Showing papers by "Oregon State University published in 1979"

Submarine Thermal Springs on the Galápagos Rift

Abstract: The submarine hydrothermal activity on and near the Galapagos Rift has been explored with the aid of the deep submersible Alvin Analyses of water samples from hydrothermal vents reveal that hydrothermal activity provides significant or dominant sources and sinks for several components of seawater; studies of conductive and convective heat transfer suggest that two-thirds of the heat lost from new oceanic lithosphere at the Galapagos Rift in the first million years may be vented from thermal springs, predominantly along the axial ridge within the rift valley The vent areas are populated by animal communities They appear to utilize chemosynthesis by sulfur-oxidizing bacteria to derive their entire energy supply from reactions between the seawater and the rocks at high temperatures, rather than photosynthesis

A Physical Concept of Soil-Water Equilibria for Nonionic Organic Compounds

Abstract: Soil-water equilibrium data suggest that the transfer of nonionic chemicals from water to soil may be described in terms of a hypothesis of solute partitioning in the soil organic matter. This concept allows estimation of soil-water distribution coefficients either from solvent-water partition coefficients or aqueous solubilities.

Productivity, sedimentation rate, and sedimentary organic matter in the oceans—I. Organic carbon preservation

Abstract: Comparison of rates of accumulation of organic carbon in surface marine sediments from the central North Pacific, the continental margins off northwest Africa, northwest and southwest America, the Argentine Basin, and the western Baltic Sea with primary production rates suggests that the fraction of primary produced organic carbon preserved in the sediments is universally related to the bulk sedimentation rate. Accordingly, less than 0.01% of the primary production becomes fossilized in slowly accumulating pelagic sediments [(2 to 6 mm (1000 y)−1] of the Central Pacific, 0.1 to 2% in moderately rapidly accumulating [2 to 13 cm (1000 y)−1] hemipelagic sediments off northwest Africa, northwest America (Oregon) and southeast America (Argentina), and 11 to 18% in rapidly accumulating [66 to 140 cm (1000 y)−1] hemipelagic sediments off southwest America (Peru) and in the Baltic Sea. The emiprical expression: % Org-C = 0.0030· R · S 0.30 p s (1−θ) implies that the sedimentary organic carbon content (% Org-C) doubles with each 10-fold increase in sedimentation rate (S), assuming that other factors remain constant; i.e., primary production (R), porosity (φ) and sediment density (ps). This expression also predicts the sedimentary organic carbon content from the primary production rate, sedimentation rate, dry density of solids, and their porosity; it may be used to estimate paleoproductivity as well. Applying this relationship to a sediment core from the continental rise off northwest Africa (Spanish Sahara) suggests that productivity there during interglacial oxygen isotope stages 1 and 5 was about the same as today but was higher by a factor of 2 to 3 during glacial stages 2, 3, and 6.

Effects of large organic material on channel form and fluvial processes

Abstract: \ SUMMARY Stream channel development in forested areas is profoundly influenced by large organic debris (logs, limbs and rootwads greater than 10 cm in diameter) in the channels. In low gradient meandering streams large organic debris enters the channel through bank erosion , mass wasting, blowdown, and collapse of trees due to ice loading. In small streams large organic debris may locally influence channel morphology and sediment transport processes because the stream may not have the competency to redistribute the debris. In larger streams flowing water may move large organic debris, concentrating it into distinct accumulations . (debris jams). Organic debris may greatly affect channel form and process by: increasing or decreasing stabilty of stream banks; influencing development of midchannel bars and short braided reaches; and faciltating, with other favourable circumstances, development of meander cutoffs. In steep gradient mountain streams organic debris may enter the channel by all the processes mentioned for low gradient streams. In addition, considerable debris may also enter the channel by way of debris avalanches or debris torrents. In small to intermediate size mountain streams with steep valley walls and little or no floodplain or flat valley floor, the effects of large organic debris on the fluvial processes and channel form may be very significant. Debris jams may locally accelerate or retard channel bed and bank erosion and/or deposition; create sites for significant sediment storage; and produce a stepped channel profile, herein referred to as ' organic stepping , which provides for variable channel morphology and flow conditions. The effed of live or dead trees anchored by rootwads into the stream bank may not only greatly retard bank erosion but also influence channel width and the development of small scour holes along the channel beneath tree roots. Once trees fall into the stream , their influence on the channel form and process may be quite different than when they were defending the banks , and, depending on thesize of the debris , size of the stream , and many other factors, their effects range from insignificant to very important.

