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• 961. [Article] Climate Change Effects on Arbuscular Mycorrhizal Fungi and Prairie Plants Along a Mediterranean Climate Gradient

  Arbuscular mycorrhizal fungi (AMF) provide numerous services to their plant symbionts. Understanding the effects of climate change on AMF, and the resulting plant responses, is a crucial factor in predicting ...

  Citation × Citation Citation Abstract Copy Title: Climate Change Effects on Arbuscular Mycorrhizal Fungi and Prairie Plants Along a Mediterranean Climate Gradient Author: Wilson, Hannah Year: 2013 Arbuscular mycorrhizal fungi (AMF) provide numerous services to their plant symbionts. Understanding the effects of climate change on AMF, and the resulting plant responses, is a crucial factor in predicting ecosystem responses on a global scale. We used a manipulative climate change experiment embedded within a natural climate gradient in Oregon and Washington to examine how the effects of future climate change on AMF-plant symbioses are mediated by soil water availability, soil nutrient availability, and vegetation dynamics. Using structural equation modeling, we found that the direct effect of increasing temperatures was to decrease AMF colonization. Indirect effects of temperature, mediated through other variables, canceled each other out. However, future shifts in these relationships could either exacerbate or mitigate the negative direct effect of temperature. As ecosystems in Mediterranean climates experience more intense droughts and heavier rains, decreases in AMF colonization could have substantial consequences for plant communities and ecosystem function. Title: Climate Change Effects on Arbuscular Mycorrhizal Fungi and Prairie Plants Along a Mediterranean Climate Gradient Author: Wilson, Hannah Year: 2013 Arbuscular mycorrhizal fungi (AMF) provide numerous services to their plant symbionts. Understanding the effects of climate change on AMF, and the resulting plant responses, is a crucial factor in predicting ecosystem responses on a global scale. We used a manipulative climate change experiment embedded within a natural climate gradient in Oregon and Washington to examine how the effects of future climate change on AMF-plant symbioses are mediated by soil water availability, soil nutrient availability, and vegetation dynamics. Using structural equation modeling, we found that the direct effect of increasing temperatures was to decrease AMF colonization. Indirect effects of temperature, mediated through other variables, canceled each other out. However, future shifts in these relationships could either exacerbate or mitigate the negative direct effect of temperature. As ecosystems in Mediterranean climates experience more intense droughts and heavier rains, decreases in AMF colonization could have substantial consequences for plant communities and ecosystem function. Close

• 962. [Article] Aggregational behavior in the boreal toad Bufo boreas boreas Baird and Girard

  The object of this study was to investigate the possibilities of tracing aggregational behavior among Bufo boreas boreas larvae with reference to tadpole development, and to attempt to determine what aggregational ...

  Citation × Citation Citation Abstract Copy Title: Aggregational behavior in the boreal toad Bufo boreas boreas Baird and Girard Author: Dorsch, Anthony James The object of this study was to investigate the possibilities of tracing aggregational behavior among Bufo boreas boreas larvae with reference to tadpole development, and to attempt to determine what aggregational factors initiate and maintain this behavior. Additionally, an attempt was made to determine the significance of temperature as an individual environmental factor. Field records were taken from three Oregon lakes during the summers of 1965 and 1966. Behavioral patterns were traced through the larval, metamorphic and juvenile phases of development. Temperatures were recorded with a Schultheis centigrade thermometer. Preliminary experiments were conducted to determine the effects of a thermal gradient on tadpole behavior. Aggregational behavior is expressed by these tadpoles throughout all but the first few weeks of the larval phase, through metamorphosis, and into the first season of juvenile life. Aggregational patterns are peculiar to respective developmental stages. Schooling is significant, and the serpentine patterns are unique to these larvae. Temperature appears to be a relevant factor in initiating and maintaining aggregation. Several other factors which require clarification are discussed. Title: Aggregational behavior in the boreal toad Bufo boreas boreas Baird and Girard Author: Dorsch, Anthony James The object of this study was to investigate the possibilities of tracing aggregational behavior among Bufo boreas boreas larvae with reference to tadpole development, and to attempt to determine what aggregational factors initiate and maintain this behavior. Additionally, an attempt was made to determine the significance of temperature as an individual environmental factor. Field records were taken from three Oregon lakes during the summers of 1965 and 1966. Behavioral patterns were traced through the larval, metamorphic and juvenile phases of development. Temperatures were recorded with a Schultheis centigrade thermometer. Preliminary experiments were conducted to determine the effects of a thermal gradient on tadpole behavior. Aggregational behavior is expressed by these tadpoles throughout all but the first few weeks of the larval phase, through metamorphosis, and into the first season of juvenile life. Aggregational patterns are peculiar to respective developmental stages. Schooling is significant, and the serpentine patterns are unique to these larvae. Temperature appears to be a relevant factor in initiating and maintaining aggregation. Several other factors which require clarification are discussed. Close

