. We find that 1) flat and curved platelets coexist in green mussel shells; 2) the immature platelets at the shell edge are aggregates of aragonite nanoparticles, whereas the immature ones at the shell center are single crystals; and 3) the morphology and thickness of the platelets exhibit a gradient arrangement. Based on these findings, we hypothesize that the gradient in the thickness and curvature of the platelets may probably result from the difference in growth rate between the edge and the center of the shell and from the gradient in compressive stress imposed by the closing of the shells by the adductor muscles or the withdrawal of the periostracum by the mantle. We expect that the presented results will shed new light on the formation mechanisms of natural composite materials. - Highlights: • Flat and curved platelets coexist in green mussel shells. • The immature platelets at the shell edge consist of aragonite nanoparticles. • The immature platelets at the shell center are single crystals. • The morphology and thickness of platelets exhibit a gradient arrangement. • The gradient arrangement of platelets may result from the stress gradient

  6. Unique morphology and gradient arrangement of nacre's platelets in green mussel shells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jun; Zhang, Gangsheng, E-mail: zhanggs@gxu.edu.cn

    2015-07-01

    Nacre has long served as a classic model in biomineralization and the synthesis of biomimetic materials. However, the morphology and arrangement of its basic building blocks, the aragonite platelets, are still under hot debate. In this study, using a field emission scanning electron microscope (SEM), a high-resolution transmission electron microscope (HRTEM), and an X-ray diffractometer (XRD), we investigate the platelets at the edges and centers of green mussel shells. We find that 1) flat and curved platelets coexist in green mussel shells; 2) the immature platelets at the shell edge are aggregates of aragonite nanoparticles, whereas the immature ones at the shell center are single crystals; and 3) the morphology and thickness of the platelets exhibit a gradient arrangement. Based on these findings, we hypothesize that the gradient in the thickness and curvature of the platelets may probably result from the difference in growth rate between the edge and the center of the shell and from the gradient in compressive stress imposed by the closing of the shells by the adductor muscles or the withdrawal of the periostracum by the mantle. We expect that the presented results will shed new light on the formation mechanisms of natural composite materials. - Highlights: • Flat and curved platelets coexist in green mussel shells. • The immature platelets at the shell edge consist of aragonite nanoparticles. • The immature platelets at the shell center are single crystals. • The morphology and thickness of platelets exhibit a gradient arrangement. • The gradient arrangement of platelets may result from the stress gradient.

  7. The Bivalve Yangtzedonta is not the Brachiopod Xianfengella

    Institute of Scientific and Technical Information of China (English)

    YU Wen

    2005-01-01

    The alleged "holotype" of the bivalve Yangtzedontaprimitiva Yu, 1985 figured by Qian (2001) is a broken and distorted specimen of the brachiopod Xianfengella prima He and Yang, 1982 and not the holotype of Y. primitiva. Qian contends that the oldest recognized monoplacophoran, Maikhanella pristinis (Jiang, 1980), is neither a monoplacophoran nor the oldest molluscan fossil in the Meishucunian Stage of China. Furthermore, he considers that the oldest bivalve Xianfengoconcha elliptica Zhang, 1980 is an inarticulate brachiopod, not a mollusc. Watsonella yunnanensis (He and Yang, 1982), is associated with Yangtzedonta primitiva Yu but indicates no evolutionary relationship between the Classes Rostroconchia and Bivalvia in the Lower Cambrian Zhongyicun Member of the Yuhucun Formation. Qian's confusion in using non-molluscan fossils to discuss the early evolution of shelled molluscs also confuses the basic concepts of the respective groups.

  8. Comparative pathology in bivalves: Aetiological agents and disease processes.

    Science.gov (United States)

    Carella, F; Feist, S W; Bignell, J P; De Vico, G

    2015-10-01

    Comparative pathology as a scientific discipline studies animal diseases in relation to their aetiology, pathogenesis and prognosis. Among the main aspects of this discipline, regressive changes, host defense responses with pathological implications and progressive changes, represent the majority of the possible responses of cells and tissues to pathogens and exposure to chemicals. One of the most persistent issues in the field of invertebrate pathology is the variability in terminology and definition, which has led to confusion in scientific communication. The aim of this paper is to provide an overview of the pathological basis of bivalve disease (defensive, regressive and progressive phenomena) and contribute to the standardised terminology for bivalve molluscan disease in the context of comparative pathology. PMID:26215472

  9. Indian marine bivalves: Potential source of antiviral drugs

    Digital Repository Service at National Institute of Oceanography (India)

    Chatterji, A.; Ansari, Z.A.; Ingole, B.S.; Bichurina, M.A.; Sovetova, M.; Boikov, Y.A.

    ( Crassostrea gryphoides ) and clam (Meretrix casta , M. meretrix , Paphia malabarica , Villorita cypr i noides ) . Recent investigations conducted jointly by Russian and Indian scientists showed that Indian green mussels ( P. viridis... prophyla c tic effect has been observed in mice when a dose of mussel extract was given 5 h before inoculation of v i rus 3 and the mice showed 100% survival. Marine bivalves are filter - feeding animals, and while feeding they accumulate...

  10. Light indirectly mediates bivalve habitat modification and impacts on seagrass

    DEFF Research Database (Denmark)

    Castorani, Max Christopher Nicholas; Glud, Ronnie N.; Hasler-Sheetal, Harald;

    2015-01-01

    by directly or indirectly influencing the effects of habitat-modifying organisms that are capable of simultaneously ameliorating and exacerbating multiple stressors. Itwas hypothesized that light availability changes seagrassmetabolismand thereby indirectly regulates bivalve habitat modification...... and respiration),mussels and lowlight availability exacerbated sulfide intrusion of eelgrass tissues. Surprisingly, sulfide stress did not affect plant growth, survival, or energy stores. Thus, habitat modification by musselsmay represent a risk to eelgrass, especially during low productivity conditions...

  11. Magnetosome-containing bacteria living as symbionts of bivalves

    OpenAIRE

    Dufour, Suzanne C.; Laurich, Jason R; Batstone, Rebecca T; McCuaig, Bonita; Elliott, Alexander, 1983-; Poduska, Kristin M

    2014-01-01

    Bacteria containing magnetosomes (protein-bound nanoparticles of magnetite or greigite) are common to many sedimentary habitats, but have never been found before to live within another organism. Here, we show that octahedral inclusions in the extracellular symbionts of the marine bivalve Thyasira cf. gouldi contain iron, can exhibit magnetic contrast and are most likely magnetosomes. Based on 16S rRNA sequence analysis, T. cf. gouldi symbionts group with symbiotic and free-living sulfur-oxidi...

  12. Comparative analysis of the transcriptome in tissues secreting purple and white nacre in the pearl mussel Hyriopsis cumingii.

    Directory of Open Access Journals (Sweden)

    Zhiyi Bai

    Full Text Available The triangle sail mussel Hyriopsis cumingii (Lea is the most important mussel species used for commercial freshwater pearl production in China. Mussel color is an important indicator of pearl quality. To identify genes involved in the nacre coloring, we conducted RNA-seq and obtained 541,268 sequences (298 bp average size and 440,034 sequences (293 bp average size in secreting purple and white nacre libraries (P- and W-libraries, respectively. The 981,302 Expressed Sequence Tags (ESTs were assembled into 47,812 contigs and 289,386 singletons. In BLASTP searches of the deduced protein, 22,495 were proteins with functional annotations. Thirty-three genes involved in pearl or shell formation were identified. Digital expression analysis identified a total of 358 differentially expressed genes, and 137 genes in the P-library and 221 genes in the W-library showed significantly higher expression. Furthermore, a set of SSR motifs and SNPs between the two samples was identified from the ESTs, which provided the markers for genetic linkage, QTL analysis and future breeding. These EST sequences provided valuable information to further understand the molecular mechanisms involved in the formation, color determination and evolution of the pearl or shell.

  13. Orofacial manifestations of achondroplasia

    Science.gov (United States)

    Rohilla, Smriti; Kaushik, Atul; Vinod, V.C.; Tanwar, Renu; Kumar, Munish

    2012-01-01

    Achondroplasia (Online Mendelian Inheritance in Man [OMIM] 100800), is considered as a form of skeletal dysplasia dwarfism that manifests with stunted stature and disproportionate limb shortening. Achondroplasia is of special interest in the field of dentistry because of its characteristic craniofacial features which include relative macrocephaly, depressed nasal bridge and maxillary hypoplasia. Presence of large head, implanted shunt, airway obstruction and difficulty in head control requires special precautions during dental management. The current case report highlights the orofacial manifestations of Achondroplasia in a young pediatric patient, along with the multidisciplinary treatment (including the dental treatment) done for the patient which also might help the general practitioners in better understanding of the condition. PMID:27298609

  14. Cutaneous manifestations in Brucellosis

    OpenAIRE

    Zeynep Karaali; Birol Baysal; Sule Poturoglu; Mehmet Kendir

    2011-01-01

    Brucellosis is a common worldwide zoonotic disease. Cutaneous manifestations are not specific and affect 1–14% of patients with brucellosis. Here, we describe 49-year-old female with fever and a diffuse maculopapular rash due to Brucella melitensis infection. Histopathology of skin biopsy revealed leukocytoclastic vasculitis; positive blood cultures for B. melitensis established the diagnosis of brucellosis. We provide a review of the relevant literature.

  15. Pulmonary manifestations of leptospirosis

    OpenAIRE

    Sameer Gulati; Anu Gulati

    2012-01-01

    Leptospirosis has a spectrum of presentation which ranges from mild disease to a severe form comprising of jaundice and renal failure. Involvement of the lung can vary from subtle clinical features to deadly pulmonary hemorrhage and acute respiratory distress syndrome. Of late, it has been identified that leptospirosis can present atypically with predominant pulmonary manifestations. This can delay diagnosis making and hence optimum treatment. The purpose of this review is to bring together a...

  16. MANIFEST OF DEPTH SOCIOPSYCHOLOGY

    OpenAIRE

    ZELITCHENKO ALEXANDER

    2013-01-01

    The observations of motives of activity of big groups (nations, confessions etc.) as a whole result in discovery of the part of unconscious mind that is common for all members of big group a collective unconscious. Two parts of collective unconscious may be determined: the collective superconscious known first as a group archetype and the collective subconscious, which manifest itself for example in phenomenon of collective trauma. Depth sociopsychology is a science about the collective uncon...

  17. Orofacial manifestations of achondroplasia

    OpenAIRE

    Kaushik, Atul; Kumar, Munish; Rohilla, Smriti; Tanwar, Renu; Vinod, V.C.

    2012-01-01

    Achondroplasia (Online Mendelian Inheritance in Man [OMIM] 100800), is considered as a form of skeletal dysplasia dwarfism that manifests with stunted stature and disproportionate limb shortening. Achondroplasia is of special interest in the field of dentistry because of its characteristic craniofacial features which include relative macrocephaly, depressed nasal bridge and maxillary hypoplasia. Presence of large head, implanted shunt, airway obstruction and difficulty in head control r...

  18. Predation and habitat modification synergistically interact to control bivalve recruitment on intertidal mudflats

    OpenAIRE

    Van der Heide, Tjisse; Tielens, Elske; van der Zee, Els; Weerman, Ellen J.; Holthuijsen, Sander; Eriksson, Britas Klemens; Piersma, Theun; van de Koppel, Johan; Olff, Han

    2014-01-01

    Bivalves are key components of coastal ecosystems because they link pelagic and benthic food webs, and shape the landscape through habitat modification. Nevertheless, many bivalve stocks have dramatically declined, and recruitment failure due to (anthropogenically-) increased predation by mesopredators and loss of facilitation mechanisms have been separately hypothesized as underlying causes. Here, we tested the interactive effects of predation and habitat modification on bivalve recruitment ...

  19. Ocular manifestations of leptospirosis

    Directory of Open Access Journals (Sweden)

    Rathinam S

    2005-01-01

    Full Text Available Leptospiral uveitis is a common entity in tropical countries. Ocular manifestations are noted in the second phase of illness, but these remain under-diagnosed mainly because of the prolonged symptom-free period that separates the systemic manifestations from detection of ocular manifestations.Varying ophthalmic presentations and the intrinsic nature of different types of uveitis to mimic one another also challenge the accuracy of the diagnosis. Of the individual ocular signs, the combination of acute, non-granulomatous, panuveitis, hypopyon, vasculitis, optic disc edema, membranous vitreous opacities and absence of choroiditis or retinitis have high predictive value for the clinical diagnosis of leptospiral uveitis. Geographic location of the patient, occupation, socio-economic status, risk factors related to exposure, past history of fever or jaundice also aid in diagnosis.Steroids are the mainstay of treatment for leptospiral uveitis. Depending upon the severity and anatomical location of inflammatory lesion, topical, peri-ocular and/or systemic steroids are given. The prognosis is generally good, even when the inflammation is severe.

  20. Neurological manifestations of malaria

    Directory of Open Access Journals (Sweden)

    Gustavo C. Román

    1992-03-01

    Full Text Available The involvement of the nervous system in malaria is reviewed in this paper. Cerebral malaria, the acute encephalopathy which complicates exclusively the infection by Plasmodium falciparum commonly affects children and adolescents in hyperendemic areas. Plugging of cerebral capillaries and venules by clumped, parasitized red cells causing sludging in the capillary circulation is one hypothesis to explain its pathogenesis. The other is a humoral hypothesis which proposes nonspecific, immune-mediated, inflammatory responses with release of vasoactive substances capable of producing endothelial damage and alterations of permeability. Cerebral malaria has a mortality rate up to 50%, and also a considerable longterm morbidity, particularly in children. Hypoglycemia, largely in patients treated with quinine, may complicate the cerebral symptomatology. Other central nervous manifestations of malaria include intracranial hemorrhage, cerebral arterial occlusion, and transient extrapyramidal and neuropsychiiatric manifestations. A self-limiting, isolated cerebellar ataxia, presumably caused by immunological mechanisms, in patients recovering from falciparum malaria has been recognized in Sri Lanka. Malaria is a common cause of febrile seizures in the tropics, and it also contributes to the development of epilepsy in later life. Several reports of spinal cord and peripheral nerve involvement are also available. A transient muscle paralysis resembling periodic paralysis during febrile episodes of malaria has been described in some patients. The pathogenesis of these neurological manifestations remains unexplored, but offers excellent perspectives for research at a clinical as well as experimental level.

  1. Relating Productivity Events to Holocene Bivalve Shell Growth Rates

    Science.gov (United States)

    Huntley, J. W.; Krause, R. A.; Kowalewski, M.; Romanek, C. S.; Kaufman, D. S.; Simoes, M. G.

    2007-12-01

    The growth rate of a bivalve can be influenced by many environmental factors that can change during the life of the organism. In this contribution we present initial data from a millennium scale chronology to assess the relationship between ontogenetic growth in the bivalve Semele casali and paleoenvironmental conditions preserved in the shell using growth increment analysis, radiocarbon-calibrated amino acid racemization dating techniques, stable isotopes (C and O) and high spatial resolution (125-150 samples per cm of shell profile) trace element (Ba, Mn) analysis (LA-ICPMS). Time-averaged specimens of S. casali were dredged from two sites at 10 meters and 30 meters depth along the inner continental shelf at Ubatuba Bay in the Southeast Brazilian Bight, an area influenced by productivity pulses triggered by coastal runoff events and coastal upwelling. Seventy-five individual valves were dated using amino acid racemization (aspartic acid). Dates were calculated using an expanded version of a previously published relationship (Barbour Wood et al., 2006 Quaternary Research 323- 331) between aspartic acid ratios and AMS radiocarbon dates of twelve S. casali individuals from the same sampling locations. The resulting time series has complete coverage for the past three thousand years at centennial resolution. From this time series, a sub-sample of dated valves was selected for more detailed growth increment, stable isotope and high-resolution trace element (Ba/Ca and Mn/Ca) analyses. Oceanic productivity is expressed differentially in the trace element profiles of S. casali with elevated Ba/Ca and Mn/Ca ratios capturing nutrient input through coastal runoff events while elevated Ba/Ca and depressed Mn/Ca ratios represent input through coastal upwelling. Fluctuations in Ba/Ca and Mn/Ca are not correlated to fluctuations in relative growth throughout the ontogeny of an individual bivalve, nor are they expected to be as periods of increased productivity are transient

  2. Manifeste des digital humanities

    OpenAIRE

    2012-01-01

    Introduction au manifeste L’utilisation de l’informatique en sciences humaines et sociales est pratiquée depuis maintenant plus de quarante ans. Plusieurs voies ont été explorées au cours de cette déjà assez longue histoire. La plus récente, qui prend le nom de digital humanities, désigne une intégration intense et à plu­sieurs niveaux des technologies numériques dans tous les processus de recherche, depuis la collecte de données jusqu’à la publication. Dans ce nouveau contexte d’un travail n...

  3. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... Conference Session Videos Research Teleconference Presentations Clinical Manifestations Diagnostic Criteria TSC Consensus Recommendations Publications Clinical Trials Tissue ...

  4. Radiological manifestations of melioidosis

    International Nuclear Information System (INIS)

    Melioidosis is a serious infection that is associated with high mortality. It is due to a Gram-negative bacterium, Burkholderia pseudomallei which is an environmental saprophyte found in wet soils. Melioidosis is endemic to northern Australia and the Southeast Asia. However, there is now increasing number of reports of imported cases to regions where this infection has not been previously encountered. Almost any organ can be affected. Like many other conditions, radiological imaging is an integral part of the diagnostic workup of melioidosis. Awareness of the various radiological manifestations can help direct appropriate investigations to achieve early diagnosis and the initiation of appropriate treatment. Generally, there are no known characteristic features on imaging that can specifically differentiate melioidosis from other infections. However, the 'honeycomb' appearance has been described to be characteristic for large melioidosis liver abscesses. Simultaneous involvement of various organs is also characteristics. To date, there are few data available on the radiological manifestations of melioidosis. The present pictorial essay describes melioidosis affecting the various organs.

  5. [Central manifestations of dystrophinopathies].

    Science.gov (United States)

    Cuisset, J-M; Rivier, F

    2015-12-01

    The dystrophin gene involved in Duchenne and Becker muscular dystrophy is expressed in three main tissues resulting in clinical manifestations: skeletal muscle, heart and central nervous system. The 6 different existing dystrophins in the brain may play a role in the maturation and plasticity of neuronal synapses in particular by their functions in clustering and stabilization of different receptors at the post synaptic membrane. The possibility of an intellectual deficiency in Duchenne muscular dystrophy is known from the original description by Duchenne himself. Current data are in line with a constant cognitive impairment with a Gaussian curve shifted intellectual quotient (IQ) at -1 standard deviation from the standard population with an average IQ around 80. Clinical manifestations suggestive of a central nervous system involvement can affect all dystrophinopathies, including isolated central presentations without myopathic sign. The phenotypic spectrum appears broader and more subtle than non specific intellectual deficiency. The isolated or shared involvement of specific cognitive functions is possible (memory functions, executive functions, attention) with or without intellectual deficiency. Autism spectrum disorders are also among the encountered events. In clinical practice, it seems worth to ask for a measurement of serum creatine kinase (CK) in these different situations, keeping in mind that pure forms of central dystrophinopathies with a normal CK level have been recently reported. PMID:26773588

  6. Sinonasal Manifestations in Cystic Fibrosis

    OpenAIRE

    Oomen, Karin P. Q.; Max M. April

    2012-01-01

    Cystic fibrosis is a genetic disease, characterized by accumulation of thickened mucous secretions in exocrine glands. Although the major clinical manifestations of the disease are pancreatic and pulmonary disease, the majority of cystic fibrosis patients will develop sinonasal manifestations as well. This paper outlines the etiology, evaluation, and management of the nasal and sinus manifestations in patients with cystic fibrosis.

  7. 珍珠层有机质及其矿化响应研究%Organic matter in nacre and its mineralization effect

    Institute of Scientific and Technical Information of China (English)

    张恩; 胡林玉; 黄福泉; 彭明生

    2013-01-01

    Although its concentration is extremely low (about 5% of the volume of nacre) and its research technique is limited, the organic matrix in nacre not only is the most fundamental difference between biominerals and natural inorganic minerals but also has an important effect on biomineralization. In this study, the nacres of pearls and shells cultured in freshwaters and seawaters in Guangxi, Guangdong, Zhejiang and Jiangsu and those in corals were tested by Hitachi 835-50 High speed Amino Acid Analyzer and, as a result, the sorts and content of amino acids of organic matrix in nacre specimens were acquired. In combination with the microtopograpgy of nacre's organics investigated by SEM and HRTEM, the correlation analysis and cluster analysis produced some special amino acid constitutions or categories, which correspond to different organic macromolecules in different spatial positions, structures, kinds, shapes or sizes of nacres. These analyses show that the mineralization effect of organic matrix in nacre is characterized by diversity and complexity, which results in the diversity and complexity of inorganic minerals in species, size, evolution. Hence the unique microstructure of nacre can be formed by inducing and controlling. The conclusion obtained by the authors is significant for understanding the effect of organic matrix on biomineralization in nacre.%珍珠层中的有机质极其重要,它不仅是生物矿物与纯无机矿物的根本区别,而且具有重要的生物矿化响应效应.但珍珠层中有机质含量极低,约为珍珠层体积的5%,致使研究手段受到了很大限制.选择广西、广东、浙江、江苏等地的海水养殖珍珠、淡水养殖珍珠、育珠贝贝壳中的珍珠层以及现代珊瑚、珊瑚化石作为研究对象,通过日立835-50型高速氨基酸分析仪获得了各样品氨基酸的种类和含量,继而进行相关性分析和聚类分析,得到一些具有特点的氨基酸组合或类,结合对珍珠

  8. Filtration in some tropical intertidal bivalves exposed to mercury and cadmium mixtures

    OpenAIRE

    Mohan, C.V.; N. R. Menon; Gupta, T.R.C.

    1986-01-01

    Three species of intertidal filter feeding bivalves (Modiolus carvalhoi, Modiolus sp. and Donax spiculum) exposed to mercury and cadmium filtered significantly less volume of water under individual metal and metal mixture stress. Mercury and cadmium in mixtures interacted additively and more than additively (Synergism) in depressing the filtration rate of the bivalves.

  9. Lower Oligocene bivalves of Ramanian Stage from Kachchh, Gujarat, India

    Science.gov (United States)

    Kachhara, R. P.; Jodhawat, R. L.; Devi, K. Bigyapati

    2012-04-01

    Marine Oligocene sequences in India outcrop only in western part of Kachchh. Earlier researchers have recognized the Oligocene strata under the Nari Series (Nagappa 1959; Chatterji and Mathur 1966). The Nari Series has a type area in Pakistan. It has two subdivisions - the Lower Nari (Lower Oligocene) and the Upper Nari (Upper Oligocene). It seems that there is no valid proof about the age of the Lower Nari due to lack of proper fauna (Eames 1975), and according to Pascoe (1962), the Upper Nari slightly transgress into Aquitanian (Lower Miocene), therefore, one has to be very cautious. Biswas and Raju (1971) reclassified the Oligocene strata of Kachchh and lithostratigraphically clubbed them as the Maniyara Fort Formation with type section along the Bermoti stream. This Formation has four members. The lower three members correspond to the Ramanian Stage (Lower Oligocene, Biswas 1971, 1973) while the uppermost to the Waiorian Stage (Upper Oligocene, Biswas 1965, 1971, 1973). The Ramanian Stage is characterized by large forams especially Nummulites fichteli, Nummulites fichteli intermedius, Lepidocyclina ( Eulepidina) dialata and Operculina sp. Several ostracods are also known to occur. Megafauna include bivalves, gastropods, echinoids, corals, mammals and reptiles. Concerning bivalves earlier researchers have recorded a few taxa namely Trisidos semitorta (Lamarck), Cubitostrea angulata (J de C Sowerby), Pecten ( Amussiopecten) labadyei d'Archiac and Haime, Periglypta puerpera (Linne') var. aglaurae Brongniart, Ostrea fraasi Mayer Eymer and listed Pecten laevicostatus J de C Sowerby, Callista pseudoumbonella Vredenburg and Clementia papyracea (Gray) from Kachchh as against overall 42 forms from the Nari Series as a whole (Vredenburg 1928). This tempted us to make an attempt to collect bivalve fauna systematically which are occurring prolifically in the Ramanian Stage. In the present work, for this purpose, sections are worked out around Lakhpat (23°50'N; 68°47'E

  10. Lower Oligocene bivalves of Ramanian Stage from Kachchh, Gujarat, India

    Indian Academy of Sciences (India)

    R P Kachhara; R L Jodhawat; K Bigyapati Devi

    2012-04-01

    Marine Oligocene sequences in India outcrop only in western part of Kachchh. Earlier researchers have recognized the Oligocene strata under the Nari Series (Nagappa 1959; Chatterji and Mathur 1966). The Nari Series has a type area in Pakistan. It has two subdivisions – the Lower Nari (Lower Oligocene) and the Upper Nari (Upper Oligocene). It seems that there is no valid proof about the age of the Lower Nari due to lack of proper fauna (Eames 1975), and according to Pascoe (1962), the Upper Nari slightly transgress into Aquitanian (Lower Miocene), therefore, one has to be very cautious. Biswas and Raju (1971) reclassified the Oligocene strata of Kachchh and lithostratigraphically clubbed them as the Maniyara Fort Formation with type section along the Bermoti stream. This Formation has four members. The lower three members correspond to the Ramanian Stage (Lower Oligocene, Biswas 1971, 1973) while the uppermost to the Waiorian Stage (Upper Oligocene, Biswas 1965, 1971, 1973). The Ramanian Stage is characterized by large forams especially Nummulites fichteli, Nummulites fichteli intermedius, Lepidocyclina (Eulepidina) dialata and Operculina sp. Several ostracods are also known to occur. Megafauna include bivalves, gastropods, echinoids, corals, mammals and reptiles. Concerning bivalves earlier researchers have recorded a few taxa namely Trisidos semitorta (Lamarck), Cubitostrea angulata (J de C Sowerby), Pecten (Amussiopecten) labadyei d’Archiac and Haime, Periglypta puerpera (Linne’) var. aglaurae Brongniart, Ostrea fraasi Mayer Eymer and listed Pecten laevicostatus J de C Sowerby, Callista pseudoumbonella Vredenburg and Clementia papyracea (Gray) from Kachchh as against overall 42 forms from the Nari Series as a whole (Vredenburg 1928). This tempted us to make an attempt to collect bivalve fauna systematically which are occurring prolifically in the Ramanian Stage. In the present work, for this purpose, sections are worked out around Lakhpat (23° 50′N; 68

  11. Manifesting the Quantum World

    Science.gov (United States)

    Mohrhoff, Ulrich

    2014-06-01

    In resisting attempts to explain the unity of a whole in terms of a multiplicity of interacting parts, quantum mechanics calls for an explanatory concept that proceeds in the opposite direction: from unity to multiplicity. Being part of the Scientific Image of the world, the theory concerns the process by which (the physical aspect of) what Sellars called the Manifest Image of the world comes into being. This process consists in the progressive differentiation of an intrinsically undifferentiated entity. By entering into reflexive spatial relations, this entity gives rise to (i) what looks like a multiplicity of relata if the reflexive quality of the relations is not taken into account, and (ii) what looks like a substantial expanse if the spatial quality of the relations is reified. If there is a distinctly quantum domain, it is a non-spatial and non-temporal dimension across which the transition from the unity of this entity to the multiplicity of the world takes place. Instead of being constituents of the physical world, subatomic particles, atoms, and molecules are instrumental in its manifestation. These conclusions are based on the following interpretive principle and its more direct consequences: whenever the calculation of probabilities calls for the addition of amplitudes, the distinctions we make between the alternatives lack objective reality. Applied to alternatives involving distinctions between regions of space, this principle implies that, owing to the indefiniteness of positions, the spatiotemporal differentiation of the physical world is incomplete: the existence of a real-valued spatiotemporal background is an unrealistic idealization. This guarantees the existence of observables whose values are real per se, as against "real by virtue of being indicated by the values of observables that are real per se." Applied to alternatives involving distinctions between things, it implies that, intrinsically, all fundamental particles are numerically

  12. The miRNA biogenesis in marine bivalves.

    Science.gov (United States)

    Rosani, Umberto; Pallavicini, Alberto; Venier, Paola

    2016-01-01

    Small non-coding RNAs include powerful regulators of gene expression, transposon mobility and virus activity. Among the various categories, mature microRNAs (miRNAs) guide the translational repression and decay of several targeted mRNAs. The biogenesis of miRNAs depends on few gene products, essentially conserved from basal to higher metazoans, whose protein domains allow specific interactions with dsRNA. Here, we report the identification of key genes responsible of the miRNA biogenesis in 32 bivalves, with particular attention to the aquaculture species Mytilus galloprovincialis and Crassostrea gigas. In detail, we have identified and phylogenetically compared eight evolutionary conserved proteins: DROSHA, DGCR8, EXP5, RAN, DICER TARBP2, AGO and PIWI. In mussels, we recognized several other proteins participating in the miRNA biogenesis or in the subsequent RNA silencing. According to digital expression analysis, these genes display low and not inducible expression levels in adult mussels and oysters whereas they are considerably expressed during development. As miRNAs play an important role also in the antiviral responses, knowledge on their production and regulative effects can shed light on essential molecular processes and provide new hints for disease prevention in bivalves. PMID:26989613

  13. Ionic supramolecular bonds preserve mechanical properties and enable synergetic performance at high humidity in water-borne, self-assembled nacre-mimetics

    Science.gov (United States)

    Das, Paramita; Walther, Andreas

    2013-09-01

    Although tremendous effort has been focused on enhancing the mechanical properties of nacre-mimetic materials, conservation of high stiffness and strength against hydration-induced decay of mechanical properties at high humidity remains a fundamental challenge in such water-borne high-performance materials. Herein, we demonstrate that ionic supramolecular bonds, introduced by infiltration of divalent Cu2+ ions, allow efficient stabilization of the mechanical properties of self-assembled water-borne nacre-mimetics based on sustainable sodium carboxymethylcellulose (Na+CMC) and natural sodium montmorillonite nanoclay (Na+MTM) against high humidity (95% RH). The mechanical properties in the highly hydrated state (Young's modulus up to 13.5 GPa and tensile strength up to 125 MPa) are in fact comparable to a range of non-crosslinked nacre-mimetic materials in the dry state. Moreover, the Cu2+-treated nacre-inspired materials display synergetic mechanical properties as found in a simultaneous improvement of stiffness, strength and toughness, as compared to the pristine material. Significant inelastic deformation takes place considering the highly reinforced state. This contrasts the typical behaviour of tight, covalent crosslinks and is suggested to originate from a sacrificial, dynamic breakage and rebinding of transient supramolecular ionic bonds. Considering easy access to a large range of ionic interactions and alteration of counter-ion charge via external stimuli, we foresee responsive and adaptive mechanical properties in highly reinforced and stiff bio-inspired bulk nanocomposites and in other bio-inspired materials, e.g. nanocellulose papers and peptide-based materials.Although tremendous effort has been focused on enhancing the mechanical properties of nacre-mimetic materials, conservation of high stiffness and strength against hydration-induced decay of mechanical properties at high humidity remains a fundamental challenge in such water-borne high

  14. Pulmonary manifestation of leptospirosis

    International Nuclear Information System (INIS)

    Authors analysed and present chest X-ray findings of serologically proven leptospirosis from Seoul National University Hospital, either admitted or referred for serological verification, during recent 2 years. Radiological findings were correlated with the lung specimen findings of experimentally induced leptospirosis in guinea pig. The results are as follows: 1. 24 cases (56%) showed positive X-ray findings. 2. Predominant radiological patterns of involved lung were tiny dot, small nodule, rosette density in 11 cases, massive confluent consolidation in 4 cases, and diffuse ill-defined velly increased density in 9 cases. 3. Distribution of pulmonary lesions were bilateral (100%), non-lobar, non-segmental (95%), and there were conspicuous tendency of peripheral lung predominance. 4. Extrapulmonary manifestation, such as pleural effusion or cardiomegaly was rate. 5. Pulmonary lesions resolved completely usually 5 to 10 days after their appearance. 6. From the gross and microscopic findings of serially sacrificed guinea pig's lung and a case of autopsy, authors concluded that fine dot-like density in chest X-ray was due to paleolithic hemorrhage in intraalveolar space at initial stage, growing up to ressette density or confluent consolidation as the pathetic extends to surrounding lung forming purpura and coalescent hemorrhage.

  15. Manifesting the Quantum World

    CERN Document Server

    Mohrhoff, Ulrich

    2014-01-01

    In resisting attempts to explain the unity of a whole in terms of a multiplicity of interacting parts, quantum mechanics calls for an explanatory concept that proceeds in the opposite direction: from unity to multiplicity. It concerns the process by which what Sellars called the Manifest Image of the world comes into being. This process consists in the progressive differentiation of an intrinsically undifferentiated entity. By entering into reflexive spatial relations, this gives rise to (i) what looks like a multiplicity of relata if the reflexive quality of the relations is not taken into account, and (ii) what looks like a substantial expanse if the spatial quality of the relations is reified. If there is a distinctly quantum domain, it is a non-spatial and non-temporal dimension across which the transition from the unity of this entity to the multiplicity of the world takes place. Instead of being constituents of the physical world, subatomic particles, atoms, and molecules are instrumental in its manifes...

  16. Pulmonary manifestation of leptospirosis

    Energy Technology Data Exchange (ETDEWEB)

    Im, Jung Gi; Yeon, Kyung Mo; Han, Man Chung; Kim, Chu Wan; Lee, Jung Sang; Kim, Suhng Gwon; Han, Yong Chol; Chang, Woo Hyun; Chi, Je Geun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1986-02-15

    Authors analysed and present chest X-ray findings of serologically proven leptospirosis from Seoul National University Hospital, either admitted or referred for serological verification, during recent 2 years. Radiological findings were correlated with the lung specimen findings of experimentally induced leptospirosis in guinea pig. The results are as follows: 1. 24 cases (56%) showed positive X-ray findings. 2. Predominant radiological patterns of involved lung were tiny dot, small nodule, rosette density in 11 cases, massive confluent consolidation in 4 cases, and diffuse ill-defined velly increased density in 9 cases. 3. Distribution of pulmonary lesions were bilateral (100%), non-lobar, non-segmental (95%), and there were conspicuous tendency of peripheral lung predominance. 4. Extrapulmonary manifestation, such as pleural effusion or cardiomegaly was rate. 5. Pulmonary lesions resolved completely usually 5 to 10 days after their appearance. 6. From the gross and microscopic findings of serially sacrificed guinea pig's lung and a case of autopsy, authors concluded that fine dot-like density in chest X-ray was due to paleolithic hemorrhage in intraalveolar space at initial stage, growing up to ressette density or confluent consolidation as the pathetic extends to surrounding lung forming purpura and coalescent hemorrhage.

  17. Gastrointestinal manifestations of endocrine disease

    Institute of Scientific and Technical Information of China (English)

    Christina Maser; Arnbjorn Toset; Sanziana Roman

    2006-01-01

    The hormonal interactions among the systems throughout the body are not fully understood; many vague clinical symptoms may in fact be manifestations of underlying endocrine diseases. The aim of the following review is to discuss gastrointestinal manifestations of surgically correctable endocrine diseases, focusing on abnormalities of thyroid function, cancer and finally autoimmune diseases. We also review manifestations of pancreatic endocrine tumors, and multiple endocrine neoplasia.

  18. CT manifestation of hepatic toxoplasmosis

    International Nuclear Information System (INIS)

    Objective: To study the CT manifestation of hepatic toxoplasmosis, and to provide image basis for its clinical diagnosis. Methods: Three patients with hepatic toxoplasmosis were examined by abdomen MSCT (pre- and post-contrast), and were confirmed by laboratory exams. The images were analyzed with information of clinical manifestation. Results: The positive appearances included the enlargement of liver, patches of multiple scattered low densities. Post-contrast lesions appearances: (1) No significant enhancement. (2) No significant occupying effection, and normal vessels inserting lesion occasionally. Conclusion: CT manifestation of hepar toxoplasmosis are some characteristic. But the diagnosis was made by a combination both clinical manifestation and laboratory exams. (authors)

  19. The water-soluble matrix fraction from the nacre of Pinctada maxima produces earlier mineralization of MC3T3-E1 mouse pre-osteoblasts.

    Science.gov (United States)

    Rousseau, Marthe; Pereira-Mouriès, Lucilia; Almeida, Maria José; Milet, Christian; Lopez, Evelyne

    2003-05-01

    Nacre or mother of pearl is a calcified structure that forms the lustrous inner layer of some shells. We studied the biological activity of the water-soluble matrix (WSM) extracted from powdered nacre from the shell of the pearl oyster, Pinctada maxima, on the MC3T3-E1 pre-osteoblast cell line from mouse calvaria. This cell line has the ability to differentiate into osteoblasts and to mineralize in the presence of beta-glycerophosphate and ascorbic acid. Cell proliferation and alkaline phosphatase activity were measured as markers of osteoblast differentiation, and mineralization was analyzed. These studies revealed that WSM stimulates osteoblast differentiation and mineralization by day 6 instead of the 21-day period required for cells grown in normal mineralizing media. We compared the activity of WSM with that of dexamethasone on this cell line. WSM can inhibit alkaline phosphatase (ALP) activity and the activity of dexamethasone on MC3T3-E1 cells. This study shows that nacre WSM could speed up the differentiation and mineralization of this cell line more effectively than dexamethasone. PMID:12781967

  20. Oral manifestations of vitiligo

    Directory of Open Access Journals (Sweden)

    Anitha Nagarajan

    2015-01-01

    Full Text Available Background: Vitiligo is one of the disorder that has social impact . Both skin and mucous membrane show depigmentation in vitiligo. Depigmentation in oral cavity can be more easily observed and the patient can be given awareness regarding the condition if they are unaware of vitiligo elsewhere in their body and can be guided for treatment. Aim and objectives: The aim of this study is to determine the frequency of occurrence of oral mucosal vitiligo in vitiligo patients and to determine the most commonly involved oral mucosal site. Materials and methods: The study sample included 100 vitiligo patients. The patients of all age groups and both genders were included. Vitiligo patients associated with systemic conditions such as thyroid disorders, juvenile diabetes mellitus, pernicious anemia, Addison′s disease were excluded in this study. Results: Out of 100 vitiligo patients 44 % male and 56% were female. The oral presentation of vitiligo in this study showed depigmentation of buccal mucosa in 5% of patients, labial mucosa in 5% of patients, palate in 8% of patients, gingiva in 2% of patients and alveolar mucosa 1% . Depigmentation of lip was seen in 42% of patients. Lip involvement refers to depigmentation of both the lips or either lip. Also vermilion border involvement was noted in majority of cases. In some cases, the depigmentation of lip extended to the facial skin also. Conclusion: In this study 55 patients out of 100 patients showed depigmentation in the oral cavity. Lip involvement was most common in this study showing about 42% of patients. Intraoral mucosal involvement was found in 21% of patients. Among intraoral mucosal site palate was common followed by buccal and labial mucosa, gingiva. Two patients had lip pigmentation as the only manifestation without any depigmentation in the skin.

  1. Selective extinction among Early Jurassic bivalves: A consequence of anoxia

    Science.gov (United States)

    Aberhan, Martin; Baumiller, Tomasz K.

    2003-12-01

    Analyses of taxonomically standardized data sets demonstrate several statistically robust extinction patterns in Early Jurassic bivalve species from northwest Europe and the Andean basins of South America. In both regions, extinction intensities were significantly enhanced in late Pliensbachian and early Toarcian time as compared to all other time intervals. The same intervals (except for the early Toarcian of South America) also represent times of unusual extinction selectivity, with infaunal taxa suffering distinctly more than epifaunal forms. As infaunal suspension feeders are extremely rare components of Early Jurassic oxygen-controlled macrofaunas, these results are entirely compatible with sedimentological and geochemical data suggesting that widespread anoxia was a principal cause of the diversity crisis. Although many biotic traits that enhance survivorship during background times seem to be irrelevant during major mass extinctions, patterns of survivorship selectivity may provide more distinct clues to the causes of less severe mass extinctions.

  2. Evolutionary implications of endosymbiont diversity within lucinid bivalves

    Science.gov (United States)

    Garcia, A. M.; Thiessen, M.; Aronowsky, A.; Anderson, L.; Bao, H.; Engel, A.

    2007-12-01

    Bacterial endosymbiosis is widespread among Bivalvia. Symbiosis between lucinid bivalves and sulfur-oxidizing (thiotrophic) bacteria has received recent attention, as lucinids are one of the geologically oldest extant bivalve clades to possess endosymbionts. However, the ecological and evolutionary relationships between host and symbiont are poorly understood, and reconstructing the evolutionary history and geological significance of lucinid endosymbiosis requires additional knowledge and characterization of endosymbiont ecology and taxonomic diversity. Our goal was to characterize the bacterial diversity of a modern lucinid habitat in order to evaluate possible lucinid endosymbiont diversity. Host organisms ( Lucinisca nassula and Phacoides pectinatus) and sediment cores were collected from geochemically reducing and sulfide-rich sea grass beds. PCR amplification and sequencing of bacterial 16S rRNA genes from the sediment cores retrieved 13 major taxonomic groups, including equally dominant Chloroflexi, Delta-, and Gammaproteobacteria, and rare Bacteroides, Acidobacteria, Spirochaetes, and Firmicutes. Less than 2% of the sequences were affiliated with uncultured gammaproteobacterial symbiont groups, but were not closely related to the sequences retrieved from the lucinid gills. Moreover, our analyses uncovered multiple gene sequence populations within an individual, as well as across individuals within the same sampling site. Additional habitat-host-symbiont diversity from three other lucinid taxa and from six geographically distinct habitat sites is also expanding the previously understood diversity of thiotrophic endosymbionts, and specifically that the lucinid symbionts are probably not a monophyletic species. These data suggest that thiotrophic bacteria are recruitable for endosymbiosis and are widely distributed in reducing marine environments. But, because of the diversity of bacteria in any one habitat, symbionts may be metabolically and physiologically

  3. Magnetosome-containing bacteria living as symbionts of bivalves.

    Science.gov (United States)

    Dufour, Suzanne C; Laurich, Jason R; Batstone, Rebecca T; McCuaig, Bonita; Elliott, Alexander; Poduska, Kristin M

    2014-12-01

    Bacteria containing magnetosomes (protein-bound nanoparticles of magnetite or greigite) are common to many sedimentary habitats, but have never been found before to live within another organism. Here, we show that octahedral inclusions in the extracellular symbionts of the marine bivalve Thyasira cf. gouldi contain iron, can exhibit magnetic contrast and are most likely magnetosomes. Based on 16S rRNA sequence analysis, T. cf. gouldi symbionts group with symbiotic and free-living sulfur-oxidizing, chemolithoautotrophic gammaproteobacteria, including the symbionts of other thyasirids. T. cf. gouldi symbionts occur both among the microvilli of gill epithelial cells and in sediments surrounding the bivalves, and are therefore facultative. We propose that free-living T. cf. gouldi symbionts use magnetotaxis as a means of locating the oxic-anoxic interface, an optimal microhabitat for chemolithoautotrophy. T. cf. gouldi could acquire their symbionts from near-burrow sediments (where oxic-anoxic interfaces likely develop due to the host's bioirrigating behavior) using their superextensile feet, which could transfer symbionts to gill surfaces upon retraction into the mantle cavity. Once associated with their host, however, symbionts need not maintain structures for magnetotaxis as the host makes oxygen and reduced sulfur available via bioirrigation and sulfur-mining behaviors. Indeed, we show that within the host, symbionts lose the integrity of their magnetosome chain (and possibly their flagellum). Symbionts are eventually endocytosed and digested in host epithelial cells, and magnetosomes accumulate in host cytoplasm. Both host and symbiont behaviors appear important to symbiosis establishment in thyasirids. PMID:24914799

  4. Life history traits to predict biogeographic species distributions in bivalves

    Science.gov (United States)

    Montalto, V.; Rinaldi, A.; Sarà, G.

    2015-10-01

    Organismal fecundity ( F) and its relationship with body size (BS) are key factors in predicting species distribution under current and future scenarios of global change. A functional trait-based dynamic energy budget (FT-DEB) is proposed as a mechanistic approach to predict the variation of F and BS as function of environmental correlates using two marine bivalves as model species ( Mytilus galloprovincialis and Brachidontes pharaonis). Validation proof of model skill (i.e., degree of correspondence between model predictions and field observations) and stationarity (i.e., ability of a model generated from data collected at one place/time to predict processes at another place/time) was provided to test model performance in predicting the bivalve distribution throughout the 22 sites in the Central Mediterranean Sea under local conditions of food density and body temperature. Model skill and stationarity were tested through the estimate of commission (i.e., proportion of species' absences predicted present) and omission (i.e., proportion of presences predicted absent) errors of predictions by comparing mechanistic predicted vs. observed F and BS values throughout the study area extrapolated by lab experiments and literature search. The resulting relationship was reliable for both species, and body size and fecundity were highly correlated in M. galloprovincialis compared to B. pharaonis; FT-DEB showed correct predictions of presence in more than 75 % of sites, and the regression between BS predicted vs. observed was highly significant in both species. Whilst recognising the importance of biotic interactions in shaping the distribution of species, our FT-DEB approach provided reliable quantitative estimates of where our species had sufficient F to support local populations or suggesting reproductive failure. Mechanistically, estimating F and BS as key traits of species life history can also be addressed within a broader, scale-dependent context that surpasses the

  5. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analyses of mineral and organic matrix during heating of mother of pearl (nacre) from the shell of the mollusc Pinctada maxima.

    Science.gov (United States)

    Balmain, J; Hannoyer, B; Lopez, E

    1999-01-01

    Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction patterns were used to analyze the mineral structure and organic matrix composition and thermal behavior of the internal nacreous layer (mother of pearl or nacre) of the shell of the giant oyster Pinctada maxima. Nacre is a natural biomaterial with osteogenic properties. The mineral of nacre is calcium carbonate crystallized as aragonite and it is highly crystallized. The FT-IR spectra showed amide, amine, and carboxylic acid groups in the organic matrix of the whole (organic and mineral) nacreous layer, with the HCO(-)(3) groups possibly at the organic-mineral interface. The insoluble organic matrix remaining after decalcification contained amide, amine, and carboxylic groups. The heated aragonite mineral structure of nacre underwent two transformations (X-ray diffraction), aragonite to calcite at 300-400 degrees C, and calcite to calcium oxide (CaO) at 500-600 degrees C. The organic matrix of nacre was destroyed around 550-600 degrees C, the same temperature as the calcite to CaO transformation, revealing the great thermal stability of the organic matrix and the organic-mineral bonding. This could be an useful feature for the in vivo use of this natural biomaterial as an implant. PMID:10490692

  6. 40 CFR 262.21 - Manifest tracking numbers, manifest printing, and obtaining manifests.

    Science.gov (United States)

    2010-07-01

    ... instructions in the appendix to 40 CFR part 262 must appear legibly on the back of the copies of the manifest... available information to do so (e.g., corporate brochures, product samples, customer references... binding method; or (ii) Exhibits a continuing pattern of behavior in using or distributing manifests...

  7. Metals and organotins in multiple bivalve species in a one-off global survey

    DEFF Research Database (Denmark)

    Larsen, Martin Mørk; Strand, Jakob; Christensen, Jan H.;

    2011-01-01

    contamination levels on a global scale. Metal concentrations in nine bivalve species were normalised to the Mytilidae family using conversion factors based on cosampled species and literature bioconcentration factors. The lowest metal and tributyltin concentrations were below background assessment...

  8. Independent phylogenetic origins of methanotrophic and chemoautotrophic bacterial endosymbioses in marine bivalves

    OpenAIRE

    Distel, D L; Cavanaugh, Colleen Marie

    1994-01-01

    The discovery of bacterium-bivalve symbioses capable of utilizing methane as a carbon and energy source indicates that the endosymbionts of hydrothermal vent and cold seep bivalves are not restricted to sulfur-oxidizing chemoautotrophic bacteria but also include methanotrophic bacteria. The phylogenetic origin of methanotrophic endosymbionts and their relationship to known symbiotic and free-living bacteria, however, have remained unexplored. In situ localization and phylogenetic analysis of ...

  9. Influence of intertidal recreational fisheries and 'bouchot' mussel culture on bivalve recruitment.

    Science.gov (United States)

    Toupoint, Nicolas; Barbier, Pierrick; Tremblay, Réjean; Archambault, Philippe; McKindsey, Christopher W; Winkler, Gesche; Meziane, Tarik; Olivier, Frédéric

    2016-06-01

    In coastal environments, fishing and aquaculture may be important sources of disturbance to ecosystem functioning, the quantification of which must be assessed to make them more sustainable. In the Chausey Archipelago, France, recreational fishing and commercial shellfish farming are the only two evident anthropogenic activities, dominated by bivalve hand-raking and 'bouchot' mussel culture, respectively. This study evaluates the impact of both activities on bivalve recruitment dynamics by comparing primary recruitment intensity (short-term effect) and recruitment efficiency (medium-term effect) by sampling bivalves in reference (undisturbed) and disturbed (i.e. subjected to hand-raking or in 'bouchot' mussel culture areas) parcels throughout and at the end of the recruitment season, respectively. Specific hypotheses evaluated were that (H1) bivalve hand-raking negatively affects bivalve recruitment and that (H2) 'bouchot' mussel culture promotes bivalve recruitment. Patterns in bivalve community structure in reference parcels (i.e. natural pattern) differed between initial and final recruitment, underlining the great importance of early post-settlement processes, particularly secondary dispersal. Primary recruitment intensity was inhibited in hand-raking parcels whereas it was promoted in 'bouchot' mussel culture parcels, but the effect on recruitment efficiency was muted for both activities due to post-settlement processes. Nevertheless, the importance of effects that occur during the first step of recruitment should not be ignored as they may affect bivalve communities and induce immediate consequences on the trophic web through a cascade effect. Finally, it is highlighted that hand-raking damages all life stages of the common cockle Cerastoderma edule, one of the major target species, suggesting that this activity should be managed with greater caution than is currently done. PMID:27039134

  10. An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

    OpenAIRE

    Duperron, S.; Gaudron, S.M.; Rodrigues, C. F.; M. R. Cunha; C. Decker; Olu, K

    2012-01-01

    Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria which ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, East America, the Gulf o...

  11. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... KIDNEY) MANIFESTATIONS IN TSC Download a PDF of this information. The majority of individuals (greater than 80 ... lead to bleeding. About 20% of the time this bleeding is life-threatening. Approximately 80 percent of ...

  12. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... For Healthcare Professionals For Researchers & Scientists For School Issues What Is TSC? How Is TSC Diagnosed? Signs ... National Resources Infantile Spasms & TSC Seizures & TSC TSC & Autism HEALTHCARE PROFESSIONALS Clinical Manifestations Diagnostic Criteria Publications Clinical ...

  13. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... History Database Tissue Donation Audio & Video Archives Brochures, Books, & Booklets Information Sheets Perspective Magazine Archives Life Stages ... Scientific Advisory Board 2015 International TSC Research Conference Text Size Get Involved RENAL (KIDNEY) MANIFESTATIONS IN TSC ...

  14. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... Resources Young Adult Resources Family Support TSC Connect Publications & Information Sheets TSC Clinics Physician Referral TSC Clinical ... Presentations Clinical Manifestations Diagnostic Criteria TSC Consensus ... Clinical Trials Tissue Donation Professional Advisory Board Professional ...

