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The purpose of this study was to determine if occupants' satisfaction and problems with their houses differed by four categories of passive solar systems. The four categories were: 1) south facing window, ...
Citation Citation
- Title:
- Occupants' satisfaction and problems among four categories of passive solar systems
- Author:
- Malroutu, Yamini Lakshmi
The purpose of this study was to determine if occupants' satisfaction and problems with their houses differed by four categories of passive solar systems. The four categories were: 1) south facing window, 2) sunspace, 3) south facing window + sunspace, and 4) south facing window + sunspace + Trombe wall. The objectives were: 1) to determine if occupants' satisfaction with 12 features of their houses differed by four categories of passive solar systems, 2) to determine if the occupants' overall satisfaction with features of their houses differed by four categories of passive solar systems, 3) to assess if there were differences in occupants' reported occurrence of 18 problems among the four categories of passive solar systems, and 4) to assess if occupants' overall problem differed among the four categories of passive solar systems. The data were collected in a mail survey, Passive Solar Homes in Oregon, in 1986. The sample size for this study consisted of 273 passive solar houses in Oregon. Statistical analyses of the data were computed using frequency distributions, Chi-square tests, and one-way analysis of variance. The majority of the respondents in this study were young, around 45 years, lived in small households, were college educated, and owned their houses. Their mean gross family income was in the category of $ 40,000 through $ 49,999. The majority of the houses in this sample were single family detached built on one to two acres of land. The median size of the houses was in the category of 1,500 through 1,999 square feet, and they were located outside the city limits. The category of passive solar system used most in the design of the houses was the south facing window + sunspace system. The majority of the respondents were very satisfied with the following features of their houses: time and effort required in daily operation, exterior design of house, floor plan, interior decorating and general maintenance requirements. The problem of cleaning of high window or glass areas was reported by most respondents. There was a significant (p <̲ .05) difference in occupants' satisfaction with the general maintenance requirements (p = .008) among the four categories of passive solar houses. There was no difference (p <̲ .05) in occupants' satisfaction with 1) energy savings, 2) heat distribution, 3) cooling distribution, 4) humidity control, 5) exterior design of house, 6) comfort level, 7) effort and time required in daily operation, 8) performance of mechanical components, 9) floor plan, 10) internal noise level, and 11) interior decorating among the four categories of passive solar systems. There was no significant (p <̲ .05) difference in occupants' overall satisfaction among the four categories of passive solar systems. There was a significant (p <̲ .075) difference in occupants' reported occurrence with three problems: 1) high noise levels (p=.072), 2) inadequate weatherstripping or caulking (p=.058), and 3) coverings for sloped windows (p=.033) among the four categories of passive solar systems. There was no difference (p <̲ .075) in occupants' reported occurrence of 1) excessive glare, 2) excessive humidity, 3) condensation on windows, 4) extreme temperature swings, 5) nonresiliency of floors, 6) not warm enough, 7) excessive heat loss through aluminum windows, 8) inadequate shading of deciduous trees, 9) manual use of movable window insulation, 10) inadequate movement of heat, 11) high windows or other glass areas cleaned, 12) fading of furniture, walls, or coverings, 13) lack of privacy, 14) excessive drafts, and 15) rooms cool down too fast among the four categories of passive solar systems. Occupants also did not differ (p <̲ .075) in their overall problem among the four categories of passive solar systems. The findings of this research will be of use and interest to future consumers of passive solar houses and housing professionals involved with passive solar energy. Educators and researchers concerned with solar energy and policy makers dealing with energy issues will also benefit from the study.
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Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological ...