• 963. [Article] Some properties and reactions of umbellulone from the leaf oil of Coos Bay myrtle, Umbellularia californica

  The umbellulone was isolated from the myrtle oil by the sulfite method, which was found to be the most inexpensive and convenient method of obtaining the pure ketone. The umbellulone was hydrogenated in ...

  Citation × Citation Citation Abstract Copy Title: Some properties and reactions of umbellulone from the leaf oil of Coos Bay myrtle, Umbellularia californica Author: Kiyohiro, Leo Yukio The umbellulone was isolated from the myrtle oil by the sulfite method, which was found to be the most inexpensive and convenient method of obtaining the pure ketone. The umbellulone was hydrogenated in the vapor phase over a nickel catalyst, passing it through an electric tube furnace, in an attempt to compare the course of the reduction with that obtained by previous investigators operating upon a liquid phase. The products of each hydrogenation at different temperatures from 250° to 375°C. were analyzed for ketone, alcohol, and phenol contents, and for iodine value to determine unsaturation. Their physical constants, including specific gravity, optical rotation, and refractive index were also determined. The results so obtained were compared with those of the original ketone used and the following conclusions were shown:- 1. At temperatures below 300°C. partially saturated hydrogenated compounds were obtained. 2. At higher temperatures rearrangement took place converting umbellulone into phenols, specifically thymol. 3. The relative increase in alcohol content with a decrease in ketone content is probably due to a conversion of a dihydroumbellulone, which is first produced, to dihydroumbellulol or the fully saturated tetrahydroumbellulol, or possibly in part to the formation of menthone and its conversion to menthol. Title: Some properties and reactions of umbellulone from the leaf oil of Coos Bay myrtle, Umbellularia californica Author: Kiyohiro, Leo Yukio The umbellulone was isolated from the myrtle oil by the sulfite method, which was found to be the most inexpensive and convenient method of obtaining the pure ketone. The umbellulone was hydrogenated in the vapor phase over a nickel catalyst, passing it through an electric tube furnace, in an attempt to compare the course of the reduction with that obtained by previous investigators operating upon a liquid phase. The products of each hydrogenation at different temperatures from 250° to 375°C. were analyzed for ketone, alcohol, and phenol contents, and for iodine value to determine unsaturation. Their physical constants, including specific gravity, optical rotation, and refractive index were also determined. The results so obtained were compared with those of the original ketone used and the following conclusions were shown:- 1. At temperatures below 300°C. partially saturated hydrogenated compounds were obtained. 2. At higher temperatures rearrangement took place converting umbellulone into phenols, specifically thymol. 3. The relative increase in alcohol content with a decrease in ketone content is probably due to a conversion of a dihydroumbellulone, which is first produced, to dihydroumbellulol or the fully saturated tetrahydroumbellulol, or possibly in part to the formation of menthone and its conversion to menthol. Close

• 964. [Article] Electron-phonon interactions and de Haas-van Alphen effect in dilute non-magnetic alloys

  First the theory of electron-phonon contributions to the de Haas-van Alphen effect in normal systems (pure metals in the nonsuperconducting state ) is reviewed.Then a new derivation of the de Haas-van ...