  15. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... Get Involved RENAL (KIDNEY) MANIFESTATIONS IN TSC Download a PDF of this information. The majority of individuals ( ... the least common renal association with TSC, is a cancerous growth of the kidney. Although it is ...

  16. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... Magazine Archives Life Stages Guides & Personal Journals TSC Research Article Summaries 2014 World TSC Conference Session Videos Research Teleconference Presentations Clinical Manifestations Diagnostic Criteria TSC Consensus ...

  17. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... For the Newly Diagnosed For Individuals & Families For Healthcare Professionals For Researchers & Scientists For School Issues What ... Resources Infantile Spasms & TSC Seizures & TSC TSC & Autism HEALTHCARE PROFESSIONALS Clinical Manifestations Diagnostic Criteria Publications Clinical Trials ...

  18. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... Resources Young Adult Resources Family Support TSC Connect Publications & Information Sheets TSC Clinics Physician Referral TSC Clinical ... Presentations Clinical Manifestations Diagnostic Criteria TSC ... Clinical Trials Tissue Donation Professional Advisory Board Professional ...

  19. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... the high risk of further growth and the development of symptoms, consideration should be given to oral ... Infantile Spasms & TSC Seizures & TSC TSC & Autism HEALTHCARE PROFESSIONALS Clinical Manifestations Diagnostic Criteria Publications Clinical Trials Tissue ...

  20. Renal (Kidney) Manifestations in TSC

    Medline Plus

    Full Text Available ... Publications & Information Sheets TSC Clinics Physician Referral TSC Clinical Trials TSC Natural History Database Tissue Donation Audio & Video ... Clinical Manifestations Diagnostic Criteria TSC Consensus Recommendations ... Tissue Donation Professional Advisory Board Professional Referral List ...

  1. Synergistic toughening of hard, nacre-mimetic MoSi2 coatings by self-assembled hierarchical structure

    Science.gov (United States)

    Xu, Jiang; Zhao, Xiaoli; Munroe, Paul; Xie, Zonghan

    2014-02-01

    Like many other intermetallic materials, MoSi2 coatings are typically hard, but prone to catastrophic failure due to their low toughness at ambient temperature. In this paper, a self-assembled hierarchical structure that closely resembles that of nacre (i.e., mother of pearl) was developed in a MoSi2-based coating through a simple, yet cost-effective, depostion technique. The newly formed coating is tough and can withstand multiple indentations at high loads. Key design features responsible for this remarkable outcome were identified. They include a functionally graded multilayer featuring elastic modulus oscillation, varying sublayer thickness and a columnar structure that are able to attenuate stress concentrations; interlocking boundaries between adjacent sublayers that improve the bonding and arrest the cracks; a transitional layer that bridges the coating and substrate and facilitates load transfer. Moreover, the contributions of six important structural characteristics to damage resistance are quantified using finite elemnet analysis and in an additive manner (i.e., from low- to high-level complexity). The in-situ toughened coating is envisaged to enhance the mechanical performance and extend the lifespan of metal components used in safety-critical applications.

  2. Synergistic toughening of hard, nacre-mimetic MoSi2 coatings by self-assembled hierarchical structure.

    Science.gov (United States)

    Xu, Jiang; Zhao, Xiaoli; Munroe, Paul; Xie, Zonghan

    2014-01-01

    Like many other intermetallic materials, MoSi2 coatings are typically hard, but prone to catastrophic failure due to their low toughness at ambient temperature. In this paper, a self-assembled hierarchical structure that closely resembles that of nacre (i.e., mother of pearl) was developed in a MoSi2-based coating through a simple, yet cost-effective, depostion technique. The newly formed coating is tough and can withstand multiple indentations at high loads. Key design features responsible for this remarkable outcome were identified. They include a functionally graded multilayer featuring elastic modulus oscillation, varying sublayer thickness and a columnar structure that are able to attenuate stress concentrations; interlocking boundaries between adjacent sublayers that improve the bonding and arrest the cracks; a transitional layer that bridges the coating and substrate and facilitates load transfer. Moreover, the contributions of six important structural characteristics to damage resistance are quantified using finite elemnet analysis and in an additive manner (i.e., from low- to high-level complexity). The in-situ toughened coating is envisaged to enhance the mechanical performance and extend the lifespan of metal components used in safety-critical applications. PMID:24577416

  3. Cardiopulmonary Manifestations of Ankylosing Spondylitis

    OpenAIRE

    Mahnaz Momeni; Nora Taylor; Mahsa Tehrani

    2011-01-01

    Ankylosing spondylitis is a chronic inflammatory condition that usually affects young men. Cardiac dysfunction and pulmonary disease are well-known and commonly reported extra-articular manifestation, associated with ankylosing spondylitis (AS). AS has also been reported to be specifically associated with aortitis, aortic valve diseases, conduction disturbances, cardiomyopathy and ischemic heart disease. The pulmonary manifestations of the disease include fibrosis of the upper lobes, intersti...

  4. The radiographic manifestations of hypochondroplasia

    International Nuclear Information System (INIS)

    Hypochrondroplasia is an inherited skeletal dysplasia that resembles achondroplasia in mild degree. Radiographic manifestations encountered in 12 affected individuals in South Africa include slight shortening of all segments of the tubular bones, moderate caudal diminution of the lumbar interpedicular distances, increased lumbar lordosis with cacral tilt and distal prolongation of the fibular. Hypochondroplasia can be distinguished from other osteochondrodystrophies such as achondroplasia, pseudo-achondroplasia and metaphyseal chondroplasia by the recognition of it clinical and radiographic manifestations. (author)

  5. Oral Manifestations of Secondary Syphilis

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Barbosa de Paulo

    2015-06-01

    Full Text Available Known as “the great imitator,” secondary syphilis may clinically manifest itself in myriad ways, involving different organs including the oral mucosa, and mimicking, both clinically and histologically, several diseases, thereby making diagnosis a challenge for clinicians. We highlight the clinical aspects of oral manifestation in 7 patients with secondary syphilis. Clinicians should consider secondary syphilis in the differential diagnosis of ulcerative and/or white oral lesions.

  6. Unusual clinical manifestations of leptospirosis

    OpenAIRE

    Bal A

    2005-01-01

    Leptospirosis has protean clinical manifestations. The classical presentation of the disease is an acute biphasic febrile illness with or without jaundice. Unusual clinical manifestations may result from involvement of pulmonary, cardiovascular, neural, gastrointestinal, ocular and other systems. Immunological phenomena secondary to antigenic mimicry may also be an important component of many clinical features and may be responsible for reactive arthritis. Leptospirosis in early pregnancy may...

  7. An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

    DEFF Research Database (Denmark)

    Filgueira, Ramón; Byron, C.J.; Comeau, L.A.;

    2015-01-01

    The role of bivalve mariculture in the CO2 cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO2 release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities......, e.g. the impact on phytoplankton dynamics and benthic-pelagic coupling, which can significantly contribute to the CO2 cycle. Therefore, an ecosystem approach that accounts for the trophic interactions of bivalve aquaculture, including dissolved and particulate organic and inorganic carbon cycling......, is needed to provide a rigorous assessment of the role of bivalve mariculture in the CO2 cycle. On the other hand, the discussion about the inclusion of shells of cultured bivalves into the carbon trading system should be framed in the context of ecosystem goods and services. Humans culture bivalves...

  8. Strontium and barium incorporation into freshwater bivalve shells

    Science.gov (United States)

    Zhao, Liqiang; Schöne, Bernd R.

    2015-04-01

    Despite strong vital control, trace elements of bivalve shells can potentially serve as proxies of environmental change. However, to reconstruct past environments with the geochemical properties of the shells and determine the degree to which the element levels are biologically influenced, it is essential to experimentally determine the relationship between environmental variables and the element composition of the shells. In particular, the trace element geochemistry of freshwater bivalve shells has so far received little attention. Here, we present a controlled laboratory experiment that aimed at providing a better understanding of the influence of changing environmental variables on the incorporation of trace elements into freshwater bivalve shells. Under controlled conditions, Asian clams Corbicula fluminea were reared for 5 weeks in three sets of experiments: (1) different water temperature (10, 16, and 22° C) and different food levels (an equally mixed Scenedesmu quadricanda and Chlorella vulgaris at rations of 0.4, 2, 4, and 8 × 104 cells ml-1 d-1); (2) different water temperature (10, 16, and 22° C) and different element levels (Sr, Ba); (3) five sediment types (sand, slightly muddy sand, muddy sand, slightly sandy mud and mud). In the first set of experiments, shell Sr/Ca showed a significantly negative correlation with temperature, where Sr/Ca decreased linearly by about 1.6 to 2.1% per 1° C, but responded far more weakly to food availability. On the other hand, temperature and food availability affected shell Ba/Ca ratios, which potentially confounds the interpretation of Ba/Ca variations. Moreover, shell Sr/Ca and Ba/Ca exhibited a clearly negative dependence on shells growth rate that varied significantly among combinations of temperature and food availability. In the second set of experiments, shell Sr/Ca and Ba/Ca were positively and linearly related to water Sr/Ca and Ba/Ca for all temperatures. However, significantly negative effects of

  9. Anoxic survival potential of bivalves: (arte)facts.

    Science.gov (United States)

    de Zwaan, Albertus; Babarro, Jose M F; Monari, Marta; Cattani, Otello

    2002-03-01

    The anoxic survival time of the bivalves Chamelea gallina, Cerastoderma edule and Scapharca inaequivalvis from two different ecosystems and differing anoxia tolerances was studied in static (closed) and flow-through systems. The antibiotics chloramphenicol, penicillin and polymyxin were added, and molybdate (specific inhibitor of the process of sulfate reduction). Survival in (near) anoxic seawater of Chamelea was studied in a static system by comparing untreated seawater with autoclaved seawater and untreated clams with clams incubated in well-aerated seawater, containing the broad-spectrum antibiotic chloramphenicol, prior to the anoxic survival test. With untreated clams and natural seawater (median mortality time 2.4 days) a decrease in pH and exponential accumulation of sulfide and ammonium was observed in the anoxic medium, indicating excessive growth of (sulfate reducing) bacteria. In sterilized seawater LT50 (2.1 days) was not significantly different and again considerable amounts of ammonium and sulfide accumulated. However, pre-treatment of clams with chloramphenicol resulted in an increase of LT50 (11.0 days) by approximately fivefold. Accumulation of ammonium and sulfide was retarded, but was finally even stronger than in the medium containing untreated clams. Median mortality times were 2.5 and 2.4 days for Chamelea and 2.7 and 2.9 days for Cerastoderma for static and flow-through incubations, respectively. Addition of chloramphenicol increased strongly survival time in both systems with corresponding values of 11.0 and 16.3 days for Chamelea, and 6.4 and 6.5 days for Cerastoderma. LT50 of Scapharca in anoxic seawater was 14.4 days. Chloramphenicol and penicillin increased median survival time to 28.5 and 28.7 days, respectively, whereas polymyxin displayed no effect (LT50=13.6 days). Molybdate added to artificial sulfate free seawater blocked biotic sulfide formation, but did not improve survival time (LT50=13.7 days). Overall the results indicate

  10. Proteomic Profiling of Cytosolic Glutathione Transferases from Three Bivalve Species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea

    OpenAIRE

    José Carlos Martins; Alexandre Campos; Hugo Osório; Rute da Fonseca; Vítor Vasconcelos

    2014-01-01

    Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs), in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST) were surveyed in three bivalves with different habitats and life strategies: ...

  11. Trace Element Uptake in Marine Bivalve Shells Constraints from Field- and Laboratory Studies

    Science.gov (United States)

    Klünder, M.; Hippler, D.; Witbaard, R.; Frei, D.; Immenhauser, A.

    2006-12-01

    There is an increasing interest in the use of the trace element signatures recorded in calcium carbonate skeletons of marine organisms as archives of past and present environmental conditions, such as temperature, salinity or nutrition level. Because of their global occurrence in the modern and ancient oceans, the trace element chemistry of bivalve shells might be used as a potential proxy for present and past environmental conditions. If the composition of bivalve shells, for instance, can be shown to represent the environment in which they lived, then shells can be used to investigate conditions in the lifetime of the animal. And as the shell material is sequentially deposited, an understanding of the internal shell structure will enable time- resolution of the analyses. Therefore, the trace element signature of bivalve shells may provide an important record of climate changes and global geochemical cycles. One of the difficulties of using the trace element signatures of bivalve shells as proxies for environmental conditions is that little is known about the mechanisms by which the trace elements are incorporated into the shells. There has been quite an amount of research into the use of bivalve shell chemistry as proxy for one or more environmental parameters, but there are relatively few datasets in which both bivalve shells and the water in which the animals lived have been analysed. It is as yet not clear to what extent the trace element incorporation into bivalve shells is governed by biological processes, like growth rate and metabolism of the animals, or by physical and crystal chemical parameters. An added difficulty is that the existing data do suggest that trace element uptake in bivalve shells may be species specific. Therefore, studies that investigate the relationships between the content of these elements in the shells and the ambient water and the possible incorporation mechanisms are needed if the potential that bivalve shells offer as

  12. Changing restoration rules: exotic bivalves interact with residence time and depth to control phytoplankton productivity

    Science.gov (United States)

    Lucas, Lisa V.; Thompson, Janet K.

    2012-01-01

    Non-native species are a prevalent ecosystem stressor that can interact with other stressors to confound resource management and restoration. We examine how interactions between physical habitat attributes and a particular category of non-native species (invasive bivalves) influence primary production in aquatic ecosystems. Using mathematical models, we show how intuitive relationships between phytoplankton productivity and controllable physical factors (water depth, hydraulic transport time) that hold in the absence of bivalves can be complicated—and even reversed—by rapid bivalve grazing. In light-limited environments without bivalves, shallow, hydrodynamically “slow” habitats should generally have greater phytoplankton biomass and productivity than deeper, “faster” habitats. But shallower, slower environments can be less productive than deeper, faster ones if benthic grazing is strong. Moreover, shallower and slower waters exhibit a particularly broad range of possible productivity outcomes that can depend on whether bivalves are present. Since it is difficult to predict the response of non-native bivalves to habitat restoration, outcomes for new shallow, slow environments can be highly uncertain. Habitat depth and transport time should therefore not be used as indicators of phytoplankton biomass and production where bivalve colonization is possible. This study provides for ecosystem management a particular example of a broad lesson: abiotic ecosystem stressors should be managed with explicit consideration of interactions with other major (including biotic) stressors. We discuss the applicability and management implications of our models and results for a range of aquatic system types, with a case study focused on the Sacramento-San Joaquin Delta (California, USA). Simple mathematical models like those used here can illuminate interactions between ecosystem stressors and provide process-based guidance for resource managers as they develop strategies

  13. Intracellular Oceanospirillales bacteria inhabit gills of Acesta bivalves.

    Science.gov (United States)

    Jensen, Sigmund; Duperron, Sébastien; Birkeland, Nils-Kåre; Hovland, Martin

    2010-12-01

    A novel bacterium was discovered in the gills of the large bivalve Acesta excavata (Limidae) from coral reefs on the northeast Atlantic margin near the shelf break of the fishing ground Haltenbanken of Norway, and confirmed present in A. excavata from a rock-wall in the Trondheimsfjord. Purified gill DNA contained one dominant bacterial rRNA operon as indicated from analysis of broad range bacterial PCR amplicons in denaturant gradient gels, in clone libraries and by direct sequencing. The sequences originated from an unknown member of the order Oceanospirillales and its 16S rRNA gene fell within a clade of strictly marine invertebrate-associated Gammaproteobacteria. Visual inspection by fluorescent in situ hybridization and transmission electron microscopy indicated a pleomorphic bacterium with no visible cell wall, located in aggregates inside vacuoles scattered within the gill cells cytoplasm. Intracellular Oceanospirillales exist in bathymodiolin mussels (parasites), Osedax worms and whiteflies (symbionts). This bacterium apparently lives in a specific association with the Acesta. PMID:21044098

  14. Cutaneous manifestations in celiac disease

    Institute of Scientific and Technical Information of China (English)

    L Abenavoli; G Addolorato; I Proietti; L Leggio; A Ferrulli; L Vonghia; R Capizzi; M Rotoli; PL Amerio; G Gasbarrini

    2006-01-01

    Celiac disease (CD) is an autoimmune gluten-dependent enteropathy characterized by atrophy of intestinal villi that improves after gluten-free diet (GFD). CD is often associated with extra-intestinal manifestations;among them, several skin diseases are described in CD patients. The present review reports all CD-associated skin manifestations described in the literature and tries to analyze the possible mechanisms involved in this association. The opportunity to evaluate the possible presence of CD in patients affected by skin disorders is discussed.

  15. Bio-accumulation kinetics of radioruthenium in marine bivalves. Laboratory study

    International Nuclear Information System (INIS)

    Three kinds of marine bivalves (wild Saccostrea cucullata, aquacultured Perna viridis and aquacultured Pinctada martens), collected from Daya Bay, the South China Sea, were used to investigate the bio-accumulation of radioruthenium in the glass aquarium with natural seawater (pH 8.20, 35 per mille salinity, filtered by 0.45 μm) at ambient temperature under laboratory feeding conditions. The experimental results show that the stead-state of biology concentration factor (BCF, ml/g) of radioruthenium was approached around 6 days for most species of bivalves. The values of BCF in shells are the highest in organs all the three bivalves. The orders of BCF values (ml x g-1) are as: Perna viridis (33.2) < Saccostrea cucullata (47.0) < Pinctada martensi (208.4) for shells and Saccostrea cucullata (1.5) < Pinctada martensi (2.2) ∼ Perma viridis (2.4) for soft tissues, respectively, after exposed for 14 days. The rate constants of uptake and elimination of radioruthenium on marine bivalves were also discussed by first-order kinetics model. The Pinctada martensi may be applicable to be an indictor for monitoring radioruthenium among the three bivalves. (author)

  16. The earliest post-paleozoic freshwater bivalves preserved in coprolites from the karoo basin, South Africa.

    Directory of Open Access Journals (Sweden)

    Adam M Yates

    Full Text Available BACKGROUND: Several clades of bivalve molluscs have invaded freshwaters at various times throughout Phanerozoic history. The most successful freshwater clade in the modern world is the Unionoida. Unionoids arose in the Triassic Period, sometime after the major extinction event at the End-Permian boundary and are now widely distributed across all continents except Antarctica. Until now, no freshwater bivalves of any kind were known to exist in the Early Triassic. PRINCIPAL FINDINGS: Here we report on a faunule of two small freshwater bivalve species preserved in vertebrate coprolites from the Olenekian (Lower Triassic of the Burgersdorp Formation of the Karoo Basin, South Africa. Positive identification of these bivalves is not possible due to the limited material. Nevertheless they do show similarities with Unionoida although they fall below the size range of extant unionoids. Phylogenetic analysis is not possible with such limited material and consequently the assignment remains somewhat speculative. CONCLUSIONS: Bivalve molluscs re-invaded freshwaters soon after the End-Permian extinction event, during the earliest part of the recovery phase during the Olenekian Stage of the Early Triassic. If the specimens do represent unionoids then these Early Triassic examples may be an example of the Lilliput effect. Since the oldest incontrovertible freshwater unionoids are also from sub-Saharan Africa, it is possible that this subcontinent hosted the initial freshwater radiation of the Unionoida. This find also demonstrates the importance of coprolites as microenvironments of exceptional preservation that contain fossils of organisms that would otherwise have left no trace.

  17. Organohalogenated contaminants in sediments and bivalves from the Northern Arabian Gulf.

    Science.gov (United States)

    Ali, Nadeem; Ali, Lulwa Naseer; Eqani, Syed Ali Musstjab Akber Shah; Ismail, Iqbal Mohammad Ibrahim; Malarvannan, Govindan; Kadi, Mohammad W; Al-Badry Basahi, Jalal Mohammed; Covaci, Adrian

    2015-12-01

    Several classes of Organohalogenated contaminants (OHCs) were determined in sediments and bivalves collected from Kuwait coast. The levels and profile of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) were compared in both sediments and bivalves. PCB-153 and -138 were the major contributors towards total OHCs followed by DDT and its metabolites (DDTs). The higher contribution of DDTs (~40%) and BDE-47 (~15%) in bivalves as compared to that in associated sediments indicated high biota-sediment accumulation factors (BSAF). Higher BSAF (values for heavier PCBs, DDTs and PBDEs) also indicated their high accumulation potential from sediment into associated biota at most of the studied locations. Overall, OHCs in sediments and bivalves measured in current study were lower than those reported in the literature worldwide. Most of the sediment concentrations of OHCs (ng/g, dry weight) were in the range of permissible guideline values proposed by Canadian Sediment Quality Guidelines (CSQGs), with few exceptions for DDTs (5 ng/g) and PCBs (22.7 ng/g). Similarly, 10% of bivalve samples contained high levels (ng/g, lipid weight) of PCBs (300) and DDTs (150) and were above the set safety benchmarks. This study establishes baseline for future monitoring programs. PMID:26386334

  18. Organochlorine pollutants level in teleost fish and bivalve from Egyptian Mediterranean coast and Nile Estuary

    International Nuclear Information System (INIS)

    Residue levels of 15 organochlorine pollutants and 3 aroclors were analyzed by capillary Gas Chromatography GC in fish Mugil cephalus and bivalve Donax sp., collected from three different locations, at EI-Mex bay, Balteem and Rosetta. The studied pollutants were DDT's isomers, HCHs isomers as well as cyclodiene compounds, Mirex, methoxychlor, toxaphene and hexachlorobenzene (HCB), Aroclors 1248, 1254 and 1260 in addition to 10 individual PCBs congeners. Lipid content percentage ranged from 2.2 to 3.6% in fish and 1.0 to 1.5 % in bivalve, as judged by extractable Organic Matter (EOM) values. Lindane dominated the alph-isomer, with highest concentration 4.6 ng/g in fish from EI-Mex. p,p'-DDE dominated other DDTs analogs with the highest concentrations in fish 15.6 ng/g) and bivalve (9.9 ng/g) from Rosetta. Toxaphene was detected in all locations with maximum levels 13.0 and 11.0 ng/g in bivalve and fish respectively, from Rosetta. Aroclor 1248 dominated other aroclors in both fish and bivalve. For individual PCBs 153 congener dominated other congeners with lower chlorinated biphenyls (mono-through penta-chloro-biphenyls) congeners occurred at lower levels except PCB 200 and PCB 206. (author)

  19. Taxonomic Study of Edible Bivalve from Selected Division of Sarawak, Malaysia

    Directory of Open Access Journals (Sweden)

    M.K. Abu Hena

    2012-01-01

    Full Text Available The diversity of edible bivalve was conducted from August 2010 to July 2011 covering eight divisions i.e., Kuching, Sarikei, Sibu, Mukah, Bintulu, Miri, Limbang and Lawas of Sarawak, Malaysia. Samples were collected from native market and fishing village during the study period. All edible bivalves inhabit either in brackish or marine environment and comprised 19 species from 10 families namely Meretrix meretrix, M. lyrata, Paphia undulata, Circe scripta, Solen regularies, Solen lamarckii, Pharella acutidens, Amusium pleuronectes, Anadara granosa, Pholas orientalis, Gluconome virens, Placuna placenta, Crassotrea lugubris, Isognomon ephippium, Polymesoda erosa, P. bengalensis, P. expansa, Anadonta woodina and Pilsbryoconcha exilis. The diversity of edible bivalves was found highest in Kuching and Bintulu compared to other divisions studied in Sarawak. The bivalve species at Sarawak could have economic potentiality in terms of protein source, livelihoods of local tribes and economic value. Study suggests that if the high conservation and management of edible bivalve diversity could establish in the coastal and wetland area of Sarawak, a remarkable and vast economic return could achieve.

  20. Adrenoleukodystrophy manifesting as spinocerebellar degeneration

    Directory of Open Access Journals (Sweden)

    Mishra Sanjay

    2006-01-01

    Full Text Available X-linked adrenoleukodystrophy (XALD is an inherited disorder of peroxisomal metabolism. Atypical presentations have been occasionally reported in literature. However, extrapyramidal and cerebellar manifestations are distinctly rare. We report a patient of X-linked adrenoleukodystrophy with cranial and cervical dystonia and neurological presentation resembling spinocerebellar degeneration followed by a brief review of relevant literature.

  1. Preliminary estimates of growth parameters for three commercial bivalve species of Peru (Gari solida, Anlacomya ater and Semele solida)

    OpenAIRE

    Urban, H. J.

    1991-01-01

    The parameters of the von Bertalanffy growth equation were estimated, mainly from size-frequency data, for three commercially exploited Peruvian bivalves, Gari solida, Aulacomya ater and Semele solida, collected by divers from "Bahia de Independencia", Pisco, Peru from November 1986 to September 1987 and from January to September 1990. Some related information on the three bivalves in question are also presented.

  2. The influence of sediment, food and organic ligands on the uptake of copper by sediment-dwelling bivalves

    NARCIS (Netherlands)

    Absil, M.C.P.; Berntssen, M.; Gerringa, L.J.A.

    1996-01-01

    The sediment-dwelling bivalve Macoma balthica was exposed to dissolved copper ina flow-through system in long-term experiments. Unlike another sediment-dwelling bivalve, the suspension feeder Cerastoderma edule (cockle), M. balthica accumulated copper from the sediment, while the cockles did not. Wh

  3. Effect of reinforcement surface functionalization on the mechanical properties of nacre-like bulk lamellar composites processed by a hybrid conventional method

    International Nuclear Information System (INIS)

    Alumina platelet reinforced epoxy matrix composites with an architecture resembling to natural nacre were fabricated by a hybrid conventional method called Hot-press Assisted Slip Casting process (HASC). Correlation between processing parameters, platelet content, platelet orientation and mechanical property enhancement of the fabricated composites was examined. In order to investigate the effect of interfacial compatibility and bonding on the mechanical properties of the fabricated inorganic–organic composites, platelet surfaces were modified with both epoxy- and amino-functional silanes. As received and functionalized platelet surfaces were studied by X-Ray Photoelectron Spectroscopy (XPS) to confirm the success of surface modification. Fabricated bio-inspired bulk lamellar composite materials were characterized in terms of their microstructural architecture and mechanical properties. The results obtained indicated that HASC processed composites exhibit enhanced flexural strength, stiffness and hardness, as compared to neat epoxy and composites fabricated by simple mixing, as a result of their nacre-like architecture with well aligned platelets. It has been also observed that functionalization by both type of silanes improves interfacial adhesion between platelets and epoxy matrix resulting in further enhancement of the mechanical properties of bulk lamellar composites fabricated by HASC. - Highlights: ► Bulk lamellar inorganic–organic composites were fabricated by HASC process. ► Effect of platelet content and orientation on mechanical properties was examined. ► Interfacial adhesion was improved by surface treatment of platelets with silanes. ► Impact of interfacial bonding on mechanical properties of composites was revealed

  4. In situ method for measurements of community clearance rate on shallow water bivalve populations

    DEFF Research Database (Denmark)

    Hansen, Benni W.; Dolmer, Per; Vismann, Bent

    2011-01-01

    air lift connected to a SCUBA diver pressure tank generating a continuous and gentle water circulation. This ensures a complete mixture of suspended particles, and thereby, a maximum filtration by the bivalves. An in situ fluorometer was mounted to record plant pigment reduction due to mussel...... clearance in real-time. To calibrate the in situ fluorometer triplicate water samples were obtained initially in each of the bivalve filtration measurements. The water samples were filtrated, extracted, and later analyzed for plant pigment concentration on a laboratory spectrophotometer. The main conclusion......An open-top chamber was designed for measuring ambient community clearance rate on undisturbed bivalve populations in the field. The chamber was pressed 5-10 cm down in the sediment on the mussel bed. It holds approximately 30-40 cm water column equal to a volume of 43-77 L. It was provided with an...

  5. Labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013

    Directory of Open Access Journals (Sweden)

    Domenico Meloni

    2015-06-01

    Full Text Available The aim of the present survey was to investigate the correct enforcement of the Community rules on the labelling and marketing of bivalve and gastropod molluscs retailed in Sardinia, Italy between 2009 and 2013. A total of 1500 packages and labels for live bivalve and gastropod molluscs were considered. A total of 375 labels (25% presented non-compliance concerning the wrong trade name and additional wrong or missing information. The highest percentage of anomalous labels has been detected in small-scale retail shops (35% and open-air markets (25% compared with the big retailing chains (20%. The 5% of packages were not in compliance with the European Community rules on packaging of bivalve and gastropod molluscs. The high percentage of non-compliance with the European regulations on labelling results is a strong limitation for the consumers and highlights the need to improve the control system about labelling of seafood products.

  6. Dioxin-like chemicals in bivalves and sediment collected from around Australia

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, J.F.; Muller, R.; Goudkamp, K. [EnTox, The University of Queensland, Brisbane (AU)] (and others)

    2004-09-15

    The aquatic environment is a significant sink for persistent organic pollutants including dioxin-like chemicals. Besides continuous investigations into sources of higher chlorinated PCDD that have initially been found in soils, and later in dugong and sediments little is known about the levels of dioxin-like chemicals in Australia's aquatic environment. In 2002 the National Dioxin Program (NDP) was commissioned by the Department of Environment and Heritage, Australia. One focus of the NDP was to evaluate background levels of dioxin-like chemicals in Australia's environment. One component of the 'Environmental Levels' project aimed to identify dioxinlike chemicals in the aquatic environment including bivalves collected in both marine, estuarine and freshwater systems. Here we report results from the NDP aquatic study with a particular emphasis on the levels of dioxin-like chemicals in bivalves and sediments respectively in areas from where the bivalves were collected.

  7. Saturation-state sensitivity of marine bivalve larvae to ocean acidification

    Science.gov (United States)

    Waldbusser, George G.; Hales, Burke; Langdon, Chris J.; Haley, Brian A.; Schrader, Paul; Brunner, Elizabeth L.; Gray, Matthew W.; Miller, Cale A.; Gimenez, Iria

    2015-03-01

    Ocean acidification results in co-varying inorganic carbon system variables. Of these, an explicit focus on pH and organismal acid-base regulation has failed to distinguish the mechanism of failure in highly sensitive bivalve larvae. With unique chemical manipulations of seawater we show definitively that larval shell development and growth are dependent on seawater saturation state, and not on carbon dioxide partial pressure or pH. Although other physiological processes are affected by pH, mineral saturation state thresholds will be crossed decades to centuries ahead of pH thresholds owing to nonlinear changes in the carbonate system variables as carbon dioxide is added. Our findings were repeatable for two species of bivalve larvae could resolve discrepancies in experimental results, are consistent with a previous model of ocean acidification impacts due to rapid calcification in bivalve larvae, and suggest a fundamental ocean acidification bottleneck at early life-history for some marine keystone species.

  8. Characterization of the mantle transcriptome in bivalves: Pecten maximus, Mytilus edulis and Crassostrea gigas.

    Science.gov (United States)

    Yarra, Tejaswi; Gharbi, Karim; Blaxter, Mark; Peck, Lloyd S; Clark, Melody S

    2016-06-01

    The calcareous shells secreted by bivalve molluscs display diverse and species specific structural compositions, which indicates possible divergent biomineralization processes. Thus, studying multiple mollusc species will provide a more comprehensive understanding of shell formation. Here, the transcriptomes of the mantle tissues responsible for shell deposition were characterized in three commercially relevant bivalve species. Using high-throughput sequencing and bioinformatics tools, de novo transcriptome assemblies of mantle tissues were generated for the mussel Mytilus edulis, the oyster Crassostrea gigas and the scallop Pecten maximus. These transcriptomes were annotated, and contigs with similarity to proteins known to have shell formation roles in other species were identified. Comparison of the shell formation specific proteins in the three bivalves indicates the possibility of species specific shell proteins. PMID:27160853

  9. The shell matrix of the freshwater mussel Unio pictorum (Paleoheterodonta, Unionoida). Involvement of acidic polysaccharides from glycoproteins in nacre mineralization.

    Science.gov (United States)

    Marie, Benjamin; Luquet, Gilles; Pais De Barros, Jean-Paul; Guichard, Nathalie; Morel, Sylvain; Alcaraz, Gérard; Bollache, Loïc; Marin, Frédéric

    2007-06-01

    Among molluscs, the shell biomineralization process is controlled by a set of extracellular macromolecular components secreted by the calcifying mantle. In spite of several studies, these components are mainly known in bivalves from only few members of pteriomorph groups. In the present case, we investigated the biochemical properties of the aragonitic shell of the freshwater bivalve Unio pictorum (Paleoheterodonta, Unionoida). Analysis of the amino acid composition reveals a high amount of glycine, aspartate and alanine in the acid-soluble extract, whereas the acid-insoluble one is rich in alanine and glycine. Monosaccharidic analysis indicates that the insoluble matrix comprises a high amount of glucosamine. Furthermore, a high ratio of the carbohydrates of the soluble matrix is sulfated. Electrophoretic analysis of the acid-soluble matrix revealed discrete bands. Stains-All, Alcian Blue, periodic acid/Schiff and autoradiography with (45)Ca after electrophoretic separation revealed three major polyanionic calcium-binding glycoproteins, which exhibit an apparent molecular mass of 95, 50 and 29 kDa, respectively. Two-dimensional gel electrophoresis shows that these bands, provisionally named P95, P50 and P29, are composed of numerous isoforms, the majority of which have acidic isoelectric points. Chemical deglycosylation of the matrix with trifluoromethanesulfonic acid induces a drastic shift of both the apparent molecular mass and the isoelectric point of these matrix components. This treatment induces also a modification of the shape of CaCO(3) crystals grown in vitro and a loss of the calcium-binding ability of two of the main matrix proteins (P95 and P50). Our findings strongly suggest that post-translational modifications display important functions in mollusc shell calcification. PMID:17488282

  10. Morphometric Studies on Anodonta Anatine Bivalve Population from the Dognecea Lake

    Directory of Open Access Journals (Sweden)

    Marian Bura

    2011-10-01

    Full Text Available In the Dognecea Lake, near town Bocsa in Caras-Severin county a strong bivalve population has been discovered from the duck mussel specie (Anodonta anatina. Harvested individuals were transported to the Aquaculture laboratory where measurements and correct identification was made. This specie is considered endangered but in Banat area, especially in the Dognecea Lake it is well represented, having an ecological importance, but the bivalve can have an economical importance too, due to the high percentage of edible part of 56.5%.

  11. Unusual clinical manifestations of leptospirosis

    Directory of Open Access Journals (Sweden)

    Bal A

    2005-01-01

    Full Text Available Leptospirosis has protean clinical manifestations. The classical presentation of the disease is an acute biphasic febrile illness with or without jaundice. Unusual clinical manifestations may result from involvement of pulmonary, cardiovascular, neural, gastrointestinal, ocular and other systems. Immunological phenomena secondary to antigenic mimicry may also be an important component of many clinical features and may be responsible for reactive arthritis. Leptospirosis in early pregnancy may lead to fetal loss. There are a few reports of leptospirosis in HIV- infected individuals but no generalisation can be made due to paucity of data. It is important to bear in mind that leptospiral illness may be a significant component in cases of dual infections or in simultaneous infections with more than two pathogens.

  12. ORBITAL MANIFESTATIONS OF SINUS DISEASE

    Directory of Open Access Journals (Sweden)

    Jyothirmayi

    2015-01-01

    Full Text Available AIM : To study the orbital manifestations in patients with sinus disease. METHODS : Patients wit h paranasal sinus disease presenting to OPD at Government ENT Hospital, AMC, Visakhapatnam from January 2012 to June 2014 were screened for orbital manifestations. Out of these, thirteen patients with orbital disease were referred to GREH, AMC, Visakhapatn am and were thoroughly investigated and managed appropriately. RESULTS : Out of the 14 patients 4 were female and 10 were male. Age ranged from 19 years to 70 years. 5 had maxillary sinus disease (4 - carcinoma and 1 case of mucormycosis. Frontal sinus dis ease was seen in two patients, one fibrous dysplasia and one malignancy. Five patients had ethmoidal sinus disease of which three patients were found to have ethmoidal sinus tumour (Malignant melanoma, Squamous cell Carcinoma. More than two sinuses were i nvolved in 2 patients. CONCLUSIONS : Early screening of patients with sinus disease by an Ophthalmologist can help in preventing severe vision threatening orbital complications.

  13. Cardiopulmonary Manifestations of Ankylosing Spondylitis

    Directory of Open Access Journals (Sweden)

    Mahnaz Momeni

    2011-01-01

    Full Text Available Ankylosing spondylitis is a chronic inflammatory condition that usually affects young men. Cardiac dysfunction and pulmonary disease are well-known and commonly reported extra-articular manifestation, associated with ankylosing spondylitis (AS. AS has also been reported to be specifically associated with aortitis, aortic valve diseases, conduction disturbances, cardiomyopathy and ischemic heart disease. The pulmonary manifestations of the disease include fibrosis of the upper lobes, interstitial lung disease, ventilatory impairment due to chest wall restriction, sleep apnea, and spontaneous pneumothorax. They are many reports detailing pathophysiology, hypothesized mechanisms leading to these derangements, and estimated prevalence of such findings in the AS populations. At this time, there are no clear guidelines regarding a stepwise approach to screen these patients for cardiovascular and pulmonary complications.

  14. Breast manifestations of systemic diseases

    Directory of Open Access Journals (Sweden)

    Dilaveri CA

    2012-02-01

    Full Text Available Christina A Dilaveri, Maire Brid Mac Bride, Nicole P Sandhu, Lonzetta Neal, Karthik Ghosh, Dietlind L Wahner-RoedlerDivision of General Internal Medicine, Mayo Clinic, Rochester, MN, USAAbstract: Although much emphasis has been placed on the primary presentations of breast cancer, little focus has been placed on how systemic illnesses may affect the breast. In this article, we discuss systemic illnesses that can manifest in the breast. We summarize the clinical features, imaging, histopathology, and treatment recommendations for endocrine, vascular, systemic inflammatory, infectious, and hematologic diseases, as well as for the extramammary malignancies that can present in the breast. Despite the rarity of these manifestations of systemic disease, knowledge of these conditions is critical to the appropriate evaluation and treatment of patients presenting with breast symptoms.Keywords: breast, endocrine, hematologic, infectious, vascular

  15. Digestive manifestations of parathyroid disorders

    Institute of Scientific and Technical Information of China (English)

    Bassam Abboud; Ronald Daher; Joe Boujaoude

    2011-01-01

    The parathyroid glands are the main regulator of plasma calcium and have a direct influence on the digestive tract. Parathyroid disturbances often result in unknown long-standing symptoms. The main manifestation of hypoparathyroidism is steatorrhea due to a deficit in exocrine pancreas secretion. The association with celiac sprue may contribute to malabsorption. Hyperparathyroidism causes smooth-muscle atony, with upper and lower gastrointestinal symptoms such as nausea, heartburn and constipation. Hyperparathyroidism and peptic ulcer were strongly linked before the advent of proton pump inhibitors. Nowadays, this association remains likely only in the particular context of multiple endocrine neoplasia type 1/Zollinger-Ellison syndrome. In contrast to chronic pancreatitis, acute pancreatitis due to primary hyperparathyroidism is one of the most studied topics. The causative effect of high calcium level is confirmed and the distinction from secondary hyperparathyroidism is mandatory. The digestive manifestations of parathyroid malfunction are often overlooked and serum calcium level must be included in the routine workup for abdominal symptoms.

  16. Unusual manifestation of dengue fever

    OpenAIRE

    Chaudhary, Shyam Chand; Mohanty, D; Sonkar, S K; Gupta, Durgesh Kumar; Gupta, Abhinav

    2011-01-01

    Dengue fever is an important public health problem in India and has various serious manifestations, which if not identified and treated at appropriate time can lead to dire consequences. Quadriparesis during the course of dengue infection is quite unusual and rarely reported. The authors hereby report a case of acute motor quadriparesis due to Guillain–Barre syndrome during the course of dengue infection, who showed gradual response to conservative treatment.

  17. Peritoneal manifestations of parasitic infection.

    Science.gov (United States)

    Kim, So Yeon; Ha, Hyun Kwon

    2008-01-01

    The purpose of this study was to describe of peritoneal manifestations of parasitic infection at CT. A broad spectrum of CT findings can be seen in the peritoneal cavity, including a varying degree of omental or mesenteric infiltration, single or multiple peritoneal mass or nodule, and peritoneal thickening or stranding. Recognition of these findings are crucial for establish an early diagnosis and helps avoid unnecessary surgery. PMID:17924162

  18. Ocular manifestation in canine leishmaniasis

    OpenAIRE

    Ralić Marjan; Jovanović Milan

    2011-01-01

    This paper presents a case of ocular changes in leishmaniasis in a dog brought in for examination because of visible changes in the eyes. An ocular manifestation in leishmaniasis can be bilateral or unilateral. Changes most often occur on the conjunctive and the front segment of the eye, the cornea and iris. From 70 to 80% of dogs diseased with leishmaniasis exhibit frontal uveitis, and dry eye, keratoconjunctivitis sicca, is also a frequent finding. Based ...

  19. Parasitic Diseases With Cutaneous Manifestations.

    Science.gov (United States)

    Ash, Mark M; Phillips, Charles M

    2016-01-01

    Parasitic diseases result in a significant global health burden. While often thought to be isolated to returning travelers, parasitic diseases can also be acquired locally in the United States. Therefore, clinicians must be aware of the cutaneous manifestations of parasitic diseases to allow for prompt recognition, effective management, and subsequent mitigation of complications. This commentary also reviews pharmacologic treatment options for several common diseases. PMID:27621348

  20. Skin manifestations of child abuse

    OpenAIRE

    Ermertcan Aylin; Ertan Pelin

    2010-01-01

    Child abuse is a major public health problem all over the world. There are four major types of abuse: physical abuse, sexual abuse, emotional abuse and neglect. The most common manifestations of child abuse are cutaneous and their recognition; and differential diagnosis is of great importance. Clinicians, especially dermatologists, should be alert about the skin lesions of child abuse. In the diagnosis and management of child abuse, a multidisciplinary approach with ethical and legal procedur...

  1. 78 FR 11877 - Announcement of Requirements Gathering Meetings for the Electronic Manifest (e-Manifest) System

    Science.gov (United States)

    2013-02-20

    ... electronic manifest (``e-Manifest'') system to capture information regarding the shipment of hazardous waste...-Manifest will facilitate the electronic transmittal of manifests throughout the hazardous waste shipping... inefficiencies associated with the use of paper manifest forms (66 FR 28240). Although comments...

  2. [Neuropsychiatric manifestations ushering pernicious anemia].

    Science.gov (United States)

    Mrabet, S; Ellouze, F; Ellini, S; Mrad, M F

    2015-12-01

    Biermer disease or pernicious anemia is an autoimmune atrophic gastritis characterized by the lack of secretion of gastric intrinsic factor. This leads to an insufficient absorption of vitamin B12 in the ileum. Clinical manifestations are mainly hematologic. Neuropsychiatric manifestations are known but are less frequent especially early in the disease. Inaugural neuropsychiatric arrays are rare and various thus making diagnosis difficult. In this article, we report through two clinical cases different neuropsychiatric manifestations revealing pernicious anemia. Mrs. C.O., aged 56, presented after surgery for gallstones, an acute psychiatric array associated with gait disorders. She had no history of neurological or psychiatric problems. The psychiatric interview revealed delirious syndrome, depressive symptoms and anxiety. Neurological examination noted a flaccid paraplegia with peripheral neuropathic syndrome and myoclonus in the upper limbs. At the full blood count, a macrocytosis (VGM: 112.2fl) without anemia was found. The level of vitamin B12 in the blood was low. Cerebro-spinal MRI was suggestive of a neuro-Biermer and showed hyper signal in the cervical cord on T2-weighted sagittal section. In axial section, hyper signal appears at the posterior columns in the form of V. There were no brain abnormalities. A sensorimotor axonal polyneuropathy was diagnosed. The patient received vitamin B12 intramuscularly for ten days associated with neuroleptic treatment. Mrs. R.M., aged 40, was brought to the psychiatry consultation for acute behavioral disorders progressively worsening over a month. An anxiety syndrome, depressive syndrome and delirious syndrome were identified. Neurological examination showed a posterior cordonal syndrome with quadripyramidal syndrome. Full blood count showed a macrocytic anemia. Serum B12 level was collapsed. Cerebro-spinal MRI was normal. She received vitamin B12 with clinical and biological improvement. Features of pernicious anemia

  3. CYP1A-immunopositive proteins in bivalves identified as cytoskeletal and major vault proteins

    DEFF Research Database (Denmark)

    Grøsvik, Bjørn Einar; Jonsson, Henrik; Rodríguez-Ortega, Manuel J;

    2006-01-01

    To identify possible CYP1A-immunopositive proteins in bivalves, we used anti-fish CYP1A antibodies combined with one- and two-dimensional gel electrophoresis and mass spectrometry, and found that two of the main CYP1A-immunopositive proteins in digestive gland of Mytilus edulis, were cytoskeletal...

  4. 210Po, 40K activity concentrations in bivalves collected along the Southern Coastal from Spain

    International Nuclear Information System (INIS)

    The levels of 210Po and 40K were determined in several species of bivalves growing along the coast of the region of Andalusia (southern Spain) during 2005. A network sampling of 30 points was designed and the 5 species more consumed were selected, in order to obtain the base line (background) of these species. Once the bivalve samples were lyophilized, the natural radionuclides were measured by both alpha-particle spectrometry (210Po) and gamma spectrometry (40K), being 40K the only one radionuclide detected by gamma spectrometry. Several variables like type of water (Atlantic Ocean vs Mediterranean Sea), bivalve specie, percentage of water (dry weight/wet weight relation), and the geographical distribution have been studied in relation to activity concentrations of natural radionuclides. The values of the activity concentrations between the different species and the origin of waters (atlantics or mediterranean) were not statistically significant. The activity concentrations of 210Po varied between 85 ± 4 Bq kg-1 (d.w., dry weight) and 648 ± 22 Bq kg-1 (d.w.) (Average = 250 ± 121 Bq kg-1), while 40K activity concentrations ranged from 357 ± 28 to 817 ± 48 Bq kg-1 (d.w.) (Average = 522 ± 114 Bq kg-1). On the other hand, and due to the high consume rates of bivalves in the coastal populations, the dosimetric implications of the 210Po activity concentrations found in the study have been also evaluated. (author)

  5. Bivalve grazing, nutrient cycling and phytoplankton dynamics in an estuarine ecosystem.

    NARCIS (Netherlands)

    Prins, T.C.

    1996-01-01

    This thesis has considered the impact of the suspension feeding bivalve Mytilusedulis on nutrient cycling and phytoplankton in an estuarine ecosystem. The research was started within the framework of an extensive research project with the objective to evaluate the changes in the Oosterschelde ecosys

  6. Nutritional and reproductive strategies in a chemosymbiotic bivalve living in a tropical intertidal seagrass bed

    NARCIS (Netherlands)

    van der Geest, M.; Sall, A.A.; Ely, S.O.; Nauta, R.W.; van Gils, J.A.; Piersma, T.

    2014-01-01

    Sulphide-oxidizing endosymbiont-bearing bivalves often dominate the infauna of seagrass-covered sediments, where they control sulphide levels and contribute to carbon cycling by feeding on chemosynthetically fixed carbon and suspended particulate organic matter (SPOM). Previous studies from temperat

  7. Nutritional and reproductive strategies in a chemsoymbiotic bivalve living in a tropical intertidal seagrass bed

    NARCIS (Netherlands)

    van der Geest, Matthijs; Sall, Amadou Abderahmane; Ely, SIdi Ould; Nauta, Reindert W.; Gils, Jan A. van; Piersma, Theunis

    2014-01-01

    Sulphide-oxidizing endosymbiont-bearing bivalves often dominate the infauna of seagrass-covered sediments, where they control sulphide levels and contribute to carbon cycling by feeding on chemosynthetically fixed carbon and suspended particulate organic matter (SPOM). Previous studies from temperat

  8. Wood-Boring Bivalves (Mollusca: Teredinidae, Pholadidae) of Pacific coast of Colombia

    International Nuclear Information System (INIS)

    Twelve species of wood-boring bivalves, ten of the family Teredinidae and two of family Pholadidae were collected in mangroves at 6 locations of the Pacific coast of Colombia. This paper presents a brief description of these species, including size, ecological notes and geographical distribution.

  9. Freshwater bivalve mollusca (unionidae, sphaeriidae, corbiculidae) of the Savannah River Plant, South Carolina

    International Nuclear Information System (INIS)

    A guide to freshwater bivalve molluscs found at the Savannah River Plant is presented. A dichotomous taxonomic key is provided to common forms and to unreported species whose geographic distributions include nearby localities. Discussions of ecology, life history, larval hosts, and other pertinent information is provided

  10. Novas ocorrências de gastrópodes e bivalves marinhos no Brasil (Mollusca

    Directory of Open Access Journals (Sweden)

    Absalão Ricardo Silva

    2003-01-01

    Full Text Available The gastropods Costaclis egregia (Dall, 1889, Thaleia nisonis (Dall, 1889, Tjaernoeia michaeli Engl, 2001 and the bivalves Bathyarca sp., Myonera aff. ruginosa (Jeffreys, 1882 are recorded for the first time in Brazilian waters. This paper presents a brief description of these species and also include ilustrations.

  11. Uptake of contaminants of emerging concern by the bivalves Anodonta californiensis and Corbicula fluminea.

    Science.gov (United States)

    Ismail, Niveen S; Müller, Claudia E; Morgan, Rachel R; Luthy, Richard G

    2014-08-19

    Uptake of seven contaminants regularly detected in surface waters and spanning a range of hydrophobicities (log D(ow) -1 to 5) was studied for two species of freshwater bivalves, the native mussel Anodonta californiensis and the invasive clam Corbicula fluminea. Batch systems were utilized to determine compound partitioning, and flow-through systems, comparable to environmental conditions in effluent dominated surface waters, were used to determine uptake and depuration kinetics. Uptake of compounds was independent of bivalve type. Log bioconcentration factor (BCF) values were correlated with log D(ow) for nonionized compounds with the highest BCF value obtained for triclocarban (TCC). TCC concentrations were reduced in the water column due to bivalve activity. Anionic compounds with low D(ow) values, i.e., clofibric acid and ibuprofen, were not removed from water, while the organic cation propranolol showed biouptake similar to that of TCC. Batch experiments supported compound uptake patterns observed in flow-through experiments. Contaminant removal from water was observed through accumulation in tissue or settling as excreted pseudofeces or feces. The outcomes of this study indicate the potential utility of bivalve augmentation to improve water quality by removing hydrophobic trace organic compounds found in natural systems. PMID:25017714

  12. Modiolarca lateralis (Pteryomorphia: Mytilidae: bivalve associated to six species of ascidians from Bocas del Toro, Panama

    Directory of Open Access Journals (Sweden)

    Juan I Cañete

    2013-11-01

    Full Text Available We describe the presence of the bivalve Modiolarca lateralis (Say, 1822 in six tropical ascidians Ascidia curvata, A. sydneiensis, A. panamensis, A. interrupta, Herdmania pallida and Polycarpa spongiabilis collected at depths of 1-3 m on coral reefs, mangrove roots and dock supports in Almirante Bay, Bocas del Toro, Panama (9°18'N, 82°13'W during June-July 2011. Bivalve prevalence varied between 9-30% across species, but was mainly associated with A. panamensis, P. spongiabilis and A. interrupta. Prevalence seems to be influenced by tunic thickness rather than by the ascidian size. Bivalves varied in size (0.6-11 mm shell length, with the smallest individual found in A. sydneiensis. There were only one or two bivalves per ascidians, although a maximum of 18 was found in one A. panamensis. M. lateralis seems to behave similarly to its temperate counterparts: it has a variety of hosts, occurs mainly in the anterior region of the ascidians, and has a variable abundance per host.

