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• 691. [Article] Precipitation characteristics for landslide hazard assessment for the central Oregon Coast Range

  Precipitation data from 1988-1995 for 13 rain gauges of the Department of Forest Engineering rain gauge network, and a longer precipitation record, 1976-1995, at Mapleton were analyzed. The objectives ...

  Citation × Citation Citation Abstract Copy Title: Precipitation characteristics for landslide hazard assessment for the central Oregon Coast Range Author: Surfleet, Christopher G. Precipitation data from 1988-1995 for 13 rain gauges of the Department of Forest Engineering rain gauge network, and a longer precipitation record, 1976-1995, at Mapleton were analyzed. The objectives were to assess the spatial and temporal distribution of precipitation intensity and antecedent precipitation, and understand the role of these characteristics for triggering debris slides from headwalls in the central Oregon Coast Range. Frequency distribution curves and recurrence intervals using a partial-duration series were calculated for the maximum 5-minute, 30 minute, 1 hour, 2 hour, 6 hour precipitation durations and antecedent precipitation index (API) for the rain gauge network and the maximum 1 hour and 2 hour precipitation durations for Mapleton. Isohyet lines showing selected 2-year precipitation intensities and API were used to characterize the spatial distribution of precipitation intensity and API across the central Oregon Coast Range. The effect of elevation on this spatial distribution was investigated. An attempt to quantify the occurrence of high intensity precipitation occurring with high antecedent precipitation, which is hypothesized to trigger debris slides, was done by testing if the highest precipitation intensities (greater than a 1 -year recurrence interval) occurred during the storms with the highest API. API and precipitation intensity were tested for correlation to discern if a particular precipitation duration could be used to predict API, thus make it possible to use a precipitation intensity based threshold to assess the general hazard of landslides. Precipitation intensities associated with selected recurrence intervals vary considerably over the study area. Precipitation values for selected durations and recurrence intervals could vary as much as 50% or larger for selected rain gauge locations. Precipitation intensities are higher in the central portion of the study area, centered around the ridges of the Siuslaw River watershed, with decreasing intensity toward the northern and southern boundaries possibly due to topographic influences. Higher API values are found more frequent where the high precipitation intensity spatial trends exists. Relationships between short duration precipitation intensities with elevation, and API with elevation, within the rain gauge network could not be determined. No single precipitation intensity, including total storm precipitation, showed a strong positive correlation with high API for the entire rain gauge network. It appears that any attempts to predict the precipitation characteristics which trigger headwall failure by a precipitation intensity threshold in the central Oregon Coast Range is not possible. Attempts to assess the risk of headwall failure by high API may be possible. High precipitation intensities occurred with high antecedent precipitation conditions and they occur at the highest antecedent precipitation conditions. Title: Precipitation characteristics for landslide hazard assessment for the central Oregon Coast Range Author: Surfleet, Christopher G. Precipitation data from 1988-1995 for 13 rain gauges of the Department of Forest Engineering rain gauge network, and a longer precipitation record, 1976-1995, at Mapleton were analyzed. The objectives were to assess the spatial and temporal distribution of precipitation intensity and antecedent precipitation, and understand the role of these characteristics for triggering debris slides from headwalls in the central Oregon Coast Range. Frequency distribution curves and recurrence intervals using a partial-duration series were calculated for the maximum 5-minute, 30 minute, 1 hour, 2 hour, 6 hour precipitation durations and antecedent precipitation index (API) for the rain gauge network and the maximum 1 hour and 2 hour precipitation durations for Mapleton. Isohyet lines showing selected 2-year precipitation intensities and API were used to characterize the spatial distribution of precipitation intensity and API across the central Oregon Coast Range. The effect of elevation on this spatial distribution was investigated. An attempt to quantify the occurrence of high intensity precipitation occurring with high antecedent precipitation, which is hypothesized to trigger debris slides, was done by testing if the highest precipitation intensities (greater than a 1 -year recurrence interval) occurred during the storms with the highest API. API and precipitation intensity were tested for correlation to discern if a particular precipitation duration could be used to predict API, thus make it possible to use a precipitation intensity based threshold to assess the general hazard of landslides. Precipitation intensities associated with selected recurrence intervals vary considerably over the study area. Precipitation values for selected durations and recurrence intervals could vary as much as 50% or larger for selected rain gauge locations. Precipitation intensities are higher in the central portion of the study area, centered around the ridges of the Siuslaw River watershed, with decreasing intensity toward the northern and southern boundaries possibly due to topographic influences. Higher API values are found more frequent where the high precipitation intensity spatial trends exists. Relationships between short duration precipitation intensities with elevation, and API with elevation, within the rain gauge network could not be determined. No single precipitation intensity, including total storm precipitation, showed a strong positive correlation with high API for the entire rain gauge network. It appears that any attempts to predict the precipitation characteristics which trigger headwall failure by a precipitation intensity threshold in the central Oregon Coast Range is not possible. Attempts to assess the risk of headwall failure by high API may be possible. High precipitation intensities occurred with high antecedent precipitation conditions and they occur at the highest antecedent precipitation conditions. Close

• 692. [Article] Intelligence, creativity and sex-role preference among preschool-aged children

  This study explored the relationship between sex, age, intelligence, creativity and sex-role preference among preschool-aged children. Thirty-nine Caucasian children, 18 boys and 21 girls, ranging in ages ...