Evergreen coniferous forests of the pacific northwest.

Abstract: The massive, evergreen coniferous forests in the Pacific Northwest are unique among temperate forest regions of the world. The region's forests escaped decimation during Pleistocene glaciation; they are now dominated by a few broadly distributed and well-adapted conifers that grow to large size and great age. Large trees with evergreen needle- or scale-like leaves have distinct advantages under the current climatic regime. Photosynthesis and nutrient uptake and storage are possible during the relatively warm, wet fall and winter months. High evaporative demand during the warm, dry summer reduces photosynthesis. Deciduous hardwoods are repeatedly at a disadvantage in competing with conifers in the regional climate. Their photosynthesis is predominantly limited to the growing season when evaporative demand is high and water is often limiting. Most nutrients needed are also less available at this time. The large size attained by conifers provides a buffer against environmental stress (especially for nutrients and moisture). The long duration between destructive fires and storms permits conifers to outgrow hardwoods with more limited stature and life spans.

Calcium oxalate accumulation and soil weathering in mats of the hypogeous fungus Hysterangium crassum

Abstract: Fungal mats of Hysterangium crassum (Tul. and Tul.) Fischer occupied a mean of 9.6% of the upper 10 cm of soil developed under a 40–65 yr old stand of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in Oregon. This hypogeous basidiomycete exudes large amounts of oxalic acid, some of which precipitates with Ca in microscopic crystals of calcium oxalate, resulting in a mean CaC2O4 content of 82g m−2 for the entire soil. Soil oxalate concentration was significantly greater within fungal mats (P

Gradual increase of oceanic CO2

Abstract: SINCE 1850, human activities, mainly the burning of fossil fuels and the clearing of forests, have increased the amount of CO2 in the atmosphere by ∼50 p.p.m.1–5. Although it is generally believed that the oceanic CO2 has increased correspondingly6–11, only very limited data12–14 have shown the increase quantitatively. We present here a computational calculation of the variation of the preformed total CO2 (ΣCO20) for a water mass, the original amount of total CO2 (ΣCO2) at the time of its last contact with the atmosphere. The result for the Atlantic Ocean reveals that the older water masses have invariably smaller ΣCO20 as compared to the more recently formed waters.

The contribution of stored water to transpiration in Scots pine

Abstract: . The amount of water available diurnally and annually from the storage tissues was measured in plots of Scots pine trees with four different population densities (608–3281 trees per ha) in a 40-year-old plantation in north eastern Scotland. The water storage capacity of stems, branches, and foliage was estimated from equations derived from harvested trees and measurements of relative water content. On average 64% of the water considered to be available for transpiration was in the stem sapwood and less than 5% in the phloem, cambium and foliage. Trees on the plot with the highest population density had a water storage capacity of 212 m3 ha−1 (21.2 mm), whereas those on the plot with the lowest population density had a water storage capacity of 124 m3 ha−1 (12.4 mm). The utilization of stored water in transpiration was estimated from seasonal and diurnal measurements of the relative water content of foliage and stem sapwood. The largest change in sapwood relative water content over a 2-week period was a reduction of 27% corresponding to extraction from the sapwood of 2.5 and 5.1 mm of water on the plots with the lowest and highest population densities, respectively. In rapidly changing weather conditions 1–1.5 mm day−1 could be removed from the stem sapwood alone. Since transpiration rarely exceeded 3 mm day−1, 30–50% of the transpired water was extracted from water stored in the stem sapwood over short periods. Trees on the plot with the lowest population density occasionally had slightly higher relative water contents and exhibited larger diurnal fluctuations than those on the plot with the highest population density, possibly because of differences in wood density. Sapwood water content was generally lower at times of high transpiration rate and in winter during freezing conditions. Resaturation took several months to complete during the winter.

