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• 28631. [Article] Healthy Eating and Active Living - Mapping Attributes Using Participatory Photographic Surveys: Building Leadership Capacity in the Latino Population

  Healthy Eating, Active Living - Mapping Attributes using Participatory Photographic Surveys (HEAL MAPPS) was used to engage Albany’s Latino community to explore the environmental conditions that support ...

  Citation × Citation Citation Abstract Copy Title: Healthy Eating and Active Living - Mapping Attributes Using Participatory Photographic Surveys: Building Leadership Capacity in the Latino Population Author: Nunez, Yanet, Vera, Tina D. Healthy Eating, Active Living - Mapping Attributes using Participatory Photographic Surveys (HEAL MAPPS) was used to engage Albany’s Latino community to explore the environmental conditions that support or hinder healthful eating and physical activity behaviors among youth and families. HEAL MAPPS is a community-based participatory research tool developed by OSU obesity prevention researchers. Latinos were mobilized to assess Albany’s HEAL-related issues, prioritize concerns, and further develop advocacy skills and action groups. This project engaged emerging Latino leaders and residents with the wider community and increased capacity for improving the local HEAL environment and health inequities that exist in Albany. The specific aims of research: (a) provide culturally and linguistically appropriate leadership training (b) increase leadership skills and confidence in civic engagement (c) increase participants’ civic engagement, i.e. Make policy and program recommendations; develop a policy action plan; and disseminate project findings to the community and local policy makers. Albany residents “Familias Activas” generated 18 maps representing routes traveled on foot or by motor vehicle to interact with the Albany food and physical activity environment. They photographed over 222 features of the community related to healthy eating and physical activity for children, youth, and adults in Albany. Twelve participated in a focus group meeting to organize the community’s HEAL MAPPS™ photo journal for the community conversation. At the end of HEAL MAPPS project timeline, a community report will be completed and will be available in Spanish and English. Familias Activas leadership group will develop an advocacy campaign around one identified priority. Title: Healthy Eating and Active Living - Mapping Attributes Using Participatory Photographic Surveys: Building Leadership Capacity in the Latino Population Author: Nunez, Yanet, Vera, Tina D. Healthy Eating, Active Living - Mapping Attributes using Participatory Photographic Surveys (HEAL MAPPS) was used to engage Albany’s Latino community to explore the environmental conditions that support or hinder healthful eating and physical activity behaviors among youth and families. HEAL MAPPS is a community-based participatory research tool developed by OSU obesity prevention researchers. Latinos were mobilized to assess Albany’s HEAL-related issues, prioritize concerns, and further develop advocacy skills and action groups. This project engaged emerging Latino leaders and residents with the wider community and increased capacity for improving the local HEAL environment and health inequities that exist in Albany. The specific aims of research: (a) provide culturally and linguistically appropriate leadership training (b) increase leadership skills and confidence in civic engagement (c) increase participants’ civic engagement, i.e. Make policy and program recommendations; develop a policy action plan; and disseminate project findings to the community and local policy makers. Albany residents “Familias Activas” generated 18 maps representing routes traveled on foot or by motor vehicle to interact with the Albany food and physical activity environment. They photographed over 222 features of the community related to healthy eating and physical activity for children, youth, and adults in Albany. Twelve participated in a focus group meeting to organize the community’s HEAL MAPPS™ photo journal for the community conversation. At the end of HEAL MAPPS project timeline, a community report will be completed and will be available in Spanish and English. Familias Activas leadership group will develop an advocacy campaign around one identified priority. Close

• 28632. [Article] Long-term Colonization Of A Subarctic Artificial Reef System In Whittier, Alaska

  Presented at the American Academy of Underwater Science annual conference in Providence, RI

  Citation × Citation Citation Abstract Copy Title: Long-term Colonization Of A Subarctic Artificial Reef System In Whittier, Alaska Author: Levy, Charlotte Presented at the American Academy of Underwater Science annual conference in Providence, RI Title: Long-term Colonization Of A Subarctic Artificial Reef System In Whittier, Alaska Author: Levy, Charlotte Presented at the American Academy of Underwater Science annual conference in Providence, RI Close

• 28633. [Article] Improving Target Amino Acid Selectivity in a Permissive Aminoacyl tRNA Synthetase Through Counter-Selection

  The amino acid acridon-2-ylalanine (Acd) can be a valuable probe of protein dynamics, either alone or as part of a Förster resonance energy transfer (FRET) or photo-induced electron transfer (eT) probe ...

