Search

Search Results

• 2211. [Article] Patterns in responses of an amphibian assemblage to wetland restoration

  Wetland restoration success in attaining wildlife conservation goals can be confounded by the presence of multiple biological invaders. Wetland management activities typically target invasive plants, ...

  Citation × Citation Citation Abstract Copy Title: Patterns in responses of an amphibian assemblage to wetland restoration Author: Rowe, Jennifer C. Wetland restoration success in attaining wildlife conservation goals can be confounded by the presence of multiple biological invaders. Wetland management activities typically target invasive plants, but bottom-up responses of higher trophic levels in novel communities are difficult to predict. We surveyed plant and amphibian assemblages at 26 sites enrolled in the Wetlands Reserve Program (WRP) in the Willamette Valley, Oregon to determine the relative importance of plant management, non-native species presence, and surrounding landscape for amphibians across multiple life history stages. Explanatory variables negatively associated with native anuran counts included percent invasive plant cover, invasive bullfrog counts, non-native fish presence, and area of urban land cover. In addition, native anurans were positively associated with WRP site age, suggesting that the benefits of restored wetlands may increase over time. Although invasive plant management provided indirect benefits to native amphibians, the most effective way to enhance native amphibian populations may be through eliminating the strong top-down forces exerted by non-native vertebrates. We also explored the impact of restoration activities on predator/prey dynamics by analyzing bullfrog diet contents. We sampled vegetation and analyzed bullfrog diet contents from 10 WRP wetlands categorized by management intensity and hydrology to determine whether prey consumption patterns (abundance, richness, and % large prey), diet breadth, and dietary community (based on taxonomic and prey size composition) differed among wetlands categorized by management regime and hydroperiod. We found disparities in the diet breadth with respect to wetland categories, with bullfrogs consuming a disproportionate abundance of few prey orders at actively managed sites. Diet breadth could have been influenced by frequent applications of restoration treatments, as invertebrate species richness and abundance is often negatively linked to habitat disturbance. Dietary taxonomic composition also differed between wetland groups, but prey size composition did not. Instead, prey size was strongly influenced by site-level vegetation covariates; large-bodied prey consumption was positively associated with plant species richness. However, diet dry mass was highest in wetlands with high invasive plant cover, suggesting that other factors, such as foraging activity rates, should be considered to fully understand how bullfrogs meet energy demands in managed wetlands. Variation in native and invasive amphibian responses to wetland restoration efforts may provide important information on how habitat structure and composition influence trophic dynamics. Given that the outcomes of plant control on wildlife may not follow planned trajectories in invasive-dominated systems, this research addresses the need for a community approach to assessments of restoration success. Title: Patterns in responses of an amphibian assemblage to wetland restoration Author: Rowe, Jennifer C. Wetland restoration success in attaining wildlife conservation goals can be confounded by the presence of multiple biological invaders. Wetland management activities typically target invasive plants, but bottom-up responses of higher trophic levels in novel communities are difficult to predict. We surveyed plant and amphibian assemblages at 26 sites enrolled in the Wetlands Reserve Program (WRP) in the Willamette Valley, Oregon to determine the relative importance of plant management, non-native species presence, and surrounding landscape for amphibians across multiple life history stages. Explanatory variables negatively associated with native anuran counts included percent invasive plant cover, invasive bullfrog counts, non-native fish presence, and area of urban land cover. In addition, native anurans were positively associated with WRP site age, suggesting that the benefits of restored wetlands may increase over time. Although invasive plant management provided indirect benefits to native amphibians, the most effective way to enhance native amphibian populations may be through eliminating the strong top-down forces exerted by non-native vertebrates. We also explored the impact of restoration activities on predator/prey dynamics by analyzing bullfrog diet contents. We sampled vegetation and analyzed bullfrog diet contents from 10 WRP wetlands categorized by management intensity and hydrology to determine whether prey consumption patterns (abundance, richness, and % large prey), diet breadth, and dietary community (based on taxonomic and prey size composition) differed among wetlands categorized by management regime and hydroperiod. We found disparities in the diet breadth with respect to wetland categories, with bullfrogs consuming a disproportionate abundance of few prey orders at actively managed sites. Diet breadth could have been influenced by frequent applications of restoration treatments, as invertebrate species richness and abundance is often negatively linked to habitat disturbance. Dietary taxonomic composition also differed between wetland groups, but prey size composition did not. Instead, prey size was strongly influenced by site-level vegetation covariates; large-bodied prey consumption was positively associated with plant species richness. However, diet dry mass was highest in wetlands with high invasive plant cover, suggesting that other factors, such as foraging activity rates, should be considered to fully understand how bullfrogs meet energy demands in managed wetlands. Variation in native and invasive amphibian responses to wetland restoration efforts may provide important information on how habitat structure and composition influence trophic dynamics. Given that the outcomes of plant control on wildlife may not follow planned trajectories in invasive-dominated systems, this research addresses the need for a community approach to assessments of restoration success. Close

• 2212. [Article] A micro data flow (MDF) : a data flow approach to self-timed VLSI system design for DSP

  Synchronization is one of the important issues in digital system design. While other approaches have been intriguing, up until now a globally clocked timing discipline has been the dominant design philosophy. ...

