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• 111. [Article] Continuous Flow Synthesis of Ceria Nanoparticles Using Static T-mixers

  This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/chemical-engine...

  Citation × Citation Citation Abstract Copy Title: Continuous Flow Synthesis of Ceria Nanoparticles Using Static T-mixers Author: Paul, Brian, Palanisamy, Barath This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/chemical-engineering-science/. Title: Continuous Flow Synthesis of Ceria Nanoparticles Using Static T-mixers Author: Paul, Brian, Palanisamy, Barath This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/chemical-engineering-science/. Close

• 112. [Article] Image-Seeking Preferences Among Undergraduate Novice Researchers

  Objective – This study investigated the image-seeking preferences of university freshmen to gain a better understanding of how they search for pictures for assignments. Methods – A survey was emailed ...

  Citation × Citation Citation Abstract Copy Title: Image-Seeking Preferences Among Undergraduate Novice Researchers Author: Edmunson-Morton, Tiah, Bridges, Laurie Objective – This study investigated the image-seeking preferences of university freshmen to gain a better understanding of how they search for pictures for assignments. Methods – A survey was emailed to a random sample of 1,000 freshmen enrolled at Oregon State University in the fall of 2009. A total of 63 surveys were returned. Results – The majority of students indicated they would use Google to find a picture. Nineteen respondents said they would use a library, librarians, and/or archives. Conclusions – The results indicate the majority of students in our study would use Google to find an image for coursework purposes; yet the students who suggested they would use Google did not mention evaluating the images they might find or have concerns about copyright issues. Undergraduate students would benefit from having visual literacy integrated into standard information literacy instruction to help them locate, evaluate, and legally use the images they find online. In addition, libraries, librarians, archivists, and library computer programmers should work to raise the rankings of library digital photo collections in online search engines like Google. Title: Image-Seeking Preferences Among Undergraduate Novice Researchers Author: Edmunson-Morton, Tiah, Bridges, Laurie Objective – This study investigated the image-seeking preferences of university freshmen to gain a better understanding of how they search for pictures for assignments. Methods – A survey was emailed to a random sample of 1,000 freshmen enrolled at Oregon State University in the fall of 2009. A total of 63 surveys were returned. Results – The majority of students indicated they would use Google to find a picture. Nineteen respondents said they would use a library, librarians, and/or archives. Conclusions – The results indicate the majority of students in our study would use Google to find an image for coursework purposes; yet the students who suggested they would use Google did not mention evaluating the images they might find or have concerns about copyright issues. Undergraduate students would benefit from having visual literacy integrated into standard information literacy instruction to help them locate, evaluate, and legally use the images they find online. In addition, libraries, librarians, archivists, and library computer programmers should work to raise the rankings of library digital photo collections in online search engines like Google. Close

• 113. [Article] Evaluation of the Douglas-fir beetle infestation in the North Fork Clearwater River drainage, Idaho--1972

  The Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., has caused extensive tree mortality for the third consecutive year in the North Fork Clearwater River drainage in northern Idaho. In 1972, the ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of the Douglas-fir beetle infestation in the North Fork Clearwater River drainage, Idaho--1972 Author: McGregor, Mark D., Bousfield, Wayne E., United States. Forest Service. Northern Region. State & Private Forestry The Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., has caused extensive tree mortality for the third consecutive year in the North Fork Clearwater River drainage in northern Idaho. In 1972, the infestation encompassed about 494,080 acres of commercial forest lands in this drainage. It was estimated from a tw-stage aerial photo-ground survey that 240,00 trees were killed during the 3-year period 1970-72, resulting in a loss of about 109 MMBF of Douglas-fir sawtimber. Infestation levels are expected to decline in 1973, but significant tree mortality is expected in Localized infestation centers. Title: Evaluation of the Douglas-fir beetle infestation in the North Fork Clearwater River drainage, Idaho--1972 Author: McGregor, Mark D., Bousfield, Wayne E., United States. Forest Service. Northern Region. State & Private Forestry The Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., has caused extensive tree mortality for the third consecutive year in the North Fork Clearwater River drainage in northern Idaho. In 1972, the infestation encompassed about 494,080 acres of commercial forest lands in this drainage. It was estimated from a tw-stage aerial photo-ground survey that 240,00 trees were killed during the 3-year period 1970-72, resulting in a loss of about 109 MMBF of Douglas-fir sawtimber. Infestation levels are expected to decline in 1973, but significant tree mortality is expected in Localized infestation centers. Close

• 114. [Article] Beyond Foursquare: Library Treks with SCVNGR

  SCVNGR is a game-based geolocation application where users can earn points or gain rewards by completing challenges and treks. Builders design questions that involve text based answers (open ended or multiple ...

