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  • 1
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food safety 20 (2000), S. 0 
    ISSN: 1745-4565
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: In farm and food processing environments Escherichia coli O157:H7 can survive for days to months. In this study, we investigated the influence of starvation, pH (pH 4 or 7), temperature (4, 10 and 22C), and exposure to chlorine (50, 100, 150, 200 ppm) on culturability of E. coli O157:H7. The culturable cell population in PBS decreased to an undetectable level at 4C and 10C, but not at 22C during the experimental period. Cells suspended in PBS adjusted to pH 4 lost culturability more rapidly than at pH 7. Culturable cells were not detectable after exposure to chlorine, however, viable cell populations in the range of 1 – 2 log remained stable for 5 days. During loss of culturability two distinct morphological cell populations emerged; typical rod shaped and coccoid shaped cells. In this study, independent of exposure to chlorine, conditions of low temperature and low pH had the greatest influence on entry of E. coli O157:H7 into a VNC state.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    facet.materialart.
    Unbekannt
    PANGAEA
    In:  Supplement to: Zhao, Liqiang; Yang, Feng; Milano, Stefania; Han, Tiankun; Walliser, Eric Otto; Schöne, Bernd R (2018): Transgenerational acclimation to seawater acidification in the Manila clam Ruditapes philippinarum: Preferential uptake of metabolic carbon. Science of the Total Environment, 627, 95-103, https://doi.org/10.1016/j.scitotenv.2018.01.225
    Publikationsdatum: 2024-03-20
    Beschreibung: Ocean acidification may interfere with the calcifying physiology of marine bivalves. Therefore, understanding their capacity for acclimation and adaption to low pH over multiple generations is crucial to make predictions about the fate of this economically and ecologically important fauna in an acidifying ocean. Transgenerational exposure to an acidification scenario projected by the end of the century (i.e., pH 7.7) has been shown to confer resilience to juvenile offspring of the Manila clam, Ruditapes philippinarum. However, whether, and to what extent, this resilience can persist into adulthood are unknown and the mechanisms driving transgenerational acclimation remain poorly understood. The present study takes observations of Manila clam juveniles further into the adult stage and observes similar transgenerational responses. Under acidified conditions, clams originating from parents reproductively exposed to the same level of low pH show a significantly faster shell growth rate, a higher condition index and a lower standard metabolic rate than those without prior history of transgenerational acclimation. Further analyses of stable carbon isotopic signatures in dissolved inorganic carbon of seawater, individual soft tissues and shells reveal that up to 61% of shell carbonate comes from metabolic carbon, suggesting that transgenerationally acclimated clams may preferentially extract internal metabolic carbon rather than transport external seawater inorganic carbon to build shells, the latter known to be energetically expensive. While a large metabolic carbon contribution (45%) is seen in non-acclimated clams, a significant reduction in the rate of shell growth indicates it might occur at the expense of other calcification-relevant processes. It therefore seems plausible that, following transgenerational acclimation, R. philippinarum can implement a less costly and more efficient energy-utilizing strategy to mitigate the impact of seawater acidification. Collectively, our findings indicate that marine bivalves are more resilient to ocean acidification projected for the end of the century than previously thought.
    Schlagwort(e): Alkalinity, total; Alkalinity, total, standard deviation; Animalia; Aragonite saturation state; Aragonite saturation state, standard deviation; Benthic animals; Benthos; Bicarbonate ion; Bicarbonate ion, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Coast and continental shelf; Condition index; Condition index, standard deviation; Containers and aquaria (20-1000 L or 〈 1 m**2); EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater, standard deviation; Growth/Morphology; Growth rate; Growth rate, standard deviation; Laboratory experiment; Liangshui_Bay; Metabolic rate of oxygen; Metabolic rate of oxygen, standard deviation; Mollusca; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Other studied parameter or process; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Percentage; pH; pH, standard deviation; Registration number of species; Respiration; Ruditapes philippinarum; Salinity; Salinity, standard deviation; Single species; Species; Temperate; Temperature, water; Temperature, water, standard deviation; Treatment; Type; Uniform resource locator/link to reference; δ13C; δ13C, dissolved inorganic carbon; δ13C, dissolved inorganic carbon, standard deviation; δ13C, standard deviation
    Materialart: Dataset
    Format: text/tab-separated-values, 208 data points
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    facet.materialart.