  Citation × Citation Citation Abstract Copy Title: A micro data flow (MDF) : a data flow approach to self-timed VLSI system design for DSP Author: Merani, Lalit T. Synchronization is one of the important issues in digital system design. While other approaches have been intriguing, up until now a globally clocked timing discipline has been the dominant design philosophy. However, we have reached the point, with advances in technology, where other options should be given serious consideration. VLSI promises great processing power at low cost. This increase in computation power has been obtained by scaling the digital IC process. But as this scaling continues, it is doubtful that the advantages of faster devices can be fully exploited. This is because the clock periods are getting much smaller in relation to the interconnect propagation delays, even within a single chip and certainly at the board and backplane level. In this thesis, some alternative approaches to synchronization in digital system design are described and developed. We owe these techniques to a long history of effort in both digital computational system design as well as digital communication system design. The latter field is relevant because large propagation delays have always been a dominant consideration in its design methods. Asynchronous design gives better performance than comparable synchronous design in situations for which a global synchronization with a high speed clock becomes a constraint for greater system throughput. Asynchronous circuits with unbounded gate delays, or self-timed digital circuit can be designed by employing either of two request-acknowledge protocols 4-cycle and 2-cycle. We will also present an alternative approach to the problem of mapping computation algorithms directly into asynchronous circuits. Data flow graph or language is used to describe the computation algorithms. The data flow primitives have been designed using both the 2-cycle and 4-cycle signaling schemes which are compared in terms of performance and transistor count. The 2-cycle implementations prove to be better than their 4-cycle counterparts. A promising application of self-timed design is in high performance DSP systems. Since there is no global constraint of clock distribution, localized forwardonly connection allows computation to be extended and sped up using pipelining. A decimation filter was designed and simulated to check the system level performance of the two protocols. Simulations were carried out using VHDL for high level definition of the design. The simulation results will demonstrate not only the efficacy of our synthesis procedure but also the improved efficiency of the 2-cycle scheme over the 4- cycle scheme. Title: A micro data flow (MDF) : a data flow approach to self-timed VLSI system design for DSP Author: Merani, Lalit T. Synchronization is one of the important issues in digital system design. While other approaches have been intriguing, up until now a globally clocked timing discipline has been the dominant design philosophy. However, we have reached the point, with advances in technology, where other options should be given serious consideration. VLSI promises great processing power at low cost. This increase in computation power has been obtained by scaling the digital IC process. But as this scaling continues, it is doubtful that the advantages of faster devices can be fully exploited. This is because the clock periods are getting much smaller in relation to the interconnect propagation delays, even within a single chip and certainly at the board and backplane level. In this thesis, some alternative approaches to synchronization in digital system design are described and developed. We owe these techniques to a long history of effort in both digital computational system design as well as digital communication system design. The latter field is relevant because large propagation delays have always been a dominant consideration in its design methods. Asynchronous design gives better performance than comparable synchronous design in situations for which a global synchronization with a high speed clock becomes a constraint for greater system throughput. Asynchronous circuits with unbounded gate delays, or self-timed digital circuit can be designed by employing either of two request-acknowledge protocols 4-cycle and 2-cycle. We will also present an alternative approach to the problem of mapping computation algorithms directly into asynchronous circuits. Data flow graph or language is used to describe the computation algorithms. The data flow primitives have been designed using both the 2-cycle and 4-cycle signaling schemes which are compared in terms of performance and transistor count. The 2-cycle implementations prove to be better than their 4-cycle counterparts. A promising application of self-timed design is in high performance DSP systems. Since there is no global constraint of clock distribution, localized forwardonly connection allows computation to be extended and sped up using pipelining. A decimation filter was designed and simulated to check the system level performance of the two protocols. Simulations were carried out using VHDL for high level definition of the design. The simulation results will demonstrate not only the efficacy of our synthesis procedure but also the improved efficiency of the 2-cycle scheme over the 4- cycle scheme. Close

• 2213. [Article] "Her Hypnotic Eyes" : Reading the Optical in Aaron Douglas’s Aspects of Negro Life and Nella Larsen's Passing

  This thesis examines two cultural productions of the Harlem Renaissance: Aaron Douglas's mural series, Aspects of Negro Life, and Nella Larsen's novel Passing. I read these works together because, more ...

  Citation × Citation Citation Abstract Copy Title: "Her Hypnotic Eyes" : Reading the Optical in Aaron Douglas’s Aspects of Negro Life and Nella Larsen's Passing Author: Barkley, Charles K. This thesis examines two cultural productions of the Harlem Renaissance: Aaron Douglas's mural series, Aspects of Negro Life, and Nella Larsen's novel Passing. I read these works together because, more than their shared time period, they showcase an attention to the visual. Both Larsen and Douglas's works are concerned with the power of the look, and, in turn, question who gets to look and how that look shapes new modes of thought for the viewer or reader. Chapter one examines Douglas's mural series, linking his artistic style to Orphism, an optics-centered art form popularized in Europe in the 1910s. I argue that Douglas's adaptation of this art form allows him to articulate a combined focus on the optical and historical together. This combination works to unsettle essentialist ideas about race and to question a predominant strain of optimistic thinking about the role of historical narratives for African American racial advancement, exemplified by the work of Arthur Schomburg. The chapter briefly surveys Orphism and optical theory of the 1910s as a separate phenomenon from Douglas's 1930s project. With this historical context in place, I read each of the four murals in the series to highlight the ways in which the viewer's eye is called to look across the canvas. By ruminating on the gaze as Douglas invites us to, the chapter shows that sight is always interwoven with history. Chapter two examines Nella Larsen's Passing, exploring the ways that sight can but does not always grant agency to the one who looks. I argue that Passing's obsession with sight functions as a key part of the novel's larger question about the relationship between agency and control. By presenting disparate narratives about the power of vision, the novel undercuts a singular understanding of agency. In making this argument, the chapter draws heavily from Frantz Fanon's Black Skin, White Masks and bell hooks' Black Looks. These two theorists chart a link between sight, agency, and control through a theory of the gaze. Engaging their ideas, the chapter examines the complicated iterations of the gaze throughout the text, with a primary focus on the looking relationship between the novel's protagonist, Irene Redfield, and her childhood friend, Clare Kendry. Read together, the chapters highlight the varying conceptions of the gaze during the Harlem Renaissance. Title: "Her Hypnotic Eyes" : Reading the Optical in Aaron Douglas’s Aspects of Negro Life and Nella Larsen's Passing Author: Barkley, Charles K. This thesis examines two cultural productions of the Harlem Renaissance: Aaron Douglas's mural series, Aspects of Negro Life, and Nella Larsen's novel Passing. I read these works together because, more than their shared time period, they showcase an attention to the visual. Both Larsen and Douglas's works are concerned with the power of the look, and, in turn, question who gets to look and how that look shapes new modes of thought for the viewer or reader. Chapter one examines Douglas's mural series, linking his artistic style to Orphism, an optics-centered art form popularized in Europe in the 1910s. I argue that Douglas's adaptation of this art form allows him to articulate a combined focus on the optical and historical together. This combination works to unsettle essentialist ideas about race and to question a predominant strain of optimistic thinking about the role of historical narratives for African American racial advancement, exemplified by the work of Arthur Schomburg. The chapter briefly surveys Orphism and optical theory of the 1910s as a separate phenomenon from Douglas's 1930s project. With this historical context in place, I read each of the four murals in the series to highlight the ways in which the viewer's eye is called to look across the canvas. By ruminating on the gaze as Douglas invites us to, the chapter shows that sight is always interwoven with history. Chapter two examines Nella Larsen's Passing, exploring the ways that sight can but does not always grant agency to the one who looks. I argue that Passing's obsession with sight functions as a key part of the novel's larger question about the relationship between agency and control. By presenting disparate narratives about the power of vision, the novel undercuts a singular understanding of agency. In making this argument, the chapter draws heavily from Frantz Fanon's Black Skin, White Masks and bell hooks' Black Looks. These two theorists chart a link between sight, agency, and control through a theory of the gaze. Engaging their ideas, the chapter examines the complicated iterations of the gaze throughout the text, with a primary focus on the looking relationship between the novel's protagonist, Irene Redfield, and her childhood friend, Clare Kendry. Read together, the chapters highlight the varying conceptions of the gaze during the Harlem Renaissance. Close