  Citation × Citation Citation Abstract Copy Title: Intelligence, creativity and sex-role preference among preschool-aged children Author: Frost, Nancy Sanger This study explored the relationship between sex, age, intelligence, creativity and sex-role preference among preschool-aged children. Thirty-nine Caucasian children, 18 boys and 21 girls, ranging in ages from three years-five months to five years-two months acted as subjects for this study, All subjects came from intact families, predominantly of the middle- and upper-socioeconomic classes as determined by Hollingshead's Two Factor Index of Social Position. The instruments used to collect the data for this study included: Brown's It Scale for Children to assess the subjects' sex-role preferences; Dunn's Peabody Picture Vocabulary Test to estimate the subjects' intelligence; and Ward's Alternative Uses and Pattern Meanings Tests to assess the subjects' creativity, Four null hypotheses were generated and the analysis of variance approach was used to test these hypotheses, F-values were generated for tests of the main effects of sex, age, intelligence and creativity and their interaction effects. The 01 level of significance was used as the criterion for statistical significance. Findings obtained are summarized below. There was a significant difference between the sex-role preference scores of boys and girls (F = 11. 7457, p < 0. 01) with boys having significantly higher own sex-role preference scores than girls. This finding was in support of theoretical positions that point to the cultural deterininants of sex-role learning. A study of the mean values associated with the sex interaction effect comparisons, while not statistically significant, revealed tendencies in the data which further substantiated the above finding. There was no significant difference between the sex-role preference scores of older and younger subjects. However, a study of the mean values associated with the main effect of age and its interactions, although not statistically significant, indicated a tendency for older subjects to have higher own sex-role preference scores than younger subjects. This finding is in support of the social learning theory of sex-role development. There was no significant difference between the sex-role preference scores of very-high and average-high intelligence subjects. A study of the mean values associated with the main effect of intelligence and its interaction effects, however, provided information which tended to support the cognitive- developmental theory of sex role learning that there will be a differential relationship between intelligence and sex-role learning among boys and girls. Boys of very-high intelligence tended to have higher own sex-role preference scores than boys of average-high intelligence at both the younger and older age groupings. Such a difference, however, tended to be greater among boys in the older age grouping thanin the younger age grouping. Among girls, findings indicated a tendency for girls of very-high intelligence to have slightly higher though minimally, own sex-role preference scores than girls of average-high intelligence at the younger age grouping while at the older age grouping girls of veryhigh intelligence had lower own sex-role preference scores than girls of average-high intelligence. Furthermore, while older girls of average-high intelligence tended to have much higher own sex-role preference scores than younger girls of average-high intelligence, the difference in sex-role preference scores of very-Thigh intelligence older and younger girls was. minimal. There was no significant difference between the sex-role preference scores of creative and less creative subjects. A study of the mean values associated with the main effect of creativity and its interaction effects tended to be inconsistent with or contradict findings that would be expected on the basis of previous theory and research, Previous theoretical positions have indicated that creativity would be positively related to opposite-sex role learning among individuals. In this study, creative and less creative subjects as determined by the Alt e r nate Uses Test showed no apparent differences in their own sex-role preferences. Furthermore, creative and less creative subjects, as determined by the Pattern Meanings Test, revealed creative subjects to have slightly higher own sex-role preference scores than less creative subjects. In addition, both creative boys and girls, as determined by the Alternate Uses Test, had slightly higher, own sex-role preference scores than less creative boys and girls. When the creativity of subjects was determined by the Pattern Meanings Test, however, creative boys tended to have higher own sex-role preference scores than less creative boys, while creative girls had slightly lower own sex-role preference scores than less creative girls. This difference among girls, however, was minimal. Finally, further analysis of the data regarding socioeconomic class differences among subjects in the present study indicated that subjects in the highest socioeconomic class (Class I) and lower socioeconomic classes (Classes III and IV) tended to have higher own sexrole preference scores than subjects between these classes (Class II). It should be emphasized that due to the statistical non-significance of many of these findings and the variety of limitations encountered in this study, extreme caution must be exercised in accepting these results. Title: Intelligence, creativity and sex-role preference among preschool-aged children Author: Frost, Nancy Sanger This study explored the relationship between sex, age, intelligence, creativity and sex-role preference among preschool-aged children. Thirty-nine Caucasian children, 18 boys and 21 girls, ranging in ages from three years-five months to five years-two months acted as subjects for this study, All subjects came from intact families, predominantly of the middle- and upper-socioeconomic classes as determined by Hollingshead's Two Factor Index of Social Position. The instruments used to collect the data for this study included: Brown's It Scale for Children to assess the subjects' sex-role preferences; Dunn's Peabody Picture Vocabulary Test to estimate the subjects' intelligence; and Ward's Alternative Uses and Pattern Meanings Tests to assess the subjects' creativity, Four null hypotheses were generated and the analysis of variance approach was used to test these hypotheses, F-values were generated for tests of the main effects of sex, age, intelligence and creativity and their interaction effects. The 01 level of significance was used as the criterion for statistical significance. Findings obtained are summarized below. There was a significant difference between the sex-role preference scores of boys and girls (F = 11. 7457, p < 0. 01) with boys having significantly higher own sex-role preference scores than girls. This finding was in support of theoretical positions that point to the cultural deterininants of sex-role learning. A study of the mean values associated with the sex interaction effect comparisons, while not statistically significant, revealed tendencies in the data which further substantiated the above finding. There was no significant difference between the sex-role preference scores of older and younger subjects. However, a study of the mean values associated with the main effect of age and its interactions, although not statistically significant, indicated a tendency for older subjects to have higher own sex-role preference scores than younger subjects. This finding is in support of the social learning theory of sex-role development. There was no significant difference between the sex-role preference scores of very-high and average-high intelligence subjects. A study of the mean values associated with the main effect of intelligence and its interaction effects, however, provided information which tended to support the cognitive- developmental theory of sex role learning that there will be a differential relationship between intelligence and sex-role learning among boys and girls. Boys of very-high intelligence tended to have higher own sex-role preference scores than boys of average-high intelligence at both the younger and older age groupings. Such a difference, however, tended to be greater among boys in the older age grouping thanin the younger age grouping. Among girls, findings indicated a tendency for girls of very-high intelligence to have slightly higher though minimally, own sex-role preference scores than girls of average-high intelligence at the younger age grouping while at the older age grouping girls of veryhigh intelligence had lower own sex-role preference scores than girls of average-high intelligence. Furthermore, while older girls of average-high intelligence tended to have much higher own sex-role preference scores than younger girls of average-high intelligence, the difference in sex-role preference scores of very-Thigh intelligence older and younger girls was. minimal. There was no significant difference between the sex-role preference scores of creative and less creative subjects. A study of the mean values associated with the main effect of creativity and its interaction effects tended to be inconsistent with or contradict findings that would be expected on the basis of previous theory and research, Previous theoretical positions have indicated that creativity would be positively related to opposite-sex role learning among individuals. In this study, creative and less creative subjects as determined by the Alt e r nate Uses Test showed no apparent differences in their own sex-role preferences. Furthermore, creative and less creative subjects, as determined by the Pattern Meanings Test, revealed creative subjects to have slightly higher own sex-role preference scores than less creative subjects. In addition, both creative boys and girls, as determined by the Alternate Uses Test, had slightly higher, own sex-role preference scores than less creative boys and girls. When the creativity of subjects was determined by the Pattern Meanings Test, however, creative boys tended to have higher own sex-role preference scores than less creative boys, while creative girls had slightly lower own sex-role preference scores than less creative girls. This difference among girls, however, was minimal. Finally, further analysis of the data regarding socioeconomic class differences among subjects in the present study indicated that subjects in the highest socioeconomic class (Class I) and lower socioeconomic classes (Classes III and IV) tended to have higher own sexrole preference scores than subjects between these classes (Class II). It should be emphasized that due to the statistical non-significance of many of these findings and the variety of limitations encountered in this study, extreme caution must be exercised in accepting these results. Close

