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Ocean conditions and bottom-up modifications of gonad development in the sea urchin Strongylocentrotus purpuratus over space and time
Get PDFIntraspecific life history attributes of growth, survival, and reproduction can vary in
response to changes in the physical environment. These changes can induce a cascading effect
across trophic levels. In marine systems, shifts in ocean conditions such as warm and cold phases
of ENSO can change primary production in benthic algae, which in turn modify resources
available to benthic omnivores. Monthly gonad samples of the purple sea urchin,
Strongylocentrotus purpuratus, were taken during from 2007 to mid 2009 at sites from
Vancouver Island, Canada, to Punta Baja, México. Although mean sea surface temperature, SST,
changed by about 8°C from north to south latitudinal patterns of size-specific gonad weight were
not detected. There were, however, differences across sites. At individual sites, mean SST
changed by less than 1° C from 2007 to 2009. Gonad Index data from Yankee Point, California,
from 1952–64 included mean annual temperatures that varied by 2.4°C and both strong El Niño
and La Niña events. Yankee Point data showed significant (P≤0.01) correlations with the
Multivariate ENSO Index (MEI and MEI.ext), sea surface temperature (SST), the Northern
Oscillation Index (NOI), and the Oceanic Niño Index (ONI). Dissections at other sites along the
coast from mid 1960 to 2009 showed that size-specific gonad weights were smaller during
periods of El Niño than during periods of La Niña.Keywords: sea surface temperature, ENSO, Strongylocentrotus purpuratus, Pacific coast, sea urchin, intertidal, bottom-up, allometry, latitudinal patterns, Multivariate ENSO Index, gonad cycl
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No full textThe northern Los Angeles basin is influenced by two structural styles: the west-trending compressional Transverse Ranges to the north, and the strike-slip Peninsular Ranges to the south. The interaction of these two structural styles has resulted in a complex fold fault belt at the northern margin of the Los Angeles basin, which deforms a variable sequence of late Miocene through Quaternary marine strata. Subsurface mapping of Quaternary marine gravels by electric-log correlation documents the latest phase of deformation in the northern Los Angeles basin. The Quaternary marine gravels are folded at the Wilshire arch, the Hollywood basin, the central trough, the Newport-Inglewood fault, and the Santa Monica fault. The west-plunging Wilshire arch, which follows Wilshire Boulevard east of the Newport- Inglewood fault, is a broad fold identified and named in this study. Deformation of the Wilshire arch, which is underlain and caused by the potentially-seismogenic Wilshire fault, began around 0.8 - 1.0 Ma. A fault-bend fold model, based on the shape of the Wilshire arch, indicates a dip-slip rate of 1.5 - 1.9 mm yr for the Wilshire fault, whereas a three-dimensional elastic dislocation model indicates a right-reverse slip rate of 2.6 - 3.2 mm per year for the Wilshire fault. The finer-grained marine Pliocene strata include the late Pliocene to early Pleistocene Pico member, and the early Pliocene Repetto member, of the Fernando Formation. Thickness and lithology variations in the Pico and Repetto strata, which were influenced by syndepositional structures, indicate that the entire Pliocene and the latest Miocene were characterized by compression. The primary structure present throughout the Pliocene is a south-dipping monocline, which was underlain and caused by a deep reverse fault, dipping ~55 - 60° to the north, referred to here as the Monocline fault. Relative subsidence of the central trough resulted in deposition of up to 7000 ft (2135 m) of Pico strata, and up to 5000 ft (1525 m) of Repetto strata, compared to zero deposition on the monoclinal high. In the western part of the study area, the south-dipping monocline is interrupted by the secondary East Beverly Hills fold, which may be a rabbit-ear fold that accommodates excess volume by bedding-parallel slip. The East Beverly Hills fold was active in the latest Miocene through Pliocene, and was most active during early Pliocene Repetto deposition. In the eastern part of the study area, the monocline is interrupted by the Las Cienegas fold, which formed in the hangingwall of the Las Cienegas fault. The Las Cienegas fault was a normal fault in the late Miocene, and was reactivated in the Pliocene as a steep reverse fault. Folding and uplift on the Las Cienegas anticline occurred throughout the Pliocene, with the greatest amount occurring during lower and lower-middle Pico deposition.The northern Los Angeles basin is influenced by two structural styles: the west-trending compressional Transverse Ranges to the nort
Tragedy of the Commons and International Trade: Case of International Fisheries
