Search

Search Results

• 2261. [Article] Impacts of Swiss needle cast on Douglas-fir tree-ring stable isotopes and tree carbohydrate reserves

  Understanding the mechanisms of disease in forest pathology is a critical component to learning how to most efficiently manage tree diseases like Swiss needle cast (SNC). SNC is an economically important, ...

  Citation × Citation Citation Abstract Copy Title: Impacts of Swiss needle cast on Douglas-fir tree-ring stable isotopes and tree carbohydrate reserves Author: Saffell, Brandy J. Understanding the mechanisms of disease in forest pathology is a critical component to learning how to most efficiently manage tree diseases like Swiss needle cast (SNC). SNC is an economically important, fungal disease of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) that is prevalent in coastal areas of the Pacific Northwest. This thesis research provides two contributions to the greater understanding of the pathogenic impacts on plant physiological functioning, or pathophysiology, of SNC on Douglas-fir that will ultimately inform management decisions in Pacific Northwest forests affected by SNC. The primary objectives of this thesis research were: (1) to examine the effects of SNC on Douglas-fir tree-ring stable isotope discrimination of carbon (Δ¹³C) and oxygen (δ¹⁸O) and (2) to evaluate the impact of SNC on tree carbohydrate reserves. Thesis Objective 1- I used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla (Raf.) Sarg.) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. Trees were sampled from a site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of years when disease was present and absent, relative to untreated trees which had the infection throughout. Tree-ring Δ¹³C of treated Douglas-fir increased during the treatment period, and was ~1.6 per mil greater than that of untreated Douglas-fir at the end of the years of the fungicide treatment. Both annual growth and tree-ring Δ¹³C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period, which suggests that the use of Δ¹³C in Douglas-fir tree-rings to track SNC disease history may be a practical approach provided a reference species is available to develop a parallel Δ¹³C chronology. There was no difference in tree-ring δ¹⁸O between treated and untreated Douglas-fir. Tree-ring Δ¹³C of diseased Douglas-fir was negatively correlated with relative humidity (RH) during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that then lead to greater disease severity in following years. Thesis Objective 2- The effects of SNC on Douglas-fir carbohydrate reserves were explored to evaluate the extent to which non-structural carbohydrate (NSC) can be mobilized under natural conditions of low water stress and restricted carbon supply in relation to potential demands for growth. Concentrations of starch, sucrose, glucose and fructose were analyzed in twig wood, foliage, and trunk sapwood of 15 Douglas-fir trees expressing a gradient of SNC symptom severity. There were significant negative relationships between disease severity and growth (mean basal area increment, BAI), as well as between disease severity and mean concentration of trunk NSC. The amount of NSC per unit growth (mean NSC/BAI), an index of the relative priority of storage versus growth, increased with disease severity in all three sampled tissues. These results suggest that under reduced carbon supply with SNC, Douglas-fir trees retain NSC at the expense of growth. The crown retains the most NSC, presumably to maintain foliage growth in the spring to compensate for SNC-induced rapid foliage loss in the summer and fall. Title: Impacts of Swiss needle cast on Douglas-fir tree-ring stable isotopes and tree carbohydrate reserves Author: Saffell, Brandy J. Understanding the mechanisms of disease in forest pathology is a critical component to learning how to most efficiently manage tree diseases like Swiss needle cast (SNC). SNC is an economically important, fungal disease of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) that is prevalent in coastal areas of the Pacific Northwest. This thesis research provides two contributions to the greater understanding of the pathogenic impacts on plant physiological functioning, or pathophysiology, of SNC on Douglas-fir that will ultimately inform management decisions in Pacific Northwest forests affected by SNC. The primary objectives of this thesis research were: (1) to examine the effects of SNC on Douglas-fir tree-ring stable isotope discrimination of carbon (Δ¹³C) and oxygen (δ¹⁸O) and (2) to evaluate the impact of SNC on tree carbohydrate reserves. Thesis Objective 1- I used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla (Raf.) Sarg.) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. Trees were sampled from a site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of years when disease was present and absent, relative to untreated trees which had the infection throughout. Tree-ring Δ¹³C of treated Douglas-fir increased during the treatment period, and was ~1.6 per mil greater than that of untreated Douglas-fir at the end of the years of the fungicide treatment. Both annual growth and tree-ring Δ¹³C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period, which suggests that the use of Δ¹³C in Douglas-fir tree-rings to track SNC disease history may be a practical approach provided a reference species is available to develop a parallel Δ¹³C chronology. There was no difference in tree-ring δ¹⁸O between treated and untreated Douglas-fir. Tree-ring Δ¹³C of diseased Douglas-fir was negatively correlated with relative humidity (RH) during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that then lead to greater disease severity in following years. Thesis Objective 2- The effects of SNC on Douglas-fir carbohydrate reserves were explored to evaluate the extent to which non-structural carbohydrate (NSC) can be mobilized under natural conditions of low water stress and restricted carbon supply in relation to potential demands for growth. Concentrations of starch, sucrose, glucose and fructose were analyzed in twig wood, foliage, and trunk sapwood of 15 Douglas-fir trees expressing a gradient of SNC symptom severity. There were significant negative relationships between disease severity and growth (mean basal area increment, BAI), as well as between disease severity and mean concentration of trunk NSC. The amount of NSC per unit growth (mean NSC/BAI), an index of the relative priority of storage versus growth, increased with disease severity in all three sampled tissues. These results suggest that under reduced carbon supply with SNC, Douglas-fir trees retain NSC at the expense of growth. The crown retains the most NSC, presumably to maintain foliage growth in the spring to compensate for SNC-induced rapid foliage loss in the summer and fall. Close

• 2262. [Article] Genetic and environmental differences in age at first estrus and in wool and lamb production of crossbred ewe lambs

  Genetic and environmental factors affecting age of first estrus, wool production, reproduction and lamb production were examined in eight groups of crossbred ewe lambs from two birth years. The 399 ewe ...

  Citation × Citation Citation Abstract Copy Title: Genetic and environmental differences in age at first estrus and in wool and lamb production of crossbred ewe lambs Author: Cedillo, Rose Mary Genetic and environmental factors affecting age of first estrus, wool production, reproduction and lamb production were examined in eight groups of crossbred ewe lambs from two birth years. The 399 ewe lambs whose first year production was analyzed were from eight crossbred groups resulting from mating North Country Cheviot, Dorset, Finnsheep and Romney rams to Suffolk or whiteface Columbia-type range ewes. The ewe lambs were born January through March of both 1973 and 1974, and were raised to weaning on western Oregon hill pastures. They were summered and maintained through the breeding season on irrigated pastures. At the end of the breeding season each year, ewes within each of the eight groups were randomly divided between hill pasture and irrigated valley pasture management systems. After lambing in common facilities, they were returned to the appropriate management environment where they remained throughout lactation. Average age at first estrus for the 90 percent of ewes which did cycle their first fall was 205 days. Age at estrus between years differed by 18 days (P<.01). Sire breed and the sire x dam breed interaction were not significant effects, but ewes with Suffolk dams cycled ten days earlier than ewes with Columbia dams (P<.01). Also a greater proportion of ewes with Columbia dams failed to cycle their first fall (18 percent versus 2 percent for ewes with Suffolk dams). None of the birth year interactions was significant. The regression of age at estrus on birth date of ewe was -.85 days per day (P<.01). The regression of age at estrus on ewe weight at first estrus (estimated by interpolation between bracketing weights) was 0.39 days per pound (P<.01). The unexpected signs of the two regression coefficients probably resulted from shortened day length in the fall triggering estrus at a fairly constant calendar time but at varying ages and weights, depending upon when the lamb was born the previous spring lambing season. Breed of the ewe's dam significantly affected wool grade with Columbia crosses having finer wool. Staple length was longest and about equal for Finn and Romney sired ewes; Dorset crosses produced the shortest wool. Columbia cross wool was longer than Suffolk cross wool only in Finn and Dorset cross ewes. Grease fleece weight of Columbia crosses was consistently heavier than that of Suffolk crosses. Romney sired ewes had the heaviest fleeces followed by Cheviot, Dorset and Finn sired ewes. Observable medullation was most severe in the two Cheviot crossbred groups, with a tendency for slightly greater medullation in Suffolk than in Columbia crosses. Romney x Columbia ewes generated the most wool income, due to heavy fleece weight and high value per pound of clean wool. Ewes with Columbia dams generated higher wool income than did those with Suffolk dams. The reproductive performance of ewes with Finn sires was superior to that of ewes with Dorset, Cheviot or Romney sires, while ewes with Suffolk dams were superior to ewes with Columbia dams. Finn crossbreds had the greater percentage of ewes lambing per ewe bred (72 percent), while Romney x Columbia ewes were lowest (18 percent). Finn sired crossbred ewes averaged 1.62 lambs born per ewe lambing compared to 1.18 for the average of the other crosses. Finn cross ewes excelled for total weight of lamb weaned, followed by Dorset, Cheviot and Romney sired ewes. The greater lamb production of the Suffolk cross ewes more than compensated for their lower wool production. They generated $6.00 more total gross income than did Columbia crosses. Also for gross income, ewes with Finn sires were highest followed by Dorset, Cheviot and Romney sired ewes. Title: Genetic and environmental differences in age at first estrus and in wool and lamb production of crossbred ewe lambs Author: Cedillo, Rose Mary Genetic and environmental factors affecting age of first estrus, wool production, reproduction and lamb production were examined in eight groups of crossbred ewe lambs from two birth years. The 399 ewe lambs whose first year production was analyzed were from eight crossbred groups resulting from mating North Country Cheviot, Dorset, Finnsheep and Romney rams to Suffolk or whiteface Columbia-type range ewes. The ewe lambs were born January through March of both 1973 and 1974, and were raised to weaning on western Oregon hill pastures. They were summered and maintained through the breeding season on irrigated pastures. At the end of the breeding season each year, ewes within each of the eight groups were randomly divided between hill pasture and irrigated valley pasture management systems. After lambing in common facilities, they were returned to the appropriate management environment where they remained throughout lactation. Average age at first estrus for the 90 percent of ewes which did cycle their first fall was 205 days. Age at estrus between years differed by 18 days (P<.01). Sire breed and the sire x dam breed interaction were not significant effects, but ewes with Suffolk dams cycled ten days earlier than ewes with Columbia dams (P<.01). Also a greater proportion of ewes with Columbia dams failed to cycle their first fall (18 percent versus 2 percent for ewes with Suffolk dams). None of the birth year interactions was significant. The regression of age at estrus on birth date of ewe was -.85 days per day (P<.01). The regression of age at estrus on ewe weight at first estrus (estimated by interpolation between bracketing weights) was 0.39 days per pound (P<.01). The unexpected signs of the two regression coefficients probably resulted from shortened day length in the fall triggering estrus at a fairly constant calendar time but at varying ages and weights, depending upon when the lamb was born the previous spring lambing season. Breed of the ewe's dam significantly affected wool grade with Columbia crosses having finer wool. Staple length was longest and about equal for Finn and Romney sired ewes; Dorset crosses produced the shortest wool. Columbia cross wool was longer than Suffolk cross wool only in Finn and Dorset cross ewes. Grease fleece weight of Columbia crosses was consistently heavier than that of Suffolk crosses. Romney sired ewes had the heaviest fleeces followed by Cheviot, Dorset and Finn sired ewes. Observable medullation was most severe in the two Cheviot crossbred groups, with a tendency for slightly greater medullation in Suffolk than in Columbia crosses. Romney x Columbia ewes generated the most wool income, due to heavy fleece weight and high value per pound of clean wool. Ewes with Columbia dams generated higher wool income than did those with Suffolk dams. The reproductive performance of ewes with Finn sires was superior to that of ewes with Dorset, Cheviot or Romney sires, while ewes with Suffolk dams were superior to ewes with Columbia dams. Finn crossbreds had the greater percentage of ewes lambing per ewe bred (72 percent), while Romney x Columbia ewes were lowest (18 percent). Finn sired crossbred ewes averaged 1.62 lambs born per ewe lambing compared to 1.18 for the average of the other crosses. Finn cross ewes excelled for total weight of lamb weaned, followed by Dorset, Cheviot and Romney sired ewes. The greater lamb production of the Suffolk cross ewes more than compensated for their lower wool production. They generated $6.00 more total gross income than did Columbia crosses. Also for gross income, ewes with Finn sires were highest followed by Dorset, Cheviot and Romney sired ewes. Close