• 693. [Article] The geochemical evolution of the Aucanquilcha Volcanic Cluster : prolonged magmatism and its crustal consequences

  The interaction of magma with continental crust at convergent margins is fundamental to understanding if and how continents grow. Isotopic and elemental data constrain the progressive stages of development ...

  Citation × Citation Citation Abstract Copy Title: The geochemical evolution of the Aucanquilcha Volcanic Cluster : prolonged magmatism and its crustal consequences Author: Walker, Barry Alan The interaction of magma with continental crust at convergent margins is fundamental to understanding if and how continents grow. Isotopic and elemental data constrain the progressive stages of development of the magmatic underpinnings of the long-lived Aucanquilcha Volcanic Cluster (AVC), situated atop the thick continental crust of the central Andes in northern Chile. Whole rock data are used in conjunction with mineral compositions to infer processes that gave rise to eleven million years of intermediate, dominantly dacite, arc volcanism. A pulse of volcanic activity at the AVC between ~5 and 2 Ma is bracketed by more sluggish rates. We document chemical changes in the lavas that accompany this eruptive evolution. Trace element data suggest that crystal fractionation and magma mixing were the dominant mechanisms generating the diversity observed in the AVC whole rock data. Fractionation was dominant during early and waning stages of magmatism, and magma mixing was an important process during the high flux period. Peak thermal maturity of the AVC underpinnings coincided with the high magma flux and likely promoted open system processes during this time. Mineral compositions from zircon, amphibole, pyroxene, and Fe-Ti oxides confirm the importance of material recycling in the production of evolved AVC rocks. Various geothermometers were employed to calculate the pre-eruptive conditions of AVC magma using mineral compositions. Pressure estimates from amphibole and two-pyroxene barometry indicate crystallization depths of 1 – 5 kb and 4 – 6 kb, respectively. Temperature estimates from zircon, Fe-Ti oxides, amphiboles, and pyroxenes indicate temperatures ranging from ~700°C to 1100°C. Zircon temperatures are always the lowest (700°C - 950°C), and pyroxene temperatures are always the highest (1000°C - 1100°C), with Fe-Ti oxide and amphiboles temperatures falling in between. U-Pb ages from zircons and thermometry from individual samples evidence the thermal maturation and consolidation of the underpinnings below the AVC, presumably culminating in a large, crystal-rich mush zone where magmas were trapped and processed. It is in these middle to upper crustal zones where magmatic diversity is attenuated and giant, relatively homogeneous batholiths are formed. Isotopes of AVC lavas are similar to values observed from other central Andes volcanic centers. Lead isotopes are consistent with the AVC's location within a Pb isotope transition zone between the Antofalla and Arequipa basement terranes. Oxygen and Sr isotopic ratios are high and Nd isotopic ratios low with respect to a depleted mantle. Through time, ⁸⁷Sr/⁸⁶Sr values of AVC lavas progressively increase from lows of ~0.70507 to ~0.70579 (upper values of 0.70526 to 0.70680), and εNd values decrease from highs of -1.0 to -4.6 (lows of -1.6 to -7.3). Similarly, O isotopes (δ¹⁸O) show a slight increase in base level through time from lows of 6.5‰ to 7.0‰ (highs of 6.75‰ – 7.5‰). Dy/Yb and Sm/Yb ratios also increased systematically from highs of 2.11 to 3.45, and 2.76 to 6.67, respectively. Despite the temporal isotopic variation, there is little isotopic variation with indices of fractionation, suggesting this signal is the consequence of deep magmatic processing, here attributed to an expanding zone of melting, assimilation, storage, and homogenization (MASH) of mantle-derived magma in the deep crust. Upward expansion brought the MASH zone into contact with rocks that were increasingly evolved with respect to Sr and Nd isotopes, explaining the isotopic shifts. Downward expansion of the MASH zone enhanced garnet stability during basalt fractionation, explaining the increased Dy/Yb and Sm/Yb ratios. Mass balance calculations involving Sr, Nd, and O isotope modeling are consistent with a crustal component making up 10 - 30% of AVC lavas, implying that although the history of central Andean magmatism is replete with large scale crustal recycling, the current phase is largely a crust formation event. Title: The geochemical evolution of the Aucanquilcha Volcanic Cluster : prolonged magmatism and its crustal consequences Author: Walker, Barry Alan The interaction of magma with continental crust at convergent margins is fundamental to understanding if and how continents grow. Isotopic and elemental data constrain the progressive stages of development of the magmatic underpinnings of the long-lived Aucanquilcha Volcanic Cluster (AVC), situated atop the thick continental crust of the central Andes in northern Chile. Whole rock data are used in conjunction with mineral compositions to infer processes that gave rise to eleven million years of intermediate, dominantly dacite, arc volcanism. A pulse of volcanic activity at the AVC between ~5 and 2 Ma is bracketed by more sluggish rates. We document chemical changes in the lavas that accompany this eruptive evolution. Trace element data suggest that crystal fractionation and magma mixing were the dominant mechanisms generating the diversity observed in the AVC whole rock data. Fractionation was dominant during early and waning stages of magmatism, and magma mixing was an important process during the high flux period. Peak thermal maturity of the AVC underpinnings coincided with the high magma flux and likely promoted open system processes during this time. Mineral compositions from zircon, amphibole, pyroxene, and Fe-Ti oxides confirm the importance of material recycling in the production of evolved AVC rocks. Various geothermometers were employed to calculate the pre-eruptive conditions of AVC magma using mineral compositions. Pressure estimates from amphibole and two-pyroxene barometry indicate crystallization depths of 1 – 5 kb and 4 – 6 kb, respectively. Temperature estimates from zircon, Fe-Ti oxides, amphiboles, and pyroxenes