Citation Citation
- Title:
- Double-crested Cormorants (Phalacrocorax auritus) and Brandt’s Cormorants (P. penicillatus) Breeding at East Sand Island in the Columbia River Estuary : Foraging Ecology, Colony Connectivity, and Overwinter Dispersal
- Author:
- Peck-Richardson, Adam
Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological theory predicts that such morphologically similar species will partition prey resources when faced with resource limitations. During the summer of 2014, I investigated local movements, foraging dive behavior, and foraging habitat selection by breeding adults of both cormorant species using GPS tags with integrated temperature and depth data-loggers (GPS-TDlog, Earth & Ocean Technologies). The overall foraging areas and core foraging areas (defined as the 95% and 50% kernel density estimates of dive locations, respectively) of double-crested cormorants were much larger and covered a broader range of estuarine habitats than those of Brandt’s cormorants. Only 26% and 27% of the overall and core foraging areas, respectively, for double-crested cormorants overlapped with those of Brandt’s cormorants. Most of the overall and core foraging areas of Brandt’s cormorants (59% and 89%, respectively) overlapped with those of double-crested cormorants, however. Within areas of overlap, Brandt’s cormorants tended to dive deeper (median depth = 6.48 m) than double-crested cormorants (median depth = 2.67 m), and selected dive locations where the water was deeper. After accounting for local water depth, Brandt’s cormorants utilized a deeper, more benthic portion of the water column than did double-crested cormorants. Our results indicate that species-specific patterns of foraging habitat utilization likely reflect past evolutionary divergence in foraging niche and evolved differences in behavioral and physiological adaptations, resulting in some partitioning of prey resources that would mitigate interspecific competition. Nevertheless, the substantial overlap in foraging habitat between the two cormorant species, particularly for Brandt’s cormorants, suggests that superabundant prey resources allow these two large and productive cormorant colonies to coexist on a single island near the mouth of the Columbia River. Annual consumption of millions of out-migrating juvenile salmonids (Oncorhynchus spp.), including smolts from populations listed under the U.S. Endangered Species Act, by double-crested cormorants nesting at ESI motivated natural resource managers to investigate potential management techniques to reduce cormorant predation by reducing the size of the breeding colony. To better understand potential dispersal of cormorants from the ESI colony due to management to reduce colony size, satellite transmitters were fitted on 83 double-crested cormorants captured on the ESI colony before egg-laying in 2013. Dispersal from ESI immediately following tagging was nearly ubiquitous, but temporary, and provided limited information on where cormorants might prospect for alternative nest sites if prevented from nesting on ESI. During this initial pre-nesting period, tagged cormorants were detected at colonies and roost sites as far from ESI as the Puget Sound region of coastal Washington; nevertheless, all but 4% of tagged cormorants returned to ESI within 2 weeks of being tagged. Following the subsequent breeding season, tagged cormorants staged at several nearby estuaries before migrating both north and south from ESI to overwinter in areas from British Columbia to northwestern Mexico; only 3% overwintered in the Columbia River estuary. Tracking data revealed substantial connectivity between the ESI colony and other colonies and regions within the range of the western North America population, suggesting the potential for widespread dispersal throughout the population’s breeding range if nesting habitat on ESI was reduced or eliminated. Dispersal did not extend across the Cascade-Sierra Divide, however; greater connectivity existed with estuary locations throughout the range and particularly with more proximate estuaries that served as post-breeding staging areas. Surprisingly low regional and colony connectivity was observed with the Oregon Coast, despite numerous active and historical colonies in that region, as well as proximity to the colony at ESI. The strong philopatry to ESI that nearly all tagged cormorants exhibited, however, suggests that few alternative nesting opportunities are as attractive for prospecting double-crested cormorants as the ESI colony site.
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4943. [Article] The ecology and production dynamics of four black fly species (Diptera:simuliidae) in western Oregon streams
Ecological and production studies of Prosimulium caudatum Shewell, P. dicum Dyar and Shannon, Simulium arcticum Malloch and S. canadense Hearle (Diptera: Simuliidae) were made in 1971 and 1972 in three ...Citation Citation
- Title:
- The ecology and production dynamics of four black fly species (Diptera:simuliidae) in western Oregon streams
- Author:
- Speir, Jon A.
Ecological and production studies of Prosimulium caudatum Shewell, P. dicum Dyar and Shannon, Simulium arcticum Malloch and S. canadense Hearle (Diptera: Simuliidae) were made in 1971 and 1972 in three streams near Corvallis, Oregon. The purpose of the study was to characterize the biology and population dynamics of larvae, and to compare the production of the four species under various spatial and temporal conditions. A total of 54 annual production estimates was derived utilizing 37 stations. In addition, 17 annual drift and 22 emergence (as pupae) determinations were made. Data on the physical and chemical characteristics of the streams, and on larval associates, parasites, predators and food types were obtained at all stations. Laboratory experiments provided data on feeding rates and predator impact. The two Prosimulium species always coexisted, and occurred in all streams. Simulium arcticum and S. canadense were studied in two streams only. All species were univoltine and had egg stage durations exceeding 40 weeks. Prosimulium spp. larvae appeared in mid-February and were on riffles for an average of 10.3 weeks. Simulium arcticum hatching began about six weeks later. Larvae of this species developed in an average of 8.8 weeks. Development of S. canadense began about nine weeks later than for Prosimulium spp. but lasted nearly as long. All four black flies had six larval instars. All larvae were filter feeders, and fed primarily on the suspended materials in the streams. Detritus made up from 65-90% of the diet, with the rest being filamentous algae. Alimentary tract clearing of larvae was usually accomplished in less than one hour. Black fly immatures were associated with about 75 other benthic insect species. Of these, nine were likely important simuliid natural enemies. Fish were minor black fly predators. Gastromermis nematodes occurred in about 3% of all mature simuliid larvae. Annual losses due to drift averaged about 6%. Simuliid drift appeared to be a function of standing crop density. Growth-related crowding may also have been a factor. Effects of diel light conditions, temperature and discharge were minimal. A diel emergence pattern existed for Simulium spp. adults only. The time between emergence and oviposition was likely about 0.5 week for all species. Emergence at most stations was single peaked, and averaged 3. 6 weeks in duration. The sampling universe at each station could be effectively partitioned to exclude areas where larvae did not exist. Thus, the weekly stratified random sampling program provided population estimates with error terms of usually 15% or less. All quantitative data were expressed on a per m² of overall riffle basis (and not on a per m² of habitat basis) to make the study more comparable to other benthic research. Density, biomass and production differences between stations, streams and years were minimal for each species, and therefore were treated as replicates. Initial densities ranged from over 11000 to about 16000 larvae/m². Mortality for aggregates of all species was similar, with about 70% of all losses occurring during the first half of larval life. Growth for all species was generally logistic and averaged over 0.090 gig per day annually. Production, averaged for 1971 and 1972, in g/m² , was: P. caudatum, 2.644; P. dicum, 2.908; S. canadense, 3. 141; and S. arcticum, 3.950. This species ranking also held for initial density, mean density and mean biomass. Biomass and production were almost always closely correlated. Mortality variations had a greater influence on production than did growth rate. Averaged for all species, the mean total mortality due to drift and parasites was 6.2% and 0.5% respectively. An average of 10.7% of colonizing larvae survived to emerge. Predator-caused losses were estimated to provide the 82.6% needed to balance the loss budget. Black fly larvae were the dominant processor of suspended materials in the three streams. On the average, they outnumbered all other primary consumers combined on riffles by a factor of 27. Simuliid larvae functioned as the primary prey reservoir for as many as 20 species of insect carnivores from February through June of both years.