• 2214. [Article] Community leaders' perspectives of a rural community college's impact on community development

  The purpose of this qualitative research study was to examine the role a rural community college plays in the development of its community, using a holistic, community-based lens that considered college ...

  Citation × Citation Citation Abstract Copy Title: Community leaders' perspectives of a rural community college's impact on community development Author: Thomas, Reine M. The purpose of this qualitative research study was to examine the role a rural community college plays in the development of its community, using a holistic, community-based lens that considered college and community context, interactions and results to answer the question: How does the rural community college impact the development of the rural community? While the community college's connection to the local community is largely inherent, a full understanding of community college-community interaction and the impact of those interactions on the community as a whole is often difficult to articulate. Given the context of today's education accountability requirements, it is advantageous to develop a more comprehensive understanding of the community college with regard to community impact and public benefit -- for community college practitioners, the public, and state and local policy-makers. A social constructivist research perspective, a case study research strategy, and a single case design were employed in this study. The case for this study was a rural Northwest community and the community college within it. The community college was classified as a small, rural-serving college by the Carnegie Classification of Colleges and Universities. A logic model design guided the study. Study participants included: elected officials; business and industry executives; and health, education and human services leaders. A combination of document review, participant observation, and interviews was used to answer the research questions: (a) What is the context of this community and this community college? (b) In what ways do the college and the community interact and engage? (c) What are the results of the college-community engagement? Examination of the data revealed several major themes and five significant findings: 1. The community defines itself through a regional, rural lens and is characterized by an interconnectedness of its people to the land and to the history of the region. 2. The college and the community invest in reciprocal relationships and collaborate on mutually beneficial pursuits. 3. An improved regional economy and skilled-up workforce are identified as positive community changes – and the community college’s contributions to those positive changes are cited as a public benefit. 4. A community leadership network with increased confidence in collaboration, understanding of community assets, and efficacy in community development is recognized as a positive community change -- and the community college's contributions to those positive changes are cited as a public benefit. 5. An enhanced community image and an optimistic community outlook are identified as positive community changes -- and the community college’s contributions to those positive changes are cited as a public benefit. When these findings are taken into account with the related literature, this study offers considerations for practice and further research among community college, civic, and policy leaders.   Title: Community leaders' perspectives of a rural community college's impact on community development Author: Thomas, Reine M. The purpose of this qualitative research study was to examine the role a rural community college plays in the development of its community, using a holistic, community-based lens that considered college and community context, interactions and results to answer the question: How does the rural community college impact the development of the rural community? While the community college's connection to the local community is largely inherent, a full understanding of community college-community interaction and the impact of those interactions on the community as a whole is often difficult to articulate. Given the context of today's education accountability requirements, it is advantageous to develop a more comprehensive understanding of the community college with regard to community impact and public benefit -- for community college practitioners, the public, and state and local policy-makers. A social constructivist research perspective, a case study research strategy, and a single case design were employed in this study. The case for this study was a rural Northwest community and the community college within it. The community college was classified as a small, rural-serving college by the Carnegie Classification of Colleges and Universities. A logic model design guided the study. Study participants included: elected officials; business and industry executives; and health, education and human services leaders. A combination of document review, participant observation, and interviews was used to answer the research questions: (a) What is the context of this community and this community college? (b) In what ways do the college and the community interact and engage? (c) What are the results of the college-community engagement? Examination of the data revealed several major themes and five significant findings: 1. The community defines itself through a regional, rural lens and is characterized by an interconnectedness of its people to the land and to the history of the region. 2. The college and the community invest in reciprocal relationships and collaborate on mutually beneficial pursuits. 3. An improved regional economy and skilled-up workforce are identified as positive community changes – and the community college’s contributions to those positive changes are cited as a public benefit. 4. A community leadership network with increased confidence in collaboration, understanding of community assets, and efficacy in community development is recognized as a positive community change -- and the community college's contributions to those positive changes are cited as a public benefit. 5. An enhanced community image and an optimistic community outlook are identified as positive community changes -- and the community college’s contributions to those positive changes are cited as a public benefit. When these findings are taken into account with the related literature, this study offers considerations for practice and further research among community college, civic, and policy leaders.   Close

• 2215. [Article] Juvenile Rockfish (Sebastes spp.) Community Composition and Habitat use of Yaquina Bay, Oregon

  Estuaries, which provide viable habitat for a plethora of fish and invertebrate species, are being increasingly impacted by anthropogenic and natural forces. Estuaries are important nursery habitat for ...