  Citation × Citation Citation Abstract Copy Title: Beyond Foursquare: Library Treks with SCVNGR Author: Mellinger, Margaret, Vecchione, Amy E. SCVNGR is a game-based geolocation application where users can earn points or gain rewards by completing challenges and treks. Builders design questions that involve text based answers (open ended or multiple choice), QR codes, or photo challenges. Librarians at Boise State University and Oregon State University have built treks and challenges using SCVNGR for library orientations and instruction. They have found SCVNGR a better environment than Foursquare for these purposes. With SCVNGR, students can participate in the challenges and treks using not only their smart phones and mobile devices, but also via text-messaging and laptops. Librarians can easily create multiple places within a single building or location, facilitating tours within a library space. In addition, SCVNGR is amenable to working with universities and libraries. Participants will gain an introduction to SCVNGR, discover how to use SCVNGR in their own library environment, and learn how these universities have utilized SCVNGR successfully Title: Beyond Foursquare: Library Treks with SCVNGR Author: Mellinger, Margaret, Vecchione, Amy E. SCVNGR is a game-based geolocation application where users can earn points or gain rewards by completing challenges and treks. Builders design questions that involve text based answers (open ended or multiple choice), QR codes, or photo challenges. Librarians at Boise State University and Oregon State University have built treks and challenges using SCVNGR for library orientations and instruction. They have found SCVNGR a better environment than Foursquare for these purposes. With SCVNGR, students can participate in the challenges and treks using not only their smart phones and mobile devices, but also via text-messaging and laptops. Librarians can easily create multiple places within a single building or location, facilitating tours within a library space. In addition, SCVNGR is amenable to working with universities and libraries. Participants will gain an introduction to SCVNGR, discover how to use SCVNGR in their own library environment, and learn how these universities have utilized SCVNGR successfully Close

• 115. [Article] “SeW: A Search for Selenosulfide Bonding” and “Severity of Damage Inflicted on Intercellular Disulfide Bonds as a Result of UV Radiation”

  Part 1: White muscle disease (WMD), a degenerative muscle disease brought on by a deficiency of the essential trace nutrient selenium, is thought to be mediated by the protein Selenoprotein W (SeW). In ...