Zonation and maintenance of copepod populations in the Oregon upwelling zone

Abstract: Oregon has one of the smaller and best known coastal upwelling systems. It is about 50 km wide, but upwelling is most intense within 15 km of the shore, and episodes of active upwelling primarily affect the circulation and hydrography of the upper 20 m. It is in this nearshore, surface zone that phytoplankton and zooplankton are most abundant. Phytoplankton biomass is 5 to 20 mg chl- a m −3 , and zooplankton 50 to 200 mg dry weight m −3 . Vertically stratified sampling along transects perpendicular to the shore has produced a new picture of the upwelling process and suggests relationships between circulation and the population biology of planktonic animals. The zooplankton is dominated by five species of copepod. Each is distributed in a different pattern: Acartia clausii is almost completely restricted to the upper 5 to 10 m of the water column and the first 5 km from shore. Pseudocalanus sp. is abundant from 0 to 15 km and between 10 and 20 m depth, but it reproduces only within a few kilometers of the shore. Acartia longiremis lives and reproduces offshore (10 km) in the surface (0 to 10-m) mixed layer. Oithona similis is abundant offshore (10 km) between 10- and 20-m depths. Calanus marshallae lives offshore as older copepodite stages, but the females return shoreward and lay their eggs at about 10 km offshore. The nauplii and younger copepodites develop in the very nearshore zone. The patterns of animal distribution together with data on salinity, temperature, and chlorophyll- a lead to the following conclusions about the circulation in the Oregon upwelling zone: First, during active upwelling, the Ekman layer within 0 to 10 km is less than 5 m deep. Offshore of the frontal region, this layer is 10 to 15 m thick. Second, when upwelling is active, the surface layer offshore of the frontal region is not continuously transported offshore. Instead, this mass is moved offshore some fixed distance, no more than 20 to 40 km. During relaxation, this surface water returns shoreward to its former location. Third, we propose a two-cell zonal circulation scheme during initiation of active upwelling: Looking north in vertical section, a divergence is located 10 km from shore, with a clockwise rotating cell on the landward side and a counterclockwise cell on the seaward side. The population of each zooplankton species appears to be maintained within the upwelling zone by a specific relationship between its distribution and the circulation.

Circular dichroism and DNA secondary structure

Abstract: The change in average rotation of the DNA helix has been determined for the transfer from 0.05 M NaCl to 3.0 M CsCl, 6.2 M LiCl and 5.4 M NH4Cl. This work, combined with data at lower salt from other laboratories, allows us to relate the intensity of the CD of DNA at 275 nm directly to the change in the number of base pairs per turn. The change in secondary structure for the transfer of DNA from 0.05 M NaCl (where it is presumably in the B-form) to high salt (where the characteristic CD has been interpreted as corresponding to C-form geometry) is found to be -0.22 (+/- 0.02) base pairs per turn. In the case of mononucleosomes, where the CD indicates the "C-form", the change in secondary structure (including temperature effects) would add -0.31 (+/- 0.03) turns about the histone core to the -1.25 turns estimated from work on SV40 chromatin. Accurate winding angles and molar extinction coefficients were determined for ethidium.