  Citation × Citation Citation Abstract Copy Title: Juvenile Rockfish (Sebastes spp.) Community Composition and Habitat use of Yaquina Bay, Oregon Author: Lindsley, Amy J. Estuaries, which provide viable habitat for a plethora of fish and invertebrate species, are being increasingly impacted by anthropogenic and natural forces. Estuaries are important nursery habitat for young-of-the-year (YOY) Pacific rockfish (Sebastes spp.). Yaquina Bay, a marine-dominated estuary on the central Oregon Coast, served as a study site for the estuarine use of juvenile rockfishes, and large numbers of juvenile rockfish have been captured in this bay. Nursery habitats must provide rearing habitat, adequate food resources and refuge. A vital but lacking connection in our understanding of estuaries as nursery habitat is how rockfishes use the different microhabitats within an estuarine ecosystem. As habitats structure biotic communities, determining the ecological requirements for juvenile rockfish habitats that minimize mortality, maximize growth and increase population numbers will assist managers and biologists in managing and protecting critical high-quality nursery areas. This study provides insight into Oregon rockfish life history, evaluating the spatial and temporal use of estuarine nursery habitat by juvenile rockfishes. The primary objectives were to (1) determine which species of rockfish utilize Yaquina Bay, (2) determine seasonal variations in abundance, and (3) assess the utilization of natural (eelgrass beds, Zostera marina) versus anthropogenic (piers) estuarine habitat. I conducted a mark-recapture study of juvenile rockfishes to begin to elucidate how these species may be using different habitats in the bay. This study provides evidence for the presence of previously undocumented rockfish species, the overwinter persistence of juvenile rockfish in the estuary, some degree of site fidelity, and apparent minimal movement of juvenile rockfish in the Yaquina Bay estuary during the period of this study, as well as a shift in rockfish community dominance from S. melanops to S. maliger and S. caurinus. The survival and recapture of juveniles in both natural (Z. marina) and anthropogenic (piers) habitat demonstrates rockfishes’ successful use of multiple Yaquina Bay habitat types as nursery grounds year-round. There is seasonal variability in rockfish use of the anthropogenic and natural habitat, with the anthropogenic habitats having an overall higher capture rate and a higher occurrence of larger rockfish. All eight species S. melanops, S. maliger, S. caurinus, S. paucispinis, S. flavidus, S. nebulosus, S. pinniger and S. auriculatus are present in the natural, Z. marina habitat. Sebastes pinniger and S. auriculatus are absent from anthropogenic, pier habitat. The implications of determining habitat parameters, community interactions, seasonal changes of the fish community, and ecosystem mechanisms may be invaluable to support further recreational and commercial fishing and help sustain or increase adult populations. My findings present a significant contribution towards the proper management and conservation of essential habitat for rockfish, a group of species with high commercial value and substantial recreational harvest. Title: Juvenile Rockfish (Sebastes spp.) Community Composition and Habitat use of Yaquina Bay, Oregon Author: Lindsley, Amy J. Estuaries, which provide viable habitat for a plethora of fish and invertebrate species, are being increasingly impacted by anthropogenic and natural forces. Estuaries are important nursery habitat for young-of-the-year (YOY) Pacific rockfish (Sebastes spp.). Yaquina Bay, a marine-dominated estuary on the central Oregon Coast, served as a study site for the estuarine use of juvenile rockfishes, and large numbers of juvenile rockfish have been captured in this bay. Nursery habitats must provide rearing habitat, adequate food resources and refuge. A vital but lacking connection in our understanding of estuaries as nursery habitat is how rockfishes use the different microhabitats within an estuarine ecosystem. As habitats structure biotic communities, determining the ecological requirements for juvenile rockfish habitats that minimize mortality, maximize growth and increase population numbers will assist managers and biologists in managing and protecting critical high-quality nursery areas. This study provides insight into Oregon rockfish life history, evaluating the spatial and temporal use of estuarine nursery habitat by juvenile rockfishes. The primary objectives were to (1) determine which species of rockfish utilize Yaquina Bay, (2) determine seasonal variations in abundance, and (3) assess the utilization of natural (eelgrass beds, Zostera marina) versus anthropogenic (piers) estuarine habitat. I conducted a mark-recapture study of juvenile rockfishes to begin to elucidate how these species may be using different habitats in the bay. This study provides evidence for the presence of previously undocumented rockfish species, the overwinter persistence of juvenile rockfish in the estuary, some degree of site fidelity, and apparent minimal movement of juvenile rockfish in the Yaquina Bay estuary during the period of this study, as well as a shift in rockfish community dominance from S. melanops to S. maliger and S. caurinus. The survival and recapture of juveniles in both natural (Z. marina) and anthropogenic (piers) habitat demonstrates rockfishes’ successful use of multiple Yaquina Bay habitat types as nursery grounds year-round. There is seasonal variability in rockfish use of the anthropogenic and natural habitat, with the anthropogenic habitats having an overall higher capture rate and a higher occurrence of larger rockfish. All eight species S. melanops, S. maliger, S. caurinus, S. paucispinis, S. flavidus, S. nebulosus, S. pinniger and S. auriculatus are present in the natural, Z. marina habitat. Sebastes pinniger and S. auriculatus are absent from anthropogenic, pier habitat. The implications of determining habitat parameters, community interactions, seasonal changes of the fish community, and ecosystem mechanisms may be invaluable to support further recreational and commercial fishing and help sustain or increase adult populations. My findings present a significant contribution towards the proper management and conservation of essential habitat for rockfish, a group of species with high commercial value and substantial recreational harvest. Close

• 2216. [Article] Albacore tuna catches in the Northeast Pacific during summer 1969 as related to selected ocean conditions

  Oregon's commercial fishery for albacore tuna (Thunnus alalunga) is large, valuable, and variable. Little is known, however, about the oceanographic factors which determine abundance and distribution of albacore. Primarily ...