  Citation × Citation Citation Abstract Copy Title: Improving Target Amino Acid Selectivity in a Permissive Aminoacyl tRNA Synthetase Through Counter-Selection Author: Sungwienwong, Itthipol, Hostetler, Zachary M., Blizzard, Robert J., Porter, Joseph J., Driggers, Camden D., Mbengi, Lea Z., Villegas, José A., Speight, Lee C., Saven, Jeffery G., Perona, John J., Kohli, Rahul M., Mehl, Ryan A., Petersson, E. James Year: 2017 The amino acid acridon-2-ylalanine (Acd) can be a valuable probe of protein dynamics, either alone or as part of a Förster resonance energy transfer (FRET) or photo-induced electron transfer (eT) probe pair. We have previously reported the genetic incorporation of Acd by an aminoacyl tRNA synthetase (RS). However, this RS, developed from a library of permissive RSs, also incorporates N-phenyl-aminophenylalanine (Npf), a trace byproduct of one Acd synthetic route. We have performed negative selections in the presence of Npf and analyzed the selectivity of the resulting AcdRSs by in vivo protein expression and detailed kinetic analyses of the purified RSs. We find that selection conferred a ∼50-fold increase in selectivity for Acd over Npf, eliminating incorporation of Npf contaminants, and allowing one to use a high yielding Acd synthetic route for improved overall expression of Acd-containing proteins. More generally, our report also provides a cautionary tale on the use of permissive RSs, as well as a strategy for improving selectivity for the target amino acid. Title: Improving Target Amino Acid Selectivity in a Permissive Aminoacyl tRNA Synthetase Through Counter-Selection Author: Sungwienwong, Itthipol, Hostetler, Zachary M., Blizzard, Robert J., Porter, Joseph J., Driggers, Camden D., Mbengi, Lea Z., Villegas, José A., Speight, Lee C., Saven, Jeffery G., Perona, John J., Kohli, Rahul M., Mehl, Ryan A., Petersson, E. James Year: 2017 The amino acid acridon-2-ylalanine (Acd) can be a valuable probe of protein dynamics, either alone or as part of a Förster resonance energy transfer (FRET) or photo-induced electron transfer (eT) probe pair. We have previously reported the genetic incorporation of Acd by an aminoacyl tRNA synthetase (RS). However, this RS, developed from a library of permissive RSs, also incorporates N-phenyl-aminophenylalanine (Npf), a trace byproduct of one Acd synthetic route. We have performed negative selections in the presence of Npf and analyzed the selectivity of the resulting AcdRSs by in vivo protein expression and detailed kinetic analyses of the purified RSs. We find that selection conferred a ∼50-fold increase in selectivity for Acd over Npf, eliminating incorporation of Npf contaminants, and allowing one to use a high yielding Acd synthetic route for improved overall expression of Acd-containing proteins. More generally, our report also provides a cautionary tale on the use of permissive RSs, as well as a strategy for improving selectivity for the target amino acid. Close

• 28634. [Article] An examination of the form and variability of manganese oxide in Columbia River suspended material

  Suspended particulate matter (SPM) in the Columbia River is a mixture of particles of several origins having varying physical and biogeochemical properties. The relative abundances of these freshwater ...