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4944. [Article] Structural and volcanic evolution of the Glass Buttes area, High Lava Plains, Oregon
The Glass Buttes volcanic complex is a cluster of bimodal (basalt-rhyolite), Miocene to Pleistocene age lava flows and domes located in Oregon's High Lava Plains province, a broad region of Cenozoic bimodal ...Citation Citation
- Title:
- Structural and volcanic evolution of the Glass Buttes area, High Lava Plains, Oregon
- Author:
- Boschmann, Darrick E.
The Glass Buttes volcanic complex is a cluster of bimodal (basalt-rhyolite), Miocene to Pleistocene age lava flows and domes located in Oregon's High Lava Plains province, a broad region of Cenozoic bimodal volcanism in south-central Oregon. The High Lava Plains is deformed by northwest-striking faults of the Brothers Fault Zone, a diffuse, ~N40°W trending zone of en echelon faults cutting ~250 km obliquely across the High Lava Plains. Individual fault segments within the Brothers Fault Zone are typically <20 km long, strike ~N40°W, have apparent normal separation with 10-100 m throw. A smaller population of ~5-10 km long faults striking ~N30°E exhibits mutually crosscutting relationships with the dominant northwest striking faults. Basaltic volcanic rocks in the Glass Buttes area erupted during the late Miocene and Pleistocene. The oldest and youngest lavas are 6.49±0.03 Ma and 1.39±0.18 Ma, respectively, based on ⁴⁰Ar/³⁹Ar ages of five basaltic units. Numerous small mafic vents both within and around the margins of the main silicic dome complex are commonly localized along northwest-striking faults of the Brothers Fault Zone. These vents erupted a diverse suite of basalt to basaltic andesite lava flows that are here differentiated into 15 stratigraphic units based on hand sample texture and mineralogy as well as major and trace element geochemistry. The structural fabric of the Glass Buttes area is dominated by small displacement, discontinuous, en echelon, northwest-striking fault scarps that result from normal to slightly oblique displacements and are commonly linked by relay ramps. Northwest alignment of basaltic and rhyolitic vents, paleotopography, and cross-cutting relationships suggest these faults have been active since at least 6.49±0.03 Ma, the age of the rhyolite lavas in the eastern Glass Buttes are. Faults displace Quaternary sedimentary deposits indicating these structures continue to be active into the Quaternary. Long-term extension rates across northwest-striking faults calculated from 2-5 km long cross section restorations range from 0.004 – 0.02 mm/yr with an average of 0.12 mm/yr. A subordinate population of discontinuous northeast-striking faults form scarps and exhibit mutually cross-cutting relationships with the dominant northwest-striking population. Cross-cutting relationships indicate faulting on northeast-striking faults ceased sometime between 4.70±0.27 Ma and 1.39±0.18 Ma. Gravity data at Glass Buttes reveals prominent northwest- and northeast-trending gravity gradients that closely parallel the strikes of surface faults. These are interpreted as large, deep-seated, normal faults that express themselves in the young basalts at the surface as the discontinuous, en echelon fault segments seen throughout the study area and BFZ in general. Elevated geothermal gradients are localized along these deep-seated structures at two locations: (1) where northwest- and northeast-striking faults intersect,(2) along a very prominent northwest-striking active normal fault bounding the southwest flank of Glass Butte. High average heat flow and elevated average geothermal gradients across the High Lava Plains, and the presence of hydrothermal alteration motivated geothermal resource exploration at Glass Buttes. Temperature gradient drilling by Phillips Petroleum and others between 1977-1981 to depths of up to 600 m defined a local geothermal anomaly underlying the Glass Buttes volcanic complex with a maximum gradient of 224 °C/km. Stratigraphic constraints indicate that near-surface hydrothermal alteration associated with mercury ores ceased before 4.70±0.27 Ma, and is likely associated with the 6.49±0.03 Ma rhyolite eruptions in the eastern part of Glass Buttes. The modern thermal anomaly is not directly related to the pre-4.70±0.27 Ma hydrothermal system; rather it is likely a result of deep fluid circulation along major extensional faults in the area.