• 2263. [Article] Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia

  This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were ...

  Citation × Citation Citation Abstract Copy Title: Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia Author: Basuki, Imam This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5 m), Ketapang Regency, West Kalimantan, Indonesia. The objectives of this study were: a). to quantify C stocks of tropical coastal peat swamp forest, and the potential impact of forest degradation due to draining and logging activities on the forest’s carbon stocks; b). to examine the change in ecosystem C stocks and the potential C emissions in relation to land conversion from intact peat swamp forest (PSF) to logged peat forest (LPSF), early seral (ES) and oil palm plantation (OP); and c). to estimate net primary production (NPP) and net ecosystem production (NEP) in peat swamp forests, logged peat forest, early seral and smallholder - oil palm plantations. The intact peat forest sites have higher total aboveground C stocks (125 Mg C ha-1) than the logged peat forest sites (77 Mg C ha-1). Mean depths of the LPSF was 725 cm and the PSF was 915 cm (p= 0.06). Mean peat carbon stocks at PSF was 4,243 Mg C ha-1, higher than at LPSF that was 3,675 Mg C ha-1. Logging and draining had reduced the biomass of trees and the peat carbon pools. My study demonstrated that tropical coastal PSF has the largest total carbon stocks among terrestrial ecosystems on earth. The large carbon stocks and high rates of PSF degradation, points to the relevance for inclusion of PSF in nationally appropriate climate change mitigation and adaptation strategies. The mean ecosystem carbon stock for the PSF sites was 4,401 Mg C ha-1. Ecosystem C stocks of LPSF, ES and OP was 3,768, 3,147, and 3,442 Mg C ha-1, respectively. PSF stocks was significantly higher than the degraded land covers. At all sites, soils comprised > 96% of the mean ecosystem carbon stock. Using the estimation based on ecosystem carbon loss to total peat depths, the conversion of PSF to LPSF, ES and OP was estimated to result in a net loss of 1,982, 4,259 and 3,176 Mg C-CO2 ha-1, respectively. My results confirm that land cover change significantly impacted soil properties and reduced ecosystem carbon stocks. The tropical peatlands need urgent and significant efforts in conservation and restoration, to regain its function as a C sink and mitigate climate change. I found that land use/land cover change resulted in large shifts in NPP and NEP. LPSF, ES and OP have significantly lower NPP (11.1 Mg C ha-1 yr-1, 10.8 Mg C ha-1 yr-1 and 3.7 Mg C ha-1 yr-1, respectively) than PSF (13.2 Mg C ha-1 yr-1). ES showed lower heterotrophic respiration (30.7 Mg CO2 ha-1 yr-1) than PSF, LPSF and OP (37.7 Mg CO2 ha-1 yr-1, 40.7 Mg CO2 ha-1 yr-1, 38.7 Mg CO2 ha-1 yr-1, respectively). LPSF and OP were net carbon sources; they have negative mean NEP values (-0.1 Mg CO2-e ha-1 yr-1 and -25.1 Mg CO2-e ha-1 yr-1, respectively). In contrast PSF and ES were net carbon sinks (10.8 Mg CO2-e ha-1 yr-1 and 9.1 CCO2 ha-1 yr-1, respectively). PSF is among the most productive of terrestrial ecosystems, with an NPP exceeding that of many tropical rain forests and similar to the most productive mangrove ecosystems. I found that land use decreases productivity of the LPSF and OP sites. The ES had a similar NEP to the PSF, but frequent fires in this ecosystem likely offset carbon gains during the fire intervals. Land use change and forest degradation have shifted tropical PSFs from net carbon sinks to net carbon sources. My study demonstrated that land conversion in tropical peat swamp forests should be halted and degraded peatlands need to be restored in order to mitigate climate change. Title: Carbon Dynamics in Response to Land Cover Change in Tropical Peatlands, Kalimantan, Indonesia Author: Basuki, Imam This study focuses in providing the knowledge on carbon (C) stocks, emission and ecosystem productivity related to land use/land cover change in tropical peatlands. The field research activities were conducted for about 17 months between August 2013 to December 2015, at Pematang Gadung peat dome (peat depth up to 10.5 m), Ketapang Regency, West Kalimantan, Indonesia. The objectives of this study were: a). to quantify C stocks of tropical coastal peat swamp forest, and the potential impact of forest degradation due to draining and logging activities on the forest’s carbon stocks; b). to examine the change in ecosystem C stocks and the potential C emissions in relation to land conversion from intact peat swamp forest (PSF) to logged peat forest (LPSF), early seral (ES) and oil palm plantation (OP); and c). to estimate net primary production (NPP) and net ecosystem production (NEP) in peat swamp forests, logged peat forest, early seral and smallholder - oil palm plantations. The intact peat forest sites have higher total aboveground C stocks (125 Mg C ha-1) than the logged peat forest sites (77 Mg C ha-1). Mean depths of the LPSF was 725 cm and the PSF was 915 cm (p= 0.06). Mean peat carbon stocks at PSF was 4,243 Mg C ha-1, higher than at LPSF that was 3,675 Mg C ha-1. Logging and draining had reduced the biomass of trees and the peat carbon pools. My study demonstrated that tropical coastal PSF has the largest total carbon stocks among terrestrial ecosystems on earth. The large carbon stocks and high rates of PSF degradation, points to the relevance for inclusion of PSF in nationally appropriate climate change mitigation and adaptation strategies. The mean ecosystem carbon stock for the PSF sites was 4,401 Mg C ha-1. Ecosystem C stocks of LPSF, ES and OP was 3,768, 3,147, and 3,442 Mg C ha-1, respectively. PSF stocks was significantly higher than the degraded land covers. At all sites, soils comprised > 96% of the mean ecosystem carbon stock. Using the estimation based on ecosystem carbon loss to total peat depths, the conversion of PSF to LPSF, ES and OP was estimated to result in a net loss of 1,982, 4,259 and 3,176 Mg C-CO2 ha-1, respectively. My results confirm that land cover change significantly impacted soil properties and reduced ecosystem carbon stocks. The tropical peatlands need urgent and significant efforts in conservation and restoration, to regain its function as a C sink and mitigate climate change. I found that land use/land cover change resulted in large shifts in NPP and NEP. LPSF, ES and OP have significantly lower NPP (11.1 Mg C ha-1 yr-1, 10.8 Mg C ha-1 yr-1 and 3.7 Mg C ha-1 yr-1, respectively) than PSF (13.2 Mg C ha-1 yr-1). ES showed lower heterotrophic respiration (30.7 Mg CO2 ha-1 yr-1) than PSF, LPSF and OP (37.7 Mg CO2 ha-1 yr-1, 40.7 Mg CO2 ha-1 yr-1, 38.7 Mg CO2 ha-1 yr-1, respectively). LPSF and OP were net carbon sources; they have negative mean NEP values (-0.1 Mg CO2-e ha-1 yr-1 and -25.1 Mg CO2-e ha-1 yr-1, respectively). In contrast PSF and ES were net carbon sinks (10.8 Mg CO2-e ha-1 yr-1 and 9.1 CCO2 ha-1 yr-1, respectively). PSF is among the most productive of terrestrial ecosystems, with an NPP exceeding that of many tropical rain forests and similar to the most productive mangrove ecosystems. I found that land use decreases productivity of the LPSF and OP sites. The ES had a similar NEP to the PSF, but frequent fires in this ecosystem likely offset carbon gains during the fire intervals. Land use change and forest degradation have shifted tropical PSFs from net carbon sinks to net carbon sources. My study demonstrated that land conversion in tropical peat swamp forests should be halted and degraded peatlands need to be restored in order to mitigate climate change. Close

• 2264. [Article] Scaffold reactivity and large scale Synthesis of organocatalyzed Yamada-Otani Condensation product and investigation of the synthesis and properties of axially chiral 8,8'-biquinolyls and 8-(naphtha-1-yl)quinolines

  In Part I, (4S,5R)-4,5-dimethyl-4-phenylcyclohex-2-enone (19a) was prepared in 73% yield with high enantio- and diastereo-selectivity (er > 98:2, dr > 20:1) on a multigram scale by a Yamada-Otani condensation ...