  Citation × Citation Citation Abstract Copy Title: An examination of the form and variability of manganese oxide in Columbia River suspended material Author: Covert, Paul Allister Suspended particulate matter (SPM) in the Columbia River is a mixture of particles of several origins having varying physical and biogeochemical properties. The relative abundances of these freshwater particles changes with season and apparently also with tide. Prior investigation has quantified seasonal variation of organic material in both the Columbia and Willamette rivers. In this investigation, seasonal variability in the abundace of manganese in the mineral fraction (Mn/Al) is confirmed in both rivers. Mn/Al hovers around 0.01 (crustal average = 0.011, Whetten et al., 1969) during the winter and early spring, rising in the spring and summer to 0.04 and 0.06 in the Columbia and Willamette Rivers, respectively. Results from particle settling experiments and electron microprobe photos of SPM indicate that seasonal Mn/Al variability is a result of addition of Mn-oxides to SPM in the summer months, and that these oxides exist as discrete, slow settling particles. A short-term (12 hour) variability of Mn/Al, as well as Chl a/POC, is observed at mid-depth in the Columbia River. Owen Tube particle settling experiments revealed that with respect to geochemical properties, SPM could be divided into two settling classes: slow (<0.11 cm/s) and fast (>0.11 cm/s). Particles in the slow settling class were typically enriched in Mn and Chl a , while fast settling particles were more characteristic of detrital material. One consequence of this geochemical separation is that it leads to differential particle settling and resuspension in the tidal freshwater portions of the river, resulting in the observed 12-hour variability of SPM character. Such variability could have further reaching consequences with regard to chemical transport and dispersal. Title: An examination of the form and variability of manganese oxide in Columbia River suspended material Author: Covert, Paul Allister Suspended particulate matter (SPM) in the Columbia River is a mixture of particles of several origins having varying physical and biogeochemical properties. The relative abundances of these freshwater particles changes with season and apparently also with tide. Prior investigation has quantified seasonal variation of organic material in both the Columbia and Willamette rivers. In this investigation, seasonal variability in the abundace of manganese in the mineral fraction (Mn/Al) is confirmed in both rivers. Mn/Al hovers around 0.01 (crustal average = 0.011, Whetten et al., 1969) during the winter and early spring, rising in the spring and summer to 0.04 and 0.06 in the Columbia and Willamette Rivers, respectively. Results from particle settling experiments and electron microprobe photos of SPM indicate that seasonal Mn/Al variability is a result of addition of Mn-oxides to SPM in the summer months, and that these oxides exist as discrete, slow settling particles. A short-term (12 hour) variability of Mn/Al, as well as Chl a/POC, is observed at mid-depth in the Columbia River. Owen Tube particle settling experiments revealed that with respect to geochemical properties, SPM could be divided into two settling classes: slow (<0.11 cm/s) and fast (>0.11 cm/s). Particles in the slow settling class were typically enriched in Mn and Chl a , while fast settling particles were more characteristic of detrital material. One consequence of this geochemical separation is that it leads to differential particle settling and resuspension in the tidal freshwater portions of the river, resulting in the observed 12-hour variability of SPM character. Such variability could have further reaching consequences with regard to chemical transport and dispersal. Close

• 28635. [Article] Photochemical degradation of sediment organic matter : effect on Zn-65 release

  Columbia River sediment was irradiated with ultraviolet light to determine if organic material could be removed without altering the sorptive properties of the hydrous oxides of iron and manganese. A laboratory ...

  Citation × Citation Citation Abstract Copy Title: Photochemical degradation of sediment organic matter : effect on Zn-65 release Author: Lenaers, William Michael Columbia River sediment was irradiated with ultraviolet light to determine if organic material could be removed without altering the sorptive properties of the hydrous oxides of iron and manganese. A laboratory preparation of Zn-65 spiked hydrous ferric oxide was subjected to ultraviolet irradiation in order to assess the photochemical effect upon Zn-65 release. The photochemically induced release of Mn-54 present on the Columbia River sediment was used to assess the effect on the hydrous oxides of manganese. The ultraviolet irradiation proved effective in removing up to 68% of the sedimentary organic material in 17 hours without causing release of Zn-65 or Sc-46. While the ultraviolet irradiation had no effect upon Zn-65 release from laboratory preparations of hydrous ferric oxides and Zn-65 spiked montmorillonite, a significant release of Mn-54 resulted from the photolysis treatment. The removal of Mn-54 was not accompanied by the release of sorbed Zn-65 or Sc-46 (nuclides expected to be sorbed by hydrous oxides), nor did there appear to be any permanent change in the nature of the Mn-54 on the sediment. Although it is possible that the hydrous oxides of manganese are affected by the ultraviolet treatment, it is likely that another species, such as the carbonate, is the species involved. Photo-oxidation appears to provide a method of obtaining sediments with substantially reduced organic content without affecting the sorptive properties of hydrous oxides or clay minerals. This result should allow the use of uptake studies to determine the importance of organic material in trace metal sorption by sediments. Title: Photochemical degradation of sediment organic matter : effect on Zn-65 release Author: Lenaers, William Michael Columbia River sediment was irradiated with ultraviolet light to determine if organic material could be removed without altering the sorptive properties of the hydrous oxides of iron and manganese. A laboratory preparation of Zn-65 spiked hydrous ferric oxide was subjected to ultraviolet irradiation in order to assess the photochemical effect upon Zn-65 release. The photochemically induced release of Mn-54 present on the Columbia River sediment was used to assess the effect on the hydrous oxides of manganese. The ultraviolet irradiation proved effective in removing up to 68% of the sedimentary organic material in 17 hours without causing release of Zn-65 or Sc-46. While the ultraviolet irradiation had no effect upon Zn-65 release from laboratory preparations of hydrous ferric oxides and Zn-65 spiked montmorillonite, a significant release of Mn-54 resulted from the photolysis treatment. The removal of Mn-54 was not accompanied by the release of sorbed Zn-65 or Sc-46 (nuclides expected to be sorbed by hydrous oxides), nor did there appear to be any permanent change in the nature of the Mn-54 on the sediment. Although it is possible that the hydrous oxides of manganese are affected by the ultraviolet treatment, it is likely that another species, such as the carbonate, is the species involved. Photo-oxidation appears to provide a method of obtaining sediments with substantially reduced organic content without affecting the sorptive properties of hydrous oxides or clay minerals. This result should allow the use of uptake studies to determine the importance of organic material in trace metal sorption by sediments. Close