  Citation × Citation Citation Abstract Copy Title: Electron-phonon interactions and de Haas-van Alphen effect in dilute non-magnetic alloys Author: Bharatiya, Narsingh Ramniwas First the theory of electron-phonon contributions to the de Haas-van Alphen effect in normal systems (pure metals in the nonsuperconducting state ) is reviewed.Then a new derivation of the de Haas-van Alphen oscillations for an interacting system is given.The result is applied to electron-phonon scattering to show that contrary to what might be expected,the Dingle temperature does not include electron- phonon scattering effects and,under reasonable approximations, indeed one again recovers the quasi-partcle formula for the amplitude in the interacting system;however,with the electron-phonon enhanced mass replacing the bare electron (free or band) mass.Also a calculation of the electron-phonon scattering in dilute non-magnetic alloys is presented in which an uncorrelated ensemble average of phonon Green's functions for the disordered system is used. It is found that for the extended'high temperature limit' derived above the various contributions to the normal electron self-energy (relevant to the dHvA effect) still have a linear temperature dependence.However,the electron-phonon mass enhancement factor λ now depends on two more parameters besides the effective mass of the electrons in the host. Title: Electron-phonon interactions and de Haas-van Alphen effect in dilute non-magnetic alloys Author: Bharatiya, Narsingh Ramniwas First the theory of electron-phonon contributions to the de Haas-van Alphen effect in normal systems (pure metals in the nonsuperconducting state ) is reviewed.Then a new derivation of the de Haas-van Alphen oscillations for an interacting system is given.The result is applied to electron-phonon scattering to show that contrary to what might be expected,the Dingle temperature does not include electron- phonon scattering effects and,under reasonable approximations, indeed one again recovers the quasi-partcle formula for the amplitude in the interacting system;however,with the electron-phonon enhanced mass replacing the bare electron (free or band) mass.Also a calculation of the electron-phonon scattering in dilute non-magnetic alloys is presented in which an uncorrelated ensemble average of phonon Green's functions for the disordered system is used. It is found that for the extended'high temperature limit' derived above the various contributions to the normal electron self-energy (relevant to the dHvA effect) still have a linear temperature dependence.However,the electron-phonon mass enhancement factor λ now depends on two more parameters besides the effective mass of the electrons in the host. Close

• 965. [Article] The relationship of temperature to pupal development rates of the western cherry fruit fly, Rhagoletis indifferens Curran

  Adult emergence studies conducted with Rhagoletis indifferens Curran reveal that diapause development in this insect is completed most rapidly at approximately 3°C. These results coupled with those reported ...

  Citation × Citation Citation Abstract Copy Title: The relationship of temperature to pupal development rates of the western cherry fruit fly, Rhagoletis indifferens Curran Author: VanKirk, James Ross Adult emergence studies conducted with Rhagoletis indifferens Curran reveal that diapause development in this insect is completed most rapidly at approximately 3°C. These results coupled with those reported by Brown (1978) confirm that chilling at 3°C. for ca. 200 days is best when high percent emergence, good synchrony of emergence, and relatively rapid completion of diapause development is required. Studies comparing emergence of field collected insects with that of insects chilled in the laboratory show that in 1978 diapause development in the field was near completion by the end of February. Similar studies may be necessary to pinpoint the end of diapause in the field population in any given year. A standard method was used to determine the thermal developmental threshold for use in degree-day models for adult emergence. This method yielded a value of 10.2°C. A slightly modified version of this standard method yielded a threshold of 11.7°C. A third method was used which entailed weighting data on the basis of the proportional occurrence of experimental incubation temperatures in the field. This method yielded a threshold value of 8.3°C. Comparison of the three thresholds using field emergence and temperature data for a five year period indicated that a model based upon the 8.3°C base threshold performed with less variation from year to year than did models based upon the other two thresholds. Title: The relationship of temperature to pupal development rates of the western cherry fruit fly, Rhagoletis indifferens Curran Author: VanKirk, James Ross Adult emergence studies conducted with Rhagoletis indifferens Curran reveal that diapause development in this insect is completed most rapidly at approximately 3°C. These results coupled with those reported by Brown (1978) confirm that chilling at 3°C. for ca. 200 days is best when high percent emergence, good synchrony of emergence, and relatively rapid completion of diapause development is required. Studies comparing emergence of field collected insects with that of insects chilled in the laboratory show that in 1978 diapause development in the field was near completion by the end of February. Similar studies may be necessary to pinpoint the end of diapause in the field population in any given year. A standard method was used to determine the thermal developmental threshold for use in degree-day models for adult emergence. This method yielded a value of 10.2°C. A slightly modified version of this standard method yielded a threshold of 11.7°C. A third method was used which entailed weighting data on the basis of the proportional occurrence of experimental incubation temperatures in the field. This method yielded a threshold value of 8.3°C. Comparison of the three thresholds using field emergence and temperature data for a five year period indicated that a model based upon the 8.3°C base threshold performed with less variation from year to year than did models based upon the other two thresholds. Close

• 966. [Article] Numerical study of natural convection in square partitioned and non-partitioned enclosures

  Heat transfer characteristics and associated temperature and flow fields for natural convection in two-dimensional, square, partitioned and non-partitioned enclosures have been determined for Grashof numbers ...

