308 research outputs found
Deployment characterization of a floatable tidal energy converter on a tidal channel, Ria Formosa, Portugal
This paper presents the results of a pilot experiment with an existing tidal energy converter (TEC),
Evopod 1 kW floatable prototype, in a real test case scenario (Faro Channel, Ria Formosa, Portugal). A
baseline marine geophysical, hydrodynamic and ecological study based on the experience collected on
the test site is presented. The collected data was used to validate a hydro-morphodynamic model,
allowing the selection of the installation area based on both operational and environmental constraints.
Operational results related to the description of power generation capacity, energy capture area and
proportion of energy flux are presented and discussed, including the failures occurring during the
experimental setup. The data is now available to the scientific community and to TEC industry developers,
enhancing the operational knowledge of TEC technology concerning efficiency, environmental
effects, and interactions (i.e. device/environment). The results can be used by developers on the licensing
process, on overcoming the commercial deployment barriers, on offering extra assurance and confidence
to investors, who traditionally have seen environmental concerns as a barrier, and on providing the
foundations whereupon similar deployment areas can be considered around the world for marine tidal
energy extraction.Acknowledgements
The paper is a contribution to the SCORE project, funded by the
Portuguese Foundation for Science and Technology (FCT e PTDC/
AAG-TEC/1710/2014). Andre Pacheco was supported by the Portu-
guese Foundation for Science and Technology under the Portuguese
Researchers' Programme 2014 entitled âExploring new concepts for
extracting energy from tidesâ (IF/00286/2014/CP1234). Eduardo GGorbena has received funding for the OpTiCA project from the ~
Marie SkĆodowska-Curie Actions of the European Union's H2020-
MSCA-IF-EF-RI-2016/under REA grant agreement n [748747]. The
authors would like to thank to the Portuguese Maritime Authorities
and Sofareia SA for their help on the deployment.info:eu-repo/semantics/publishedVersio
Isolated Splenic Metastasis from Rectal Carcinoma: A Rare Occurrence
The presence of isolated splenic metastasis in rectal carcinoma is uncommon and usually presents as an asymptomatic mass, noted incidentally on imaging. Splenectomy is usually performed with the goal of curing metastatic disease. It is unclear if adjuvant chemotherapy affords any benefit, and the prognosis is unknown. The case of a young woman is reported, in whom an isolated metastatic lesion in the spleen was discovered 9 months after adjuvant chemotherapy for stage III rectal adenocarcinoma. The patient has remained disease-free for nearly 5 years following splenectomy and chemotherapy. To our knowledge, this is the fourth reported case in the English literature of an isolated splenic metastatic lesion from rectal cancer. We discuss the unique presentation, the importance of post-treatment surveillance, and the implementation of multi-modality treatment strategies in this young patient
Short-Term Pain and Long-Term Gain: Using Phased-In Minimum Size Limits to Rebuild Stocks-the Pacific Bluefin Tuna Example
Like many stocks, the Pacific Bluefin Tuna Thunnus orientalis has been considerably depleted. High exploitation rates on very young fish have reduced the spawning stock biomass (SSB) to 2.6% of the unexploited level. We provide a framework for exploring potential benefits of minimum size regulations as a mechanism for rebuilding stocks, and we illustrate the approach using simulations patterned after Pacific Bluefin Tuna dynamics. We attempt to mitigate short-term losses in yield by considering a phased-in management strategy. With this approach, the minimum size limit (MSL) is gradually increased as biomass rebuilds, giving fishing communities time to adjust to new restrictions. We estimated short- and long-term effects of different MSLs on yield and biomass by using data from the 2016 assessment. A variety of scenarios was considered for growth compensation, discard mortality, and interest rates. The long-term value of the fishery was maximized by setting an MSL of 92 cm FL, which resulted in a 70% loss in yield during the first year (short-term pain). By implementing the MSL in two phases (64 cm FL in year 1; 92 cm FL in subsequent years), the long-term value of the fishery was maintained, and the short-term pain was reduced to a maximum 46% loss in yield during any 1 year. Under a three-phase implementation (55 cm FL in year 1; 77 cm FL in year 2; and 92 cm FL in subsequent years), the short-term pain was further reduced to a maximum loss of 30% during any 1 year. With no discard mortality, long-term yield increased by 165% and SSB increased 13-fold (to 33% of virgin SSB), regardless of the number of phases used. Long-term benefits were quickly diminished with increasing discard mortality. This simulation approach is widely applicable to cases where minimum size changes are contemplated; for Pacific Bluefin Tuna, our simulations demonstrate that size limits should be considered
North Pacific-wide spreading of isotopically heavy nitrogen during the last deglaciation: Evidence from the western Pacific
Sedimentary delta(15) N records in two IMAGES cores (MD012404 and MD012403) retrieved from the Okinawa Trough (OT) in the western North Pacific reveal deglacial increases with two peaks occurring during the Bolling/Allerod and the Preboreal/early Holocene periods. These peaks are synchronous with previously reported delta(15) N peaks in the Eastern Tropical North Pacific, although the amplitudes (from 3.8 to 5.8%) are much smaller in the OT. Similar delta(15) N values for the last glacial maximum and the late-Holocene observed by us at a site far from the present-day zones of water-column denitrification (WCD) indicate that the mean N-15/N-14 of nitrate in the upper ocean did not differ much between the two climate states. The accumulation rate of organic carbon and total sulfur content are used as indices of the local WCD potential. The results suggest that enhancement of global WCD rather than local denitrification should be responsible for the deglacial maxima of sedimentary delta(15) N in the Okinawa Trough. Our data could provide additional constraints to better understand changes in nitrogen budget during the glacial to interglacial transition.National Science Council of Taiwan [NSC 96-2611-M-001-005]; State Key Laboratory of Marine Environmental Science, ; Xiamen University, Xiame