indicate temperatures ranging from ~700°C to 1100°C. Zircon temperatures are always the lowest (700°C - 950°C), and pyroxene temperatures are always the highest (1000°C - 1100°C), with Fe-Ti oxide and amphiboles temperatures falling in between. U-Pb ages from zircons and thermometry from individual samples evidence the thermal maturation and consolidation of the underpinnings below the AVC, presumably culminating in a large, crystal-rich mush zone where magmas were trapped and processed. It is in these middle to upper crustal zones where magmatic diversity is attenuated and giant, relatively homogeneous batholiths are formed. Isotopes of AVC lavas are similar to values observed from other central Andes volcanic centers. Lead isotopes are consistent with the AVC's location within a Pb isotope transition zone between the Antofalla and Arequipa basement terranes. Oxygen and Sr isotopic ratios are high and Nd isotopic ratios low with respect to a depleted mantle. Through time, ⁸⁷Sr/⁸⁶Sr values of AVC lavas progressively increase from lows of ~0.70507 to ~0.70579 (upper values of 0.70526 to 0.70680), and εNd values decrease from highs of -1.0 to -4.6 (lows of -1.6 to -7.3). Similarly, O isotopes (δ¹⁸O) show a slight increase in base level through time from lows of 6.5‰ to 7.0‰ (highs of 6.75‰ – 7.5‰). Dy/Yb and Sm/Yb ratios also increased systematically from highs of 2.11 to 3.45, and 2.76 to 6.67, respectively. Despite the temporal isotopic variation, there is little isotopic variation with indices of fractionation, suggesting this signal is the consequence of deep magmatic processing, here attributed to an expanding zone of melting, assimilation, storage, and homogenization (MASH) of mantle-derived magma in the deep crust. Upward expansion brought the MASH zone into contact with rocks that were increasingly evolved with respect to Sr and Nd isotopes, explaining the isotopic shifts. Downward expansion of the MASH zone enhanced garnet stability during basalt fractionation, explaining the increased Dy/Yb and Sm/Yb ratios. Mass balance calculations involving Sr, Nd, and O isotope modeling are consistent with a crustal component making up 10 - 30% of AVC lavas, implying that although the history of central Andean magmatism is replete with large scale crustal recycling, the current phase is largely a crust formation event. Close

• 694. [Article] The Future of Agriculture and Society in Iowa: Four Scenarios

  Iowa is a leader in crop and livestock production, but its high productivity has had concomitant negative environmental and societal impacts and large requirements for fossil-fuel-derived inputs. Maintaining ...

  Citation × Citation Citation Abstract Copy Title: The Future of Agriculture and Society in Iowa: Four Scenarios Author: Jarchow, Meghann E., Larsen, G. L. Drake, Costanza, Robert, Zdorkowski, Gretchen, Gailans, Stefans R., Ohde, Nicholaus, Dietzel, Ranae, Kaplan, Sara, Neal, Jeri, Petrehn, Mae Rose, Gunther, Theodore, D’Adamo, Stephanie N., McCann, Nicholas, Larson, Andrew, Damery, Phillip, Gross, Lee, Merriman, Marc, Kubiszewski, Ida, Post, Julian, Sheradin, Meghan, Liebman, Matt Year: 2012 Iowa is a leader in crop and livestock production, but its high productivity has had concomitant negative environmental and societal impacts and large requirements for fossil-fuel-derived inputs. Maintaining agricultural productivity, economic prosperity and environmental integrity will become ever more challenging as the global demand for agricultural products increases and the resources needed become increasingly limited. Here we present four scenarios for Iowa in 2100, based on combinations of differing goals for the economy and differing energy availability. In scenarios focused on high material throughput, environmental degradation and social unrest will increase. In scenarios with a focus on human and environmental welfare, environmental damage will be ameliorated and societal happiness will increase. Movement towards a society focused on human and environmental welfare will require changes in the goals of the economy, whereas no major changes will be needed to maintain focus on high throughput. When energy sources are readily available and inexpensive, the goals of the economy will be more easily met, whereas energy limitations will restrict the options available to agriculture and society. Our scenarios can be used as tools to inform people about choices that must be made to reach more desirable futures for Iowa and similar agricultural regions Title: The Future of Agriculture and Society in Iowa: Four Scenarios Author: Jarchow, Meghann E., Larsen, G. L. Drake, Costanza, Robert, Zdorkowski, Gretchen, Gailans, Stefans R., Ohde, Nicholaus, Dietzel, Ranae, Kaplan, Sara, Neal, Jeri, Petrehn, Mae Rose, Gunther, Theodore, D’Adamo, Stephanie N., McCann, Nicholas, Larson, Andrew, Damery, Phillip, Gross, Lee, Merriman, Marc, Kubiszewski, Ida, Post, Julian, Sheradin, Meghan, Liebman, Matt Year: 2012 Iowa is a leader in crop and livestock production, but its high productivity has had concomitant negative environmental and societal impacts and large requirements for fossil-fuel-derived inputs. Maintaining agricultural productivity, economic prosperity and environmental integrity will become ever more challenging as the global demand for agricultural products increases and the resources needed become increasingly limited. Here we present four scenarios for Iowa in 2100, based on combinations of differing goals for the economy and differing energy availability. In scenarios focused on high material throughput, environmental degradation and social unrest will increase. In scenarios with a focus on human and environmental welfare, environmental damage will be ameliorated and societal happiness will increase. Movement towards a society focused on human and environmental welfare will require changes in the goals of the economy, whereas no major changes will be needed to maintain focus on high throughput. When energy sources are readily available and inexpensive, the goals of the economy will be more easily met, whereas energy limitations will restrict the options available to agriculture and society. Our scenarios can be used as tools to inform people about choices that must be made to reach more desirable futures for Iowa and similar agricultural regions Close