  Citation × Citation Citation Abstract Copy Title: Numerical study of natural convection in square partitioned and non-partitioned enclosures Author: Sukkaset, Prasart Heat transfer characteristics and associated temperature and flow fields for natural convection in two-dimensional, square, partitioned and non-partitioned enclosures have been determined for Grashof numbers ranging from 10³ to 10⁶. The vertical side walls of the enclosure are isothermal with all other surfaces assumed to be adiabatic. An adiabatic partition is oriented vertically with one edge on the enclosure floor. The dimensions and location of the partition were varied in order to investigate its effect of natural convection in the enclosure. Air was taken as the working fluid. Transport equations for vorticity and energy were solved using the QUICKEST scheme while the Poisson equation, for the steamfunction, was solved using the SOR method. For any Grashof number, temperature and flow fields in the region above the partition are not significantly different from those of the non-partitioned enclosure in the case of an aperture ratio of 0.75 or greater. An increase in the partition height or width results in modifying the temperature and flow fields and decreasing the average heat transfer across the enclosure. Title: Numerical study of natural convection in square partitioned and non-partitioned enclosures Author: Sukkaset, Prasart Heat transfer characteristics and associated temperature and flow fields for natural convection in two-dimensional, square, partitioned and non-partitioned enclosures have been determined for Grashof numbers ranging from 10³ to 10⁶. The vertical side walls of the enclosure are isothermal with all other surfaces assumed to be adiabatic. An adiabatic partition is oriented vertically with one edge on the enclosure floor. The dimensions and location of the partition were varied in order to investigate its effect of natural convection in the enclosure. Air was taken as the working fluid. Transport equations for vorticity and energy were solved using the QUICKEST scheme while the Poisson equation, for the steamfunction, was solved using the SOR method. For any Grashof number, temperature and flow fields in the region above the partition are not significantly different from those of the non-partitioned enclosure in the case of an aperture ratio of 0.75 or greater. An increase in the partition height or width results in modifying the temperature and flow fields and decreasing the average heat transfer across the enclosure. Close

• 967. [Article] Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes

  Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that ...