• 28636. [Article] New luminescent materials and high-performance solution-processed oxide thin films

  Crystals of an incongruent-melting compound, Ba₃MgSi₂O₈, were grown by the flux method and its structure was determined by single crystal X-ray diffraction methods. Ba₃MgSi₂O₈ crystallizes in trigonal ...

  Citation × Citation Citation Abstract Copy Title: New luminescent materials and high-performance solution-processed oxide thin films Author: Jiang, Kai Crystals of an incongruent-melting compound, Ba₃MgSi₂O₈, were grown by the flux method and its structure was determined by single crystal X-ray diffraction methods. Ba₃MgSi₂O₈ crystallizes in trigonal space group P-3[bar]m1 with a = 5.6123(3) Å, c = 7.2667(9) Å and Z = 1. Eu²⁺ ions prefer one crystallographic Ba site in the structure and exhibit strong blue emissions at 440 nm. A new series of compounds RE₄Zn₄(SiO₄)₅ (RE=Y, La, Eu, Gd, Tb, Dy, Ho, Er), adopting an unprecedented new structure type, was discovered. Crystals of Y₄Zn₄(SiO₄)₅ were grown from a silica-rich eutectic melt and its structure was determined by single-crystal diffraction methods. It crystallizes in tetragonal space group P4₂/n with cell dimensions a = 9.3289(10) Å, c = 9.0509(18) Å and Z = 2. Selected photo-luminescence properties of lanthanide ions doped Y₄Zn₄(SiO₄)₅ are presented. High-purity MgS:Eu phosphors, exhibiting distinct cubic morphology, high luminescence efficacy, and stability against moisture, were synthesized. Thin films of early transition metal oxides (TiO₂, HfO₂, Nb₂O₅, and V₂O₅) have been deposited from peroxo-assisted aqueous solutions. The facile decomposition of peroxo ligands upon annealing allows smooth and efficient transformation of the precursors into high-quality films. Therefore, the films exhibit extraordinary performance in advanced optical and electrical devices, such as dielectric mirrors, microcavities, capacitors, and thin-film transistors (TFTs). The control over film thickness to a single-digit nm thickness is also demonstrated through the fabrication of TiO₂−AlPO nanolaminates using simple beaker chemistry. Title: New luminescent materials and high-performance solution-processed oxide thin films Author: Jiang, Kai Crystals of an incongruent-melting compound, Ba₃MgSi₂O₈, were grown by the flux method and its structure was determined by single crystal X-ray diffraction methods. Ba₃MgSi₂O₈ crystallizes in trigonal space group P-3[bar]m1 with a = 5.6123(3) Å, c = 7.2667(9) Å and Z = 1. Eu²⁺ ions prefer one crystallographic Ba site in the structure and exhibit strong blue emissions at 440 nm. A new series of compounds RE₄Zn₄(SiO₄)₅ (RE=Y, La, Eu, Gd, Tb, Dy, Ho, Er), adopting an unprecedented new structure type, was discovered. Crystals of Y₄Zn₄(SiO₄)₅ were grown from a silica-rich eutectic melt and its structure was determined by single-crystal diffraction methods. It crystallizes in tetragonal space group P4₂/n with cell dimensions a = 9.3289(10) Å, c = 9.0509(18) Å and Z = 2. Selected photo-luminescence properties of lanthanide ions doped Y₄Zn₄(SiO₄)₅ are presented. High-purity MgS:Eu phosphors, exhibiting distinct cubic morphology, high luminescence efficacy, and stability against moisture, were synthesized. Thin films of early transition metal oxides (TiO₂, HfO₂, Nb₂O₅, and V₂O₅) have been deposited from peroxo-assisted aqueous solutions. The facile decomposition of peroxo ligands upon annealing allows smooth and efficient transformation of the precursors into high-quality films. Therefore, the films exhibit extraordinary performance in advanced optical and electrical devices, such as dielectric mirrors, microcavities, capacitors, and thin-film transistors (TFTs). The control over film thickness to a single-digit nm thickness is also demonstrated through the fabrication of TiO₂−AlPO nanolaminates using simple beaker chemistry. Close