Sinking rates of natural copepod fecal pellets

Abstract: Many pure samples of natural fecal pellets have been collected from mixed small copepods and from the pontellid copepod Anomalocera patersoni in the Ligurian Sea, using a specially designed pellet collection device. Sinking rates of fresh pellets and pellets aged up to 33 days have been determined at 14°C, the mean temperature of the essentially isothermal water column in the Ligurian Sea. Sinking rates of pellets collected during calm sea states increased with increasing pellet volume, but sinking rates of pellets collected during rough sea (Beaufort scale ≃6) showed little correlation with pellet size. Much of the variability in the sinking rate-pellet size relationships was the result of different pellet composition and compaction, but not pellet age. Pellets produced from laboratory diets of phytoplankton and phytoplankton-sediment mixes showed the expected wide variability in sinking rates, with sediment-ballasted pellets sinking much faster than pellets produced from pure algal diets; thus determination of vertical material fluxes in the sea using laboratory-derived fecal pellet sinking rates is unwarranted. Natural pellet sinking data for small copepods and A. patersoni have been combined with similar data for euphausiids, to yield sinking rates of roughly two orders of magnitude over three orders of magnitude in pellet volume. Pellets from small copepods sank at speeds too slow to be of much consequence to rapid material flux to the deep sea, but they undoubtedly help determine upper water distribution of materials. Recalculation of fecal pellet mass flux estimates from the literature, using our sinking rate data for natural small copepod pellets, yielded estimates about half those of previously published values. Earlier studies had concluded that small fecal pellets were of lesser significance to total material flux than fecal matter; our recalculation strengthens that conclusion. Pellets from large copepods and euphausiids, however, have the capability to transport materials to great depths, and probably do not substantially recycle materials near the surface. The fact that the majority of pellets which had previously been collected in deep traps by other workers were of a size comparable to pellets from our large copepods supports the contention that these larger pellets are the main ones involved in vertical flux.

Hydrogenase in Rhizobium japonicum Increases Nitrogen Fixation by Nodulated Soybeans

Abstract: Some Rhizobium strains synthesize a unidirectional hydrogenase system in legume nodule bacteroids; this system participates in the recycling of hydrogen that otherwise would be lost as a by-product of the nitrogen fixation process. Soybeans inoculated with Rhizobium japonicum strains that synthesized the hydrogenase system fixed significantly more nitrogen and produced greater yields than plants inoculated with strains lacking hydrogen-uptake capacity. Rhizobium strains used as inocula for legumes should have the capability to synthesize the hydrogenase system as one of their desirable characteristics.

A Suggestion for the Presentation of Correlations and Their Significance Levels

Abstract: It is suggested that the results of correlation calculations between concurrent time series be presented in the form of normalized correlations, the normalization factor being the estimated large-lag standard error. This factor is easily estimated from the data using the Bartlett formula and reflects the interplay of the dominant time scales of the input processes and the finite record length. It is shown that significance levels are inherent in the normalized correlations and the procedure used to obtain them is mathematically equivalent to that now widely used in oceanography.

An observational study of the structure of the nocturnal boundary layer

Abstract: In an effort to describe the basic vertical structure of the nocturnal boundary layer, observations from four experiments are analyzed. During the night, the depth of significant cooling appears to increase with time while the depth of the turbulence and height of the low level wind maximum tend to remain constant or decrease with time. Since the inversion layer extends above the low level wind maximum and shear is small in the region of the low level jet, the Richardson number reaches a maximum at the jet level and then decreases again with height. As a result, turbulence is observed to be a minimum at the height of the low level wind maximum and then increases again above this height.

Hydrogen-Dependent Nitrogenase Activity and ATP Formation in Rhizobium japonicum Bacteroids

Abstract: Rhizobium japonicum 122 DES bacteroids from soybean nodules possess an active H2-oxidizing system that recycles all of the H2 lost through nitrogenase-dependent H2 evolution The addition of 72 μM H2 to suspensions of bacteroids increased O2 uptake 300% and the rate of C2H2 reduction 300 to 500% The optimal partial pressure of O2 was increased, and the partial pressure of O2 range for C2H2 reduction was extended by adding H2 A supply of succinate to bacteroids resulted in effects similar to those obtained by adding H2 Both H2 and succinate provided respiratory protection for the N2-fixing system in bacteroids The oxidation of H2 by bacteroids increased the steady-state pool of ATP by 20 to 40% In the presence of 50 mM iodoacetate, which caused much greater inhibition of endogenous respiration than of H2 oxidation, the addition of H2 increased the steady-state pool of ATP in bacteroids by 500% Inhibitor evidence and an absolute requirement for O2 indicated that the H2-stimulated ATP synthesis occurred through oxidative phosphorylation In the presence of 50 mM iodoacetate, H2-dependent ATP synthesis occurred at a rate sufficient to support nitrogenase activity The addition of H2 to H2 uptake-negative strains of R japonicum had no effect on ATP formation or C2H2 reduction It is concluded that the H2-oxidizing system in H2 uptake-positive bacteroids benefits the N2-fixing process by providing respiratory protection of the O2-labile nitrogenase proteins and generating ATP to support maximal rates of C2H2 reduction by oxidation of the H2 produced from the nitrogenase system