  Citation × Citation Citation Abstract Copy Title: “SeW: A Search for Selenosulfide Bonding” and “Severity of Damage Inflicted on Intercellular Disulfide Bonds as a Result of UV Radiation” Author: Dutcher, Kendall Part 1: White muscle disease (WMD), a degenerative muscle disease brought on by a deficiency of the essential trace nutrient selenium, is thought to be mediated by the protein Selenoprotein W (SeW). In its relationship with WMD, SeW, like many selenoproteins, binds to glutathione, serving some purpose in redox mechanisms in rats and in vivo. Recognizing that the protein may selectively bind glutathione and that it may be a glutathione-dependent in-vivo antioxidant, it has been proposed by Bauman (2004) that SeW has a mechanism involving reducing activity, much like that of thioredoxin reductase. This and the presence of selenocysteine in SeW suggest that there may be intramolecular disulfide/selenosulfide bonds being formed in the N-terminal region (this region contains Y-C-G-A-SeC or CXXSeC). Investigation into the possible presence of disulfide bonds in the non-native form of SeW, using elctrophoresis and MALDI-MS/MS, strongly suggest that there is a disulfide bond in the N-terminal region. A similar investigation into the presence of a selenosulfide bond in the native form of SeW, using samples isolated in the Bauman study, was inconclusive, due to the possible lack/low concentration of protein in the original samples (<10-100fmol), its possibly degraded state, or inappropriate procedure for analyzing the protein. It is still supposed that there is a selenosulfide bond in the N-terminal region of the native SeW, as in the non-native form, but until there is a sufficient amount of the protein to work with, this hypothesis cannot be tested. Part 2: High-energy radiation damage in biological macromolecules is responsible for diseases, aging, and impairment of vital biological functions. The radiation itself may be directly responsible for only part of the damage, though. Damage caused by intermediate species created within nanoscopic volumes along the ionization tracks can be far more significant because of the chemical reactions that follow. The intermediate species may consist of excited atoms and molecules, ions, radicals, and most importantly secondary electrons that are produced in very high abundance (>104 by a 1MeV projectile). Although much is known about secondary electrons and their interaction with DNA, little is known about the effect of such electrons on proteins even though interaction with secondary electrons resulting from irradiation is probable. In the case of caractacts, secondary electrons have been shown to cause a shuffling of disulfide linkages in lens proteins, which may undergo reduction by capture of low energy electrons then reoxidize forming non-native disulfides. A preliminary study was proposed, using Glutatione (GSH and GSSG, 100uM) as a model, which looked into the effects of secondary electrons on proteins with disulfide bonds, using varying levels (0-6.4kJ/m2) of UVB and UVC radiation, a DTNB assay, and HPLC-ESI-MS/MS. As the energy was increased step-wise (0-6.4kJ/m2), a 9.5±1.3% and 8.8±2.1% decrease in GSH activity was observed for 254nm and 365nm, respectively. This decrease could be from photo-oxidation. As the energy was increased step-wise from 0-32 MEDS (0-672 mJ/cm2), an increase of over 1uM was seen at 254nm. This increase could be a product of photolysis or photo reduction. To confirm assay findings, HPLC-ESI-MS/MS was attempted, but separation of the GSSG and GSH(-NEM) species could not be achieved and results were subsequently inconclusive. Title: “SeW: A Search for Selenosulfide Bonding” and “Severity of Damage Inflicted on Intercellular Disulfide Bonds as a Result of UV Radiation” Author: Dutcher, Kendall Part 1: White muscle disease (WMD), a degenerative muscle disease brought on by a deficiency of the essential trace nutrient selenium, is thought to be mediated by the protein Selenoprotein W (SeW). In its relationship with WMD, SeW, like many selenoproteins, binds to glutathione, serving some purpose in redox mechanisms in rats and in vivo. Recognizing that the protein may selectively bind glutathione and that it may be a glutathione-dependent in-vivo antioxidant, it has been proposed by Bauman (2004) that SeW has a mechanism involving reducing activity, much like that of thioredoxin reductase. This and the presence of selenocysteine in SeW suggest that there may be intramolecular disulfide/selenosulfide bonds being formed in the N-terminal region (this region contains Y-C-G-A-SeC or CXXSeC). Investigation into the possible presence of disulfide bonds in the non-native form of SeW, using elctrophoresis and MALDI-MS/MS, strongly suggest that there is a disulfide bond in the N-terminal region. A similar investigation into the presence of a selenosulfide bond in the native form of SeW, using samples isolated in the Bauman study, was inconclusive, due to the possible lack/low concentration of protein in the original samples (<10-100fmol), its possibly degraded state, or inappropriate procedure for analyzing the protein. It is still supposed that there is a selenosulfide bond in the N-terminal region of the native SeW, as in the non-native form, but until there is a sufficient amount of the protein to work with, this hypothesis cannot be tested. Part 2: High-energy radiation damage in biological macromolecules is responsible for diseases, aging, and impairment of vital biological functions. The radiation itself may be directly responsible for only part of the damage, though. Damage caused by intermediate species created within nanoscopic volumes along the ionization tracks can be far more significant because of the chemical reactions that follow. The intermediate species may consist of excited atoms and molecules, ions, radicals, and most importantly secondary electrons that are produced in very high abundance (>104 by a 1MeV projectile). Although much is known about secondary electrons and their interaction with DNA, little is known about the effect of such electrons on proteins even though interaction with secondary electrons resulting from irradiation is probable. In the case of caractacts, secondary electrons have been shown to cause a shuffling of disulfide linkages in lens proteins, which may undergo reduction by capture of low energy electrons then reoxidize forming non-native disulfides. A preliminary study was proposed, using Glutatione (GSH and GSSG, 100uM) as a model, which looked into the effects of secondary electrons on proteins with disulfide bonds, using varying levels (0-6.4kJ/m2) of UVB and UVC radiation, a DTNB assay, and HPLC-ESI-MS/MS. As the energy was increased step-wise (0-6.4kJ/m2), a 9.5±1.3% and 8.8±2.1% decrease in GSH activity was observed for 254nm and 365nm, respectively. This decrease could be from photo-oxidation. As the energy was increased step-wise from 0-32 MEDS (0-672 mJ/cm2), an increase of over 1uM was seen at 254nm. This increase could be a product of photolysis or photo reduction. To confirm assay findings, HPLC-ESI-MS/MS was attempted, but separation of the GSSG and GSH(-NEM) species could not be achieved and results were subsequently inconclusive. Close

• 116. [Article] Induction of diapause in Colladonus montanus reductus (Van Duze)

  Experiments conducted in the greenhouse showed that the leafhopper, Colladonus montanus reductus (Van Duzee), is a long-day insect. This conclusion is based on the production of diapausing eggs when the ...