  Citation × Citation Citation Abstract Copy Title: Scaffold reactivity and large scale Synthesis of organocatalyzed Yamada-Otani Condensation product and investigation of the synthesis and properties of axially chiral 8,8'-biquinolyls and 8-(naphtha-1-yl)quinolines Author: Banerjee, Somdev In Part I, (4S,5R)-4,5-dimethyl-4-phenylcyclohex-2-enone (19a) was prepared in 73% yield with high enantio- and diastereo-selectivity (er > 98:2, dr > 20:1) on a multigram scale by a Yamada-Otani condensation between (E)-pent-3-en-2-one and 2-phenylpropanal catalyzed by a sulfonimide derivative of (S)-proline (18, HuaCat®). Synthetically useful transformations of the cyclohexenone product 19a were demonstrated, as follows: (a) alpha-alkylation via Li-enolate formation (e.g., LDA, DMPU, MeI, THF, –78 °C, 2 h; 86% yield, dr > 20:1), (b) 1,2-addition of organolithiums (e.g., PhLi, THF, –78 °C, 2 h; 82% yield, dr > 20:1), and (c) 1,4-addition of cyanocuprates (e.g., n-BuLi, CuCN, THF, –78 °C, 2 h; 90% yield, dr > 20:1). In Part II, an azaanalog of 1,1´-bi-2-naphthol (BINOL, 38), 7-hydroxy-8-(2-hydroxynaphth-1-yl)quinoline (8-azaBINOL, 67), was prepared in 3 steps and 49% yield from N,N-diethyl O-(7-hydroxy-8-iodoquinolyl) carbamate via Suzuki coupling with 1-naphthyl-boronic acid followed by Sanford oxidation and saponification. 8- AzaBINOL (67) was resolved into (–)-(aS) and (+)-(aR) atropisomers by enzymatic hydrolysis of its racemic divalerate derivative with bovine pancreas acetone powder. The configurational stability of 8-azaBINOL (67) was found to be intermediate to that of 7,7´-dihydroxy-8,8´-biquinolyl ('8,8´-diazaBINOL', 50, least stable) and BINOL (38, most stable). Eyring plot analysis of the enantiomerization kinetics of 50, 67, and 38, in DMSO solution revealed activation parameters of ΔH‡ = +27.4, +19.9, +23.2 kcal mol–1, and ΔS‡ = +3.8, –27.9, –25.3 cal mol–1 K–1, respectively. The unique character of ΔH‡ and ΔS‡ values for biquinolyl 50 suggests that the enantiomerization mechanism for 50 is distinct to that for naphthalenes 67 and 38. Monohydroxy analogs of 67, 7-hydroxy-8-(naphth-1-yl)quinoline (71) and 8-(2-hydroxynaphth-1-yl)quinoline (75), were similarly prepared and their racemization half-lives at rt were determined; τ1/2(rac.) was strongly dependent on solvent for naphthol 75 (τ1/2(rac.) at 24 °C: in CHCl3 = 2.7 h, in MeOH = 89 h) but not for the quinol 71 (τ1/2(rac.) at 24 °C: in CHCl3 = 106 h, in MeOH = 120 h). 8-AzaBINOL (67) and its tosylic acid salt (67•TsOH) were evaluated as potential hydrogen-bonding / Brønsted acid organocatalysts for enantioselective carbon-carbon bond forming processes. Neither form of the compound was an effective catalyst for the Henry reaction between nitromethane and benzaldehyde nor the conjugate addition of acetylacetone to beta-nitrostyrene; however, these quinols did promote the addition of nucleophilic arenes to pyruvate esters (albeit with low enantioselectivity). For example, addition of indole to ethyl trifluoropyruvate (Et2O, –78 °C) gave the expected beta-substituted indole product [(S)-87] in 98% yield and with 5% ee in the presence of free base (S)-67 (10 mol%). The same organocatalyst did not promote addition of indole to ethyl pyruvate (Et2O, –40 °C) but its more reactive tosylate salt (S)-67•TsOH did, resulting in an 82% yield of the addition product with 3% ee. In a collaborative study (with R. Overacker and S. Loesgen), a 45-member library of 8-azaBINOL and 8,8´-diazaBINOL derivatives was evaluated for biological activity in cytotoxicity/cell viability and HIV viral entry inhibition assays. The isopropyl ether of 7-hydroxy-8-(naphth-1-yl)quinoline (92) and the analogous N,N-diethyl carbamate (69) exhibited the most significant bioactivity with respective IC50 = 4.74 μM and 5.18 μM for inhibition of HIV-1 entry into TZM-b1 cells. Comparable 8,8´-diazaBINOLs did not inhibit viral entry. Specific binding of isopropyl ether 92 to purified and immobilized HIV-1 glycoprotein 120 with a KD = 22 ± 2.9 μM was established using biolayer interferometry. Title: Scaffold reactivity and large scale Synthesis of organocatalyzed Yamada-Otani Condensation product and investigation of the synthesis and properties of axially chiral 8,8'-biquinolyls and 8-(naphtha-1-yl)quinolines Author: Banerjee, Somdev In Part I, (4S,5R)-4,5-dimethyl-4-phenylcyclohex-2-enone (19a) was prepared in 73% yield with high enantio- and diastereo-selectivity (er > 98:2, dr > 20:1) on a multigram scale by a Yamada-Otani condensation between (E)-pent-3-en-2-one and 2-phenylpropanal catalyzed by a sulfonimide derivative of (S)-proline (18, HuaCat®). Synthetically useful transformations of the cyclohexenone product 19a were demonstrated, as follows: (a) alpha-alkylation via Li-enolate formation (e.g., LDA, DMPU, MeI, THF, –78 °C, 2 h; 86% yield, dr > 20:1), (b) 1,2-addition of organolithiums (e.g., PhLi, THF, –78 °C, 2 h; 82% yield, dr > 20:1), and (c) 1,4-addition of cyanocuprates (e.g., n-BuLi, CuCN, THF, –78 °C, 2 h; 90% yield, dr > 20:1). In Part II, an azaanalog of 1,1´-bi-2-naphthol (BINOL, 38), 7-hydroxy-8-(2-hydroxynaphth-1-yl)quinoline (8-azaBINOL, 67), was prepared in 3 steps and 49% yield from N,N-diethyl O-(7-hydroxy-8-iodoquinolyl) carbamate via Suzuki coupling with 1-naphthyl-boronic acid followed by Sanford oxidation and saponification. 8- AzaBINOL (67) was resolved into (–)-(aS) and (+)-(aR) atropisomers by enzymatic hydrolysis of its racemic divalerate derivative with bovine pancreas acetone powder. The configurational stability of 8-azaBINOL (67) was found to be intermediate to that of 7,7´-dihydroxy-8,8´-biquinolyl ('8,8´-diazaBINOL', 50, least stable) and BINOL (38, most stable). Eyring plot analysis of the enantiomerization kinetics of 50, 67, and 38, in DMSO solution revealed activation parameters of ΔH‡ = +27.4, +19.9, +23.2 kcal mol–1, and ΔS‡ = +3.8, –27.9, –25.3 cal mol–1 K–1, respectively. The unique character of ΔH‡ and ΔS‡ values for biquinolyl 50 suggests that the enantiomerization mechanism for 50 is distinct to that for naphthalenes 67 and 38. Monohydroxy analogs of 67, 7-hydroxy-8-(naphth-1-yl)quinoline (71) and 8-(2-hydroxynaphth-1-yl)quinoline (75), were similarly prepared and their racemization half-lives at rt were determined; τ1/2(rac.) was strongly dependent on solvent for naphthol 75 (τ1/2(rac.) at 24 °C: in CHCl3 = 2.7 h, in MeOH = 89 h) but not for the quinol 71 (τ1/2(rac.) at 24 °C: in CHCl3 = 106 h, in MeOH = 120 h). 8-AzaBINOL (67) and its tosylic acid salt (67•TsOH) were evaluated as potential hydrogen-bonding / Brønsted acid organocatalysts for enantioselective carbon-carbon bond forming processes. Neither form of the compound was an effective catalyst for the Henry reaction between nitromethane and benzaldehyde nor the conjugate addition of acetylacetone to beta-nitrostyrene; however, these quinols did promote the addition of nucleophilic arenes to pyruvate esters (albeit with low enantioselectivity). For example, addition of indole to ethyl trifluoropyruvate (Et2O, –78 °C) gave the expected beta-substituted indole product [(S)-87] in 98% yield and with 5% ee in the presence of free base (S)-67 (10 mol%). The same organocatalyst did not promote addition of indole to ethyl pyruvate (Et2O, –40 °C) but its more reactive tosylate salt (S)-67•TsOH did, resulting in an 82% yield of the addition product with 3% ee. In a collaborative study (with R. Overacker and S. Loesgen), a 45-member library of 8-azaBINOL and 8,8´-diazaBINOL derivatives was evaluated for biological activity in cytotoxicity/cell viability and HIV viral entry inhibition assays. The isopropyl ether of 7-hydroxy-8-(naphth-1-yl)quinoline (92) and the analogous N,N-diethyl carbamate (69) exhibited the most significant bioactivity with respective IC50 = 4.74 μM and 5.18 μM for inhibition of HIV-1 entry into TZM-b1 cells. Comparable 8,8´-diazaBINOLs did not inhibit viral entry. Specific binding of isopropyl ether 92 to purified and immobilized HIV-1 glycoprotein 120 with a KD = 22 ± 2.9 μM was established using biolayer interferometry. Close

• 2265. [Article] Carboxylesterases in the house fly (Musca domestica, L.), flesh fly (Sarcophaga bullata, Park.), and black blow fly (Phormia regina, Meig.)

  The carboxylesterases of three species of diptera, the flesh fly (Sarcophaga bullata, Park.), the black blow fly (Phormia regina, Meig.), and the house fly (Musca domestica, L.) were compared in relation to ...