• 695. [Article] Geogenic Cadmium Pollution and Potential Health Risks, With Emphasis on Black Shale

  Cadmium (Cd) is a non-essential trace element that is toxic to humans. Previous studies of Cd in the environment have primarily focused on pollution resulted from anthropogenic sources, but little is known ...

  Citation × Citation Citation Abstract Copy Title: Geogenic Cadmium Pollution and Potential Health Risks, With Emphasis on Black Shale Author: Liu, Yizhang, Xiao, Tangfu, Perkins, Robert, Zhu, Jianming, Zhu, Zhengjie, Xiong, Yan, Ning, Zengping Year: 2016 Cadmium (Cd) is a non-essential trace element that is toxic to humans. Previous studies of Cd in the environment have primarily focused on pollution resulted from anthropogenic sources, but little is known on naturally occurring sources of Cd. This paper aims to review the geochemical distribution of geogenic Cd and associated environmental risk. The source, accumulation, mobility, transportation, and health risk of Cd are discussed in a geo-environmental perspective, with an emphasis on black shale soils. Cadmium generally occurs in sulfides in black shale, and is easily released when exposed to oxygen and water. Leaching of these rocks tends to elevate Cd concentrations in aquatic systems, and may pose the potential to produce acid rock drainage (ARD) as well. Weathering of Cd-rich rocks also elevates soil Cd concentrations, and influence the geochemical species of Cd. Crops grown in these soils tend to accumulate higher Cd and threaten the food safety. Local inhabitant exposed to high geogenic Cd via food chains may experience Cd-related health risk. High Cd concentrations are observed in urine, and renal damage is also detected in Cd naturally enriched area based on low molecular weight proteins in urine. Overall, the findings in literature have provided with insights for potential health risk of Cd in areas with high Cd geochemical background levels, particular for the black shale exposed areas, more attentions should be paid on the geogenic Cd pollution, and suitable strategies of remediation and geo-environmental management for geogenic Cd pollution need further research. Title: Geogenic Cadmium Pollution and Potential Health Risks, With Emphasis on Black Shale Author: Liu, Yizhang, Xiao, Tangfu, Perkins, Robert, Zhu, Jianming, Zhu, Zhengjie, Xiong, Yan, Ning, Zengping Year: 2016 Cadmium (Cd) is a non-essential trace element that is toxic to humans. Previous studies of Cd in the environment have primarily focused on pollution resulted from anthropogenic sources, but little is known on naturally occurring sources of Cd. This paper aims to review the geochemical distribution of geogenic Cd and associated environmental risk. The source, accumulation, mobility, transportation, and health risk of Cd are discussed in a geo-environmental perspective, with an emphasis on black shale soils. Cadmium generally occurs in sulfides in black shale, and is easily released when exposed to oxygen and water. Leaching of these rocks tends to elevate Cd concentrations in aquatic systems, and may pose the potential to produce acid rock drainage (ARD) as well. Weathering of Cd-rich rocks also elevates soil Cd concentrations, and influence the geochemical species of Cd. Crops grown in these soils tend to accumulate higher Cd and threaten the food safety. Local inhabitant exposed to high geogenic Cd via food chains may experience Cd-related health risk. High Cd concentrations are observed in urine, and renal damage is also detected in Cd naturally enriched area based on low molecular weight proteins in urine. Overall, the findings in literature have provided with insights for potential health risk of Cd in areas with high Cd geochemical background levels, particular for the black shale exposed areas, more attentions should be paid on the geogenic Cd pollution, and suitable strategies of remediation and geo-environmental management for geogenic Cd pollution need further research. Close

• 696. [Article] The influence on winter wheat yields of competitive weedy species

  A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. ...