  13. Accumulation, Toxicity And Elimination Of 60Co In Some Aquatic Bivalves

    International Nuclear Information System (INIS)

    The present study was undertaken to evaluate the importance of some common bivalve oysters namely Caelatura teretiusculua and Caelatura companyoi as new radiobioindicators for 60Co in Egyptian aquatic environment.The uptake and accumulation of 60Co in water were followed for four weeks to evaluate the following:1-Maximum uptake as concentration factor values.2-The rate of survival of bivalves at different activity levels of 60Co to estimate its toxic effect.3-The lethal dose (LD50) of 60Co.4-The effect of ph of 60Co polluted water on survival of biota.5-The competitive effects of Zn+2 and Fe+3 with 60Co on the uptake and accumulation.6-The effect of biota weight on the uptake of 60Co.7-Elimination of the accumulated 60Co by such biota in water and in 10-4M ethylene diamine tetra acetic acid (EDTA) as chelating agent that enhance the bivalve to release the accumulated radioisotope.The results showed that 60Co was highly taken up by the investigated biota with high concentration factor values and that EDTA enhanced the decontamination of 60Co than water. It could be concluded that the investigated bivalves can be used as good radiobioindicators for pollution of water with 60Co.

  14. Cardiac manifestations in systemic sclerosis

    Institute of Scientific and Technical Information of China (English)

    Sevdalina; Lambova

    2014-01-01

    Primary cardiac involvement, which develops as a direct consequence of systemic sclerosis(SSc), may manifest as myocardial damage, fibrosis of the conduction system, pericardial and, less frequently, as valvular disease. In addition, cardiac complications in SSc may develop as a secondary phenomenon due to pulmonary arterial hypertension and kidney pathology. The prevalence of primary cardiac involvement in SSc is variable and difficult to determine because of the diversity of cardiac manifestations, the presence of subclinical periods, the type of diagnostic tools applied, and the diversity of patient populations. When clinically manifested, cardiac involvement is thought to be an important prognostic factor. Profound microvascular disease is a pathognomonic feature of SSc, as both vasospasm and structural alterations are present. Such alterations are thought to predict macrovascular atherosclerosis over time. There are contradictory reports regarding the prevalence of atherosclerosis in SSc. According to some authors, the prevalence of atherosclerosis of the large epicardial coronary arteries is similar to that of the general population, in contrast with other rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus. However, the level of inflammation in SSc is inferior. Thus, the atherosclerotic process may not be as aggressive and not easily detectable in smaller studies. Echocardiography(especially tissue Doppler imaging), single-photon emission computed tomography, magnetic resonance imaging and cardiac computed tomography are sensitive techniques for earlier detection of both structural and functional scleroderma-related cardiac pathologies. Screening for subclinical cardiac involvement via modern, sensitive tools provides an opportunity for early diagnosis and treatment, which is of crucial importance for a positive outcome.

  15. Liver manifestations of cystic fibrosis

    International Nuclear Information System (INIS)

    Chronic liver disease is one of the major complications of cystic fibrosis (CF). Significant liver disease is seen in 13-25% of children with CF. Improved life expectancy and prolonged follow-up have favored better characterization of the hepatic manifestations of CF and allowed direct observation of an increasing number of liver-related events. Liver disease typically develops in the first decade of life, with the incidence dropping rapidly after the age of 10 years. The wide spectrum of liver disease ranging from asymptomatic gallbladder abnormalities to biliary cirrhosis will be reviewed in this article

  16. Neurological manifestation of colonic adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Uzair Chaudhary

    2012-04-01

    Full Text Available Paraneoplastic neurologic disorders are extremely rare in cancer patients and are most commonly associated with certain tumors, such as ovarian cancer, small cell lung cancer, and breast cancer. We report here a paraneoplastic neurological syndrome in a 53-year-old man with colonic adenocarcinoma with a solitary liver metastasis. His paraneoplastic syndrome was successfully treated by methylprednisolone and primary oncologic therapies including neoadjuvant chemotherapy and definitive surgery. This is also the first documented case of simultaneous manifestation of a sensory neuropathy and limbic encephalitis with colon cancer.

  17. Depth-related gradients in community structure and relatedness of bivalves and isopods in the Southern Ocean

    Science.gov (United States)

    Brandt, Angelika; Linse, Katrin; Ellingsen, Kari E.; Somerfield, Paul J.

    2016-05-01

    Despite increased research over the last decade, diversity patterns in Antarctic deep-sea benthic taxa and their driving forces are only marginally known. Depth-related patterns of diversity and distribution of isopods and bivalves collected in the Atlantic sector of the Southern Ocean are analysed. The data, sampled by epibenthic sledge at 40 deep-sea stations from the upper continental slope to the hadal zone (774-6348 m) over a wide area of the Southern Ocean, comprises 619 species of isopods and 81 species of bivalves. There were more species of isopods than bivalves in all samples, and species per station varied from 2 to 85 for isopods and from 0 to 18 for bivalves. Most species were rare, with 72% of isopod species restricted to one or two stations, and 45% of bivalves. Among less-rare species bivalves tended to have wider distributions than isopods. The species richness of isopods varied with depth, showing a weak unimodal curve with a peak at 2000-4000 m, while the richness of bivalves did not. Multivariate analyses indicate that there are two main assemblages in the Southern Ocean, one shallow and one deep. These overlap over a large depth-range (2000-4000 m). Comparing analyses based on the Sørensen resemblance measure and Γ+ (incorporating relatedness among species) indicates that rare species tend to have other closely related species within the same depth band. Analysis of relatedness among species indicates that the taxonomic variety of bivalves tends to decline at depth, whereas that of isopods is maintained. This, it is speculated, may indicate that the available energy at depth is insufficient to maintain a range of bivalve life-history strategies.

  18. An overview of chemosynthetic symbioses in bivalves from the North Atlantic and Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    S. Duperron

    2013-05-01

    Full Text Available Deep-sea bivalves found at hydrothermal vents, cold seeps and organic falls are sustained by chemosynthetic bacteria that ensure part or all of their carbon nutrition. These symbioses are of prime importance for the functioning of the ecosystems. Similar symbioses occur in other bivalve species living in shallow and coastal reduced habitats worldwide. In recent years, several deep-sea species have been investigated from continental margins around Europe, West Africa, eastern Americas, the Gulf of Mexico, and from hydrothermal vents on the Mid-Atlantic Ridge. In parallel, numerous, more easily accessible shallow marine species have been studied. Herein we provide a summary of the current knowledge available on chemosymbiotic bivalves in the area ranging west-to-east from the Gulf of Mexico to the Sea of Marmara, and north-to-south from the Arctic to the Gulf of Guinea. Characteristics of symbioses in 53 species from the area are summarized for each of the five bivalve families documented to harbor chemosynthetic symbionts (Mytilidae, Vesicomyidae, Solemyidae, Thyasiridae and Lucinidae. Comparisons are made between the families, with special emphasis on ecology, life cycle, and connectivity. Chemosynthetic symbioses are a major adaptation to ecosystems and habitats exposed to reducing conditions. However, relatively little is known regarding their diversity and functioning, apart from a few "model species" on which effort has focused over the last 30 yr. In the context of increasing concern about biodiversity and ecosystems, and increasing anthropogenic pressure on oceans, we advocate a better assessment of the diversity of bivalve symbioses in order to evaluate the capacities of these remarkable ecological and evolutionary units to withstand environmental change.

  19. The use of bivalves as rapid, real-time indicators of aquatic pollution

    International Nuclear Information System (INIS)

    The ability of bivalves to filter large volumes of water on a daily basis, combined with the relatively high permeability of their cell membranes, make them valuable organisms to use in the contemporary detection of pollution. Bivalves are well known to respond to chemical contaminants by isolating their soft tissues from the aquatic medium by valve closure. The sensory acuity (via specialized sensory regions including the osphradium) and associated repertoire of this behavioral response can be employed to assess subtle effects exerted by chemical contaminants, such as complex effluents, that may ultimately influence the survival of these organisms. As hazard assessment tools, behavioral studies reflect sublethal toxicity and often yield a highly sensitive estimate of the lowest observable effect concentration (LOEC). Moreover, valve movement behavior has been identified as one of the more sensitive biological early warning measures to a variety of aquatic contaminants, in comparison with those used in other aquatic animal phyla. Therefore, the valve movement behavior of both freshwater (Hyridella depressa, Velesunio angasi and V. ambiguus) and marine (Mytilus edulis) bivalves was continuously monitored, using an on-line computer based data acquisition system, during exposure to either trace metals (e.g. Cu, Cd, Mn and U) or complex effluents (ie treated sewage effluent and acid leachate derived from contaminated Sydney Harbour sediments), in the context of using the valve movement behavior of the bivalve species to indicate the biological significance of exposure to the above-mentioned pollutants. The results indicate that several components of the valve movement behavior of each bivalve provide quantifiable and ecologically interpretable sub-lethal endpoints for the rapid and sensitive evaluation of waters containing either complex effluents or elevated levels of trace metals

  20. First records of Freshwater Bivalves of Ilha Grande National Park, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Flávio Henrique Ragonha

    2014-03-01

    Full Text Available The Ilha Grande National Park, Paraná, Brazil, is located in the Upper Paraná River and has characteristics typical of a floodplains. This protected area includes lagoons connected and disconnected to the Paraná River, although the latter also connect during periods of high water level, thus composing a heterogeneous group of lacustrine environments. The enormous potential the flora and fauna diversities are still little known to the region, as can be seen through benthic invertebrates, inclunding bivalves mollusks. The granulometric composition of these floodplain lagoons was formed mainly by mud and very fine sand. Furthermore, organic matter composition was predominantly of fine particulate. The other abiotic factors differed from lagoons located within the island of the park to those located in the left margin of Paraná River. The results demonstrated the importance of abiotic factors such as the physical composition of granulometric texture, organic matter and macrophyte banks, to the establishment of bivalves in these floodplain lagoons. We recorded bivalves of Pisidium (native, Diplodon (native, and Corbicula (invasive. The highest values of Diplodon sp. density were observed at São João/C lake, for Pisidium sterkianum (Pilsbry, 1897 at São João/M lake, and to Jatobá/C lagoon with high density of invasive species Corbicula fluminea (Müller, 1774. This study to obtain conduct the first records of freshwater bivalves in floodplains lagoon in the Ilha Grande National Park, and provides contributions to better understanding the ecology of these mollusks. The recording of native species in the region of Upper Paraná River floodplain after a lomg period without new records, demonstrated the importance of protecting the lagoons of the Ilha Grande National Park as they can be a possible refuge to some species of native freshwater bivalves.

  1. Cutaneous manifestations of inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Al Roujayee Abdulaziz

    2007-01-01

    Full Text Available Inflammatory bowel disease (IBD has many extraintestinal manifestations, and skin lesions are one of the most frequently described extraintestinal findings. Reports indicate an incidence of cutaneous manifestations ranging from 2 to 34%, Cutaneous manifestations are usually related to the activity of the bowel disease but may have an independent course. In this review we aim to address the various cutaneous manifestations associated with IBD, their impact on the disease course, and the treatment options available.

  2. Cutaneous manifestations of internal malignancy

    Directory of Open Access Journals (Sweden)

    A Ayyamperumal

    2012-01-01

    Full Text Available Background: Many malignancies affecting the internal organs display cutaneous manifestations which may be either specific (tumor metastases or nonspecific lesions. Aims: The study is aimed at determining the frequency and significance of cutaneous manifestations among patients with internal malignancy. Materials and Methods: 750 cases of proven internal malignancy, who attended a cancer chemotherapy center in South India, were studied. Specific infiltrates were confirmed by histopathology, fine needle aspiration cytology (FNAC and marker studies. Results: Out of the 750 patients with internal malignancy, skin changes were seen in a total of 52 (6.93% patients. Conclusion: Cutaneous metastases (specific lesions were seen in 20 patients (2.66%: contiguous in 6 (0.8%, and non-contiguous in 14 (1.86%. Nonspecific skin changes were seen in 32 patients (4.26%. None of our patients presented with more than one type of skin lesions. Herpes zoster was the most common nonspecific lesion noticed in our patients, followed by generalized pruritus, multiple eruptive seborrheic keratoses, bullous disorder, erythroderma, flushing, purpura, pyoderma gangrenosum, insect bite allergy and lichenoid dermatitis.

  3. Atypical Manifestation of Vestibular Schwannoma

    Directory of Open Access Journals (Sweden)

    Webster, Guilherme

    2013-09-01

    Full Text Available Introduction: Vestibular schwannoma (also known as acoustic neuroma is a benign tumor whose cells are derived from Schwann sheaths, which commonly occurs from the vestibular portion of the eighth cranial nerve. Furthermore, vestibular schwannomas account for ∼8% of intracranial tumors in adults and 80 to 90% of tumors of the cerebellopontine angle. Its symptoms are varied, but what stands out most is a unilateral sensorineural hearing loss, with a low index of speech recognition. Objective: Describe an atypical manifestation of vestibular schwannoma. Case Report: The 46-year-old woman had vertigo and binaural hearing loss and fullness, with ear, nose, and throat examination suggestive of cochlear injury. After 6 months, the patient developed worsening of symptoms and onset of right unilateral tinnitus. In further exams the signs of cochlear damage remained, except for the vestibular test (hyporeflexia. Magnetic resonance imaging showed an expansive lesion in the right cerebellopontine angle. Discussion: This report warns about the atypical manifestations of vestibular schwannoma, which must always be remembered in investigating and diagnosing hearing loss.

  4. Oral manifestations of acute leukaemia

    Directory of Open Access Journals (Sweden)

    Ivanović Mirjana

    2011-01-01

    Full Text Available Acute leukaemia is the most common form of chilhood cancer. The aim of this paper was to underline the importance of oral manifestations in children with acute leukaemia. The disease and its treatment can directly or indirectly affect oral health. Oral manifestations are gingival inflammation and enlargement. Leukaemic cells are capable of infiltrating the gingiva and the deeper periodontal tissues which leads to ulceration and infection of oral tissues. Gingival bleeding is a common sign in patients with leukaemia. Symptoms include local lymphadenopathy, mucous membrane Petechiae and ecchymoses. Cytotoxic drugs have direct effects like mucositis, involving atrophy, desquamation and ulceration of the mucosa, with increasing the risk for local and systemic infections. Leukaemia can directly influence dental care and dental treatment, while oral lesions may have life-threatening consequences. Knowledge and skills among dentists may also not be adequate to treat children with acute leukaemia. It is therefore imperative that all stomatologists be aware of dental problems that occur in leukaemia in order to be able to effectively carry out appropriate measures to mitigate these problems.

  5. Streptococcus suis infection: Clinical manifestations

    Directory of Open Access Journals (Sweden)

    Dragojlović Julijana

    2005-01-01

    Full Text Available Introduction Streptococcus suis is a bacterium causing a disease in pigs and rarely in humans. This zoonosis is mostly found as a sporadic disease in individuals that were in contact with the affected or infected pigs: farmers, veterinarians and workers engaged in fresh pork processing. It is assumed that the bacterium enters the body through a cut abrasion in the skin. Initially, the condition resembles a flu, followed by signs of bacteriemia and sepsis. The most frequent clinical manifestation of Streptococcus suis infection is meningitis, leading to hearing loss in over 75% of patients, and subsequent arthritis, endophtalmitis, endocarditis and pneumonia. Toxic shock syndrome with hemorhagic manifestations rarely develops. Material and methods This study included five male patients aged 22 to 63 years treated in the Intensive Care Unit of the Institute of Infectious and Tropical Diseases in Belgrade, due to Streptococcus suis infection. The aim of this study was to point to the existence of this bacteria in our environment, to describe clinical manifestations of the disease and to point out the importance of its prevention. Results All patients had epidemiological evidence of being in contact with pork meat. There were no data about diseased pigs. The estimated incubation period was 4 to 8 days. All patients had meningeal signs. Clinical symptoms included shivering, fever, vomiting, headache, malaise, vertigo and tinitus. Three patients presented with alerterd level of awareness. Four patients developed very severe bilateral hearing impairemnt, whereas one endophtalmtis and one developed endocarditis. The cerebrospinal fluid (CSF was opalescent in four patients, and only one patient presented with clear CSF. CSF examination showed typical changes characeteristic for bacterial meningitis. Streptoccocus suis was isolated in CSF in all patients, and in one patient the bacteria was isolated in blood as well. All patients underwent treatment with

  6. Radiological manifestations of rheumatoid arthritis

    International Nuclear Information System (INIS)

    Rheumatoid arthritis preferrably becomes manifest at the synovial joints of the limbs, especially at the small joints of the hands and feet, at bursae and synovial sheathes. The pathologic lesions are less frequently found at cartilaginous joints or entheses. The lesions very often are symmetrically distributed and are characterized by the following: 1. A periarticular, spindle-shaped opacity with a density similar to soft-tissue, induced by an inflammatory hypertrophy of the synovia, a serosynovitis, or an edematous impregnation of the periarticular tissue. 2. A juxta-articular osteoporosis, most probably caused by a neighbouring synovialitis accompanied by hyperemia. 3. A diffuse joint cavity narrowing due to a destruction of the articular cartilage by the pannus, a fibrovascular resorptive tissue. 4. Central as well as marginal erosions, caused by destruction of ossous material by the pannus. 5. Subchondral signal cysts, likewise unduced by the pannus. (Orig./AJ)

  7. [Purpura: primary systemic amyloidosis manifestation].

    Science.gov (United States)

    Lestre, Sara; Gonçalves, Andreia; João, Alexandre; Ferreira, Ana; Apetato, Margarida

    2009-01-01

    Primary Systemic Amyloidosis (AL) is the most frequent form of systemic amyloidosis and its morbilility is associated with immunoglobulin light chains deposition in vital organs. The mucocutaneous manifestations occur in about 30-40% of the cases and are important in diagnostic suspicion, once they appear in early stages of disease. We report a 71-years-old female patient, with disseminated purpura and cutaneous fragility with 6 months of evolution, accompanied by recent complaints of dysphagy. The first laboratory evaluation didn't show any alterations. The histological and immunohistochemical study of subcutaneous abdominal fat and skin biopsy showed lambda type amyloid protein. In the systemic work-up, we highlight a proteinúria > 1g/24h with Bence Jones proteins and the presence of monoclonal immunoglobulin light chain (lambda type) in serum immunoelectrophoresis. With the diagnosis of primary systemic amyloidosis, treatment with prednisolone and melphalan was started. PMID:19686633

  8. Atypical manifestations of early syphilis

    Directory of Open Access Journals (Sweden)

    Koranne R

    1990-01-01

    Full Text Available A study of 36 untreated patients with early syphilis revealed atypical variations namely; long incubation period of 101 days in I patient, more than 3 chancres in 1, undermined margin of the chancre along with tenderness in 1 and moderate to severe tenderness of the ulcers in 2 cases. In 3 patients there was no indurations of the ulcers. Three patients with primary syphilis had unilateral lymphadenitis, and in I case the lymph nodes were not only tender but showed tendency towardsmatingawell. Insecondarysyphilis, 11 out of 16 patients having condylomata lata had no other muco-cutaneous lesions. Concomitant presence of other venereal disease to account for the atypical manifestations was discounted- by appropriate laboratory tests, response to therapeutic agents and follow up.

  9. Polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons in a one-off global survey of bivalves

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Strand, Jakob; Christensen, Jan H.;

    2010-01-01

    During the Danish Galathea 3 expedition, bivalve samples were collected at the Faroe Islands, Greenland, Ghana, South Africa, Australia, Solomon Islands, New Zealand, Chile, US Virgin Islands, Boston, Newfoundland and Shetland Islands and analysed for organochlorines and PAHs. Concentration...

  10. The presence of putative sulphur-oxidizing bacteria colonizing the periostracal secretion in the endosymbiont-bearing bivalve Loripes lucinalis

    OpenAIRE

    Jonhson, M.A.; Fernandez, C

    2001-01-01

    Loripes lucinalis. a small bivalve belonging to the Lucinacea superfamily living in reducing coastal sediments, possesses chemoautotrophic sulphur-oxidizing bacteria in its gill. Here, a population of putative sulphur-oxidizing bacteria is described colonizing the bivalve's inner periostracal secretion. The bacteria, were particularly abundant in the vicinity of the anterior and posterior inhalant syphons. Most of the bacteria observed were oval to rod-shaped and measured 3.9 +/- 1.2 mum on a...

  11. Proteomic Profiling of Cytosolic Glutathione Transferases from Three Bivalve Species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea

    Directory of Open Access Journals (Sweden)

    José Carlos Martins

    2014-01-01

    Full Text Available Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs, in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST were surveyed in three bivalves with different habitats and life strategies: Corbicula fluminea, Anodonta cygnea and Mytilus galloprovincialis. GSTs were purified by glutathione-agarose affinity chromatography, and the collection of expressed cGST classes of each bivalve were identified using a proteomic approach. All the purified extracts were also characterized kinetically. Results reveal variations in cGST subunits collection (diversity and properties between the three tested bivalves. Using proteomics, four pi-class and two sigma-class GST subunits were identified in M. galloprovincialis. C. fluminea also yielded four pi-class and one sigma-class GST subunits. For A. cygnea, two mu-class and one pi-class GST subunits were identified, these being the first record of GSTs from these freshwater mussels. The affinity purified extracts also show differences regarding enzymatic behavior among species. The variations found in cGST collection and kinetics might justify diverse selective advantages for each bivalve organism.

  12. Proteomic profiling of cytosolic glutathione transferases from three bivalve species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea.

    Science.gov (United States)

    Martins, José Carlos; Campos, Alexandre; Osório, Hugo; da Fonseca, Rute; Vasconcelos, Vítor

    2014-01-01

    Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs), in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST) were surveyed in three bivalves with different habitats and life strategies: Corbicula fluminea, Anodonta cygnea and Mytilus galloprovincialis. GSTs were purified by glutathione-agarose affinity chromatography, and the collection of expressed cGST classes of each bivalve were identified using a proteomic approach. All the purified extracts were also characterized kinetically. Results reveal variations in cGST subunits collection (diversity and properties) between the three tested bivalves. Using proteomics, four pi-class and two sigma-class GST subunits were identified in M. galloprovincialis. C. fluminea also yielded four pi-class and one sigma-class GST subunits. For A. cygnea, two mu-class and one pi-class GST subunits were identified, these being the first record of GSTs from these freshwater mussels. The affinity purified extracts also show differences regarding enzymatic behavior among species. The variations found in cGST collection and kinetics might justify diverse selective advantages for each bivalve organism. PMID:24473139

  13. Studies on filtration rate in four species of suspension feeding bivalves

    Institute of Scientific and Technical Information of China (English)

    林元烧; 罗文新; 曹文清; 郭东晖; 郑爱榕; 黄长江

    2002-01-01

    The filtration rates of four kinds of bivalves that were cultivated dominantly around Xiamen sea area were measured by using a laboratory flowing system. The experimental results were shown below: (1) Filtration rates were measured in the range of 54~74.8 ml/ (g@min) among the four bivalves, sequencing descently Saccostrea cucullata > Sinonovacula constricta > Mytilus viridis > Ruditapes philippinarum. (2) The relationship between filtration rates on individual size showed a negative exponential function (FR = aWb, FR' = aWb-1), with b - 1 = - 0.435 6 and - 0.392. (3) Filtration rates on Skeletonema costatum were much higher than on Alexandrium tamarensis and Scrippsilla trochoidea inS. Cucullata and R. Philippinarum. (4) FR'on algal densities was also shown a negative function(FR' = aDb-1), with b-1 =-0.143 and-0.215 2 in S.cucullata and R.philippinarum, respectively.

  14. Bio-accumulation kinetics of radioruthenium in marine bivalves-laboratory study

    International Nuclear Information System (INIS)

    Bio-accumulation in marine organisms is a basic and important interaction for the retention and migration of pollutants such as heavy metals and radioactive nuclides in marine environment. Because of their high ability to bioconcentration trace metals and organic compounds, bivalves have been widely applied for monitoring the status of and temporal changes in the trance contaminants, i.e., the Mussel Watch Project of the USA. While their response to chemical change in their surroundings may be detectable within a matter of days, depending on the species and on the contaminants, therefore, bio-accumulation kinetics of pollutants in marine life body is important. In the present paper, three kinds of marine bivalves (wild Saccostrea cucullata, aquacultured Perna viridis and Pinctada martens), collected from Daya Bay, the South China Sea, where the first nuclear power station of China has been running from 1994, were chose to investigate the bio-accumulation of radioruthenium from natural seawater of Daya Bay (pH 8.20, 35 per thousand salinity) under laboratory conditions. Before experiment, the individual bivalve was acclimated for 2 days and then thoroughly washed with seawater to remove surface-adsorbed or/and surface-attached substances which could be an important source of the uptake of particle-reactive radioruthenium. After each interval of experiment, 5 individuals of each kinds of bivalves were sampled, executed, and dissected. The soft tissue was dried, ashed and nitrated and the shell was dried and powdered. The correspondence activity was determined by a γ-ray spectrometer (EG and G ORTEC ADCAM-2000, P-type, relative efficiency 35%). Bio-concentration factor is defined by BCF (mL/g)=103Ru Activity in tissue of bivalves (Bq/g-fresh)/103Ru Activity in seawater (Bq/ml). The plots of BCF of ruthenium in the tissues of bivalves are shown as a function of time The results clearly show that BCF increase sharply with time from beginning to 6 days and approach a

  15. Interactive effects of metal contamination and pathogenic organisms on the marine bivalve Cerastoderma edule

    International Nuclear Information System (INIS)

    The present study evaluated the interactive effects of cadmium contamination and pathogenic organisms (trematodes Himasthla elongata and bacteria Vibrio tapetis) singularly and in combination during 7 days on the bivalve Cerastoderma edule. Some defense-related activities were analyzed such as genetic expression, metallothionein and immune responses. Trematode metacercarial infection, similar whatever the treatment, induced the strongest responses of immune parameters. Particularly, the interaction between cadmium and parasite exposures induced unusual responses on gene expression and immune responses. No effect of bacterial challenge appeared on bivalve responses, nevertheless a strong mortality of V. tapetis infected cockles occured between 7 and 14 days. Cadmium bioaccumulation was significantly modulated by both pathogenic organisms. Furthermore, an antagonistic effect of trematodes and bacteria was shown on metal bioaccumulation of co-infected cockles. These results highlighted the importance of considering the multiplicity of perturbation sources in coastal ecosystems to assess the health status of organisms.

  16. Cytotoxicity assessment of antibiofouling compounds and by-products in marine bivalve cell cultures.

    Science.gov (United States)

    Domart-Coulon, I; Auzoux-Bordenave, S; Doumenc, D; Khalanski, M

    2000-06-01

    Short-term primary cell cultures were derived from adult marine bivalve tissues: the heart of oyster Crassostrea gigas and the gill of clam Ruditapes decussatus. These cultures were used as experimental in vitro models to assess the acute cytotoxicity of an organic molluscicide, Mexel-432, used in antibiofouling treatments in industrial cooling water systems. A microplate cell viability assay, based on the enzymatic reduction of tetrazolium dye (MTT) in living bivalve cells, was adapted to test the cytotoxicity of this compound: in both in vitro models, toxicity thresholds of Mexel-432 were compared to those determined in vivo with classic acute toxicity tests. The clam gill cell model was also used to assess the cytotoxicity of by-products of chlorination, a major strategy of biofouling control in the marine environment. The applications and limits of these new in vitro models for monitoring aquatic pollutants were discussed, in reference with the standardized Microtox test. PMID:10806375

  17. Trace metals in water, sediment and bivalves of a tropical estuary, west coast of India.

    Science.gov (United States)

    Parvez Al-Usmani, S M; Jagtap, T G; Patil, D N

    2015-10-15

    Trace metal pollution was studied in water, sediment and three selected bivalves in Mandovi and Chapora estuaries of Goa. The trace metal in water and sediment of Mandovi was higher than in Chapora. The concentration in the tissues was in the range of 1205.2-2506.7 ppm for Paphia malabarica, 1906.2-2802.6 ppm for Perna viridis and 778.7-1607.5 ppm for Saccostrea cucullata in Mandovi estuary. Tha values for Chapora were 199.4-625.8 ppm for P. malabarica, 812.6-1220.2 for P. viridis and 392.5-418.6 ppm for S. cucullata. The anthropogenic input of metal in Mandovi estuary appears to be mainly responsible for the high accumulation of trace metals. These bivalves have potential to serve as indicator for metal contamination in seafood of Goa. PMID:26228069

  18. Identification of lysozyme activity from two edible bivalves - Perna viridis (Linnaeus) and Meretrix casta (Chemnitz)

    Digital Repository Service at National Institute of Oceanography (India)

    Sharma, S.; Tanu; Chatterji, A.

    Pertanika J. Trop. Agric. Sci. 32(1): 85 - 90 (2009) ISSN: 1511-3701 ©Universiti Putra Malaysia Press Received: 20 May 2008 Accepted: 8 October 2008 * Corresponding Author Identification of Lysozyme Activity from Two Edible Bivalves - Perna viridis... the lysozyme from the whole body extracts of two edible and commercially important marine PDF compression, OCR, web optimization using a watermarked evaluation copy of CVISION PDFCompressor 86 Pertanika J. Trop. Agric. Sci. Vol. 32(1) 2009 Sumita Sharma, Tanu...

  19. Some bivalve trace fossils in the Mirosla Plička collection

    Czech Academy of Sciences Publication Activity Database

    Mikuláš, Radek; Uchman, A.

    Prague : Institute of Geology, AS CR, 2006 - (Mikuláš, R.; Rindsberg, A.). s. 25-26 ISBN 80-903511-2-3. [Workshop on Ichnotaxonomy /3./. 04.09.2006- 09.09.2006, Praha, Jevíčko] R&D Projects: GA ČR GA205/05/0917 Institutional research plan: CEZ:AV0Z30130516 Keywords : ichnofossils * bivalves * Protovirgularia * fossil behaviour Subject RIV: EG - Zoology

  20. Paralytic shellfish toxins in bivalves which are not associated with dinoflagellates.

    Science.gov (United States)

    Ogata, T; Sato, S; Kodama, M

    1989-01-01

    Paralytic shellfish toxins (PSP toxins) were detected in the freshwater bivalve Corbicula sandai collected from Lake Biwa, Shiga Prefecture, Japan, and marine mussel Septifer virgatus from Mutsu Bay where known causative dinoflagellates and their cysts have never been observed. The toxin profile of C. sandai and S. virgatus was considerably different from suspected causative organisms Aphanizomenon flos-aquae and Protogonyaulax spp., respectively. The causative organism(s) responsible for PSP toxins in these waters is at present unknown. PMID:2617541

  1. Biogeographic patterns of the marine bivalve Cerastoderma edule along the European coasts

    OpenAIRE

    Krakau, Manuela

    2008-01-01

    The cockle Cerastoderma edule is a common bivalve that inhabits the marine soft-bottom intertidal along European shores. This invertebrate plays a key role in coastal food webs of the Northeast Atlantic coasts due of its high abundances. I studied cockles from 19 sites along the distribution range with the aim to describe the variation of geographic population structures on different analytical levels. Cockles from the Barents Sea to the African Atlantic coast were analysed with respect to th...

  2. Investigation of the molecular ageing process of the long-lived bivalve Arctica islandica

    OpenAIRE

    Gruber, Heike

    2013-01-01

    The question on why we age and how ageing proceeds has occupied researchers’ minds for a long time. Demands on research of healthy ageing and geriatric diseases rise with an older growing human population. Thus, studying the mechanisms of ageing in animals with extraordinarily long lifespans could possibly reveal secrets to longevity and healthy ageing. In this study, a short-lived population of the bivalve mollusk Arctica islandica from the Baltic Sea (with a maximum lifesp...

  3. Paleogene marine bivalves of the deep-water Keasey Formation in Oregon, Part III: The heteroconchs

    OpenAIRE

    Hickman, Carole S.

    2015-01-01

    The heteroconch bivalve fauna of the deep-water (>200 m) Keasey Formation in northwestern Oregon records the Eocene–Oligocene climatic transition and replacement of tropical widely-distributed taxa by the cryophilic taxa that dominate modern high-latitude faunas of the North Pacific. Low-diversity assemblages occur in tuffaceous mudstone and siltstone facies of a deep nearshore basin at the onset of subduction on the Cascadia Margin. Six species of anomalodesmatan heteroconchs have been treat...

  4. Seston dynamics and bivalve feeding in the Bay of Marennes-Oléron (France)

    OpenAIRE

    Zurburg, Wouter; Smaal, Aad; Heral, Maurice; Dankers, Norbert

    1994-01-01

    Within the framework of an investigation into the carrying capacity of the Bay of Marennes-Oléron (France) for bivalve culture, the in situ uptake of suspended particulate material by oysters (Crassostrea gigas) and mussels (Mytilus edulis) was determined in experiments with benthic ecosystem tunnels. Very high fluctuations in seston quantity and quality were observed within and between tidal cycles. The percentage of organic carbon was inversely related to seston quantity at low concentratio...

  5. An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

    OpenAIRE

    Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche; Mazurié, Joseph; Buck, Bela H.; Dolmer, Per; Fraser, David; Van Nieuwenhove, Kris; O’Beirn, Francis X.; Sanchez-Mata, Adoración; Thorarinsdóttir, Gudrun G.; Strand, Øivind

    2012-01-01

    An ecosystem-based approach to bivalve aquaculture management is a strategy for the integration of aquaculture within the wider ecosystem, including human aspects, in such a way that it promotes sustainable development, equity, and resilience of ecosystems. Given the linkage between social and ecological systems, marine regulators require an ecosystem-based decision framework that structures and integrates the relationships between these systems and facilitates communication of aquaculture–en...

  6. Internal distribution of uranium and associated genotoxic damages in the chronically exposed bivalve Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Olivier, E-mail: olivier.simon@irsn.fr [Laboratoire de Radioecologie et Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat, 186 BP3, 13115 Saint Paul-Lez-Durance Cedex (France); Floriani, Magali; Cavalie, Isabelle; Camilleri, Virginie; Adam, Christelle; Gilbin, Rodolphe; Garnier-Laplace, Jacqueline [Laboratoire de Radioecologie et Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat, 186 BP3, 13115 Saint Paul-Lez-Durance Cedex (France)

    2011-08-15

    Uranium (U) internal distribution and involved effects in the bivalve Corbicula fluminea have been studied after direct chronic exposure (90 d, 10 {mu}g.L-1). U distribution was assessed at the subcellular level (Metal Rich Granules -MRG-, pellets and cytosol fractions) in two main organs of the bivalve (gills and visceral mass). Micro-localisation was investigated by TEM-EDX analysis in the gills epithelium. DNA damage in gill and hemolymph samples was measured by the Comet assay. The 90-d exposure period led to a significant increase of U concentration in gills over time (x5) and a large U quantity in subcellular granules in gills. Finally, a significant increase (x2) in DNA damage was noted in exposed gills and haemocytes. This study shows that the accumulation levels and consequently the potential toxicity cannot be successfully predicted only on the basis of concentration in water or in tissues and subcellular fractions after chronic exposure. - Highlights: > Relevant information concerning the chronic impact of uranium on biota is scarce. > We study its biological speciation to explain bioavailability, accumulation, toxicity. > 80% of U accumulated was measured in the pellet fraction (organelles + granules/MRG). > Chronic exposure to U induced genetic damage in gill and haemolymph cells of the bivalve.

  7. Triassic bivalves and the initial marine Mesozoic revolution: A role for predators?

    Science.gov (United States)

    McRoberts, Christopher A.

    2001-04-01

    Marine bivalves document the long-term increase in generic richness through the early Mesozoic. Following the end-Permian crisis, the Early Triassic was marked by a gradual recovery in generic richness (57 Induan and 66 Olenekian genera). Diversity slowly increased in the Middle Triassic (98 Anisian and 121 Ladinian genera) and peaked in the Late Triassic (171 Carnian, 165 Norian, and 143 Rhaetian genera). These data support earlier hypotheses that the recovery following the end-Permian extinction was very gradual and was not completed (in terms of both richness and ecologic complexity) until the Ladinian. Although a Carnian-Norian extinction is not evident in the data and may be a regional event limited to the Tethyan realm, the end-Triassic extinction is profound—fewer than 30 genera (reptiles), which had typically low abundances and limited distribution during the Triassic. Drilling predators, although present during the Triassic, are not considered to be prominent causes of mortality among bivalves. Instead, the infaunalization of bivalves during the Triassic may have been due to several interconnected abiotic and biotic causes associated with the recovery after the end-Permian mass extinction.

  8. Environmental changes and shallow marine fossil bivalve assemblages of the Lower Cretaceous Miyako Group, NE Japan

    Science.gov (United States)

    Fujino, Shigehiro; Maeda, Haruyoshi

    2013-03-01

    We reconstructed the environmental changes recorded in the Lower Cretaceous Miyako Group via facies analysis and delineated the relationship between depositional facies and the occurrence of diverse marine invertebrate macrofossils. The Miyako Group consists of deposits from alluvial bay-head delta, bay-head delta front, central bay, and lower shoreface to inner shelf depositional settings. Fossil bivalve assemblages responded to shifts in these sedimentary environments. We defined three fossil bivalve assemblages from the central bay and lower shoreface to inner shelf deposits. The assemblages in the inner shelf and central bay deposits are clearly different, even though they occur within similar depositional facies. This contrast in assemblages results from environmental differences between closed and open settings; this interpretation is supported by the occurrence of stenohaline crinoids. We defined a fourth bivalve assemblage in a tsunami deposit intercalated within the bay-head delta front deposits. It consists of polygenic allochthonous shells, some that were derived from an estuarine environment or the shallow seafloor and others that were torn from small reefs.

  9. Explosive demographic expansion by dreissenid bivalves as a possible result of astronomical forcing

    Directory of Open Access Journals (Sweden)

    M. Harzhauser

    2013-07-01

    Full Text Available Human induced range expansions of invasive dreissenid bivalves are of great concern. However, the underlying biological processes are only poorly understood, partly due to the lack of information on natural expansion events. Here we use the extinct bivalve species Sinucongeria primiformis as a model organism for testing natural (i.e. non-Anthropocene blooms of dreissenid species in a lacustrine system of Lake Pannon during the Tortonian (~10.5 Myr; Late Miocene. 600 samples from a consecutive core were evaluated for the relative abundance of this pavement-forming mollusc, which cover about 8 millennia of Late Miocene time with a decadal resolution. Our data indicate that the settlement by bivalves in the offshore environment was limited mainly by bottom water oxygenation, which follows predictable and repetitive patterns through time. These population fluctuations might be related to solar cycles: successful dreissenid settlement is re-occurring in a frequency known as the lower and upper Gleissberg cycles with a 50–80 and 90–120 yr period. These cycles appear to control regional wind patterns, which are directly linked to water mixing of the lake. This is modulated by the even more prominent 500 yr cycle, which seems to be the most important pacemaker for Lake Pannon hydrology.

  10. Bioaccumulation of cadmium bound to ferric hydroxide and particulate organic matter by the bivalve M. meretrix

    International Nuclear Information System (INIS)

    Ferric hydroxide and particulate organic matter are important pools of trace metals in sediments and control their accumulation by benthic animals. We investigated bioaccumulation of cadmium in bivalve Meretrix meretrix by using a simplified system of laboratory synthesized iron oxides and commercially obtained humic acids to represent the inorganic and organic matrix found in nature. The results showed that bioaccumulation characteristics were distinctly different for these two substrates. Bioaccumulation from ferric hydroxide was not observed at 70 and 140 mg/kg, while the clams started to absorb Cd at 140 mg/kg from organic matter and the bioaccumulation rate was faster than that from ferric hydroxide. Within 28 d, accumulation of Cd from organic matter appeared to reach a steady state after rising to a certain level, while absorption from ferric hydroxide appeared to follow a linear profile. The findings have implications about the assimilation of trace metals from sediments by benthic animals. - Highlights: ► Accumulation of Cd adsorbed on ferric hydroxide and particulate organics was studied. ► Bioaccumulation characteristics were distinctly different for the substrates. ► The result was attributed to different properties and bio-responses of the particles. ► Bivalves may not accumulate more metals associated with more bioavailable particles. - Bioaccumulation characteristics of adsorbed Cd on ferric hydroxide and particulate organic matter by bivalve M. meretrix are distinctly different.

  11. Availability of pearl producing marine bivalves in south-eastern coast of Bangladesh and culture potentialities

    Directory of Open Access Journals (Sweden)

    Md. Ataur Rahman

    2015-12-01

    Full Text Available The present study was conducted during September 2014 to July 2015 to identify the pearl bearing bivalves in south-eastern coast of Bangladesh and culture potentialities of marine oyster in captivity based on field investigation. A total of 7 pearl bearing bivalve species were identified in the coast with a salinity of 18-34 ppt, pH 8.1-8.3 and water depth ranged 0.2-2.0 meter in their habitat. From the collected bivalves, most abundant oyster species windowpane oyster, Placuna placenta (Linnaeus, 1758 was reared in fiber glass tanks with seawater for a period of 6 months. During rearing highest survival rate of 88% was observed in T1 with sandy and gravel substratum and lowest survival rate of 78% was found in T2 with muddy substratum. Average temperature and salinity were varied between 24 °C-25 °C and 21-26 ppt respectively. From the reared oyster, highest 54 nos. small pearls in the month of April and lowest 7 pearls in December from a single P. placenta were obtained. The study proved that pearls can be obtained from the marine oysters in captivity in Bangladesh, and this offers large scale culture potentialities in our coast.

  12. Ethno-malacological knowledge of bivalve mollusks gathering in Acupe mangrove, Santo Amaro, Bahia

    Directory of Open Access Journals (Sweden)

    Francisco José Bezerra Souto

    2009-12-01

    Full Text Available The mangrove is a highly productive ecosystem that carries out important ecological functions and that historically it has been used for the subsistence and income of countless craft fishing communities. In the mangroves of Todos os Santos Bay, including those of the District of Acupe (Santo Amaro – Bahia State, the bivalve mollusks (shellfish are among the most important resources, and their gathering is known as “mariscagem”. This work aims to characterize the knowledge of the local female shellfish gatherers regarding the biology and ecology of bivalve shellfish. Semi-structured interviews were used with local shellfish women (N=54 involving ethnotaxonomy, trophic ecology, hydrodynamics, fenology and ethnocronology. Etic-emic analisys of the data was chosen in order to compare the information obtained in the field to that from the academic literature. The results demonstrated that the shellfish women of Acupe have a significant knowledge of bivalve shellfish, in addition to aspects related to the dynamics of local mangroves, that is sometimes compatible with academic knowledge.

  13. Cutaneous Manifestations in Inflammatory Bowel Diseases

    Directory of Open Access Journals (Sweden)

    Simona Roxana Georgescu

    2015-10-01

    Full Text Available Inflammatory bowel diseases have a high frequency in Europe. They are chronic disorders that evolve with relapses and remissions. Clinical features include the signs of underlying inflammatory bowel disease and also signs of extraintestinal manifestations. Cutaneous disorders are the most common extraintestinal manifestations associated with inflammatory bowel diseases, which can be dependent on or independent of gastrointestinal disease activity. The main cutaneous disorders are erythema nodosum and pyodermagangrenosum. The pathogenic mechanisms are not fully understood but it seems that related mechanisms are involved in the development of inflammatory bowel diseases and extraintestinal manifestations. Treatment should be aimed at both the cutaneous manifestations and the bowel inflammation

  14. Influence of food on the assimilation of selected metals in tropical bivalves from the New Caledonia lagoon: qualitative and quantitative aspects

    OpenAIRE

    Hédouin, Laëtitia; Metian, Marc; Lacoue-Labarthe, Thomas; Fichez, Renaud; Bustamante, Paco; Warnau, Michel

    2010-01-01

    The present study aimed at examining the influence of food quality and quantity on the assimilation efficiency (AE) of metals in two abundant bivalves in the New Caledonia lagoon, the oyster Isognomon isognomon and the clam Gafrarium tumidum. Bivalves were exposed via their food to the radiotracers of three metals of concern in New Caledonia (54Mn, 57Co and 65Zn) under different feeding conditions (phytoplankton species, cell density, and cell-associated metal concentration). When bivalves we...

  15. The radiological manifestation of cryptococcosis

    International Nuclear Information System (INIS)

    Cryptococcosis is an uncommon mycotic disease caused by Cryptococcosis neoformans, with a special affinity for the respiratory and central nervous system, and less frequently affecting liver, spleen, skin, lymph nodes and kidney. It was first described by Busse in 1984, and since then the occurrences had been world-widely reported with increasing incidence. The outcome of the disease may be fatal when the treatment is delayed. The main portal of entry is via the respiratory tract, and the pulmonary manifestations are not specific but quite varying, that solitary or multiple pulmonary masses, nodular or reticular infiltrations, cavity formation, lymphadenopathy or pleural effusion can be detected on the chest X-ray film simulating many other diseases. Authors analyzed and evaluated 16 cases of confirmed cryptococcosis, and interesting clinical and radiologic features that definitely differed from most of the other reports were notable as follows: 1. The incidence of cryptococcosis ranks 3rd (4.3%) among deep mycoses, next to moniliasis and aspergillosis. 2. 15 of 16 patients are in the period of pediatric age under 16 year old of age. 3. There are no remarkable underlying diseases or predisposing factors encountered in all of the 16 cases. 4. Besides the predominating meningeal irritating symptoms, the involvement of the reticuloendothelial system, l.e., lymph nodes, liver and spleen are notable. 5. Characteristic features of the pulmonary cryptococcosis are: a) 8 of 10 cases have marked hilar and paratracheal lymph nodes enlargement. b) None of the cases reveals solitary pulmonary mass, cavity formation or pleural effusion. c) The lung infiltrations are mainly reticular or coarse nodular pattern. d) The infiltrations s are diffusely distributed on entire lung field, rather than the predilection for the lower lobe. 6. Similarly to most of the other reports, the central nervous system involvement are most frequent (12 of 16 cases). 7. The combined therapy with

  16. Cystic thymic diseases: CT manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Song, Soon Young; Choi, Yo Won; Jeon, Eui Yong; Jeon, Seok Chol; Seo, Heung Suk; Hahm, Chang Kok [School of Medicine, Hanyang University, Seoul (Korea, Republic of)

    1995-09-15

    To describe CT findings and differential points of cystic thymic lesions. We evaluated retrospectively total 19 masses with well marginated cystic lesions at thymic area on CT scans. They were 10 teratomas, 3 congenital thymic cysts, 2 multilocular thymic cysts(associated with thymoma and myasthenia gravis in each), 2 cysts Assciated with thymic Hodgkin's lymphomas an ectopic parathyroid cyst, and an infected thymic cyst. The radiological abnormalities evaluated were thickness of the wall, presence or abscene of septa, mural nodule, solid component, calcification and fat component. All three cases of congenital thymic cysts and an ectopic parathyroid cyst appeared as thin-walled unilocular cyst with homogeneous internal density and without identifiable solid component. In multilocular thymic cyst, there were thick wall and solid components(n =2), thick internal septa and calcifications(n = 1). The cysts of teratomas manifested thick walls(n = 9), internal septa(n = 4), calcifications(n = 6), fat components(n = 4), and solid components(n = 4). Cysts in Hodgkin's diseases appeared as multilocular or unilocular and had thick wall and septa without calcification. Infected thymic cyst presented with multilocular cystic mass with identifiable wall and septa, calcification, and solid components. The thymic diseases with cystic lesion include teratomas, congenital thymic cysts, multilocular thymic cysts, parathyroid cyst, and Hodgkin's disease. Congenital thymic cyst and ectopic parathyroid cyst are thin-walled unilocular cystic lesions. Cystic lesions associated with teratoma, Hodgkin's disease, and multilocular thymic cyst are thick-walled cystic lesions with or without solid component.

  17. Endocrine manifestations of celiac disease

    Directory of Open Access Journals (Sweden)

    R Philip

    2012-01-01

    Full Text Available Background: Celiac disease can have extra gastrointestinal tract (GIT presentations, most of which are endocrine. The aim of this study was to present patients diagnosed to have celiac disease from an endocrine department and to study the prevalence of endocrinopathies in celiac disease. Materials and Methods: A total of 36 patients from the endocrinology department (LLRM Medical College, Meerut between January 2011 and July 2012 and who were diagnosed to have celiac disease were included in the study. Results: Short stature was the commonest presentation (25%, other presentations included short stature and delayed puberty (20%, delayed puberty (11%, screening for celiac disease in type-1 DM patients (17%, rickets (6%, anemia not responding to oral therapy (6%, type-1 DM with recurrent hypoglycaemia (6%, and osteomalacia (3%. The endocrine manifestations include (after complete evaluation short stature (58%, delayed puberty (31%, elevated alkaline phospahatase (67%, low calcium (22%, X-rays suggestive of osteomalacia or rickets (8%, capopedal spasm (6%, and night blindness (6%. Anti-TPO antibody positivity was found in 53%, hypothyroidism in 28%, subclinical hypothyroidism in 17%, and type-1 DM in 25% of the patients. A total of 14% patients had no GI symptoms. Conclusion: Celiac disease is an endocrine disrupter as well as the great masquerader having varied presentations including short stature, delayed puberty, and rickets. Some patients who have celiac disease may not have any GI symptoms, making the diagnosis all the more difficult. Also, there is significant incidence of celiac disease with hypothyroidism and type-1 DM, making screening for it important in these diseases.

  18. Coexistence of Pacific oyster Crassostrea gigas (Thunberg, 1793) and blue mussels Mytilus edulis Linnaeus, 1758 on a sheltered intertidal bivalve bed?

    DEFF Research Database (Denmark)

    Holm, M.W.; Davids, J.K.; Dolmer, Per;

    2016-01-01

    and M. edulis were collected from the bivalve bed, shell lengths were converted into biomass, which were interpolated to create biomass contours and combined with modelled topography of the bivalve bed to study niche separation. The bivalve bed slowly extended northwards over a period of 11 years, where......, and as C. gigas have been present in the ecosystem for more than 40 years, we hypothesize that the presence of C. gigas has altered the spatial and temporal distribution of M. edulis by inducing a niche separation. The spatiotemporal development of the bivalve bed was determined using orthophotos. C. gigas...

  19. Museum Preserved Bivalves as Indicators of Long-term Trends in Methylmercury Concentrations

    Science.gov (United States)

    Luengen, A. C.; Foslund, H. M.; Greenfield, B. K.

    2015-12-01

    Despite the many efforts to reduce mercury concentrations in the environment, there are relatively few datasets on long-term trends in mercury in biota, especially for the bioavailable form, methylmercury (MeHg). This study used museum preserved bivalves (stored in ethanol) to look at MeHg trends in the Asian date mussel Musculista senhousia and the Asian clam Potamocorbula amurensis, collected from San Francisco Bay, California between 1975 and 2012. For each sampling date, 4 to 15 individuals were obtained from museum collections (N = 156 total specimens), freeze-dried, weighed, homogenized, digested, and individually analyzed for MeHg using trace metal clean techniques. The bivalves were also analyzed for δ13C and δ15N to look for changes in food web structure. P. amurensis specimens were only available from 1988 to 2012, and an increase in MeHg was observed during that time. In contrast, M. senhousia specimens were available for the entire 37 year period and exhibited a significant decline in MeHg in the southern reach of the estuary (South Bay). The median MeHg concentration in M. senhousia was highest at 239 ng/g dw in October 1975. That year was the last year of operations for the New Almaden Mercury Mining District, which drained into South Bay. By the 1990s, MeHg concentrations in M. senhousia dropped significantly to a median of 37 ng/g dw. Isotopic δ15N values did not support a hypothesis of reduced trophic position causing the MeHg decline. Over the study duration, δ15N increased in M. senhousia, which we attributed to a baseline shift. We also observed a decline in δ13C since 2000, which may represent a shift in bivalve carbon towards greater utilization of planktonic sources. To validate the use of museum specimens, we ran a preservation study, where we collected fresh bivalves, fixed them in ethanol or formalin, and then transferred them to ethanol for long-term storage. Although MeHg concentrations increased after 1 week, they stabilized over

  20. Uncharted waters: Bivalves of midway atoll and integrating mathematics into biology education

    Science.gov (United States)

    McCully, Kristin M.