  Citation × Citation Citation Abstract Copy Title: Carboxylesterases in the house fly (Musca domestica, L.), flesh fly (Sarcophaga bullata, Park.), and black blow fly (Phormia regina, Meig.) Author: Maa, Can-jen William The carboxylesterases of three species of diptera, the flesh fly (Sarcophaga bullata, Park.), the black blow fly (Phormia regina, Meig.), and the house fly (Musca domestica, L.) were compared in relation to hydrolytic activity against three substrates, response to inhibition and induction, isozyme composition, and age-dependent variation in activity. Similar studies were also conducted with an insecticide-resistant house fly strain. Most of the experiments were with adult female flies but male flies as well as larvae and pupae were included in several experiments. Naphthyl acetate was the substrate common to all experiments and the esterases hydrolyzing this compound were further characterized according to their inhibition by eserine, parahydroxymecuribenzoate (PHNB), and paraoxon. The hydrolytic activity observed in the presence of eserine and PHNB or blocked by paraoxon was considered to be due to carboxylesterases of the B-type. Two other esters, hydroprene, an insect growth regulator similar in structure to the natural juvenile hormone, and juvenile hormone-1, were also used as substrates. Neither the hemolymph nor the cytosol esterases of the three species were susceptible to eserine inhibition, indicating that the samples contained minor quantities of the choline esterases. PHNB had little inhibitory effect on the flesh fly esterases of both hemolymph and soluble fraction. However, this inhibitor reduced the activity of the blow fly esterases by more than 50 percent, indicating a high content of aryl esterases in this species. The house fly esterases were also inhibited by PHNB but to a less extent than those of the blow fly. As expected, paraoxon was a strong inhibitor of the esterases in both hemolymph and soluble fraction of the three species. The total enzyme content of the flies was estimated from the hemolymph volumes determined earlier and the activity per unit volume found in the age-dependency experiments. The daily average activity estimated in this way was highest in the flesh fly, about four times that of the blow fly, and lowest in the house fly, about one-seventh that of the flesh fly. The values were even lower in the case of the resistant house flies, about 1/40th those of the flesh fly. When hydroprene was used as a substrate in the age-dependency experiments, the activity profiles were similar to those found with naphthyl acetate as substrate indicating that the same enzymes were involved in the hydrolysis of this JH analogue. Of the three species, the flesh fly esterases were most active against hydroprene and the blow fly and resistant house fly enzymes were the least active. The flesh fly hemolymph enzymes averaged, on a per-day basis, up to three times more hydroprene cleaving activity than those of the resistant house flies. The electrophorese experiments with hemolymph and cytosol revealed the presence of several carboxylesterase isozymes. As many as 14 different esterase-active bands were found in flesh fly hemolymph, 11 in blow fly hemolymph, and 12 in house fly hemolymph. Similar results were obtained with the cytosol. These bands were placed in five groups according to their mobilities in the poly acrylamide gels and it was evident that the isozymes migrating to the midpoint of the gels were responsible for most of the carboxylesterase activity. Some slow-moving isozymes were also thought to be responsible for this type of activity. Other evidence obtained during the electrophoreses experiments indicated that the isozymes hydrolizing hydroprene were from the same groups as those cleaving naphthyl-acetate while those which attacked JH-1 had different electrophoretic characteristics. Both hydroprene and naphthyl acetate esterases were induced by topically applied hydroprene. The response was dose dependent in the range 1-10 ug for flesh flies and 1-5 ug for house flies and blow flies. However, the response was variable and appeared to depend on the age of the flies at the time of the treatment. Increases in esterase activity ranged from 1.5 to 4-fold with the flesh fly enzymes being the most responsive and those of the blow fly the least. The possibility of JH-1 esterase induction by hydroprene was not investigated. Title: Carboxylesterases in the house fly (Musca domestica, L.), flesh fly (Sarcophaga bullata, Park.), and black blow fly (Phormia regina, Meig.) Author: Maa, Can-jen William The carboxylesterases of three species of diptera, the flesh fly (Sarcophaga bullata, Park.), the black blow fly (Phormia regina, Meig.), and the house fly (Musca domestica, L.) were compared in relation to hydrolytic activity against three substrates, response to inhibition and induction, isozyme composition, and age-dependent variation in activity. Similar studies were also conducted with an insecticide-resistant house fly strain. Most of the experiments were with adult female flies but male flies as well as larvae and pupae were included in several experiments. Naphthyl acetate was the substrate common to all experiments and the esterases hydrolyzing this compound were further characterized according to their inhibition by eserine, parahydroxymecuribenzoate (PHNB), and paraoxon. The hydrolytic activity observed in the presence of eserine and PHNB or blocked by paraoxon was considered to be due to carboxylesterases of the B-type. Two other esters, hydroprene, an insect growth regulator similar in structure to the natural juvenile hormone, and juvenile hormone-1, were also used as substrates. Neither the hemolymph nor the cytosol esterases of the three species were susceptible to eserine inhibition, indicating that the samples contained minor quantities of the choline esterases. PHNB had little inhibitory effect on the flesh fly esterases of both hemolymph and soluble fraction. However, this inhibitor reduced the activity of the blow fly esterases by more than 50 percent, indicating a high content of aryl esterases in this species. The house fly esterases were also inhibited by PHNB but to a less extent than those of the blow fly. As expected, paraoxon was a strong inhibitor of the esterases in both hemolymph and soluble fraction of the three species. The total enzyme content of the flies was estimated from the hemolymph volumes determined earlier and the activity per unit volume found in the age-dependency experiments. The daily average activity estimated in this way was highest in the flesh fly, about four times that of the blow fly, and lowest in the house fly, about one-seventh that of the flesh fly. The values were even lower in the case of the resistant house flies, about 1/40th those of the flesh fly. When hydroprene was used as a substrate in the age-dependency experiments, the activity profiles were similar to those found with naphthyl acetate as substrate indicating that the same enzymes were involved in the hydrolysis of this JH analogue. Of the three species, the flesh fly esterases were most active against hydroprene and the blow fly and resistant house fly enzymes were the least active. The flesh fly hemolymph enzymes averaged, on a per-day basis, up to three times more hydroprene cleaving activity than those of the resistant house flies. The electrophorese experiments with hemolymph and cytosol revealed the presence of several carboxylesterase isozymes. As many as 14 different esterase-active bands were found in flesh fly hemolymph, 11 in blow fly hemolymph, and 12 in house fly hemolymph. Similar results were obtained with the cytosol. These bands were placed in five groups according to their mobilities in the poly acrylamide gels and it was evident that the isozymes migrating to the midpoint of the gels were responsible for most of the carboxylesterase activity. Some slow-moving isozymes were also thought to be responsible for this type of activity. Other evidence obtained during the electrophoreses experiments indicated that the isozymes hydrolizing hydroprene were from the same groups as those cleaving naphthyl-acetate while those which attacked JH-1 had different electrophoretic characteristics. Both hydroprene and naphthyl acetate esterases were induced by topically applied hydroprene. The response was dose dependent in the range 1-10 ug for flesh flies and 1-5 ug for house flies and blow flies. However, the response was variable and appeared to depend on the age of the flies at the time of the treatment. Increases in esterase activity ranged from 1.5 to 4-fold with the flesh fly enzymes being the most responsive and those of the blow fly the least. The possibility of JH-1 esterase induction by hydroprene was not investigated. Close

• 2266. [Article] Geochemistry of Plutonic Rocks of the Western Cascades, Washington & Oregon : Relationship to Crustal Segmentation and Ore Genesis

  The volcanic (~45-10 Ma) and plutonic rocks (~37-12 Ma) comprising the Western Cascades extend from northernmost California to southern British Columbia and are ancestral to modern arc magmatism. The ancestral ...