    Unbekannt
    PANGAEA
    In:  Supplement to: Lu, Yanan; Wang, Li; Wang, Liangshu; Cong, Y; Yang, Guojun; Zhao, Liqiang (2018): Deciphering carbon sources of mussel shell carbonate under experimental ocean acidification and warming. Marine Environmental Research, 142, 141-146, https://doi.org/10.1016/j.marenvres.2018.10.007
    Publikationsdatum: 2024-03-15
    Beschreibung: Ocean acidification and warming is widely reported to affect the ability of marine bivalves to calcify, but little is known about the underlying mechanisms. In particular, the response of their calcifying fluid carbonate chemistry to changing seawater carbonate chemistry remains poorly understood. The present study deciphers sources of the dissolved inorganic carbon (DIC) in the calcifying fluid of the blue mussel (Mytilus edulis) reared at two pH (8.1 and 7.7) and temperature (16 and 22 °C) levels for five weeks. Stable carbon isotopic ratios of seawater DIC, mussel soft tissues and shells were measured to determine the relative contribution of seawater DIC and metabolically generated carbon to the internal calcifying DIC pool. At pH 8.1, the percentage of seawater DIC synthesized into shell carbonate decreases slightly from 83.8% to 80.3% as temperature increases from 16 to 22 °C. Under acidified conditions, estimates of percent seawater DIC incorporation decreases clearly to 65.6% at 16 °C and to 62.3% at 22 °C, respectively. These findings indicate that ongoing ocean acidification and warming may interfere with the calcification physiology of M. edulis through interfering with its ability to efficiently extract seawater DIC to the calcifying front.
    Schlagwort(e): Alkalinity, total; Alkalinity, total, standard error; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Biomass/Abundance/Elemental composition; Calcite saturation state; Calcite saturation state, standard error; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Laboratory experiment; Mollusca; Mytilus edulis; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; Percentage; pH; pH, standard error; Registration number of species; Salinity; Salinity, standard error; Single species; Species; Temperate; Temperature; Temperature, water; Temperature, water, standard error; Type; Uniform resource locator/link to reference; Xinghai_Bay; δ13C; δ13C, dissolved inorganic carbon; δ13C, dissolved inorganic carbon, standard deviation; δ13C, standard deviation
    Materialart: Dataset
    Format: text/tab-separated-values, 140 data points
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    facet.materialart.
    Unbekannt
    PANGAEA
    In:  Supplement to: Zhao, Liqiang; Liu, Baozhan; An, Wei; Deng, Yuewen; Lu, Yanan; Liu, Bingxin; Wang, Li; Cong, Yuting; Sun, Xin (2019): Assessing the impact of elevated pCO2 within and across generations in a highly invasive fouling mussel (Musculista senhousia). Science of the Total Environment, 689, 322-331, https://doi.org/10.1016/j.scitotenv.2019.06.466
    Publikationsdatum: 2024-03-15
    Beschreibung: Marine biofouling by the swiftly spreading invasive mussel (Musculista senhousia) has caused serious ecological and economic consequences in the global coastal waters. However, the fate of this highly invasive fouling species in a rapidly acidifying ocean remains unknown. Here, we demonstrated the impacts of ocean acidification within and across generations, to understand whether M. senhousia has the capacity to acclimate to changing ocean conditions. During the gonadal development, exposure of mussels to elevated pCO2 caused significant decreases of survival, growth performance and condition index, and shifted the whole-organism energy budget by inflating energy expenses to fuel compensatory processes, eventually impairing the success of spawning. Yet, rapid transgenerational acclimation occurred during the early life history stage and persisted into adulthood. Eggs spawned from CO2-exposed mussels were significantly bigger compared with those from non-CO2-exposed mussels, indicating increased maternal provisioning into eggs and hence conferring larvae resilience under harsh conditions. Larvae with a prior history of transgenerational exposure to elevated pCO2 developed faster and had a higher survival than those with no prior history of CO2 exposure. Transgenerational exposure significantly increased the number of larvae completing metamorphosis. While significant differences in shell growth were no longer observed during juvenile nursery and adult grow-out, transgenerationally exposed mussels displayed improved survival in comparison to non-transgenerationally exposed mussels. Metabolic plasticity arose following transgenerational acclimation, generating more energy available for fitness-related functions. Overall, the present study demonstrates the remarkable ability of M. senhousia to respond plastically and acclimate rapidly to changing ocean conditions.