    To protect and conserve the Earth's biodiversity and ecosystem services, it is important not only to understand and conserve species and ecosystems, but also to instill an understanding and appreciation for biodiversity and ecosystem services in the next generations of both scientists and citizens. Thus, this dissertation combines research into the ecology and identity of large bivalves at Midway Atoll in the Northwestern Hawaiian Islands (NWHI) with research on pedagogical strategies for integrating mathematics into undergraduate biology education. The NWHI is one of the few remaining large, mainly intact, predator-dominated coral reef ecosystems and one of the world's largest marine protected areas. Previous bivalve studies focused on the black-lipped pearl oyster, Pinctada margaritifera, which was heavily harvested in the late 1920s, has not recovered, and is now a candidate species for restoration. First, I combined remote sensing, geographic information systems, SCUBA, and mathematical modeling to quantify the abundance, spatial distributions, and filtration capacity of large epifaunal bivalves at Midway Atoll. These bivalves are most abundant on the forereef outside the atoll, but densities are much lower than reported on other reefs, and Midway's bivalves are unlikely to affect plankton abundance and productivity inside the lagoon. Second, I used molecular techniques and phylogenetic reconstructions to identify pearl oysters (Pinctada) from Midway Atoll as P. maculata , a species not previously reported in Hawaii. As a small morphologically cryptic species, P. maculata may be a native species that has not been collected previously, a native species that has been identified incorrectly as the morphologically similar P. radiata, or it may be a recent introduction or natural range extension from the western Pacific. Finally, I review science education literature integrating mathematics into undergraduate biology curricula, and then present and evaluate a

  1. Congenital rubella syndrome and delayed manifestations

    DEFF Research Database (Denmark)

    Dammeyer, Jesper Herup

    2010-01-01

    Objective: Several hypotheses of different medical and psychological delayed manifestations among people who have congenital rubella syndrome (CRS) have been discussed. This study tests some of these hypotheses of delayed manifestations. Methods: Gathering information about 35 individuals who have...

  2. 19 CFR 123.32 - Manifests.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Manifests. 123.32 Section 123.32 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through the United States § 123.32 Manifests. (a) Form and number of copies required....

  3. Oral manifestations of syphilis: a review

    Directory of Open Access Journals (Sweden)

    A.B. Soares

    2004-01-01

    Full Text Available Syphilis is an infectious disease presenting stages associated with specific oral lesions. Therefore, health professionals should be familiar with the different syphilis oral manifestations at each stage and be prepared to refer any suspected patient for further evaluation. This report describes the most important clinical factors of each stage, emphasizing the oral manifestations.

  4. Clinical manifestations of zinc deficiency.

    Science.gov (United States)

    Prasad, A S

    1985-01-01

    The essentiality of zinc for humans was recognized in the early 1960s. The causes of zinc deficiency include malnutrition, alcoholism, malabsorption, extensive burns, chronic debilitating disorders, chronic renal diseases, following uses of certain drugs such as penicillamine for Wilson's disease and diuretics in some cases, and genetic disorders such as acrodermatitis enteropathica and sickle cell disease. In pregnancy and during periods of growth the requirement of zinc is increased. The clinical manifestations in severe cases of zinc deficiency include bullous-pustular dermatitis, alopecia, diarrhea, emotional disorder, weight loss, intercurrent infections, hypogonadism in males; it is fatal if unrecognized and untreated. A moderate deficiency of zinc is characterized by growth retardation and delayed puberty in adolescents, hypogonadism in males, rough skin, poor appetite, mental lethargy, delayed wound healing, taste abnormalities, and abnormal dark adaptation. In mild cases of zinc deficiency in human subjects, we have observed oligospermia, slight weight loss, and hyperammonemia. Zinc is a growth factor. Its deficiency adversely affects growth in many animal species and humans. Inasmuch as zinc is needed for protein and DNA synthesis and for cell division, it is believed that the growth effect of zinc is related to its effect on protein synthesis. Whether or not zinc is required for the metabolism of somatomedin needs to be investigated in the future. Testicular functions are affected adversely as a result of zinc deficiency in both humans and experimental animals. This effect of zinc is at the end organ level; the hypothalamic-pituitary axis is intact in zinc-deficient subjects. Inasmuch as zinc is intimately involved in cell division, its deficiency may adversely affect testicular size and thus affect its functions. Zinc is required for the functions of several enzymes and whether or not it has an enzymatic role in steroidogenesis is not known at present

  5. Abdominal manifestations of autoimmune disorders

    International Nuclear Information System (INIS)

    Full text: Immunoglobulin G4-related disease was recognized as a systemic disease since various extrapancreatic lesions were observed in patients with autoimmune pancreatitis (AIP). The real etiology and pathogenesis of IgG4-RD is still not clearly understood. Moreover the exact role of IgG4 or IgG4-positive plasma cells in this disease has not yet been elucidated. only some inconsistent biological features such as hypergammaglobulinemia or hypocomplementemia support the autoimmune nature of the disease process. various names have been ascribed to this clinicopathological entity including IgG4-related sclerosing disease, IgG4-related systemic sclerosing disease, IgG4-related disease, IgG4-related autoimmune disease, hyper-IgG4 disease and IgG4-related systemic disease. The extrapancreatic lesions of IgG4-RD also exhibit the same characteristic histologic features including dense lymphoplasmacytic infiltrate, massive storiform fibrosis, and obliterative phlebitis as seen in IgG4-related pancreatitis. Abdominal manifestations include the following organs/systems: Bile ducts: Sclerosing cholangitis; Gallbladder and liver: Acalculous sclerosis cholecytitis with diffuse wall thickening; hepatic inflammatory pseudotumorts; Kidneys: round or wedge-shaped renal cortical nodules, peripheral cortical; lesions, mass like lesions or renal pelvic involvement; Prostate, urethra, seminal vesicle, vas deferens, uterine cervix; Autoimmune prostatitis; Retroperitoneum: Retroperitoneal fibrosis. thin or mildly thick homogeneous soft tissue lesion surrounding the abdominal aorta and its branches but also bulky masses causing hydronephroureterosis; Mesentery: Sclerosing mesenteritis usually involving the root of the mesentery; Bowel: Inflammatory bowel diseases mimicking Crohn’s disease or ulcerative colitis. various types of sclerosing nodular lesions of the bowel wall; Stomach: Gastritis, gastric ulcers and focal masses mimicking submucosal tumor; omentum: Infiltration mimicking

  6. Permian bivalves of the Taciba Formation, Itararé Group, Paraná Basin, and their biostratigraphic significance

    Directory of Open Access Journals (Sweden)

    Marcello Guimarães Simões

    2012-04-01

    Full Text Available A small and poorly diversified bivalve fauna from Taciba Formation, Itararé Group, Paraná Basin (State of Santa Catarina,Mafra Municipality, is described in this paper for the first time, based on new findings. The fauna is recorded in a 30 cmthick interval of fine sandstone locally at the top of Taciba Formation, in the Butiá quarry. The studied fossil-bearing sandstonebed is a marine intercalation recording a brief eustatic rise in sea-level, probably following glacier retreat and climateamelioration at the end of a broad glacial scenario. The fauna is mainly dominated by productid brachiopods, which are notdescribed here, and rare mollusk shells (bivalves and gastropods. Two bivalve species were identified: Myonia argentinensis(Harrington, 1955, and Aviculopecten multiscalptus (Thomas, 1928. The presence of Myonia argentinensis is noteworthysince this species is also present in the Baitaca assemblage found in marine siltstones (Baitaca assemblage of theRio do Sul Formation, cropping out at the Teixeira Soares region, Paraná State. This species is also recorded in the bivalvefauna from the Bonete Formation, Pillahinco Group, Sauce Grande Basin, Buenos Aires Province, in Argentina. Hence, themarine bivalves of the Taciba Formation are associated with the transgressive event that characterizes the Eurydesma fauna,indicating a Late Asselian-Sakmarian age for the bivalve fauna. Presence of the Myonia argentinensis megadesmid speciesreinforces the Gondwanic nature of the studied fauna.

  7. Validating the Incorporation of 13C and 15N in a Shorebird That Consumes an Isotopically Distinct Chemosymbiotic Bivalve.

    Science.gov (United States)

    van Gils, Jan A; Ahmedou Salem, Mohamed Vall

    2015-01-01

    The wealth of field studies using stable isotopes to make inferences about animal diets require controlled validation experiments to make proper interpretations. Despite several pleas in the literature for such experiments, validation studies are still lagging behind, notably in consumers dwelling in chemosynthesis-based ecosystems. In this paper we present such a validation experiment for the incorporation of 13C and 15N in the blood plasma of a medium-sized shorebird, the red knot (Calidris canutus canutus), consuming a chemosymbiotic lucinid bivalve (Loripes lucinalis). Because this bivalve forms a symbiosis with chemoautotrophic sulphide-oxidizing bacteria living inside its gill, the bivalve is isotopically distinct from 'normal' bivalves whose food has a photosynthetic basis. Here we experimentally tested the hypothesis that isotope discrimination and incorporation dynamics are different when consuming such chemosynthesis-based prey. The experiment showed that neither the isotopic discrimination factor, nor isotopic turnover time, differed between birds consuming the chemosymbiotic lucinid and a control group consuming a photosynthesis-based bivalve. This was true for 13C as well as for 15N. However, in both groups the 15N discrimination factor was much higher than expected, which probably had to do with the birds losing body mass over the course of the experiment. PMID:26458005

  8. Validating the Incorporation of 13C and 15N in a Shorebird That Consumes an Isotopically Distinct Chemosymbiotic Bivalve.

    Directory of Open Access Journals (Sweden)

    Jan A van Gils

    Full Text Available The wealth of field studies using stable isotopes to make inferences about animal diets require controlled validation experiments to make proper interpretations. Despite several pleas in the literature for such experiments, validation studies are still lagging behind, notably in consumers dwelling in chemosynthesis-based ecosystems. In this paper we present such a validation experiment for the incorporation of 13C and 15N in the blood plasma of a medium-sized shorebird, the red knot (Calidris canutus canutus, consuming a chemosymbiotic lucinid bivalve (Loripes lucinalis. Because this bivalve forms a symbiosis with chemoautotrophic sulphide-oxidizing bacteria living inside its gill, the bivalve is isotopically distinct from 'normal' bivalves whose food has a photosynthetic basis. Here we experimentally tested the hypothesis that isotope discrimination and incorporation dynamics are different when consuming such chemosynthesis-based prey. The experiment showed that neither the isotopic discrimination factor, nor isotopic turnover time, differed between birds consuming the chemosymbiotic lucinid and a control group consuming a photosynthesis-based bivalve. This was true for 13C as well as for 15N. However, in both groups the 15N discrimination factor was much higher than expected, which probably had to do with the birds losing body mass over the course of the experiment.

  9. [Lyme disease--clinical manifestations and treatment].

    Science.gov (United States)

    Stock, Ingo

    2016-05-01

    Lyme disease (Lyme borreliosis) is a systemic infectious disease that can present in a variety of clinical manifestations. The disease is caused by a group of spirochaetes--Borrelia burgdorferi sensu lato or Lyme borrelia--that are transmitted to humans by the bite of Ixodes ticks. Lyme disease is the most common arthropode-borne infectious disease in many European countries including Germany. Early localized infection is typically manifested by an erythema migrans skin lesion, in rarer cases as a borrelial lymphocytoma. The most common early disseminated manifestation is (early) neuroborreliosis. In adults, neuroborreliosis appears typically as meningoradiculoneuritis. Neuroborreliosis in children, however, is typically manifested by meningitis. In addition, multiple erythema migrans lesions and Lyme carditis occur relatively frequently. The most common manifestation oflate Lyme disease is Lyme arthritis. Early manifestations (and usually also late manifestations) of Lyme disease can be treated successfully by application of suitable antibacterial agents. For the treatment of Lyme disease, doxycycline, certain penicillins such as amoxicillin and some cephalosporins (ceftriaxone, cefotaxime, cefuroxime axetil) are recommended in current guidelines. A major challenge is the treatment of chronic, non-specific disorders, i. e., posttreatment Lyme disease syndrome and "chronic Lyme disease". Prevention of Lyme disease is mainly accomplished by protecting against tick bites. Prophylactic administration of doxycycline after tick bites is generally not recommended in Germany. There is no vaccine available for human beings. PMID:27348896

  10. Genetic alterations in syndromes with oral manifestations

    Directory of Open Access Journals (Sweden)

    Krishnamurthy Anuthama

    2013-01-01

    Full Text Available Ever since Gregor Johan Mendel proposed the law of inheritance, genetics has transcended the field of health and has entered all walks of life in its application. Thus, the gene is the pivoting factor for all happenings revolving around it. Knowledge of gene mapping in various diseases would be a valuable tool in prenatally diagnosing the condition and averting the future disability and stigma for the posterity. This article includes an array of genetically determined conditions in patients seen at our college out-patient department with complete manifestation, partial manifestation and array of manifestations not fitting into a particular syndrome.

  11. Differential reproductive strategies of two bivalves in the Dutch Wadden Sea

    Science.gov (United States)

    Cardoso, Joana F. M. F.; Witte, Johannes IJ.; van der Veer, Henk W.

    2009-08-01

    Cerastoderma edule and Mya arenaria are two common bivalve species in European waters. Longevity and maximum size are much greater in the latter species. Because comparison of species life-history strategies states that a long life span (i.e. high annual survival) generally goes with lower fecundity, we hypothesise that reproductive output would be lower in M. arenaria than in C. edule. In the present paper, we studied the reproductive strategies of these two species in an intertidal and a subtidal area of the western Dutch Wadden Sea, by following seasonal changes in absolute and relative weights of somatic and gonadal tissues in these bivalves. Starting of spawning was similar in the two species, around May, except for intertidal M. arenaria, which initiated spawning in August. Individual energy investment in reproduction was similar for the two species but, unlike M. arenaria, C. edule spawned completely, releasing all energy of gonadal mass in the form of gametes. Mya arenaria used the gonad not only for reproduction but also for storage. In the intertidal area, we found a trade-off between longevity and reproduction, i.e. maximum reproductive output (expressed as a proportion of body mass) was higher in C. edule than in M. arenaria. However, since body size is larger and life span longer in M. arenaria than in C. edule, mean lifetime reproductive output per individual must be higher in the first than in the latter. Based on the differences in reproductive strategies of these two species, we hypothesise that the negative effects of warming climate on bivalve population dynamics in the Wadden Sea will be stronger in C. edule than in M. arenaria.

  12. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    Energy Technology Data Exchange (ETDEWEB)

    Praveen Kumar, M.K., E-mail: here.praveen@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Shyama, S.K., E-mail: skshyama@gmail.com [Department of Zoology, Goa University, Goa 403206 (India); Sonaye, B.S. [Department of Radiation Oncology, Goa Medical College, Goa (India); Naik, U Roshini; Kadam, S.B.; Bipin, P.D.; D’costa, A. [Department of Zoology, Goa University, Goa 403206 (India); Chaubey, R.C. [Radiation Biology and Health Science Division, Bhabha Atomic Research Centre, Mumbai (India)

    2014-05-01

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  13. Evaluation of γ-radiation-induced DNA damage in two species of bivalves and their relative sensitivity using comet assay

    International Nuclear Information System (INIS)

    Highlights: • Possible genotoxic effect of accidental exposure of aquatic fauna to γ radiation. • Relative sensitivity of bivalves to γ radiation is also analyzed using comet assay. • γ radiation induced significant genetic damage in both the species of bivalves. • P. malabarica and M. casta exhibited a similar level of sensitivity to γ radiation. • Comet assay may be used as a biomarker for the environmental biomonitoring. - Abstract: Ionizing radiation is known to induce genetic damage in diverse groups of organisms. Under accidental situations, large quantities of radioactive elements get released into the environment and radiation emitted from these radionuclides may adversely affect both the man and the non-human biota. The present study is aimed (a) to know the genotoxic effect of gamma radiation on aquatic fauna employing two species of selected bivalves, (b) to evaluate the possible use of ‘Comet assay’ for detecting genetic damage in haemocytes of bivalves as a biomarker for environmental biomonitoring and also (c) to compare the relative sensitivity of two species of bivalves viz. Paphia malabarica and Meretrix casta to gamma radiation. The comet assays was optimized and validated using different concentrations (18, 32 and 56 mg/L) of ethyl methanesulfonate (EMS), a direct-acting reference genotoxic agent, to which the bivalves were exposed for various times (24, 48 and 72 h). Bivalves were irradiated (single acute exposure) with 5 different doses (viz. 2, 4, 6, 8 and 10 Gy) of gamma radiation and their genotoxic effects on the haemocytes were studied using the comet assay. Haemolymph was collected from the adductor muscle at 24, 48 and 72 h of both EMS-exposed and irradiated bivalves and comet assay was carried out using standard protocol. A significant increase in DNA damage was observed as indicated by an increase in % tail DNA damage at different concentrations of EMS and all the doses of gamma radiation as compared to controls in

  14. The use of bivalves as bio-indicators in the assessment of marine pollution along a coastal area

    International Nuclear Information System (INIS)

    The assessment of environmental pollution of the coastal areas of the Malaysian Peninsula was done by analyzing the contents of the heavy and trace elements in the bivalves blood clams (Anadara granosa) and green mussels (Perna viridis) and sediments at twenty-two sampling stations to look for prevailing trends. Heavy and trace elements analyzed in this study were As, Cd, Cr, Cu, Pb, Se and Zn. Two techniques, namely the neutron activation analysis (NAA) and atomic absorption spectrophotometry (AAS) were used in the quantitative determination of the heavy metals while Marine Sediment Reference Material (BCSS) and Lobster Hepatopancreas (TORT-1) provided the certified reference materials in the quality assurance control. The potential use of these bivalves as suitable bio-indicators was evaluated from correlation tests based on the concentrations of heavy and trace elements in the sediment-metals system to those in the bivalves. (author)

  15. Bioaccumulation, Toxicity And Decontamination Studies Of Some Radioisotopes From Radioactive Polluted Water By The Bivalve Carotol Carotol

    International Nuclear Information System (INIS)

    In this study, the bivalve Caelatura caelatura was examined as radiobio-indicator for some radioisotopes namely 134Cs and60Co in polluted water. The uptake process was followed at different concentrations of the radioisotope solutions and the concentration factor values were calculated. Studies of the accumulation of these radioisotopes and their toxic effects on survival of these bivalves were followed for six weeks and also the lethal dose (LD50) was calculated. Decontamination studies were also performed in water and ethylene diamine tetra acetic acid (EDTA). The results showed that the bivalve Caelatura caelatura can be considered as good radiobioindicator for some radioisotopes in polluted water due to its high concentration factor values and high tolerant for radioisotopes solutions.

  16. Diabetic encephalopathy: Pathogenesis, clinical manifestations, therapy approaches

    Directory of Open Access Journals (Sweden)

    I. Kh. Khairullin

    2014-07-01

    Full Text Available The paper considers the epidemiology, morphology, and clinical manifestations of diabetic encephalopathy. It shows the differences of diabetic encephalopathy in types 1 and 2 diabetes mellitus. Pathogenetic treatment options for diabetic encephalopathy are given.

  17. Diabetic encephalopathy: Pathogenesis, clinical manifestations, therapy approaches

    OpenAIRE

    I. Kh. Khairullin; S. T. Zyangirova; Yu. N. Isayeva; O. R. Esin

    2014-01-01

    The paper considers the epidemiology, morphology, and clinical manifestations of diabetic encephalopathy. It shows the differences of diabetic encephalopathy in types 1 and 2 diabetes mellitus. Pathogenetic treatment options for diabetic encephalopathy are given.

  18. Diabetic encephalopathy: Pathogenesis, clinical manifestations, therapy approaches

    Directory of Open Access Journals (Sweden)

    I. Kh. Khairullin

    2012-01-01

    Full Text Available The paper considers the epidemiology, morphology, and clinical manifestations of diabetic encephalopathy. It shows the differences of diabetic encephalopathy in types 1 and 2 diabetes mellitus. Pathogenetic treatment options for diabetic encephalopathy are given.

  19. Mucocutaneous manifestations of helminth infections: Nematodes.

    Science.gov (United States)

    Lupi, Omar; Downing, Christopher; Lee, Michael; Pino, Livia; Bravo, Francisco; Giglio, Patricia; Sethi, Aisha; Klaus, Sidney; Sangueza, Omar P; Fuller, Claire; Mendoza, Natalia; Ladizinski, Barry; Woc-Colburn, Laila; Tyring, Stephen K

    2015-12-01

    In the 21st century, despite increased globalization through international travel for business, medical volunteerism, pleasure, and immigration/refugees into the United States, there is little published in the dermatology literature regarding the cutaneous manifestations of helminth infections. Approximately 17% of travelers seek medical care because of cutaneous disorders, many related to infectious etiologies. This review will focus on the cutaneous manifestations of helminth infections and is divided into 2 parts: part I focuses on nematode infections, and part II focuses on trematode and cestode infections. This review highlights the clinical manifestations, transmission, diagnosis, and treatment of helminth infections. Nematodes are roundworms that cause diseases with cutaneous manifestations, such as cutaneous larval migrans, onchocerciasis, filariasis, gnathostomiasis, loiasis, dracunculiasis, strongyloidiasis, ascariasis, streptocerciasis, dirofilariasis, and trichinosis. Tremadotes, also known as flukes, cause schistosomiasis, paragonimiasis, and fascioliasis. Cestodes (tapeworms) are flat, hermaphroditic parasites that cause diseases such as sparganosis, cysticercosis, and echinococcus. PMID:26568337

  20. Dermatitis Herpetiformis: Skin Manifestation of Celiac Disease

    Science.gov (United States)

    ... list of Celiac Disease Organizations​​ . Alternate Language URL Dermatitis Herpetiformis: Skin Manifestation of Celiac Disease (For Health ... this page: Symptoms Causes Diagnosis Treatment Clinical Trials Dermatitis herpetiformis (DH) is a chronic, intensely itchy, blistering ...

  1. Tuberous sclerosis - clinical manifestations and genetic implications

    International Nuclear Information System (INIS)

    Twenty-five patients with tuberous sclerosis have been studied with regard to their clinical manifestations, radiological features and genetic background. The practical implications of the condition in southern Africa are reviewed with reference to the literature

  2. Ophthalmological manifestations in segmental neurofibromatosis type 1

    OpenAIRE

    Ruggieri, M; Pavone, P; Polizzi, A; Pietro, M Di; Scuderi, A; A GABRIELE; Spalice, A; IANNETTI, P

    2004-01-01

    Aims: To study the ophthalmological manifestations in individuals with the typical features of neurofibromatosis type 1 (NF1) circumscribed to one or more body segments, usually referred to as segmental NF1.

  3. Manifest toob klassika taas kinoekraanile / Andri Maimets

    Index Scriptorium Estoniae

    Maimets, Andri, 1979-

    2007-01-01

    2.-9. veebr. on kinos "Sõprus" ja 11.-15. veebr. Tartu Sadamateatris 5. kultusfilmide festival Manifest, seekord USA filmid ja teemaks sõnavabadus. Esilinastub ka Urmas E. Liivi dokumentaalfilm "Tervitusi Nõukogude Eestist!"

  4. Musculoskeletal manifestations of the antiphospholipid syndrome.

    Science.gov (United States)

    Noureldine, M H A; Khamashta, M A; Merashli, M; Sabbouh, T; Hughes, G R V; Uthman, I

    2016-04-01

    The scope of clinical and laboratory manifestations of the antiphospholipid syndrome (APS) has increased dramatically since its discovery in 1983, where any organ system can be involved. Musculoskeletal complications are consistently reported in APS patients, not only causing morbidity and mortality, but also affecting their quality of life. We reviewed all English papers on APS involvement in the musculoskeletal system using Google Scholar and Pubmed; all reports are summarized in a table in this review. The spectrum of manifestations includes arthralgia/arthritis, avascular necrosis of bone, bone marrow necrosis, complex regional pain syndrome type-1, muscle infarction, non-traumatic fractures, and osteoporosis. Some of these manifestations were reported in good quality studies, some of which showed an association between aPL-positivity and the occurrence of these manifestations, while others were merely described in case reports. PMID:26923284

  5. Investigating the impact of drilling mud and its major components on bivalve species of Georges Bank

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    The objective of this program has been to measure the response of commercially important marine bivalve molluscs to low levels of drilling muds. Because these materials are composed of several major components whose proportions vary between wells and with depth for a single well, the approach of this study has been to test the major components individually and then to test a representative synthetic mud and finally a used drilling mud from an offshore platform. In all but one of these tests the target organism has been the sea scallop, Placopecten magellanicus.

  6. Moluscos bivalves em Portugal: composição química e metais contaminantes

    OpenAIRE

    Oliveira, Maria Cidália Rodrigues Mendes de

    2012-01-01

    A cultura e consumo de moluscos bivalves em Portugal são atividades cujo início se perde no tempo e com um grande impacto na economia nacional. Contudo, o consumo destes organismos envolve problemas específicos de segurança alimentar pelo que é necessário um controlo rigoroso associado a um plano de monitorização. A amêijoa japonesa (Ruditapes philippinarum), a ameijola (Callista chione), a lambujinha (Scrobicularia plana), o mexilhão (Mytilus edulis) e a ostra portuguesa (Crassostrea angu...

  7. Bivalve aquaculture transfers in Atlantic Europe. Part A: Transfer activities and legal framework

    DEFF Research Database (Denmark)

    Muehlbauer, F.; Fraser, D.; Brenner, M.; Van Nieuwenhove, K.; Buck, B.H.; Strand, O.; Mazurié, J.; Thorarinsdottir, G.; Dolmer, Per; O`Beirn, F.; Sanchez-Mata, A.; Flimlin, G.; Kamermans, P.

    2014-01-01

    of exotic species around the world. Threats due to the transfer and introduction of species have been identified and a range of global and regional agreements, guidelines, standards and statutes to minimize effects have been established. Yet whether such regulations can protect and conserve the......Intentional transfers of numerous bivalve species have had a long tradition and are commonly conducted along the European Atlantic coast. However numerous studies have concluded that intentional transfer of species for aquaculture purposes is one of the most principal vectors for the introduction...

  8. Comparative sensitivity of European native (Anodonta anatina) and exotic (Corbicula fluminea) bivalves to mercury

    Science.gov (United States)

    Oliveira, Patrícia; Lopes-Lima, Manuel; Machado, Jorge; Guilhermino, Lúcia

    2015-12-01

    Pollution is believed to be an important factor modulating the competition between exotic invasive bivalves and their native competitors. Thus, the objective of the present study was to compare the sensitivity of the European native Anodonta anatina and the exotic invasive species Corbicula fluminea to mercury, a ubiquitous environmental contaminant of high concern. In laboratory acute bioassays, adult organisms of both species were exposed independently to mercury for 96 h (31-500 μg/L). The criteria indicative of toxicity were mortality and biomarkers of oxidative stress and damage, neurotoxicity, and energy production changes. Mercury induced mortality in A. anatina (72 h-LC10 and 72 h-LC50 of 14.0 μg/L and 49.6 μg/L, respectively) but not in C. fluminea. The ability of C. fluminea to maintaining the shell closed for considerable periods of time when exposed to high concentrations of mercury and the effective activation (up to 63 μg/L) of mechanisms against the oxidative stress caused by mercury may have contributed to its relatively low sensitivity. In the range of concentrations tested, mercury had no significant effects on the other parameters analysed in C. fluminea. Overall, the findings of the present study, suggest that in real scenarios of competition between C. fluminea and A. anatina populations, the presence of mercury may modulate the process, acting in favour of the exotic species because it is less sensitive to this environmental contaminant than the native bivalve. The results of the present study highlight the need of further investigation on the effects of mercury on the competition between exotic invasive species and their native competitors, especially the effects potentially induced by long-term exposure to low concentrations of this metal, the mechanisms involved in the tolerance to mercury-induced stress, and the potential post-exposure recovery of both exotic invasive and native bivalves. This knowledge is most important for

  9. Filter-feeding bivalves can remove avian influenza viruses from water and reduce infectivity

    OpenAIRE

    Faust, Christina; Stallknecht, David; Swayne, David; Brown, Justin

    2009-01-01

    Avian influenza (AI) viruses are believed to be transmitted within wild aquatic bird populations through an indirect faecal–oral route involving contaminated water. This study examined the influence of filter-feeding bivalves, Corbicula fluminea, on the infectivity of AI virus in water. Clams were placed into individual flasks with distilled water inoculated 1:100 with a low pathogenic (LP) AI virus (A/Mallard/MN/190/99 (H3N8)). Viral titres in water with clams were significantly lower at 24 ...

  10. Epistaxis as the initial manifestation of brucellosis

    OpenAIRE

    Al Mousa, Abdullah I

    2008-01-01

    Brucellosis is a multisystem disease with a broad spectrum of clinical manifestations. Hematologic complications in the form of mild pancytopenia are occasionally reported in the course of acute brucellosis. Rarely, thrombocytopenia is severe and can be associated with purpura and mucosal bleeding. Epistaxis as the initial manifestation of brucellosis is a rarely reported phenomenon. A case of young adult is being reported who presented with epistaxis due to brucellosis-induced thrombocytopenia.

  11. Endocrine disorders and the neurologic manifestations

    OpenAIRE

    Yu, Jeesuk

    2014-01-01

    The nervous system and the endocrine system are closely interrelated and both involved intimately in maintaining homeostasis. Endocrine dysfunctions may lead to various neurologic manifestations such as headache, myopathy, and acute encephalopathy including coma. It is important to recognize the neurologic signs and symptoms caused by the endocrine disorders while managing endocrine disorders. This article provides an overview of the neurologic manifestations found in various endocrine disord...

  12. Augmenting SCORM Manifests with Adaptive Links

    OpenAIRE

    Abdullah, NA; Bailey, CP; Davis, HC

    2004-01-01

    This paper describes an experiment to augment SCORM manifests with adaptive links using AuldLinky in order to promote content reusability, interoperability and personalized e-learning. Our technique involves the automatic deduction of a concept map from a manifest and the transformation of its pertinent elements into FOHM (Fundamental Object Hypermedia Model) objects before augmenting the information with complimentary and adaptive links using AuldLinky.

  13. Skeletal scintigraphy manifestations of hematologic disorders

    International Nuclear Information System (INIS)

    Skeletal manifestations are common in hematologic disorders. Benign entities such as Sickle cell disease develop microvascular embolization causing skeletal crisis. Leukemia, acute myeloblastic or lymphoblastic may develop bone marrow infarcts. Compromised immunity makes them susceptible to secondary infection leading to osteomyelitis or septic arthritis. Exposure to steroids may lead to osteonecrosis in these cases. Presented here is an atlas of various scintigraphic skeletal manifestations encountered over the past 10 years, in hematologic disorders

  14. Rheumatic manifestations of inflammatory bowel disease

    OpenAIRE

    Rodríguez-Reyna, Tatiana Sofía; Martínez-Reyes, Cynthia; Yamamoto-Furusho, Jesús Kazúo

    2009-01-01

    This article reviews the literature concerning rheumatic manifestations of inflammatory bowel disease (IBD), including common immune-mediated pathways, frequency, clinical course and therapy. Musculoskeletal complications are frequent and well-recognized manifestations in IBD, and affect up to 33% of patients with IBD. The strong link between the bowel and the osteo-articular system is suggested by many clinical and experimental observations, notably in HLA-B27 transgenic rats. The autoimmune...

  15. Neurologic Manifestations of Childhood Rheumatic Diseases

    OpenAIRE

    Shiari, Reza

    2012-01-01

    How to Cite this Article: Shiari R. Neurologic Manifestations of Childhood Rheumatic Diseases.  Iran J Child Neurol Autumn 2012; 6(4): 1-7.Children with rheumatic disorders may have a wide variety of clinical features ranging from fever or a simple arthritis to complex multisystem autoimmune diseases. Information about the prevalence of neurological manifestations in children with rheumatologic disorders is limited. This review describes the neurologic complications of childhood Rheumatic dis...

  16. Cutaneous Manifestations in Inflammatory Bowel Diseases

    OpenAIRE

    Simona Roxana Georgescu; Cristina Iulia Mitran; Madalina Irina Mitran; Monica Costescu; Vasile Benea; Maria Isabela Sarbu; Mircea Tampa

    2015-01-01

    Inflammatory bowel diseases have a high frequency in Europe. They are chronic disorders that evolve with relapses and remissions. Clinical features include the signs of underlying inflammatory bowel disease and also signs of extraintestinal manifestations. Cutaneous disorders are the most common extraintestinal manifestations associated with inflammatory bowel diseases, which can be dependent on or independent of gastrointestinal disease activity. The main cutaneous disorders are erythema nod...

  17. Adaptive morphologies and guild structure in a high-diversity bivalve fauna from an early Campanian rocky shore, Ivö Klack (Sweden)

    DEFF Research Database (Denmark)

    Sørensen, Anne Mehlin; Surlyk, Finn; Jagt, John W. M.

    2012-01-01

    The bivalve fauna from a late early Campanian rocky shore at Ivö Klack (southern Sweden), comprises just over sixty species, a very high diversity in comparison to other Late Cretaceous and modern rocky shore bivalve assemblages. This high diversity is here considered to represent a reliable census...... of the fauna; only in part can it be explained by the cumulative effect of generations of bivalves inhabiting this coastal environment. The high density and diversity and the wide range of shell morphologies allow interpretation of different modes of life in this variable environment with many...... from adjacent environments. It includes some of the most northerly known, very small rudistid bivalves, in addition to the oldest known occurrences of Mytilus and Barbatia in association with rocky shores. Bivalves constituted the most important invertebrate group inhabiting the late early Campanian...

  18. Organochlorine pesticides in Piracicaba river basin (São Paulo/Brazil: a survey of sediment, bivalve and fish

    Directory of Open Access Journals (Sweden)

    Daniela Mariano Lopes da Silva

    2008-01-01

    Full Text Available The main objective of this paper was to evaluate the level of occurrence of the organochlorine compounds in samples of sediments, bivalves and two fish species collected in the Piracicaba River basin (São Paulo, Brazil. The isomers alpha and gamma of HCH and Heptachlor were most frequently detected in samples of sediments and specimens of bivalve and fish. Therefore, although the levels of these compounds found were not critically high, they are still found in the environment. This fact suggests that they are still being used, despite the fact that the use of these compounds was outlawed more than twenty years ago.

  19. Evaluation of the effects of candidate molluscicides on two nontarget bivalves

    Science.gov (United States)

    Waller, D.L.; Marking, L.L.; Rach, J.J.

    1992-01-01

    A variety of molluscicides have been proposed for use in control of zebra mussels (Dreissena polymorpha), but their effect on nontarget aquatic organisms has not been evaluated. Standard methods were adapted for assessing the toxicity of candidate molluscicides to two nontarget bivalves. Fingernail clams, Musculium transversum, and the fawnfoot mussel, Truncilla donaciformis, were selected to represent the two families of native bivalves. Test organisms were collected from pools 6 to 9 of the Upper Mississippi River near La Crosse, WI. Static acute toxicity tests were conducted for 48 hours followed by a 96-hour monitoring period in untreated water to more fully assess survival and mortality. Toxicity data were analyzed by probit analysis to give LC sub(50) values and 95% confidence limits. The same chemicals as those tested at Ohio State University were evaluated against zebra mussels. Results from these studies and those conducted at Ohio State University will be used to evaluate the effectiveness of chemicals in zebra mussel control and their potential hazard to nontarget organisms.

  20. Assessing phototoxicity of petroleum using the bivalve Mulinia lateralis and the mysid Mysidopsis bahia

    International Nuclear Information System (INIS)

    One of the major inputs of PAHs in the marine environment is petroleum products. A large and often catastrophic source of petroleum is an oil spill, which releases concentrated quantities of PAHs into the water column. Intermediate molecular weight compounds remain in the water column for a relatively extended length of time. These compounds include phototoxic PAHs such as anthracene, fluoranthene, pyrene, and their substituted derivatives. Assessments of the environmental impact of marine oil spills have not included phototoxicity tests using pelagic larvae of benthic invertebrates. In this study, the photoreactive toxicity of individual PAHs, including anthracene, pyrene, and fluoranthene, were determined using the bivalve, Mulinia lateralis and the mysid, Mysidopsis bahia. Ultraviolet light exposures increased toxicity relative to fluorescent light for both species but a particularly dramatic response was seen using M. lateralis embryos. This species was relatively insensitive when exposed under fluorescent lights, but exhibited up to a 4,000 fold increase in toxicity under ultraviolet lights. Exposures with different types of petroleum (e.g., fuel oil number-sign 2 and crude oil) under fluorescent and ultraviolet light will demonstrate the utility of this bivalve and mysid for assessing oil spill-related acute and sublethal toxicity in the marine environment

  1. Ocean acidification increases cadmium accumulation in marine bivalves: a potential threat to seafood safety

    Science.gov (United States)

    Shi, Wei; Zhao, Xinguo; Han, Yu; Che, Zhumei; Chai, Xueliang; Liu, Guangxu

    2016-01-01

    To date, the effects of ocean acidification on toxic metals accumulation and the underlying molecular mechanism remains unknown in marine bivalve species. In the present study, the effects of the realistic future ocean pCO2 levels on the cadmium (Cd) accumulation in the gills, mantle and adductor muscles of three bivalve species, Mytilus edulis, Tegillarca granosa, and Meretrix meretrix, were investigated. The results obtained suggested that all species tested accumulated significantly higher Cd (p health risk of Cd (based on the estimated target hazard quotients, THQ) via consumption of M. meretrix at pH 7.8 and 7.4 significantly increased 1.21 and 1.32 times respectively, suggesting a potential threat to seafood safety. The ocean acidification-induced increase in Cd accumulation may have occurred due to (i) the ocean acidification increased the concentration of Cd and the Cd2+/Ca2+ in the seawater, which in turn increased the Cd influx through Ca channel; (ii) the acidified seawater may have brought about epithelia damage, resulting in easier Cd penetration; and (iii) ocean acidification hampered Cd exclusion.

  2. Contamination in sediments, bivalves and sponges of McMurdo Sound, Antarctica

    International Nuclear Information System (INIS)

    This study examined the concentrations of total hydrocarbons (THC), polychlorinated biphenyls (PCB), polyaromatic hydrocarbons (PAH), and trace metals (Cu, Zn, Cd, Pb, Hg and As) in marine sediments off Scott Base (NZ) and compared them with sediments near the highly polluted McMurdo Station (US) as well as less impacted sites including Turtle Rock and Cape Evans. The Antarctic mollusc, Laternula elliptica and three common sponge species were also analysed for trace metals. The mean THC concentration in sediments from Scott Base was 3 fold higher than the pristine site, Turtle Rock, but 10 fold lower than samples from McMurdo Station. McMurdo Station sediments also contained the highest concentrations of PAHs, PCBs and the trace metals, Cu, Zn, Pb, Cd and Hg. Copper was significantly higher in bivalves from McMurdo Station than other sites. Trace metal concentrations in sponges were generally consistent within sites but no spatial patterns were apparent. - Analyses of Antarctic marine sediments, bivalves and sponges revealed strong PAH, PCB and trace metal gradients in McMurdo Sound

  3. Traces (ichnospecies Oichnus paraboloides of predatory gastropods on bivalve shells from the Seogwipo Formation, Jejudo, Korea

    Directory of Open Access Journals (Sweden)

    Dal-Yong Kong

    2015-12-01

    Full Text Available Circular to subcircular drill holes were identified on the bivalve shells collected from the Seogwipo Formation, Jejudo, Korea. A great majority of the drill holes (>70% were found on the surfaces of a bivalve species Glycymeris rotunda. They are characterized by a beveled sharp edge and paraboloid in cross section with larger outer borehole diameter (OBD; mean 4.21 mm and smaller inner borehole diameter (mean 2.94 mm. Walls of the drill holes are generally smooth, and walls ornamented with etched relief-like structures were also recognized. A slightly raised central boss observed in an incomplete specimen may indicate a failure of predator’s attack. All drill holes collected are classified as a single ichnospecies Oichnus paraboloides Bromley, 1981. They are interpreted as boring traces produced by predatory gastropods, particularly naticid gastropods. Most O. paraboloides boreholes are observed in the central area of shell surfaces; a few boreholes lie marginally, which may reflect a borehole-site selectivity. No correlation between size of prey (shell height and size of predator (OBD is recognized. It is likely, however, that drilled shells of about 30 mm in height represent optimal prey size for naticid predators that lived in a benthic Seogwipo community.

  4. Bivalve immunity and response to infections: Are we looking at the right place?

    Science.gov (United States)

    Allam, Bassem; Pales Espinosa, Emmanuelle

    2016-06-01

    Significant progress has been made in the understanding of cellular and molecular mediators of immunity in invertebrates in general and bivalve mollusks in particular. Despite this information, there is a lack of understanding of factors affecting animal resistance and specific responses to infections. This in part results from limited consideration of the spatial (and to some extent temporal) heterogeneity of immune responses and very limited information on host-pathogen (and microbes in general) interactions at initial encounter/colonization sites. Of great concern is the fact that most studies on molluscan immunity focus on the circulating hemocytes and the humoral defense factors in the plasma while most relevant host-microbe interactions occur at mucosal interfaces. This paper summarizes information available on the contrasting value of information available on focal and systemic immune responses in infected bivalves, and highlights the role of mucosal immune factors in host-pathogen interactions. Available information underlines the diversity of immune effectors at molluscan mucosal interfaces and highlights the tailored immune response to pathogen stimuli. This context raises fascinating basic research questions around host-microbe crosstalk and feedback controls of these interactions and may lead to novel disease mitigation strategies and improve the assessment of resistant crops or the screening of probiotic candidates. PMID:27004953

  5. A kinetic approach to assess oxidative metabolism related features in the bivalve Mya arenaria.

    Science.gov (United States)

    González, Paula Mariela; Abele, Doris; Puntarulo, Susana

    2012-12-01

    Electron paramagnetic resonance uses the resonant microwave radiation absorption of paramagnetic substances to detect highly reactive and, therefore, short-lived oxygen and nitrogen centered radicals. Previously, steady state concentrations of nitric oxide, ascorbyl radical (A·) and the labile iron pool (LIP) were determined in digestive gland of freshly collected animals from the North Sea bivalve Mya arenaria. The application of a simple kinetic analysis of these data based on elemental reactions allowed us to estimate the steady state concentrations of superoxide anion, the rate of A· disappearance and the content of unsaturated lipids. This analysis applied to a marine invertebrate opens the possibility of a mechanistic understanding of the complexity of free radical and LIP interactions in a metabolically slow, cold water organism under unstressed conditions. This data can be further used as a basis to assess the cellular response to stress in a simple system as the bivalve M. arenaria that can then be compared to cells of higher organisms. PMID:22829190

  6. Bivalve Omics: State of the Art and Potential Applications for the Biomonitoring of Harmful Marine Compounds

    Directory of Open Access Journals (Sweden)

    Paola Venier

    2013-11-01

    Full Text Available The extraordinary progress experienced by sequencing technologies and bioinformatics has made the development of omic studies virtually ubiquitous in all fields of life sciences nowadays. However, scientific attention has been quite unevenly distributed throughout the different branches of the tree of life, leaving molluscs, one of the most diverse animal groups, relatively unexplored and without representation within the narrow collection of well established model organisms. Within this Phylum, bivalve molluscs play a fundamental role in the functioning of the marine ecosystem, constitute very valuable commercial resources in aquaculture, and have been widely used as sentinel organisms in the biomonitoring of marine pollution. Yet, it has only been very recently that this complex group of organisms became a preferential subject for omic studies, posing new challenges for their integrative characterization. The present contribution aims to give a detailed insight into the state of the art of the omic studies and functional information analysis of bivalve molluscs, providing a timely perspective on the available data resources and on the current and prospective applications for the biomonitoring of harmful marine compounds.

  7. Prevalence of cutaneous manifestations of diabetes mellitus

    International Nuclear Information System (INIS)

    Diabetes mellitus (DM) is a clinical syndrome characterized by hyperglycaemia due to absolute or relative insulin deficiency. The aim of this study was to evaluate the frequency of skin manifestations in patients with diabetes mellitus of this area. This descriptive study was conducted in medical out patient door of District Headquarter Hospital Battgram from January 2008 to July 2008. A total of 350 diabetic (types 1 and 2) patients over 15 years of age attending the medical OPD of DHQ Hospital were examined in detail for skin manifestations of the disease. Three hundred and fifty diabetic (type-1 and type-2) patients (193 females and 157 males) enrolled in this study. Mean age of the patients was 54+-8.53 years. Duration of diabetes was between 1-12 years; 320 patients had type-2 and 30 patients had type-1 diabetes mellitus. Patients with uncontrolled disease were 327 and 23 patients showed adequate glycaemic control. Seventy-six percent of patients had cutaneous manifestations. The skin manifestations observed were: skin infections 30.9%, foot gangrene and ulcers 12.9%, pruritus 7.1%, vitiligo 5.7%, yellow skin 4.2%, diabetic dermopathy 4.2%, skin tags 3.7%, acanthosis nigricans 2.9%, eruptive xanthomas 2.6%, necrobiosis lipoidica diabeticorum 1.4%, diabetic bullae 0.6%, and pigmented purpuras in 0.3% patients. Cutaneous manifestations were quite Common in the diabetics of this area. (author)

  8. Discours manifestant et contestation universitaire (2009)

    OpenAIRE

    Grinshpun, Yana

    2013-01-01

    Au cours du deuxième semestre 2009 l’université française connaît une grève quasi générale accompagnée par une série de manifestations. La manifestation est une situation de communication qu’on peut appréhender à la fois comme construction d’une communauté de conviction transitoire et comme espace de production et de « monstration » d’énoncés oraux et écrits. Dix manifestations contre les réformes de l’université et de la formation des maîtres, organisées dans la région parisienne, ont mis en...

  9. Cutaneous manifestations of systemic lupus erythematosus.

    Science.gov (United States)

    Uva, Luís; Miguel, Diana; Pinheiro, Catarina; Freitas, João Pedro; Marques Gomes, Manuel; Filipe, Paulo

    2012-01-01

    Systemic lupus erythematosus (SLE) is a multiorgan autoimmune disease of unknown etiology with many clinical manifestations. The skin is one of the target organs most variably affected by the disease. The American College of Rheumatology (ACR) established 11 criteria as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individuals and do not do well in that capacity. Cutaneous lesions account for four of these 11 revised criteria of SLE. Skin lesions in patients with lupus may be specific or nonspecific. This paper covers the SLE-specific cutaneous changes: malar rash, discoid rash, photosensitivity, and oral mucosal lesions as well as SLE nonspecific skin manifestations, their pathophysiology, and management. A deeper thorough understanding of the cutaneous manifestations of SLE is essential for diagnosis, prognosis, and efficient management. Thus, dermatologists should cooperate with other specialties to provide optimal care of SLE patient. PMID:22888407

  10. Cutaneous Manifestations of Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Luís Uva

    2012-01-01

    Full Text Available Systemic lupus erythematosus (SLE is a multiorgan autoimmune disease of unknown etiology with many clinical manifestations. The skin is one of the target organs most variably affected by the disease. The American College of Rheumatology (ACR established 11 criteria as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individuals and do not do well in that capacity. Cutaneous lesions account for four of these 11 revised criteria of SLE. Skin lesions in patients with lupus may be specific or nonspecific. This paper covers the SLE-specific cutaneous changes: malar rash, discoid rash, photosensitivity, and oral mucosal lesions as well as SLE nonspecific skin manifestations, their pathophysiology, and management. A deeper thorough understanding of the cutaneous manifestations of SLE is essential for diagnosis, prognosis, and efficient management. Thus, dermatologists should cooperate with other specialties to provide optimal care of SLE patient.

  11. Vertigo as a Predominant Manifestation of Neurosarcoidosis

    Directory of Open Access Journals (Sweden)

    Tasnim F. Imran

    2015-01-01

    Full Text Available Sarcoidosis is a granulomatous disease of unknown etiology that affects multiple organ systems. Neurological manifestations of sarcoidosis are less common and can include cranial neuropathies and intracranial lesions. We report the case of a 21-year-old man who presented with vertigo and uveitis. Extensive workup including brain imaging revealed enhancing focal lesions. A lacrimal gland biopsy confirmed the diagnosis of sarcoidosis. The patient was initially treated with prednisone, which did not adequately control his symptoms, and then was switched to methotrexate with moderate symptomatic improvement. Our patient had an atypical presentation with vertigo as the predominant manifestation of sarcoidosis. Patients with neurosarcoidosis typically present with systemic involvement of sarcoidosis followed by neurologic involvement. Vertigo is rarely reported as an initial manifestation. This case highlights the importance of consideration of neurosarcoidosis as an entity even in patients that may not have a typical presentation or systemic involvement of disease.

  12. Influence of incubation conditions on the anoxic survival of marine bivalves. Static and semi-static incubations

    NARCIS (Netherlands)

    De Zwaan, A.; Cattani, O.; Vitali, G.; Cortesi, P.

    2001-01-01

    In a comparative study of 4 bivalve species we show that the apparent widely different tolerances in survival time observed in a closed system filled with N-2-gassed seawater is mainly due to the experimental conditions. Both a high dose of cadmium and the antibiotic chloramphenicol increase surviva

  13. Assessment of Heavy Metals in Bivalves Molluscs of Apulian Region: a 3-years control activity of a EU Laboratory

    Directory of Open Access Journals (Sweden)

    Miedico O.

    2013-04-01

    Full Text Available The bivalve molluscs represent an important matrix to be studied for several reasons. Their nutritional properties make them valuable to the consumers, so that their consumption and commercial value has risen worldwide. Simultaneously, their significant water-filtering capability and their persistence in the same place make them good bio-indicators of marine ecosystems. The presence of the heavy metal contaminants, as Cd, Pb and Hg, was investigated in bivalve molluscs such as mussels (Mytilus galloprovincialis, clams (Venus gallina and oysters (Ostrea edulis. In the present study, a survey was carried out on 334 samples addressed to the Istituto Zooprofilattico Sperimentale – Puglia e Basilicata, Foggia (ITALY between 2009-2011, and collected by official authorities along the coasts of Apulia Region. The conformity of heavy metal content in bivalve molluscs was verified, in according to EC Reg. 1881/2006. The compliance was found for the total amount of samples. The obtained data on heavy metals concentration in bivalve molluscs were compared with data found in monitoring studies on the incidence of heavy metals in 1981 in North-Western Mediterranean Sea, in 2003 in Tyrrhenian Sea and in 2010 in Pacific Ocean (Chile, reported in literature. The information obtained from this work offer an essential database, not only for the authorities involved in food control, but also for the official institutions responsible of a constant control of the marine ecosystem pollution.

  14. A striking parallel between cardiolipin fatty acid composition and phylogenetic belonging in marine bivalves: a possible adaptative evolution?