  Citation × Citation Citation Abstract Copy Title: The influence on winter wheat yields of competitive weedy species Author: Albeke, William Edgar A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. The experiments were designed so that the effects of variety, nitrogen fertilization, and weed competition could be evaluated. The interactions between these factors were also studied. Ryegrass (Loolium app.) and downy brome (Bromus tectorum) were the two weed species studied. Under high winter rainfall and ryegrass competition yields of wheat were seriously impaired in both the short and tall growing wheat varieties tested. As rates of nitrogen increased yields of wheat did not increase where a medium or heavy stand of ryegrass was present. Yield of wheat was reduced under high nitrogen and high ryegrass competition. A response to 60 pounds of nitrogen per acre was noted where no ryegrass competition was present. One hundred twenty pounds of nitrogen did not increase yields appreciably, especially in the Gaines variety. In the two remaining experiments, response to nitrogen fertilization was not as prominent due to lack of moisture throughout the growing season. However, downy brome competition decreased yields at one location under all three fertility levels. At the other location a poor stand of downy brome and arid conditions accounted for the lack of competitive effects. No differences were noted in competing abilities of the tall vs. the short growing varieties. In general it was concluded that in order to get maximum response from nitrogen fertilization in wheat, weeds would have to be controlled. Title: The influence on winter wheat yields of competitive weedy species Author: Albeke, William Edgar A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. The experiments were designed so that the effects of variety, nitrogen fertilization, and weed competition could be evaluated. The interactions between these factors were also studied. Ryegrass (Loolium app.) and downy brome (Bromus tectorum) were the two weed species studied. Under high winter rainfall and ryegrass competition yields of wheat were seriously impaired in both the short and tall growing wheat varieties tested. As rates of nitrogen increased yields of wheat did not increase where a medium or heavy stand of ryegrass was present. Yield of wheat was reduced under high nitrogen and high ryegrass competition. A response to 60 pounds of nitrogen per acre was noted where no ryegrass competition was present. One hundred twenty pounds of nitrogen did not increase yields appreciably, especially in the Gaines variety. In the two remaining experiments, response to nitrogen fertilization was not as prominent due to lack of moisture throughout the growing season. However, downy brome competition decreased yields at one location under all three fertility levels. At the other location a poor stand of downy brome and arid conditions accounted for the lack of competitive effects. No differences were noted in competing abilities of the tall vs. the short growing varieties. In general it was concluded that in order to get maximum response from nitrogen fertilization in wheat, weeds would have to be controlled. Close

• 697. [Article] Effects of Preinoculation with VAM fungi isolated from different sites on plant tolerance to salinity in soils amended with sodium chloride

  The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils would alleviate salt effects on growth and productivity was tested on ...

  Citation × Citation Citation Abstract Copy Title: Effects of Preinoculation with VAM fungi isolated from different sites on plant tolerance to salinity in soils amended with sodium chloride Author: Cantrell, Isabella Cardona The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils would alleviate salt effects on growth and productivity was tested on lettuce (Lactuca sativa L.) and onion (Allium cepa L.). A secondary hypothesis was that the fungi isolated from a saline soil would be more effective than those from a nonsaline soil. VAM inocula from a high-and a low-salt soil were trap-cultured, their propagules quantified, adjusted, and added to a pasteurized growth medium in which seeds germinated and seedlings grew for a few weeks. These seedlings, once colonized by VAM fungi, were transplanted into saline soil. Seedlings were exposed to high concentrations of NaCl at the time of transplant; in this respect, our technique aimed to simulate conditions of high salinity prevalent in soils affected by NaCl. Preinoculated lettuce and onion transplants grown for 10 weeks had increased shoot biomass compared with nonVAM plants at all salinity (NaCl) levels tested. Leaves of VAM lettuce at the highest salt level were significantly greener than those of the nonVAM lettuce. NonVAM onions were stunted due to available P deficiency in the soil, but inoculation with VAM fungi alleviated P deficiency and salinity effects except at the highest salinity level; nevertheless, VAM onions were significantly larger at all salinity levels. Increasing the level of available P by weekly applications to nonVAM plants partially alleviated the salinity effects on onion growth. VAM fungi from the saline soil site were not more effective in ameliorating the reduction on plant growth caused by salt than those from the nonsaline site. Colonization of roots and length of soil hyphae produced by the test fungi decreased with increasing salt. Results indicate that preinoculation of transplants with VAM fungi can effectively alleviate deleterious effects of saline soils on crop productivity. Title: Effects of Preinoculation with VAM fungi isolated from different sites on plant tolerance to salinity in soils amended with sodium chloride Author: Cantrell, Isabella Cardona The hypothesis that inoculation of transplants with vesicular-arbuscular mycorrhizal (VAM) fungi before planting into saline soils would alleviate salt effects on growth and productivity was tested on lettuce (Lactuca sativa L.) and onion (Allium cepa L.). A secondary hypothesis was that the fungi isolated from a saline soil would be more effective than those from a nonsaline soil. VAM inocula from a high-and a low-salt soil were trap-cultured, their propagules quantified, adjusted, and added to a pasteurized growth medium in which seeds germinated and seedlings grew for a few weeks. These seedlings, once colonized by VAM fungi, were transplanted into saline soil. Seedlings were exposed to high concentrations of NaCl at the time of transplant; in this respect, our technique aimed to simulate conditions of high salinity prevalent in soils affected by NaCl. Preinoculated lettuce and onion transplants grown for 10 weeks had increased shoot biomass compared with nonVAM plants at all salinity (NaCl) levels tested. Leaves of VAM lettuce at the highest salt level were significantly greener than those of the nonVAM lettuce. NonVAM onions were stunted due to available P deficiency in the soil, but inoculation with VAM fungi alleviated P deficiency and salinity effects except at the highest salinity level; nevertheless, VAM onions were significantly larger at all salinity levels. Increasing the level of available P by weekly applications to nonVAM plants partially alleviated the salinity effects on onion growth. VAM fungi from the saline soil site were not more effective in ameliorating the reduction on plant growth caused by salt than those from the nonsaline site. Colonization of roots and length of soil hyphae produced by the test fungi decreased with increasing salt. Results indicate that preinoculation of transplants with VAM fungi can effectively alleviate deleterious effects of saline soils on crop productivity. Close

• 698. [Article] Symbiotic characteristics of Rhizobium leguminosarum bv. trifolii recovered from nodules of field-grown Trifolium subterraneum L.