• 28637. [Article] Ecosystem Analysis of Wetland and Riparian Zone restoration at the Hart Mountain Antelope Refuge over Twenty Years

  Presentation entitled : Ecosystem Analysis of Wetland and Riparian Zone restoration at the Hart Mountain Antelope Refuge over Twenty Years / by Schyler Reis, Lisa Ellsworth and J. Boone Kauffman

  Citation × Citation Citation Abstract Copy Title: Ecosystem Analysis of Wetland and Riparian Zone restoration at the Hart Mountain Antelope Refuge over Twenty Years Author: Reis, Schyler Ainsworth Presentation entitled : Ecosystem Analysis of Wetland and Riparian Zone restoration at the Hart Mountain Antelope Refuge over Twenty Years / by Schyler Reis, Lisa Ellsworth and J. Boone Kauffman Title: Ecosystem Analysis of Wetland and Riparian Zone restoration at the Hart Mountain Antelope Refuge over Twenty Years Author: Reis, Schyler Ainsworth Presentation entitled : Ecosystem Analysis of Wetland and Riparian Zone restoration at the Hart Mountain Antelope Refuge over Twenty Years / by Schyler Reis, Lisa Ellsworth and J. Boone Kauffman Close

• 28638. [Article] Riparian canopy and channel response to hillslope disturbance in Elk River Basin, southwest Oregon

  Elk River is a sixth order stream, draining a 200 square kilometer basin in the Klainath Mountain province of southwestern Oregon. Timber harvesting began in the basin during the 1950's, with peak removal ...