  Citation × Citation Citation Abstract Copy Title: Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes Author: Frey, Sarah Jean Kiuama Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then obtaining data at these scales present two major challenges to developing predictive models. In heterogeneous forested mountain landscapes I examined: A) the relative drivers of climatic variability at fine spatial scales under the forest canopy ('microclimate'), B) the influence of microclimate on local-scale occupancy dynamics of bird communities, and C) the effects of spatial scale and imperfect bird detection on long-term avian population trends. Climate change has been predicted to cause widespread biodiversity declines. However, the capacity of climate envelope models for predicting the future of biodiversity has been questioned due to the mismatch between the scale of available data (i.e., global climate models) and the scales at which organisms experience their environment. Local-scale variation in microclimate is hypothesized to provide potential ‘microrefugia’ for biodiversity, but the relative role of elevation, microtopography, and vegetation structure in driving microclimate is not well known. If the microrefugia hypothesis is true, I expected to see areas on the landscape that remained relatively cooler (i.e., buffered sites). To test this, I collected temperature data at 183 sites across elevation and forest structure gradients in complex terrain of the H. J. Andrews Experimental Forest in the Cascade Mountains of Oregon, USA (Chapter 2). I used boosted regression trees, a novel machine learning approach, to determine the relative influence of vegetation structure, microtopography, and elevation as drivers of microclimate and mapped fine-scale distributions of temperature across the landscape. Models performed extremely well on independent data - cross-validation correlations between testing and training data were 0.69 - 0.98 for ten selected climate variables. Elevation was the dominant driver in fine-scale microclimate patterns, although vegetation and microtopography also showed substantial relative influences. For instance, during the spring-summer transition, maximum monthly temperatures observed in old-growth sites were 2.6°C (95% CI: 1.8 - 3.3°C) cooler than plantation sites and minimum temperatures during winter months were 0.6°C (95% CI: 0.4 - 0.8°C) warmer. This suggests that older forest stands mediate changes in temperature by buffering against warming during summer months and moderating cold temperatures during the winter. Climate is generally considered most influential on species distributions at large spatial scales; however much microclimate variability exists within regional patterns. I tested whether this high degree of microclimate variability has relevance for predicting species distributions and occupancy dynamics of the Andrews Forest bird community. I collected bird occurrence data in 2012 and 2013 at all 183 sites with fine-scale temperature measurements. I used dynamic occupancy models to test the effects of temperature on occupancy and apparent within-season bird movement while statistically accounting for vegetation effects and imperfect bird detection (Chapter 3). Most species (87%) exhibited within-season shifts in response to local-scale temperature metrics. Effects of temperature on within-season occupancy dynamics were as large or larger (1 to 1.7 times) than vegetation. However, individual species were almost as likely to shift toward warmer sites as toward cooler sites, suggesting that microclimate preferences are species-specific. My results emphasize that high-resolution temperature data provide valuable insight into avian distribution dynamics in montane forest environments and that microclimate is an important variable in breeding season habitat selection by forest birds. I hypothesize that microclimate-associated distribution shifts may reflect species' potential for behavioral buffering from climate change in complex terrain. Factors influencing population trends often differ depending on the spatial scale under consideration. Further, accurate estimation of trends requires accounting for biases caused by imperfect detection. To test the degree to which population trends are consistent across scales, I estimated landscape-scale bird population trends from 1999-2012 for 38 species at the Hubbard Brook Experimental Forest (HBEF) in the White Mountains of New Hampshire, USA and compared them to regional and local trends (Chapter 4). I used a new method - open-population binomial mixture models - to test the hypothesis that imperfect detection in bird sampling has the potential to bias trend estimates. I also tested for generalities in species responses by predicting population trends as a function of life history and ecological traits. Landscape-scale trends were correlated with regional and local trends, but generally these correlations were weak (r = 0.12 - 0.4). Further, more species were declining at the regional scale compared to within the relatively undisturbed HBEF. Life history and ecological traits did not explain any of the variability in the HBEF trends. However, at the regional scale, species that occurred at higher elevations were more likely to be declining and species associated with older forests have increased. I hypothesize that these differences could be attributed to both elevated rates of land-use change in the broader region and the fact that the structure of regional data did not permit modeling of imperfect detection. Indeed, accounting for imperfect detection resulted in more accurate population trend estimates at the landscape scale; without accounting for detection we would have both missed trends and falsely identified trends where none existed. These results highlight two important cautions for trend analysis: 1) population trends estimated at fine spatial scales may not be extrapolated to broader scales and 2) accurate trends require accounting for imperfect detection. Title: Effects of spatial scale and heterogeneity on avian occupancy dynamics and population trends in forested mountain landscapes Author: Frey, Sarah Jean Kiuama Population trends and patterns in species distributions are the major currencies used to examine responses by biodiversity to changing environments. Effective conservation recommendations require that models of both distribution dynamics and population trends accurately reflect reality. However, identification of the appropriate temporal and spatial scales of animal response, and then obtaining data at these scales present two major challenges to developing predictive models. In heterogeneous forested mountain landscapes I examined: A) the relative drivers of climatic variability at fine spatial scales under the forest canopy ('microclimate'), B) the influence of microclimate on local-scale occupancy dynamics of bird communities, and C) the effects of spatial scale and imperfect bird detection on long-term avian population trends. Climate change has been predicted to cause widespread biodiversity declines. However, the capacity of climate envelope models for predicting the future of biodiversity has been questioned due to the mismatch between the scale of available data (i.e., global climate models) and the scales at which organisms experience their environment. Local-scale variation in microclimate is hypothesized to provide potential ‘microrefugia’ for biodiversity, but the relative role of elevation, microtopography, and vegetation structure in driving microclimate is not well known. If the microrefugia hypothesis is true, I expected to see areas on the landscape that remained relatively cooler (i.e., buffered sites). To test this, I collected temperature data at 183 sites across elevation and forest structure gradients in complex terrain of the H. J. Andrews Experimental Forest in the Cascade Mountains of Oregon, USA (Chapter 2). I used boosted regression trees, a novel machine learning approach, to determine the relative influence of vegetation structure, microtopography, and elevation as drivers of microclimate and mapped fine-scale distributions of temperature across the landscape. Models performed extremely well on independent data - cross-validation correlations between testing and training data were 0.69 - 0.98 for ten selected climate variables. Elevation was the dominant driver in fine-scale microclimate patterns, although vegetation and microtopography also showed substantial relative influences. For instance, during the spring-summer transition, maximum monthly temperatures observed in old-growth sites were 2.6°C (95% CI: 1.8 - 3.3°C) cooler than plantation sites and minimum temperatures during winter months were 0.6°C (95% CI: 0.4 - 0.8°C) warmer. This suggests that older forest stands mediate changes in temperature by buffering against warming during summer months and moderating cold temperatures during the winter. Climate is generally considered most influential on species distributions at large spatial scales; however much microclimate variability exists within regional patterns. I tested whether this high degree of microclimate variability has relevance for predicting species distributions and occupancy dynamics of the Andrews Forest bird community. I collected bird occurrence data in 2012 and 2013 at all 183 sites with fine-scale temperature measurements. I used dynamic occupancy models to test the effects of temperature on occupancy and apparent within-season bird movement while statistically accounting for vegetation effects and imperfect bird detection (Chapter 3). Most species (87%) exhibited within-season shifts in response to local-scale temperature metrics. Effects of temperature on within-season occupancy dynamics were as large or larger (1 to 1.7 times) than vegetation. However, individual species were almost as likely to shift toward warmer sites as toward cooler sites, suggesting that microclimate preferences are species-specific. My results emphasize that high-resolution temperature data provide valuable insight into avian distribution dynamics in montane forest environments and that microclimate is an important variable in breeding season habitat selection by forest birds. I hypothesize that microclimate-associated distribution shifts may reflect species' potential for behavioral buffering from climate change in complex terrain. Factors influencing population trends often differ depending on the spatial scale under consideration. Further, accurate estimation of trends requires accounting for biases caused by imperfect detection. To test the degree to which population trends are consistent across scales, I estimated landscape-scale bird population trends from 1999-2012 for 38 species at the Hubbard Brook Experimental Forest (HBEF) in the White Mountains of New Hampshire, USA and compared them to regional and local trends (Chapter 4). I used a new method - open-population binomial mixture models - to test the hypothesis that imperfect detection in bird sampling has the potential to bias trend estimates. I also tested for generalities in species responses by predicting population trends as a function of life history and ecological traits. Landscape-scale trends were correlated with regional and local trends, but generally these correlations were weak (r = 0.12 - 0.4). Further, more species were declining at the regional scale compared to within the relatively undisturbed HBEF. Life history and ecological traits did not explain any of the variability in the HBEF trends. However, at the regional scale, species that occurred at higher elevations were more likely to be declining and species associated with older forests have increased. I hypothesize that these differences could be attributed to both elevated rates of land-use change in the broader region and the fact that the structure of regional data did not permit modeling of imperfect detection. Indeed, accounting for imperfect detection resulted in more accurate population trend estimates at the landscape scale; without accounting for detection we would have both missed trends and falsely identified trends where none existed. These results highlight two important cautions for trend analysis: 1) population trends estimated at fine spatial scales may not be extrapolated to broader scales and 2) accurate trends require accounting for imperfect detection. Close