Causative factors of color deterioration in strawberry preserves during processing and storage

Abstract: Factors responsible for the differences in color quality between preserves commercially manufactured from Hood and Tioga strawberry varieties were determined. Color analyses on Hood and Tioga preserves during a 26-wk storage period revealed that color deterioration occurred at a much faster rate in Tioga preserves than in Hood preserves, and that this deterioration was due to a faster rate of browning. Compositional analyses of fruit showed that the Tioga variety contained higher levels of leucoanthocyanins, flavanols and total phenolics while the Hood variety contained higher levels of anthocyanin pigment, ascorbic acid, and free amino acids. It is proposed that reactive phenolics (leucoanthocyanins, flavanols) play a major role in the color deterioration of strawberry preserves.

Failure of antiplatelet and anticoagulant therapy to improve patency of grafts after coronary-artery bypass: a controlled, randomized study.

Abstract: Fifty patients who underwent aortocoronary saphenous-vein bypass-graft surgery were randomly assigned to one of three groups to determine the effects of antiplatelet or anticoagulant therapy on graft patency. Twenty-four patients served as controls; 13 patients received aspirin (325 mg three times a day) and dipyridamole (75 mg three times a day); and 13 patients received closely regulated warfarin therapy. Medications were begun on the third post-operative day. Six months after surgery, all patients underwent coronary angiography to assess graft patency. There were no statistically significant differences between groups in various clinical, hemodynamic and angios, 27 of 33 grafts (82 per cent) with aspirin and dipyridamole and 29 of 37 grafts (78 per cent) with warfarin (P less than 0.5), all patients had at least one patent graft. Postoperative treatment either with aspirin and dipyridamole or with warfarin failed to improve the patency of the grafts.

Food selection capabilities of the estuarine copepod Acartia clausi

Abstract: Existing viewpoints and theories of selective grazing by copepods are briefly reviewed in order to formulate explicit hypotheses to be tested experimentally. Based on these hypotheses, a series of grazing experiments was run to determine (1) the extent of the selective ingestion capabilities of Acartia clausi and (2) how these capabilities were affected by previous feeding histories. Groups of copepods were separately preconditioned on a small diatom (Thalassiosira pseudonana), a large diatom (T. fluviatilis), or a plastic sphere. The ingestive behavior was then examined on various combinations of spheres and food particles. Spheres offered alone were not ingested. In mixtures of diatoms and spheres, the copepods avoided ingesting spheres intermediate in size between the sizes of the diatoms. The copepods either ingested particles on either side of the spheres, or ignored all particles less than the size of the largest spheres. The pattern observed depended upon the size of the preconditioning food. However, if the spheres were larger than the largest food particles, the copepods still selectively ingested the food particles. The above results demonstrate that A. clausi has a complex grazing behavior consisting of (1) more efficient grazing on larger particles within its particle-size ingestion range; (2) the ability to alter “effective” setal spacing to optimize feeding behavior (i.e., the ability to increase efficiency of capture of food particles, and to avoid non-food particles); and (3) the ability for post-capture rejection of non-food particles when they interfere with the ingestion of food particles on which the copepod has been preconditioned. The behavioral patterns observed depend heavily on the food preconditioning and the presence or absence of non-food particles. These results clearly indicate that a simple “mechanistic” explanation of selective grazing is insufficient.