  Citation × Citation Citation Abstract Copy Title: Riparian canopy and channel response to hillslope disturbance in Elk River Basin, southwest Oregon Author: Ryan-Burkett, Sandra E. Elk River is a sixth order stream, draining a 200 square kilometer basin in the Klainath Mountain province of southwestern Oregon. Timber harvesting began in the basin during the 1950's, with peak removal of wood occurring in the mid to late 1960's. This activity lead to an increase in the frequency of landsliding and surface erosion. The downstream effects of this increase in sediment were evaluated by interpreting aerial photography spanning the period 1956 to 1979. Opening or enlargement of the riparian canopy cover was used as an indicator of sediment impacts. Results indicate that in most basins, changes in downstream channel conditions could not be directly linked to the increase in sediment delivered from harvested areas. Opening on higher order channels occurred throughout the study period, but did not exhibit patterns indicative of a large pulse of sediment moving through the system. Rather, opening in fourth to fifth order channels was attributed to the interaction between local sediment sources and channel morphology, with unconstrained, flat channel segments exhibiting chronic opening. The distribution of constrained and unconstrained channel reaches was defined by a Channel Morphology Index (CMI), which compared relative width and gradient changes to channel averages. A 100-year event in 1964 did not produce effects in Elk River Basin on the same order of magnitude as other basins in the Pacific Northwest. Downstream effects were important in a few areas where landslides and high rates of surface erosion were directly linked to opening and channel widening downstream. Limited channel response to hillslope. disturbance in Elk River Basin over the period 1956-79 was attributed to four factors: lack of debris flows in most areas of the basin, channels constrained by competent hillslopes and bedrock limiting the extent of opening, channel conditions inherited from storms prior to 1956, and essentially pristine conditions over much of the basin at the time of the 1964 storm. Finally, sequential air photo interpretation proved useful in deciphering disturbance history and analyzing processes which create downstream effects. Title: Riparian canopy and channel response to hillslope disturbance in Elk River Basin, southwest Oregon Author: Ryan-Burkett, Sandra E. Elk River is a sixth order stream, draining a 200 square kilometer basin in the Klainath Mountain province of southwestern Oregon. Timber harvesting began in the basin during the 1950's, with peak removal of wood occurring in the mid to late 1960's. This activity lead to an increase in the frequency of landsliding and surface erosion. The downstream effects of this increase in sediment were evaluated by interpreting aerial photography spanning the period 1956 to 1979. Opening or enlargement of the riparian canopy cover was used as an indicator of sediment impacts. Results indicate that in most basins, changes in downstream channel conditions could not be directly linked to the increase in sediment delivered from harvested areas. Opening on higher order channels occurred throughout the study period, but did not exhibit patterns indicative of a large pulse of sediment moving through the system. Rather, opening in fourth to fifth order channels was attributed to the interaction between local sediment sources and channel morphology, with unconstrained, flat channel segments exhibiting chronic opening. The distribution of constrained and unconstrained channel reaches was defined by a Channel Morphology Index (CMI), which compared relative width and gradient changes to channel averages. A 100-year event in 1964 did not produce effects in Elk River Basin on the same order of magnitude as other basins in the Pacific Northwest. Downstream effects were important in a few areas where landslides and high rates of surface erosion were directly linked to opening and channel widening downstream. Limited channel response to hillslope. disturbance in Elk River Basin over the period 1956-79 was attributed to four factors: lack of debris flows in most areas of the basin, channels constrained by competent hillslopes and bedrock limiting the extent of opening, channel conditions inherited from storms prior to 1956, and essentially pristine conditions over much of the basin at the time of the 1964 storm. Finally, sequential air photo interpretation proved useful in deciphering disturbance history and analyzing processes which create downstream effects. Close

• 28639. [Article] Contribution of deep-seated bedrock landslides to denudation of a glaciated basin in southern Alaska

  The role of bedrock landslides in the denudation of fluvial catchments has received considerable attention, whereas the relative contribution of deep-seated bedrock landslides to the erosion of glaciated ...

  Citation × Citation Citation Abstract Copy Title: Contribution of deep-seated bedrock landslides to denudation of a glaciated basin in southern Alaska Author: Arsenault, Ann Michelle The role of bedrock landslides in the denudation of fluvial catchments has received considerable attention, whereas the relative contribution of deep-seated bedrock landslides to the erosion of glaciated basins is less well known. A glaciated basin in the Chugach-St. Elias Range of southern Alaska was chosen to investigate the contribution of bedrock landslides because the debris from four major landslides on the surface of a glacier is easily distinguished from moraines and other supraglacial material. The sediment in the landslides was derived entirely from the hillslopes, as evidenced by large scars visible on the basin walls. A series of aerial and satellite photos from 1978 to 2000 and field observations in 2001 and 2002 indicate that three of the four landslides have fallen onto the surface of the glacier since -1978. The landslides originated from the steeply dipping (60-70°) bedrock walls and were deposited onto the glacier in the ablation zone. Landslide material is currently being transported downstream supraglacially. Valley walls are composed of high-grade metamorphic rock, have a steep north-dipping foliation, are fractured by numerous large joints, and have an average relief of -400 meters. A total landslide volume of - 2.3 x 105 m3 was determined by combining surface profiles, area, and thickness from high-resolution survey data. This volume indicates that deep-seated landslides resulted in a basin-scale erosion rate of 0.4 mm yr 1.Other investigations that have attempted to quantify the sediment contribution from supraglacial sources, report that sediment derived from the basin walls could represent 24-60% of the overall erosion. If correct, the total landslide volume can be used to infer an overall, basin-scale erosion rate of 0.7 to 1.7 mm yrt. Title: Contribution of deep-seated bedrock landslides to denudation of a glaciated basin in southern Alaska Author: Arsenault, Ann Michelle The role of bedrock landslides in the denudation of fluvial catchments has received considerable attention, whereas the relative contribution of deep-seated bedrock landslides to the erosion of glaciated basins is less well known. A glaciated basin in the Chugach-St. Elias Range of southern Alaska was chosen to investigate the contribution of bedrock landslides because the debris from four major landslides on the surface of a glacier is easily distinguished from moraines and other supraglacial material. The sediment in the landslides was derived entirely from the hillslopes, as evidenced by large scars visible on the basin walls. A series of aerial and satellite photos from 1978 to 2000 and field observations in 2001 and 2002 indicate that three of the four landslides have fallen onto the surface of the glacier since -1978. The landslides originated from the steeply dipping (60-70°) bedrock walls and were deposited onto the glacier in the ablation zone. Landslide material is currently being transported downstream supraglacially. Valley walls are composed of high-grade metamorphic rock, have a steep north-dipping foliation, are fractured by numerous large joints, and have an average relief of -400 meters. A total landslide volume of - 2.3 x 105 m3 was determined by combining surface profiles, area, and thickness from high-resolution survey data. This volume indicates that deep-seated landslides resulted in a basin-scale erosion rate of 0.4 mm yr 1.Other investigations that have attempted to quantify the sediment contribution from supraglacial sources, report that sediment derived from the basin walls could represent 24-60% of the overall erosion. If correct, the total landslide volume can be used to infer an overall, basin-scale erosion rate of 0.7 to 1.7 mm yrt. Close