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The western United States is experiencing significant changes in wildfire and snow regimes as a result of warming temperatures. An amplification of wildfire activity and reduction in snow water equivalent, ...
Citation Citation
- Title:
- Post-fire vegetation response to snow in the western United States
- Author:
- Blauvelt, Katie
The western United States is experiencing significant changes in wildfire and snow regimes as a result of warming temperatures. An amplification of wildfire activity and reduction in snow water equivalent, snow covered area, and earlier spring snowmelt are documented trends that are projected to continue into the future. With an increase in wildfire activity, it is important to understand how a reduction in snow will impact regenerating vegetation in the western United States. The first objective of this study was to assess summer vegetation biomass response to antecedent winter snow on a local scale by determining the physiographic characteristics that influence the relationship between snow and vegetation in the case of the 2002 Biscuit Fire. The second objective was to assess the broad scale regional patterns of regenerating vegetation response to snow, by comparing the correlation between summer vegetation biomass and antecedent winter snow before and after large wildfires across the western United States. Remote sensing data and spatial-temporal statistics were used to analyze the relationship between snow and vegetation. In the local scale analysis, the 2002 Biscuit Fire was analyzed, which burned over 2,000 km² in southwest Oregon and northern California. Nonparametric Multiplicative Regression (NPMR) was used to explore the complex relationships between multiple predictor variables (winter snow frequency, elevation, slope, aspect, and burn severity) and the summer vegetation response variable (enhanced vegetation index, or EVI), before and after the Biscuit Fire burned. The burned area was subset by soil type to determine how soil texture influenced the snow and vegetation relationship. In the regional scale analysis, the Pearson's Correlation Coefficient was calculated to analyze the relationship between winter snow frequency and summer EVI before and after 23 wildfires across the western United States. In the case of the Biscuit Fire, summer EVI responded negatively to snow before the fire, and responded positively to snow after the fire. EVI in coarse-textured skeletal soils exhibited the clearest shift to a positive response to snow after the fire burned, while EVI in fine-textured clay soils did not exhibit this type of shift. The regional analysis proved that wildfire disturbances affect the relationship between snow and vegetation differently across the western United States. Seven fires clustered near the Biscuit Fire in northern California and southwestern Oregon behaved similar to the Biscuit Fire, shifting from a negative pre-fire snow and EVI correlation to a less negative or positive post-fire snow and EVI correlation. The majority of these fires had relatively low average elevations (430 to 1708 m) with greater than 80% forest land cover. Ten fire areas exhibited a significant positive pre and post-fire snow and EVI correlation. The majority of these fires had relatively high average elevations (1612 to 2291 m) and consisted of greater than 50% shrub, scrub, and grass land cover. The local scale analysis suggests that the condition of the vegetation (undisturbed vs. regenerating) and the soil texture in which it grows affects its response to winter snow. The low water holding capacity of coarse-textured soils and the short root-lengths of regenerating vegetation may result in greater dependence on snow as a water resource. Regionally, vegetation type and elevation may affect the vegetation's response to snow; short-rooted shrubs at higher elevations above the transient snow zone may be more dependent on snow as a water resource. These results suggest that the relationship between snow and vegetation is not constant, depending on the condition of the vegetation. Increases in wildfire activity and a reduction of snow in the future may impact successional trajectories in certain regions where vegetation may have historically relied on snowmelt to regenerate.