    Science.gov (United States)

    Kraffe, E; Grall, J; Le Duff, M; Soudant, P; Marty, Y

    2008-10-01

    Thirty-five species of marine mollusk bivalves were analyzed for their fatty acid (FA) composition of cardiolipin (Ptd(2)Gro). All species showed a Ptd(2)Gro with strong selectivity for only a few polyunsaturated fatty acids, but three characteristic FA profiles emerged, with clear parallels to bivalve phylogeny. A first group of 12 species belonging to the Eupteriomorphia subgroup (Filibranchia) was characterized by a Ptd(2)Gro almost exclusively composed of 22:6n-3, whereas in the four Filibranchia Pteriomorph species analyzed, this FA was combined with substantial proportions of 18:2n-6 and 18:3n-3. Finally, a third group of 20 species, all belonging to the Heterodonta subclass, possessed Ptd(2)Gro containing predominantly both 22:6n-3 and 20:5n-3. Polyunsaturated FA moieties and arrangements in the Ptd(2)Gro of some marine species investigated in other classes of the mollusk phylum (Gastropoda, Polyplacophora) were found to be different. The present results suggest that the specific Ptd(2)Gro FA compositions in bivalves are likely to be controlled and conserved in species of the same phylogenetic group. Functional significances of the evolution of this mitochondrial lipid structure in bivalves are discussed. PMID:18716818

  15. Relationship of Parasites and Pathologies to Contaminant Body Burden in Sentinel Bivalves: NOAA Status and Trends `Mussel Watch? Program

    OpenAIRE

    Kim, Yungkul; Powell, Eric N.; Wade, Terry L.; Presley, Bobby J.

    2008-01-01

    Relationship of Parasites and Pathologies to Contaminant Body Burden in Sentinel Bivalves: NOAA Status and Trends `Mussel Watch? Program correspondence: Corresponding author. (Kim, Yungkul) (Kim, Yungkul) Haskin Shellfish Research Laboratory Rutgers University 6959 Miller Ave Port Norris NJ 08349-3167 - (Kim, Yungkul) UNITED STATES (Kim, Yungkul) Haskin Shellfish Research Laboratory Rutgers University 6959 Miller ...

  16. Studies on the causes of mortality of the estuarine bivalve Macoma balthica under conditions of (near) anoxia

    NARCIS (Netherlands)

    De Zwaan, A.; Babarro, J.M.F.

    2001-01-01

    Survival of the bivalve Macoma balthica in (near) anoxic seawater was studied in a static system and a flow-through system and compared with emersed exposure to air and NZ In the static system, a decrease in pH and exponential accumulation of sulphide in the incubation medium were observed, indicati

  17. Main Ocular Manifestations in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Sandra Saray Quignon Santana

    2009-12-01

    Full Text Available Rheumatoid arthritis is considered an autoimmune disease in which articular and extra articular manifestations are produced and contribute to alter the functional capacity of the individual. This study consists on performing a bibliographical review showing the main ocular manifestations in patients with rheumatoid arthritis. It is our purpose to give you our experiences to the students as well as the internal medicine, ophthalmology and rheumatologist residents about this topic. The ophthalmological consultation of sick patients contributes to the prevention of ocular illnesses which are characteristic of the base disease and improve the ocular health.

  18. Lupus as a paraneoplastic manifestation of cholangiocarcinoma.

    Science.gov (United States)

    González Amores, Yolanda; Hernando Rebollar, Sofía; Casado Bernabeu, Aida

    2016-05-01

    Tumors originating in the digestive system, like those in other areas, whether solid or otherwise, may present with extradigestive manifestations in the setting of a paraneoplastic syndrome. Systemic lupus erythematosus (SLE) is an autoimmune condition most commonly involving women of childbearing age. On occasion it represents a paraneoplastic manifestation heralding a primary tumor. Cancer suspicion is therefore a key element for newly diagnosed SLE cases with nonstandard epidemiology even in the absence of suggestive symptoms, and digestive tumors should be included in the differential diagnosis. PMID:26925842

  19. Alagille syndrome with prominent skin manifestations

    Directory of Open Access Journals (Sweden)

    Das Jayanta

    2005-03-01

    Full Text Available Alagille syndrome, a rare genetic disorder with autosomal dominant transmission, manifests 5 major features: paucity of interlobular bile ducts, characteristic facies, posterior embryotoxon, vertebral defects and peripheral pulmonic stenosis. We report a 6-year-old male child who presented with a history of progressive jaundice since infancy, generalized pruritus and widespread cutaneous xanthomata. He was also found to have obstructive jaundice, pulmonary stenosis with ventricular septal defect and paucity of bile ducts in liver biopsy. Histopathology confirmed skin lesions as xanthomata. The child was diagnosed as a case of Alagille syndrome. This particular syndrome with prominent cutaneous manifestations has been rarely reported in the Indian literature.

  20. The Ghost in the Shell : Local and Remote Forcing of a Coastal Bivalve Inhabiting the Humboldt Current System

    Science.gov (United States)

    Gosselin, M.

    2014-12-01

    The external skeleton of mollusc bivalves, the shell, can furnish a recording of the environmental changes to which the organisms and population are exposed during their lives. The bivalve's growth is subjected to the thermocline variability; which itself is affected by environmental and climatic events. A highly variable environment such as the Humboldt current system (HCS) requires tools capable of recording its variations over a wide range of periodicities. Upwelling, Coastal trapped waves (CTWs), El Niño Southern Oscillation, and Pacific decadal oscillation events contribute to this environmental and climatic variability. The thermocline depth is modified by these different events at their own time-scales (respectively, daily to weekly, intraseasonally, interseasonally to interannually, and on a decadal scale). The thermocline variation translates into changes in Sea surface temperature (SST) and in the qualitative and quantitative productivity of phytoplankton. These two environmental factors are critical to bivalve growth.The sclerochronological (increment width) and sclerochemical (δ18O and δ13C) study consisted on the analysis of the Chilean bivalve Eurhomalea rufa, collected in 2005, as a recorder of the environmental HCS variability. The calibration step identified daily, monthly, and annual marks in the growth patterns of E. rufa. The results confirmed that the thermocline variability mainly drives the bivalve's activity and led to the establishment of a paleotemperature equation. Moreover, periodogram and wavelet analyses exposed the respective impacts of each environmental event from daily to interannual periodicities. In particular, the growth pattern of E. rufa follows SST variability at an intraseasonal periodicity (~ 60 days) which is remotely induced by CTWs. CTWs are generated by Kelvin oceanic waves, which are formed primarily by eastward equatorial Pacific winds (e.g. Shaffer et al. 1997; Montecino and Lange 2009).Sclerochronological studies

  1. Forming nacreous layer of the shells of the bivalves Atrina rigida and Pinctada margaritifera: An environmental- and cryo-scanning electron microscopy study

    OpenAIRE

    Nudelman, Fabio; Shimoni, Eyal; Klein, Eugenia; Rousseau, Marthe; Bourrat, Xavier; Lopez, Evelyne; Addadi, Lia; Weiner, Steve

    2008-01-01

    International audience A key to understanding control over mineral formation in mollusk shells is the microenvironment inside the pre-formed 3-dimensional organic matrix framework where mineral forms. Much of what is known about nacre formation is from observations of the mature tissue. Although these studies have elucidated several important aspects of this process, the structure of the organic matrix and the microenvironment where the crystal nucleates and grows are very difficult to inf...

  2. Short and long term consequences of larval stage exposure to constantly and ephemerally elevated carbon dioxide for marine bivalve populations

    Directory of Open Access Journals (Sweden)

    C. J. Gobler

    2012-11-01

    Full Text Available While larval bivalves are highly sensitive to ocean acidification, the basis for this sensitivity and the longer term implications of this sensitivity are unclear. Experiments were performed to assess the short term (days and long term (months consequences of larval stage exposure to varying CO2 concentrations for calcifying bivalves. Higher CO2 concentrations depressed both calcification rates assessed using 45Ca uptake and RNA:DNA ratios in Mercenaria mercenaria and Argopecten irradians larvae with RNA:DNA ratios being highly correlated with larval growth rates r2 > 0.9. These findings suggested that high CO2 has a cascading negative physiological impact on bivalve larvae stemming in part from lower calcification rates. Exposure to elevated CO2 during the first four days of larval development significantly depressed A. irradians larval survival rates, while a 10 day exposure later in larval development did not, demonstrating the extreme CO2-sensitivity of bivalve larvae during first days of development. Short- (weeks and long-term (10 month experiments revealed that individuals surviving exposure to high CO2 during larval development grew faster when exposed to normal CO2 as juveniles compared to individuals reared under ambient CO2 as larvae. These increased growth rates could not, however, overcome size differences established during larval development, as size deficits of individuals exposed to even moderate levels of CO2 as larvae were evident even after 10 months of growth under normal CO2 concentrations. This `legacy effect' emphasizes the central role larval stage CO2 exposure can play in shaping the success of modern day bivalve populations.

  3. Influences of organic matter and calcification rate on trace elements in aragonitic estuarine bivalve shells

    Science.gov (United States)

    Takesue, Renee K.; Bacon, Charles R.; Thompson, Janet K.

    2008-11-01

    A suite of elements (B, Na, Mg, S, K, Ca, V, Mn, Cr, Sr, and Ba) was measured in aragonitic shells of the estuarine bivalve Corbula amurensis, the Asian clam, using the Sensitive High-Resolution Ion MicroProbe with Reverse Geometry (SHRIMP RG). Our initial intent was to explore potential geochemical proxy relationships between shell chemistry and salinity (freshwater inflow) in northern San Francisco Bay (SFB). In the course of this study we observed variations in shell trace element to calcium ([M]/Ca) ratios that could only be attributed to internal biological processes. This paper discusses the nature and sources of internal trace element variability in C. amurensis shells related to the shell organic fraction and shell calcification rates. The average organic content of whole C. amurensis shells is 19%. After treating whole powdered shells with an oxidative cleaning procedure to remove organic matter, shells contained on average 33% less total Mg and 78% less total Mn. Within our analytical uncertainty, Sr and Ba contents were unchanged by the removal of organic matter. These results show that aragonitic C. amurensis shells have a large component of non-lattice-bound Mg and Mn that probably contribute to the dissimilarity of [M]/Ca profiles among five same-sized shells. Non-lattice-bound trace elements could complicate the development and application of geochemical proxy relationships in bivalve shells. Because B, Ba and Sr occur exclusively in shell aragonite, they are good candidates for external proxy relationships. [M]/Ca ratios were significantly different in prismatic and nacreous aragonite and in two valves of the same shell that had different crystal growth rates. Some part of these differences can be attributed to non-lattice-bound trace elements associated with the organic fraction. The differences in [M]/Ca ratios were also consistent with the calcification rate-dependent ion transport model developed by Carré et al. [Carré M., Bentaleb I

  4. A Large Metabolic Carbon Ccontribution to the δ13C Record in Marine Aragonitic Bivalve Shells

    Science.gov (United States)

    Gillikin, D. P.; Lorrain, A.; Dehairs, F.

    2006-12-01

    The stable carbon isotopic signature archived in bivalve shells was originally thought to record the δ13C of seawater dissolved inorganic carbon (δ13C-DIC). However, more recent studies have shown that the incorporation of isotopically light metabolic carbon (M) significantly affects the δ13C signal recorded in biogenic carbonates. To assess the M contribution to Mercenaria mercenaria shells collected in North Carolina, USA, we sampled seawater δ13C-DIC, tissue, hemolymph and shell δ13C. We found up to a 4‰ decrease through ontogeny in shell δ13C in a 23 year old individual. There was no correlation between shell height or age and tissue δ13C. Thus, the ontogenic decrease observed in the shell δ13C could not be attributed to changes in food sources as the animal ages leading to more negative metabolic CO2, since this would require a negative relationship between tissue δ13C and shell height. Hemolymph δ13C, on the other hand, did exhibit a negative relationship with height, but the δ13C values were more positive than expected, indicating that hemolymph may not be a good proxy of extrapallial fluid δ13C. Nevertheless, the hemolymph data indicate that respired CO2 does influence the δ13C of internal fluids and that the amount of respired CO2 is related to the age of the bivalve. The percent metabolic C incorporated into the shell (%M) was significantly higher (up to 37%) than has been found in other bivalve shells, which usually contain less than 10 %M. Attempts to use shell biometrics to predict %M could not explain more than ~60% of the observed variability. Moreover, there were large differences in the %M between different sites. Thus, the metabolic effect on shell δ13C cannot easily be accounted for to allow reliable δ13C-DIC reconstructions. However, there does seem to be a common effect of size, as all sites had indistinguishable slopes between the %M and shell height (+0.19% per mm of shell height).

  5. Morphology and ecology of bivalve molluscs from Admiralty Bay, King George Island, Antarctica

    Directory of Open Access Journals (Sweden)

    Theresinha M. Absher

    1998-08-01

    Full Text Available Bivalve species were collected from shallow coastal areas of King George Island (Martel, Mackellar and Ezcurra Inlets of Admiralty Bay. Twenty one species belonging to 16 genera and 12 families were identified and their morphometric and morphological shell characteristics were described. Three main characteristics were found to be common to the majority of the bivalve species sampled: 1 thin fragile shells; 2 small size of individuals (76%, and 3 the lack of true cardinal teeth (72%. Comparison of calcium data from a tropical estuary and a subantarctic coastal shallow area suggested that the calcium in the sea water was not a constraint to shell building but shell thickness could be an adaptation to the efficiency of energy partitioning. Small individual size and the lack of true cardinal teeth are discussed in relation to a high deposition environment and widespread mud bottoms.Espécies de bivalves foram coletadas na região costeira rasa da Ilha Rei George (Enseadas Martel, Mackellar e Ezcurra da Baía do Almirantado. Vinte e uma espécies pertencentes a 16 gêneros e 12 famílias foram identificadas e as caractrísticas morfológicas e morfométricas das conchas descritas. Destacaram-se 3 características principais comuns à maioria das espécies: 1 conchas finas e frágeis; 2 pequeno tamanho dos indivíduos (76%, e 3 a ausência de dentes cardinais (72%. A comparação entre os dados de cálcio de um estuário tropical e uma região rasa costeira subantártica sugeriu que os valores de cálcio na água do mar não seriam uma restrição à formação das conchas, mas a espessura das conchas poderia ser uma adaptação à eficiência na distribuição da energia. Discute-se a ausência de dentes cardinais e pequeno tamanho dos indivíduos em ralação a um ambiente de alta deposição e abundância de fundos lodosos.

  6. Unusual thoracic manifestation of metastatic malignant melanoma

    Directory of Open Access Journals (Sweden)

    Mohan K

    2010-01-01

    Full Text Available Massive pleural effusion due to metastatic malignant melanoma is rare. We report a case of bilateral (massive on left side pleural effusion as a metastatic manifestation of cutaneous malignant melanoma. In our case, successful outcome of pleurodesis with vincristine is significant as this agent is rarely used.

  7. CT manifestations of pulmonary Langerhans cell histiocytosis

    International Nuclear Information System (INIS)

    Objective: To analyzes the CT manifestations of pulmonary Langerhans cell histiocytosis (PLCH). Methods: CT features of 11 patients with PLCH proved pathologically were analyzed retrospectively. Results: The main findings in 11 PLCHs were cysts and nodules. Two cases only had cysts, and 1 only had nodules, which most had cavitations. The other 8 cases showed cysts and nodules with 4 cases mainly manifested with cysts and nine mainly manifested with nodules. Two cases had pulmonary interstitial changes. One case only had cysts in the left upper lung field and 10 cases had lesions not only in the upper and middle but in the lower lung field, which 2 cases had more lesions in the lower and costo-phrenic angle field and 8 cases had less lesions in the costo-phrenic angle field. Three of these 8 cases had more lesions in the superior lobe and apical segment of lower lobe. Conclusion: CT manifestations of PLCH are helpful for the early diagnosis. (authors)

  8. Monogenic Autoinflammatory Diseases: Concept And Clinical Manifestations

    OpenAIRE

    de Jesus, Adriana Almeida; Goldbach-Mansky, Raphaela

    2013-01-01

    The objectives of this review are to describe the clinical manifestations of the growing spectrum of monogenic autoinflammatory diseases including recently described syndromes. The autoinflammatory diseases can be grouped based on clinical findings: 1. the three classic hereditary “periodic fever syndromes”, familial Mediterranean Fever (FMF); TNF receptor associated periodic syndrome (TRAPS); and mevalonate kinase deficiency/hyperimmunoglobulinemia D and periodic fever synd...

  9. Gestural Manifestation of Knowledge in Conceptual Frames

    Science.gov (United States)

    Chui, Kawai

    2012-01-01

    Frames are cognitive structures of knowledge grounded in people's social interaction in recurrent sociocultural activities or individual incidences. Discussion concerning the knowledge in frames largely focuses on its linguistic manifestation with regard to roles and role relations in scenes. Little attention has been paid to the scriptal…

  10. Efeito de diferentes temperaturas de armazenamento na qualidade de moluscos bivalves vivos

    OpenAIRE

    Torres, Joana Paula Marques Pinheiro, 1987-

    2011-01-01

    A amêijoa-macha (Venerupis pullastra) é um dos bivalves mais consumidos em Portugal. No presente estudo foi avaliada a qualidade microbiológica desta amêijoa capturada na Trafaria através do controle do pH e da contagem de microorganismos indicadores de poluição fecal, tais como Enterobacteriaceae e indicadores de degradação como as bactérias ácido-lácticas, microrganismos viáveis totais e bactérias produtoras de H2S. A amêijoa foi armazenada a diferentes temperaturas (4ºC, 9ºC), e avaliou-se...

  11. Physiological status and intersex in the endobenthic bivalve Scrobicularia plana from thirteen estuaries in northwest France.

    Science.gov (United States)

    Tankoua, O Fossi; Amiard-Triquet, C; Denis, F; Minier, C; Mouneyrac, C; Berthet, B

    2012-08-01

    The bivalve Scrobicularia plana, an important species for the structure and functioning of estuarine and coastal mudflats, was studied in thirteen sites from NW France differing by their degree of contamination to document the presence of reproduction impairments (intersex, sex ratio, gonadosomatic indices) in relation to the condition revealed by using hepatosomatic and condition indices. In agreement with recent studies in other European estuaries, intersex was revealed in all the studied estuaries, including sites the chemical and ecological status of which is considered "good" according to the criteria of the European Water Framework Directive. The presence of endocrine disrupting chemicals (EDCs) could result in such disturbances. Our results re-inforce the concern linked to the subtle effects of EDCs, which are active at very low doses, often in the absence of any major sign of toxicity. However at this stage, no clear link may be established between intersex and population effects. PMID:22537660

  12. Influence of an altered salinity regime on the population structure of two infaunal bivalve species

    Science.gov (United States)

    McLeod, Rebecca J.; Wing, Stephen R.

    2008-07-01

    Hydrological alterations in watersheds have changed the flows of freshwater to many nearshore marine environments. The ensuing alterations to the salinity environment of coastal waters may have implications for species distribution. This study describes the response of two common bivalves to a modified salinity environment imposed by freshwater inputs from a hydroelectric power station in Doubtful Sound, New Zealand. Populations of Austrovenus stutchburyi and Paphies australis inhabiting river deltas near the outflow of the power station in inner Doubtful Sound were more than an order of magnitude smaller in abundance than populations in neighbouring Bradshaw Sound where the salinity regime is unaltered. In addition, there was a lack of small size classes of both species in inner Doubtful Sound, suggesting that these populations are unsustainable over the long term (10-20 years). Laboratory experiments demonstrated that sustained exposure (>30 days) to low salinity (food webs of Fiordland's shallow soft sediment communities.

  13. Trace metals in bivalves and seagrass collected from Venezuelan coastal sites

    International Nuclear Information System (INIS)

    Ti vela mactroides and Crassostrea rhizophorae are two abundant species of bivalves along the Venezuelan coast and high local demand as seafood. The seagrass Thalassia testudinum, of interest in different parts of the world, is very abundant in coastal areas of Venezuela. The concentrations of Cd, Cr, Cu, Ni, V and Zn are reported in samples of soft tissue of Tivela mactroides and Crassostrea rhizophorae and tissues of Thalassia testudinum, collected along the Venezuelan coast. These metal concentrations were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Statistical analysis (one-way ANOVA) indicated that the species under consideration have different characteristics compared to metal bioaccumulation and could be used as potential indicators to investigate contamination by trace metals. (author)

  14. Structural characterization and mechanical behavior of a bivalve shell (Saxidomus purpuratus)

    International Nuclear Information System (INIS)

    The structure and mechanical behavior of Saxidomus purpuratus bivalve shell were investigated. XRD results show that the only form of calcium carbonate present in the shell is aragonite. The inner and middle layers have a cross-lamellar structure, while the outer layer has porosity and does not have tiles, but instead has 'blocky' regions. The hardness of middle and inner layer are close in both plane view and cross section, but the hardness of outer layer is significantly less, especially in the plane view. The compressive strengths with loading along the three orientations were established and significant differences were found. The Weibull strength at 50% of the probability of failure varies between 59 and 148 MPa and is dependent on the loading orientation and in condition of shell (dry vs. hydrated). These differences are interpreted in terms of the anisotropic structure and coarser structure of the external layer.

  15. An ecosystem-based approach and management framework for the integrated evaluation of bivalve aquaculture impacts

    DEFF Research Database (Denmark)

    Cranford, Peter J.; Kamermans, Pauline; Krause, Gesche;

    2012-01-01

    -Impact-Response (DPSIR) management framework incorporates the connectivity between human and ecological issues and would permit available performance indicators to be identified and organized in a manner that facilitates different regulatory needs. Suitable performance indicators and modeling approaches, which are used...... to assess DPSIR framework components, are reviewed with a focus on the key environmental issues associated with bivalve farming. Indicator selection criteria are provided to facilitate constraining the number of indicators within the management framework. It is recommended that an ecosystem...... mitigation measures prior to reaching an unacceptable ecological state. We provide an example of a tiered monitoring program that would communicate knowledge to decision-makers on ecosystem State Change and Impact components of the DPSIR framework...

  16. 77 FR 54818 - Polychlorinated Biphenyls (PCBs): Revisions to Manifesting Regulations

    Science.gov (United States)

    2012-09-06

    ... AGENCY 40 CFR Part 761 RIN 2050-AG71 Polychlorinated Biphenyls (PCBs): Revisions to Manifesting... manifesting requirements for PCBs under TSCA to the manifesting requirements for hazardous waste under RCRA... bring into alignment, as much as possible, the manifesting requirements for PCBs to those of...

  17. 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. PMID:25483846

  18. Clarifying phylogenetic relationships and the evolutionary history of the bivalve order Arcida (Mollusca: Bivalvia: Pteriomorphia).

    Science.gov (United States)

    Combosch, David J; Giribet, Gonzalo

    2016-01-01

    The systematics of the bivalve order Arcida constitutes an unresolved conundrum in bivalve systematics. The current definition of Arcida encompasses two superfamilies: Limopsoidea, which includes the recent families Philobryidae and Limopsidae, and Arcoidea, which encompasses the families Arcidae, Cucullaeidae, Noetiidae, Glycymerididae and Parallelodontidae. This classification, however, is controversial particularly with respect to the position and taxonomic status of Glycymerididae. Previous molecular phylogenies were limited either by the use of only a single molecular marker or by including only a few limopsoid and glycymeridid taxa. The challenging nature of Arcida taxonomy and the controversial results of some of the previous studies, prompted us to use a broad range of taxa (55 species), three nuclear markers (18S rRNA, 28S rRNA and histone H3) and a wide range of algorithmic approaches. This broad but stringent approach led to a number of results that differ significantly from previous studies. We provide the first molecular evidence that supports the separation of Arcoidea from Limopsoidea, although the exact position of Glycymerididae remains unresolved, and the monophyly of Limopsoidea is algorithm-dependent. In addition, we present the first time-calibrated evolutionary tree of Arcida relationships, indicating a significant increase in the diversification of arcidan lineages at the beginning of the Cretaceous, around 140Ma. The monophyly of Arcida, which has been supported previously, was confirmed in all our analyses. Although relationships among families remain somehow unresolved we found support for the monophyly of most arcidan families, at least under some analytical conditions (i.e., Glycymerididae, Noetiidae, Philobryidae, and Limopsidae). However, Arcidae, and particularly Arcinae, remain a major source of inconsistency in the current system of Arcida classification and are in dire need of taxonomic revision. PMID:26427825

  19. A large metabolic carbon contribution to the δ 13C record in marine aragonitic bivalve shells

    Science.gov (United States)

    Gillikin, David P.; Lorrain, Anne; Meng, Li; Dehairs, Frank

    2007-06-01

    It is well known that the incorporation of isotopically light metabolic carbon (C M) significantly affects the stable carbon isotope (δ 13C) signal recorded in biogenic carbonates. This can obscure the record of δ 13C of seawater dissolved inorganic carbon (δ 13C DIC) potentially archived in the shell carbonate. To assess the C M contribution to Mercenaria mercenaria shells collected in North Carolina, USA, we sampled seawater δ 13C DIC, tissue, hemolymph and shell δ 13C. All shells showed an ontogenic decrease in shell δ 13C, with as much as a 4‰ decrease over the lifespan of the clam. There was no apparent ontogenic change in food source indicated by soft tissue δ 13C values, therefore a change in the respired δ 13C value cannot be the cause of this decrease. Hemolymph δ 13C, on the other hand, did exhibit a negative relationship with shell height indicating that respired CO 2 does influence the δ 13C value of internal fluids and that the amount of respired CO 2 is related to the size or age of the bivalve. The percent metabolic C incorporated into the shell (%C M) was significantly higher (up to 37%, with a range from 5% to 37%) than has been found in other bivalve shells, which usually contain less than 10%C M. Interestingly, the hemolymph did contain less than 10%C M, suggesting that complex fractionation might occur between hemolymph and calcifying fluids. Simple shell biometrics explained nearly 60% of the observed variability in %C M, however, this is not robust enough to predict %C M for fossil shells. Thus, the metabolic effect on shell δ 13C cannot easily be accounted for to allow reliable δ 13C DIC reconstructions. However, there does seem to be a common effect of size, as all sites had indistinguishable slopes between the %C M and shell height (+0.19% per mm of shell height).

  20. Strong biological controls on Sr/Ca ratios in aragonitic marine bivalve shells

    Science.gov (United States)

    Gillikin, David Paul; Lorrain, Anne; Navez, Jacques; Taylor, James W.; André, Luc; Keppens, Eddy; Baeyens, Willy; Dehairs, Frank

    2005-05-01

    It is well known that skeletal remains of carbonate secreting organisms can provide a wealth of information about past environments. Sr/Ca ratios have been successfully used as a temperature proxy in corals and sclerosponges. Previous work on aragonitic bivalve shells has not been conclusive but suggests a major control of growth rate on Sr/Ca ratios. As many studies have used bivalve growth rates to determine temperature, we tested if Sr/Ca ratios could predict temperature through its relationship with growth rate. Shells from the two species of clams from the same family (veneroidea) studied here, Saxidomus giganteus and Mercenaria mercenaria, show vastly different seasonal Sr/Ca profiles. A strong relationship between average annual Sr/Ca ratios and annual growth rate was found in S. giganteus shells from both Washington (R2 = 0.87) and Alaska (R2 = 0.64), USA, but not in M. mercenaria shells from North Carolina, USA. Furthermore, the Sr/Ca-growth rate relationship was also evident upon a more detailed inspection of subannual growth rates in S. giganteus (R2 = 0.73). Although there were significant positive correlations between Sr/Ca ratios and temperature in S. giganteus shells, the correlations were weak (0.09 control in either clam species, since thermodynamics predict a negative correlation between Sr/Ca ratios and temperature in aragonite. This points toward dominance of biological processes in the regulation of Sr2+. This is also reflected by the largely differing Sr/Ca partition coefficients (DSr) in these shells (DSr ≈ 0.25), when compared to inorganic, coral, and sclerosponge studies (DSr ≈ 1), all of which show a negative dependence of Sr/Ca on temperature. We suggest that caution be taken when using Sr/Ca in any biogenic aragonite as a temperature proxy when the DSr greatly deviates from one, as this indicates the dominance of biological controls on Sr/Ca ratios.

  1. Impact of seawater carbonate chemistry on the calcification of marine bivalves

    Science.gov (United States)

    Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

    2015-07-01

    Bivalve calcification, particularly of the early larval stages, is highly sensitive to the change in ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no effects and [HCO3-] and pH had only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. An equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the mechanisms that limit or facilitate adaptation to future ocean acidification, it is necessary to better

  2. THE INDIVIDUAL SOVEREIGNTY: CONCEPTUALIZATION AND MANIFESTATION

    Directory of Open Access Journals (Sweden)

    Nikola Lj. Ilievski

    2015-09-01

    Full Text Available This paper is qualitative and theoretical research of the concept of sovereignty and the libertarian theory, particularly the concept of individual liberty. It represents a concept developing study, with a specific accent laid on the individual liberty, and the theoretically established concept of sovereignty. The research focus could be identified with the conceptualization and manifestation of the individual sovereignty, as a theoretical phenomenon that is not fully conceptualized and strictly defined. In the scope of this paper, content analysis method and comparative method are used. The analysis, comparison and synthesis refer to the theories of sovereignty and the theory of libertarianism, resulting in developing the concept of individual sovereignty and its socio-political manifestation.

  3. Violent and criminal manifestations in dementia patients.

    Science.gov (United States)

    Cipriani, Gabriele; Lucetti, Claudio; Danti, Sabrina; Carlesi, Cecilia; Nuti, Angelo

    2016-05-01

    Although the older adults have been studied as victims of violence, geriatric patients can display violent behavior. The purpose of the present review was to explore the phenomenon of criminal violations and violent acts in people with dementia. The authors used PubMed to search the MEDLINE database and other sources for original research and review articles on criminal and violent manifestation in demented patients combining the terms "criminal manifestation," "violence, aggressive behavior," "homicide," "suicide" and "homicide-suicide" together with "dementia". Possible biomarkers of violence are considered. The present review highlights the risk factors for violence in patients suffering from dementia, and reviews the literature about criminal violations and homicidal/suicidal behavior in this patient group. Geriatr Gerontol Int 2016; 16: 541-549. PMID:26460091

  4. [Pulmonary manifestations of connective tissue diseases].

    Science.gov (United States)

    Rehbock, B

    2015-03-01

    Systemic autoimmune diseases are responsible for about 25% of all deaths due to interstitial lung disease; therefore, an early identification of patients with pulmonary manifestation changes the management. Detection, differential diagnostic classification and staging of the pneumological pattern of findings are largely based on high-resolution computed tomography (HR-CT). The main differential diagnostic challenges are interstitial manifestations which present with radiological-histopathological phenotypes of interstitial pneumonia. The most common form of interstitial pulmonary reaction form of connective tissue diseases is the nonspecific interstitial pneumonia (NSIP) pattern. In rheumatoid arthritis, a usual interstitial pneumonia (UIP) pattern is dominant. Uncharacteristic reactions of airways and pleura can be the leading symptom or present as accompanying findings. A serious complication is pulmonary hypertension. Drug-induced lung lesions can present with similar HR-CT morphology as connective tissue diseases and can only be differentiated in the temporal and clinical context. PMID:25693496

  5. Maxillary sinus manifestations of methamphetamine abuse.

    Science.gov (United States)

    Faucett, Erynne A; Marsh, Katherine M; Farshad, Kayven; Erman, Audrey B; Chiu, Alexander G

    2015-01-01

    Methamphetamines are the second most commonly used illicit drug worldwide and cost the United States health-care system ∼$23.4 billion annually. Use of this drug affects multiple organ systems and causes a variety of clinical manifestations. Although there are commonly known sequelae of methamphetamine abuse such as "meth mouth," there is limited evidence regarding maxillary sinus manifestations. The following cases highlight the initial evaluation and management of two methamphetamine abusers with loculated purulent collections within the maxillary sinus as a result of methamphetamine abuse. Our aim was to delineate the otolaryngologic symptoms associated with the patients' methamphetamine abuse. Computed tomography and magnetic resonance imaging studies revealed loculated purulent collections within the maxillary sinus of probable odontogenic origin in both patients. Methamphetamine abuse leading to rampant caries and poor oral hygiene may predispose individuals for craniofacial infections and fluid collections. These cases illustrate the development of maxillary sinusitis and maxilla mucoceles that have been associated with methamphetamine use. PMID:25675268

  6. Neurological manifestations of Ehlers-Danlos syndrome

    Directory of Open Access Journals (Sweden)

    Mathew T

    2005-01-01

    Full Text Available Ehlers-Danlos Syndrome (EDS is more identified for its cutaneous features but its neurological manifestations have not received the focused attention. Four patients of Ehlers-Danlos Syndrome (EDS with neurological manifestations were evaluated for phenotypic data. These four men were from three families and two had consanguineous parentage. The mean age at onset and presentation of neurological symptoms were 10.5 years and 19 years respectively. Patient 1 presented with bilateral optic atrophy, sensorineural deafness, cerebellar ataxia and neuropathy. Patient 2 had marfanoid habitus, chorea and cerebellar ataxia. Patient 3 had action and percussion myotonia, wasting and weakness of sternocleidomastoid and distal limb muscles. Patient 4 had action myotonia, mirror movements of both hands and neuropathy. MRI of brain showed right parietal polymicrogyria. Neuroaxis involvement at multiple levels in EDS may have prognostic significance.

  7. Cardiac manifestations of idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Agrawal, Abhinav; Verma, Isha; Shah, Varun; Agarwal, Abhishek; Sikachi, Rutuja R

    2016-05-01

    Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, parenchymal disease of the lung with an estimated prevalence of 14-43 per 100,000. Patient usually presents with coughing and exertional dyspnea, which can lead to acute respiratory failure. IPF has been associated with various co-morbidities such as lung cancer, emphysema, obstructive sleep apnea (OSA), GERD and multiple cardiovascular consequences. The cardiovascular manifestations of IPF include pulmonary hypertension, heart failure, coronary artery disease, cardiac arrhythmias & cardiac manifestations of drugs used to treat IPF. This review will outline evidence of the association between IPF and cardiovascular conditions and attempt to provide insights into the underlying pathophysiology. We also discuss the impact of these cardiovascular diseases on patients with IPF including increased morbidity and mortality. PMID:27195188

  8. Pattern of cutaneous manifestations in diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Goyal Abhishek

    2010-01-01

    Full Text Available Background: Diabetes mellitus affects individuals of all ages and socioeconomic status. Skin is affected by the acute metabolic derangements as well as by chronic degenerative complications of diabetes. Aims: To evaluate the prevalence of skin manifestations in patients with diabetes mellitus. To analyze the prevalence and pattern of skin disorders among diabetic patients from this region of Western Himalayas. Materials and Methods: One hundred consecutive patients with the diagnosis of diabetes mellitus and having skin lesions, either attending the diabetic clinic or admitted in medical wards were included in this study. Results: The common skin disorders were: x0 erosis (44%, diabetic dermopathy (36%, skin tags (32%, cutaneous infections (31%, and seborrheic keratosis (30%. Conclusion: Skin is involved in diabetes quite often and the manifestations are numerous. High prevalence of xerosis in our diabetic population is perhaps due to cold and dry climatic conditions in the region for most of the time in the year.

  9. Antiphospholipid antibody: laboratory, pathogenesis and clinical manifestations

    Directory of Open Access Journals (Sweden)

    T. Ziglioli

    2011-06-01

    Full Text Available Antiphospholipid antibodies (aPL represent a heterogeneous group of antibodies that recognize various antigenic targets including beta2 glycoprotein I (β2GPI, prothrombin (PT, activated protein C, tissue plasminogen activator, plasmin and annexin A2. The most commonly used tests to detect aPL are: lupus anticoagulant (LAC, a functional coagulation assay, anticardiolipin antibody (aCL and anti-β2GPI antibody (anti-β2GPI, which are enzyme-linked immunoassay (ELISA. Clinically aPL are associated with thrombosis and/or with pregnancy morbidity. Apparently aPL alone are unable to induce thrombotic manifestations, but they increase the risk of vascular events that can occur in the presence of another thrombophilic condition; on the other hand obstetrical manifestations were shown to be associated not only to thrombosis but mainly to a direct antibody effect on the trophoblast.

  10. Pulmonary Paraganglioma Manifesting as an Endobronchial Mass

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Nam; Lee, Ki Nam; Roh, Mee Sook; Choi, Pil Jo; Yang, Doo Kyung [College of Medicine, Dong-A University, Pusan (Korea, Republic of)

    2008-02-15

    The thoracic manifestations of paragangliomas include well-enhancing mediastinal masses, metastatic parenchymal nodules, lymphadenopathy from malignant paragangliomas, and pulmonary edema as a complication of epinephrine-producing paragangliomas. The much less common manifestations include a primary mass in the lung, heart, esophagus and/or trachea. Primary pulmonary paraganglioma was first reported by Heppleston in 1958, and only 19 cases have been reported since then in the English literature. Three of these cases were malignancies with lymph nodes metastases. In the remaining cases, the lesions behaved in a benign manner. The patients are usually female and in their middle age. Most patients are free of symptoms and hypertension, and the tumors are often discovered incidentally on routine chest radiographs.

  11. Behavioural induced severe hypernatremia without neurological manifestations

    Directory of Open Access Journals (Sweden)

    Hassan Hossam

    2010-01-01

    Full Text Available Hypernatremia is a relatively common entity and is more prevalent among the elderly and critically ill. A number of medical conditions are commonly associated with hypernatremia, and these differ substantially among children and adults. Severe hypernatremia is usually associated with central nervous system manifestations and carries a high mortality rate. We report a case of a female patient who presented to the emergency department of the King Khalid University Hospital, Riyadh, Saudi Arabia with severe hypernatremia and without any associated co-morbid conditions or neurological manifestations. We did not find any etiological background despite extensive eva-luation other than under hydration due to decreased fluid intake, which was secondary to beha-vioural causes.

  12. Acute dacryocystitis: another clinical manifestation of sporotrichosis

    Directory of Open Access Journals (Sweden)

    Dayvison Francis Saraiva Freitas

    2014-04-01

    Full Text Available Sporotrichosis associated with exposure to domestic cats is hyperendemic in Rio de Janeiro, Brazil. A review of the clinical records at our institute revealed four patients with clinical signs of dacryocystitis and a positive conjunctival culture for Sporothrix who were diagnosed with Sporothrix dacryocystitis. Three patients were children (< 13 years of age and one patient was an adult. Two patients reported contact with a cat that had sporotrichosis. Dacryocystitis was associated with nodular, ulcerated lesions on the face of one patient and with granulomatous conjunctivitis in two patients; however, this condition manifested as an isolated disease in another patient. All of the patients were cured of the fungal infections, but three patients had chronic dacryocystitis and one patient developed a cutaneous fistula. Sporotrichosis is usually a benign disease, but may cause severe complications when the eye and the adnexa are affected. Physicians, especially ophthalmologists in endemic areas, should be aware of the ophthalmological manifestations and complications of sporotrichosis.

  13. Oral Manifestation in Mentally Challenged Children

    OpenAIRE

    Rahul, V. K.; Mathew, Cinil; Jose, Sunil; Thomas, George; Noushad, M C; Feroz, T P Mohammed

    2015-01-01

    Background: In general, mentally challenged children have higher rates poor oral hygiene, gingivitis and periodontitis than the general population. An investigation was undertaken to assess the oral manifestations of mentally challenged children in Chennai, India. Materials and Methods: The study group consisted of 150 children (70 Down syndrome patients and 80 cerebral palsy patients). Of which, 93 patients were males and 57 were females. Results: Speech difficulty hindered the communication...

  14. Arthritic manifestations of inflammatory bowel disease.

    OpenAIRE

    Suh, C. H.; Lee, C H; Lee, J.; Song, C. H.; Lee, C.W.; Kim, W. H.; S.K. Lee

    1998-01-01

    Inflammatory bowel disease (IBD) is commonly associated with arthritic manifestations. They are divided into three clinical categories; peripheral arthritis, spondylitis, and sacroiliitis. To evaluate the incidence of arthritis associated with IBD in Korea, we retrospectively reviewed one hundred and twenty-nine patients with IBD, 77 with ulcerative colitis (UC) and 52 with Crohn's disease (CD). Arthritis occurred in twenty-two patients (17.1%); 15 with UC(19.6%), 7 with CD (13.5%). Patients ...

  15. Cardiac manifestations of idiopathic pulmonary fibrosis

    OpenAIRE

    Agrawal, Abhinav; Verma, Isha; Shah, Varun; Agarwal, Abhishek; Sikachi, Rutuja R

    2016-01-01

    Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, parenchymal disease of the lung with an estimated prevalence of 14–43 per 100,000. Patient usually presents with coughing and exertional dyspnea, which can lead to acute respiratory failure. IPF has been associated with various co-morbidities such as lung cancer, emphysema, obstructive sleep apnea (OSA), GERD and multiple cardiovascular consequences. The cardiovascular manifestations of IPF include pulmonary hypertension, heart fa...

  16. Tardive Dystonia: Clinical Spectrum and Novel Manifestations

    Directory of Open Access Journals (Sweden)

    R. Jeffrey Davis

    1988-01-01

    Full Text Available Tardive dystonia was identified in 25 patients: involvement of the face and neck was most common; truncal and limb dystonia were also observed. There were 3 cases of laryngospasm and 2 of spasmodic dysphonia. The latter has not been previously reported as a manifestation of tardive dystonia. In all cases, movements typical of classic tardive dyskinesia could be demonstrated. This group illustrates the variety of dystonic disorders that may occur in conjunction with tardive dyskinesia.

  17. Palmse viinaköögi manifest

    Index Scriptorium Estoniae

    1996-01-01

    Manifest. Tõlkijate seminari puhul 17. mail 1996 Palmse viinaköögis Juta Bedia, Eric Dickens, Gyözö Fehérvári, Guntars Godinsh, Maima Grinberga, Irja Grönholm, Leif Hannibal, Cornelius Hasselblatt, Pirkko Huurto, Ivo Iliste, Nora Javorskaja, Gisbert Jänicke, Kaisu Lahikainen, Enel Melberg, Vera Ruber, Arnold Tamm, Leili Tamm, Jonatan Tomesh, Lilia Velic'kova, Marianne Vogel. Inglise k.: Estonian Literary Magazine, autumn 1996, nr. 3

  18. A rare manifestation of tuberculosis: Scrofuloderma

    Directory of Open Access Journals (Sweden)

    Savaş Öztürk

    2011-03-01

    Full Text Available Scrofuloderma is a cutaneous manifestation of tuberculosis that results from direct extension of an underlying tuberculous focus, such as lymph node to the overlying skin. In this article, 16-year-old male patient, live in a child detention home, with a purulent, ulcerated lesion in his neck, diagnosed as Scrofuloderma was presented. The case presented in order to stress that Scrofuloderma, a rare form of tuberculosis, should be kept in mind in the differential diagnosis of chronic skin lesions.

  19. Neurological manifestations of dengue viral infection

    OpenAIRE

    Carod-Artal FJ

    2014-01-01

    Francisco Javier Carod-Artal1,21Neurology Department, Raigmore hospital, Inverness, UK; 2Universitat Internacional de Catalunya (UIC), Barcelona, Spain Abstract: Dengue is the most common mosquito-borne viral infection worldwide. There is increased evidence for dengue virus neurotropism, and neurological manifestations could make part of the clinical picture of dengue virus infection in at least 0.5%–7.4% of symptomatic cases. Neurological complications have been classified into de...

  20. Musculoskeletal manifestations in hyperlipidaemia: a controlled study.

    OpenAIRE

    Klemp, P.; Halland, A M; Majoos, F L; Steyn, K

    1993-01-01

    Eighty eight patients with hyperlipidaemia (81 white patients from South Africa and seven patients of mixed race from the West Cape area) were studied. Forty eight had adult familial hypercholesterolaemia, 16 had juvenile familial hypercholesterolaemia, and 24 had mixed hyperlipidaemia (increased cholesterol and triglycerides). They were interviewed and examined and their musculoskeletal manifestations compared with 88 controls with normal lipid profiles, and matched for age, sex, and race fo...

  1. Peripheral Nervous System Manifestations of Infectious Diseases

    OpenAIRE

    Brizzi, Kate T.; Lyons, Jennifer L.

    2014-01-01

    Infectious causes of peripheral nervous system (PNS) disease are underrecognized but potentially treatable. Heightened awareness educed by advanced understanding of the presentations and management of these infections can aid diagnosis and facilitate treatment. In this review, we discuss the clinical manifestations, diagnosis, and treatment of common bacterial, viral, and parasitic infections that affect the PNS. We additionally detail PNS side effects of some frequently used antimicrobial ag...

  2. Patent foramen ovale: clinical manifestations and treatment.

    OpenAIRE

    Kedia, G; Tobis, J; Lee, MS

    2008-01-01

    A persistent patent foramen ovale produces an intermittent intra-atrial right-to-left shunt and occurs in approximately 25% of the general population. Although the vast majority of people with patent foramen ovale are asymptomatic, a patent foramen ovale is believed to act as a pathway for chemicals or thrombus that can result in a variety of clinical manifestations, including stroke, migraine headache, decompression sickness, high-altitude pulmonary edema, and platypnea-orthodeoxia syndrome....

  3. THE INDIVIDUAL SOVEREIGNTY: CONCEPTUALIZATION AND MANIFESTATION

    OpenAIRE

    Nikola Lj. Ilievski

    2015-01-01

    This paper is qualitative and theoretical research of the concept of sovereignty and the libertarian theory, particularly the concept of individual liberty. It represents a concept developing study, with a specific accent laid on the individual liberty, and the theoretically established concept of sovereignty. The research focus could be identified with the conceptualization and manifestation of the individual sovereignty, as a theoretical phenomenon that is not fully conceptualized and stric...

  4. The individual sovereignty: conceptuatization and manifestation

    OpenAIRE

    Ilievski, Nikola Lj.

    2015-01-01

    "This paper is qualitative and theoretical research of the concept of sovereignty and the libertarian theory, particularly the concept of individual liberty. It represents a concept developing study, with a specific accent laid on the individual liberty, and the theoretically established concept of sovereignty. The research focus could be identified with the conceptualization and manifestation of the individual sovereignty, as a theoretical phenomenon that is not fully conceptualized and stri...

  5. Modified gravity. Problems and observational manifestations

    CERN Document Server

    Arbuzova, E V

    2012-01-01

    Some models of modified gravity and their observational manifestations are considered. It is shown, that gravitating systems with mass density rising with time evolve to a singular state with infinite curvature scalar. The universe evolution during the radiation dominated epoch is studied in $R^2$-extended gravity theory. Particle production rate by the oscillating curvature is calculated. Possible implications of the model for cosmological creation of non-thermal dark matter are discussed.

  6. Cutaneous Manifestations of Systemic Lupus Erythematosus

    OpenAIRE

    Luís Uva; Diana Miguel; Catarina Pinheiro; João Pedro Freitas; Manuel Marques Gomes; Paulo Filipe

    2012-01-01

    Systemic lupus erythematosus (SLE) is a multiorgan autoimmune disease of unknown etiology with many clinical manifestations. The skin is one of the target organs most variably affected by the disease. The American College of Rheumatology (ACR) established 11 criteria as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individuals and do not do well in that capacity. Cutaneous lesions account for four of these...

  7. Rheumatic manifestations of inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Tatiana Sofía Rodríguez-Reyna, Cynthia Martínez-Reyes, Jesús Kazúo Yamamoto-Furusho

    2009-11-01

    Full Text Available This article reviews the literature concerning rheumatic manifestations of inflammatory bowel disease (IBD, including common immune-mediated pathways, frequency, clinical course and therapy. Musculoskeletal complications are frequent and well-recognized manifestations in IBD, and affect up to 33% of patients with IBD. The strong link between the bowel and the osteo-articular system is suggested by many clinical and experimental observations, notably in HLA-B27 transgenic rats. The autoimmune pathogenic mechanisms shared by IBD and spondyloarthropathies include genetic susceptibility to abnormal antigen presentation, aberrant recognition of self, the presence of autoantibodies against specific antigens shared by the colon and other extra-colonic tissues, and increased intestinal permeability. The response against microorganisms may have an important role through molecular mimicry and other mechanisms. Rheumatic manifestations of IBD have been divided into peripheral arthritis, and axial involvement, including sacroiliitis, with or without spondylitis, similar to idiopathic ankylosing spondylitis. Other periarticular features can occur, including enthesopathy, tendonitis, clubbing, periostitis, and granulomatous lesions of joints and bones. Osteoporosis and osteomalacia secondary to IBD and iatrogenic complications can also occur. The management of the rheumatic manifestations of IBD consists of physical therapy in combination with local injection of corticosteroids and nonsteroidal anti-inflammatory drugs; caution is in order however, because of their possible harmful effects on intestinal integrity, permeability, and even on gut inflammation. Sulfasalazine, methotrexate, azathioprine, cyclosporine and leflunomide should be used for selected indications. In some cases, tumor necrosis factor-α blocking agents should be considered as first-line therapy.

  8. Imaging of Spinal Manifestations of Hematological Disorders.

    Science.gov (United States)

    Pawha, Puneet S; Chokshi, Falgun H

    2016-08-01

    Imaging manifestations of hematological diseases and their potential complications are broad, and there may be significant overlap in features of various disease processes. Knowledge of appropriate choice of imaging test, pertinent imaging patterns, and pathophysiology of disease can help the reader increase specificity in the diagnosis and treatment of the patient. Most importantly, we encourage readers of this review to engage their radiologists during the diagnostic, treatment, and management phases of care delivery. PMID:27444004

  9. Coronary Artery Manifestations of Fibromuscular Dysplasia

    OpenAIRE

    Michelis, Katherine C.; Olin, Jeffrey W.; Kadian-Dodov, Daniella; D’Escamard, Valentina; Kovacic, Jason C.

    2014-01-01

    Fibromuscular dysplasia (FMD) involving the coronary arteries is an uncommon but important condition that can present as acute coronary syndrome, left ventricular dysfunction, or potentially sudden cardiac death. Although the classic angiographic “string of beads” that may be observed in renal artery FMD does not occur in coronary arteries, potential manifestations include spontaneous coronary artery dissection, distal tapering or long, smooth narrowing that may represent dissection, intramur...

  10. Alagille syndrome with prominent skin manifestations

    OpenAIRE

    Das Jayanta; Gangopadhyay Asok; Sengupta Sujata

    2005-01-01

    Alagille syndrome, a rare genetic disorder with autosomal dominant transmission, manifests 5 major features: paucity of interlobular bile ducts, characteristic facies, posterior embryotoxon, vertebral defects and peripheral pulmonic stenosis. We report a 6-year-old male child who presented with a history of progressive jaundice since infancy, generalized pruritus and widespread cutaneous xanthomata. He was also found to have obstructive jaundice, pulmonary stenosis with ventricular septal def...

  11. Behavioural induced severe hypernatremia without neurological manifestations

    OpenAIRE

    Hassan Hossam; Al Aseri Zohair; Suriya Owais

    2010-01-01

    Hypernatremia is a relatively common entity and is more prevalent among the elderly and critically ill. A number of medical conditions are commonly associated with hypernatremia, and these differ substantially among children and adults. Severe hypernatremia is usually associated with central nervous system manifestations and carries a high mortality rate. We report a case of a female patient who presented to the emergency department of the King Khalid University Hospital, Riyadh, Saudi Arabia...