  In a series of greenhouse experiments, isolates representing serotypically distinct subpopulations of Rhizobium leguminosarum bv. trifolii recovered from root nodules of field-grown subclover Trifolium ...

  Citation × Citation Citation Abstract Copy Title: Symbiotic characteristics of Rhizobium leguminosarum bv. trifolii recovered from nodules of field-grown Trifolium subterraneum L. Author: Wanjagi, Francis Ndung'u In a series of greenhouse experiments, isolates representing serotypically distinct subpopulations of Rhizobium leguminosarum bv. trifolii recovered from root nodules of field-grown subclover Trifolium subterraneum cv. "Nangeela"), were evaluated for their symbiotic effectiveness potential, their effect on regrowth potential of subclover, and for their competitive abilities to form nodules. Isolates from the nodule dominant serotypes AS6, AS6-21, and AS21 were shown to be suboptimally effective at fixing nitrogen gas (N₂) relative to RT162X95, a highly effective commercial inoculant strain. Although the majority of isolates representing the minor nodule occupying serotypes AS27, AG4, and AP17 were also shown to be of moderate effectiveness, isolates ADS14 and RW11 of serotype AS27 were equally as effective as RT162X95. Subclover regrowth was influenced by the severity of the first harvest. Plant-isolate combinations possessing superior N₂-fixing capabilities were more adversely affected by severe clipping than were the less effective combinations. Isolate 88FL3,5, a mediocre N₂-fixing member of the nodule dominant serotype AS6, was not universally more competitive at forming nodules than other isolates. Although 88FL3,5 formed more nodules than many of the other isolates when mixed in equal numbers with each of them separately, isolates ADS14 and ADS16 significantly outcompeted 88FL3,5 even though they represented a minor nodule occupying serotype, AS27. The nodule occupying successes of 88FL3,5 or ADS16 could be overcome if their respective competitor had a numerical advantage ranging between 10:1 and 25:1. Since the soil-borne population of 88FL3,5 has been shown to outnumber other subpopulations of rhizobia in the same soil by at least 10:1, it is not surprising that it can occupy the majority of nodules on field-grown plants even in the presence of more competitive types. Why the highly effective and highly competitive members of serotype AS27 are rarely recovered from nodules of field-grown Trifolium subterraneum L. is a question that merits further study. Title: Symbiotic characteristics of Rhizobium leguminosarum bv. trifolii recovered from nodules of field-grown Trifolium subterraneum L. Author: Wanjagi, Francis Ndung'u In a series of greenhouse experiments, isolates representing serotypically distinct subpopulations of Rhizobium leguminosarum bv. trifolii recovered from root nodules of field-grown subclover Trifolium subterraneum cv. "Nangeela"), were evaluated for their symbiotic effectiveness potential, their effect on regrowth potential of subclover, and for their competitive abilities to form nodules. Isolates from the nodule dominant serotypes AS6, AS6-21, and AS21 were shown to be suboptimally effective at fixing nitrogen gas (N₂) relative to RT162X95, a highly effective commercial inoculant strain. Although the majority of isolates representing the minor nodule occupying serotypes AS27, AG4, and AP17 were also shown to be of moderate effectiveness, isolates ADS14 and RW11 of serotype AS27 were equally as effective as RT162X95. Subclover regrowth was influenced by the severity of the first harvest. Plant-isolate combinations possessing superior N₂-fixing capabilities were more adversely affected by severe clipping than were the less effective combinations. Isolate 88FL3,5, a mediocre N₂-fixing member of the nodule dominant serotype AS6, was not universally more competitive at forming nodules than other isolates. Although 88FL3,5 formed more nodules than many of the other isolates when mixed in equal numbers with each of them separately, isolates ADS14 and ADS16 significantly outcompeted 88FL3,5 even though they represented a minor nodule occupying serotype, AS27. The nodule occupying successes of 88FL3,5 or ADS16 could be overcome if their respective competitor had a numerical advantage ranging between 10:1 and 25:1. Since the soil-borne population of 88FL3,5 has been shown to outnumber other subpopulations of rhizobia in the same soil by at least 10:1, it is not surprising that it can occupy the majority of nodules on field-grown plants even in the presence of more competitive types. Why the highly effective and highly competitive members of serotype AS27 are rarely recovered from nodules of field-grown Trifolium subterraneum L. is a question that merits further study. Close

• 699. [Article] The influence of various surfactant-herbicide ratios in three volumes of water on the toxicity of dalapon, paraquat, and terbacil to winter oats (Avena sativa L.)

  Several studies were conducted to determine if a more consistent predictor of phytotoxicity to winter oats could be obtained with a surfactant-herbicide ratio or a per-unit-volume concentration of surfactant, independent ...