Get PDFIn the globalizing era, world trade of fishery resources has sharply increased. Because capture fisheries are hard to be managed, growing opportunity for fishery trade may cause the overexploitation of world fishery resources. For instance, the theoretical model developed by Takarada et al (2009, mimeograph) implies that fish stocks may be overexploited when they are traded. In our paper, we examine empirically the effect of trade on the exploitation of fish stocks. The empirical framework is based on the model of McWhinnie (2009, J. Env. Econ & Man 57.3), and we extend her model to examine the relationship between exploitation and fishery trade, instead of internationally sharing. The empirical results by using disaggregated data of fishery trade in EU (HS 6- digit level) and exploitation information by FAO and Sea Around Us Project imply that the fish stocks are likely to be overexploited when they are traded. These results, which are consistent with the theoretical consequence by Takarada et al., suggest that fishery stocks should be more effectively managed to prevent overexploitation.Keywords: Fisheries Economics, Fish and Aquaculture Sectors Development, Contributions of Fisheries to Socioeconomic Wellbein
Fouling Prevention_Theisis Presentation 2014_ Gollmann.pptx.pdf
No full textForward osmosis provides a low energy alternative for waste water purification. One of the major issues facing this process is the formation of a foulant layer preventing fluid transfer across the membrane. In recent studies, a conductive layer added to the membrane surface allowing an electric charge to be present on the membrane, has been shown to decrease the rate of mineral fouling in reverse osmosis membranes. Through the application of a conductive layer made of carbon nanotubes on Hydration Technology Innovations, LLC. thin film composite membrane, the applicability of the charged surface and its effects on mineral fouling was explored for forward osmosis membranes. Extensive testing was done by placing both positive and negative charges on the membrane with varying voltage potentials. This method of fouling prevention was found to have little observable effect on the membranes resistance to mineral foulants.Keywords: Forward osmosis, Charged membrane surface, Fouling, Mineral scalingKeywords: Forward osmosis, Charged membrane surface, Fouling, Mineral scalin
Developmentally distinct activities of the exocyst enable rapid cell elongation and determine meristem size during primary root growth in Arabidopsis
Get PDFBACKGROUND: Exocytosis is integral to root growth: trafficking components of systems that control growth (e.g., PIN auxin transport proteins) to the plasma membrane, and secreting materials that expand the cell wall to the apoplast. Spatiotemporal regulation of exocytosis in eukaryotes often involves the exocyst, an octameric complex that tethers selected secretory vesicles to specific sites on the plasma membrane and facilitates their exocytosis. We evaluated Arabidopsis lines with mutations in four exocyst components (SEC5, SEC8, EXO70A1 and EXO84B) to explore exocyst function in primary root growth. RESULTS: The mutants have root growth rates that are 82% to 11% of wild-type. Even in lines with the most severe defects, the organization of the quiescent center and tissue layers at the root tips appears similar to wild-type, although meristematic, transition, and elongation zones are shorter. Reduced cell production rates in the mutants are due to the shorter meristems, but not to lengthened cell cycles. Additionally, mutants demonstrate reduced anisotropic cell expansion in the elongation zone, but not the meristematic zone, resulting in shorter mature cells that are similar in shape to wild-type. As expected, hypersensitivity to brefeldin A links the mutant root growth defect to altered vesicular trafficking. Several experimental approaches (e.g., dose–response measurements, localization of signaling components) failed to identify aberrant auxin or brassinosteroid signaling as a primary driver for reduced root growth in exocyst mutants. CONCLUSIONS: The exocyst participates in two spatially distinct developmental processes, apparently by mechanisms not directly linked to auxin or brassinosteroid signaling pathways, to help establish root meristem size, and to facilitate rapid cell expansion in the elongation zone.Keywords: Auxin, Meristem, Cell expansion, Brassinosteroid, Exocyst, Root growt
Maintaining woodland roads [1997]
No full textIgnoring or delaying necessary maintenance can lead to damage that is more costly to repair than the original road construction. Good maintenance also helps ensure safety and necessary access, and it enhances the efficiency of vehicle and equipment travel over your property.Keywords: Logging, Woodland RoadsFacts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo
PaulrajPrawin.Mechanical Industrial & Manufacturing Engineering.Metal Microchannel Lamination.Manuscript.pdf