  Citation × Citation Citation Abstract Copy Title: Geochemistry of Plutonic Rocks of the Western Cascades, Washington & Oregon : Relationship to Crustal Segmentation and Ore Genesis Author: Utevsky, Elinor S. The volcanic (~45-10 Ma) and plutonic rocks (~37-12 Ma) comprising the Western Cascades extend from northernmost California to southern British Columbia and are ancestral to modern arc magmatism. The ancestral arc hosts a series of small plutons that are locally associated with porphyry (Cu-Mo) and epithermal (Au) ore deposits. Three crustal segments identified by Schmidt et al. (2008, 2013) in the modern arc are potentially reflected in the geochemistry of the ancestral Cascades as well: Paleozoic-Mesozoic accreted terranes, metamorphic rocks, and granites to the north; thin Paleocene Siletzia oceanic crust of the Columbia Embayment in the center; and Paleozoic-Mesozoic ultramafic sheets and marine arc-related volcanic and sedimentary rocks of the Klamath Terrane to the south. Therefore, the Western Cascades of Washington and Oregon provide a field laboratory to examine the chemical compositions and ages of granitoid intrusions associated with a variety of magmatic-hydrothermal ore deposits, and to compare the compositions with the along-arc variation of the age, composition and thickness of the underlying crust. The majority of the 15 new zircon U-Pb ages reported in this study are 27 to 12 Ma with the exception of the ~37 Ma Snoqualmie North Fork intrusions of central WA. A total of 610 zircons were analyzed, of which 118 have ages older than the main population and are considered to be xenocrystic or inherited. The north segment contains the oldest (up to 67 Ma) and most continuous inherited population. The absence of inherited grains older than 67 Ma suggests that neither the North Fork nor White River districts overlie old crystalline crust, but instead overlie Paleocene-Eocene volcanics that are the likely source of inherited zircons. Districts of the Columbia segment have sparse inherited zircon populations (n = 38 of 350 total), ranging from 54 to 20 Ma. The dearth of inherited zircons in the center of the arc suggests limited contamination by a source no older than 55 Ma, likely the dominant Eocene sources of detrital zircon found within the Tyee Formation. Districts overlying the Klamath Terrane have slightly more substantial inherited zircon populations than districts overlying Siletzia but still decidedly few inherited grains (a total of 25 out of 85 grains analyzed, ranging from 44 to 19 Ma); these grains are likely sourced from similar contaminants to those underlying the central segment of the arc, instead of from accreted Mesozoic rocks of the Klamath Terrane. The hypabyssal plutonic rocks represent a small area (~1%) of exposures in the Western Cascades, and range in composition from diorites to granodiorites and minor granite. Fe-Ti oxides, where preserved, include magnetite and ilmenite in proportion of ~2:1, and together with presence of hornblende and biotite are suggestive of modest oxidation states of ~ ΔNNO of 0 to 1 (Carmichael & Nicholls, 1967). Abundant hornblende is observed in 31 of 36 available petrographic sections. Ba/Nb values are not obviously correlated with SiO₂ content from any given district, but tend to increase at any given SiO₂ content from north to south. Th/Ta ratios notably increase with SiO₂, and are lowest in the mid-latitude districts (North Santiam, Detroit Dam, Quartzville, and Blue River). While increased slab fluid could increase Ba relative to Nb, the greater abundance of Ba, Th, and Th/Ta southward at given SiO₂ are more consistent with an increased role of crustal contamination. Dy/Yb ratios decrease with increasing SiO₂ contents with the exception of the North Fork District. V/Sc ratios decrease with increasing SiO₂ with the exception of samples of the Spirit Lake Pluton, and slightly increase from south to north at any given SiO₂ content. Zircons in the Western Cascades plutonic rocks have characteristically large negative Eu anomalies (Eu/Eu* < 0.5) and small positive Ce anomalies, correlated with relatively reduced oxidation states and low water contents, even when directly associated with moderately economic porphyry Cu deposits. Although these magmas are sufficiently water-rich to abundantly crystallize and fractionate amphibole (at least 3 wt. % H₂O), it is evident that plagioclase likely crystallized early and was not suppressed by high water contents (> 3 wt. % H₂O). There is no evidence that Western Cascade magmas were strongly oxidized (> NNO +1). Although crustal thickness is poorly constrained in the north and south segments, it is evidently variable along-arc (and may thicken slightly to the south), but is likely relatively thin. I therefore suggest that crustal thickness and lithology substantially control ore potential within the Western Cascade Arc. Title: Geochemistry of Plutonic Rocks of the Western Cascades, Washington & Oregon : Relationship to Crustal Segmentation and Ore Genesis Author: Utevsky, Elinor S. The volcanic (~45-10 Ma) and plutonic rocks (~37-12 Ma) comprising the Western Cascades extend from northernmost California to southern British Columbia and are ancestral to modern arc magmatism. The ancestral arc hosts a series of small plutons that are locally associated with porphyry (Cu-Mo) and epithermal (Au) ore deposits. Three crustal segments identified by Schmidt et al. (2008, 2013) in the modern arc are potentially reflected in the geochemistry of the ancestral Cascades as well: Paleozoic-Mesozoic accreted terranes, metamorphic rocks, and granites to the north; thin Paleocene Siletzia oceanic crust of the Columbia Embayment in the center; and Paleozoic-Mesozoic ultramafic sheets and marine arc-related volcanic and sedimentary rocks of the Klamath Terrane to the south. Therefore, the Western Cascades of Washington and Oregon provide a field laboratory to examine the chemical compositions and ages of granitoid intrusions associated with a variety of magmatic-hydrothermal ore deposits, and to compare the compositions with the along-arc variation of the age, composition and thickness of the underlying crust. The majority of the 15 new zircon U-Pb ages reported in this study are 27 to 12 Ma with the exception of the ~37 Ma Snoqualmie North Fork intrusions of central WA. A total of 610 zircons were analyzed, of which 118 have ages older than the main population and are considered to be xenocrystic or inherited. The north segment contains the oldest (up to 67 Ma) and most continuous inherited population. The absence of inherited grains older than 67 Ma suggests that neither the North Fork nor White River districts overlie old crystalline crust, but instead overlie Paleocene-Eocene volcanics that are the likely source of inherited zircons. Districts of the Columbia segment have sparse inherited zircon populations (n = 38 of 350 total), ranging from 54 to 20 Ma. The dearth of inherited zircons in the center of the arc suggests limited contamination by a source no older than 55 Ma, likely the dominant Eocene sources of detrital zircon found within the Tyee Formation. Districts overlying the Klamath Terrane have slightly more substantial inherited zircon populations than districts overlying Siletzia but still decidedly few inherited grains (a total of 25 out of 85 grains analyzed, ranging from 44 to 19 Ma); these grains are likely sourced from similar contaminants to those underlying the central segment of the arc, instead of from accreted Mesozoic rocks of the Klamath Terrane. The hypabyssal plutonic rocks represent a small area (~1%) of exposures in the Western Cascades, and range in composition from diorites to granodiorites and minor granite. Fe-Ti oxides, where preserved, include magnetite and ilmenite in proportion of ~2:1, and together with presence of hornblende and biotite are suggestive of modest oxidation states of ~ ΔNNO of 0 to 1 (Carmichael & Nicholls, 1967). Abundant hornblende is observed in 31 of 36 available petrographic sections. Ba/Nb values are not obviously correlated with SiO₂ content from any given district, but tend to increase at any given SiO₂ content from north to south. Th/Ta ratios notably increase with SiO₂, and are lowest in the mid-latitude districts (North Santiam, Detroit Dam, Quartzville, and Blue River). While increased slab fluid could increase Ba relative to Nb, the greater abundance of Ba, Th, and Th/Ta southward at given SiO₂ are more consistent with an increased role of crustal contamination. Dy/Yb ratios decrease with increasing SiO₂ contents with the exception of the North Fork District. V/Sc ratios decrease with increasing SiO₂ with the exception of samples of the Spirit Lake Pluton, and slightly increase from south to north at any given SiO₂ content. Zircons in the Western Cascades plutonic rocks have characteristically large negative Eu anomalies (Eu/Eu* < 0.5) and small positive Ce anomalies, correlated with relatively reduced oxidation states and low water contents, even when directly associated with moderately economic porphyry Cu deposits. Although these magmas are sufficiently water-rich to abundantly crystallize and fractionate amphibole (at least 3 wt. % H₂O), it is evident that plagioclase likely crystallized early and was not suppressed by high water contents (> 3 wt. % H₂O). There is no evidence that Western Cascade magmas were strongly oxidized (> NNO +1). Although crustal thickness is poorly constrained in the north and south segments, it is evidently variable along-arc (and may thicken slightly to the south), but is likely relatively thin. I therefore suggest that crustal thickness and lithology substantially control ore potential within the Western Cascade Arc. Close

• 2267. [Article] Adaptive Multiagent Traffic Management for Autonomous Robotic Systems

  There is growing commercial interest in the use of unmanned aerial vehicles (UAVs) in urban environments, specifically for package delivery applications. However, the size, complexity and sheer numbers ...

  Citation × Citation Citation Abstract Copy Title: Adaptive Multiagent Traffic Management for Autonomous Robotic Systems Author: Rebhuhn, Carrie There is growing commercial interest in the use of unmanned aerial vehicles (UAVs) in urban environments, specifically for package delivery applications. However, the size, complexity and sheer numbers of expected UAVs makes conventional air traffic management that relies on human air traffic controllers infeasible. To enable UAVs to safely and efficiently operate in congested environments, it is essential to develop autonomous UAV management strategies. We introduce a dynamic hierarchical traffic control model that reacts to traffic conditions instantaneously to reduce congestion in the airspace. An obstacle-filled airspace lends itself to a modelling as a graph structure similar to a road network. We introduce controller agents, which set costs across the airspace. These agents control traffic similarly to adaptive metering lights in highway traffic. UAVs then plan their paths based on the costs (e.g. conflicts, or delays) they see for traversing particular parts of the airspace. This provides us a decentralized method for reducing traffic in an airspace Our hierarchical structure allows us to separate the traffic reduction problem from the individual robot navigation problem. Each robot does not explicitly coordinate with others in the airspace. Instead, robots execute their own individual internal cost-based planner to travel between locations. We then use neuro-evolution to provide incentives to these cost-based planners to reduce traffic in the environment. Traffic quality can be expressed in several different ways. We first evaluate traffic our traffic reduction policies in terms of `conflicts', which characterizes situations where an aircraft comes too close to another for safety in a physical space. We then examine traffic in terms of the amount of `delay' that all agents incur, which assumes that there is a structure to ensure only a safe number of UAVs occupy the same area. Finally, we look at the total travel time that a UAV can expect to take from the moment it enters the airspace until the time it gets to its destination. To facilitate an exploration of the UTM problem without waiting for a full simulation of UAVS running with A* , we develop an abstraction of the UTM domain that preserves the core UTM problem. We then investigate performance under differing levels of traffic, a well as two different agent structures. Our results show similar performance for both agent definitions, with delay reduction of up to 68% in high traffic cases. With a fast version of the UTM problem, we explore the effect of redefining the control structure such that links, or edges of the UTM graph, set costs individually. This shifts the control paradigm toward controlling directional travel rather than areas in the space, as was the case with sector agents used in previous approaches. Due to our graph structure, we find that there are far more control elements in the link agent approach than in the sector agent approach. We identify a tradeoff; link agents give finer control, but the coordination problem for the sector agents is easier because there are fewer sector agents. This indicates that we can improve performance out of a more distributed link-based setup if we address the challenges of multiagent coordination. However, the UAV traffic management domain presents a uniquely difficult coordination problem; each agent's action can affect the perceived value of every other agent's actions. This means that there is an excessive amount of noise in the system, as another agent's action can have a lot of impact on the reward an agent receives. We reduce the amount of multiagent noise by reducing the number of agents that are capable of learning. We identify that some agents have more ability to influence traffic based on the topology and traffic profile of the graph. This metric we call impactfulness. We use this metric to improve the learning by removing less impactful agents from the learning process, making a more stationary system in which the impactful agents can learn. The contributions of this work are to: - Introduce a cost-based traffic management approach that is platform-agnostic and fast to implement. - Develop a multiagent approach to setting costs in this traffic management system that is adaptive to traffic conditions and learns long-term effects of management decisions. - Create an abstraction of UAV traffic that captures key physical attributes, creating a fast and flexible simulation method. - Quantify agent contributions to system performance by experimenting with single agent learning, single agent exclusion, and a sliding number of agents learning in the system. Title: Adaptive Multiagent Traffic Management for Autonomous Robotic Systems Author: Rebhuhn, Carrie There is growing commercial interest in the use of unmanned aerial vehicles (UAVs) in urban environments, specifically for package delivery applications. However, the size, complexity and sheer numbers of expected UAVs makes conventional air traffic management that relies on human air traffic controllers infeasible. To enable UAVs to safely and efficiently operate in congested environments, it is essential to develop autonomous UAV management strategies. We introduce a dynamic hierarchical traffic control model that reacts to traffic conditions instantaneously to reduce congestion in the airspace. An obstacle-filled airspace lends itself to a modelling as a graph structure similar to a road network. We introduce controller agents, which set costs across the airspace. These agents control traffic similarly to adaptive metering lights in highway traffic. UAVs then plan their paths based on the costs (e.g. conflicts, or delays) they see for traversing particular parts of the airspace. This provides us a decentralized method for reducing traffic in an airspace Our hierarchical structure allows us to separate the traffic reduction problem from the individual robot navigation problem. Each robot does not explicitly coordinate with others in the airspace. Instead, robots execute their own individual internal cost-based planner to travel between locations. We then use neuro-evolution to provide incentives to these cost-based planners to reduce traffic in the environment. Traffic quality can be expressed in several different ways. We first evaluate traffic our traffic reduction policies in terms of `conflicts', which characterizes situations where an aircraft comes too close to another for safety in a physical space. We then examine traffic in terms of the amount of `delay' that all agents incur, which assumes that there is a structure to ensure only a safe number of UAVs occupy the same area. Finally, we look at the total travel time that a UAV can expect to take from the moment it enters the airspace until the time it gets to its destination. To facilitate an exploration of the UTM problem without waiting for a full simulation of UAVS running with A* , we develop an abstraction of the UTM domain that preserves the core UTM problem. We then investigate performance under differing levels of traffic, a well as two different agent structures. Our results show similar performance for both agent definitions, with delay reduction of up to 68% in high traffic cases. With a fast version of the UTM problem, we explore the effect of redefining the control structure such that links, or edges of the UTM graph, set costs individually. This shifts the control paradigm toward controlling directional travel rather than areas in the space, as was the case with sector agents used in previous approaches. Due to our graph structure, we find that there are far more control elements in the link agent approach than in the sector agent approach. We identify a tradeoff; link agents give finer control, but the coordination problem for the sector agents is easier because there are fewer sector agents. This indicates that we can improve performance out of a more distributed link-based setup if we address the challenges of multiagent coordination. However, the UAV traffic management domain presents a uniquely difficult coordination problem; each agent's action can affect the perceived value of every other agent's actions. This means that there is an excessive amount of noise in the system, as another agent's action can have a lot of impact on the reward an agent receives. We reduce the amount of multiagent noise by reducing the number of agents that are capable of learning. We identify that some agents have more ability to influence traffic based on the topology and traffic profile of the graph. This metric we call impactfulness. We use this metric to improve the learning by removing less impactful agents from the learning process, making a more stationary system in which the impactful agents can learn. The contributions of this work are to: - Introduce a cost-based traffic management approach that is platform-agnostic and fast to implement. - Develop a multiagent approach to setting costs in this traffic management system that is adaptive to traffic conditions and learns long-term effects of management decisions. - Create an abstraction of UAV traffic that captures key physical attributes, creating a fast and flexible simulation method. - Quantify agent contributions to system performance by experimenting with single agent learning, single agent exclusion, and a sliding number of agents learning in the system. Close