  Citation × Citation Citation Abstract Copy Title: Induction of diapause in Colladonus montanus reductus (Van Duze) Author: Marsh, Terrence George Experiments conducted in the greenhouse showed that the leafhopper, Colladonus montanus reductus (Van Duzee), is a long-day insect. This conclusion is based on the production of diapausing eggs when the leafhoppers were kept under short days (ten hours) during the nymphal stage and the adult pre-oviposition period. Continuous development of generations occurred when insects were kept under long days (16 hours) during the nymphal stages and the adult pre-oviposition period. The effect of short days during the nymphal stages could be reversed if the nymphs were transferred to long days as they became adults; few diapausing eggs were produced under these conditions. The effect of long days during the nymphal stages was only slightly altered if the nymphs were transferred to short days as they became adults; very few, if any, diapausing eggs were produced. Embryos in diapause appeared to be in the anatrepsis stage of development; segmentation was taking place insofar as buds of future legs and mouthparts could be seen. Females deposited the majority of their eggs in the leaves of Trifolium subterraneum L., regardless of the combinations of photo-periods that they had experienced during their life cycles. Very few, if any, eggs were laid in the basal portions of the plants by adults that spent all of their life cycle under the 16-hour photoperiod. Females that spent part or all of their life cycle under the ten-hour photoperiod laid significantly greater percentages of their eggs in the basal portions of the plants than females that spent all of their life cycle under the 16-hour photoperiod. I suggested that diapausing eggs laid in the basal portions of the plants would be better protected from injury and dessication during the winter. In general, adult leafhoppers that were reared as nymphs under eight-hour or ten-hour photoperiods were somewhat lighter in color than adults reared under a 16-hour photoperiod. Males were usually black and females were usually brown, although the color variation was such that the darkest females were about as dark as the color of the lightest males. The sexual dichromatism was much more striking than the seasonal dichromatism. Adults reared as nymphs under ten-hour and 16-hour photo-periods did not vary significantly in length when each sex was compared separately in one of the experiments. In another experiment, females reared under an eight-hour photoperiod were significantly shorter than females reared under a 16-hour photoperiod. Similarly, males reared under the eight-hour photoperiods were significantly shorter. I suggested that the significant difference in the latter experiment was due to the poor vigor of the plants that the nymphs fed on under the eight-hour photoperiod, rather than to a direct influence of the photoperiod on the leafhoppers. Title: Induction of diapause in Colladonus montanus reductus (Van Duze) Author: Marsh, Terrence George Experiments conducted in the greenhouse showed that the leafhopper, Colladonus montanus reductus (Van Duzee), is a long-day insect. This conclusion is based on the production of diapausing eggs when the leafhoppers were kept under short days (ten hours) during the nymphal stage and the adult pre-oviposition period. Continuous development of generations occurred when insects were kept under long days (16 hours) during the nymphal stages and the adult pre-oviposition period. The effect of short days during the nymphal stages could be reversed if the nymphs were transferred to long days as they became adults; few diapausing eggs were produced under these conditions. The effect of long days during the nymphal stages was only slightly altered if the nymphs were transferred to short days as they became adults; very few, if any, diapausing eggs were produced. Embryos in diapause appeared to be in the anatrepsis stage of development; segmentation was taking place insofar as buds of future legs and mouthparts could be seen. Females deposited the majority of their eggs in the leaves of Trifolium subterraneum L., regardless of the combinations of photo-periods that they had experienced during their life cycles. Very few, if any, eggs were laid in the basal portions of the plants by adults that spent all of their life cycle under the 16-hour photoperiod. Females that spent part or all of their life cycle under the ten-hour photoperiod laid significantly greater percentages of their eggs in the basal portions of the plants than females that spent all of their life cycle under the 16-hour photoperiod. I suggested that diapausing eggs laid in the basal portions of the plants would be better protected from injury and dessication during the winter. In general, adult leafhoppers that were reared as nymphs under eight-hour or ten-hour photoperiods were somewhat lighter in color than adults reared under a 16-hour photoperiod. Males were usually black and females were usually brown, although the color variation was such that the darkest females were about as dark as the color of the lightest males. The sexual dichromatism was much more striking than the seasonal dichromatism. Adults reared as nymphs under ten-hour and 16-hour photo-periods did not vary significantly in length when each sex was compared separately in one of the experiments. In another experiment, females reared under an eight-hour photoperiod were significantly shorter than females reared under a 16-hour photoperiod. Similarly, males reared under the eight-hour photoperiods were significantly shorter. I suggested that the significant difference in the latter experiment was due to the poor vigor of the plants that the nymphs fed on under the eight-hour photoperiod, rather than to a direct influence of the photoperiod on the leafhoppers. Close

• 117. [Article] Spatial pattern and dynamics of hardwood patches in the Coast Range of Oregon, 1939-1993

  Analysis of the long-term spatial pattern and dynamics of hardwood patches in the Coast Range of Oregon provides numerous ecological insights. Natural and anthropogenic disturbances have contributed to ...