• 968. [Article] Optimization of feeding schedules for coho salmon in the hatchery environment

  A growth model is developed for coho salmon which accounts for temperatures and feeding rates typically encountered in fish hatchery operation. Feeding rates utilized by the model ranged from maintenance ...

  Citation × Citation Citation Abstract Copy Title: Optimization of feeding schedules for coho salmon in the hatchery environment Author: Corey, Philip David A growth model is developed for coho salmon which accounts for temperatures and feeding rates typically encountered in fish hatchery operation. Feeding rates utilized by the model ranged from maintenance to maximum utilizable rations. The model is derived from an empirical equation for maximum growth rate, and a theoretical equation for net energy utilization. The resultant equation is modified to improve fit at higher feeding levels. Calibration is accomplished with experimentally obtained data. The model is similar to one developed by G.D. Stauffer, but represents an improvement because points on the growth curve between maintenance and maximum ration can be fitted even if maintenance and maximum requirements are obtained independently. An optimization method is then developed using this growth model that determines, for a given temperature regime, a feeding schedule that minimizes total food consumption for a given rearing period. The method is then extended to determine simultaneously feeding schedules and temperature regimes that minimize total food consumption. Title: Optimization of feeding schedules for coho salmon in the hatchery environment Author: Corey, Philip David A growth model is developed for coho salmon which accounts for temperatures and feeding rates typically encountered in fish hatchery operation. Feeding rates utilized by the model ranged from maintenance to maximum utilizable rations. The model is derived from an empirical equation for maximum growth rate, and a theoretical equation for net energy utilization. The resultant equation is modified to improve fit at higher feeding levels. Calibration is accomplished with experimentally obtained data. The model is similar to one developed by G.D. Stauffer, but represents an improvement because points on the growth curve between maintenance and maximum ration can be fitted even if maintenance and maximum requirements are obtained independently. An optimization method is then developed using this growth model that determines, for a given temperature regime, a feeding schedule that minimizes total food consumption for a given rearing period. The method is then extended to determine simultaneously feeding schedules and temperature regimes that minimize total food consumption. Close