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4946. [Article] The influence of environment and pathogen variability on the infection of wheat by Puccinia striiformis West
Race identification of stripe rust (Puccinia striiformis West. ) is influenced by environment, pathogen variability and host age. Isolates of stripe rust were collected in the Pacific Northwest and characterized ...Citation Citation
- Title:
- The influence of environment and pathogen variability on the infection of wheat by Puccinia striiformis West
- Author:
- Beaver, Richard Gary, 1939-
Race identification of stripe rust (Puccinia striiformis West. ) is influenced by environment, pathogen variability and host age. Isolates of stripe rust were collected in the Pacific Northwest and characterized on two sets of differential varieties; the "Oregon" and the United States. Six of the seven isolates tested on the seedling Oregon differentials were identified as separate races at the 2 C/18 C (night /day) temperature profile; however, seven races could be identified using mature plants. Eight of the 16 Oregon differentials used as seedlings gave similar infection types as mature plants with all seven isolates tested. The remaining eight varieties changed from a susceptible seedling reaction to a more resistant reaction as a mature plant with specific host-pathogen combinations. This change can be used to separate the seven isolates into races. Only the variety Leda was consistently more resistant as a mature plant than as a seedling. This "mature plant resistance" is contrasted to the "field resistance" of the variety Gaines which is conditioned by environment. Five of the eight isolates tested on the United States differential varieties could be identified as separate races. With the aid of the eight supplemental varieties all eight isolates could be separated. Six field races of stripe rust could be identified on wheat grown at 11 sites in Oregon using the Oregon field differential varieties. These varieties also indicated a shift in the make-up of the rust race populations during the last four years in the Willamette Valley. Similarities in field race characteristics at Pendleton, in eastern Oregon, and Aurora, in the Willamette Valley, were also noted. Percentage of germination and penetration of uredospores of stripe rust differed on 15 Oregon differential varieties. An unidentified factor inhibited uredospore germination on certain varieties. Penetration of stomates was also delayed on some varieties but no consistent correlation could be made with inhibition of germination or host resistance to stripe rust. Desiccation following short dew periods of three or four hours effectively reduced the amount of viable inoculum available during a 24-hour period. Inoculum removal by desiccation can be made more effective by the use of varieties that lengthen the interval from uredospore germination to penetration. Under field conditions, inoculum removal can reduce final disease severity. For example, with an apparent infection rate of 0.0146 per unit per day for stripe rust, removal of inoculum from death of germinating spores for a five day period would reduce the final disease severity by 14.7 percent over a 40-day period. Factors limiting fall spread of stripe rust in the Willamette Valley differ from those in eastern Oregon. In the Willamette Valley spore movement is by leaf to leaf contact during the wet winter months. In eastern Oregon little or no rust movement occurs until warm spring weather facilitates aerial spore movement. During most years sporulating leaves are killed by freezing winter weather and rust survival is limited to infected, non-sporulating green host tissue. Competition for infection and sporulation sites between an albino race of stripe rust and four yellow races was noted. Some mechanism inherent to the albino race and presumably other races prevents invasion and/or sporulation within previously colonized host tissue. Competition between two races of stripe rust can reduce the potential number of sites for infection on a wheat leaf by 99 percent. In addition, competition can change the ratio of one race to another in the population from 1:1 to 3:1 in one generation. Summer survival on grasses in mountain areas of Oregon is limited and does not appear to play an important role in oversummering of stripe rust in Oregon. Field race(s) of stripe rust found at the Mountain Plots appears similar to race(s) in wheat growing areas. Movement of inoculum from mountain areas to wheat fields in the fall of the year seems unlikely since rust on wheat and grasses inoculated in June could not be found the following September.
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Inflammation is the body's response to injury and is characterized by pain, swelling, redness, and heat. Eicosanoids are lipid mediators of inflammation. Leukotrienes (LT) are 20-carbon eicosanoids produced ...
Citation Citation
- Title:
- Dietary polyunsaturated fatty acids and leukotriene production in poultry
- Author:
- Jha, Shantibhushan
Inflammation is the body's response to injury and is characterized by pain, swelling, redness, and heat. Eicosanoids are lipid mediators of inflammation. Leukotrienes (LT) are 20-carbon eicosanoids produced from arachidonic acid (AA), an n-6 fatty acid (FA), and eicosapentaenoic acid (EPA), an n-3 FA. LT produced from AA are proinflammatory (LTB₄) and those produced from EPA (LTB₅) are less inflammatory. Two experiments were conducted. The objective of the first experiment was to optimize the assay conditions for LT production by platelets from chickens, and neutrophils from horses and dogs. Optimal production of LT from equine and canine neutrophils and chicken platelets was characterized in terms of incubation time (2.5, 5, 10, 15 or 20 minutes), temperature (25 or 37°C), and calcium ionophore A23187 concentration (0.1, 1, 10 or 20 μM). In all species, incubation at 37°C resulted in optimal LTB₄ production compared to 25°C (p≤0.05). Production of LTB₄ was maximum when neutrophils were stimulated with 20 μM calcium ionophore A23187 in all species (p≤0.05). Incubation times greater than 2.5 minutes did not further increase LTB₄ production in chickens and horses; in dogs, incubation for 2.5 and 10 minutes resulted in the highest concentrations of LTB₄ (p≤0.05). These results indicate that platelets from chickens, and neutrophils from horses and dogs, are capable of producing LTB₄; optimum conditions for LTB₄ production are similar in all three species. In the second study, the effect of feeding diets that differed in n-6 and n-3 FA ratios to breeder hens was investigated with regard to changes in composition of immune tissue, alteration of delayed-type-hypersensitivity (DTH) response, and LT production by platelets. Chicks hatched to hens fed these diets were also