  Citation × Citation Citation Abstract Copy Title: Spatial pattern and dynamics of hardwood patches in the Coast Range of Oregon, 1939-1993 Author: Hess, Rebecca Susan Analysis of the long-term spatial pattern and dynamics of hardwood patches in the Coast Range of Oregon provides numerous ecological insights. Natural and anthropogenic disturbances have contributed to the development of a patchy mosaic of vegetation types in the area. Some hardwood patches in the Coast Range may be the precursors to stable vegetation states. The five objectives for the study were to: 1) develop the methodology for studying patch dynamics at landscape scales; 2) describe changes in the areal extent and occurrence of hardwood patches; 3) characterize the sizes and shapes, and size and shape changes of hardwood patches in the west-central Coast Range of Oregon; 4) describe the shift in within-patch heterogeneity and within-patch vegetation composition features of hardwood patches; and 5) characterize patches occurring in riparian areas. A viable methodology was developed for the detailed study of the change in vegetation patches across landscapes using scanned, georeferenced aerial photos, aerial photo interpretation of hardwood patches, and GIS techniques. Patch locations and characteristics were compared to a suite of environmental and other variables. The hardwood patch mosaic was not a stable landscape feature. The total area covered by hardwood patches, the weighted mean size of hardwood patches, and the number of patches sampled declined from 1939 to 1993. Forest Service lands showed the most dramatic drop in hardwood area, while private non-industrial lands showed the most dramatic increase in hardwood area. Most patches present in 1939 either disappeared or decreased in size. In 1993, hardwood patches were found closer to streams and on lower slope positions than in 1939. This may be associated with historic disturbance patterns of fire, logging, and grazing that occurred on the upper slopes, allowing for alder establishment on these sites. Hardwood patch shapes became more complex over time, especially in riparian areas. Core area:edge area ratios increased. Hardwood patches were less heterogeneous in within-patch composition than expected, with large conifers the main non-hardwood cover type within patches; within-patch heterogeneity declined during the study period. Recent management practices are likely increasing hardwood fragmentation and shape complexity, and restricting the landscape distribution of hardwood patches. Title: Spatial pattern and dynamics of hardwood patches in the Coast Range of Oregon, 1939-1993 Author: Hess, Rebecca Susan Analysis of the long-term spatial pattern and dynamics of hardwood patches in the Coast Range of Oregon provides numerous ecological insights. Natural and anthropogenic disturbances have contributed to the development of a patchy mosaic of vegetation types in the area. Some hardwood patches in the Coast Range may be the precursors to stable vegetation states. The five objectives for the study were to: 1) develop the methodology for studying patch dynamics at landscape scales; 2) describe changes in the areal extent and occurrence of hardwood patches; 3) characterize the sizes and shapes, and size and shape changes of hardwood patches in the west-central Coast Range of Oregon; 4) describe the shift in within-patch heterogeneity and within-patch vegetation composition features of hardwood patches; and 5) characterize patches occurring in riparian areas. A viable methodology was developed for the detailed study of the change in vegetation patches across landscapes using scanned, georeferenced aerial photos, aerial photo interpretation of hardwood patches, and GIS techniques. Patch locations and characteristics were compared to a suite of environmental and other variables. The hardwood patch mosaic was not a stable landscape feature. The total area covered by hardwood patches, the weighted mean size of hardwood patches, and the number of patches sampled declined from 1939 to 1993. Forest Service lands showed the most dramatic drop in hardwood area, while private non-industrial lands showed the most dramatic increase in hardwood area. Most patches present in 1939 either disappeared or decreased in size. In 1993, hardwood patches were found closer to streams and on lower slope positions than in 1939. This may be associated with historic disturbance patterns of fire, logging, and grazing that occurred on the upper slopes, allowing for alder establishment on these sites. Hardwood patch shapes became more complex over time, especially in riparian areas. Core area:edge area ratios increased. Hardwood patches were less heterogeneous in within-patch composition than expected, with large conifers the main non-hardwood cover type within patches; within-patch heterogeneity declined during the study period. Recent management practices are likely increasing hardwood fragmentation and shape complexity, and restricting the landscape distribution of hardwood patches. Close

• 118. [Article] The bionomics of Medetera aldrichii Wheeler (Diptera: Dolichopodidae) in western Oregon

  The bionomics of Medetera aldrichii Wheeler (Diptera: Dolichopodidae), a predator of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins (Coleoptera:Scolytidae)), was investigated in western Oregon. The ...