• 969. [Article] Studies on the germination and growth of Anisogramma anomala Peck (Muller) in vitro

  This study examined the effects of pH, temperature, washing, and post-hydration drying on germination of Anisogramma anomala ascopores. Spores germinate most readily in the temperature range of 5 to 15 ...

  Citation × Citation Citation Abstract Copy Title: Studies on the germination and growth of Anisogramma anomala Peck (Muller) in vitro Author: Lightfoot, Richard (Richard Thomas), 1958- This study examined the effects of pH, temperature, washing, and post-hydration drying on germination of Anisogramma anomala ascopores. Spores germinate most readily in the temperature range of 5 to 15 degrees C, with an optimal temperature of 10 degrees (1 sd=0.05). Growth was best in the pH range of 5 to 6. Washed ascopores germinate at significantly higher rates than unwashed spores (P=.05, .01, and .06 for three experiments). Germination rate declined sharply with increasing post-hydration drying, with 5 minutes of drying resulting in a 45% reduction in germination. After one hour of drying, spore germination was reduced by 98.5%. Those environmental factors which were optimal for germination in vitro reflected prevailing field conditions during the natural host infection period. The growth of A. anomala on artificial meduium is described. The germination process includes the following series of events: (1) spore hydration and swelling, (2) emergence of the germ tube, (3) vesicle formation, (4) production of hyphal initials, and (5) hyphal growth. Attempts to maintain cultures of A. anomala for longer than several months were unsuccessful. Title: Studies on the germination and growth of Anisogramma anomala Peck (Muller) in vitro Author: Lightfoot, Richard (Richard Thomas), 1958- This study examined the effects of pH, temperature, washing, and post-hydration drying on germination of Anisogramma anomala ascopores. Spores germinate most readily in the temperature range of 5 to 15 degrees C, with an optimal temperature of 10 degrees (1 sd=0.05). Growth was best in the pH range of 5 to 6. Washed ascopores germinate at significantly higher rates than unwashed spores (P=.05, .01, and .06 for three experiments). Germination rate declined sharply with increasing post-hydration drying, with 5 minutes of drying resulting in a 45% reduction in germination. After one hour of drying, spore germination was reduced by 98.5%. Those environmental factors which were optimal for germination in vitro reflected prevailing field conditions during the natural host infection period. The growth of A. anomala on artificial meduium is described. The germination process includes the following series of events: (1) spore hydration and swelling, (2) emergence of the germ tube, (3) vesicle formation, (4) production of hyphal initials, and (5) hyphal growth. Attempts to maintain cultures of A. anomala for longer than several months were unsuccessful. Close

• 970. [Article] Estimation of transmission dynamics of the Ceratomyxa shasta actinospore to the salmonid host

  This is the publisher’s final pdf. The published article is copyrighted by Cambridge University Press and can be found at: http://www.cambridge.org/.

  Citation × Citation Citation Abstract Copy Title: Estimation of transmission dynamics of the Ceratomyxa shasta actinospore to the salmonid host Author: Bartholomew, J. L., Ray, R. A. This is the publisher’s final pdf. The published article is copyrighted by Cambridge University Press and can be found at: http://www.cambridge.org/. Title: Estimation of transmission dynamics of the Ceratomyxa shasta actinospore to the salmonid host Author: Bartholomew, J. L., Ray, R. A. This is the publisher’s final pdf. The published article is copyrighted by Cambridge University Press and can be found at: http://www.cambridge.org/. Close