• 2268. [Article] Chemical element profiles by instrumental neutron activation analysis : in, part 1, two species of wheat bunt spores, Tilletia caries (DC) Tul. and Tilletia controversa Kühn; part 2, representative sediment and basalt samples taken from a DSDP 678 m core, site 525A, Leg 74, Walvis Ridge

  Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental ...

  Citation × Citation Citation Abstract Copy Title: Chemical element profiles by instrumental neutron activation analysis : in, part 1, two species of wheat bunt spores, Tilletia caries (DC) Tul. and Tilletia controversa Kühn; part 2, representative sediment and basalt samples taken from a DSDP 678 m core, site 525A, Leg 74, Walvis Ridge Author: Liu, Yun-gang Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental neutron activation analysis in 37 TS spore samples, and 31 DS spore samples. Aluminum was chosen as a soil contamination indicator to correct for soil contamination. The plot of the concentrations of the ith element [X[subscript i]] versus Al, yielded the biological concentrations of [X.[subscript i]]. The results show that the biological concentrations of Sc, V, La, and Sm are insignificantly small and that their contents in the spores are essentially all derived from soil dust contamination. For Na and Fe, considerable fractions, 0.15 and 0.60, respectively, of their total concentrations are derived from soil contamination. For other elements, the soil contamination contributions are relatively small compared to their biological concentrations. The "student" t-test was used for comparisons of the geometric means of the element concentrations between the TS and DS spore series. The differences between the mean values of Cl, K, Ca, Mn, Zn, and Br for the TS and CS series are not totally due to random errors within the 95% confidence level. The differences for K and Cl between the TS and DS series are large and outside the ±10- limits; therefore, the concentrations of these two elements can be used as reliable criteria for distinguishing these two species. Also, Br may be useful as a diagnostic trace element due to the significant difference between the Br geometric means of the TS and DS spores. Part 2 Forty sediment and four basement basalt samples, taken from a 678 m core drilled by the DSDP (Deep Sea Drilling Project) at Site 525A, Leg 74 (June 10-15, 1980), as well as sixteen selected basalt samples around the south Atlantic Ocean were subjected to instrumental neutron activation analysis. Thirty-two major, minor, and trace elements were determined. The core from the Wavlis Ridge site (2467 m) consisted of 574.6 m of sediment and 103.5 m of basalt. The downcore element concentration profiles and regression analyses show that the rare earth elements (REE) are present in significant amounts in both the carbonate and non-carbonate phases in sediments; Sr is concentrated in the carbonate phase; most of the other elements determined exist mainly in the non-carbonate (mostly clay) phase. The calculated partition coefficients of the REEs between the carbonate phase and the free REE ion concentrations in sea water were high and increased with decreasing REE ionic radii or increasing atomic number from 3.9x10⁶ for La to 15x10⁶ for Lu. Using the partition coefficients of the REEs in the carbonate and non-carbonate (clay) phases, the REE concentrations in Atlantic sea water were calculated, and the results indicate that the lanthanide concentrations have not been changed significantly in south Atlantic sea water over the past 70 m.y.. The Ce anomaly observed in >95% carbonate sediments is related to the Ce⁺³ concentration in sea water; therefore, the Ce anomaly is a redox (reducing-oxidizing) indicator of sea water. (Essentially, >99.99% of soluble Ce in sea water is present as Ce⁺³.) The REE patterns show no Ce depletion in mollusc shell segments from the late Campanian, and a slight Ce depletion in carbonate phases from the late Paleocene sediments. From early Eocene on, the REE patterns in the carbonate phase show a marked Ce depletion, the same as is observed in carbonates from the late Pleistocene to early Holocene (about 0.3 m.y. ago). The abrupt and striking change in the Ce depletion indicates that sea water was anoxic over the Walvis Ridge during the late Campanian. As the gap between northeast South America (northeast Brazil) and west central Africa (near the southwest corner of the upper half of Africa, e.g., near Liberia) widened and the Walvis Ridge subsided between the late Campanian and late Paleocene, sea water flow between the north Atlantic and south Atlantic oceans increased steadily, and gradually flushed out the anoxic water layer over the Walvis Ridge, thereby achieving oxidation conditions at about 54 m.y. ago, that are similar to present day sea water redox conditions: in the world oceans. The chemical compositions of the basement rocks of the core corresponds to alkalic basalts, not MA-Crean Ridge basalts (MORBs). Only a few basement rocks had been recovered from other Walvis Ridge sites. The results add more evidence which supports the hypothesis that the Wavlis Ridge was formed by a series of volcanoes moving over a "hot spot" near the Mid-Atlantic Ridge. These volcanoes migrated eastward as the South American and African continents drifted away. Most of the basalt samples taken from the southeast Brazilian continental margin also are not similar to MORE. From the bulk chemical composition and the REE pattern, one 112 m.y. old basalt has been identified as an early-stage MORB. To date, this is the oldest oceanic tholeiite recovered from the south Atlantic. This direct evidence indicates that the continental split between South America and Africa commenced ≥112 m.y. ago, and is consistent with the suggestion that the rift between the two continents began about 125 m.y. ago. Title: Chemical element profiles by instrumental neutron activation analysis : in, part 1, two species of wheat bunt spores, Tilletia caries (DC) Tul. and Tilletia controversa Kühn; part 2, representative sediment and basalt samples taken from a DSDP 678 m core, site 525A, Leg 74, Walvis Ridge Author: Liu, Yun-gang Part 1 The concentration of seventeen elements in two species of fungus which cause wheat bunt disease, Tilletia caries (DC.)Tul. (TS) and Tilletia controversa Kiihn (DS), were determined by instrumental neutron activation analysis in 37 TS spore samples, and 31 DS spore samples. Aluminum was chosen as a soil contamination indicator to correct for soil contamination. The plot of the concentrations of the ith element [X[subscript i]] versus Al, yielded the biological concentrations of [X.[subscript i]]. The results show that the biological concentrations of Sc, V, La, and Sm are insignificantly small and that their contents in the spores are essentially all derived from soil dust contamination. For Na and Fe, considerable fractions, 0.15 and 0.60, respectively, of their total concentrations are derived from soil contamination. For other elements, the soil contamination contributions are relatively small compared to their biological concentrations. The "student" t-test was used for comparisons of the geometric means of the element concentrations between the TS and DS spore series. The differences between the mean values of Cl, K, Ca, Mn, Zn, and Br for the TS and CS series are not totally due to random errors within the 95% confidence level. The differences for K and Cl between the TS and DS series are large and outside the ±10- limits; therefore, the concentrations of these two elements can be used as reliable criteria for distinguishing these two species. Also, Br may be useful as a diagnostic trace element due to the significant difference between the Br geometric means of the TS and DS spores. Part 2 Forty sediment and four basement basalt samples, taken from a 678 m core drilled by the DSDP (Deep Sea Drilling Project) at Site 525A, Leg 74 (June 10-15, 1980), as well as sixteen selected basalt samples around the south Atlantic Ocean were subjected to instrumental neutron activation analysis. Thirty-two major, minor, and trace elements were determined. The core from the Wavlis Ridge site (2467 m) consisted of 574.6 m of sediment and 103.5 m of basalt. The downcore element concentration profiles and regression analyses show that the rare earth elements (REE) are present in significant amounts in both the carbonate and non-carbonate phases in sediments; Sr is concentrated in the carbonate phase; most of the other elements determined exist mainly in the non-carbonate (mostly clay) phase. The calculated partition coefficients of the REEs between the carbonate phase and the free REE ion concentrations in sea water were high and increased with decreasing REE ionic radii or increasing atomic number from 3.9x10⁶ for La to 15x10⁶ for Lu. Using the partition coefficients of the REEs in the carbonate and non-carbonate (clay) phases, the REE concentrations in Atlantic sea water were calculated, and the results indicate that the lanthanide concentrations have not been changed significantly in south Atlantic sea water over the past 70 m.y.. The Ce anomaly observed in >95% carbonate sediments is related to the Ce⁺³ concentration in sea water; therefore, the Ce anomaly is a redox (reducing-oxidizing) indicator of sea water. (Essentially, >99.99% of soluble Ce in sea water is present as Ce⁺³.) The REE patterns show no Ce depletion in mollusc shell segments from the late Campanian, and a slight Ce depletion in carbonate phases from the late Paleocene sediments. From early Eocene on, the REE patterns in the carbonate phase show a marked Ce depletion, the same as is observed in carbonates from the late Pleistocene to early Holocene (about 0.3 m.y. ago). The abrupt and striking change in the Ce depletion indicates that sea water was anoxic over the Walvis Ridge during the late Campanian. As the gap between northeast South America (northeast Brazil) and west central Africa (near the southwest corner of the upper half of Africa, e.g., near Liberia) widened and the Walvis Ridge subsided between the late Campanian and late Paleocene, sea water flow between the north Atlantic and south Atlantic oceans increased steadily, and gradually flushed out the anoxic water layer over the Walvis Ridge, thereby achieving oxidation conditions at about 54 m.y. ago, that are similar to present day sea water redox conditions: in the world oceans. The chemical compositions of the basement rocks of the core corresponds to alkalic basalts, not MA-Crean Ridge basalts (MORBs). Only a few basement rocks had been recovered from other Walvis Ridge sites. The results add more evidence which supports the hypothesis that the Wavlis Ridge was formed by a series of volcanoes moving over a "hot spot" near the Mid-Atlantic Ridge. These volcanoes migrated eastward as the South American and African continents drifted away. Most of the basalt samples taken from the southeast Brazilian continental margin also are not similar to MORE. From the bulk chemical composition and the REE pattern, one 112 m.y. old basalt has been identified as an early-stage MORB. To date, this is the oldest oceanic tholeiite recovered from the south Atlantic. This direct evidence indicates that the continental split between South America and Africa commenced ≥112 m.y. ago, and is consistent with the suggestion that the rift between the two continents began about 125 m.y. ago. Close

• 2269. [Article] Linking greater sage-grouse habitat use and suitability across spatiotemporal scales in central Oregon

  Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by ...

