A new and fundamentally different regional geomorphology paradigm in which massive south- and southeast-oriented meltwater floods flowed across the entire Missouri River drainage basin is tested by interpreting detail...A new and fundamentally different regional geomorphology paradigm in which massive south- and southeast-oriented meltwater floods flowed across the entire Missouri River drainage basin is tested by interpreting detailed topographic maps of the Montana upper Sun River drainage basin region by trying to explain origins of previously unexplained or poorly explained erosional landforms located upstream from Sun River Canyon (which cuts across Montana’s north-to-south oriented Sawtooth Range). Mountain passes, through valleys, and other drainage divide low points along what are today high mountain ridges, including the North American east-west continental divide, are interpreted to be evidence of drainage routes that once crossed the region. These drainage divide crossings suggest that prior to erosion of present-day upper Sun River drainage basin valleys, massive floods moved in south directions across what are today the north-oriented Middle and South Fork Flathead River drainage basins into today’s upper Sun River drainage basin area and carved a complex of diverging and converging channels into what was probably a low relief surface now represented by the crests of the region’s highest mountain ridges. Further, the map evidence shows how a diverging complex of south- and southeast-oriented upstream Sun River drainage basin flood flow channels changed flow direction to cross the Sawtooth Range in a northeast direction before converging on the Montana plains at a location downstream from Sun River Canyon. The observed upper Sun River drainage basin area topographic map evidence is consistent with the new geomorphology paradigm predictions, in which massive south-oriented meltwater floods flowing across the rising rim of a continental ice sheet created deep “hole” (created by deep ice sheet erosion and ice sheet weight caused crustal warping) are diverted to flow in northeast and north directions into and across deep “hole” space being opened up by ice sheet melting.展开更多
Jewel beetles pose significant threats to forestry,and effective traps are needed to monitor and manage them.Green traps often catch more beetles,but purple traps catch a greater proportion of females.Understanding th...Jewel beetles pose significant threats to forestry,and effective traps are needed to monitor and manage them.Green traps often catch more beetles,but purple traps catch a greater proportion of females.Understanding the function and mechanism of this behavior can provide a rationale for trap optimization.Jewel beetles possess UV-,blue-,green-,and red-sensitive photoreceptors,and perceive color differently from humans.Jewel beetle photoreceptor signals were calculated for tree leaf and tree bark stimuli,representing feeding and oviposition sites of adult jewel beetles respectively.Artificial neural networks(ANNs)were trained to discriminate those stimuli using beetle photoreceptor signals,providing in silico models of the neural processing that might have evolved to drive behavior.ANNs using blue-,green-,and red-sensitive photoreceptor inputs could classify these stimuli with very high accuracy(>99%).ANNs processed photoreceptor signals in an opponent fashion:increasing green-sensitive photoreceptor signals promoted leaf classifications,while increasing blue-and red-sensitive photoreceptor signals promoted bark classifications.Trained ANNs were fed photoreceptor signals calculated for traps,wherein they always classified green traps as leaves,but often classified purple traps as bark,indicating that these traps share salient features with different classes of tree stimuli from a beetle's eye view.A metric representing the photoreceptor opponent mechanism implicated by ANNs then explained catches of emerald ash borer,Agrilus planipennis,at differently colored traps from a previous field study.This analysis provides a hypothesized behavioral mechanism that can now guide the rational selection and improvement of jewel beetle traps.展开更多
文摘A new and fundamentally different regional geomorphology paradigm in which massive south- and southeast-oriented meltwater floods flowed across the entire Missouri River drainage basin is tested by interpreting detailed topographic maps of the Montana upper Sun River drainage basin region by trying to explain origins of previously unexplained or poorly explained erosional landforms located upstream from Sun River Canyon (which cuts across Montana’s north-to-south oriented Sawtooth Range). Mountain passes, through valleys, and other drainage divide low points along what are today high mountain ridges, including the North American east-west continental divide, are interpreted to be evidence of drainage routes that once crossed the region. These drainage divide crossings suggest that prior to erosion of present-day upper Sun River drainage basin valleys, massive floods moved in south directions across what are today the north-oriented Middle and South Fork Flathead River drainage basins into today’s upper Sun River drainage basin area and carved a complex of diverging and converging channels into what was probably a low relief surface now represented by the crests of the region’s highest mountain ridges. Further, the map evidence shows how a diverging complex of south- and southeast-oriented upstream Sun River drainage basin flood flow channels changed flow direction to cross the Sawtooth Range in a northeast direction before converging on the Montana plains at a location downstream from Sun River Canyon. The observed upper Sun River drainage basin area topographic map evidence is consistent with the new geomorphology paradigm predictions, in which massive south-oriented meltwater floods flowing across the rising rim of a continental ice sheet created deep “hole” (created by deep ice sheet erosion and ice sheet weight caused crustal warping) are diverted to flow in northeast and north directions into and across deep “hole” space being opened up by ice sheet melting.
基金funded by the European Commission(H2020-MSCA-RISE-2019,grant number:873178).
文摘Jewel beetles pose significant threats to forestry,and effective traps are needed to monitor and manage them.Green traps often catch more beetles,but purple traps catch a greater proportion of females.Understanding the function and mechanism of this behavior can provide a rationale for trap optimization.Jewel beetles possess UV-,blue-,green-,and red-sensitive photoreceptors,and perceive color differently from humans.Jewel beetle photoreceptor signals were calculated for tree leaf and tree bark stimuli,representing feeding and oviposition sites of adult jewel beetles respectively.Artificial neural networks(ANNs)were trained to discriminate those stimuli using beetle photoreceptor signals,providing in silico models of the neural processing that might have evolved to drive behavior.ANNs using blue-,green-,and red-sensitive photoreceptor inputs could classify these stimuli with very high accuracy(>99%).ANNs processed photoreceptor signals in an opponent fashion:increasing green-sensitive photoreceptor signals promoted leaf classifications,while increasing blue-and red-sensitive photoreceptor signals promoted bark classifications.Trained ANNs were fed photoreceptor signals calculated for traps,wherein they always classified green traps as leaves,but often classified purple traps as bark,indicating that these traps share salient features with different classes of tree stimuli from a beetle's eye view.A metric representing the photoreceptor opponent mechanism implicated by ANNs then explained catches of emerald ash borer,Agrilus planipennis,at differently colored traps from a previous field study.This analysis provides a hypothesized behavioral mechanism that can now guide the rational selection and improvement of jewel beetle traps.