studied with regard to fatty acid composition of immune tissues and LT production by platelets at various stages of growth (7, 14, 21 days). A total of 72 breeder hens were randomly divided into three groups (n=24) and fed diets supplemented with either 3.0% (by weight) sunflower oil (SF0; rich in n-6 FA; Diet I), a mixture of 1.5% SF0 and 1.5% fish oil (Diet II), or 3.0% fish oil (FO; rich in n-3 FA; Diet III). Production of LTB₄ and LTB₅ by platelets stimulated with calcium ionophore A23187 were assessed by RP-HPLC. The hens fed Diet I synthesized 43.9 ± 2.5 ng of LTB₄ per 5x10⁶ cells compared to 13.3 ± 0.9 ng of LTB₄ from hens fed Diet II (p≤0.05). However, no LTB₄ was produced by hens fed Diet III. Production of LTB₅ by platelets of hens fed Diet III was 36.7 ± 4.9 ng compared to 47.4 ± 5.7 ng of LTB₅ from hens fed Diet II. No LTB₅ was produced by hens fed Diet I. The DTH reaction was smaller at 48 hrs post injection of bovine serum albumin in hens fed the 3% FO Diet III (p≤0.05). Fatty acid composition spleen and platelets in hens reflected the fatty acid composition of diets consumed by them (p≤0.05). Hatched chicks from hens fed Diet I produced significantly less LTB₄ at 14 days (p≤0.05) compared to 7- and 21-day-old chicks, which were not different from each other. Chicks from hens fed Diet II produced more LTB₄ at 21 days (p≤0.05) compared chicks from hens fed Diet III produced more LTB₄ at 7 and 21 days (p≤0.05) compared to 14-day-old chicks. There were no significant differences in LTB₅ production from chicks hatched to hens fed Diet III at 7 and 14 days of growth. By 21 days of growth, chicks hatched to hens fed Diet III showed decreased production of LTB₅ compared to 7- and 14-day-old chicks. The spleen and bursa tissue fatty acid composition in chicks at 7 and 14 days of age were similar to the maternal diet fatty acid composition, however, there were no significant differences in platelet fatty acid composition between the groups at different stages of growth. These results indicate that the type of fat in diets fed to breeder hens may alter the inflammatory response in hatched chicks, which could lead to less mortality and increased production performance in poultry.
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4948. [Article] Distribution and life history of the spiny dogfish (Squalus acanthias) off the Oregon and Washington coasts
This study examines the spatial and temporal distribution and life history of the "offshore" component of the Northeastern Pacific spiny dogfish (Squalus acanthias) population. Distribution was examined ...Citation Citation
- Title:
- Distribution and life history of the spiny dogfish (Squalus acanthias) off the Oregon and Washington coasts
- Author:
- Richards, Jaclyn M.
This study examines the spatial and temporal distribution and life history of the "offshore" component of the Northeastern Pacific spiny dogfish (Squalus acanthias) population. Distribution was examined in relation to latitude, depth, the Columbia River plume and large-scale climate changes. Fishery and survey data indicate that the Northeastern Pacific spiny dogfish population has a broad range along the Washington and Oregon coasts, with the highest abundance occurring off the northern Washington and central Oregon coasts. Catches, however, were patchy throughout the 37-year period of available survey data. In terms of depth, the greatest abundances of spiny dogfish were captured in shallow waters (55-184 m). An examination of the influence of the Columbia River plume using a generalized additive model (GAM) indicated that the fish were influenced significantly by the salinity, chlorophyll and surface temperature patterns associated with the plume, preferring the oceanic zone to the plume zone. In contrast, there was no indication that the catch-per-unit-effort of spiny dogfish was influenced by the Pacific Decadal Oscillation (PDO) or the El-Niño (ENSO) over 24-year period of the National Marine Fisheries (NMFS) triennial shelf groundfish survey (1977-2001). The multi-cohort age structure of the population, due to the spiny dogfish's late age at maturity and long lifespan, as well as the low fecundity make it difficult to detect the loss of a single cohort or two when examining abundance trends. Moreover, effects on abundance may be time-lagged, especially if, as is likely, the youngest cohort(s) is the most vulnerable life stage. Their absence would not become evident until they were large enough to have been captured by the survey gear. Sensitive abundance data and/or age-structured data would be needed to identify a pattern. I quantified the age, maturation and fecundity of the spiny dogfish and use these data to develop an age-structured matrix model to examine the sensitivity of the population's growth rate to changes in mortality (i.e. fishing). Female spiny dogfish in this population have an average age at 50% maturity of 28 years and males 20 years. Average length at 50% maturity was 85.0 cm for females and 71.5 cm for males. Female fecundity was extremely low, averaging eight pups per clutch biennially and ranging from four to 14. The number of pups increased with length, but not age. Using these data, a deterministic, female-based model was developed. Asymptotic population growth rate (λ) was determined to be very low, 1.01, and comparable to population growth rates calculated for "coastal" populations. When fishing mortality was incorporated into the model, the fishery was only sustainable when exploitation was low and strict size limits enforced. When fecundity was doubled, the population growth rate increased from 1% to 3% per year. This 33% increase in population growth was equivalent to the effect of a decrease in the age at first maturity of three years. Given that responses to changes in population demographics through shifts in fecundity or spawning frequency are likely constrained, responses would then seem likely to involve changes in age at maturity. These life history traits translate into a low potential population growth and as a consequence high susceptibility to overfishing. My findings indicate that the Northeastern Pacific spiny dogfish are relatively slow growing, late to mature, and have low fecundity and a patchy distribution, with large catches occurring off the northern Washington and central Oregon coasts in shallow waters (55-184 m). These life history traits and distributional patterns are useful in the development of population models to predict responses to environmental fluctuations or increased mortality and thus the management of the population. It is evident from my findings that periodic monitoring is necessary to track possible catch declines off the northern Washington and central Oregon coasts and prevent collapse of the population should it be targeted by a fishery and overfishing occur.