  Citation × Citation Citation Abstract Copy Title: Albacore tuna catches in the Northeast Pacific during summer 1969 as related to selected ocean conditions Author: Panshin, Daniel Alexis Oregon's commercial fishery for albacore tuna (Thunnus alalunga) is large, valuable, and variable. Little is known, however, about the oceanographic factors which determine abundance and distribution of albacore. Primarily using logbook data contributed by fishermen, this study compares albacore catches with selected ocean conditions. The study is limited to troll-caught fish taken during the summer of 1969 off the Pacific Northwest. The location and success of commercial albacore catches were analyzed with respect to the sea-surface temperature field. Also examined was the relationship between fish catches and sea-surface temperature, mixed-layer depth, and water color. The 1969 albacore season off the Pacific Northwest lasted for 67 days, from 12 July to 16 September. Nearly 30 million pounds of albacore, worth $6.7 million, were landed in Oregon ports, making 1969 the second best season in history. The first commercial quantities of albacore were caught about 135 n mi west of Coos Bay. During the rest of July the fish moved north somewhat but stayed well offshore. During August the fishery spread out considerably, moving as far north as Vancouver Island. In September fishing activity shifted south and inshore. Off the Pacific Northwest no albacore were taken from waters cooler than 54F(12.2C) or warmer than 66F(18.9C). Most fish were taken from the sea-surface temperature range of 59. 5-63.5F(15.3-17.5C). July fish favored 61.5-63.5F(16.4-17.5C) water. By contrast, August fish favored 59.5-63.5F(15.3-17.5C) water while September fish favored 59.5-61.5F(15.3-16.4C) water. Catch-per-unit- effort data did not indicate as marked a decline in availability at cooler temperatures as did gross catch. Mixed-layer depths associated with favorable albacore catches, 56-135 ft(17.1-41.1 m), were somewhat deeper than those determined by previous investigations. Water-color results showed that most albacore were caught in blue oceanic water. Other factors associated with good fishing included favorable wind and sea conditions, areas with considerable temperature structure, plentiful food supply, presence of "tuna birds", and stable, moderately developed upwelling situation. Title: Albacore tuna catches in the Northeast Pacific during summer 1969 as related to selected ocean conditions Author: Panshin, Daniel Alexis Oregon's commercial fishery for albacore tuna (Thunnus alalunga) is large, valuable, and variable. Little is known, however, about the oceanographic factors which determine abundance and distribution of albacore. Primarily using logbook data contributed by fishermen, this study compares albacore catches with selected ocean conditions. The study is limited to troll-caught fish taken during the summer of 1969 off the Pacific Northwest. The location and success of commercial albacore catches were analyzed with respect to the sea-surface temperature field. Also examined was the relationship between fish catches and sea-surface temperature, mixed-layer depth, and water color. The 1969 albacore season off the Pacific Northwest lasted for 67 days, from 12 July to 16 September. Nearly 30 million pounds of albacore, worth $6.7 million, were landed in Oregon ports, making 1969 the second best season in history. The first commercial quantities of albacore were caught about 135 n mi west of Coos Bay. During the rest of July the fish moved north somewhat but stayed well offshore. During August the fishery spread out considerably, moving as far north as Vancouver Island. In September fishing activity shifted south and inshore. Off the Pacific Northwest no albacore were taken from waters cooler than 54F(12.2C) or warmer than 66F(18.9C). Most fish were taken from the sea-surface temperature range of 59. 5-63.5F(15.3-17.5C). July fish favored 61.5-63.5F(16.4-17.5C) water. By contrast, August fish favored 59.5-63.5F(15.3-17.5C) water while September fish favored 59.5-61.5F(15.3-16.4C) water. Catch-per-unit- effort data did not indicate as marked a decline in availability at cooler temperatures as did gross catch. Mixed-layer depths associated with favorable albacore catches, 56-135 ft(17.1-41.1 m), were somewhat deeper than those determined by previous investigations. Water-color results showed that most albacore were caught in blue oceanic water. Other factors associated with good fishing included favorable wind and sea conditions, areas with considerable temperature structure, plentiful food supply, presence of "tuna birds", and stable, moderately developed upwelling situation. Close

• 2217. [Article] Historic fires in the central Western Cascades, Oregon

  The history of fire between 1850 and 1977 in a portion of the Willamette National Forest in-the central Western Cascades of Oregon was documented using historical sources. Three types of records were available: ...

  Citation × Citation Citation Abstract Copy Title: Historic fires in the central Western Cascades, Oregon Author: Burke, Constance J. The history of fire between 1850 and 1977 in a portion of the Willamette National Forest in-the central Western Cascades of Oregon was documented using historical sources. Three types of records were available: (1) records and writings not primarily concerned with fire but yielding information about fire in context with human activities, (2) descriptive accounts of fires prior to 1910, and (3) statistical reports generated by the U.S. Forest Service from 1910 to the present. Corresponding to each type of record, this study was divided into three time periods: pre-1850, 1850-1909, and 1910-1977. Information about the pre-1850 period was drawn from reconstructions of aboriginal forest use by anthropologists, archaeologists, and enthnographers. Although four groups of aboriginal people inhabited areas within or adjacent to the study area, evidence is lacking for intentional Indian burning in the central Western Cascades. Unintentional burning from untended or abandoned campfires is probable. Coupled with naturally occurring lightning-caused fires, these fires were ample ignition to maintain an age class of 125 years or older in the forests of the central Western Cascades. Information about fires occurring between 1850 and 1909 came from a variety of historic sources. All chronicled fires were attributed to man. Many man-caused fires were related to specific human activities, including road building, sheep grazing, and camping. As human use increased, the numbers of fires increased. Conflicts in use occurred because of the threat of fire. Some activities, such as mining and railroading, were not causes of fire in the central Western Cascades. Lightning was not regarded as a cause of forest fires until after 1900. Fire records for the period from 1910 to 1977 were generated by the U.S. Forest Service. These records exist in various forms including fire maps, summary tables, and individual fire reports. Almost 60 percent of all recorded fires from 1910 to 1977 were lightning caused. While lightning ignited more fires, they were usually small and occurred in mid-summer. Man-caused fires although fewer, were larger and occurred throughout the fire season. An increase in the number of fires is paralleled by an increase in forest use. Two maps were constructed to illustrate the spatial distribution of man-caused and lightning-caused fires. Lightning-caused fires appear to be unevenly distributed over the landscape. Three areas exhibit a low incidence of lightning-caused fires. Lightning fires occur at higher elevations, where fuel accumulations are less, and tend to remain small. Man-caused fires exhibit a definite pattern corresponding with land-use. These fires tend to follow major transportation routes which are generally at lower elevations. Man-caused fires, ignited at lower elevations, have more chance to spread and become large fires. Title: Historic fires in the central Western Cascades, Oregon Author: Burke, Constance J. The history of fire between 1850 and 1977 in a portion of the Willamette National Forest in-the central Western Cascades of Oregon was documented using historical sources. Three types of records were available: (1) records and writings not primarily concerned with fire but yielding information about fire in context with human activities, (2) descriptive accounts of fires prior to 1910, and (3) statistical reports generated by the U.S. Forest Service from 1910 to the present. Corresponding to each type of record, this study was divided into three time periods: pre-1850, 1850-1909, and 1910-1977. Information about the pre-1850 period was drawn from reconstructions of aboriginal forest use by anthropologists, archaeologists, and enthnographers. Although four groups of aboriginal people inhabited areas within or adjacent to the study area, evidence is lacking for intentional Indian burning in the central Western Cascades. Unintentional burning from untended or abandoned campfires is probable. Coupled with naturally occurring lightning-caused fires, these fires were ample ignition to maintain an age class of 125 years or older in the forests of the central Western Cascades. Information about fires occurring between 1850 and 1909 came from a variety of historic sources. All chronicled fires were attributed to man. Many man-caused fires were related to specific human activities, including road building, sheep grazing, and camping. As human use increased, the numbers of fires increased. Conflicts in use occurred because of the threat of fire. Some activities, such as mining and railroading, were not causes of fire in the central Western Cascades. Lightning was not regarded as a cause of forest fires until after 1900. Fire records for the period from 1910 to 1977 were generated by the U.S. Forest Service. These records exist in various forms including fire maps, summary tables, and individual fire reports. Almost 60 percent of all recorded fires from 1910 to 1977 were lightning caused. While lightning ignited more fires, they were usually small and occurred in mid-summer. Man-caused fires although fewer, were larger and occurred throughout the fire season. An increase in the number of fires is paralleled by an increase in forest use. Two maps were constructed to illustrate the spatial distribution of man-caused and lightning-caused fires. Lightning-caused fires appear to be unevenly distributed over the landscape. Three areas exhibit a low incidence of lightning-caused fires. Lightning fires occur at higher elevations, where fuel accumulations are less, and tend to remain small. Man-caused fires exhibit a definite pattern corresponding with land-use. These fires tend to follow major transportation routes which are generally at lower elevations. Man-caused fires, ignited at lower elevations, have more chance to spread and become large fires. Close