Prediction of Convective Mixed-Layer Entrainment for Realistic Capping Inversion Structure

Abstract: The first-order jump model for the potential temperature or buoyancy variable at the capping inversion atop a convectively mixed layer is reexamined and found to imply existence of an entrainment rate equation which is unreliable. The model is therefore extended here to allow all the negative buoyancy flux of entrainment to occur within the interfacial layer of thickness Δh and to allow realistic thermal structure within the layer. The new model yields a well behaved entrainment rate equation requiring scarcely any closure assumption in the cases of steady-state entrainment with large-scale subsidence, and pseudo-encroachment. For nonsteady entrainment the closure assumption need only be made on d(Δh)/dt in order to obtain the entrainment rates at both the outer and inner edges of the interfacial layer. A particular closure assumption for d(Δh)/dt is tested against five laboratory experiments and found to yield favorable results for both Δh and the mixed-layer thickness if the initial value of Δh...

Conformation and circular dichroism of DNA

Abstract: CD spectra of calf thymus, C. perfringens, E. coli, and M. luteus DNA have been measured in the vacuum-uv region to about 168 nm for the A-, B-, and C-forms. The positive band at about 187 nm and the negative band at about 170 nm found for each type and form of DNA are sensitive to the source of the DNA and the base–base interactions of the double-stranded helix. The A-form spectra confirm that these bands are indeed sensitive to secondary structure. In the near-uv, the CD of B-form DNA is well analyzed as a linear combination of 27% A-form and 78% C-form. However, an analysis of the extended spectrum demonstrates that the near-uv analysis is not correct. The extended analysis shows that the base–base interactions are similar for B- and C-forms in solution, which implies that these two forms have nearly the same number of base pairs per turn. Various types of CD difference spectra are also discussed.

The turbulent heat flux from arctic leads

Abstract: The turbulent transfer of heat from Arctic leads in winter is one of the largest terms in the Arctic heat budget. Results from the AIDJEX Lead Experiment (ALEX) suggest that the sensible component of this turbulent heat flux can be predicted from bulk quantities. Both the exponential relation N = 0.14R x 0.72 and the linear relation N = 1.6 × 10−3 R x+ 1400 fit our data well. In these, N is the Nusselt number formed with the integrated surface heat flux, and R x is the Reynolds number based on fetch across the lead. Because of the similarity between heat and moisture transfer, these equations also predict the latent heat flux. Over leads in winter, the sensible heat flux is two to four times larger than the latent heat flux. The internal boundary layer (IBL) that develops when cold air encounters the relatively warm lead is most evident in the modified downwind temperature profiles. The height of this boundary layer, δ, depends on the fetch, x, on the surface roughness of the lead, z 0 and on both downwind and upwind stability. A tentative, empirical model for boundary layer growth is % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4baFfea0dXde9vqpa0lb9% cq0dXdb9IqFHe9FjuP0-iq0dXdbba9pe0lb9hs0dXda91qaq-xfr-x% fj-hmeGabaqaciGacaGaaeqabaWaaeaaeaaakeaadaWcaaqaaiabes% 7aKbqaaiaadQhadaWgaaWcbaGaaGimaaqabaaaaOGaeyypa0JaeqOS% di2aaeWaaeaacqGHsisldaWcaaqaaiaadQhadaWgaaWcbaGaaGimaa% qabaaakeaacaWGmbaaaaGaayjkaiaawMcaamaaCaaaleqabaGaaGim% aiaac6cacaaI4aaaaOWaaeWaaeaadaWcaaqaaiaadIhaaeaacaWG6b% WaaSbaaSqaaiaaicdaaeqaaaaaaOGaayjkaiaawMcaamaaCaaaleqa% baGaaGimaiaac6cacaaI0aaaaaaa!472D!\[\frac{\delta }{{z_0 }} = \beta \left( { - \frac{{z_0 }}{L}} \right)^{0.8} \left( {\frac{x}{{z_0 }}} \right)^{0.4} \] where L is the Obukhov length based on the values of the momentum and sensible heat fluxes at the surface of the lead, and Β is a constant reflecting upwind stability. Velocity profiles over leads are also affected by the surface nonhomogeneity. Besides being warmer than the upwind ice, the surface of the lead is usually somewhat rougher. The velocity profiles therefore tend to decelerate near the surface, accelerate in the mid-region of the IBL because of the intense mixing driven by the upward heat flux, and rejoin the upwind profiles above the boundary layer. The profiles thus have distinctly different shapes for stable and unstable upwind conditions.