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4949. [Article] Flavor chemistry of blue cheese
Numerous attempts have been made to identify the flavor compounds in Blue cheese, however, duplication of Blue cheese flavor has not yet been accomplished. Therefore, it was desirable to make a qualitative ...Citation Citation
- Title:
- Flavor chemistry of blue cheese
- Author:
- Anderson, Dale Fredrick
Numerous attempts have been made to identify the flavor compounds in Blue cheese, however, duplication of Blue cheese flavor has not yet been accomplished. Therefore, it was desirable to make a qualitative and quantitative investigation of Blue cheese flavor compounds and to study the effect of certain microorganisms on Blue cheese flavor. The aroma fraction of Blue cheese was isolated by centrifugation of the cheese and molecular distillation of the recovered fat. The volatiles were separated by gas chromatography on packed columns containing polar and nonpolar phases and by temperature programmed capillary column gas chromatography. Relative retention time data and fast scan mass spectral analysis of the capillary column effluent were used to identify compounds in the aroma fraction. Compounds positively identified were as follows: 2-pentanone, 2-hexanone, 2-heptanone, 2-octanone, 2-nonanone, 2-decanone, 2-undecanone, 2-tridecanone, 2-propanol, 2-pentanol, 2-heptanol, 2-octanol, 2-nonanol, methyl butanoate, methyl hexanote, methyl octanoate, methyl decanoate, methyl dodecanoate, ethyl formate, ethyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, ethanal, 3-methyl butanal, 2-methyl butanol, 3-methyl butanol, 1-pentanol, benzene, and toluene. Tentatively identified compounds included acetone, delta-octalactone, delta-decalactone, methyl acetate, isopropyl hexanoate, 3-methylbutyl butanoate, pentyl hexanoate, ethyl-2-methylnonanoate, isopropyl decanoate, furfural, 2-methyl propanal, methanol, ethanol, 2-phenylethanol, cresyl methyl ether, dimethylcyclohexane, diacetyl, methyl mercaptan, and hydrogen sulfide. A combination of liquid-liquid column chromatography and gas-liquid chromatography was utilized to quantitate the major free fatty acids in Blue and Roquefort cheese samples. The average concentration (mg acid/kg cheese) in three Blue cheese samples was as follows: 2:0, 826; 4:0, 1, 448; 6:0, 909; 8:0, 771; 10:0, 1,318; 12:0, 1,588; 14:0, 5,856; 16:0, 12,789; 18:0, 4,243; 18:1, 12,455; 18:2, 1,072; 18:3, 987. Roquefort cheese was found to be proportionately more abundant in 8:0 and 10:0 acids and low in 4:0 acid compared to Blue cheese. No formic, propionic, or isovaleric acid was detected in any of the cheeses tested. A quantitative procedure involving adsorption chromatography, liquid-liquid chromatography and absorption spectrophotometry was used to isolate and measure the concentration of the C₃, C₅, C₇, C₉, and C₁₁ methyl ketones in the fat of Blue and Roquefort cheese. The average methyl ketone concentration (micromoles ketone/10 g cheese fat) of five Blue cheese samples was as follows: acetone, 1.7; 2-pentanone, 5.9; 2-heptanone, 11.2; 2-nonanone, 9.3; 2-undecanone, 2. 4. Considerable variation in ketone concentration was noted between samples, but no consistent differences were observed between Blue and Roquefort cheese. One Roquefort sample contained no acetone. The annount of ketone formed during cheese curing does not depend directly on the amount of available fatty acid precursor. There appears to be a selective conversion of the 8:0, and to a lesser extent the 6:0 and 10:0, fatty acids to methyl ketones by the Penicillium roqueforti spores. The concentration of the C₅, C₇, and C₉ secondary alcohols was determined in the same cheeses used for ketone analysis. The previously measured ketones acted as internal standards and facilitated a semi-quantitative calculation of alcohol concentrations from peak areas of gas chrorriatograms. The average alcohol concentration (micromoles alcohol/10 g cheese fat) in five Blue cheese samples was as follows: 2-pentanol, 0. 3; 2-heptanol, 2. 1; 2-nonanol, 0. 8. The alcohols were present in approximately the same ratios as their methyl ketone analogs, but at much lower concentrations. A synthetic Blue cheese flavor was prepared using a blend of butterfat, dry curd cottage cheese, cream, and salt as a base. The most typical flavor was obtained using the following' compounds: the 2:0, 4:0, 6:0, and 8:0 fatty acids at two-thirds the average concentration found in cheese; twice the average concentration of the C₃, C₅, C₇, C₉, and C₁₁ methyl ketones and C₅, C₇, and C₉ secondary alcohols found in cheese: 2.0 mg/kg of base of 2-phenylethanol; 1.5 mg/kg of base of ethyl butanoate; 6.0 mg/kg of base of both methyl hexanoate and methyl octanoate. Incorporation of higher acids caused a soapy flavor. The presence of 2-phenylethanol and the esters was judged as very important in duplicating Blue cheese flavor. The mycelia of Penicillium roqueforti appear to be more active in the reduction of methyl ketones to secondary alcohols than the spores. Yeasts associated with Blue cheese are capable of reducing methyl ketones to secondary alcohols. Yeasts also may play a role in Blue cheese flavor by producing ethanol and other alcohols and certain esters.