  Citation × Citation Citation Abstract Copy Title: The bionomics of Medetera aldrichii Wheeler (Diptera: Dolichopodidae) in western Oregon Author: Fitzgerald, T. D. (Terrence D.), 1941- The bionomics of Medetera aldrichii Wheeler (Diptera: Dolichopodidae), a predator of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins (Coleoptera:Scolytidae)), was investigated in western Oregon. The predator pupated in host galleries proximal to bark beetle ventilation holes. The tendency of prepupal larvae to form pupal cells near illuminated areas in a photo-response apparatus suggested that light entering the bark of infested trees through ventilation holes may enable the larvae to locate potential exit sites. Larvae maintained under a 16:8 LD, 200 FC regime for 11 to 14 days pupated with significantly higher frequency than larvae maintained in darkness, indicating that light may also stimulate pupation. The photo-positive response of the pupa in a laboratory apparatus simulating the bark habitat suggested that it also orients to light when moving from the pupation site to the bark surface. Red pigmented mites and Collembola inhabiting the bark of host-infested trees are common components of the diet of the predaceous adults. Flies fed Onchiurus sp. (Collembola: Poduridae) consumed approximately 40 per day over a 13-15 day period. Mating, observed in the laboratory, is by superposition and lasts 20 to 30 minutes. Both sexes mate more than once and may copulate several times in a single day. Females maintained in the laboratory in small cages containing host-infested bark oviposited up to 630 eggs. The potential egg production of an individual, based on the maximum observed rate of oocyte turnover, and a longevity of 36 days, approximates 750 eggs. Field collected gravid females, isolated, from host-infested bark for five hours, deposited eggs in the pleats of paper cups during brief exposures to small quantities of volatilized commercial alphapinene. The response to the pinene, a common fraction of the oleoresins of various tree species which habor bark-beetle hosts of the fly, suggests that olfactory stimuli, released as the beetles mine the phloem, may guide in the selection of predator oviposition sites. The newly eclosed larva, provided with well developed pseudopodia, moves over the bark surface and enters the host gallery through a beetle entrance hole. Olfactometric studies indicated that the larva is strongly attracted to such holes, apparently orienting klinotactically to volatile materials, including alpha and beta-pinene, escaping from them. The attack and feeding behavior was observed in Lucite-bark sandwiches infested with developing broods of the Douglas-fir beetle. The larvae cannot penetrate un-mined phloem and gallery penetration is restricted until drying creates a bark-wood interspace. Predators feeding at the terminus of extended mines are usually isolated from other prey and completely consume each host before initiating new attacks. At high prey densities, however, the hosts galleries may be contiguous, enabling the predator to attack several prey in quick succession. Larvae maintained individually in plastic arenas in the laboratory consumed an average of 15 Douglas-fir beetle larvae during their development. Since the number of prey consumed decreased with the size of the prey, predators feeding on the largest prey instar acceptable, during each of the three stadia, required an average of 6.2 prey to achieve maturity. The impact of the predator on field populations of the Douglas-fir beetle was estimated by comparing bark beetle mortality in control and predator infested samples of five trees. At a mean predator density of 5.7 third-instar larvae per square-foot, mortality in the infested samples was 81.8 percent; significantly different from the 62.5 percent mortality occurring in the controls. Each predator larvae recovered at the end of the study killed an average of 3.7 hosts that would have been expected to survive in the absence of predation. Title: The bionomics of Medetera aldrichii Wheeler (Diptera: Dolichopodidae) in western Oregon Author: Fitzgerald, T. D. (Terrence D.), 1941- The bionomics of Medetera aldrichii Wheeler (Diptera: Dolichopodidae), a predator of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins (Coleoptera:Scolytidae)), was investigated in western Oregon. The predator pupated in host galleries proximal to bark beetle ventilation holes. The tendency of prepupal larvae to form pupal cells near illuminated areas in a photo-response apparatus suggested that light entering the bark of infested trees through ventilation holes may enable the larvae to locate potential exit sites. Larvae maintained under a 16:8 LD, 200 FC regime for 11 to 14 days pupated with significantly higher frequency than larvae maintained in darkness, indicating that light may also stimulate pupation. The photo-positive response of the pupa in a laboratory apparatus simulating the bark habitat suggested that it also orients to light when moving from the pupation site to the bark surface. Red pigmented mites and Collembola inhabiting the bark of host-infested trees are common components of the diet of the predaceous adults. Flies fed Onchiurus sp. (Collembola: Poduridae) consumed approximately 40 per day over a 13-15 day period. Mating, observed in the laboratory, is by superposition and lasts 20 to 30 minutes. Both sexes mate more than once and may copulate several times in a single day. Females maintained in the laboratory in small cages containing host-infested bark oviposited up to 630 eggs. The potential egg production of an individual, based on the maximum observed rate of oocyte turnover, and a longevity of 36 days, approximates 750 eggs. Field collected gravid females, isolated, from host-infested bark for five hours, deposited eggs in the pleats of paper cups during brief exposures to small quantities of volatilized commercial alphapinene. The response to the pinene, a common fraction of the oleoresins of various tree species which habor bark-beetle hosts of the fly, suggests that olfactory stimuli, released as the beetles mine the phloem, may guide in the selection of predator oviposition sites. The newly eclosed larva, provided with well developed pseudopodia, moves over the bark surface and enters the host gallery through a beetle entrance hole. Olfactometric studies indicated that the larva is strongly attracted to such holes, apparently orienting klinotactically to volatile materials, including alpha and beta-pinene, escaping from them. The attack and feeding behavior was observed in Lucite-bark sandwiches infested with developing broods of the Douglas-fir beetle. The larvae cannot penetrate un-mined phloem and gallery penetration is restricted until drying creates a bark-wood interspace. Predators feeding at the terminus of extended mines are usually isolated from other prey and completely consume each host before initiating new attacks. At high prey densities, however, the hosts galleries may be contiguous, enabling the predator to attack several prey in quick succession. Larvae maintained individually in plastic arenas in the laboratory consumed an average of 15 Douglas-fir beetle larvae during their development. Since the number of prey consumed decreased with the size of the prey, predators feeding on the largest prey instar acceptable, during each of the three stadia, required an average of 6.2 prey to achieve maturity. The impact of the predator on field populations of the Douglas-fir beetle was estimated by comparing bark beetle mortality in control and predator infested samples of five trees. At a mean predator density of 5.7 third-instar larvae per square-foot, mortality in the infested samples was 81.8 percent; significantly different from the 62.5 percent mortality occurring in the controls. Each predator larvae recovered at the end of the study killed an average of 3.7 hosts that would have been expected to survive in the absence of predation. Close

• 119. [Article] Variation in metabolism, thallus characteristics, and water relations of three populations of Loboria pulmonaria from western Oregon

  A physio-ecological study of Lobaria pulmonaria (L. ) Hoffm. was done to determine if geographic variation occurred within the species. Lobaria pulmonaria was collected from Table Mountain, Oak Creek, ...