  12. The radiological manifestations of sickle cell disease

    Energy Technology Data Exchange (ETDEWEB)

    Madani, G. [Department of Radiology, Royal Free Hospital NHS Trust, London (United Kingdom)]. E-mail: gittamadani@yahoo.com; Papadopoulou, A.M. [Department of Radiology, Royal Free Hospital NHS Trust, London (United Kingdom); Holloway, B. [Department of Radiology, Royal Free Hospital NHS Trust, London (United Kingdom); Robins, A. [Department of Paediatrics, Whittington Hospital NHS Trust, London (United Kingdom); Davis, J. [Department of Radiology, Whittington Hospital NHS Trust, London (United Kingdom); Murray, D. [Department of Radiology, Whittington Hospital NHS Trust, London (United Kingdom)

    2007-06-15

    Sickle cell disease (SCD) is an inherited abnormality of the ss-globin chain, which causes a spectrum of haemolytic anaemias. Clinical manifestations in SCD include anaemia, jaundice, recurrent vaso-occlusive crises, and infections (particularly by encapsulated bacteria) due to functional asplenia and cerebrovascular accidents. Radiological investigations play a critical role both in the diagnosis and in the primary prevention of the complications of SCD.

  13. A High Load of Non-neutral Amino-Acid Polymorphisms Explains High Protein Diversity Despite Moderate Effective Population Size in a Marine Bivalve With Sweepstakes Reproduction

    OpenAIRE

    Harrang, Estelle; Lapègue, Sylvie; Morga, Benjamin; Bierne, Nicolas

    2013-01-01

    Marine bivalves show among the greatest allozyme diversity ever reported in Eukaryotes, putting them historically at the heart of the neutralist-selectionist controversy on the maintenance of genetic variation. Although it is now acknowledged that this high diversity is most probably a simple consequence of a large population size, convincing support for this explanation would require a rigorous assessment of the silent nucleotide diversity in natural populations of marine bivalves, which has...

  14. A Survey of Mercury Concentrations in Soft Tissue of Bivalves Callista umbonella, Saccostrea cucullata and Sediment in the Coastline of Bandar Abbas

    OpenAIRE

    Zahra Bagheri; Alireza Riyahi Bakhtiari

    2014-01-01

    Background and Objectives: The present study was designed to determine total mercury concentrations in sediment and the soft tissues of two bivalve species, Saccostrea cucullata and Callista umbonella, in coastline of Bandar Abbas in 2011. Materials and Methods: Generally, 67 bivalves and 10 sediment samples were collected from two stations (terminal of Bandar Abbas and tourism park of Soro). We measured total mercury concentrations in each sample using Mercury Analyzer (Leco AMA 254). ...

  15. Abdominal manifestations of cystic fibrosis in children

    International Nuclear Information System (INIS)

    Pulmonary complications remain the main cause of mortality in cystic fibrosis, but the presenting symptoms in children are often related to gastrointestinal or pancreaticobiliary disease. Furthermore, abdominal manifestations are now seen throughout childhood, from infancy to adolescence. The child might present in the neonatal period with meconium ileus or its attendant complications. The older child might present with distal intestinal obstruction syndrome or colonic stricture secondary to high doses of pancreatic enzyme replacement. Less-common gastrointestinal manifestations include intussusception, duodenitis and fecal impaction of the appendix. Most children also show evidence of exocrine pancreatic deficiency. Radiologically, the combination of fat deposition and pancreatic fibrosis leads to varying CT and MR appearances. A higher than normal incidence of pancreatic cysts and calcification is also seen. Decreased transport of water and chloride also increases the viscosity of bile, with subsequent obstruction of the biliary ductules. If extensive, this can progress to obstructive cirrhosis, portal hypertension and esophageal varices. Diffuse fatty infiltration, hypersplenism and gallstones are also commonly seen in these patients. We present a pictorial review of the radiological appearance of these abdominal manifestations. The conditions are dealt with individually, together with typical appearances in various imaging modalities. (orig.)

  16. Abdominal manifestations of cystic fibrosis in children

    Energy Technology Data Exchange (ETDEWEB)

    Chaudry, Gulraiz; Navarro, Oscar M.; Levine, Daniel S.; Oudjhane, Kamaldine [University of Toronto, Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, ON (Canada)

    2006-03-15

    Pulmonary complications remain the main cause of mortality in cystic fibrosis, but the presenting symptoms in children are often related to gastrointestinal or pancreaticobiliary disease. Furthermore, abdominal manifestations are now seen throughout childhood, from infancy to adolescence. The child might present in the neonatal period with meconium ileus or its attendant complications. The older child might present with distal intestinal obstruction syndrome or colonic stricture secondary to high doses of pancreatic enzyme replacement. Less-common gastrointestinal manifestations include intussusception, duodenitis and fecal impaction of the appendix. Most children also show evidence of exocrine pancreatic deficiency. Radiologically, the combination of fat deposition and pancreatic fibrosis leads to varying CT and MR appearances. A higher than normal incidence of pancreatic cysts and calcification is also seen. Decreased transport of water and chloride also increases the viscosity of bile, with subsequent obstruction of the biliary ductules. If extensive, this can progress to obstructive cirrhosis, portal hypertension and esophageal varices. Diffuse fatty infiltration, hypersplenism and gallstones are also commonly seen in these patients. We present a pictorial review of the radiological appearance of these abdominal manifestations. The conditions are dealt with individually, together with typical appearances in various imaging modalities. (orig.)

  17. Influence of incubation conditions on the anoxic survival of marine bivalves. Static and semi-static incubations

    OpenAIRE

    Zwaan, A.; Cattani, O; Vitali, G.; Cortesi, P

    2001-01-01

    In a comparative study of 4 bivalve species we show that the apparent widely different tolerances in survival time observed in a closed system filled with N-2-gassed seawater is mainly due to the experimental conditions. Both a high dose of cadmium and the antibiotic chloramphenicol increase survival time 2- to 4-fold. Without precautions for bacterial growth, the survival time of the most tolerant species, Scapharca inaequivalvis, is about 4 times longer than that of the most sensitive speci...

  18. The influence of temperature and seawater carbonate saturation state on 13C–18O bond ordering in bivalve mollusks

    Directory of Open Access Journals (Sweden)

    R. A. Eagle

    2013-07-01

    Full Text Available The shells of marine mollusks are widely used archives of past climate and ocean chemistry. Whilst the measurement of mollusk δ18O to develop records of past climate change is a commonly used approach, it has proven challenging to develop reliable independent paleothermometers that can be used to deconvolve the contributions of temperature and fluid composition on molluscan oxygen isotope compositions. Here we investigate the temperature dependence of 13C–18O bond abundance, denoted by the measured parameter Δ47, in shell carbonates of bivalve mollusks and assess its potential to be a useful paleothermometer. We report measurements on cultured specimens spanning a range in water temperatures of 5 to 25 °C, and field collected specimens spanning a range of −1 to 29 °C. In addition we investigate the potential influence of carbonate saturation state on bivalve stable isotope compositions by making measurements on both calcitic and aragonitic specimens that have been cultured in seawater that is either supersaturated or undersaturated with respect to aragonite. We find a robust relationship between Δ47 and growth temperature. We also find that the slope of a linear regression through all the Δ47 data for bivalves plotted against seawater temperature is significantly shallower than previously published inorganic and biogenic carbonate calibration studies produced in our laboratory and go on to discuss the possible sources of this difference. We find that changing seawater saturation state does not have significant effect on the Δ47 of bivalve shell carbonate in two taxa that we examined, and we do not observe significant differences between Δ47-temperature relationships between calcitic and aragonitic taxa.

  19. Prevalence and serotyping of Listeria monocytogenes in Portuguese live bivalve molluscs sampled in various steps along the sanitary control process

    OpenAIRE

    Pinto, Ana Luísa; Teixeira, Paula; Castilho, Fernanda; Felício, Maria Teresa; Pombal, Filomena

    2006-01-01

    The prevalence and contamination levels of Listeria monocytogenes were investigated in live bivalve molluscs for human consumption, collected in various steps of the commercial and sanitary circuits in the North of Portugal. Samples of di¡erent species were collected per lot before and after depuration treatment in two depuration units and further, when placed in retail markets. Listeria monocytogenes was isolated from 4% of the samples although with very low contam...

  20. Rapid evolution of sessility in an endemic species flock of the freshwater bivalve Corbicula from ancient lakes on Sulawesi, Indonesia

    OpenAIRE

    von Rintelen, Thomas; Glaubrecht, Matthias

    2005-01-01

    The fauna of ancient lakes frequently contains taxa with highly derived morphologies that resulted from in situ radiation of lacustrine lineages with high antiquity. We employed a molecular mtDNA phylogeny to investigate this claim for corbiculid freshwater bivalves in two ancient lake systems on the Indonesian island Sulawesi. Among the otherwise mobile corbiculid species flock, only one taxon, Posostrea anomioides, in the ancient Lake Poso exhibits a unique habit, i.e. cementing one valve t...

  1. Stable isotopes in bivalves as indicators of nutrient source in coastal waters in the Bocas del Toro Archipelago, Panama.

    Science.gov (United States)

    Graniero, Lauren E; Grossman, Ethan L; O'Dea, Aaron

    2016-01-01

    To examine N-isotope ratios ((15)N/(14)N) in tissues and shell organic matrix of bivalves as a proxy for natural and anthropogenic nutrient fluxes in coastal environments, Pinctada imbricata, Isognomon alatus, and Brachidontes exustusbivalves were live-collected and analyzed from eight sites in Bocas del Toro, Panama. Sites represent a variety of coastal environments, including more urbanized, uninhabited, riverine, and oceanic sites. Growth under differing environmental conditions is confirmed by δ (18)O values, with open ocean Escudo de Veraguas shells yielding the highest average δ (18)O (-1.0‰) value and freshwater endmember Rio Guarumo the lowest (-1.7‰). At all sites there is no single dominant source of organic matter contributing to bivalve δ (15)N and δ (13)C values. Bivalve δ (15)N and δ (13)C values likely represent a mixture of mangrove and seagrass N and C, although terrestrial sources cannot be ruled out. Despite hydrographic differences between end-members, we see minimal δ (15)N and δ (13)C difference between bivalves from the river-influenced Rio Guarumo site and those from the oceanic Escudo de Veraguas site, with no evidence for N from open-ocean phytoplankton in the latter. Populated sites yield relative (15)N enrichments suggestive of anthropogenic nutrient input, but low δ (15)N values overall make this interpretation equivocal. Lastly, δ (15)N values of tissue and shell organic matrix correlate significantly for pterioideans P. imbricata and I. alatus. Thus for these species, N isotope studies of historical and fossil shells should provide records of ecology of past environments. PMID:27547578

  2. Suspended material availability and filtration-biodeposition processes performed by a native and invasive bivalve species in streams

    Science.gov (United States)

    Atkinson, C.L.; First, M.R.; Covich, A.P.; Opsahl, S.P.; Golladay, S.W.

    2011-01-01

    Unionid mussels are among the most threatened group of freshwater organisms globally. They are known for their ability to filter food particles from flowing and standing waters. However, invasive bivalve species, such as the Asian clam (Corbicula fluminea) in North America, have the potential to overlap in feeding and potentially out-compete the native species. Yet, the feeding preferences of unionid mussels and C. fluminea are incompletely understood. We hypothesized that Elliptio crassidens (native) and C. fluminea (invasive) would select for specific organic components present within seston. We examined changes in seston (dry mass and ash-free dry mass) resulting from bivalve feeding activity for three size classes of material that were isolated using gravimetric filtration. The treatments were also sub-sampled for flow cytometry (FC) which separated the suspended materials in the stream water into five categories: detritus, heterotrophic bacteria, picoautotrophs, nanoautotrophs, and heterotrophic nanoeukaryotes. Our results indicated that both species of bivalve showed preferences for organic and living materials. E. crassidens preferentially filtered nanoeukaryotes, whose decreases were associated with an increase in bacteria. In contrast, C. fluminea preferred smaller materials through selective filtration of picoautotrophs. In addition, both species increased the concentration of large materials toward the end of the experiment because of the suspension of their pseudofeces biodeposits. To our knowledge, this study is the first to examine grazing by bivalve species on natural stream particulate matter using FC. Our results suggest that native and non-native mussels have different functional roles, which has important implications for organic matter processing and food webs in streams. ?? 2011 Springer Science+Business Media B.V.

  3. Abundance not linked to survival across the end-Cretaceous mass extinction: Patterns in North American bivalves

    OpenAIRE

    Lockwood, Rowan

    2003-01-01

    Ecological studies suggest that rare taxa are more likely to go extinct than abundant ones, but the influence of abundance on survivorship in the fossil record has received little attention. An analysis of Late Maastrichtian bivalve subgenera from the North American Coastal Plain found no evidence that survivorship is tied to abundance across the end-Cretaceous mass extinction (65 million years ago), regardless of abundance metric or spatial scale examined. The fact that abundance does not pr...

  4. Stable isotopes in bivalves as indicators of nutrient source in coastal waters in the Bocas del Toro Archipelago, Panama

    Science.gov (United States)

    Grossman, Ethan L.; O’Dea, Aaron

    2016-01-01

    To examine N-isotope ratios (15N/14N) in tissues and shell organic matrix of bivalves as a proxy for natural and anthropogenic nutrient fluxes in coastal environments, Pinctada imbricata, Isognomon alatus, and Brachidontes exustusbivalves were live-collected and analyzed from eight sites in Bocas del Toro, Panama. Sites represent a variety of coastal environments, including more urbanized, uninhabited, riverine, and oceanic sites. Growth under differing environmental conditions is confirmed by δ18O values, with open ocean Escudo de Veraguas shells yielding the highest average δ18O (−1.0‰) value and freshwater endmember Rio Guarumo the lowest (−1.7‰). At all sites there is no single dominant source of organic matter contributing to bivalve δ15N and δ13C values. Bivalve δ15N and δ13C values likely represent a mixture of mangrove and seagrass N and C, although terrestrial sources cannot be ruled out. Despite hydrographic differences between end-members, we see minimal δ15N and δ13C difference between bivalves from the river-influenced Rio Guarumo site and those from the oceanic Escudo de Veraguas site, with no evidence for N from open-ocean phytoplankton in the latter. Populated sites yield relative 15N enrichments suggestive of anthropogenic nutrient input, but low δ15N values overall make this interpretation equivocal. Lastly, δ15N values of tissue and shell organic matrix correlate significantly for pterioideans P. imbricata and I. alatus. Thus for these species, N isotope studies of historical and fossil shells should provide records of ecology of past environments. PMID:27547578

  5. A comparative study on effects of heterotrophic microbial activity on the stability of bivalve and coral carbonate during early diagenesis.

    Science.gov (United States)

    Lange, Skadi M.; Krause, Stefan; Immenhauser, Adrian; Ritter, Ann-Christin; Gorb, Stanislav N.; Kleinteich, Thomas; Treude, Tina

    2016-04-01

    Following deposition and shallow burial, marine biogenic carbonates are exposed to an environment that is geochemically affected by a manifold of bacterial metabolic redox processes. To allow for comparison of potential microbe-mediated alteration effects on carbonates, we used aragonitic bivalve shell samples and porous aragonitic coral fragments for incubation experiments in oxic- and anoxic seawater media. The media contained marine sediment slurries or bacterial cultures to mimic the natural processes in vitro. The results for anoxic experimental media containing bivalve shell samples or coral fragments displayed considerable changes in carbonate-system parameters (pH, AT, CA, DIC) and divalent-cation ratios (Mg/Ca, Mg/Sr, Sr/Ca) over time. Furthermore, incubated bivalve shell samples were altered in morphology, elemental composition and isotopic signature. Coral-fragment bearing oxic incubations were run at two temperature regimes and divalent-cation ratios of the high-temperature bacterial medium displayed withdrawal of Ca2+ and Sr2+ from the medium, thus indicating microbe-induced secondary aragonite precipitation. Analyses of coral fragments include electron-microprobe mapping and X-ray microtomography to resolve elemental sample composition and pore-space alteration features, respectively. Up to this point our results indicate that heterotrophic bacterial activity has the potential to affect surficial or open pore space in carbonate archives by increasing rates of alteration relative to sterile environments.

  6. Anatomical study on Myoforceps aristatus, an invasive boring bivalve in S.E. Brazilian coast (Mytilidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2006-01-01

    Full Text Available The bivalve Myoforceps aristatus (Dillwyn, 1817, also known as Lithophaga aristata, have been recently collected in the coasts of Rio de Janeiro and São Paulo, Brazil; a species that bores shells of other mollusks. This occurrence has been interpreted as an invasion of this species, originally from the Caribbean. The distinguishing character of the species is the posterior extensions of the shell crossing with each other. Because specimens with this character have also been collected in the Pacific Ocean, they all have been considered a single species. However, it is possible that more than one species may be involved in such worldwide distribution. With the objective of providing full information based on Atlantic specimens, a complete anatomical description is provided, which can be used in comparative studies with specimens from other oceans. Additional distinctive features of M. aristatus are the complexity of the incurrent siphon, the kidney opening widely into the supra-branchial chamber (instead of via a nephropore, and the multi-lobed auricle.O bivalve Myoforceps aristatus (Dillwyn, 1817, também conhecido como Lithophaga aristata, tem sido recentemente coletado nas costas do Rio de Janeiro e São Paulo, Brasil; uma espécie que perfura conchas de outros moluscos. Esta ocorrência está sendo interpretada como uma invasão de uma espécie originada do Caribe. O caráter distintivo da espécie é a região posterior da concha, com extensões que se cruzam. Como espécimes com esta característica também têm sido coletados no oceano Pacífico, eles tem sido considerados como pertencentes à mesma espécie. Entretanto, é possível que mais de uma espécie possam estar envolvidas nesta suposta distribuição mundial. Com o objetivo de fornecer informação completa baseada em material do Atlântico, uma descrição anatômica completa é dada, a qual pode ser usada em estudos comparativos com espécimes de outros oceanos. As caracter

  7. Complications of atticoantral cholesteatoma: MR manifestations

    International Nuclear Information System (INIS)

    Cholesteatoma of the temporal bone usually occurs in the attic (epitympanic cavity) and extends easily into the mastoid antrum through the aditus as antrum. Since atticoantral cholesteatoma can lead to clinically serious complications, successful patient management requires an accurate knowledge of the extent of the condition. All complications of cholesteatoma are in fact related to bony erosion and may be classified as labyrinthitis, extracranial complication, meningitis, dural sinus obstruction, or parenchymal inflammation. This paper describes the diverse MR manifestations of the complications arising from atticoantral cholesteatoma. (author)

  8. Complications of atticoantral cholesteatoma: MR manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Hyun; Lee, Ho Kyu; Lim, Soo Mi; Shin, Ji Hoon; Choi, Choong Gon; Suh, Dae Chul; Lee, Kwang Sun [Asan Medical Center, College of Medicine, University of Ulsan, Ulsan (Korea, Republic of)

    2000-02-01

    Cholesteatoma of the temporal bone usually occurs in the attic (epitympanic cavity) and extends easily into the mastoid antrum through the aditus as antrum. Since atticoantral cholesteatoma can lead to clinically serious complications, successful patient management requires an accurate knowledge of the extent of the condition. All complications of cholesteatoma are in fact related to bony erosion and may be classified as labyrinthitis, extracranial complication, meningitis, dural sinus obstruction, or parenchymal inflammation. This paper describes the diverse MR manifestations of the complications arising from atticoantral cholesteatoma. (author)

  9. Nephrogenic systemic fibrosis: late skin manifestations

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Marckmann, Peter; Rossen, Kristian;

    2009-01-01

    confluent dermal plaques with thickening and hardening. In contrast, 3 patients presented with wrinkled, redundant skin as seen in cutis laxa. Patients with NSF had significantly poorer scores than control patients on the Daily Life Quality Index (mean [SD], 11. 4 [7.4] vs 1.5 [2. 3]; P < .001). CONCLUSIONS......BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a serious disease that occurs in patients with severe renal disease and is believed to be caused by gadolinium-containing contrast agents. A detailed description of the late skin manifestations of NSF is important to help dermatologists and...

  10. Manifest Duality for Partially Massless Higher Spins

    CERN Document Server

    Hinterbichler, Kurt

    2016-01-01

    In four dimensions, partially massless fields of all spins and depths possess a duality invariance akin to electric-magnetic duality. We construct metric-like gauge invariant curvature tensors for partially massless fields of all integer spins and depths, and show how the partially massless equations of motion can be recovered from first order field equations and Bianchi identities for these curvatures. This formulation displays duality in its manifestly local and covariant form, in which it acts to interchange the field equations and Bianchi identities.

  11. On the history of nuclear matrix manifestation

    Institute of Scientific and Technical Information of China (English)

    ZBARSKYIB

    1998-01-01

    The nonchromatin proteinous residue of the cell nucleus was revealed in our laboratory as early as in 1948 and then identified by light and electron microscopy as residual nucleoli,intranuclear network and nuclear envelope before 1960,This structure termed afterwards as "nuclear residue","nuclear skeleton","nuclear cage","nuclear carcass"etc.,was much later(in 1974) isolated,studied and entitled as "nuclear matrix" by Berezney and Coffey,to whom the discovery of this residual structure is often wronly ascribed.The real history of nuclear matrix manifestation is reported in this paper.

  12. Research Misconduct—Definitions, Manifestations and Extent

    Directory of Open Access Journals (Sweden)

    Lutz Bornmann

    2013-10-01

    Full Text Available In recent years, the international scientific community has been rocked by a number of serious cases of research misconduct. In one of these, Woo Suk Hwang, a Korean stem cell researcher published two articles on research with ground-breaking results in Science in 2004 and 2005. Both articles were later revealed to be fakes. This paper provides an overview of what research misconduct is generally understood to be, its manifestations and the extent to which they are thought to exist.

  13. Manifestly Local Theory of Vacuum Energy Sequestering.

    Science.gov (United States)

    Kaloper, Nemanja; Padilla, Antonio; Stefanyszyn, David; Zahariade, George

    2016-02-01

    We present a manifestly local, diffeomorphism invariant, and locally Poincaré invariant formulation of vacuum energy sequestering. In this theory, quantum vacuum energy generated by matter loops is canceled by auxiliary fields. The auxiliary fields decouple from gravity almost completely. Their only residual effect is an a priori arbitrary, finite contribution to the curvature of the background geometry, which is radiatively stable. Its value is to be determined by a measurement, like the finite part of any radiatively stable UV-sensitive quantity in quantum field theory. PMID:26894700

  14. Reiki and changes in pattern manifestations.

    Science.gov (United States)

    Ring, Marcia E

    2009-07-01

    The purposes of this qualitative research study were to describe the changes in pattern manifestations that individuals experienced associated with receiving Reiki, and to present the theoretical understanding of these changes. The unitary field pattern portrait research method was utilized because it was ontologically, epistemologically, and methodologically consistent with the science of unitary human beings. Reiki was found to be associated with changes in awareness from dissonance and turbulence to harmony and well-being by helping individuals knowingly participate in actualizing their own capacities for healing. Reiki was found to be an appropriate voluntary mutual patterning nursing modality. PMID:19567731

  15. Manifestation of psoriasis in the oral cavity.

    Science.gov (United States)

    Fatahzadeh, Mahnaz

    2016-03-01

    Despite the common prevalence of cutaneous psoriasis, the existence of manifestations in the oral cavity is subject to controversy. In this article, dermatologic psoriasis is reviewed, and a patient with generalized, symptomatic oral mucosal erythema resembling atrophic candidiasis synchronous with flare of chronic skin psoriasis is described. Diagnostic work up and therapeutic response supported that these mucosal findings were the oral counterpart of cutaneous disease. Dental providers should be familiar with the signs and symptoms of oral psoriasis, institute appropriate preventive measures, and provide palliation directed at symptomatic oral changes of psoriasis. PMID:26665263

  16. 珍珠层复合堆叠材料中弹性波传播特性研究%Propagation properties of elastic waves in a stacking composite material like nacre

    Institute of Scientific and Technical Information of China (English)

    黄佳; 尹进; 张盛; 陈飙松; 张洪武

    2014-01-01

    A tension-shear chain model and a 2D finite element model of nacre,a kind of stacking composite material,were built up,and its band gap was computed based on a multi-level substructure scheme.The results showed that the nacre-like material is a kind of Bragg phononic crystal holding a relatively wide first order band gap in a lower frequency domain and several flat bands in a higher frequency domain,so this kind of material can lead to the vibration reduction in a wide frequency range;moreover,this kind of material is more efficient to realize the goal of vibration reduction at low frequencies,because it doesn't have Fano-like interference phenomena,they happen in local areas resonant phononic crystals for the mechanism of their band gaps.Furthermore,the transmission characteristics were computed to verify the results of band gap.The further study demonstrated that band gap characteristics are mainly influenced by the density of the hard mineral component (“Brick”) and the elastic modulus of the soft component (“Mortar”),the first order band gap of nacre-like material subjects to the coupling influence of the two material parameters;an appropriate match of the two material parameters can gain a larger relative band gap,the band gap is adjustable as well.The nacre-like material provided a guide for the design of new vibration reduction materials.%通过建立珍珠层复合堆叠材料的拉伸剪切链模型和二维有限元模型,利用多重多级子结构方法研究声子晶体材料带隙特性。结果表明,珍珠层材料是一种具有较低及较宽一阶带隙且多个高频平直带的Bragg型声子晶体,这意味着此材料会导致非常宽的频率衰减区出现,并且其结构与带隙产生机理均不同于局域共振型声子晶体,所以不会出现类Fano干涉现象,更利于实现低频减振的目的。传输特性计算验证了多重多级子结构带隙计算结果的正确性和有效性。进一步研究表明

  17. Comparative analysis of morphometric characteristics of bivalves Anodonta piscinalis from the reservoirs of techa cascade of Mayak Production Association

    Energy Technology Data Exchange (ETDEWEB)

    Yegoreichenkov, E.; Pryakhin, E.; Akleyev, A. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation)

    2014-07-01

    The reservoirs R-11, R-10 and R-4 of the Techa cascade (Chelyabinsk region) are used as low-active radioactive wastes storages, and are separated from open hydrographical network by a system of dams and by-pass channels. The values of specific activity of radionuclides in water and bottom sediments increases in the row: R-11, R-10, R-4, and at the same time the dose rate for zoo-benthos is increased on an order from reservoir to reservoir. Bivalves, which are obligate filter feeders and produce a significant part of water community biomass, are an important part of energy and matter transformation chain inside the hydro-biocenosis. Among this group of animals, the Anodonta piscinalis, a massive bivalve, takes the most part in biomass of Techa reservoirs cascade. Several studies show that in polluted environment the shell morphology changes are possible: the ratio of most morphometric values changes; the level of fluctuated asymmetry and shell polymorphism increases. For morphological studies of bivalves populations, 34 specimens of Anodonta were taken from R-11, 43 specimens from R-10 and 4 specimens from R-4. The specimens selection was arranged in May 2013, using hydro-biological drag. The shell shape was analyzed using TPS DIG software. Besides the measurements of maximal shell length, shell height, and the distance between shell's top and maximally distant point of front edge of the shell were measured. The ratio between the length and the height of the shell, between the length and the distance from the top to the front edge were calculated. The data analysis was arranged using R statistics. As a result of the data analysis the significant difference between shell's length to height ratios were registered between populations of R-4 and R-10 (p = 0.002). The ratio of maximal length of the shell to the distance from the top to the front edge also significantly differs between the animals of the R-4 and R-10 reservoirs (?= 0.03). Between the animals of

  18. CANDLE Syndrome: orodfacial manifestations and dental implications.

    Science.gov (United States)

    Roberts, T; Stephen, L; Scott, C; di Pasquale, T; Naser-Eldin, A; Chetty, M; Shaik, S; Lewandowski, L; Beighton, P

    2015-01-01

    A South African girl with CANDLE Syndrome is reported with emphasis on the orodental features and dental management. Clinical manifestations included short stature, wasting of the soft tissue of the arms and legs, erythematous skin eruptions and a prominent abdomen due to hepatosplenomegaly. Generalized microdontia, confirmed by tooth measurement and osteopenia of her jaws, confirmed by digitalized radiography, were previously undescribed syndromic components. Intellectual impairment posed problems during dental intervention. The carious dental lesions and poor oral hygiene were treated conservatively under local anaesthetic. Prophylactic antibiotics were administered an hour before all procedures.Due to the nature of her general condition, invasive dental procedures were minimal. Regular follow-ups were scheduled at six monthly intervals. During this period, her overall oral health status had improved markedly.The CANDLE syndrome is a rare condition with grave complications including immunosuppression and diabetes mellitus. As with many genetic disorders, the dental manifestations are often overshadowed by other more conspicuous and complex syndromic features. Recognition of both the clinical and oral changes that occur in the CANDLE syndrome facilitates accurate diagnosis and appropriate dental management of this potentially lethal condition. PMID:26711936

  19. Cutaneous and ocular manifestations of neurocutaneous syndromes.

    Science.gov (United States)

    Chernoff, Karen A; Schaffer, Julie V

    2016-01-01

    Neurocutaneous syndromes are a heterogeneous group of congenital and hereditary disorders with manifestations in the skin and the nervous system, usually together with ocular features that represent diagnostic clues and potential sources of morbidity. Dermatologists and ophthalmologists often need to work together in identifying and managing patients with these conditions; herein, we focus on classic and under-recognized neurocutaneous syndromes. We begin with autosomal dominant genodermatoses characterized by hamartomas and tumors in the skin, eyes, and central nervous system: neurofibromatosis type 1, tuberous sclerosis complex, and PTEN hamartoma-tumor syndrome. This is followed by a discussion of two mosaic disorders, Sturge-Weber syndrome and neurocutaneous melanocytosis. In addition to providing an update on clinical presentations and evaluation of patients with these conditions, we review recent insights into their pathogenesis, drawing attention to relationships among the diseases on a molecular level and implications regarding treatment. We also highlight the major features of other neurocutaneous syndromes that have ocular findings plus pigmentary, vascular, hyperkeratotic, adnexal, connective tissue, photosensitive, and inflammatory manifestations in the skin. PMID:26903185

  20. Neurological manifestations of Batch s disease

    International Nuclear Information System (INIS)

    To determine the prevalence, clinical manifestations, and laboratory features of Neuro-Behcets disease. This prospective study was carried out in the Behcets Research Clinic in Shiraz (south-west Iran) and included the patients referred from 1990-1999. The patients' clinical records, images, CSF analyses, and electrodiagnostic studies were reviewed. Eighteen (15 males and 3 females) out of 690 Behcet s patients (2.6%, 95% CI = 1.4-3.8%) were found to have neurological involvement. The mean +/- standard deviation age of these patients was 34.7 +/- 8.6 years. All fulfilled the criteria of the International Study Group of Behcet s Disease. Central nervous system involvement was more common than peripheral nervous system manifestations. Headache, weakness, tingling, and numbness were the most common symptoms. Hyperreflexia, upward plantar reflex, and somatosensory findings were the most frequent signs. Hemispheral and brainstem stroke-like syndromes and cerebral venous thrombosis were the major neurologic presentations. There were also cases of myelitic, pure meningoencephalitic, amyotrophic lateral sclerosis-like, multiple sclerosis-like, and Guillain Barre syndromes. Neuro-Behcets disease must be considered in the differential diagnosis of stroke in young adults, chronic meningitis, intracranial hypertension, multiple sclerosis, myelopathies, and peripheral neuropathies. (author)

  1. [Ebola: characterization, history and cutaneous manifestations].

    Science.gov (United States)

    Kolbach, Marianne; Carrasco-Zuber, Juan Eduardo; Vial-Letelier, Verónica

    2015-11-01

    Ebola virus (EV) is one of the most virulent human pathogens. Fruits bats are its natural reservoir, the transmission to humans is across wild animals (especially primates) and the propagation in human populations is through bodily fluid contact. The actual outbreak started in December 2013 and crossed continental borders. Up to now, there are 17,145 suspected and confirmed cases with 6,070 deaths, resulting a total case fatality rate of 35%. Clinical manifestations can be divided in 3 phases. In phase I, symptoms are similar to flu, which may appear in a range of 2 to 21 days. In phase II which occurs in over 50% of cases, visceral symptoms and mucocutaneous manifestations appear within 4 and 5 days of the onset of symptoms. The main symptoms are a macular or maculopapular non-pruritic rash, desquamation and mucosal involvement of eyes, mouth and pharynx. In phase III, recovery or death occurs. The diagnosis is made on clinical grounds, epidemiological suspicion and a positive polymerase chain reaction (PCR) test. The treatment is supportive. If there is a suspected case, it should be notified immediately and all relevant safety measures should be instituted. PMID:26757869

  2. The Manifestly Gauge Invariant Exact Renormalisation Group

    CERN Document Server

    Rosten, O J

    2005-01-01

    We construct a manifestly gauge invariant Exact Renormalisation Group (ERG) whose form is suitable for computation in SU(N) Yang-Mills theory, beyond one-loop. An effective cutoff is implemented by embedding the physical SU(N) theory in a spontaneously broken SU(N|N) Yang-Mills theory. To facilitate computations within this scheme, which proceed at every step without fixing the gauge, we develop a set of diagrammatic techniques. As an initial test of the formalism, the one-loop SU(N) Yang-Mills beta-function, beta_1, is computed, and the standard, universal answer is reproduced. It is recognised that the computational technique can be greatly simplified. Using these simplifications, a partial proof is given that, to all orders in perturbation theory, the explicit dependence of perturbative $\\beta$-function coefficients, beta_n, on certain non-universal elements of the manifestly gauge invariant ERG cancels out. This partial proof yields an extremely compact, diagrammatic form for the surviving contributions t...

  3. Periodontal manifestations of von Recklinghausen neuro fibromatosis.

    Science.gov (United States)

    Shetty, Bhavya; Umesh, Y; Kranti, K; Seshan, Hema

    2013-03-01

    Neurofibroma is an uncommon benign tumor of the oral cavity derived from the cells that constitute the nerve sheath neurofibromatosis type 1 (NF1), also known as von Recklinghausen's disease, is the most common type of neurofibromatosis and accounts for about 90% of all cases. It is one of the most frequent human genetic diseases, with the prevalence of one case in 3,000 births. Neurofibroma is seen either as a solitary lesion or as part of the generalized syndrome of neurofibromatosis. The solitary form does not differ from the disseminated form or the multiple form of the disease, except that systemic and hereditary factors present in the disseminated form are absent in the solitary type. Oral cavity involvement by a solitary and peripheral plexiform neurofibroma in patients with no other signs of neurofibromatosis is uncommon. The expressivity of NF1 is extremely variable, with manifestations ranging from mild lesions to several complications and functional impairment. Oral manifestations can be found in almost 72% of NF1 patients. This is a case report of a 40-year-old lady with a history of multiple faint rounded densities in the skin, chest pain occasionally since 8 months and breathlessness since 1 year and swelling of the right side of the angle of the mandible with limited mouth opening. PMID:23869137

  4. The public manifestations of the audience

    Directory of Open Access Journals (Sweden)

    Roger de la Garde

    2011-12-01

    Full Text Available Mobile communication has confirmed our entry in the Post-Network Era (in particular, but not exclusively, through television programming. This state of affairs has not only challenged the economics of the television industry by rendering the “capture” of audiences (principally through programming more complex, and random, but also the basic notion of audience itself. In so doing, this Post-Network Era has re-activated, but in a more dialectical fashion, the earlier debate that accompanied the spread of cultural industries and the introduction of the Network Era, when and where “audiences” became a substitute for “publics”, “ratings” for “popular approval”, and “opinion polls” for “public debates”. The present Era offers the occasion to reflect on how “audiences” were and are constructed, how they manifest themselves, and what impact these constructions and manifestations have held on our conception, and research, of “publics” (as in the French tradition of “les publics” and “auditoire”, of “mass” and “mob”.

  5. Cutaneous manifestations of gastrointestinal disease: part I.

    Science.gov (United States)

    Shah, Kejal R; Boland, C Richard; Patel, Mahir; Thrash, Breck; Menter, Alan

    2013-02-01

    Cutaneous findings are not uncommonly a concomitant finding in patients afflicted with gastrointestinal (GI) diseases. The dermatologic manifestations may precede clinically evident GI disease. Part I of this 2-part CME review focuses on dermatologic findings as they relate to hereditary and nonhereditary polyposis disorders and paraneoplastic disorders. A number of hereditary GI disorders have an increased risk of colorectal carcinomas. These disorders include familial adenomatous polyposis, Peutz-Jeghers syndrome, and juvenile polyposis syndrome. Each disease has its own cutaneous signature that aids dermatologists in the early diagnosis and detection of hereditary GI malignancy. These disease processes are associated with particular gene mutations that can be used in screening and to guide additional genetic counseling. In addition, there is a group of hamartomatous syndromes, some of which are associated with phosphatase and tensin homolog (PTEN) gene mutations, which present with concurrent skin findings. These include Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Cronkhite-Canada syndrome. Finally, paraneoplastic disorders are another subcategory of GI diseases associated with cutaneous manifestations, including malignant acanthosis nigricans, Leser-Trélat sign, tylosis, Plummer-Vinson syndrome, necrolytic migratory erythema, perianal extramammary Paget disease, carcinoid syndrome, paraneoplastic dermatomyositis, and paraneoplastic pemphigus. Each of these disease processes have been shown to be associated with an increased risk of GI malignancy. This underscores the important role of dermatologists in the diagnosis, detection, monitoring, and treatment of these disorders while consulting and interacting with their GI colleagues. PMID:23317980

  6. Mucocutaneous manifestations of acquired hypoparathyroidism: An observational study

    OpenAIRE

    Somenath Sarkar; Modhuchanda Mondal; Kapildev Das; Arpit Shrimal

    2012-01-01

    Hypoparathyroidism is a disorder of calcium and phosphorus metabolism due to decreased secretion of parathyroid hormone. Hypoparathyroidism can be hereditary and acquired. Acquired hypoparathyroidism usually occurs following neck surgery (thyroid surgery or parathyroid surgery). Along with systemic manifestations, hypoparathyroidism produces some skin manifestations. Lack of study regarding mucocutaneous manifestations of acquired hypoparathyroidism prompted us to undertake this study. To eva...

  7. The bivalve Anopaea (Inoceramidae) from the Upper Jurassic-lowermost Cretaceous of Mexico

    Science.gov (United States)

    Zell, Patrick; Crame, J. Alistair; Stinnesbeck, Wolfgang; Beckmann, Seija

    2015-07-01

    In Mexico, the Upper Jurassic to lowermost Cretaceous La Casita and coeval La Caja and La Pimienta formations are well-known for their abundant and well-preserved marine vertebrates and invertebrates. The latter include conspicuous inoceramid bivalves of the genus Anopaea not formally described previously from Mexico. Anopaea bassei (Lecolle de Cantú, 1967), Anopaea cf. stoliczkai (Holdhaus, 1913), Anopaea cf. callistoensis Crame and Kelly, 1995 and Anopaea sp. are rare constituents in distinctive Tithonian-lower Berriasian levels of the La Caja Formation and one Tithonian horizon of the La Pimienta Formation. Anopaea bassei was previously documented from the Tithonian of central Mexico and Cuba, while most other members of Anopaea described here are only known from southern high latitudes. The Mexican assemblage also includes taxa which closely resemble Anopaea stoliczkai from the Tithonian of India, Indonesia and the Antarctic Peninsula, and Anopaea callistoensis from the late Tithonian to ?early Berriasian of the Antarctic Peninsula. Our new data expand the palaeogeographical distribution of the high latitude Anopaea to the Gulf of Mexico region and substantiate faunal exchange, in the Late Jurassic-earliest Cretaceous, between Mexico and the Antarctic Realm.

  8. Irradiated bivalve mollusks: Use of EPR spectroscopy for identification and dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Alberti, Angelo, E-mail: aalberti@isof.cnr.it [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy); Chiaravalle, Eugenio [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Fuochi, Piergiorgio; Macciantelli, Dante [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy); Mangiacotti, Michele, E-mail: michelemangiacotti@libero.it [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Marchesani, Giuliana [Istituto Zooprofilattico Sperimentale della Puglia e Basilicata, Via Manfredonia 20, Foggia I-71100 (Italy); Plescia, Elena [CNR-ISOF, Area della Ricerca di Bologna, Via P. Gobetti 101, Bologna I-40129 (Italy)

    2011-12-15

    High energy radiation treatment of foodstuff for microbial control and shelf-life extension is being used in many countries. However, for consumer protection and information, the European Union has adopted the Directives 1999/2/EC and 1999/3/EC to harmonize the rules concerning the treatment and trade of irradiated foods in EU countries. Among the validated methods to detect irradiated foods the EU directives also include Electron Paramagnetic Resonance (EPR/ESR) spectroscopy. We describe herein the use of EPR for identification of four species of bivalve mollusks, i.e. brown Venus shells (Callista chione), clams (Tapes semidecussatus), mussels (Mytilus galloprovincialis) and oysters (Ostrea edulis) irradiated with {sup 60}Co {gamma}-rays. EPR could definitely identify irradiated seashells due to the presence of long-lived free radicals, primarily CO{sub 2}{sup -}, CO{sub 3}{sup 3-}, SO{sub 2}{sup -} and SO{sub 3}{sup -} radical anions. The presence of other organic free radicals, believed to originate from conchiolin, a scleroprotein present in the shells, was also ascertained. The use of one of these radicals as a marker for irradiation of brown Venus shells and clams can be envisaged. We also propose a dosimetric protocol for the reconstruction of the administered dose in irradiated oysters. - Highlights: > EPR spectroscopy is confirmed a valuable identification tool for irradiated mollusks. > A conchiolin-derived radical can be used as irradiation marker for some mollusks. > A reliable protocol is outlined for dose reconstruction of irradiated oysters.

  9. Irradiated bivalve mollusks: Use of EPR spectroscopy for identification and dosimetry

    International Nuclear Information System (INIS)

    High energy radiation treatment of foodstuff for microbial control and shelf-life extension is being used in many countries. However, for consumer protection and information, the European Union has adopted the Directives 1999/2/EC and 1999/3/EC to harmonize the rules concerning the treatment and trade of irradiated foods in EU countries. Among the validated methods to detect irradiated foods the EU directives also include Electron Paramagnetic Resonance (EPR/ESR) spectroscopy. We describe herein the use of EPR for identification of four species of bivalve mollusks, i.e. brown Venus shells (Callista chione), clams (Tapes semidecussatus), mussels (Mytilus galloprovincialis) and oysters (Ostrea edulis) irradiated with 60Co γ-rays. EPR could definitely identify irradiated seashells due to the presence of long-lived free radicals, primarily CO2-, CO33-, SO2- and SO3- radical anions. The presence of other organic free radicals, believed to originate from conchiolin, a scleroprotein present in the shells, was also ascertained. The use of one of these radicals as a marker for irradiation of brown Venus shells and clams can be envisaged. We also propose a dosimetric protocol for the reconstruction of the administered dose in irradiated oysters. - Highlights: → EPR spectroscopy is confirmed a valuable identification tool for irradiated mollusks. → A conchiolin-derived radical can be used as irradiation marker for some mollusks. → A reliable protocol is outlined for dose reconstruction of irradiated oysters.

  10. Protandric hermaphroditism in the whale-fall bivalve mollusc Idas washingtonia

    Science.gov (United States)

    Tyler, Paul A.; Marsh, Leigh; Baco-Taylor, Amy; Smith, Craig R.

    2009-09-01

    Whale falls provide abundant but relatively ephemeral, sulphide-rich habitat islands on the deep-sea floor. To explore life-history adaptations to whale-fall habitats, we examined the reproductive biology of Idas washingtonia, a bathymodiolin mussel occurring in abundance on sunken whale skeletons in the deep northeast Pacific Ocean. Analysis of the reproductive biology of I. washingtonia demonstrates strong evidence of protandric hermaphroditism. Developing males were recognised in individuals as small as 1.7 mm shell length and spermatogenesis continued until ˜7 mm length. At >6.5 mm, males were generally spent and the first previtellogenic oocytes were observed. Although developing females were found as small as 4.5 mm shell length, most well-developed females were >6 mm shell length. Overall, females only formed ˜12% of the population. As with other modiolid bivalves, fecundity was high and the egg size whale falls even though these may have been severely reduced in abundance since the peak of commercial whaling activity in the 20th century.

  11. Bioremediation of metal-rich effluents: could the invasive bivalve work as a biofilter?

    Science.gov (United States)

    Rosa, Inês Correia; Costa, Raquel; Gonçalves, Fernando; Pereira, Joana Luísa

    2014-09-01

    Industrial effluents are important sources of contamination of water and sediments, frequently causing serious damage at different levels of biological organization. Management and treatment of harmful industrial wastes is thus a major concern. Metal-bearing effluents, such as acid mine drainage (AMD), are particularly problematic because metals can easily bioaccumulate in organisms and biomagnify across the trophic chain. Several solutions have been proposed to treat AMD, including active methods involving the addition of neutralizing agents and passive techniques that use natural energy sources for remediation. However, increasing environmental and economic requirements lead the constant search for more sustainable solutions. The present study explores the possibility of using , an invasive freshwater bivalve, as a bioremediation tool using AMD as a model, metal-bearing effluent. The study compares untreated and biotreated effluents at two dilution levels (4 and 10% v/v) following two distinct approaches: (i) chemical characterization of the metal concentrations in water complemented by determination of the accumulation in the clams' soft tissues and shells; and (ii) ecotoxicity assessment using standard organisms (the bacterium , the microalgae , and the cladoceran ). Significant removal of metals from water was recorded for both effluent dilutions, with higher purification levels found for the 4% effluent. The environmental toxicity of the effluents generally decreased after the treatment with the clams. Thus, this study provides evidence for the suitability of as a bioremediator for metal-bearing effluents, especially if the treatment can be materialized in a multistage configuration system. PMID:25603239

  12. Metabolic and histopathological alterations in the marine bivalve Mytilus galloprovincialis induced by chronic exposure to acrylamide.

    Science.gov (United States)

    Larguinho, Miguel; Cordeiro, Ana; Diniz, Mário S; Costa, Pedro M; Baptista, Pedro V

    2014-11-01

    Although the neurotoxic and genotoxic potential of acrylamide has been established in freshwater fish, the full breadth of the toxicological consequences induced by this xenobiotic has not yet been disclosed, particularly in aquatic invertebrates. To assess the effects of acrylamide on a bivalve model, the Mediterranean mussel (Mytilus galloprovincialis), two different setups were accomplished: 1) acute exposure to several concentrations of waterborne acrylamide to determine lethality thresholds of the substance and 2) chronic exposure to more reduced acrylamide concentrations to survey phases I and II metabolic endpoints and to perform a whole-body screening for histopathological alterations. Acute toxicity was low (LC50≈400mg/L). However, mussels were responsive to prolonged exposure to chronic concentrations of waterborne acrylamide (1-10mg/L), yielding a significant increase in lipid peroxidation plus EROD and GST activities. Still, total anti-oxidant capacity was not exceeded. In addition, no neurotoxic effects could be determined through acetylcholine esterase (AChE) activity. The findings suggest aryl-hydrocarbon receptor (Ahr)-dependent responses in mussels exposed to acrylamide, although reduced comparatively to vertebrates. No significant histological damage was found in digestive gland or gills but female gonads endured severe necrosis and oocyte atresia. Altogether, the results indicate that acrylamide may induce gonadotoxicity in mussels, although the subject should benefit from further research. Altogether, the findings suggest that the risk of acrylamide to aquatic animals, especially molluscs, may be underestimated. PMID:25262075

  13. Polonium-210 in marine mussels (bivalve molluscs) inhabiting the southern coast of India.

    Science.gov (United States)

    Khan, M Feroz; Wesley, S Godwin; Rajan, M P

    2014-12-01

    The present study focused on the determination of the alpha-emitter, (210)Po, in two species of marine mussels (bivalve molluscs) commonly available in the southern coastal region of India. The brown mussel, Perna indica was collected from the west coast and the green mussel, Perna viridis from the east coast. The concentration of (210)Po was related to the allometry (length of shell, wet/dry weight of shell/soft tissue) of the mussels and significant results were found. The study period focused on three seasons namely, pre-monsoon, monsoon and post-monsoon for a 1-year period (2010-2011). The results revealed higher activity levels in smaller-sized mussels compared to larger ones. Marked variation in (210)Po activity concentration was noted in the whole-body soft tissues between seasons and sampling site (p mussels was performed using the ERICA Assessment tool. The chronic exposure to mussels due to (210)Po was found to be lesser than the global benchmark dose rate of 10 μGy h(-1). The effective ingestion dose to adults who intake mussels was estimated to be in the range 5.1-34.9 μSv y(-1). The measurement contributes to the furthering of knowledge of (210)Po, since no data exist in this region. PMID:25042075

  14. Stable isotopic composition of bivalve shell organic matrix: Mytilus edulis collected along the Scheldt estuary

    Science.gov (United States)

    Mas, R.; Claeys, P.; Keppens, E.; Dehairs, F.

    2009-04-01

    Bivalve shells are biostructures composed of a mineral and an organic phase. For paleoclimatology applications, the mineral part (carbonates) is most widely studied. In contrast, understanding of the composition and the proxy-function of the organic matrix is much less developed. The quantity of organic matrix in shells is relatively small compared to the mineral phase (a few wt %) and the biochemical composition is quite complex, consisting mainly of sugars and proteins. Lipids, which represent a small fraction of the organic matrix, are rather poorly known. We studied the potential of stable isotope composition (C, N, H) of bulk organic matrix and specific lipid compounds of Mytilis edulis shells, as environmental and climatic proxies, with special focus on the effects due to changing salinity. Mytilus specimens were collected along the salinity gradient of the Scheldt estuary (The Netherlands) and we analysed the isotopic composition of the organic matrix and associated specific lipid compounds and related these to averaged physico-chemical characteristics of the water, in particular salinity. We discuss these relationships in the light of their usefulness as proxies for reconstructing past environmental conditions.

  15. Bioaccumulation efficiency, tissue distribution, and environmental occurrence of hepatitis E virus in bivalve shellfish from France.