• 28640. [Article] Tandem intramolecular photocycloaddition-retro-Mannich fragmentation as a route to indole and oxindole

  Irradiation of a tryptamine linked through its side-chain nitrogen to an alkylidene malonate residue results in an intramolecular [2 + 2] cycloaddition to the indole 2,3-double bond. The resultant cyclobutane ...

  Citation × Citation Citation Abstract Copy Title: Tandem intramolecular photocycloaddition-retro-Mannich fragmentation as a route to indole and oxindole Author: Li, Yang Irradiation of a tryptamine linked through its side-chain nitrogen to an alkylidene malonate residue results in an intramolecular [2 + 2] cycloaddition to the indole 2,3-double bond. The resultant cyclobutane undergoes spontaneous retro-Mannich fission to produce a spiro[indoline-3,3-pyrrolenine] with relative configuration defined by the orientation of substituents in the transient cyclobutane. The novel tandem intramolecular photocycloaddition- retro-Mannich (TIPCARM) sequence leads to a spiropyrrolidine which is poised to undergo a second retro-Mannich fragmentation [TIPCA(RM)₂] that expels the malonate unit present in the photo substrate and generates transiently an indolenine. The indolenine undergoes rearrangement to a β-carboline which can undergo further rearrangement under oxidizing conditions to an oxindole. Three oxindole natural products, coerulescine, horsfiline and elacomine, were synthesized using this strategy. The TIPCARM strategy was extended to an approach that would encompass the Vinca alkaloids vindorosine and minovine. In this case, the TIPCARM sequence was followed by an intramolecular cyclization that provided tetracyclic ketone 5.86 containing rings A, B, C and D of vindorosine. A tetracyclic intermediate was synthesized which could also provided access to the Vinca alkaloid minovine. Title: Tandem intramolecular photocycloaddition-retro-Mannich fragmentation as a route to indole and oxindole Author: Li, Yang Irradiation of a tryptamine linked through its side-chain nitrogen to an alkylidene malonate residue results in an intramolecular [2 + 2] cycloaddition to the indole 2,3-double bond. The resultant cyclobutane undergoes spontaneous retro-Mannich fission to produce a spiro[indoline-3,3-pyrrolenine] with relative configuration defined by the orientation of substituents in the transient cyclobutane. The novel tandem intramolecular photocycloaddition- retro-Mannich (TIPCARM) sequence leads to a spiropyrrolidine which is poised to undergo a second retro-Mannich fragmentation [TIPCA(RM)₂] that expels the malonate unit present in the photo substrate and generates transiently an indolenine. The indolenine undergoes rearrangement to a β-carboline which can undergo further rearrangement under oxidizing conditions to an oxindole. Three oxindole natural products, coerulescine, horsfiline and elacomine, were synthesized using this strategy. The TIPCARM strategy was extended to an approach that would encompass the Vinca alkaloids vindorosine and minovine. In this case, the TIPCARM sequence was followed by an intramolecular cyclization that provided tetracyclic ketone 5.86 containing rings A, B, C and D of vindorosine. A tetracyclic intermediate was synthesized which could also provided access to the Vinca alkaloid minovine. Close