  Citation × Citation Citation Abstract Copy Title: Variation in metabolism, thallus characteristics, and water relations of three populations of Loboria pulmonaria from western Oregon Author: Neil, Garry Allen A physio-ecological study of Lobaria pulmonaria (L. ) Hoffm. was done to determine if geographic variation occurred within the species. Lobaria pulmonaria was collected from Table Mountain, Oak Creek, and Lost Prairie, located in the Coast Range, Willamette Valley, and Cascade Range respectively in Western Oregon. During 1971 and 1972 experiments were conducted to determine physical and chemical characteristics, thallus water content-water potential relations, and metabolic oxygen exchange rates in relation to light intensity, temperature, relative water content (RWC), and water potential. No differences were observed in the morphology, thallus area-density, presence of stictic and norstictic acids, chlorophyll concentrations, or metabolic response to temperature among the three populations of L. pulmonaria. However, results of other experiments indicated the possibility that L. pulmonaria has evolved intraspecific differences between the Oak Creek population and the montane groups. The Oak Creek population, situated in the most xeric habitat, showed a slow decrease in water potential as the plant lost water ( -0. 9 bars /%RWC); a relatively high light compensation point (>50 ft-c); a high light saturation point (1000 ft-c); a high tolerance to high light intensities before photo-inhibition occurred (±1900 ft-c); a low range of relative water content at maximum photosynthesis (53-75%); and an ability to maintain maximum net photosynthesis until water potential reached -12.5 bars. In contrast, the Table Mountain and Lost Prairie populations showed a rapid decrease in water potential as the plant lost water (-2.4 and -2.6 bars /%RWC respectively); a low light compensation point (<50 ft-c); a low light saturation point (440 and 300 ft-c respectively); a low tolerance to high light intensities indicated by photo-inhibition above 775 ft-c; and an inability to stay at maximum net photosynthesis once water potential dropped below -2.0 and -0.5 bars respectively. The Lost Prairie population was similar in its range of relative water content at maximum photosynthesis to that of the Oak Creek group (52-76%); however, the Table Mountain population had a higher range at 72 to 82%. Title: Variation in metabolism, thallus characteristics, and water relations of three populations of Loboria pulmonaria from western Oregon Author: Neil, Garry Allen A physio-ecological study of Lobaria pulmonaria (L. ) Hoffm. was done to determine if geographic variation occurred within the species. Lobaria pulmonaria was collected from Table Mountain, Oak Creek, and Lost Prairie, located in the Coast Range, Willamette Valley, and Cascade Range respectively in Western Oregon. During 1971 and 1972 experiments were conducted to determine physical and chemical characteristics, thallus water content-water potential relations, and metabolic oxygen exchange rates in relation to light intensity, temperature, relative water content (RWC), and water potential. No differences were observed in the morphology, thallus area-density, presence of stictic and norstictic acids, chlorophyll concentrations, or metabolic response to temperature among the three populations of L. pulmonaria. However, results of other experiments indicated the possibility that L. pulmonaria has evolved intraspecific differences between the Oak Creek population and the montane groups. The Oak Creek population, situated in the most xeric habitat, showed a slow decrease in water potential as the plant lost water ( -0. 9 bars /%RWC); a relatively high light compensation point (>50 ft-c); a high light saturation point (1000 ft-c); a high tolerance to high light intensities before photo-inhibition occurred (±1900 ft-c); a low range of relative water content at maximum photosynthesis (53-75%); and an ability to maintain maximum net photosynthesis until water potential reached -12.5 bars. In contrast, the Table Mountain and Lost Prairie populations showed a rapid decrease in water potential as the plant lost water (-2.4 and -2.6 bars /%RWC respectively); a low light compensation point (<50 ft-c); a low light saturation point (440 and 300 ft-c respectively); a low tolerance to high light intensities indicated by photo-inhibition above 775 ft-c; and an inability to stay at maximum net photosynthesis once water potential dropped below -2.0 and -0.5 bars respectively. The Lost Prairie population was similar in its range of relative water content at maximum photosynthesis to that of the Oak Creek group (52-76%); however, the Table Mountain population had a higher range at 72 to 82%. Close

• 120. [Article] Nonlinear Terahertz Spectroscopy and imaging of Carbon Nanomaterials

  This dissertation presents nonlinear terahertz (THz) properties of carbon nanomaterials investigated by time-resolved high-field THz spectroscopy. In order to determine THz characteristics of nanomaterials, ...