No full textThis paper reports the feasibility of using surface mount adhesives to produce low temperature microchannel arrays in a wide variety of metals. Sheet metal embossing and chemical etching processes have been used to produce sealing bosses that eliminate channel laminae, resulting in approximately 50% material savings over traditional methods. An assembly process using adhesive dispense and cure is outlined to produce leak-free devices. Optimal fill ratios were determined to be between 1.1 and 1.25. Bond strength investigation reveals robustness to surface conditions and a bond strength of 5.5-8.5 MPa using a 3X safety factor. Dimensional characterization reveals a two sigma (95%) post-bonded channel height tolerance under 10% after bonding. Patterning tolerance and surface roughness of the laminae faying surfaces were found to have a significant influence on the final post-bonded channel height. Leakage and burst pressure testing on several samples has established confidence that adhesive bonding can produce leak-free joints. Operating pressures up to 413 kPa have been satisfied equating to tensile pressure on bond joints of 1.9 MPa. Higher operating pressures can be accommodated by increasing the bond area of devices
Fertilizing shade and ornamental trees [2000]
No full textYoung trees (those with a trunk diameter of less than 6 inches) can benefit greatly from regular applications of fertilizer. Research has shown that when these trees receive nitrogen fertilizer, they grow faster, develop a denser canopy, and stay green longer into the fall.Published August 2000. Reviewed December 2014. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo
Geochemical alteration of simulated wellbores of CO₂ injection sites within the Illinois and Pasco Basins
Get PDFGeologic carbon sequestration is being considered in target basalt and sandstone formations. The chemical
effects of CO2 exposure on the interface between Class H Portland cement paste and Grande Ronde
Columbia River basalt, or between cement paste and Mt. Simon sandstone, has been examined at a
microstructural level. This bonding interface is a potential leakage pathway for CO2 along a wellbore.
The salinities of the formation solutions, basaltic Pasco Basin formation water (0.013 M), whereas the
sandstone Illinois Basin brine (1.28 M), play a large role in CO2 solubility and cement alteration. Experimental
cement-rock-fluid charges were held at 35 ◦C and PCO2
=
10 MPa for up to 84 days, conditions
under which the fluids are CO2-saturated. The basalt-cement experiment had
∼1 mm alteration at the
interface and high levels of alteration of the cement paste exterior. The sandstone sample displayed less
alteration at the cement paste interface. Geochemical modeling conducted with CHIM-XPT calculated
the pH of the Pasco brine solution (basalt only) to be 12.23 with 50 g of CO2 (104 bar) and 161 g (306 bar).
The pH of the Pasco solution (cement + basalt) started with at 11.82 and ended at 4.52 after 136 g of
CO2(g) dissolved in solution, resulting in the precipitation of magnesite, calcite, and siderite. The basalt
has high capacity to convert CO2 into minerals. The Illinois Basin brine containing Mt. Simon sandstone
and cement paste never exceeded a pH of 5.8, had an estimated 139 g of CO2 with high capacity to store
aqueous and brine-saturated CO2 and a lower risk of alteration to hardened cement paste.Keywords: Sandstone, CO₂ sequestration, Basalt, Class H Portland cemen
Barents Sea capelin and cod stock scenarios: Testing biological consequences of economical based management
Get PDFWe present a scenario-model for the joint Norwegian and Russian managed capelin and cod stocks in the Barents Sea. The model basically consists of two sub models. The first is an autonomous management model which, based on profit functions and growth functions with coefficients calibrated from real data, finds a feedback rule for maximizing the Norwegian share of the fishery rent by using numerical dynamic programming. The second (Bifrost) is a biological multi-species growth model provided by the Institute of Marine Resources. This model has higher resolution than the simple top-down growth used in the management model. With this we simulate possible scenarios resulting from employing the management model as decision making instrument in the real world. Doing so, we concentrate on possible future catch and stock sizes rather than on economics. Scenarios from six different strategies are tested, of which two of them is pure biological and inspired from existing management. Bifrost is applied direct to measure total allow catch (TAC) in these strategies, whereas the four economic strategies are found from the management model. These strategies are compared with the biologic strategies and the results are rather promising on the behalf of the economical strategies.Keywords: Barents Sea, Economical based management, Capelin and cod stocks, Biological consequences, Fisheries Economic