  Citation × Citation Citation Abstract Copy Title: The influence of various surfactant-herbicide ratios in three volumes of water on the toxicity of dalapon, paraquat, and terbacil to winter oats (Avena sativa L.) Author: Migchelbrink, Kenneth John Several studies were conducted to determine if a more consistent predictor of phytotoxicity to winter oats could be obtained with a surfactant-herbicide ratio or a per-unit-volume concentration of surfactant, independent of volume. The herbicides tested were 2,2-dichloropropionic acid (dalapon), 1,1'-dimethyl-4, 4'-bipyridinium (paraquat), and 3-tert-butyl-5-chloro-6-methyluracil (terbacil) with the nonionic surfactant X-77 (80% alkylaryl polyoxyethylene glycols, free fatty acids, and isopropanol) in 25, 50, and 75 gallons of water. All plants were grown in the greenhouse with no supplemental light. Ten plants per pot constituted a replication. All pots were placed in watering trays and irrigated as needed. Neither a constant surfactant-herbicide ratio nor a per-unit-volume concentration of surfactant proved to be a consistent predictor of phytotoxicity. There was a trend of increased phytotoxicity with increasing volumes of water with paraquat and terbacil at the 1/4 lb/acre rate. With the 9 lb/acre rate of dalapon, maximum phytotoxic effects were obtained at the highest volume and the highest rate of surfactant. At the 6 lb/acre rate of dalapon, increased phytotoxic effects were exhibited with a decrease in volume and an increase in surfactant. High rates of surfactant with terbacil produced necrotic effects one day after spraying. The symptoms were similar to a contact herbicide such as paraquat. High rates of surfactant without herbicide caused phytotoxic effects. The high rates of surfactant used alone caused an orange appearance in the apical portion of the leaves. One experiment with terbacil indicated that phytotoxicity may be closely related to drying time of the spray solution on the oat leaf. Using drying time as a criterion for predicting phytotoxicity may encompass the many factors related to successful and consistent surfactant activity. Additional testing of this theory should be pursued. Title: The influence of various surfactant-herbicide ratios in three volumes of water on the toxicity of dalapon, paraquat, and terbacil to winter oats (Avena sativa L.) Author: Migchelbrink, Kenneth John Several studies were conducted to determine if a more consistent predictor of phytotoxicity to winter oats could be obtained with a surfactant-herbicide ratio or a per-unit-volume concentration of surfactant, independent of volume. The herbicides tested were 2,2-dichloropropionic acid (dalapon), 1,1'-dimethyl-4, 4'-bipyridinium (paraquat), and 3-tert-butyl-5-chloro-6-methyluracil (terbacil) with the nonionic surfactant X-77 (80% alkylaryl polyoxyethylene glycols, free fatty acids, and isopropanol) in 25, 50, and 75 gallons of water. All plants were grown in the greenhouse with no supplemental light. Ten plants per pot constituted a replication. All pots were placed in watering trays and irrigated as needed. Neither a constant surfactant-herbicide ratio nor a per-unit-volume concentration of surfactant proved to be a consistent predictor of phytotoxicity. There was a trend of increased phytotoxicity with increasing volumes of water with paraquat and terbacil at the 1/4 lb/acre rate. With the 9 lb/acre rate of dalapon, maximum phytotoxic effects were obtained at the highest volume and the highest rate of surfactant. At the 6 lb/acre rate of dalapon, increased phytotoxic effects were exhibited with a decrease in volume and an increase in surfactant. High rates of surfactant with terbacil produced necrotic effects one day after spraying. The symptoms were similar to a contact herbicide such as paraquat. High rates of surfactant without herbicide caused phytotoxic effects. The high rates of surfactant used alone caused an orange appearance in the apical portion of the leaves. One experiment with terbacil indicated that phytotoxicity may be closely related to drying time of the spray solution on the oat leaf. Using drying time as a criterion for predicting phytotoxicity may encompass the many factors related to successful and consistent surfactant activity. Additional testing of this theory should be pursued. Close

• 700. [Article] Socio-ecological vulnerability in a Tibetan village on the Lancang River, China

  This ethnographic research examines socioeconomic vulnerabilities to resettlement from a large hydropower dam and agricultural commodification in a Tibetan village in Yunnan Province, Southwest China. ...

  Citation × Citation Citation Abstract Copy Title: Socio-ecological vulnerability in a Tibetan village on the Lancang River, China Author: Galipeau, Brendan A. This ethnographic research examines socioeconomic vulnerabilities to resettlement from a large hydropower dam and agricultural commodification in a Tibetan village in Yunnan Province, Southwest China. After providing an initial background on the dynamics of the research region and hydrodevelopment on its rivers, the research framework of examining vulnerability through a lens of political ecology and local knowledge is outlined. Utilizing this framework, the socioeconomic strategies surrounding agriculture and commodified forest products within the study village are initially outlined through the use of oral histories, previous literature, and quantitative household survey data. After providing a detailed background on these income strategies, vulnerabilities to resettlement are examined through qualitative analysis of individual household interviews. This analysis shows that village households are highly reliant on the village's specific location in order to collect the resources and pursue the agriculture that they do; making them vulnerable to future resettlement. The analysis also shows that in the opinions of villagers, a good standard of living is significantly defined by their ability to pursue specific economic strategies. Next, interview results are analyzed to show how agricultural commodification and a very high reliance on one government sponsored company to purchase crops has also made the village highly vulnerable economically. The thesis concludes with reflections on future hydrodevelopment and resettlement scenarios within the village, and provides recommendations to improve local level resilience and promote better capacity to adapt to change. Title: Socio-ecological vulnerability in a Tibetan village on the Lancang River, China Author: Galipeau, Brendan A. This ethnographic research examines socioeconomic vulnerabilities to resettlement from a large hydropower dam and agricultural commodification in a Tibetan village in Yunnan Province, Southwest China. After providing an initial background on the dynamics of the research region and hydrodevelopment on its rivers, the research framework of examining vulnerability through a lens of political ecology and local knowledge is outlined. Utilizing this framework, the socioeconomic strategies surrounding agriculture and commodified forest products within the study village are initially outlined through the use of oral histories, previous literature, and quantitative household survey data. After providing a detailed background on these income strategies, vulnerabilities to resettlement are examined through qualitative analysis of individual household interviews. This analysis shows that village households are highly reliant on the village's specific location in order to collect the resources and pursue the agriculture that they do; making them vulnerable to future resettlement. The analysis also shows that in the opinions of villagers, a good standard of living is significantly defined by their ability to pursue specific economic strategies. Next, interview results are analyzed to show how agricultural commodification and a very high reliance on one government sponsored company to purchase crops has also made the village highly vulnerable economically. The thesis concludes with reflections on future hydrodevelopment and resettlement scenarios within the village, and provides recommendations to improve local level resilience and promote better capacity to adapt to change. Close