    Science.gov (United States)

    Grodzki, Marco; Schaeffer, Julien; Piquet, Jean-Côme; Le Saux, Jean-Claude; Chevé, Julien; Ollivier, Joanna; Le Pendu, Jacques; Le Guyader, Françoise S

    2014-07-01

    Hepatitis E virus (HEV), an enteric pathogen of both humans and animals, is excreted by infected individuals and is therefore present in wastewaters and coastal waters. As bivalve molluscan shellfish are known to concentrate viral particles during the process of filter feeding, they may accumulate this virus. The bioaccumulation efficiencies of oysters (Crassostrea gigas), flat oysters (Ostrea edulis), mussels (Mytilus edulis), and clams (Ruditapes philippinarum) were compared at different time points during the year. Tissue distribution analysis showed that most of the viruses were concentrated in the digestive tissues of the four species. Mussels and clams were found to be more sensitive to sporadic contamination events, as demonstrated by rapid bioaccumulation in less than 1 h compared to species of oysters. For oysters, concentrations increased during the 24-h bioaccumulation period. Additionally, to evaluate environmental occurrence of HEV in shellfish, an environmental investigation was undertaken at sites potentially impacted by pigs, wild boars, and human waste. Of the 286 samples collected, none were contaminated with hepatitis E virus, despite evidence that this virus is circulating in some French areas. It is possible that the number of hepatitis E viral particles discharged into the environment is too low to detect or that the virus may have a very short period of persistence in pig manure and human waste. PMID:24795382

  16. Commensal associations and benthic habitats shape macroevolution of the bivalve clade Galeommatoidea.

    Science.gov (United States)

    Li, Jingchun; Ó Foighil, Diarmaid; Strong, Ellen E

    2016-07-13

    The great diversity of marine life has been shaped by the interplay between abiotic and biotic factors. Among different biotic interactions, symbiosis is an important yet less studied phenomenon. Here, we tested how symbiotic associations affected marine diversification, using the bivalve superfamily Galeommatoidea as a study system. This superfamily contains large numbers of obligate commensal as well as free-living species and is therefore amenable to comparative approaches. We constructed a global molecular phylogeny of Galeommatoidea and compared macroevolutionary patterns between free-living and commensal lineages. Our analyses inferred that commensalism/sediment-dwelling is likely to be the ancestral condition of Galeommatoidea and that secondary invasions of hard-bottom habitats linked to the loss of commensalism. One major clade containing most of the free-living species exhibits a 2-4 times higher diversification rate than that of the commensals, likely driven by frequent niche partitioning in highly heterogeneous hard-bottom habitats. However, commensal clades show much higher within-clade morphological disparity, likely promoted by their intimate associations with diverse hosts. Our study highlights the importance of interactions between different ecological factors in shaping marine macroevolution and that biotic factors cannot be ignored if we wish to fully understand processes that generate marine biodiversity. PMID:27383818

  17. Zachsia zenkewitschi (Teredinidae), a Rare and Unusual Seagrass Boring Bivalve Revisited and Redescribed.

    Science.gov (United States)

    Shipway, J R; O'Connor, R; Stein, D; Cragg, S M; Korshunova, T; Martynov, A; Haga, T; Distel, D L

    2016-01-01

    The sea-grass borer Zachsia zenkewitschi belongs to a group of economically and ecologically important bivalves, commonly referred to as shipworms. The sole recognized representative of the genus Zachsia, this species displays an unusual life history and reproductive strategy that is now understood to include: environmental sex determination of free swimming larvae, extreme sexual and size dimorphism between males and females, internal fertilization, maintenance of often large harems of male dwarfs within a specialized cavity of the female mantle, and complex maternal care of larvae in specialized brood pouches within the gill. It is also the only shipworm species known to burrow in sea grass rhizomes rather than terrestrial wood. Although Z. zenkewitschi is rare and little studied, understanding of its biology and anatomy has evolved substantially, rendering some aspects of its original description inaccurate. Moreover, no existing type specimens are known for this species. In light of these facts, we designate a neotype from among specimens recently collected at the type location, and undertake a re-description of this species, accounting for recent reinterpretation of its life history and functional anatomy. PMID:27171209

  18. Marine bivalve geochemistry and shell ultrastructure from modern low pH environments

    Directory of Open Access Journals (Sweden)

    S. Hahn

    2011-10-01

    Full Text Available Bivalve shells can provide excellent archives of past environmental change but have not been used to interpret ocean acidification events. We investigated carbon, oxygen and trace element records from different shell layers in the mussels Mytilus galloprovincialis (from the Mediterranean and M. edulis (from the Wadden Sea combined with detailed investigations of the shell ultrastructure. Mussels from the harbour of Ischia (Mediterranean, Italy were transplanted and grown in water with mean pHT 7.3 and mean pHT 8.1 near CO2 vents on the east coast of the island of Ischia. The shells of transplanted mussels were compared with M. edulis collected at pH ~8.2 from Sylt (German Wadden Sea. Most prominently, the shells recorded the shock of transplantation, both in their shell ultrastructure, textural and geochemical record. Shell calcite, precipitated subsequently under acidified seawater responded to the pH gradient by an in part disturbed ultrastructure. Geochemical data from all test sites show a strong metabolic effect that exceeds the influence of the low-pH environment. These field experiments showed that care is needed when interpreting potential ocean acidification signals because various parameters affect shell chemistry and ultrastructure. Besides metabolic processes, seawater pH, factors such as salinity, water temperature, food availability and population density all affect the biogenic carbonate shell archive.

  19. Structure and Classification of Haemocytes in the Bivalve Mollusc Meretrix meretrix

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yanyan; REN Sulian; WANG Dexiu; SONG Weibo

    2006-01-01

    Light and electron microscopic studies were carried out in order to characterize haemocytes in the bivalve mollusc Meretrix meretrix. According to nucleus and cytoplasm characters, four types of haemocytes were recognized: agranular haemocytes, lymphoid haemocyte, large granular and small granular haemocytes. Agranular hamocyte is the main cell type,accounting for 75%. It is agranular with rich organelles in cytoplasm, including mitochondria, golgi body and endoplasmic reticulum. Glycogen deposits were usually found in this cell type. The number of lymphoid haemocyte accounts for 1% -2%. This cell type is agranular and shows a high ratio of nucleus to cytoplasm. A few organelles were found. High electrondense granules with diameters of 0.2 - 0.5 μm and rich organelles were found in small granular haemocyte. The proportion of this cell type is about 15%. Rich granules of high electron-dense with diameters of 0.8- 2.4μm were found in large granular haemocyte. The proportion of this cell type is about 10%, and the quantity of organelles is the least.

  20. The Shell of the Invasive Bivalve Species Dreissena polymorpha: Biochemical, Elemental and Textural Investigations.

    Directory of Open Access Journals (Sweden)

    Françoise Immel

    Full Text Available The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an external thin layer, the characteristics of which differ from what was described in earlier publication. We show that the shell selectively concentrates some heavy metals, in particular uranium, which predisposes D. polymorpha to local bioremediation of this pollutant. We establish the biochemical signature of the shell matrix, demonstrating that it interacts with the in vitro precipitation of calcium carbonate and inhibits calcium carbonate crystal formation, but these two properties are not strongly expressed. This matrix, although overall weakly glycosylated, contains a set of putatively calcium-binding proteins and a set of acidic sulphated proteins. 2D-gels reveal more than fifty proteins, twenty of which we identify by MS-MS analysis. We tentatively link the shell protein profile of D. polymorpha and the peculiar recent evolution of this invasive species of Ponto-Caspian origin, which has spread all across Europe in the last three centuries.

  1. The Shell of the Invasive Bivalve Species Dreissena polymorpha: Biochemical, Elemental and Textural Investigations

    Science.gov (United States)

    Broussard, Cédric; Catherinet, Bastien; Plasseraud, Laurent; Alcaraz, Gérard; Bundeleva, Irina; Marin, Frédéric

    2016-01-01

    The zebra mussel Dreissena polymorpha is a well-established invasive model organism. Although extensively used in environmental sciences, virtually nothing is known of the molecular process of its shell calcification. By describing the microstructure, geochemistry and biochemistry/proteomics of the shell, the present study aims at promoting this species as a model organism in biomineralization studies, in order to establish a bridge with ecotoxicology, while sketching evolutionary conclusions. The shell of D. polymorpha exhibits the classical crossed-lamellar/complex crossed lamellar combination found in several heterodont bivalves, in addition to an external thin layer, the characteristics of which differ from what was described in earlier publication. We show that the shell selectively concentrates some heavy metals, in particular uranium, which predisposes D. polymorpha to local bioremediation of this pollutant. We establish the biochemical signature of the shell matrix, demonstrating that it interacts with the in vitro precipitation of calcium carbonate and inhibits calcium carbonate crystal formation, but these two properties are not strongly expressed. This matrix, although overall weakly glycosylated, contains a set of putatively calcium-binding proteins and a set of acidic sulphated proteins. 2D-gels reveal more than fifty proteins, twenty of which we identify by MS-MS analysis. We tentatively link the shell protein profile of D. polymorpha and the peculiar recent evolution of this invasive species of Ponto-Caspian origin, which has spread all across Europe in the last three centuries. PMID:27213644

  2. [Psychiatric manifestations by prions. A narrative review].

    Science.gov (United States)

    Carrillo Robles, Daniel; García Maldonado, Gerardo

    2016-01-01

    Prion diseases are a group of rare and rapidly progressive neurodegenerative conditions that may cause neuropsychiatric symptoms. This group of diseases has been described since the 18(th) century, but they were recognized decades later, when it became clear that the humans were affected by infected animals. There was controversy when the problem was attributed to a single protein with infective capacity. The common pathological process is characterized by the conversion of the normal cellular prion protein into an abnormal form. In humans, the illness has been classified as idiopathic, inherited and acquired through exposure to exogenous material containing abnormal prions. The most prominent neurological manifestation of prion diseases is the emergence of a rapidly progressive dementia, mioclonus associated with cerebellar ataxia and also extra pyramidal symptoms. Psychiatric symptoms occur in early stages of the illness and can contribute to timely diagnosis of this syndrome. Psychiatric symptoms have traditionally been grouped in three categories: affective symptoms, impaired motor function and psychotic symptoms. Such events usually occur during the prodromal period prior to the neurological manifestations and consists in the presence of social isolation, onset of delusions, irritability/aggression, visual hallucinations, anxiety and depression, and less frequent first-rank symptoms among others. Definite diagnosis requires post mortem examination. The possibility that a large number of cases may occur in the next years or that many cases have not been considered with this diagnosis is a fact. In our opinion, psychiatrists should be aware of symptoms of this disease. The main objective of this research consisted of assessing the correlation between this disturbance and neuro-psychiatric symptoms and particularly if this psychiatric manifestations integrate a clinical picture suggestive for the diagnosis of these diseases, but firstly reviewed taxonomic

  3. Atypical Radiological Manifestation of Pulmonary Metastatic Calcification

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Eun Hae; Kim, Eun Sun; Kim, Chul Hwan; Ham, Soo Youn; Oh, Yu Whan [Korea University College of Medicine, Seoul (Korea, Republic of)

    2008-04-15

    Metastatic pulmonary calcification is a condition of calcium deposition in the normal pulmonary parenchyma, and this is secondary to abnormal calcium metabolism without any prior soft tissue damage. The predisposing factors for this condition include chronic renal failure, hypercalcemia and increased tissue alkalinity. The most common radiologic manifestation consists of poorly defined nodular opacities in the upper lung zone. These opacities reflect the deposition of calcium salts in the pulmonary interstitium. We present here a case of metastatic pulmonary calcification in a patient who recovered from pneumonia with sepsis and whose high-resolution CT (HRCT) images demonstrated localized parenchymal airspace calcification that was limited to the bilateral lower lobes. These lower lobes had been involved with pneumonic consolidation without calcification, as seen on the previous CT scan. In summary, we report here on an atypical presentation of metastatic pulmonary calcification that showed dense airspace consolidation localized to the bilateral lower lobes in a patient with primary hyperparathyroidism and pneumonia.

  4. Manifestations of Top Compositeness at Colliders

    CERN Document Server

    Kumar, Kunal; Vega-Morales, Roberto

    2009-01-01

    We explore the possibility that the right-handed top quark is composite, identifying possible signatures of compositeness and how they might manifest themselves at the LHC and Tevatron. We perform a complete analysis of the dimension six modifications of the top coupling to gluons and find that cancellations among operators in the t\\bar{t} rate allow for very low compositeness scales, but this can be drastically improved by looking at kinematic distributions. Turning to the LHC, we examine four top production from a dimension six four-top operator and estimate the LHC with 100 {\\rm fb}^{-1} collected luminosity to be sensitive to compositeness scales as high as 5 TeV.

  5. Skin manifestations associated with kidney cancer.

    Science.gov (United States)

    Amin, Asim; Burgess, Earle F

    2016-06-01

    Kidney cancer is a heterogenous disease encompassing several distinct clinicopathologic entities with different underlying molecular aberrations and clinical outcomes. Renal cell carcinoma (RCC) has been shown to evoke immunologic responses that can impact the natural history of disease and clinical presentation. It is important to recognize atypical presentations of disease, including cutaneous manifestations. The incidence of skin metastases from RCC is low, yet needs to be appreciated in the appropriate setting; clinical presentation for these lesions is reviewed briefly. There are several hereditary syndromes that present with well characterized cutaneous lesions and are associated with an increased risk for RCC, including Von Hippel-Lindau and Birt-Hogg-Dubé syndromes. Given that these skin lesions may be the first presenting sign for RCC, timely recognition is of essence and both are discussed in some detail. Several therapeutic options based on immunomodulation are approved for the treatment of advanced RCC. Dermatologic toxicities observed with these agents are also briefly discussed. PMID:27178696

  6. Cerebellar stroke-manifesting as mania

    Directory of Open Access Journals (Sweden)

    Venkatesan Jagadesan

    2014-01-01

    Full Text Available Secondary mania resulting from cerebral Cortex are described commonly. But secondary mania produced by cerebellar lesions are relatively uncommon. This case report describes a patient who developed cerebellar stoke and manic features simultaneously. 28 years old male developed giddiness and projectile vomiting. Then he would lie down for about an hour only to find that he could not walk. He became quarrelsome. His Psycho motor activities and speech were increased. He was euphoric and was expressing grandiose ideas. Bender Gestalt Test showed signs of organicity. Score in Young mania relating scale was 32; productivity was low in Rorschach. Neurological examination revealed left cerebellar signs like ataxia and slurring of speech. Computed tomography of brain showed left cerebellar infarct. Relationship between Psychiatric manifestations and cerebellar lesion are discussed.

  7. Manifest Covariant Hamiltonian Theory of General Relativity

    CERN Document Server

    Cremaschini, Claudio

    2016-01-01

    The problem of formulating a manifest covariant Hamiltonian theory of General Relativity in the presence of source fields is addressed, by extending the so-called "DeDonder-Weyl" formalism to the treatment of classical fields in curved space-time. The theory is based on a synchronous variational principle for the Einstein equation, formulated in terms of superabundant variables. The technique permits one to determine the continuum covariant Hamiltonian structure associated with the Einstein equation. The corresponding continuum Poisson bracket representation is also determined. The theory relies on first-principles, in the sense that the conclusions are reached in the framework of a non-perturbative covariant approach, which allows one to preserve both the 4-scalar nature of Lagrangian and Hamiltonian densities as well as the gauge invariance property of the theory.

  8. Quantum manifestations of classical nonlinear resonances.

    Science.gov (United States)

    Wisniacki, Diego A; Schlagheck, Peter

    2015-12-01

    When an integrable classical system is perturbed, nonlinear resonances are born, grow, and eventually disappear due to chaos. In this paper the quantum manifestations of such a transition are studied in the standard map. We show that nonlinear resonances act as a perturbation that break eigenphase degeneracies for unperturbed states with quantum numbers that differ in a multiple of the order of the resonance. We show that the eigenphase splittings are well described by a semiclassical expression based on an integrable approximation of the Hamiltonian in the vicinity of the resonance. The morphology in phase space of these states is also studied. We show that the nonlinear resonance imprints a systematic influence in their localization properties. PMID:26764790

  9. Natural curvature for manifest T-duality

    International Nuclear Information System (INIS)

    We reformulate the manifestly T-dual description of the massless sector of the closed bosonic string, directly from the geometry associated with the (left and right) affine Lie algebra of the coset space Poincaré/Lorentz. This construction initially doubles not only the (spacetime) coordinates for translations but also those for Lorentz transformations (and their “dual”). As a result, the Lorentz connection couples directly to the string (as does the vielbein), rather than being introduced ad hoc to the covariant derivative as previously. This not only reproduces the old definition of T-dual torsion, but automatically gives a general, covariant definition of T-dual curvature (but still with some undetermined connections)

  10. Manifestly diffeomorphism invariant classical Exact Renormalization Group

    CERN Document Server

    Morris, Tim R

    2016-01-01

    We construct a manifestly diffeomorphism invariant Wilsonian (Exact) Renormalization Group for classical gravity, and begin the construction for quantum gravity. We demonstrate that the effective action can be computed without gauge fixing the diffeomorphism invariance, and also without introducing a background space-time. We compute classical contributions both within a background-independent framework and by perturbing around a fixed background, and verify that the results are equivalent. We derive the exact Ward identities for actions and kernels and verify consistency. We formulate two forms of the flow equation corresponding to the two choices of classical fixed-point: the Gaussian fixed point, and the scale invariant interacting fixed point using curvature-squared terms. We suggest how this programme may completed to a fully quantum construction.

  11. Pulmonary manifestations of inflammatory bowel disease.

    Science.gov (United States)

    Majewski, Sebastian; Piotrowski, Wojciech

    2015-12-10

    Bronchopulmonary signs and symptoms are examples of variable extraintestinal manifestations of the inflammatory bowel diseases (IBD). These complications of Crohn's disease (CD) and ulcerative colitis (UC) seem to be underrecognized by both pulmonary physicians and gastroenterologists. The objective of the present review was to gather and summarize information on this particular matter, on the basis of available up-to-date literature. Tracheobronchial involvement is the most prevalent respiratory presentation, whereas IBD-related interstitial lung disease is less frequent. Latent and asymptomatic pulmonary involvement is not unusual. Differential diagnosis should always consider infections (mainly tuberculosis) and drug-induced lung pathology. The common link between intestinal disease and lung pathology is unknown, but many hypotheses have been proposed. It is speculated that environmental pollution, common immunological mechanisms and predisposing genetic factors may play a role. PMID:26788078

  12. Unusual manifestation of Erdheim-Chester disease

    Directory of Open Access Journals (Sweden)

    Schlup Martin

    2011-06-01

    Full Text Available Abstract Background Erdheim-Chester disease (ECD is a rare multisystem non-Langerhans cell histiocytosis that is characterized histologically by xanthogranulomatous infiltrates and radiologically by symmetrical sclerosis of long bones. The xanthomatous process is characterized by prominent foamy histiocytes staining positive for CD68, occasionally for PS100 and negative for S100 and CD1a. Gastroenterological involvement is exceedingly rare. Case Presentation This case report describes the case of a 69-year-old man who presented otherwise well to the gastroenterology department with unspecific abdominal symptoms, nausea, vomiting and weight loss. ECD involving the gastrointestinal tract was confirmed clinically, radiologically and histologically. Conclusion Gastroenterological manifestation of ECD is rare but should be considered in the differential diagnosis in patients presenting with evidence of multi-organ disease and typical radiological features of Erdheim-Chester disease elsewhere.

  13. CT manifestations of adult mycoplasma pneumoniae pneumonia

    International Nuclear Information System (INIS)

    Objective: To study the conventional CT and HRCT manifestations of adult mycoplasma pneumoniae pneumonia. Methods: Conventional CT and HRCT were performed in 16 adult patients with mycoplasma pneumoniae pneumonia proven by serology. The CT images were retrospectively analyzed. Results: Areas of ground-glass opacity (GGO) were found in 12 cases. GGO showed lobular or patchy distribution in 9 cases. Air-space consolidation was observed in 8 cases, 'tree in bud' sign in 9, thickening of the interlobular septa in 3, and thickening of bronchovascular bundle in 1. 15 cases had two or more findings simultaneously. Conclusion: Mycoplasma pneumoniae pneumonia has some characteristic CT findings, which can help to distinguish it from bacterial pneumonia

  14. Preclinical detection of motor and nonmotor manifestations.

    Science.gov (United States)

    Tetrud, J W

    1991-08-01

    The advent of possible protective therapies for Parkinson's disease has created a need for methods of diagnosing the disease before the clinical features become fully evident. As a number of motor and nonmotor manifestations of the disease emerge months to years before a diagnosis can be made, a battery of clinical tests might be sufficient to identify individuals at an earlier stage than is currently possible using the standard history and physical examination. A list of questions regarding possible risk factors, specific symptoms, and observations of family members could be combined in a self-administered questionnaire that might identify individuals with a high probability of early, but otherwise undiagnosable, Parkinson's disease. Identification of subtle motor features is another possible screening method. For example, handwriting and speech are commonly affected prior to diagnosis; thus, automated analysis of these motor actions might also provide detection of incipient disease. PMID:1894144

  15. Patent foramen ovale: clinical manifestations and treatment.

    Science.gov (United States)

    Kedia, Gautam; Tobis, Jonathan; Lee, Michael S

    2008-01-01

    A persistent patent foramen ovale produces an intermittent intra-atrial right-to-left shunt and occurs in approximately 25% of the general population. Although the vast majority of people with patent foramen ovale are asymptomatic, a patent foramen ovale is believed to act as a pathway for chemicals or thrombus that can result in a variety of clinical manifestations, including stroke, migraine headache, decompression sickness, high-altitude pulmonary edema, and platypnea-orthodeoxia syndrome. The optimal management of patients with patent foramen ovale who experience cryptogenic stroke is unclear. Percutaneous closure appears to have a low risk profile and has been considered in high-risk patients who are not candidates for randomized clinical trials. Randomized clinical trials that are underway should help define the best management of patent foramen ovale, as well as the true safety and efficacy of percutaneous closure devices. PMID:18953276

  16. Clinical Manifestations of Type 1 Gaucher Disease

    Directory of Open Access Journals (Sweden)

    Shadab SALEHPOUR

    2012-12-01

    Full Text Available  How to Cite this Article: Salehpour Sh. Clinical Manifestations of Type 1 Gaucher Disease. Iran J Child Neurol Autumn 2012; 6:4 (suppl. 1:13-14.pls see PDF.References 1. Beutler E, Grabowski GA. Gaucher disease. In: Metabolic and molecular bases of inherited disease, Scriver CR, Beaudet AL, Sly WS, Valle D (Eds, McGraw-Hill, New York 2001: 3635. 2. Cox TM, Schofield JP.   Gaucher’s disease: clinical features  and   natural   history.   Baillieres   Clin Haematol. 1997 Dec;10(4:657-89.   

  17. Proteus syndrome: emphasis on the pulmonary manifestations

    International Nuclear Information System (INIS)

    Published articles on the radiologic aspects of Proteus syndrome are sparse. This report highlights the features of this disease with specific attention to the serious pulmonary manifestations that may occur at an early age. Two cases of Proteus syndrome and severe lung disease are presented, with complete autopsy in one case and correlative surgical pathologic data in the other. Multiple superficial and visceral vascular abnormalities were present in both cases. Both patients developed rapidly progressive diffuse cystic emphysematous pulmonary disease leading to the death of one patient at age 18 years and a heart-lung transplant in the other at age 8 1/2 years. Extensive gross pulmonary cysts were evident pathologically with diffuse panlobar emphysema microscopically. Studies of collagen and cultured fibroblasts in one patient revealed no abnormality. The early presentation, rapid progression and potentially lethal nature of lung involvement has not previously been emphasized. (orig.)

  18. CUTANEOUS MANIFESTATIONS ASSOCIATED WITH DIABETES MELLITUS

    Directory of Open Access Journals (Sweden)

    Satish

    2014-09-01

    Full Text Available Diabetes mellitus (DM refers to a group of common metabolic disorders that share the phenotype of hyperglycemia. The metabolic dysregulation associated with DM causes secondary pathophysiologic changes in multiple organ systems that impose a tremendous burden on the individual with diabetes and on the health care system. AIM: of the study was to evaluate presence and prevalence of common dermatoses in patients. 250 cases of D.M. with various cutaneous manifestations attending in and outpatient department of Dr. D. Y. Patil medical hospital were evaluated. Detailed history was taken as per proforma and patient investigated. Maximum incidence was seen between 40-70 yrs. of age and in middle class. Fungal infection constituted highest number which included dermatophytosis, candidiasis and pityriasis versicolor. No cutaneous reactions to therapy for diabetes were encountered in the present study.

  19. Manifestly diffeomorphism invariant classical Exact Renormalization Group

    Science.gov (United States)

    Morris, Tim R.; Preston, Anthony W. H.

    2016-06-01

    We construct a manifestly diffeomorphism invariant Wilsonian (Exact) Renor-malization Group for classical gravity, and begin the construction for quantum gravity. We demonstrate that the effective action can be computed without gauge fixing the diffeo-morphism invariance, and also without introducing a background space-time. We compute classical contributions both within a background-independent framework and by perturbing around a fixed background, and verify that the results are equivalent. We derive the exact Ward identities for actions and kernels and verify consistency. We formulate two forms of the flow equation corresponding to the two choices of classical fixed-point: the Gaussian fixed point, and the scale invariant interacting fixed point using curvature-squared terms. We suggest how this programme may completed to a fully quantum construction.

  20. HIV and Orthopaedics: Musculoskeletal Manifestations and Outcomes.

    Science.gov (United States)

    Pretell-Mazzini, Juan; Subhawong, Ty; Hernandez, Victor H; Campo, Rafael

    2016-05-01

    ➤Advances in combined antiretroviral therapy (cART) in recent years have transformed HIV infection into a chronic disease when treatment is available, increasing a patient's life expectancy and the chances that orthopaedic surgeons will encounter such patients in their clinical practice.➤Musculoskeletal manifestations in patients with HIV infection are common and sometimes are the initial presentation of the disease. Knowledge about neoplasms and associated conditions affecting muscle, bones, and joints is essential for successful management.➤Since the advent of cART, total joint arthroplasty has been shown to be a safe procedure; however, perioperative infection is still a small risk in patients with uncontrolled viral loads or CD4 counts of nutritional status, cART therapy, viral load count, and other comorbidities (hemophilia, infection among intravenous drug users, etc.) should be considered when treating these patients in order to optimize their clinical outcomes. PMID:27147691

  1. Gastrointestinal manifestations in myotonic muscular dystrophy

    Institute of Scientific and Technical Information of China (English)

    Massimo Bellini; Sonia Biagi; Cristina Stasi; Francesco Costa; Maria Gloria Mumolo; Angelo Ricchiuti; Santino Marchi

    2006-01-01

    Myotonic dystrophy (MD) is characterized by myotonic phenomena and progressive muscular weakness.Involvement of the gastrointestinal tract is frequent and may occur at any level. The clinical manifestations have previously been attributed to motility disorders caused by smooth muscle damage, but histologic evidence of alterations has been scarce and conflicting.A neural factor has also been hypothesized. In the upper digestive tract, dysphagia, heartburn, regurgitation and dyspepsia are the most common complaints, while in the lower tract, abdominal pain, bloating and changes in bowel habits are often reported. Digestive symptoms may be the first sign of dystrophic disease and may precede the musculo-skeletal features. The impairment of gastrointestinal function may be sometimes so gradual that the patients adapt to it with little awareness of symptoms. In such cases routine endoscopic and ultrasonographic evaluations are not sufficient and targeted techniques (electrogastrography, manometry,electromyography, functional ultrasonography,scintigraphy, etc.) are needed. There is a low correlation between the degree of skeletal muscle involvement and the presence and severity of gastrointestinal disturbances whereas a positive correlation with the duration of the skeletal muscle disease has been reported.The drugs recommended for treating the gastrointestinal complaints such as prokinetic, antidyspeptic drugs and laxatives, are mainly aimed at correcting the motility disorders.Gastrointestinal involvement in MD remains a complex and intriguing condition since many important problems are still unsolved. Further studies concentrating on genetic aspects, early diagnostic techniques and the development of new therapeutic strategies are needed to improve our management of the gastrointestinal manifestations of MD.

  2. Species composition, richness, and distribution of marine bivalve molluscs in Bahía de Mazatlán, México

    Science.gov (United States)

    Esqueda-González, María del Carmen; Ríos-Jara, Eduardo; Galván-Villa, Cristian Moises; Rodríguez-Zaragoza, Fabian Alejandro

    2014-01-01

    Abstract We describe the composition and distribution of bivalve molluscs from the sandy and rocky intertidal and the shallow subtidal environments of Bahía de Mazatlán, México. The bivalve fauna of the bay is represented by 89 living species in 28 families, including 37 new records and four range extensions: Lithophaga hastasia, Adula soleniformis, Mactrellona subalata, and Strigilla ervilia. The number of species increases from the upper (44) and lower intertidal (53) to the shallow subtidal (76), but only 11 (17%) have a wide distribution in the bay (i.e., found in all sampling sites and environments). The bivalve assemblages are composed of four main life forms: 27 epifaunal species, 26 infaunal, 16 semi-infaunal, and 20 endolithic. A taxonomic distinctness analysis identified the sampling sites and environments that contribute the most to the taxonomic diversity (species to suborder categories) of the bay. The present work increased significantly (31%) to 132 species previous inventories of bivalves of Bahía de Mazatlán. These species represent 34% of the bivalve diversity of the southern Golfo de California and approximately 15% of the Eastern Tropical Pacific region. PMID:24843252

  3. Mg isotopes in biocarbonates: new insight into vital effects associated to echinoderms and bivalves calcification

    Science.gov (United States)

    Planchon, F.; Hermans, J.; Borremans, C.; Dubois, P.; Poulain, C.; Paulet, Y.; Andre, L.

    2007-12-01

    Mg isotopes can be helpful tracers to reveal the fundamental pathways of Mg incorporation during biomineralisation. We report in this study a detailed characterisation of the Mg isotopic signatures of different biominerals: high magnesium calcitic skeletons of selected echinoderms (sea urchins and starfish) and low magnesium aragonitic shells of a bivalve species (clam). State of the art analytical procedures were applied including sample purification step followed by high precision measurements using MC-ICP-MS (Nu instrument) in dry plasma conditions. 26Mg/24Mg and 25Mg/24Mg are expressed as per mil deviations from the DSM3 (Dead Sea Metal 3) reference standard in delta notation (d26Mg and d25Mg). For echinoderms, we considered: (a) adult specimens of six starfish species (Asteria r., Marthasterias g., Anseropoda p., Asterina g., Echinaster s. and Henricia o.), sampled in Brittany (France); (b) a sea urchin species (Paracentrotus lividus) with field samples (Mediterranean Sea, Marseille, France) and culture specimen under T and S controlled conditions. In vivo endoskeletons display negative, but different d26Mg values of -3.06 for starfish (with uniform interspecies signatures) and -2.65 for sea urchin. Relative to seawater signature (-0.82), all echinoderms favour the incorporation of light isotopes during biocalcification. The d26Mg depletion is lower than theoretically expected from a inorganic calcite precipitation from seawater (at -3.5). These differences suggest that on its route from seawater to the shell, Mg isotopes are partly biologically fractionationated through "vital effects" leaving heavier Mg isotopic signatures. Taken into account that calcification in echinoderms is an intra- cellular process involving transient amorphous calcium carbonate (ACC) phase, the observed bio-fractionation factors can be related to: (1) changes in the isotopic composition of the precipitating intracellular fluids due to active pumping in and out of the cell; (2) a

  4. 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.

  5. Molluscs for Sale: Assessment of Freshwater Gastropods and Bivalves in the Ornamental Pet Trade.

    Science.gov (United States)

    Ng, Ting Hui; Tan, Siong Kiat; Wong, Wing Hing; Meier, Rudolf; Chan, Sow-Yan; Tan, Heok Hui; Yeo, Darren C J

    2016-01-01

    The ornamental pet trade is often considered a key culprit for conservation problems such as the introduction of invasive species (including infectious diseases) and overharvesting of rare species. Here, we present the first assessment of the biodiversity of freshwater molluscs in the ornamental pet trade in Singapore, one of the most important global hubs of the ornamental aquarium trade, and discuss associated conservation concerns. We recorded freshwater molluscs from ornamental pet shops and major exporters including non-ornamental species (e.g., hitchhikers, molluscs sold as fish feed). We recorded an unexpectedly high diversity-59 species-of freshwater bivalves and gastropods, with the majority (38 species or 64%) being from the Oriental region. In addition to morphological examination, we sequenced the DNA barcode region of mitochondrial CO1 and 16S genes to provide molecular data for the confirmation of the identification and for future re-identification. DNA barcodes were obtained for 50 species, and all but four were separated by > 3% uncorrected pairwise distances. The trade has been considered a main introduction pathway for non-native species to Singapore, and we found that out of 15 species in the trade as well as in the wild in Singapore, 12 are either introduced or of unknown origin, representing almost half of the known non-native freshwater molluscs in Singapore. Particularly prevalent are non-ornamental species: six hitchhikers on aquarium plants and six species sold as fish feed. We found that a quarter of the trade species have a history of introduction, which includes 11 known or potentially invasive species. We conclude that potential overharvesting is difficult to assess because only half of the trade species have been treated by IUCN. Of these, 21 species are of Least Concern and three are Data Deficient. Our checklist, with accompanying DNA barcodes, images, and museum vouchers, provides an important reference library for future monitoring

  6. Location is everything: evaluating the effects of terrestrial and marine resource subsidies on an estuarine bivalve.

    Science.gov (United States)

    Harding, Joel M S; Segal, Michelle R; Reynolds, John D

    2015-01-01

    Estuaries are amongst the world's most productive ecosystems, lying at the intersection between terrestrial and marine environments. They receive substantial inputs from adjacent landscapes but the importance of resource subsidies is not well understood. Here, we test hypotheses for the effects of both terrestrial- and salmon-derived resource subsidies on the diet (inferred from stable isotopes of muscle tissue), size and percent nitrogen of the soft-shell clam (Mya arenaria), a sedentary estuarine consumer. We examine how these relationships shift across natural gradients among 14 estuaries that vary in upstream watershed size and salmon density on the central coast of British Columbia, Canada. We also test how assimilation and response to subsidies vary at smaller spatial scales within estuaries. The depletion and enrichment of stable isotope ratios in soft-shell clam muscle tissue correlated with increasing upstream watershed size and salmon density, respectively. The effects of terrestrial- and salmon-derived subsidies were also strongest at locations near stream outlets. When we controlled for age of individual clams, there were larger individuals with higher percent nitrogen content in estuaries below larger watersheds, though this effect was limited to the depositional zones below river mouths. Pink salmon exhibited a stronger effect on isotope ratios of clams than chum salmon, which could reflect increased habitat overlap as spawning pink salmon concentrate in lower stream reaches, closer to intertidal clam beds. However, there were smaller clams in estuaries that had higher upstream pink salmon densities, possibly due to differences in habitat requirements. Our study highlights the importance of upstream resource subsidies to this bivalve species, but that individual responses to subsidies can vary at smaller scales within estuaries. PMID:25993002

  7. Location is everything: evaluating the effects of terrestrial and marine resource subsidies on an estuarine bivalve.

    Directory of Open Access Journals (Sweden)

    Joel M S Harding

    Full Text Available Estuaries are amongst the world's most productive ecosystems, lying at the intersection between terrestrial and marine environments. They receive substantial inputs from adjacent landscapes but the importance of resource subsidies is not well understood. Here, we test hypotheses for the effects of both terrestrial- and salmon-derived resource subsidies on the diet (inferred from stable isotopes of muscle tissue, size and percent nitrogen of the soft-shell clam (Mya arenaria, a sedentary estuarine consumer. We examine how these relationships shift across natural gradients among 14 estuaries that vary in upstream watershed size and salmon density on the central coast of British Columbia, Canada. We also test how assimilation and response to subsidies vary at smaller spatial scales within estuaries. The depletion and enrichment of stable isotope ratios in soft-shell clam muscle tissue correlated with increasing upstream watershed size and salmon density, respectively. The effects of terrestrial- and salmon-derived subsidies were also strongest at locations near stream outlets. When we controlled for age of individual clams, there were larger individuals with higher percent nitrogen content in estuaries below larger watersheds, though this effect was limited to the depositional zones below river mouths. Pink salmon exhibited a stronger effect on isotope ratios of clams than chum salmon, which could reflect increased habitat overlap as spawning pink salmon concentrate in lower stream reaches, closer to intertidal clam beds. However, there were smaller clams in estuaries that had higher upstream pink salmon densities, possibly due to differences in habitat requirements. Our study highlights the importance of upstream resource subsidies to this bivalve species, but that individual responses to subsidies can vary at smaller scales within estuaries.

  8. The estimation of DEB parameters for various Northeast Atlantic bivalve species

    Science.gov (United States)

    van der Veer, Henk W.; Cardoso, Joana F. M. F.; van der Meer, Jaap

    2006-08-01

    Dynamic energy budgets are used for the description of the energy flow through individual organisms from the assimilation of food to the utilisation for maintenance, growth, development and reproduction. In this paper, a procedure for estimation of the parameters of Kooijman's Dynamic Energy Budget (DEB) model is introduced and subsequently parameters are estimated for the following Northeast Atlantic bivalve species: the Baltic clam Macoma balthica (L.), the sandgaper Mya arenaria L., the cockle Cerastoderma edule (L.), the blue mussel Mytilus edulis L. and the Pacifc oyster Crassostrea gigas (Thunberg, 1793). For none of the species, a complete set of parameters could be compiled. A special protocol was developed to account for missing values and to achieve consistency between parameters. Species were similar in their optimal temperature range, as reflected in a common Arrhenius temperature of 5800 K, which corresponds with a Q 10 of 2. Differences between species were observed in width of the optimal temperature range. The taxonomic relatedness between species was reflected in similar volume-specific maintenance costs, costs for growth and almost similar maximum storage density of energy. Species differed in their maximum surface area-specific assimilation rate by a factor of 6 and in the fraction of energy allocated to reproduction (ranging from 0.15 to 0.50). These differences are reflected in the maximum theoretical total shell length of the species, which varied from about 3 cm in M. balthica, 6 cm in C. edule, 15 cm in M. arenaria and M. edulis and 45 cm in C. gigas.

  9. Mixed function oxygenases and xenobiotic detoxication/toxication systems in bivalve molluscs

    Science.gov (United States)

    Moore, M. N.; Livingstone, D. R.; Donkin, P.; Bayne, B. L.; Widdows, J.; Lowe, D. M.

    1980-03-01

    Components of a xenobiotic detoxication/toxication system involving mixed function oxygenases are present in Mytilus edulis. Our paper critically reviews the recent literature on this topic which reported the apparent absence of such a system in bivalve molluscs and attempts to reconcile this viewpoint with our own findings on NADPH neotetrazolium reductase, glucose-6-phosphate dehydrogenase, aldrin epoxidation and other reports of the presence of mixed function oxygenases. New experimental data are presented which indicate that some elements of the detoxication/toxication system in M. edulis can be induced by aromatic hydrocarbons derived from crude oil. This includes a brief review of the results of long-term experiments in which mussels were exposed to low concentrations of the water accommodated fraction of North Sea crude oil (7.7-68 µg 1-1) in which general stress responses such as reduced physiological scope for growth, cytotoxic damage to lysosomal integrity and cellular damage are considered as characteristics of the general stress syndrome induced by the toxic action of the xenobiotics. In addition, induction in the blood cells of microsomal NADPH neotetrazolium reductase (associated with mixed function oxygenases) and the NADPH generating enzyme glucose-6-phosphate dehydrogenase are considered to be specific biological responses to the presence of aromatic hydrocarbons. The consequences of this detoxication/toxication system for Mytilus edulis are discussed in terms of the formation of toxic electrophilic intermediate metabolites which are highly reactive and can combine with DNA, RNA and proteins with subsequent damage to these cellular constituents. Implications for neoplasms associated with the blood cells are also discussed. Finally, in view of the increased use of mussel species in pollutant monitoring programmes, the induction phenomenon which is associated with microsomal enzymes in the blood cells is considered as a possible tool for the

  10. Polonium-210 in marine mussels (bivalve molluscs) inhabiting the southern coast of India

    International Nuclear Information System (INIS)

    The present study focused on the determination of the alpha-emitter, 210Po, in two species of marine mussels (bivalve molluscs) commonly available in the southern coastal region of India. The brown mussel, Perna indica was collected from the west coast and the green mussel, Perna viridis from the east coast. The concentration of 210Po was related to the allometry (length of shell, wet/dry weight of shell/soft tissue) of the mussels and significant results were found. The study period focused on three seasons namely, pre-monsoon, monsoon and post-monsoon for a 1-year period (2010–2011). The results revealed higher activity levels in smaller-sized mussels compared to larger ones. Marked variation in 210Po activity concentration was noted in the whole-body soft tissues between seasons and sampling site (p < 0.05). The dose rate assessment for mussels was performed using the ERICA Assessment tool. The chronic exposure to mussels due to 210Po was found to be lesser than the global benchmark dose rate of 10 μGy h−1. The effective ingestion dose to adults who intake mussels was estimated to be in the range 5.1–34.9 μSv y−1. The measurement contributes to the furthering of knowledge of 210Po, since no data exist in this region. - Highlights: • Polonium-210 was quantified in two species of Mytilid mussels inhabiting southern coast of India. • Polonium-210 activity showed significant variation among size classes, between seasons and sampling site. • The internal dose rate to mussels and the dose assessment to the adult population were performed

  11. Improving shallow-water carbonate chemostratigraphy by means of rudist bivalve sclerochemistry

    Science.gov (United States)

    Huck, S.; Heimhofer, U.

    2015-09-01

    Deep-time shallow-marine carbonate platforms record distinct biotic responses to climatic and environmental stressors. Unfortunately, precise temporal assignment of these biotic responses is often problematical due to poor biostratigraphic control and/or a significant diagenetic overprint of the neritic bulk carbonate chemostratigraphic inventory. An accurate stratigraphic framework is essential to better understand the causal relation between biotic events recorded by carbonate platforms and environmental changes that, for instance, culminated in mass extinction events or prolonged episodes of oceanic anoxia. Here we provide an integrated carbon and strontium-isotope stratigraphy of the Early Cretaceous subtropical Provence carbonate platform in SE France that is based solely on pristine low-Mg calcite from rudist bivalves. Carbon-isotope data of geochemically screened rudist fragments enabled reconstruction of a characteristic Barremian pattern including the Mid-Barremian Event (MBE) that allowed for a precise correlation with stratigraphically well-constrained Tethyan shallow-water and hemipelagic reference sections. In order to evaluate ontogenetic carbon-isotope changes and the overall variability of the shell-derived carbon-isotope data, numerous sclerochronological carbon-isotope profiles of individual large rudist shells are presented. Strontium-isotope stratigraphy supports the carbon-isotope-based age of the studied sections, but also provides unequivocal evidence for a major hiatus in the depositional record covering large parts of the Late Barremian. In contrast to biostratigraphic and bulk carbonate chemostratigraphic archives, the here established chronostratigraphy of carbonate platform evolution in the southern Provence region demonstrates a twofold resurgence of rudist-rich carbonate platform production during the Early Aptian and arguably the latest Early Aptian.

  12. Effect of chronic selenium exposure on the freshwater bivalve Corbicula fluminea

    International Nuclear Information System (INIS)

    Selenium is essential for most of living organisms. In oxic to moderately oxic fresh-waters, Se exists predominantly in the (+VI) and (+IV) oxidation states as selenate (SeO42-) and selenite (SeO32-) respectively, whereas in the biota it is incorporated as Se(-II) into seleno-proteins or amino-acids, or as elemental selenium Se(0). At low concentrations, it acts against oxidative damages mainly as the glutathione peroxidase seleno-dependant, but it may be toxic at higher levels (for example, by replacing sulphur in important biomolecules). In filter feeders, such as the freshwater bivalve Corbicula fluminea, selected as biological model, the ventilation activity is a primary limiting step that controls the water influx and therefore the delivery of contaminants. Consequently, a series of short-term experiments were performed to study the effects of different dissolved Se concentrations and forms (selenite; selenate; selenomethionine) on the ventilation activity of Corbicula fluminea and Se tissular distribution. The modification of the ventilation activity of the Se-exposed groups, in comparison to this of reference groups (not exposed to Se) varied greatly according to the form and the concentrations of the Se used. Se concentrations in tissues indicated that selenite was the less bioavailable form whereas selenomethionine displayed the opposite trend. On the basis of this set of experiments, a limited number of conditions have been selected to provide highly contrasting ventilation flow rates and selenium bioaccumulation levels, in order to study the effects of long term exposures, i) at the molecular level, by measuring bio-markers of oxidative stress (forms of glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, and bio-marker of genotoxicity (comet assay), ii) at the (sub)cellular level by analysing Se micro-localisation in target organs and iii) at the individual level by monitoring the variation in the ventilatory flow

  13. Habitat creation and biodiversity maintenance in mangrove forests: teredinid bivalves as ecosystem engineers

    Directory of Open Access Journals (Sweden)

    Ian W. Hendy

    2014-09-01

    Full Text Available Substantial amounts of dead wood in the intertidal zone of mature mangrove forests are tunnelled by teredinid bivalves. When the tunnels are exposed, animals are able to use tunnels as refuges. In this study, the effect of teredinid tunnelling upon mangrove forest faunal diversity was investigated. Mangrove forests exposed to long emersion times had fewer teredinid tunnels in wood and wood not containing teredinid tunnels had very few species and abundance of animals. However, with a greater cross-sectional percentage surface area of teredinid tunnels, the numbers of species and abundance of animals was significantly higher. Temperatures within teredinid-attacked wood were significantly cooler compared with air temperatures, and animal abundance was greater in wood with cooler temperatures. Animals inside the tunnels within the wood may avoid desiccation by escaping the higher temperatures. Animals co-existing in teredinid tunnelled wood ranged from animals found in terrestrial ecosystems including centipedes, crickets and spiders, and animals found in subtidal marine ecosystems such as fish, octopods and polychaetes. There was also evidence of breeding within teredinid-attacked wood, as many juvenile individuals were found, and they may also benefit from the cooler wood temperatures. Teredinid tunnelled wood is a key low-tide refuge for cryptic animals, which would otherwise be exposed to fishes and birds, and higher external temperatures. This study provides evidence that teredinids are ecosystem engineers and also provides an example of a mechanism whereby mangrove forests support intertidal biodiversity and nurseries through the wood-boring activity of teredinids.

  14. Unionid bivalves (Mollusca: Bivalvia: Unionidae) of Presque Isle Bay, Erie, Pennsylvania

    Science.gov (United States)

    Masteller, E.C.; Maleski, K.R.; Schloesser, D.W.

    1993-01-01

    The purpose of this study was to determine species composition and relative abundance of unionid bivalves (Mollusca: Bivalvia: Unionidae) in Presque Isle Bay, Erie, Pennsylvania 1990-1992. This information was compared with data from the only other extensive survey of unionids in the bay conducted in 1909-1911 (Ortmann 1919) to assess changes over the 80 years preceding the present study. A total of 1,540 individuals representing 18 species were collected in 1990-1992. Five relatively common species (between 7 and 42% of total individuals), six uncommon species (2 and 6%), and seven rare species (<1%) were found. The rare species were Anodontoides ferussacianus, Lasmigona costata, Ligumia recta, Ptychobranchus fasciolaris, Quadrula pustulosa pustulosa, Strophitus undaulatus, and Truncilla donaciformis. Five of the species found in Presque Isle Bay (Leptodea fragilis, Ligumia nasuta, Potamilus alatus, Quadrula quadrula, and Truncilla donaciformis) are listed as critically imperiled and one species (Truncilla truncata) as extirpated in the State of Pennsylvania by the Western Pennsylvania Conservancy. Comparisons between unionid populations in 1909-1911 and 1990-1992 indicate few substantial changes occurred during the past 80 years. A total of 22 species were found; 21 in 1909-1911 and 18 in 1990-1992. Seventeen species were found in both studies, an additional four in 1909-1911 and one in 1990-1992. The relative abundance of 11 of the 17 species found in both studies remained stable (i.e., common or uncommon) over the past 80 years. Only four species listed as uncommon in 1909-1911 were listed as rare in 1990-1992. However, the invasion of the zebra mussel (Dreissena polymorpha) is considered a threat to the continued existence of the entire Unionidae fauna in Presque Isle Bay, a unique habitat of the Great Lakes.

  15. Haematopoiesis in molluscs: A review of haemocyte development and function in gastropods, cephalopods and bivalves.

    Science.gov (United States)

    Pila, E A; Sullivan, J T; Wu, X Z; Fang, J; Rudko, S P; Gordy, M A; Hanington, P C

    2016-05-01

    Haematopoiesis is a process that is responsible for generating sufficient numbers of blood cells in the circulation and in tissues. It is central to maintenance of homeostasis within an animal, and is critical for defense against infection. While haematopoiesis is common to all animals possessing a circulatory system, the specific mechanisms and ultimate products of haematopoietic events vary greatly. Our understanding of this process in non-vertebrate organisms is primarily derived from those species that serve as developmental and immunological models, with sparse investigations having been carried out in other organisms spanning the metazoa. As research into the regulation of immune and blood cell development advances, we have begun to gain insight into haematopoietic events in a wider array of animals, including the molluscs. What began in the early 1900's as observational studies on the morphological characteristics of circulating immune cells has now advanced to mechanistic investigations of the cytokines, growth factors, receptors, signalling pathways, and patterns of gene expression that regulate molluscan haemocyte development. Emerging is a picture of an incredible diversity of developmental processes and outcomes that parallels the biological diversity observed within the different classes of the phylum Mollusca. However, our understanding of haematopoiesis in molluscs stems primarily from the three most-studied classes, the Gastropoda, Cephalopoda and Bivalvia. While these represent perhaps the molluscs of greatest economic and medical importance, the fact that our information is limited to only 3 of the 9 extant classes in the phylum highlights the need for further investigation in this area. In this review, we summarize the existing literature that defines haematopoiesis and its products in gastropods, cephalopods and bivalves. PMID:26592965

  16. Jackknife-corrected parametric bootstrap estimates of growth rates in bivalve mollusks using nearest living relatives.

    Science.gov (United States)

    Dexter, Troy A; Kowalewski, Michał

    2013-12-01

    Quantitative estimates of growth rates can augment ecological and paleontological applications of body-size data. However, in contrast to body-size estimates, assessing growth rates is often time-consuming, expensive, or unattainable. Here we use an indirect approach, a jackknife-corrected parametric bootstrap, for efficient approximation of growth rates using nearest living relatives with known age-size relationships. The estimate is developed by (1) collecting a sample of published growth rates of closely related species, (2) calculating the average growth curve using those published age-size relationships, (3) resampling iteratively these empirically known growth curves to estimate the standard errors and confidence bands around the average growth curve, and (4) applying the resulting estimate of uncertainty to bracket age-size relationships of the species of interest. This approach was applied to three monophyletic families (Donacidae, Mactridae, and Semelidae) of mollusk bivalves, a group characterized by indeterministic shell growth, but widely used in ecological, paleontological, and geochemical research. The resulting indirect estimates were tested against two previously published geochemical studies and, in both cases, yielded highly congruent age estimates. In addition, a case study in applied fisheries was used to illustrate the potential of the proposed approach for augmenting aquaculture management practices. The resulting estimates of growth rates place body size data in a constrained temporal context and confidence intervals associated with resampling estimates allow for assessing the statistical uncertainty around derived temporal ranges. The indirect approach should allow for improved evaluation of diverse research questions, from sustainability of industrial shellfish harvesting to climatic interpretations of stable isotope proxies extracted from fossil skeletons. PMID:24071629

  17. Impact of high pCO2 on shell structure of the bivalve Cerastoderma edule.

    Science.gov (United States)

    Milano, Stefania; Schöne, Bernd R; Wang, Schunfeng; Müller, Werner E

    2016-08-01

    Raised atmospheric emissions of carbon dioxide (CO2) result in an increased ocean pCO2 level and decreased carbonate saturation state. Ocean acidification potentially represents a major threat to calcifying organisms, specifically mollusks. The present study focuses on the impact of elevated pCO2 on shell microstructural and mechanical properties of the bivalve Cerastoderma edule. The mollusks were collected from the Baltic Sea and kept in flow-through systems at six different pCO2 levels from 900 μatm (control) to 24,400 μatm. Extreme pCO2 levels were used to determine the effects of potential leaks from the carbon capture and sequestration sites where CO2 is stored in sub-seabed geological formations. Two approaches were combined to determine the effects of the acidified conditions: (1) Shell microstructures and dissolution damage were analyzed using scanning electron microscopy (SEM) and (2) shell hardness was tested using nanoindentation. Microstructures of specimens reared at different pCO2 levels do not show significant changes in their size and shape. Likewise, the increase of pCO2 does not affect shell hardness. However, dissolution of ontogenetically younger portions of the shell becomes more severe with the increase of pCO2. Irrespective of pCO2, strong negative correlations exist between microstructure size and shell mechanics. An additional sample from the North Sea revealed the same microstructural-mechanical interdependency as the shells from the Baltic Sea. Our findings suggest that the skeletal structure of C. edule is not intensely influenced by pCO2 variations. Furthermore, our study indicates that naturally occurring shell mechanical property depends on the shell architecture at μm-scale. PMID:27285613

  18. The effect of immersion time on burying depth of the bivalve Macoma balthica (Tellinidae)

    Science.gov (United States)

    de Goeij, Petra; Honkoop, Pieter J. C.

