Joseph Fly'high Miller - Academia.edu (original) (raw)
Papers by Joseph Fly'high Miller
Dynamic climatic oscillations of the Pleistocene dramatically changed the distributions of high l... more Dynamic climatic oscillations of the Pleistocene dramatically changed the distributions of high latitude species. Molecular investigations of a variety of organisms show that processes of postglacial colonization of boreal regions were more complex than initially thought. Phylogeographical and coalescent analyses were conducted on partial sequences of the cytochrome b gene (600 bp) from 64 individuals of Clethrionomys gapperi from North Carolina, Pennsylvania, Minnesota, Idaho, Washington, British Columbia, Northwest Territories, and Alaska to test hypotheses relating to Pleistocene refugia and postglacial colonization routes. Three divergent clades (east, west, central) were identified with highest net divergence ( d A = 5.2%) between the eastern and western clades. Populations from the recently deglaciated higher latitudes of Canada and Alaska are closely related to lower latitude populations of the central clade ( d A = 1.2%) suggesting recent expansion from this midwestern region. No representatives from the east or west clade were found at latitudes higher than 50°°°° N, indicating that postglacial colonization occurred through a midcontinental route. The high latitude population from the Northwest Territories exhibited demographic patterns and genetic diversity consistent with a stable noncolonizing population. This population is found near the Mackenzie range, where the two continental ice sheets were believed to have coalesced. Molecular variation observed in this population may be the result of leading edge population diversifying in the continental corridor or may reflect the signal of a high latitude refugial population.
Atmospheric Research, 2001
We describe a new type of lidar instrument, Wide-Angle Imaging Lidar (WAIL), designed to study an... more We describe a new type of lidar instrument, Wide-Angle Imaging Lidar (WAIL), designed to study and directly make use of multiple scattering in clouds. Providing time-resolved imagery over a 60°field of view, the new instrument captures returns at virtually all orders of scattering in a groundbased measurement. We report the first retrievals of cloud properties using this system, from measurements of a moderately opaque altostratus. Following insights from photon diffusion theory, we are able to infer the physical thickness and optical depth of the cloud layer, and, from there, obtain an estimate of the volume-averaged liquid water content. Performance of the new instrument is discussed and it is compared with other active techniques in cloud remote sensing. D
How we decide whether a course of action is worth undertaking is largely unknown. Recently, neuro... more How we decide whether a course of action is worth undertaking is largely unknown. Recently, neuroscientists have been turning to ecological approaches to address this issue, examining how animals evaluate the costs and benefits of different options. We present here evidence from rodents and monkeys that demonstrate the degree to which they take into account work and energetic requirements when deciding what responses to make. These calculations appear to be critically mediated by the anterior cingulate cortex (ACC) and mesolimbic dopamine (DA) pathways, with damage to either causing a bias towards options that are easily obtained but yield relatively smaller reward rather than alternatives that require more work but result in greater reward. The evaluation of such decisions appears to be carried out in systems independent of those involved in delay-discounting. We suggest that top-down signals from ACC to nucleus accumbens (NAc) and/or midbrain DA cells may be vital for overcoming effort-related response costs.
Dynamic climatic oscillations of the Pleistocene dramatically changed the distributions of high l... more Dynamic climatic oscillations of the Pleistocene dramatically changed the distributions of high latitude species. Molecular investigations of a variety of organisms show that processes of postglacial colonization of boreal regions were more complex than initially thought. Phylogeographical and coalescent analyses were conducted on partial sequences of the cytochrome b gene (600 bp) from 64 individuals of Clethrionomys gapperi from North Carolina, Pennsylvania, Minnesota, Idaho, Washington, British Columbia, Northwest Territories, and Alaska to test hypotheses relating to Pleistocene refugia and postglacial colonization routes. Three divergent clades (east, west, central) were identified with highest net divergence ( d A = 5.2%) between the eastern and western clades. Populations from the recently deglaciated higher latitudes of Canada and Alaska are closely related to lower latitude populations of the central clade ( d A = 1.2%) suggesting recent expansion from this midwestern region. No representatives from the east or west clade were found at latitudes higher than 50°°°° N, indicating that postglacial colonization occurred through a midcontinental route. The high latitude population from the Northwest Territories exhibited demographic patterns and genetic diversity consistent with a stable noncolonizing population. This population is found near the Mackenzie range, where the two continental ice sheets were believed to have coalesced. Molecular variation observed in this population may be the result of leading edge population diversifying in the continental corridor or may reflect the signal of a high latitude refugial population.
Atmospheric Research, 2001
We describe a new type of lidar instrument, Wide-Angle Imaging Lidar (WAIL), designed to study an... more We describe a new type of lidar instrument, Wide-Angle Imaging Lidar (WAIL), designed to study and directly make use of multiple scattering in clouds. Providing time-resolved imagery over a 60°field of view, the new instrument captures returns at virtually all orders of scattering in a groundbased measurement. We report the first retrievals of cloud properties using this system, from measurements of a moderately opaque altostratus. Following insights from photon diffusion theory, we are able to infer the physical thickness and optical depth of the cloud layer, and, from there, obtain an estimate of the volume-averaged liquid water content. Performance of the new instrument is discussed and it is compared with other active techniques in cloud remote sensing. D
How we decide whether a course of action is worth undertaking is largely unknown. Recently, neuro... more How we decide whether a course of action is worth undertaking is largely unknown. Recently, neuroscientists have been turning to ecological approaches to address this issue, examining how animals evaluate the costs and benefits of different options. We present here evidence from rodents and monkeys that demonstrate the degree to which they take into account work and energetic requirements when deciding what responses to make. These calculations appear to be critically mediated by the anterior cingulate cortex (ACC) and mesolimbic dopamine (DA) pathways, with damage to either causing a bias towards options that are easily obtained but yield relatively smaller reward rather than alternatives that require more work but result in greater reward. The evaluation of such decisions appears to be carried out in systems independent of those involved in delay-discounting. We suggest that top-down signals from ACC to nucleus accumbens (NAc) and/or midbrain DA cells may be vital for overcoming effort-related response costs.