    Schlagwort(e): Absorption efficiency; Absorption efficiency, standard deviation; Alkalinity, total; Ammonia excretion; Ammonia excretion, standard deviation; Animalia; Aragonite saturation state; Behaviour; Benthic animals; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Clearance rate; Clearance rate, standard deviation; Coast and continental shelf; Condition index; Condition index, standard deviation; Development; Duration; Egg size; Egg size, standard deviation; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Laboratory experiment; Metamorphosis rate; Metamorphosis rate, standard deviation; Mollusca; Mortality/Survival; Musculista senhousia; Nandaihe; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Other metabolic rates; Oxygen consumed/Nitrogen excreted ratio; Oxygen consumed/nitrogen excreted ratio, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Potentiometric; Potentiometric titration; Registration number of species; Reproduction; Respiration; Respiration rate, oxygen; Respiration rate, standard deviation; Salinity; Scope for growth; Scope for growth, standard deviation; Shell length; Shell length, standard deviation; Single species; Spawning rate; Spawning rate, standard deviation; Species; Survival; Survival rate, standard deviation; Temperate; Temperature, water; Time in days; Treatment; Type; Uniform resource locator/link to reference
    Materialart: Dataset
    Format: text/tab-separated-values, 1698 data points
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    facet.materialart.
    Unbekannt
    PANGAEA
    In:  Supplement to: Zhao, Liqiang; Schöne, Bernd R; Mertz-Kraus, Regina; Yang, Feng (2017): Sodium provides unique insights into transgenerational effects of ocean acidification on bivalve shell formation. Science of the Total Environment, 577, 360-366, https://doi.org/10.1016/j.scitotenv.2016.10.200
    Publikationsdatum: 2024-03-15
    Beschreibung: Ocean acidification is likely to have profound impacts on marine bivalves, especially on their early life stages. Therefore, it is imperative to know whether and to what extent bivalves will be able to acclimate or adapt to an acidifying ocean over multiple generations. Here, we show that reduced seawater pH projected for the end of this century (i.e., pH 7.7) led to a significant decrease of shell production of newly settled juvenile Manila clams, Ruditapes philippinarum. However, juveniles from parents exposed to low pH grew significantly faster than those from parents grown at ambient pH, exhibiting a rapid transgenerational acclimation to an acidic environment. The sodium composition of the shells may shed new light on the mechanisms responsible for beneficial transgenerational acclimation. Irrespective of parental exposure, the amount of Na incorporated into shells increased with decreasing pH, implying active removal of excessive protons through the Na+/H+ exchanger which is known to depend on the Na+ gradient actively built up by the Na+/K+-ATPase as a driving force. However, the shells with a prior history of transgenerational exposure to low pH recorded significantly lower amounts of Na than those with no history of acidic exposure. It therefore seems very likely that the clams may implement less costly and more ATP-efficient ion regulatory mechanisms to maintain pH homeostasis in the calcifying fluid following transgenerational acclimation. Our results suggest that marine bivalves may have a greater capacity to acclimate or adapt to ocean acidification by the end of this century than currently understood.
    Schlagwort(e): Acid-base regulation; Alkalinity, total; Alkalinity, total, standard error; Animalia; Aragonite saturation state; Aragonite saturation state, standard error; Benthic animals; Benthos; Bicarbonate ion; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Laboratory experiment; Liangshui_Bay; Mollusca; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; pH; pH, standard error; Registration number of species; Ruditapes philippinarum; Salinity; Salinity, standard error; Sample ID; Single species; Sodium/Calcium ratio; Species; Temperate; Temperature, water; Temperature, water, standard error; Treatment; Type; Uniform resource locator/link to reference
    Materialart: Dataset
    Format: text/tab-separated-values, 2400 data points
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
    facet.materialart.
    Unbekannt
    PANGAEA
    In:  Supplement to: Xu, Xian; Yang, Feng; Zhao, Liqiang; Yan, Xiwu (2016): Seawater acidification affects the physiological energetics and spawning capacity of the Manila clam Ruditapes philippinarum during gonadal maturation. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 196, 20-29, https://doi.org/10.1016/j.cbpa.2016.02.014
    Publikationsdatum: 2024-03-15
    Beschreibung: Ocean acidification is predicted to have widespread implications for marine bivalve mollusks. While our understanding of its impact on their physiological and behavioral responses is increasing, little is known about their reproductive responses under future scenarios of anthropogenic climate change. In this study, we examined the physiological energetics of the Manila clam Ruditapes philippinarum exposed to CO2-induced seawater acidification during gonadal maturation. Three recirculating systems filled with 600 L of seawater were manipulated to three pH levels (8.0, 7.7, and 7.4) corresponding to control and projected pH levels for 2100 and 2300. In each system, temperature was gradually increased ca. 0.3 °C per day from 10 to 20 °C for 30 days and maintained at 20 °C for the following 40 days. Irrespective of seawater pH levels, clearance rate (CR), respiration rate (RR), ammonia excretion rate (ER), and scope for growth (SFG) increased after a 30-day stepwise warming protocol. When seawater pH was reduced, CR, ratio of oxygen to nitrogen, and SFG significantly decreased concurrently, whereas ammonia ER increased. RR was virtually unaffected under acidified conditions. Neither temperature nor acidification showed a significant effect on food absorption efficiency. Our findings indicate that energy is allocated away from reproduction under reduced seawater pH, potentially resulting in an impaired or suppressed reproductive function. This interpretation is based on the fact that spawning was induced in only 56% of the clams grown at pH 7.4. Seawater acidification can therefore potentially impair the physiological energetics and spawning capacity of R. philippinarum.