    2002-03-01

    As a characteristic buried tellinid bivalve, Macoma balthica has a long inhalent siphon that enables it to feed in two different ways: deposit and suspension feeding. To deposit feed efficiently on benthic microalgae, Macoma has to live close to the sediment surface, where it can graze an extensive surface area, but is within reach of many predators. Individuals that are more safely buried at a greater depth can only suspension feed, or deposit feed from a small surface area. We expected local differences in burying depth on intertidal mudflats to be caused by differences in immersion time (i.e. time available for feeding, particularly suspension feeding), since immersion time has been shown experimentally to affect body condition positively, and since body condition and burying depth in Macoma are postively related in the field. To test this we experimentally manipulated immersion time, and followed changes in burying depth and body condition. In the experiments, longer immersion time went consistently with greater burying depth of Macoma and higher body condition. On a transect in the western Wadden Sea, the deepest Macoma were indeed found at the intertidal level with the longest immersion time, but these were at that time not the animals with the highest body condition. Within each locality, however, body condition was positively correlated with burying depth. The experimental data and the within-locality data support the hypothesis that longer immersion time may influence burying depth through body condition. However, the fact that between-locality differences in burying depth seemed to be consistently related to immersion time, but not to body condition, indicates that body condition alone does not explain place-to-place variation in burying depth.

  19. Genetic connectivity between north and south Mid-Atlantic Ridge chemosynthetic bivalves and their symbionts.

    Directory of Open Access Journals (Sweden)

    Karina van der Heijden

    Full Text Available Transform faults are geological structures that interrupt the continuity of mid-ocean ridges and can act as dispersal barriers for hydrothermal vent organisms. In the equatorial Atlantic Ocean, it has been hypothesized that long transform faults impede gene flow between the northern and the southern Mid-Atlantic Ridge (MAR and disconnect a northern from a southern biogeographic province. To test if there is a barrier effect in the equatorial Atlantic, we examined phylogenetic relationships of chemosynthetic bivalves and their bacterial symbionts from the recently discovered southern MAR hydrothermal vents at 5°S and 9°S. We examined Bathymodiolus spp. mussels and Abyssogena southwardae clams using the mitochondrial cytochrome c oxidase subunit I (COI gene as a phylogenetic marker for the hosts and the bacterial 16S rRNA gene as a marker for the symbionts. Bathymodiolus spp. from the two southern sites were genetically divergent from the northern MAR species B. azoricus and B. puteoserpentis but all four host lineages form a monophyletic group indicating that they radiated after divergence from their northern Atlantic sister group, the B. boomerang species complex. This suggests dispersal of Bathymodiolus species from north to south across the equatorial belt. 16S rRNA genealogies of chemoautotrophic and methanotrophic symbionts of Bathymodiolus spp. were inconsistent and did not match the host COI genealogy indicating disconnected biogeography patterns. The vesicomyid clam Abyssogena southwardae from 5°S shared an identical COI haplotype with A. southwardae from the Logatchev vent field on the northern MAR and their symbionts shared identical 16S phylotypes, suggesting gene flow across the Equator. Our results indicate genetic connectivity between the northern and southern MAR and suggest that a strict dispersal barrier does not exist.

  20. Predation of intertidal infauna on juveniles of the bivalve Macoma balthica

    Science.gov (United States)

    Hiddink, J. G.; ter Hofstede, R.; Wolff, W. J.

    2002-03-01

    Juveniles of the bivalve Macoma balthica live on tidal flats in the Wadden Sea. This study examined the interaction of Macoma with the infaunal polychaetes Arenicola marina and Nereis diversicolor and the gastropod Retusa obtusa. The distribution of M. balthica spat on the flats, shortly after settlement in April, showed a positive correlation with the Arenicola distribution and a negative correlation with Nereis distribution. There were no locations where Macoma spat and Retusa occurred together. In August, Macoma spat had grown too large for predation by intertidal infauna. Small individuals of Macoma spat were found in stomachs of Arenicola (0.14 worm -1) and Nereis (0.05 worm -1). Laboratory experiments showed that Nereis and Retusa could reduce Macoma spat abundance, both in the absence and presence of sediment and alternative prey. Arenicola reduced the abundance of small Macoma (Nereis in 0.03 m 2 cages and examined the effect on Macoma density several weeks later. We found a significant negative relation between densities of polychaetes and Macoma spat for both polychaete species in these experimental plots. Peculiarly, we found a significant positive relation between manipulated Nereis density and adult Macoma density in the cages; we cannot explain this. Consumption rates, calculated both from stomach contents and from field experiments, were 45 to 102 Macoma m -2 d -1 for Arenicola and 5 to 116 Macoma m -2 d -1 for Nereis. These values are higher than recorded consumption rates by epibenthic predators in the same area. Nevertheless, between-year differences in year-class strength could not be explained by differential abundance of these polychaetes. In conclusion, Arenicola and Nereis had a negative effect on the abundance of Macoma <1.5 mm, which was at least partly caused by direct consumption. Retusa obtusa can eat juvenile Macoma, but probably did not so in the study area, because there were no locations where Retusa and Macoma spat occurred together

  1. Immunomodulation by different types of N-oxides in the hemocytes of the marine bivalve Mytilus galloprovincialis.

    Directory of Open Access Journals (Sweden)

    Caterina Ciacci

    Full Text Available The potential toxicity of engineered nanoparticles (NPs for humans and the environment represents an emerging issue. Since the aquatic environment represents the ultimate sink for NP deposition, the development of suitable assays is needed to evaluate the potential impact of NPs on aquatic biota. The immune system is a sensitive target for NPs, and conservation of innate immunity represents an useful basis for studying common biological responses to NPs. Suspension-feeding invertebrates, such as bivalves, are particularly at risk to NP exposure, since they have extremely developed systems for uptake of nano and microscale particles integral to intracellular digestion and cellular immunity. Evaluation of the effects of NPs on functional parameters of bivalve immunocytes, the hemocytes, may help understanding the major toxic mechanisms and modes of actions that could be relevant for different NP types in aquatic organisms.In this work, a battery of assays was applied to the hemocytes of the marine bivalve Mytilus galloprovincialis to compare the in vitro effects of different n-oxides (n-TiO(2, n-SiO(2, n-ZnO, n-CeO(2 chosen on the basis of their commercial and environmental relevance. Physico-chemical characterization of both primary particles and NP suspensions in artificial sea water-ASW was performed. Hemocyte lysosomal and mitochondrial parameters, oxyradical and nitric oxide production, phagocytic activity, as well as NP uptake, were evaluated. The results show that different n-oxides rapidly elicited differential responses hemocytes in relation to their chemical properties, concentration, behavior in sea water, and interactions with subcellular compartments. These represent the most extensive data so far available on the effects of NPs in the cells of aquatic organisms. The results indicate that Mytilus hemocytes can be utilized as a suitable model for screening the potential effects of NPs in the cells of aquatic invertebrates, and may

  2. Assessment of Bivalves as potential bioindicator of heavy metal pollution along Ghana's coast using Instrumental Neutron Activation Analysis

    International Nuclear Information System (INIS)

    The assessment of environmental metal pollution along the coast of Ghana was investigated by analysing the heavy and trace metals in the soft body tissue and shells of two abundant bivalve molluses Donax pulchelus, the brown mussel Perna perna and the sediment in which they live at three different sampling locations (Accra, Cape Coast and Axim). Potentially toxic or toxic metals analysed in this study were Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Sc, V, Zn using the analytical technique instrumental Neutron Activation Analysis (INAA) in the quantitative determination of the heavy metals. Marine sediment reference material (Estuarine Sediment SRM 1646a) and Peach leaves SRM 1547 provided the certified reference in the quality assurance control. The concentration found in the potentially toxic heavy metals (As, Cd, Co, Cu, Hg, Ni,and Zn) all recorded lower than the maximum acceptable limits in the bivalve molluscs designated for human consumption, fluctuating between blow detection limit <0.03 to 180.38μ/g. The other elements (Al, Ca, Fe, K, Mg, Mn and Na) recorded a high concentration in both Donax pulchelus and Perna perna (4.54μ/g to 565.13μ/g) in all the sampling location.The minor elements (V and Sc) recorded between 0.05 μ/g to 5.68μ/g. The data on the concentration of the bivalve mollusc also showed lower values compared with other regions of the world. The physicochemical parameters determined were generally supportive of aquatic life providing the necessary conditions. (au)

  3. Study on the bioaccumulation of Polonium-210 on bivalve indicator organisms of Tamilnadu and Pondicherry coast (East Coast of India)

    International Nuclear Information System (INIS)

    210Po is a major contributor (90%) of the natural radiation dose from alpha-emitting radionuclides, received by most marine organisms. Among marine organisms, benthic fauna are superior to many other biological groups, since they could be monitored due to their sedentary habits and then must either adapt to environmental stress or perish. They also reflect the water conditions not only at the time of sampling but also for some past time as well. The affinity of 210Po for protein enables it to pass through the food chain, and increased body burdens of 210Po have been found where diets include protein-rich meat and seafood. The present study was launched to evaluate the rate of accumulation of 210Po in the benthic bivalve molluscs such as Perna indica, P.viridis, Meretrix casta, Cardium coronatum, Gafrarium tumidum, Paphia textrix, Vellorita cyprinodea and Pinctada sp., of Tamilnadu and Pondicherry coast. Water samples, sediments and bivalves were collected from Gulf of Mannar (6 sampling stations), Palk Strait (8 sampling stations) of Tamilnadu and Pondicherry (6 sampling stations). 210Po determination as made was as per standard protocols. The results showed that 210Po concentration in coastal waters of Gulf of Mannar, Palk Strait and Pondicherry ranged 0.5 - 2.83 mBq/l (mean 1.33 mBq/I), 2.14 - 32.14 mBq/l (mean 15.3 mBq/l) and 1.36 - 2.0 mBq/1 (mean 1.59 mBq/1) respectively. The sediments maintained higher level of 210Po (mean value of 3.62 Bq/kg in Gulf of Mannar, 107.9 Bq/kg in Palk Strait and 3.0 Bq/kg in Pondicherry) than water. The 210Po rich sediment therefore serves as a vital link in the transfer of Polonium from water to the marine organisms. The concentration of 210Po in eight species of bivalves collected from the study area, recorded a maximum level ranging from 65.2 to 2668.9 Bq/kg in soft tissues and from 1.19 to 15.3 Bq/kg in shells. The bioaccumulation ability in bivalve species with reference to 210Po was observed to be highly variable among the

  4. Assimilation efficiencies and turnover rates of trace elements in marine bivalves: A comparison of oysters, clams and mussels

    Science.gov (United States)

    Reinfelder, J.R.; Wang, W.-X.; Luoma, S. N.; Fisher, N.S.

    1997-01-01

    Assimilation efficiencies (AEs) and physiological turnover-rate constants (k) of six trace elements (Ag, Am, Cd, Co, Se, Zn) in four marine bivalves (Crassostrea virginica Gmelin,Macoma balthica Linnaeus, Mercenaria mercenaria Linnaeus, and Mytilus edulis Linnaeus) were measured in radiotracer-depuration experiments. Egestion rates of unassimilated elements were highest during the first 24 h of depuration and declined thereafter. Significant egestion of unassimilated Co, however, continued for up to 5 d in Macoma balthica,Mercenaria mercenaria and Mytilus edulis. With the exception of the extremely low values for110 mAg, 109Cd, and 65Zn in C. virginica, physiological turnover-rate constants (k) showed no general pattern of variation among elements, bivalve species or food types, and were relatively invariant. Values from  ≤0.001 to 0.1 d−1 were observed, but excluding those for Co, most values were  ≤0.04 d−1. In all four species, the AEs of Ag, Am, and Co were generally lower than those of Cd, Se, and Zn. The AEs of Ag, Cd, Se, and Zn in these bivalves are directly related to the proportion of each element in the cytoplasmic fraction of ingested phytoplankton, indicating that >80% of elements in a prey alga's cytoplasm was assimilated. C. virginica, Macoma balthica, and Mercenaria mercenaria assimilated ∼36% of the Ag and Cd associated with the non-cytoplasmic (membrane/organelle) fraction of ingested cells in addition to the cytoplasmic fraction. The ratio of AE:k, which is proportional to the consumer–prey trace-element bioaccumulation factor (concentration in consumer:concentration in prey) was generally greater for Cd, Se, and Zn than for Ag, Am, and Co. This ratio was lowest in Mytilus edulis, suggesting that this bivalve, the most widely employed organism in global biomonitoring, is relatively inefficient at accumulating important elements such as Ag, Cd, and Zn from ingested phytoplankton.

  5. Neurologic Manifestations of Childhood Rheumatic Diseases

    Directory of Open Access Journals (Sweden)

    Reza SHIARI

    2013-01-01

    Full Text Available How to Cite this Article: Shiari R. Neurologic Manifestations of Childhood Rheumatic Diseases.  Iran J Child Neurol Autumn 2012; 6(4: 1-7.Children with rheumatic disorders may have a wide variety of clinical features ranging from fever or a simple arthritis to complex multisystem autoimmune diseases. Information about the prevalence of neurological manifestations in children with rheumatologic disorders is limited. This review describes the neurologic complications of childhood Rheumatic disease either solely or combined with symptoms of other organs involvement, as a primary manifestation or as a part of other symptoms, additionally. References1. Benseler S, Schneider R. Central nervous system vasculitisin children. Curr Opin Rheumatol. 2004 Jan;16(1:43-50. 2. Benseler SM. Central nervous system vasculitis in children. Curr Rheumatol Rep. 2006 Dec;8(6:442-9. 3. Mc Carthy HJ, Tizard EJ. Clinical practice: Diagnosis and management of Henoch-Schönlein purpura. Eur J Pediatr.2010 Jun;169(6:643-50. Epub 2009 Dec 12. 4. Robson WL, Leung AK. Henoch-Schönlein purpura. AdvPediatr. 1994;41:163-94. 5. Ostergaard JR, Storm K, Neurologic manifestations of Schönlein-Henoch purpura. Acta Paediatr Scand. 1991Mar;80(3:339-42. 6. Bakkaloğlu SA, Ekim M, Tümer N, Deda G, ErdenI, Erdem T. Cerebral vasculitis in Henoch-Schönlein purpura. Nephrol. Dial Transplant. 2000 Feb;15(2:246-8. 7. Mattoo TK, al-Mutair A, al-Khatib Y, Ali A, al-SohaibaniMO. Group A beta-haemolytic streptococcal infection and Henoch-Schonlein purpura with cardiac, renal and neurological complications. Ann Trop Pediatr. 1997Dec;17(4:381-6. 8. Ha TS, Cha SH. Cerebral vasculitis in Henoch-Schönlein purpura: a case with sequential magnetic resonance imaging. Pediatr Nephrol. 1996;10:634-6. 9. Saket S, Mojtahedzadeh S, Karimi A, Shiari R, ShirvaniF. Relationship between electrolyte abnormalities, ESR,CRP and platelet count with severity of Kawasaki disease.Yafteh. 2009;11(3:5-14. 10

  6. Oral mucosal manifestations of autoimmune skin diseases.

    Science.gov (United States)

    Mustafa, Mayson B; Porter, Stephen R; Smoller, Bruce R; Sitaru, Cassian

    2015-10-01

    A group of autoimmune diseases is characterised by autoantibodies against epithelial adhesion structures and/or tissue-tropic lymphocytes driving inflammatory processes resulting in specific pathology at the mucosal surfaces and the skin. The most frequent site of mucosal involvement in autoimmune diseases is the oral cavity. Broadly, these diseases include conditions affecting the cell-cell adhesion causing intra-epithelial blistering and those where autoantibodies or infiltration lymphocytes cause a loss of cell-matrix adhesion or interface inflammation. Clinically, patients present with blistering, erosions and ulcers that may affect the skin as well as further mucosal surfaces of the eyes, nose and genitalia. While the autoimmune disease may be suspected based on clinical manifestations, demonstration of tissue-bound and circulating autoantibodies, or lymphocytic infiltrates, by various methods including histological examination, direct and indirect immunofluorescence microscopy, immunoblotting and quantitative immunoassay is a prerequisite for definitive diagnosis. Given the frequency of oral involvement and the fact that oral mucosa is the initially affected site in many cases, the informed practitioner should be well acquainted with diagnostic and therapeutic aspects of autoimmune dermatosis with oral involvement. This paper reviews the pathogenesis and clinical presentation of these conditions in the oral cavity with a specific emphasis on their differential diagnosis and current management approaches. PMID:26117595

  7. DENGUE WITH ATYPICAL MANIFESTATIONS AND WHO CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    Jayant Mahadeorao

    2015-09-01

    Full Text Available Dengue fever and dengue haemorrhagic fever are important arboviral diseases. Dengue virus belongs to family Flaviviridae , has four serotypes that spread by the bite of infected Aedes mosquitoes . Dengue epidemics can have a significant economic and health t oll. Worldwide, an estimated 3.6 billion people are at risk of infection with about 50 - 100 million new cases each year Illness produced by any of the four dengue virus serotypes varies from mild asymptomatic illness to severe fatal dengue haemorrhagic fe ver/dengue shock syndrome (DHF/DSS. During the early febrile stage clinicians cannot predict which patients will progress to severe disease. Atypical manifestations were reported are associated with high risk of mortality. The existing WHO dengue classific ation scheme and case definitions have some drawbacks. A global strategy to reduce the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently un der development could also make an important contribution to dengue control in the future

  8. Neurological manifestations of dengue viral infection

    Directory of Open Access Journals (Sweden)

    Carod-Artal FJ

    2014-10-01

    Full Text Available Francisco Javier Carod-Artal1,21Neurology Department, Raigmore hospital, Inverness, UK; 2Universitat Internacional de Catalunya (UIC, Barcelona, Spain Abstract: Dengue is the most common mosquito-borne viral infection worldwide. There is increased evidence for dengue virus neurotropism, and neurological manifestations could make part of the clinical picture of dengue virus infection in at least 0.5%–7.4% of symptomatic cases. Neurological complications have been classified into dengue virus encephalopathy, dengue virus encephalitis, immune-mediated syndromes (acute disseminated encephalomyelitis, myelitis, Guillain–Barré syndrome, neuritis brachialis, acute cerebellitis, and others, neuromuscular complications (hypokalemic paralysis, transient benign muscle dysfunction and myositis, and dengue-associated stroke. Common neuro-ophthalmic complications are maculopathy and retinal vasculopathy. Pathogenic mechanisms include systemic complications and metabolic disturbances resulting in encephalopathy, direct effect of the virus provoking encephalitis, and postinfectious immune mechanisms causing immune-mediated syndromes. Dengue viruses should be considered as a cause of neurological disorders in endemic regions. Standardized case definitions for specific neurological complications are still needed. Keywords: encephalitis, encephalopathy, dengue fever, neurological complications

  9. Radiation nephritis. Clinical manifestations and pathophysiologic mechanisms

    International Nuclear Information System (INIS)

    Radiation nephritis is both volume and dose related. Clinical experience would indicate that a minimum of one third of the renal volume needs to be excluded from nephrotoxic doses which appears to have a threshold of 2,000 cGy. The site of damage leading to renal failure appears to be the microvasculature ultimately expressed as glomerulosclerosis. How much direct damage to the tubular system contributes to this process is unclear, but undoubtedly the resultant systemic physiologic effects potentiate the expression of damage in the irradiated kidney. The acute syndrome, with all the potential manifestations of renal failure, rarely presents sooner than six months and appears to have no clear prodrome, although it would seem reasonable that a subclinical syndrome consisting of abnormalities detectable by urinalysis may occur. Treatment of radiation-induced nephritis or hypertension is no different from treatment for nephritis from any other cause and should be aggressive with lifelong follow-up. Carcinogenesis is a rare late expression of radiation-induced kidney damage. 25 references

  10. Subperiosteal osteoid osteoma: radiographic and pathologic manifestations

    International Nuclear Information System (INIS)

    Objective.To demonstrate the radiologic and pathologic manifestations of osteoid osteoma arising beneath the periosteum, on the surface of the bone. Design. One hundred and sixty osteoid osteomas were seen over a 30-year period. The radiologic, pathologic and operative findings of those that were subperiosteal were reviewed. Patients. Eleven patients with subperiosteal osteoid osteoma were reviewed. The patients ranged in age from 13 to 36 years with a mean of 24 years. Eight were male and three were female. Results and conclusion. Eleven subperiosteal lesions were studied. The reactive periostitis of four lesions was atypical and misleading. Four lesions had features similar to the more common intracortical variety. Three lesions occurring within the joint like other intra-articular lesions were barely seen on plain radiographs. Bone scan and CT scan were virtually diagnostic. The histopathology of these lesions was also atypical though not misleading. In conclusion, subperiosteal osteoid osteoma is a rare lesion with atypical radiographic and histopathologic features. The unusual reactive periostitis seen in several extra-articular cases may suggest other diagnoses. (orig.). With 4 figs., 2 tabs

  11. Subperiosteal osteoid osteoma: radiographic and pathologic manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Shankman, S. [Department of Radiology, Hospital for Joint Diseases/OI, 301 East 17th Street, New York, NY 10003 (United States); Desai, P. [Department of Pathology, Hospital for Joint Diseases/OI, 301 East 17th Street, New York, NY 10003 (United States); Beltran, J. [Department of Radiology, Hospital for Joint Diseases/OI, 301 East 17th Street, New York, NY 10003 (United States)

    1997-08-01

    Objective.To demonstrate the radiologic and pathologic manifestations of osteoid osteoma arising beneath the periosteum, on the surface of the bone. Design. One hundred and sixty osteoid osteomas were seen over a 30-year period. The radiologic, pathologic and operative findings of those that were subperiosteal were reviewed. Patients. Eleven patients with subperiosteal osteoid osteoma were reviewed. The patients ranged in age from 13 to 36 years with a mean of 24 years. Eight were male and three were female. Results and conclusion. Eleven subperiosteal lesions were studied. The reactive periostitis of four lesions was atypical and misleading. Four lesions had features similar to the more common intracortical variety. Three lesions occurring within the joint like other intra-articular lesions were barely seen on plain radiographs. Bone scan and CT scan were virtually diagnostic. The histopathology of these lesions was also atypical though not misleading. In conclusion, subperiosteal osteoid osteoma is a rare lesion with atypical radiographic and histopathologic features. The unusual reactive periostitis seen in several extra-articular cases may suggest other diagnoses. (orig.). With 4 figs., 2 tabs.

  12. Extraintestinal Manifestations of Inflammatory Bowel Disease.

    Science.gov (United States)

    Vavricka, Stephan R; Schoepfer, Alain; Scharl, Michael; Lakatos, Peter L; Navarini, Alexander; Rogler, Gerhard

    2015-08-01

    Extraintestinal manifestations (EIM) in inflammatory bowel disease (IBD) are frequent and may occur before or after IBD diagnosis. EIM may impact the quality of life for patients with IBD significantly requiring specific treatment depending on the affected organ(s). They most frequently affect joints, skin, or eyes, but can also less frequently involve other organs such as liver, lungs, or pancreas. Certain EIM, such as peripheral arthritis, oral aphthous ulcers, episcleritis, or erythema nodosum, are frequently associated with active intestinal inflammation and usually improve by treatment of the intestinal activity. Other EIM, such as uveitis or ankylosing spondylitis, usually occur independent of intestinal inflammatory activity. For other not so rare EIM, such as pyoderma gangrenosum and primary sclerosing cholangitis, the association with the activity of the underlying IBD is unclear. Successful therapy of EIM is essential for improving quality of life of patients with IBD. Besides other options, tumor necrosis factor antibody therapy is an important therapy for EIM in patients with IBD. PMID:26154136

  13. Neuro-ophthalmic manifestations of prematurity

    Directory of Open Access Journals (Sweden)

    Preeti Patil Chhablani

    2014-01-01

    Full Text Available Increasing rates of preterm births coupled with better survival of these infants have resulted in higher prevalence of systemic and ocular complications associated with prematurity. In addition to retinopathy of prematurity, infants who are born preterm may suffer from severe visual impairment as a result of hypoxic ischemic encephalopathy, hypoglycemia, and other metabolic imbalances. The effect of these processes on the anterior visual pathway may result in optic atrophy, optic nerve hypoplasia or optic disc cupping and affection of the posterior visual pathway leads to cortical visual impairment (CVI. Other ocular associations include strabismus, nystagmus, and ocular motor abnormalities such as tonic down gaze and defective saccades and pursuits. Cortical and subcortical involvement also manifests as defects in functional vision and these have not yet been completely understood. Children with CVI may have visual field defects, photophobia, defective visual processing, and deficient color vision. Since most of these children also suffer from additional systemic disabilities, evaluation, and management remains a challenge. However, early diagnosis and initiation of rehabilitation therapy can prove to be of significant benefit in these children.

  14. Clinical manifestations and pathophysiology of lissencephaly

    International Nuclear Information System (INIS)

    Four cases of lissencephaly were analyzed in light of clinical manifestations, CT findings and the state of hydrocephalus. Lissencephaly had been diagnosed mainly by autopsy until CT scan was introduced in the early 1970's. Since then, diagnosis of lissencephaly early in life is possible. Presently the major interest in this congenital CNS anomaly, which is caused by a neuronal migration disorder in the relatively late stages of fetal development, is to learn the dynamic pathophysiological state and management. The purpose of this paper is to analyze those points of lissencephaly in diagnosis during life and possible treatment in the hydrocephalic state. The common findings in CT in all four cases are as follows: No. 1. smooth cortical surface (agyria--pachygyria), No. 2. wide sylvian fissure (complete or incomplete lack of opercularization, No. 3. ventricular dilatation (remarkable bilateral enlargement of lateral ventricle and third ventricle--colpocephaly), No. 4. wide subdural or subarachnoid space in supratentorial region, No. 5. periventricular low density, No. 6. midline cavum, No. 7. normal CT findings in posterior fossa structure. Three out of four patients demonstrated full or bulged and tense anterior fontanella. Because of this suggestion of increased intracranial pressure and enlarged ventricles with periventricular lucency in CT findings, one patient underwent CT cisternography for dynamic analysis of the CSF circulation and continuous ICP monitoring for dynamic evaluation of the ICP pattern. The results revealed very much delayed CSF circulation and intermittently increased. ICP, with pressure waves appearing in 35.7 % of all recordings. (J.P.N.)

  15. A Clinico- Epidemiological Study Of Filarial Related Orthopaedic Manifestations

    Directory of Open Access Journals (Sweden)

    Patond K.R

    1992-01-01

    Full Text Available An epidemiological study was undertaken to study the incidence and distribution of orthopaedic manifestations of filariasis in an endemic area. A total of 207 cases were clinically examined and investigated. Patients were divided into three groups , viz., Group A: Orthopaedic manifestations with no history of filariasis . Group B: Orthopaedic manifestations with history of filariasis such as microfilaraemia or filarial fevers etc., Group C: Orthopaedic manifestations with chronic manifestations such as elephantiasis, hydrocele etc. To confirm filarial etiology, all the cases were examined for the presence of filarial antibody by indirect ELISA using wuchereda bancrofti microfilarial excretory- secretary antigen (wd Mf ESAg . A total of 61 of 102 patients of Group A, 14 of 21 patients of group B, and 73 of 84 patients of Group C were positive for filarial antibody. This study showed the prevalence of filarial antibody in about 71.4% of various orthopaedic manifestations.

  16. Late Devonian (Frasnian) bivalves from the Nocedo Formation: the results of Wilhelm Kegel’s 1927 field trip to northern Spain

    OpenAIRE

    Amler, M.R.W.

    2010-01-01

    During a field trip to the Peña-Corada Unit of the southernmost Esla region of the Cantabrian Mountains in 1927, the German stratigrapher Wilhelm Kegel sampled brachiopods and bivalves from a section in the Laoz valley near La Ercina. The stratigraphic position is believed to be part of the Nocedo Formation of Frasnian age. This fauna includes poorly preserved steinkerns of a near-shore bivalve fauna that was prepared for publication including labels and proposed names, but never published. T...

  17. Implementação da norma NP EN ISO 22000:2005 em centros de depuração de bivalves: estudo de caso

    OpenAIRE

    Jesus, Luci Catarina Agostinho

    2016-01-01

    Dissertação de Mestrado, Tecnologia dos Alimentos, Instituto Superior de Engenharia, Universidade do Algarve, 2016 Os bivalves, são importantes em termos socio-económicos e na gastronomia portuguesa, e são abundantes na Ria Formosa e costa Algarvia adjacente. De entre os bivalves, a amêijoa-boa (Ruditapes decussatus) é uma espécie com elevado interesse económico que é muito consumida pelo mundo fora, mas particularmente nos países do sul da Europa. Considerando as condições amb...

  18. Onset Manifestations of Spinal and Bulbar Muscular Atrophy (Kennedy's Disease).

    Science.gov (United States)

    Finsterer, Josef; Soraru, Gianni

    2016-03-01

    Spinal and bulbar muscular atrophy (SBMA) is regarded as a disorder with adult onset between third and fifth decade of life. However, there is increasing evidence that SBMA may start already before adulthood. The present study investigated the following: (1) Which clinical manifestations have been described so far in the literature as initial manifestations? (2) Which was the age at onset of these manifestations? and (3) Is age at onset dependent on the CAG-repeat length if non-motor manifestations are additionally considered? Data for this review were identified by searches of MEDLINE using appropriate search terms. Onset manifestations in SBMA can be classified as frequent, rare, motor, non-motor, or questionable. Frequent are muscle weakness, cramps, fasciculations/twitching, tremor, dysarthria, dysphagia, or gynecomastia. Rare are myalgia, easy fatigability, exercise intolerance, polyneuropathy, hyper-CKemia, under-masculinized genitalia, scrotal hypospadias, microphallus, laryngospasm, or oligospermia. Questionable manifestations include sensory disturbances, cognitive impairment, increased pituitary volume, diabetes, reduced tongue pressure, elevated creatine-kinase, or low androgens/high estrogens. Age at onset is highly variable ranging from 4-76 years. Non-motor manifestations develop usually before motor manifestations. Age at onset depends on what is considered as an onset manifestation. Considering non-motor onset manifestations, age at onset is independent of the CAG-repeat size. In conclusion, age at onset of SBMA depends on what is regarded as onset manifestation. If non-motor manifestations are additionally considered, age at onset is independent of the CAG-repeat length. Since life expectancy is hardly reduced in SBMA, re-investigation of patients from published studies with regard to their initial disease profiles is recommended. PMID:26482145

  19. 19 CFR 123.22 - In-transit manifest.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false In-transit manifest. 123.22 Section 123.22 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or Mexico § 123.22 In-transit manifest. (a) Manifest required....

  20. Various clinical manifestations of brucellosis infection

    Directory of Open Access Journals (Sweden)

    Turkulov Vesna

    2008-01-01

    Full Text Available Introduction. Brucellosis is an acute, subacute or chronical disease, from the zoonosis group, caused by various types of bacteria belonging to genus Brucellae. It is transmitted to humans from domestic animals: goats, sheep, cattle, pigs and dogs. The course of the disease may either be asymptomatic, or produce a variety of clinical manifestations, ranging from light ones to extremely severe clinical forms. The aim of the study was to follow the clinical features of brucella infection in the hospital-treated patients, as well as its course and outcome. Material and Methods. The investigation included 15 patients, treated for brucella infection at the Clinic for infectious diseases during the last two years (2004 and 2005. Results. All patients were adults, their age ranged from 18 to 71, 49.96 on average. The epidemiological questionnaire was positive in all patients, confirming contacts with the ailing animals, or consumption of cheese made from milk of diseased animals. They all exhibited the classic symptoms - increased body temperature and shiver, fever, sweating, malaise and headache, the so called flu like state. The serum agglutination test was positive in respect to brucellosis, the titre ranged from 1:80 to 1:1280. Eight patients suffered excessive back pain, accompanied with impeded walk. In half of them magnetic resonance imaging confirmed the spondylodiscitis diagnosis. Three patients had clinical features of knee arthritis, two had bronchopneumonia, one pancreatitis, and one developed the signs of an acute kidney insufficiency. The outcome was favorable in all patients - They recuperated or healed completely. In one patient a relapse occurred, leading to the chronic course of the illness. Discussion. Although predominantly Mediterranean Brucellosis is a worldwide spread disease. During the last two years, an increased incidence of the disease has been observed. Conclusion. Due to the variety of clinical futures and the possibility

  1. Audiovestibular manifestations in patients with ankylosing spondylitis.

    Science.gov (United States)

    Amor-Dorado, Juan C; Barreira-Fernandez, Maria P; Vazquez-Rodriguez, Tomas R; Gomez-Acebo, Ines; Miranda-Filloy, Jose A; Diaz de Teran, Teresa; Llorca, Javier; Gonzalez-Gay, Miguel A

    2011-03-01

    Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown origin affecting up to 1% of the population. Little is known about audiovestibular impairment in patients with AS, especially the presence of cochleovestibular dysfunction in these patients. To investigate audiovestibular manifestations in AS, we studied a series of 50 consecutive patients who fulfilled the modified New York diagnostic criteria for AS and 44 matched controls. Individuals with history of cardiovascular disease, cerebrovascular complications, peripheral artery disease, renal insufficiency, syphilis, Meniere and other vestibular syndromes, infections involving the inner ear, barotrauma, or in treatment with ototoxic drugs were excluded. Most patients with AS were men (80%). The mean age at the time of study was 52.5 years, and mean age at the onset of symptoms was 34.4 years. Twenty-nine (58%) patients showed abnormal hearing loss in the audiogram compared to only 8 (18%) controls (p < 0.001). Values of audiometric tests (pure-tone average and speech reception threshold) yielded significant differences between patients and controls (p < 0.001). It is noteworthy that the audiogram shape disclosed a predominant pattern of high-frequency sensorineural hearing loss in AS patients (50%) compared to controls (18%) (p = 0.002). Also, AS patients exhibited abnormal vestibular tests more commonly than controls. AS patients had an increased frequency of head-shaking nystagmus (20%) compared to controls (0%) (p < 0.001). Moreover, patients (26%) showed a significantly increased frequency of abnormal caloric test compared to controls (0%) (p < 0.001). Finally, a significantly increased frequency of abnormal clinical test of sensory integration and balance with a predominant vestibular loss pattern was observed in patients (36%) compared to controls (5%) (p < 0.001). In conclusion, the current study demonstrates strong evidence for inner ear compromise in patients with AS. PMID:21358443

  2. Joint use of multiple Synthetic Aperture Radar imagery for the detection of bivalve beds and morphological changes on intertidal flats

    Science.gov (United States)

    Gade, Martin; Melchionna, Sabrina

    2016-03-01

    We analyzed a large amount of high-resolution Synthetic Aperture Radar (SAR) data of dry-fallen intertidal flats on the German North Sea coast with respect to the imaging of sediments, macrophytes, and mussels. TerraSAR-X and Radarsat-2 images of four test areas acquired from 2008 to 2013 form the basis for the present investigation and are used to demonstrate that pairs of SAR images, if combined through basic algebraic operations, can already provide indicators for morphological changes and for bivalve (oyster and mussel) beds. Multi-temporal analyses of series of SAR images allow detecting bivalve beds, since the radar backscattering from those beds is generally high, whereas that from sediments may vary with imaging geometry and environmental conditions. Our results further show evidence that also single-acquisition, dual-polarization SAR imagery can be used in this respect. The polarization coefficient (i.e., the ratio of the difference and the sum of both co-polarizations) can be used to infer indicators for oyster and blue-mussel beds.

  3. Composition and distribution of bivalves of the abyssal plain adjacent to the Kuril-Kamchatka Trench (Pacific Ocean)

    Science.gov (United States)

    Kamenev, Gennady M.

    2015-01-01

    The KuramBio German-Russian deep-sea expedition ("Sonne", 2012) revealed a rich fauna of bivalves (55 species belonging to 21 families) on the abyssal plain (4861-5787 m) adjacent to the Kuril-Kamchatka Trench. Per station species richness varied from 18 to 33 species. The richest families were Cuspidariidae (7 species), Tindariidae (6 species), Thyasiridae (6 species), and Xylophagidae (5 species). The families Nuculidae, Malletidae, Yoldiidae, Mytilidae, Protocuspidariidae, and Verticordiidae were represented by a single species. Representatives of the family Siliculidae were recorded in the northwestern Pacific for the first time. Thirteen species (23.6%) were most common in the investigated northwestern Pacific region. Nine species (16.4%) were only found at one of the stations. Eight species (14.5%) are first records for the northwestern Pacific, of which Yoldiella cf. jeffreysi (Hidalgo, 1877), Pristigloma cf. albaSanders and Allen, 1973, and Syssitomya cf. pourtalesianaOliver, 2012 were previously known only for the Atlantic Ocean. The high diversity and richness of the bivalve fauna on the abyssal plain in the Kuril-Kamchatka Trench area may be connected to the favorable feeding conditions in this, one of the most highly productive areas of the Pacific Ocean.

  4. Identification of PAHs sources in the intertidal bivalves and subtidal sediments following the Sea Prince oil spill in Korea

    International Nuclear Information System (INIS)

    5,040 tons of crude oil was spilled into the marine environment when the Sea Prince oil tanker ran aground on July 23, 1995 near the South Coast of Korea at Sori Island. The environmental impact of this accidental spill has been monitored since 1996 to assess the spatial distribution and effects of spilled oil on the marine environment. This paper examined the residual effects of beached oil. The transport of dispersed oil into the subtidal area was also investigated. A total of 24 polycyclic aromatic hydrocarbon (PAH) samples were analyzed. Principal component analysis was also conducted to identify the status of weathering and to determine pollution sources and a pattern of bioaccumulation. Oil-derived PAHs were found in bivalves of Kumo Island and Soheongan Island. All bivalves showed similar patterns in the first half of 2000, but seasonal variations changed this to the point that there was no major evidence of transport of oil-derived PAHs into the subtidal environment. One station still showed very high concentration, suggesting the limited input of particle-bound PAHs into the confined area. The subtidal sediment group was dominated by high molecular weight PAHs, implying combustion-derived sources. 18 refs., 3 tabs., 7 figs

  5. Uptake and loss of 134Cs and 60Co by the Baltic bivalve Macoma Baltica under laboratory conditions

    International Nuclear Information System (INIS)

    In order to predict the radiological impact on man via harvestable sea food products, it is essential to make a critical evaluation of the transfer routes and the rates on which radionuclides are transferred through the aquatic food chains. In the Baltic, the bivalve Macoma Baltica comprises a main food item for fish species of commercial interest, such as flounder. The accumulation and release of Cs-134 and Co-60 by Macoma was experimentally investigated. The nuclides were added to the water and the activity content of the bivalves was determined at regular intervals. The uptake was quite rapid, 40 per cent (Cs) and 55 per cent (Co) respectively of the final steady state was obtained after 24 hours. The subsequent release was rapid as well, 50 per cent (Cs) and 40 per cent (Co) respectively of the accumulated activity was lost within 6 days. The experiments demonstrated that the major intake route following short-term releases of activity will be from the water column. The close connection between activity in water and organism can thus be used for predictive purposes without the complication of radionuclide uptake from contaminated sediments. (Author)

  6. Effects of ocean acidification on the metabolic rates of three species of bivalve from southern coast of China

    Institute of Scientific and Technical Information of China (English)

    LIU Wenguang; HE Maoxian

    2012-01-01

    Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH,a process known as “ocean acidification”.The pearl oyster Pinctada fucata,the noble scallop Chlamys nobilis,and the green-lipped mussel Perna viridis are species of economic and ecological importance along the southern coast of China.We evaluated the effects of seawater acidification on clearance,respiration,and excretion rates in these three species.The animals were reared in seawater at pH 8.1 (control),7.7,or 7.4.The clearance rate was highest at pH 7.7 for P.fucata and at pH 8.1 for C.nobilis and P.viridis.The pH had little effect on the respiration rate of P.fucata and P.viridis.In contrast,the respiration rate was significantly lower at pH 7.4 in C.nobilis.The excretion rate was significantly lower at pH 7.4 than pH 8.1 for all species.The results indicate that the reduction in seawater pH likely affected the metabolic process (food intake,oxygen consumption,and ammonia excretion) of these bivalves.Different species respond differently to seawater acidification.Further studies are needed to demonstrate the exact mechanisms for this effect and evaluate adaptability of these bivalves to future acidified oceans.

  7. Effect of cage design on growth of transplanted Asian clams: implications for assessing bivalve responses in streams.

    Science.gov (United States)

    Hull, Matthew S; Cherry, Donald S; Merricks, Timothy C

    2004-01-01

    This study was designed to determine whether survivorship and growth of Asian clams (Corbicula fluminea [Müller]) differed significantly between two types of field enclosures. Enclosures were either flexible mesh bags or rigid cages (hereto after referred as bioboxes) designed to homogenize substrate among study sites and accommodate Asian clam feeding mechanisms. For 96d, cages remained at 12 Clinch River (CR), Hurricane Fork (HF), and Dump's Creek (DC) sites upstream and downstream of a coal-fired power plant discharge, coal mining effluent, and coal combustion-related disposal facilities in Carbo, Virginia. Although survivorship was not significantly different between cage types, mean growth of clams in bioboxes was significantly greater overall (p = 0.0157). Despite the difference in growth between the two cage types, both confirmed significant reductions of survivorship and growth directly below the power plant discharge. Additionally, coefficient of variance values for biobox growth data were reduced at most study sites (averages of 16% for bioboxes versus 19% for mesh bags). Our results have implications toward strengthening weight-of-evidence approaches used to link impairment of transplanted bivalves to environmental contaminants. More importantly, these results suggest that ecotoxicological impairment of bivalves transplanted downstream of the coal-fired power plant discharge functioned independently of site-specific substrate provisions. PMID:15327146

  8. Gal/GalNAc specific multiple lectins in marine bivalve Anadara granosa.

    Science.gov (United States)

    Adhya, Mausumi; Singha, Biswajit

    2016-03-01

    Complete lectin mapping of molluscs with their diversified recognition pattern and possible role in lectin-carbohydrate interaction based immune response triggering need much attention. In this communication, Gal/GalNAc specific three lectins AGL-IA (Anadara granosa lectin-IA), AGL-IB (A. granosa lectin-IB) and AGL-IV (A. granosa lectin-IV) and a lectin having hemolytic activity AGL-III (A. granosa lectin-III) were purified from the plasma of A. granosa bivalve by a combination of gel filtration and affinity chromatography. AGL-IA and IB were oligomeric lectins whereas, AGL-III and IV were monomeric. The molecular weight of AGL-IA, IB, III and IV were 375, 260, 45 and 33 kDa respectively. AGL-IA and IV agglutinated both rabbit and pronase treated human erythrocytes, whereas AGL-IB agglutinated only rabbit erythrocytes. AGL-III was found to agglutinate rabbit erythrocytes, however, it caused hemolysis of pronase treated human erythrocytes. The activity of all four lectins was calcium dependent and maximum at a pH range 7-8. Apart from Gal/GalNAc specific, the four lectins showed substantial differences in their carbohydrate recognition pattern. Moreover, there was a difference in the carbohydrate specificity between AGL-III and other three lectins (AGL-IA, AGL-IB and AGL-IV) towards polyvalent glycotope. On the one hand, 'cluster glycoside effect' i.e., an enhancement of the activity of a multivalent ligand, was observed for carbohydrate specificities of AGL-IA, AGL-IB, AGL-IV. On the other hand, the effect of multivalent ligands on the carbohydrate specificity of AGL-III was opposite of cluster glycoside effect. The affinity of AGL-IA, AGL-IB and AGL-IV for ligands can be ranked as follows: glycoproteins > polysaccharide > oligosaccharides and monosaccharides. However, Gal related monosaccharides were the best inhibitors of AGL-III and the inhibitory activity decreased gradually in the following order: monosaccharide > disaccharide > polysaccharide. Thus

  9. Bivalves and their control at the process water system in Embalse N.P.P

    International Nuclear Information System (INIS)

    Embalse NPP is a 648 Mwe CANDU®-600 type pressurized heavy water reactor (PHWR). The primary heat transport system (PHTS) has two separated heat transport circuits, each of them with two steam generators (SGs) of the recirculating type. The SGs have Alloy 800 tubes and the PHTS piping is made of carbon steel (CS). The primary coolant is lithiated heavy water pHa25oC = 10.2-10.4, hydrogen content 3-10 cm3/kg D2O. The Secondary Circuit (SC) has mixed metallurgy, i.e., copper alloys in the condenser tubing, Carbon Steel piping and Stainless Steel Alloys in some specific locations of the Steam/Water Cycle. In the Secondary Circuit ethanolamine is dosed for pH control and hydrazine for oxygen remosion. The process water and circulation water circuit (main condenser cooling water) source is fresh water from the Embalse Lake. As in other countries, bivalve larvae were transported to La Plata River, Parana River and then to other rivers and lakes located in the interior of the country. This caused serious inconveniences and concern not only in water intakes for drinking water production, but also in electric power production and manufacturing industries. During the observations and inspections that were carried out in different components of the Plant (pipes, heat exchangers), mollusks were found inside the process water and circulation water circuit. This phenomenon reached a peak in 2004 and 2005. Although experience has been taken from other countries, the products to be dosed must be the specific ones to be used in local organisms, local flora and fauna and environmental regulations. In order to study and control this problem, a research study was performed by experts from Buenos Aires Universities and a work plan was established, which consists in three stages: to construct a biobox, that is set in the circuit containing precolonized plates so as to obtain information about the efficiency and the conditions of use of chlorine and an alternative non-oxidizing toxic

  10. 76 FR 36363 - Hazardous Waste Manifest Printing Specifications Correction Rule

    Science.gov (United States)

    2011-06-22

    ... the marginal words indicating copy distribution must be printed with a distinct ink color or with... standardized manifest form during the promulgation of the March 4, 2005 Manifest Form Revisions Rule (70 FR... that ink color would help call attention to the copy distribution requirements and distinguish...

  11. Periodontal manifestation of epidermolysis bullosa: Looking through the lens

    OpenAIRE

    Praveen Kudva; Rajsi Jain

    2016-01-01

    Epidermolysis bullosa (EB) is a genetic disease associated with fragility and bullous lesions of the skin and mucous membranes. There are various patterns of inheritance and histopathology. The disease is associated with systemic and oral manifestations. Treatment of this disease is multidisciplinary and remains only palliative till today. The present case report describes periodontal manifestations of EB and the treatment plan for the same.

  12. 19 CFR 123.3 - Inward foreign manifest required.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Inward foreign manifest required. 123.3 Section 123.3 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS RELATIONS WITH CANADA AND MEXICO General Provisions § 123.3 Inward foreign manifest required. (a) General requirements....

  13. A Review of the Latent and Manifest Benefits (LAMB) Scale

    Science.gov (United States)

    Muller, Juanita; Waters, Lea

    2012-01-01

    The latent and manifest benefits (LAMB) scale (Muller, Creed, Waters & Machin, 2005) was designed to measure the latent and manifest benefits of employment and provide a single scale to test Jahoda's (1981) and Fryer's (1986) theories of unemployment. Since its publication in 2005 there have been 13 studies that have used the scale with 5692…

  14. Pulmonary arterial hypertension as a manifestation of lupus erythematosus

    International Nuclear Information System (INIS)

    We present five patients with systemic lupus erythematosus (SLE) who developed pulmonary arterial hypertension and cor pulmonale in the course of their disease. The clinical features, as well as, the radiological manifestations of this rare manifestation of SLE are discussed. A vasculitic process is the most likely cause of this complication. Therapy is ineffective and the prognosis is poor. (orig.)

  15. Achondroplasia: Craniofacial manifestations and considerations in dental management

    OpenAIRE

    Al-Saleem, Afnan; Al-Jobair, Asma

    2010-01-01

    Achondroplasia is the most common form of skeletal dysplasia dwarfism that manifests with stunted stature and disproportionate limb shortening. Achondroplasia is of dental interest because of its characteristic craniofacial features which include relative macrocephaly, depressed nasal bridge and maxillary hypoplasia. Presence of large head, implanted shunt, airway obstruction and difficulty in head control require special precautions during dental management. Craniofacial manifestations and c...

  16. Intestinal manifestations of angioneurotic edema. A case report

    International Nuclear Information System (INIS)

    We present a case of hereditary angioedema with cutaneous and intestinal manifestations mimicking as small bowel tumor on computed tomography, and in which unnecessary surgery was avoided by follow-up computed tomography. We discuss the pathophysiology, clinical and radiological manifestations of the disease, as well as its computed tomographic appearance. (authors)

  17. Orofacial manifestations of hematological disorders: Anemia and hemostatic disorders

    Directory of Open Access Journals (Sweden)

    Titilope A Adeyemo

    2011-01-01

    Full Text Available The aim of this paper is to review the literature and identify orofacial manifestations of hematological diseases, with particular reference to anemias and disorders of hemostasis. A computerized literature search using MEDLINE was conducted for published articles on orofacial manifestations of hematological diseases, with emphasis on anemia. Mesh phrases used in the search were: oral diseases AND anaemia; orofacial diseases AND anaemia; orofacial lesions AND anaemia; orofacial manifestations AND disorders of haemostasis. The Boolean operator "AND" was used to combine and narrow the searches. Anemic disorders associated with orofacial signs and symptoms include iron deficiency anemia, Plummer-Vinson syndrome, megaloblastic anemia, sickle cell anemia, thalassaemia and aplastic anemia. The manifestations include conjunctiva and facial pallor, atrophic glossitis, angular stomatitis, dysphagia, magenta tongue, midfacial overgrowth, osteoclerosis, osteomyelitis and paraesthesia/anesthesia of the mental nerve. Orofacial petechiae, conjunctivae hemorrhage, nose-bleeding, spontaneous and post-traumatic gingival hemorrhage and prolonged post-extraction bleeding are common orofacial manifestations of inherited hemostatic disorders such as von Willebrand′s disease and hemophilia. A wide array of anemic and hemostatic disorders encountered in internal medicine has manifestations in the oral cavity and the facial region. Most of these manifestations are non-specific, but should alert the hematologist and the dental surgeon to the possibilities of a concurrent disease of hemopoiesis or hemostasis or a latent one that may subsequently manifest itself.

  18. Corneal manifestations of selected systemic diseases: A review

    Directory of Open Access Journals (Sweden)

    Wayne D.H. Gillan

    2015-03-01

    Full Text Available The corneal manifestations of several selected systemic diseases are reviewed. Metabolic, immunologic and inflammatory and infectious diseases are included. A brief overview of each disease and how it manifests in the cornea is discussed. The importance of conducting a slit-lamp examination on every patient is emphasised.

  19. Uveitis as first manifestation of probably Crohn's disease

    Directory of Open Access Journals (Sweden)

    Ieda Maria Alexandre Barreira

    2012-12-01

    Full Text Available Extraintestinal manifestations of Crohn's disease are common. Although ocular complications of Crohn's disease are infrequent, most ocular manifestations include iritis, uveitis, episcleritis, scleritis and conjuntivitis. We report a patient who developed uveitis two years before diagnose of Crohn's disease.

  20. OCULAR MANIFESTATIONS IN SYSTEMIC LUPUS ERYTHEMATUSUS

    Directory of Open Access Journals (Sweden)

    Navalgunda

    2015-03-01

    - value being insignificant. CONCLUSION: There is significant percentage of patients who report with dermatological manifestations with SLE predominantly episcelritis.