• 2218. [Article] Habitat relationships of native and non-native fishes of the Willamette River, Oregon

  The Willamette River flows north between the Cascade Mountains and Coast Range of western Oregon within a 29,728-km² basin. The fish community in the geologically young basin consists of 36 native species, ...

  Citation × Citation Citation Abstract Copy Title: Habitat relationships of native and non-native fishes of the Willamette River, Oregon Author: Williams, Joshua E. (Joshua Everett) The Willamette River flows north between the Cascade Mountains and Coast Range of western Oregon within a 29,728-km² basin. The fish community in the geologically young basin consists of 36 native species, but introductions of non-native fishes have added 33 additional species for a total of 69 fish species. During the summers of 2011-2013, fish distributions were sampled from the confluence of the McKenzie River downstream to the confluence of the Columbia River to assess: (1) fish community composition, (2) differences in community composition between mainstem river and slough habitats, and (3) relationships between native and non-native fish species and physical habitat characteristics. In addition, a 182-ha seasonally inundated floodplain habitat along the middle Willamette River was sampled during winter 2011 through spring 2012 to assess: (1) fish community composition, (2) spawning and rearing, and (3) timing of use and movement by fish species. Throughout the three years of longitudinal sampling, 36,586 fish were collected comprising 41 species, 22 native and 19 non-native. Overall, native fish represented 93% of the total fish sampled. Higher numbers of fish were collected in the upper river, and higher proportions of those fish were native species. Though non-native fish were more common in slough habitats than mainstem sties, the majority of fish collected in both habitat types were native. The strongest environmental predictors of fish community were quantitative measures of longitudinal distance, velocity, depth, percent macrophyte cover and percent embeddedness. Habitat type (slough versus mainstem) was also a significant predictor. Native fish species exhibited greater variability in habitat relationships than non-native fishes, though several native species were strongly associated with specific environmental attributes. Non-native species were more associated with slough habitats and sites with high amount of macrophyte growth and embedded substrates. Overall, 25 species had a high fidelity to mainstem or slough habitats. Equal numbers of native species showed a fidelity to either mainstem or slough sites, but non-native species were significantly related only to slough habitats. In the seasonally inundated floodplain habitat, an estimated 43,000 fish were collected comprising 23 species; 12 native and 11 non-native. Of these 98.1% were native. The most common native species were threespine stickleback Gasterosteus aculeatus and peamouth Mylocheilus caurinus while the most common non-native species were bluegill Lepomis macrochirus and western mosquitofish Gambusia affinus. Several species used the inundated floodplain for spawning and rearing, particularly threespine stickleback, peamouth and western mosquitofish. With the exception of young-of-year threespine stickleback, native species were collected mostly in the beginning and middle of the sampling period while non-native species were collected in the latter portion of the sampling. The Willamette River Basin has a long history of environmental modification. Understanding relationships of a broad range of species to their environment and to each other provides a technical foundation for ecosystem based management by state and federal agencies, local municipalities, and private landowners. The need for ecosystem based management is vital for future conservation and recovery of large river floodplain ecosystems. Title: Habitat relationships of native and non-native fishes of the Willamette River, Oregon Author: Williams, Joshua E. (Joshua Everett) The Willamette River flows north between the Cascade Mountains and Coast Range of western Oregon within a 29,728-km² basin. The fish community in the geologically young basin consists of 36 native species, but introductions of non-native fishes have added 33 additional species for a total of 69 fish species. During the summers of 2011-2013, fish distributions were sampled from the confluence of the McKenzie River downstream to the confluence of the Columbia River to assess: (1) fish community composition, (2) differences in community composition between mainstem river and slough habitats, and (3) relationships between native and non-native fish species and physical habitat characteristics. In addition, a 182-ha seasonally inundated floodplain habitat along the middle Willamette River was sampled during winter 2011 through spring 2012 to assess: (1) fish community composition, (2) spawning and rearing, and (3) timing of use and movement by fish species. Throughout the three years of longitudinal sampling, 36,586 fish were collected comprising 41 species, 22 native and 19 non-native. Overall, native fish represented 93% of the total fish sampled. Higher numbers of fish were collected in the upper river, and higher proportions of those fish were native species. Though non-native fish were more common in slough habitats than mainstem sties, the majority of fish collected in both habitat types were native. The strongest environmental predictors of fish community were quantitative measures of longitudinal distance, velocity, depth, percent macrophyte cover and percent embeddedness. Habitat type (slough versus mainstem) was also a significant predictor. Native fish species exhibited greater variability in habitat relationships than non-native fishes, though several native species were strongly associated with specific environmental attributes. Non-native species were more associated with slough habitats and sites with high amount of macrophyte growth and embedded substrates. Overall, 25 species had a high fidelity to mainstem or slough habitats. Equal numbers of native species showed a fidelity to either mainstem or slough sites, but non-native species were significantly related only to slough habitats. In the seasonally inundated floodplain habitat, an estimated 43,000 fish were collected comprising 23 species; 12 native and 11 non-native. Of these 98.1% were native. The most common native species were threespine stickleback Gasterosteus aculeatus and peamouth Mylocheilus caurinus while the most common non-native species were bluegill Lepomis macrochirus and western mosquitofish Gambusia affinus. Several species used the inundated floodplain for spawning and rearing, particularly threespine stickleback, peamouth and western mosquitofish. With the exception of young-of-year threespine stickleback, native species were collected mostly in the beginning and middle of the sampling period while non-native species were collected in the latter portion of the sampling. The Willamette River Basin has a long history of environmental modification. Understanding relationships of a broad range of species to their environment and to each other provides a technical foundation for ecosystem based management by state and federal agencies, local municipalities, and private landowners. The need for ecosystem based management is vital for future conservation and recovery of large river floodplain ecosystems. Close