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4950. [Article] Science basis for changing forest structure to modify wildfire behavior and severity
Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical ...Citation Citation
- Title:
- Science basis for changing forest structure to modify wildfire behavior and severity
- Author:
- Graham, Russell T., McCaffrey, Sarah, Jain, Theresa B.
Fire, other disturbances, physical setting, weather, and climate shape the structure and function of forests throughout the Western United States. More than 80 years of fire research have shown that physical setting, fuels, and weather combine to determine wildfire intensity (the rate at which it consumes fuel) and severity (the effect fire has on vegetation, soils, buildings, watersheds, and so forth). Millions of acres of forestlands (mainly in dry forests dominated by ponderosa pine and/or Douglas-fir) contain a high accumulation of flammable fuels compared to conditions prior to the 20th century. Forests with high stem density and fuel loading combined with extreme fire weather conditions have led to severe and large wildfires (such as those seen in the summers of 2000, 2002, and 2003) that have put a number of important values at risk. Although homes in the path of a wildfire are perhaps the most immediately recognized value, these wildfires also put numerous other human and ecological values at risk, such as power grids, drinking water supplies, firefighter safety, critical habitat, soil productivity, and air quality. For a given set of weather conditions, fire behavior is strongly influenced by stand and fuel structure. Crown fires in the dry forest types represent an increasing challenge for fire management as well as a general threat to the ecology of these forests and the closely associated human values. Crown fires are dependent on the sequence of available fuels starting from the ground surface to the canopy. Limiting crown fire in these forests can be accomplished by actions that manage in concert the surface, ladder, and crown fuels. Reducing crown fire and wildland fire growth across landscapes decreases the chances of developing large wildfires that affect human values adjacent to forested areas. However, a narrow focus on minimizing crown fire potential will not necessarily reduce the damage to homes and ecosystems when fires do occur. Homes are often ignited by embers flying far from the fire front, and by surface fires. Fire effects on ecosystems can also occur during surface fires where surface and understory fuels and deep organic layers are sufficient to generate high temperatures for long periods. Fuel treatments can help produce forest structures and fuel characteristics that then reduce the likelihood that wildfires will cause large, rapid changes in biophysical conditions. Fuel treatments can also help modify fire behavior sufficiently so that some wildfires can be suppressed more easily. Subsequent, sustained fuel treatments can maintain these conditions. Different fuel reduction methods target different components of the fuel bed. Thinning mainly affects standing vegetation, and other types of fuel treatments such as prescribed fire and pile burning woody fuels are needed to modify the combustion environment of surface fuels. In forests that have not experienced fire for many decades, multiple fuel treatments—that is, thinning and surface fuel reduction—may be required to significantly affect crown fire and surface fire hazard. Fuel treatments cannot guarantee benign fire behavior but can reduce the probability that extreme fire behavior will occur. Fuel treatments can be designed to restore forest conditions to a more resilient and resistant condition than now exists in many forests, and subsequent management could maintain these conditions, particularly in dry forests (ponderosa pine and Douglas-fir) where crown fires were historically infrequent. The degree of risk reduction will depend to some degree on the level of investment, social and economic acceptability of treatments, and concurrent consideration of other resource values (for example, wildlife). This report describes the kinds, quality, amount, and gaps of scientific knowledge for making informed decisions on fuel treatments used to modify wildfire behavior and effects in dry forests of the interior Western United States (especially forests dominated by ponderosa pine and Douglas-fir). A review of scientific principles and applications relevant to fuel treatment primarily for the dry forests is provided for the following topics: fuels, fire hazard, fire behavior, fire effects, forest structure, treatment effects and longevity, landscape fuel patterns, and scientific tools useful for management and planning.