  Citation × Citation Citation Abstract Copy Title: Linking greater sage-grouse habitat use and suitability across spatiotemporal scales in central Oregon Author: Freese, Mark T. Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by birds. However, little work has evaluated vegetation attributes important for Greater Sage-grouse at a landscape-scale or identified landscape attributes that influence habitat use patterns. Habitat use patterns by Greater Sage-grouse are complex and can occur across relatively large heterogeneous landscapes. This creates a major challenge for managers to interpret and predict habitat use patterns as well as to evaluate habitat suitability and prioritize habitats that are in need of ecological restoration. The goals of this research were to evaluate plot-level habitat characteristics found to be important in sustaining Greater Sage-grouse populations at a landscape-level and to identify landscape-level attributes associated with bird occurrence. Specific questions this research addressed were: 1) what is the variation in vegetation composition and structure at the plot versus landscape-level, 2) how does topography influence the distribution of vegetation composition and structure, and 3) what attributes at the landscape-level are most closely associated with Greater Sage-grouse habitat use? To address these questions we selected a 31,416 ha area in central Oregon surrounding a Greater Sage-grouse lek with a population that has been relatively stable since 1987. In February 2006, 50 Greater Sage-grouse were trapped, radio collared, and then tracked for two consecutive years. Four-hundred eighty bird UTM (Universal Transverse Mercator) coordinate location points were recorded for the entire population of birds during the duration of this study. Each collared Greater Sage-grouse was located on average every 15 ± 0.56 (mean ± SE) days, ranging from 1 to 154 days. Vegetation for the entire study area was mapped by cover types, which were defined by the dominant shrub species. When shrubs were not present in the plant community, cover types were separated by other surface characteristics such as bare ground, water, meadow, etc. A total of 23 cover types were delineated. Cover types were mapped using 0.5-m NAIP (National Agricultural Imagery Program) imagery. In addition to cover type, a set of biophysical predictor variables were created for the entire study area in a GIS (Geographic Information System) to evaluate the association with Greater Sage-grouse location points. These variables included elevation, slope, aspect, curvature, solar radiation, ruggedness index, northing, easting, and distance from roads, leks, and mesic habitats. A stratified random sample with cover types serving as the stratum was used to select random locations for sampling plot-level habitat variables. A total of 352 plots were sampled from 18 cover types across the study area with a minimum of 15 plots per cover type. Vegetation measurements collected were similar to those reported in the habitat guidelines developed by Connelly et al. (2000) and the Bureau of Land Management et al. (2000). Measurements included vegetation cover, height, and density of forbs recognized as important Greater Sage-grouse food species. Plot elevation, slope, aspect, curvature and landscape position were also recorded. Summary statistics were used to describe means and ranges within and between cover types. A combination of multiple linear regression and analysis of variance (ANOVA) were used to evaluate the effects of topographic attributes on the distribution of vegetation composition and structure. To address the third question, maximum entropy software was used to develop models that predict Greater Sage-grouse seasonal habitat use, generate maps from those models, and describe the shapes of the response curves as it relates Greater Sage-grouse habitat preference to individual landscape predictor variables. Total shrub canopy cover across all cover types averaged 19.4%, ranging from 11.6 to 27.7%. Big (mountain and Wyoming) and low sagebrush canopy cover commonly varied between 2.6 and 16 fold within cover types. Deep-rooted perennial tussock grass cover averaged across all upland plots, was 26.7%, ranging from less than 1% to over 50%. Vegetation cover, Greater Sage-grouse food forb density, and sagebrush and grass height were significantly (P < 0.05) correlated with topographic attributes. Cover for the different plant life forms and food forb density increased with elevation. Cover for most of the herbaceous life forms was also greater on north than south aspects. Compared to Connelly et al. (2000) and the BLM et al. (2000) habitat guidelines, < 1% of the study area satisfied breeding and nesting guideline criteria, while < 31% satisfied the brood-rearing guideline criteria. Although most of the study area did not meet habitat recommendations presented in the guidelines, patches imbedded throughout the study area did and most areas satisfied many but not all of the guideline requirements. These results suggests that evaluating only mean values of community structure, both within and among cover types across the study area, limited the ability to fully identify patch variability and landscape heterogeneity as it relates to habitat suitability across large areas. Maximum entropy results suggest Greater Sage-grouse habitat use during the breeding season increases near leks and within cover types of low sagebrush and low sagebrush/mountain big sagebrush complexes. Preferred summer habitat includes areas relatively high in elevation, distances that are close to leks, and within or a close proximity to habitats that harbor succulent vegetation through much of the summer. With Greater Sage-grouse utilizing resources within expansive landscapes, understanding the attributes that can be applied at a landscape-scale that attract disproportionate levels of habitat use can help managers predict where birds are likely to occur across the landscape. With the ability to discriminate between areas that Greater Sage-grouse are likely to use or avoid, managers can allocate limited resources to more effectively create, manipulate, and administer habitat conservation efforts where bird use is predicted and prioritize areas across the landscape in need of ecological restoration. Title: Linking greater sage-grouse habitat use and suitability across spatiotemporal scales in central Oregon Author: Freese, Mark T. Greater Sage-grouse (Centrocercus urophasianus) habitat research has historically focused on fine-scale (0.007 - 0.032 ha) vegetation structure and composition immediately surrounding sites selected by birds. However, little work has evaluated vegetation attributes important for Greater Sage-grouse at a landscape-scale or identified landscape attributes that influence habitat use patterns. Habitat use patterns by Greater Sage-grouse are complex and can occur across relatively large heterogeneous landscapes. This creates a major challenge for managers to interpret and predict habitat use patterns as well as to evaluate habitat suitability and prioritize habitats that are in need of ecological restoration. The goals of this research were to evaluate plot-level habitat characteristics found to be important in sustaining Greater Sage-grouse populations at a landscape-level and to identify landscape-level attributes associated with bird occurrence. Specific questions this research addressed were: 1) what is the variation in vegetation composition and structure at the plot versus landscape-level, 2) how does topography influence the distribution of vegetation composition and structure, and 3) what attributes at the landscape-level are most closely associated with Greater Sage-grouse habitat use? To address these questions we selected a 31,416 ha area in central Oregon surrounding a Greater Sage-grouse lek with a population that has been relatively stable since 1987. In February 2006, 50 Greater Sage-grouse were trapped, radio collared, and then tracked for two consecutive years. Four-hundred eighty bird UTM (Universal Transverse Mercator) coordinate location points were recorded for the entire population of birds during the duration of this study. Each collared Greater Sage-grouse was located on average every 15 ± 0.56 (mean ± SE) days, ranging from 1 to 154 days. Vegetation for the entire study area was mapped by cover types, which were defined by the dominant shrub species. When shrubs were not present in the plant community, cover types were separated by other surface characteristics such as bare ground, water, meadow, etc. A total of 23 cover types were delineated. Cover types were mapped using 0.5-m NAIP (National Agricultural Imagery Program) imagery. In addition to cover type, a set of biophysical predictor variables were created for the entire study area in a GIS (Geographic Information System) to evaluate the association with Greater Sage-grouse location points. These variables included elevation, slope, aspect, curvature, solar radiation, ruggedness index, northing, easting, and distance from roads, leks, and mesic habitats. A stratified random sample with cover types serving as the stratum was used to select random locations for sampling plot-level habitat variables. A total of 352 plots were sampled from 18 cover types across the study area with a minimum of 15 plots per cover type. Vegetation measurements collected were similar to those reported in the habitat guidelines developed by Connelly et al. (2000) and the Bureau of Land Management et al. (2000). Measurements included vegetation cover, height, and density of forbs recognized as important Greater Sage-grouse food species. Plot elevation, slope, aspect, curvature and landscape position were also recorded. Summary statistics were used to describe means and ranges within and between cover types. A combination of multiple linear regression and analysis of variance (ANOVA) were used to evaluate the effects of topographic attributes on the distribution of vegetation composition and structure. To address the third question, maximum entropy software was used to develop models that predict Greater Sage-grouse seasonal habitat use, generate maps from those models, and describe the shapes of the response curves as it relates Greater Sage-grouse habitat preference to individual landscape predictor variables. Total shrub canopy cover across all cover types averaged 19.4%, ranging from 11.6 to 27.7%. Big (mountain and Wyoming) and low sagebrush canopy cover commonly varied between 2.6 and 16 fold within cover types. Deep-rooted perennial tussock grass cover averaged across all upland plots, was 26.7%, ranging from less than 1% to over 50%. Vegetation cover, Greater Sage-grouse food forb density, and sagebrush and grass height were significantly (P < 0.05) correlated with topographic attributes. Cover for the different plant life forms and food forb density increased with elevation. Cover for most of the herbaceous life forms was also greater on north than south aspects. Compared to Connelly et al. (2000) and the BLM et al. (2000) habitat guidelines, < 1% of the study area satisfied breeding and nesting guideline criteria, while < 31% satisfied the brood-rearing guideline criteria. Although most of the study area did not meet habitat recommendations presented in the guidelines, patches imbedded throughout the study area did and most areas satisfied many but not all of the guideline requirements. These results suggests that evaluating only mean values of community structure, both within and among cover types across the study area, limited the ability to fully identify patch variability and landscape heterogeneity as it relates to habitat suitability across large areas. Maximum entropy results suggest Greater Sage-grouse habitat use during the breeding season increases near leks and within cover types of low sagebrush and low sagebrush/mountain big sagebrush complexes. Preferred summer habitat includes areas relatively high in elevation, distances that are close to leks, and within or a close proximity to habitats that harbor succulent vegetation through much of the summer. With Greater Sage-grouse utilizing resources within expansive landscapes, understanding the attributes that can be applied at a landscape-scale that attract disproportionate levels of habitat use can help managers predict where birds are likely to occur across the landscape. With the ability to discriminate between areas that Greater Sage-grouse are likely to use or avoid, managers can allocate limited resources to more effectively create, manipulate, and administer habitat conservation efforts where bird use is predicted and prioritize areas across the landscape in need of ecological restoration. Close

• 2270. [Article] Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations

  Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased ...