    Schlagwort(e): Absorption efficiency; Absorption efficiency, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Ammonia excretion, standard deviation; Ammonia excretion per individual; Animalia; Aragonite saturation state; Aragonite saturation state, standard deviation; Behaviour; Benthic animals; Benthos; Bicarbonate ion; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Clearance rate, standard deviation; Clearance rate per individual; Coast and continental shelf; Condition index; Condition index, standard deviation; Containers and aquaria (20-1000 L or 〈 1 m**2); Date; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Laboratory experiment; Liangshui_Bay; Mollusca; Mortality; Mortality/Survival; OA-ICC; Ocean Acidification International Coordination Centre; Other metabolic rates; Oxygen consumed/Nitrogen excreted ratio; Oxygen consumed/nitrogen excreted ratio, standard deviation; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH, standard deviation; Registration number of species; Reproduction; Respiration; Respiration rate, oxygen, per individual; Respiration rate, standard deviation; Ruditapes philippinarum; Salinity; Scope for growth; Scope for growth, standard deviation; Single species; South Pacific; Spawning rate; Spawning rate, standard deviation; Species; Temperate; Temperature; Temperature, water; Time in days; Treatment; Type; Uniform resource locator/link to reference
    Materialart: Dataset
    Format: text/tab-separated-values, 6906 data points
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    facet.materialart.
    Unbekannt
    PANGAEA
    In:  Supplement to: Zhao, Liqiang; Schöne, Bernd R; Mertz-Kraus, Regina; Yang, Feng (2017): Insights from sodium into the impacts of elevated pCO2 and temperature on bivalve shell formation. Journal of Experimental Marine Biology and Ecology, 486, 148-154, https://doi.org/10.1016/j.jembe.2016.10.009
    Publikationsdatum: 2024-03-15
    Beschreibung: Ocean acidification and warming are predicted to affect the ability of marine bivalves to build their shells, but little is known about the underlying mechanisms. Shell formation is an extremely complex process requiring a detailed understanding of biomineralization processes. Sodium incorporation into the shells would increase if bivalves rely on the exchange of Na+/H+ to maintain homeostasis for shell formation, thereby shedding new light on the acid-base and ionic regulation at the calcifying front. Here, we investigated the combined effects of seawater pH (8.1, 7.7 and 7.4) and temperature (16 and 22 °C) on the growth and sodium composition of the shells of the blue mussel, Mytilus edulis, and the Yesso scallop, Patinopecten yessoensis. Exposure of M. edulis to low pH (7.7 and 7.4) caused a significant decrease of shell formation, whereas a 6 °C warming significantly depressed the rate of shell growth in P. yessoensis. On the other hand, while the amount of Na incorporated into the shells of P. yessoensis did not increase in acidified seawater, an increase of Na/Cashell with decreasing pH was observed in M. edulis, the latter agreeing well with the aforementioned hypothesis. Moreover, a combined analysis of the shell growth and sodium content provides a more detailed understanding of shell formation processes. Under acidified conditions, mussels may maintain more alkaline conditions favorable for calcification, but a significant decrease of shell formation indicates that the mineralization processes are impaired. The opposite occurs in scallops; virtually unaffected shell growth implies that shell mineralization functions well. Finding of the present study may pave the way for deciphering the mechanisms underlying the impacts of ocean acidification and warming on bivalve shell formation.