  Citation × Citation Citation Abstract Copy Title: Nonlinear Terahertz Spectroscopy and imaging of Carbon Nanomaterials Author: Lee, Byounghwak This dissertation presents nonlinear terahertz (THz) properties of carbon nanomaterials investigated by time-resolved high-field THz spectroscopy. In order to determine THz characteristics of nanomaterials, we performed THz power spectrum measurement, THz raster imaging, THz time-domain spectroscopy (THz-TDS) and time-resolved pump-probe experiment on two different types of single layer graphene and a free standing multi-walled carbon nanotubes (MWCNTs), utilizing strong single-cycle THz pulses (central frequency, 0.9 THz; bandwidth, 1 THz; THz field amplitude, E_THz>1 MV/cm) generated by optical rectification (a second order nonlinear optical process) of femtosecond laser pulses (pulse energy, 1 mJ; pulse duration, 100 fs; repetition rate, 1 kHz) with titled pulse front for phase matching between optical and THz pulses in LiNbO₃ crystal. Strong and broadband THz pulses induce transparency single layer graphene grown by catalytic chemical vapor deposition (CVD). A substrate-free homogeneous graphene becomes more transparent to the THz radiation than an inhomogeneous graphene on silicon as the peak strength of THz field increases over 50kV/cm considered as the threshold of the nonlinear transparency effect. The experimental results show that suspended graphene is more efficient to manipulate THz signal than one with a substrate. Free-standing MWCNTs drawn from a forest of MWCNTs synthesized by CVD exhibit highly anisotropic linear and nonlinear THz responses. There are no nonlinear effects for the polarization perpendicular to the MWCNT axis, whereas, in the parallel polarization configuration, intense THz pulses induce nonlinear absorption in the quasi-one-dimensional conducting media. That is, it is revealed via time-resolved measurements of transmitted THz pulses and a theoretical analysis of the data that strong THz fields enhance permittivity in carbon nanotubes by generating charge carriers. Optical-Pump/THz-probe (OPTP) spectroscopy shows that optical pump pulses induce interband transitions in MWCNTs: Its conductivity is increased by generating photo-excited hot-carriers as the optical pump energy increases. On the other hand, Optical-Pump/Intense THz-Pump spectroscopy (OPITP) exhibits three carrier dynamics phenomena which are optical pump-induced absorption, THz field-induced absorption and transparency in MWCNTs: Intense THz and optical pump energies (E_THz<538kV/cm and I_opt=103μJ/cm²) give rise to photo-excited hot-carriers and THz field induced-carrier density via band to band transitions, however, sub-band scattering dominant in the THz-field range between 538 to 653kV/cm leads to increased effective mass, which reduces carrier mobility. Title: Nonlinear Terahertz Spectroscopy and imaging of Carbon Nanomaterials Author: Lee, Byounghwak This dissertation presents nonlinear terahertz (THz) properties of carbon nanomaterials investigated by time-resolved high-field THz spectroscopy. In order to determine THz characteristics of nanomaterials, we performed THz power spectrum measurement, THz raster imaging, THz time-domain spectroscopy (THz-TDS) and time-resolved pump-probe experiment on two different types of single layer graphene and a free standing multi-walled carbon nanotubes (MWCNTs), utilizing strong single-cycle THz pulses (central frequency, 0.9 THz; bandwidth, 1 THz; THz field amplitude, E_THz>1 MV/cm) generated by optical rectification (a second order nonlinear optical process) of femtosecond laser pulses (pulse energy, 1 mJ; pulse duration, 100 fs; repetition rate, 1 kHz) with titled pulse front for phase matching between optical and THz pulses in LiNbO₃ crystal. Strong and broadband THz pulses induce transparency single layer graphene grown by catalytic chemical vapor deposition (CVD). A substrate-free homogeneous graphene becomes more transparent to the THz radiation than an inhomogeneous graphene on silicon as the peak strength of THz field increases over 50kV/cm considered as the threshold of the nonlinear transparency effect. The experimental results show that suspended graphene is more efficient to manipulate THz signal than one with a substrate. Free-standing MWCNTs drawn from a forest of MWCNTs synthesized by CVD exhibit highly anisotropic linear and nonlinear THz responses. There are no nonlinear effects for the polarization perpendicular to the MWCNT axis, whereas, in the parallel polarization configuration, intense THz pulses induce nonlinear absorption in the quasi-one-dimensional conducting media. That is, it is revealed via time-resolved measurements of transmitted THz pulses and a theoretical analysis of the data that strong THz fields enhance permittivity in carbon nanotubes by generating charge carriers. Optical-Pump/THz-probe (OPTP) spectroscopy shows that optical pump pulses induce interband transitions in MWCNTs: Its conductivity is increased by generating photo-excited hot-carriers as the optical pump energy increases. On the other hand, Optical-Pump/Intense THz-Pump spectroscopy (OPITP) exhibits three carrier dynamics phenomena which are optical pump-induced absorption, THz field-induced absorption and transparency in MWCNTs: Intense THz and optical pump energies (E_THz<538kV/cm and I_opt=103μJ/cm²) give rise to photo-excited hot-carriers and THz field induced-carrier density via band to band transitions, however, sub-band scattering dominant in the THz-field range between 538 to 653kV/cm leads to increased effective mass, which reduces carrier mobility. Close