  Citation × Citation Citation Abstract Copy Title: Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations Author: Piacenza, Susan E. H. Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased 5.7% year⁻¹ since 1973, but wide fluctuations in census counts of nesting females make recovery diagnosis difficult. For effective management planning, it is critical to have the best information possible on vital rates, and to determine the best tools and practices for incorporating vital rate information, particularly variability, into population models to assess population size and status. Process and observation errors, compounded by late maturity, obscure the relationship between trends on the nesting beach and the entire population. Using sea turtle nesting beach surveys as a population index for assessment is problematic, yet often pragmatic because this is the only population index that is easily accessible. It is advantageous to use a modelling approach that estimates interannual variability in life history traits, accounts for uncertainty from individual-level variability, and allows for population dynamics to emerge from individual behaviors. To this end, I analyzed a long-term data set of marked green sea turtles to determine the degree of temporal variability in key life history traits. From this analysis, I built an agent-based model (ABM) to form the basis of a new assessment tool -- Monitoring Strategy Evaluation. In Chapter 2, I evaluated annual changes in demographic indicators (DIs) of 3,677 nesting green turtles from a 38-year tagging program in the Hawaiian Islands to determine if key life history traits are changing over time and in response to nester density. I used linear mixed models and multistate open robust design models to estimate several DIs and correlated them with nesting female counts. Mean nester carapace length and breeding probability were highly variable over time, suggesting shifts in age structure that could be due to recruitment. The top-ranked model predicted constant female survival over time. A significant positive relationship between the nesting population and breeding probability was evident, and breeding probability shows promise as an indicator of population recovery. This work contributes to a growing set of studies evaluating sea turtle demography for temporal variability and is the first for Hawaiian green turtles. In Chapter 3, I develop the Green Sea Turtle Agent-Based Model (GSTABM) to evaluate how recovery processes differ across disturbance types. The GSTABM incorporates individually variable age-at-maturity, clutch frequency and clutch size, annually variable breeding probability, environmental stochasticity and density dependence in hatchling production. The GSTABM simulates the process of population impact and recovery and the monitoring process, with observation error, on the nesting beach. The GSTABM captures the emergent patterns of interannual nesting variation, nester recruitment, and realistic population growth rates. Changes in survival rates of the nearshore age-stage classes directly affected adult and nester abundance, population growth rate and nester recruitment more than any of the other input parameters. In simulating 100 years of recovery, experimentally disturbed populations began to increase but did not fully return to pre-disturbance levels in adult and nester abundance, population growth or nester recruitment. In simulations with different levels of monitoring effort, adult abundance was poorly estimated, was influenced by population trajectory and disturbance type, and showed marginal improvements in accuracy with increased detection probability. Estimating recruitment showed improvements with increasing detection levels. In the GSTABM, variability in the nesting beach does not mirror variability in adult abundance. The GSTABM is an important tool to determine relationships with monitoring, population assessment, and the underlying biological processes driving changes in the population, and especially, changes on the nesting beach. In Chapter 4, I develop a new simulation-based tool: Monitoring Strategy Evaluation (MoSE) to determine which data source yields the most useful information for population assessments. The MoSE has three main components: the simulated "true" operating, observation, and estimation models. To explore this first use of MoSE, I apply different treatments of disturbance, sampling, and detection to the virtual "true" population, and then sample the nests or nesters, with observation error, to test if the observation "data" accurately diagnose population status indicators. Based on the observed data, I estimated adult abundance, nester recruitment, and population trend and compare them to the known values. I tested the accuracy of the estimated abundance when annually varying inputs of breeding probability, detection and clutch frequency were used instead of constants. I also explored the improvement of trend accuracy with increased study duration. Disturbance type and severity can have important and persistent effects on the accuracy of population assessments drawn from monitoring rookeries. Accuracy in abundance estimates may be most improved by avoiding clutch frequency bias in sampling and including annually varying inputs in the estimation model. Accuracy of nester recruitment may be most improved by increasing detection level and avoiding age-bias in sampling. The accuracy of estimating population trend is most influenced by the underlying population trajectory, disturbance type and disturbance severity. At least 10 years of monitoring data are necessary to accurately estimate population trend, and longer if juvenile age classes were disturbed and trend estimates occur during the recovery phase. The MoSE is an important tool for sea turtle biologists and conservation managers and allows biologists to make informed decisions regarding the best monitoring strategies to employ for sea turtles. This modeling framework is designed to provide an evaluation of monitoring program effectiveness to assist in planning future programs for sea turtles. Altogether, my research suggests certain life history traits of green sea turtles have important temporal variation that should be accounted for in population models, understanding the relationships between nesting and the total population is essential, and basing population assessments from nesting beach data alone is likely to result in incorrect or biased estimates of status indicators. The quantitative tools employed here can be applied to other sea turtle populations and will improve monitoring, and result in better estimates of current population trends and enhance conservation for all species of sea turtles. Title: Quantitative Tools for Monitoring Strategy Evaluation and Assessment of Sea Turtle Populations Author: Piacenza, Susan E. H. Green sea turtles, Chelonia mydas, have endangered and threatened populations globally, but several populations show signs of population recovery. In Hawaii, nesting female green turtles have increased 5.7% year⁻¹ since 1973, but wide fluctuations in census counts of nesting females make recovery diagnosis difficult. For effective management planning, it is critical to have the best information possible on vital rates, and to determine the best tools and practices for incorporating vital rate information, particularly variability, into population models to assess population size and status. Process and observation errors, compounded by late maturity, obscure the relationship between trends on the nesting beach and the entire population. Using sea turtle nesting beach surveys as a population index for assessment is problematic, yet often pragmatic because this is the only population index that is easily accessible. It is advantageous to use a modelling approach that estimates interannual variability in life history traits, accounts for uncertainty from individual-level variability, and allows for population dynamics to emerge from individual behaviors. To this end, I analyzed a long-term data set of marked green sea turtles to determine the degree of temporal variability in key life history traits. From this analysis, I built an agent-based model (ABM) to form the basis of a new assessment tool -- Monitoring Strategy Evaluation. In Chapter 2, I evaluated annual changes in demographic indicators (DIs) of 3,677 nesting green turtles from a 38-year tagging program in the Hawaiian Islands to determine if key life history traits are changing over time and in response to nester density. I used linear mixed models and multistate open robust design models to estimate several DIs and correlated them with nesting female counts. Mean nester carapace length and breeding probability were highly variable over time, suggesting shifts in age structure that could be due to recruitment. The top-ranked model predicted constant female survival over time. A significant positive relationship between the nesting population and breeding probability was evident, and breeding probability shows promise as an indicator of population recovery. This work contributes to a growing set of studies evaluating sea turtle demography for temporal variability and is the first for Hawaiian green turtles. In Chapter 3, I develop the Green Sea Turtle Agent-Based Model (GSTABM) to evaluate how recovery processes differ across disturbance types. The GSTABM incorporates individually variable age-at-maturity, clutch frequency and clutch size, annually variable breeding probability, environmental stochasticity and density dependence in hatchling production. The GSTABM simulates the process of population impact and recovery and the monitoring process, with observation error, on the nesting beach. The GSTABM captures the emergent patterns of interannual nesting variation, nester recruitment, and realistic population growth rates. Changes in survival rates of the nearshore age-stage classes directly affected adult and nester abundance, population growth rate and nester recruitment more than any of the other input parameters. In simulating 100 years of recovery, experimentally disturbed populations began to increase but did not fully return to pre-disturbance levels in adult and nester abundance, population growth or nester recruitment. In simulations with different levels of monitoring effort, adult abundance was poorly estimated, was influenced by population trajectory and disturbance type, and showed marginal improvements in accuracy with increased detection probability. Estimating recruitment showed improvements with increasing detection levels. In the GSTABM, variability in the nesting beach does not mirror variability in adult abundance. The GSTABM is an important tool to determine relationships with monitoring, population assessment, and the underlying biological processes driving changes in the population, and especially, changes on the nesting beach. In Chapter 4, I develop a new simulation-based tool: Monitoring Strategy Evaluation (MoSE) to determine which data source yields the most useful information for population assessments. The MoSE has three main components: the simulated "true" operating, observation, and estimation models. To explore this first use of MoSE, I apply different treatments of disturbance, sampling, and detection to the virtual "true" population, and then sample the nests or nesters, with observation error, to test if the observation "data" accurately diagnose population status indicators. Based on the observed data, I estimated adult abundance, nester recruitment, and population trend and compare them to the known values. I tested the accuracy of the estimated abundance when annually varying inputs of breeding probability, detection and clutch frequency were used instead of constants. I also explored the improvement of trend accuracy with increased study duration. Disturbance type and severity can have important and persistent effects on the accuracy of population assessments drawn from monitoring rookeries. Accuracy in abundance estimates may be most improved by avoiding clutch frequency bias in sampling and including annually varying inputs in the estimation model. Accuracy of nester recruitment may be most improved by increasing detection level and avoiding age-bias in sampling. The accuracy of estimating population trend is most influenced by the underlying population trajectory, disturbance type and disturbance severity. At least 10 years of monitoring data are necessary to accurately estimate population trend, and longer if juvenile age classes were disturbed and trend estimates occur during the recovery phase. The MoSE is an important tool for sea turtle biologists and conservation managers and allows biologists to make informed decisions regarding the best monitoring strategies to employ for sea turtles. This modeling framework is designed to provide an evaluation of monitoring program effectiveness to assist in planning future programs for sea turtles. Altogether, my research suggests certain life history traits of green sea turtles have important temporal variation that should be accounted for in population models, understanding the relationships between nesting and the total population is essential, and basing population assessments from nesting beach data alone is likely to result in incorrect or biased estimates of status indicators. The quantitative tools employed here can be applied to other sea turtle populations and will improve monitoring, and result in better estimates of current population trends and enhance conservation for all species of sea turtles. Close