    Schlagwort(e): Alkalinity, total; Alkalinity, total, standard error; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Calcification/Dissolution; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); Event label; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Growth rate, standard deviation; Laboratory experiment; Mollusca; Mytilus edulis; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; Patinopecten yessoensis; pH; pH, standard error; Potentiometric titration; Registration number of species; Salinity; Salinity, standard error; Single species; Sodium/Calcium ratio; Species; Temperate; Temperature; Temperature, water; Temperature, water, standard error; Treatment; Type; Uniform resource locator/link to reference; Xinghai_Bay; Zhangzi_Island
    Materialart: Dataset
    Format: text/tab-separated-values, 348 data points
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 8
    Publikationsdatum: 2024-02-07
    Beschreibung: Oxygen depletion threatens an increasing number of shallow water environments, specifically habitats below the seasonal halocline in coastal settings of the Baltic Sea. To understand the natural variations of dissolved oxygen levels on seasonal and inter-annual time-scales prior to the instrumental era, high-resolution archives are urgently required. The present study evaluates the potential use of Mn/Ca values in shells of the bivalve, Arctica islandica to infer concentrations of past dissolved oxygen concentrations. This study is based on laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) data of six contemporaneous specimens and demonstrates that background variations of shell Mn/Ca are inversely linked to dissolved oxygen concentrations in the water column (r = −0.68; R2 = 0.46, p 〈 0.0001), which in turn are coupled to the amount of dissolved Mn. The regular seasonal changes were superimposed by sharp Mn/Ca peaks, most likely resulting from the ingestion of a large amount of Mn-rich organic particles. The availability of such particles can increase due to the resuspension of food particles by strong bottom currents or alternatively, result from increased particle flux from surface waters after major river discharges and subsequent phytoplankton blooms. Besides sharp Mn/Ca peaks, often accompanied by sharp Ba/Ca peaks and increased shell growth rate. In addition, after exceptional major barotropic inflows from the North Sea, the biogeochemical steady-state conditions remained disturbed for up to ca. two years, because the redox-sensitive elements were removed from the water column by oxygenated waters, and it took time for them to build up again in the water column. Therefore, subsequent to such Major Baltic Inflows (MBIs), dissolved Mn levels and shell Mn/Ca values were strongly reduced despite summertime low-oxygen conditions. As demonstrated here, Mn/Ca data of A. islandica shells can potentially serve as a proxy for dissolved oxygen levels in the water column. To further develop this proxy, a set of additional environmental and physiological proxies such as shell Ba/Ca values and growth rate should be critically assessed and used in combination with shell Mn/Ca.
    Materialart: Article , PeerReviewed
    Format: text
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 9
    Publikationsdatum: 2018-11-07
    Beschreibung: The electronic structure, photocatalytic properties and mechanism of Cu 2 O with different Co-doped concentrations in visible light region are studied by first-principles calculation. The results show that intrinsic Cu 2 O shows semiconductor characteristics, and the Co doped Cu 2 O with 4.17% and 8.33% doping concentrations show metallic properties. The light absorption of Cu 2 O in the visible region increases with the Co doping, and the photocatalytic efficiency enhances with increasing doping concentration. By analyzing the density of states, it is found that the enhanced light absorption of the two doped systems in the visible range is mainly caused by the intraband transition of Co 3d state electrons. The results found an effective way to improve the photocatalytic efficiency of Cu 2 O in the visible region and promote the application of Cu 2 O in photocatalysis.
    Print ISSN: 1755-1307
    Digitale ISSN: 1755-1315
    Thema: Geographie , Geologie und Paläontologie , Physik
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 10
    Publikationsdatum: 2013-06-12
    Beschreibung: Chiral nanoscale photonic systems typically follow either tetrahedral or helical geometries that require four or more different constituent nanoparticles. Smaller number of particles and different chiral geometries taking advantage of the self-organization capabilities of nanomaterials will advance understanding of chiral plasmonic effects, facilitate development of their theory, and stimulate practical applications of chiroplasmonics. Here we show that gold nanorods self-assemble into side-by-side orientated pairs and “ladders” in which chiral properties originate from the small dihedral angle between them. Spontaneous twisting of one nanorod versus the other one breaks the centrosymmetric nature of the parallel assemblies. Two possible enantiomeric conformations with positive and negative dihedral angles were obtained with different assembly triggers. The chiral nature of the angled nanorod pairs was confirmed by 4π full space simulations and the first example of single-particle CD spectroscopy. Self-assembled nanorod pairs and “ladders” enable the development of chiral metamaterials, (bio)sensors, and new catalytic processes. Scientific Reports 3 doi: 10.1038/srep01934
    Digitale ISSN: 2045-2322
    Thema: Allgemeine Naturwissenschaft
    Standort Signatur Einschränkungen Verfügbarkeit
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