Gold-iron oxide (Au/Fe3O4) magnetic nanoparticles as the nanoplatform for binding of bioactive molecules through self-assembly
Nanomedicine plays a crucial role in the development of next-generation therapies. The use of nanoparticles as drug delivery platforms has become a major area of research in nanotechnology. To be effective, these nanoparticles must interact with desired drug molecules and release them at targeted sites. The design of these ânanoplatformsâ typically includes a functional core, an organic coating with functional groups for drug binding, and the drugs or bioactive molecules themselves. However, by exploiting the coordination chemistry between organic molecules and transition metal centers, the self-assembly of drugs onto the nanoplatform surfaces can bypass the need for an organic coating, simplifying the materials synthesis process. In this perspective, we use gold-iron oxide nanoplatforms as examples and outline the prospects and challenges of using self-assembly to prepare drug-nanoparticle constructs. Through a case study on the binding of insulin on Au-dotted Fe3O4 nanoparticles, we demonstrate how a self-assembly system can be developed. This method can also be adapted to other combinations of transition metals, with the potential for scaling up. Furthermore, the self-assembly method can also be considered as a greener alternative to traditional methods, reducing the use of chemicals and solvents. In light of the current climate of environmental awareness, this shift towards sustainability in the pharmaceutical industry would be welcomed
Physicians' social competence in the provision of care to persons living in poverty: research protocol
Eastern Pacific Warm Pool paleosalinity and climate variability : 0â30 kyr
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 21 (2006): PA3008, doi:10.1029/2005PA001208.Multi-proxy geologic records of Ύ18O and Mg/Ca in fossil foraminifera from
sediments under the Eastern Pacific Warm Pool (EPWP) region west of Central America
document variations in upper ocean temperature, pycnocline strength, and salinity (i.e., net precipitation) over the past 30 ky. Although evident in the paleotemperature record,
there is no glacial-interglacial difference in paleosalinity, suggesting that tropical
hydrologic changes do not respond passively to high-latitude ice sheets and oceans.
Millennial variations in paleosalinity with amplitudes as high as ~4 PSU occur with a
dominant period of ~3-5 ky during the glacial/deglacial interval and ~1.0-1.5 ky during the Holocene. The amplitude of the EPWP paleosalinity changes greatly exceeds that of published Caribbean and western tropical Pacific paleosalinity records. EPWP
paleosalinity changes correspond to millennial-scale climate changes in the surface and
deep Atlantic and the high northern latitudes, with generally higher (lower) paleosalinity during cold (warm) events. In addition to Intertropical Convergence Zone (ITCZ) dynamics, which play an important role in tropical hydrologic variability, changes in Atlantic-Pacific moisture transport, which is closely linked to ITCZ dynamics, may also
contribute to hydrologic variations in the EPWP. Calculations of interbasin salinity
average and interbasin salinity contrast between the EPWP and the Caribbean help
differentiate long-term changes in mean ITCZ position and Atlantic-Pacific moisture
transport, respectively.Support for this research was provided by the U.S. National Science Foundation
Pacific Oceanâwide profile of CYP1A1 expression, stable carbon and nitrogen isotope ratios, and organic contaminant burden in sperm whale skin biopsies
This paper is not subject to U.S. copyright. The definitive version was published in Environmental Health Perspectives 119 (2011): 337-343, doi:10.1289/ehp.0901809.Background: Ocean pollution affects marine organisms and ecosystems as well as humans. The International Oceanographic Commission recommends ocean health monitoring programs to investigate the presence of marine contaminants and the health of threatened species and the use of multiple and early-warning biomarker approaches.
Objective: We explored the hypothesis that biomarker and contaminant analyses in skin biopsies of the threatened sperm whale (Physeter macrocephalus) could reveal geographical trends in exposure on an oceanwide scale.
Methods: We analyzed cytochrome P450 1A1 (CYP1A1) expression (by immunohistochemistry), stable nitrogen and carbon isotope ratios (as general indicators of trophic position and latitude, respectively), and contaminant burdens in skin biopsies to explore regional trends in the Pacific Ocean.
Results: Biomarker analyses revealed significant regional differences within the Pacific Ocean. CYP1A1 expression was highest in whales from the Galapagos, a United Nations Educational, Scientific, and Cultural Organization World Heritage marine reserve, and was lowest in the sampling sites farthest away from continents. We examined the possible influence of the whalesâ sex, diet, or range and other parameters on regional variation in CYP1A1 expression, but data were inconclusive. In general, CYP1A1 expression was not significantly correlated with contaminant burdens in blubber. However, small sample sizes precluded detailed chemical analyses, and power to detect significant associations was limited.
Conclusions: Our large-scale monitoring study was successful at identifying regional differences in CYP1A1 expression, providing a baseline for this known biomarker of exposure to aryl hydrocarbon receptor agonists. However, we could not identify factors that explained this variation. Future oceanwide CYP1A1 expression profiles in cetacean skin biopsies are warranted and could reveal whether globally distributed chemicals occur at biochemically relevant concentrations on a global basis, which may provide a measure of ocean integrity.Funding was provided by National Institute of Environmental Health Sciences grant P42-ES-0469, Superfund Basic Research Program grant P42ES007381, NOAA Sea Grant NA86RG0075 R/B-162, and the Ocean Alliance
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