• 2219. [Article] Novel characteristics (Intra and Ex planta) of indigenous serogroups of rhizobium meliloti

  This thesis presents novel findings regarding symbiotic, physiological, and antigenic characteristics of representatives from an indigenous soil-borne population of Rhizobium meliloti. Nodules were sampled ...

  Citation × Citation Citation Abstract Copy Title: Novel characteristics (Intra and Ex planta) of indigenous serogroups of rhizobium meliloti Author: Busse, Matt D. This thesis presents novel findings regarding symbiotic, physiological, and antigenic characteristics of representatives from an indigenous soil-borne population of Rhizobium meliloti. Nodules were sampled from 'Vernal', 'Anchor', and 'Saranac' alfalfa, and the isolates analyzed serologically. Rhizobium meliloti serogroup 31 was identified as a dominant nodule occupant, with a greater and more consistent nodule occupancy rate on Vernal (60%) compared to Anchor (24%) or Saranac (36%). The symbiotic effectiveness of the parent isolate of serogroup 31 was evaluated on each cultivar over four harvests in a greenhouse study. Only inoculated Vernal responded with an increase in shoot dry weight and N₂ assimilated relative to N supplemented plants between harvests two and three. Field isolates of serogroup 31 from nodules on Vernal produced homogeneous, effective responses on Vernal and Anchor. In contrast, serogroup 31 isolates from Anchor nodules were heterogeneous in effectiveness on the parent host, with poorly effective isolates shown to be substantially more effective on Vernal. Isolates of Rhizobium meliloti serogroups 31 and 17 were grown in yeast extract mannitol broth (YEM) containing NaCl or polyethylene glycol (PEG). At water potentials below -0.5 MPa imposed by PEG, strain 31 had a lower specific growth rate than strain 17 which was accompanied by irregular cell morphology. In contrast, neither strain was affected significantly over the range of water potentials created by NaCl. Upshock of water stressed cells (-1.0 MPa PEG) into normal YEM (-0.15 MPa) resulted in a faster recovery of growth by strain 31 than strain 17. Strain 31 also required significantly fewer days to nodulate alfalfa compared with strain 17 when transferred from YEM at -1.0 MPa PEG onto the roots of alfalfa seedlings in plant growth medium (-0.1 MPa). Supplemental calcium (O.lmM) reduced the differences between strains in their response to water stress. Several novel phenomena were shown to hinder the production of fluorescent antibody conjugates specific to serogroup 31. An indirect fluorescent methodology, using the biotin-avidin system, was developed to successfully detect and specifically discriminate members of serogroup 31 from other strains of R. meliloti. Using this technique, members of serogroup 31 were found to comprise 17% of the total R. meliloti population in soil samples with a recent history of alfalfa cultivation. Title: Novel characteristics (Intra and Ex planta) of indigenous serogroups of rhizobium meliloti Author: Busse, Matt D. This thesis presents novel findings regarding symbiotic, physiological, and antigenic characteristics of representatives from an indigenous soil-borne population of Rhizobium meliloti. Nodules were sampled from 'Vernal', 'Anchor', and 'Saranac' alfalfa, and the isolates analyzed serologically. Rhizobium meliloti serogroup 31 was identified as a dominant nodule occupant, with a greater and more consistent nodule occupancy rate on Vernal (60%) compared to Anchor (24%) or Saranac (36%). The symbiotic effectiveness of the parent isolate of serogroup 31 was evaluated on each cultivar over four harvests in a greenhouse study. Only inoculated Vernal responded with an increase in shoot dry weight and N₂ assimilated relative to N supplemented plants between harvests two and three. Field isolates of serogroup 31 from nodules on Vernal produced homogeneous, effective responses on Vernal and Anchor. In contrast, serogroup 31 isolates from Anchor nodules were heterogeneous in effectiveness on the parent host, with poorly effective isolates shown to be substantially more effective on Vernal. Isolates of Rhizobium meliloti serogroups 31 and 17 were grown in yeast extract mannitol broth (YEM) containing NaCl or polyethylene glycol (PEG). At water potentials below -0.5 MPa imposed by PEG, strain 31 had a lower specific growth rate than strain 17 which was accompanied by irregular cell morphology. In contrast, neither strain was affected significantly over the range of water potentials created by NaCl. Upshock of water stressed cells (-1.0 MPa PEG) into normal YEM (-0.15 MPa) resulted in a faster recovery of growth by strain 31 than strain 17. Strain 31 also required significantly fewer days to nodulate alfalfa compared with strain 17 when transferred from YEM at -1.0 MPa PEG onto the roots of alfalfa seedlings in plant growth medium (-0.1 MPa). Supplemental calcium (O.lmM) reduced the differences between strains in their response to water stress. Several novel phenomena were shown to hinder the production of fluorescent antibody conjugates specific to serogroup 31. An indirect fluorescent methodology, using the biotin-avidin system, was developed to successfully detect and specifically discriminate members of serogroup 31 from other strains of R. meliloti. Using this technique, members of serogroup 31 were found to comprise 17% of the total R. meliloti population in soil samples with a recent history of alfalfa cultivation. Close

• 2220. [Article] Field practices as bases for evaluating and improving a college-level air-conditioning drafting course

  This study deals primarily with the evaluation and improvement of the content of a college-level drafting course for air conditioning engineering students. The necessity for better integration of the mechanical and ...

  Citation × Citation Citation Abstract Copy Title: Field practices as bases for evaluating and improving a college-level air-conditioning drafting course Author: Graves, Theodore George This study deals primarily with the evaluation and improvement of the content of a college-level drafting course for air conditioning engineering students. The necessity for better integration of the mechanical and architectural elements contained in the course, and an adequate coverage of field drafting room practices were the chief evidences of the need for the study. The purpose of this study was to develop criteria that could be used to evaluate and improve said drafting course; and the end result was manifested by an improved proposed drafting course, which was included in the Appendix. The study was conducted in the Los Angeles Metropolitan Area. Eighteen carefully selected air conditioning and refrigeration firms were interviewed to determine the per cent frequency of occurrence of selected field drafting room practices. This group represented contracting firms, consulting engineering offices, controls companies, and manufacturing firms. Chapter II presents a brief history of the development of the air conditioning and refrigeration industry. Special attention was given to the contemporary applications and to the need for specialized training on a college level. The collected field data was tabulated, analyzed and classified in Chapter III. This field data represented percent frequency of occurrence responses concerning drafting room practices covering the following nine general areas: (1) floor plans; (2) duct work; (3) piping drawings; (4) controls; (5) equipment rooms; (6) manufacturing; (7) sketching; (8) drafting techniques; and (9) drafting material. Five orders of classification were established: (1) standard practices; (2) common practices; (3) occasional practices; (4) infrequent practices; and (5) obsolete practices. Chapter IV contains the summary, conclusions and recommendations. The conclusions reached the were as follows: (1) ranked practices can be used as an evaluative instrument; (2) greater weight should be given to standard end common field and area practices; (3) many occasional and infrequent practices are essential practices in the individual firms concerned; (4) practices with broad general concepts should be used as instructional vehicles; (5) a degree of standardization of drafting practices has taken place; (6) a few of the practices have become obsolete; (7) the comprehension of control circuits is beyond most freshmen; (8) there is a trend toward more manufacturing in the area investigated; and (9) sketching ability is highly desirable. It was recommended that the course should be so organized as to bring about the following general outcomes: An understanding of and the ability to apply basic drafting techniques and practices as defined by the A.S.A., and also of those common to the selected field. The following specific recommendations were also made: (1) floor plans drawn, using conventional architectural symbols; (2) two-line duct systems drawn, using field techniques; (3) lettering style should progress from formal to a modified style; (4) piping systems drawn in isometric and orthographic, using a single-line diagrammatic form; (5) no control system; (6) equipment rooms drawn with "blocked" equipment shown; (7) manufacturing drawings developed; (8) improvement of sketching ability; (9) maintenance of the highest drafting standards; (10) use of drafting equipment common to the field; and (11) the inclusion of some sheet metal pattern development. Title: Field practices as bases for evaluating and improving a college-level air-conditioning drafting course Author: Graves, Theodore George This study deals primarily with the evaluation and improvement of the content of a college-level drafting course for air conditioning engineering students. The necessity for better integration of the mechanical and architectural elements contained in the course, and an adequate coverage of field drafting room practices were the chief evidences of the need for the study. The purpose of this study was to develop criteria that could be used to evaluate and improve said drafting course; and the end result was manifested by an improved proposed drafting course, which was included in the Appendix. The study was conducted in the Los Angeles Metropolitan Area. Eighteen carefully selected air conditioning and refrigeration firms were interviewed to determine the per cent frequency of occurrence of selected field drafting room practices. This group represented contracting firms, consulting engineering offices, controls companies, and manufacturing firms. Chapter II presents a brief history of the development of the air conditioning and refrigeration industry. Special attention was given to the contemporary applications and to the need for specialized training on a college level. The collected field data was tabulated, analyzed and classified in Chapter III. This field data represented percent frequency of occurrence responses concerning drafting room practices covering the following nine general areas: (1) floor plans; (2) duct work; (3) piping drawings; (4) controls; (5) equipment rooms; (6) manufacturing; (7) sketching; (8) drafting techniques; and (9) drafting material. Five orders of classification were established: (1) standard practices; (2) common practices; (3) occasional practices; (4) infrequent practices; and (5) obsolete practices. Chapter IV contains the summary, conclusions and recommendations. The conclusions reached the were as follows: (1) ranked practices can be used as an evaluative instrument; (2) greater weight should be given to standard end common field and area practices; (3) many occasional and infrequent practices are essential practices in the individual firms concerned; (4) practices with broad general concepts should be used as instructional vehicles; (5) a degree of standardization of drafting practices has taken place; (6) a few of the practices have become obsolete; (7) the comprehension of control circuits is beyond most freshmen; (8) there is a trend toward more manufacturing in the area investigated; and (9) sketching ability is highly desirable. It was recommended that the course should be so organized as to bring about the following general outcomes: An understanding of and the ability to apply basic drafting techniques and practices as defined by the A.S.A., and also of those common to the selected field. The following specific recommendations were also made: (1) floor plans drawn, using conventional architectural symbols; (2) two-line duct systems drawn, using field techniques; (3) lettering style should progress from formal to a modified style; (4) piping systems drawn in isometric and orthographic, using a single-line diagrammatic form; (5) no control system; (6) equipment rooms drawn with "blocked" equipment shown; (7) manufacturing drawings developed; (8) improvement of sketching ability; (9) maintenance of the highest drafting standards; (10) use of drafting equipment common to the field; and (11) the inclusion of some sheet metal pattern development. Close