Plasticity of Alarm-call Response Development in Belding’s Ground Squirrels ( Spermophilus beldingi , Sciuridae)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72444/1/j.1439-0310.1999.00389.x.pd

The dissociation of NO–Ar(A) from around threshold to 200 cm−1 above threshold

We report an investigation of the dissociation of A state NO–Ar at energies from 23 cm−1 below the dissociation energy to 200 cm−1 above. The NO product rotational distributions show population in states that are not accessible with the energy available for excitation from the NO ground state. This effect is observed at photon energies from below the dissociation energy up to approximately 100 cm−1 above it. Translational energy distributions, extracted from velocity map images of individual rotational levels of the NO product, reveal contributions from excitation of high energy NO–Ar X states at all the excess energies probed, although this diminishes with increasing photon energy and is quite small at 200 cm−1, the highest energy studied. These translational energy distributions show that there are contributions arising from population in vibrational levels up to the X state dissociation energy. We propose that the reason such sparsely populated levels contribute to the observed dissociation is a considerable increase in the transition moment, via the Franck–Condon factor associated with these highly excited states, which arises because of the quite different geometries in the NO–Ar X and A states. This effect is likely to arise in other systems with similarly large geometry changes

The binding energies of NO–Rg (Rg = He, Ne, Ar) determined by velocity map imaging

We report velocity map imaging measurements of the binding energies, D0, of NO–Rg (Rg = He, Ne, Ar) complexes. The X state binding energies determined are 3.0 ± 1.8, 28.6 ± 1.7, and 93.5 ± 0.9 cm−1 for NO–He, –Ne, and –Ar, respectively. These values compare reasonably well with ab initio calculations. Because the A–X transitions were unable to be observed for NO–He and NO–Ne, values for the binding energies in the A state of these complexes have not been determined. Based on our X state value and the reported A–X origin band position, the A state binding energy for NO–Ar was determined to be 50.6 ± 0.9 cm−1

Variability in Fluoroscopic X-Ray Exposure in Contemporary Cardiac Catheterization Laboratories

ObjectivesThis study sought to assess fluoroscopic exposure rates in contemporary cardiac catheterization laboratories (CCL).BackgroundIncreasing attention is being focused on X-ray exposure during diagnostic and therapeutic cardiovascular procedures.MethodsWe measured fluoroscopic exposure rates (R/min) in 41 systems using a standardized methodology (National Electrical Manufacturers Association XR21 phantom). Measurements were obtained at 2 different phantom thicknesses to simulate varying patient body habitus.ResultsFluoroscopic exposure rates under medium (median 3.0 R/min, interquartile range 1.4 R/min) and large (median 12.5 R/min, interquartile range 4.8 R/min) habitus conditions showed substantial variation. Fluoroscopic exposure was associated with simulated patient habitus, X-ray system type, vendor, and geographic region. Under medium habitus conditions, only 25% of systems operated within a zone of lower than average exposure rates and satisfactory image quality; this frequency diminished to 7% under large habitus conditions (p < 0.001).ConclusionsThere is substantial variation (4- to 6-fold) in fluoroscopic exposure rates. This variation was not consistently associated with improved image quality. In the absence of a predictable benefit of higher (or lower) than average exposure rates, CCL quality improvement programs must minimize such potentially harmful variability in X-ray exposure

A New Method for Laminar Boundary Layer Transition Visualization in Flight: Color Changes in Liquid Crystal Coatings

The visualization of laminar to turbulent boundary layer transition plays an important role in flight and wind tunnel aerodynamic testing of aircraft wing and body surfaces. Visualization can help provide a more complete understanding of both transition location as well as transition modes; without visualization, the transition process can be very difficult to understand. In the past, the most valuable transition visualization methods for fight applications included sublimating chemicals and oil flows. Each method has advantages and limitations. In particular, sublimating chemicals are impractical to use in subsonic applications much above 20,000 feet because of the greatly reduced rates of sublimation at lower temperatures (less than -4 degrees Fahrenheit). Both oil flow and sublimating chemicals have the disadvantage of providing only one good data point per flight. Thus, for many important flight conditions, transition visualization has not been readily available. This paper discusses a new method for visualizing transition in fight by the use of liquid crystals. The new method overcomes the limitations of past techniques, and provides transition visualization capability throughout almost the entire altitude and speed ranges of virtually all subsonic aircraft flight envelopes. The method also has wide applicability for supersonic transition visualization in flight and for general use in wind tunnel research over wide subsonic and supersonic speed ranges

Kin recognition by phenotype matching in female Belding's ground squirrels

Female Belding's ground squirrels (Spermophilus beldingi), that had been reared apart from each other, were observed in paired-encounter tests to determine whether exposure to nestmates' phenotypes during development had influenced their subsequent social discriminations. As a result of cross-fostering, test partners were (1) either unfamiliar sisters (reared apart) or unfamiliar, unrelated females, and were (2) either reared with each other's siblings (indirectly exposed to each other) or were not reared with each other's siblings (not indirectly exposed to each other). Regardless of relatedness, females that were indirectly exposed to each other were significantly less agonistic during tests than females not indirectly exposed to each other. This suggests that females learned something from their nestmates' phenotypes and later recalled what they had learned in order to distinguish between their nestmates' unfamiliar kin and non-kin. Furthermore, sisters that were indirectly exposed to each other were less agonistic than nonsisters that were indirectly exposed to each other. This was true even when the only kin phenotypes females had experienced during rearing were their own, which suggests that females may have compared unfamiliar phenotypes with their own, as well as those of their nestmates. Thus, the phenotypes that females encountered during rearing, both their nestmates' and their own, influenced their later social discriminations, probably by phenotype matching. Under this recognition mechanism, an individual forms a hypothetical `kin template' based on its own or its familiar relatives' phenotypes, and later compares the phenotypes of other conspecifics with the learned template.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26265/1/0000350.pd

Jamming transitions in a schematic model of suspension rheology

We study the steady-state response to applied stress in a simple scalar model of sheared colloids. Our model is based on a schematic (F2) model of the glass transition, with a memory term that depends on both stress and shear rate. For suitable parameters, we find transitions from a fluid to a nonergodic, jammed state, showing zero flow rate in an interval of applied stress. Although the jammed state is a glass, we predict that jamming transitions have an analytical structure distinct from that of the conventional mode coupling glass transition. The static jamming transition we discuss is also distinct from hydrodynamic shear thickening.Comment: 7 pages; 3 figures; improved version with added references. Accepted for publication in Europhysics Letter

An Analysis Package for Bolometer Ground Testing

ESA's Herschel Space Observatory, to be launched in 2007, will be sensitive to far infrared wavelengths beyond 60 μm. The longer wavelength interval between 200 and 670 μm will be covered by SPIRE, a combination of broad band camera and Fourier transform spectrometer. SPIRE will use exclusively spiderweb bolometers as detectors, which are manufactured and tested at JPL. We describe a data analysis package developed at the NASA Herschel Science Center at IPAC in support of the testing activity, which expects to cover 12 detector arrays with between 24 and 144 channels each. The package consists of a widget based viewer allowing immediate display and limited processing of the 193 recorded data channels in the lab and a suite of subroutines and scripts, allowing fast and flexible pipeline data reduction

Initial test results on bolometers for the Planck high frequency instrument

We summarize the fabrication, flight qualification, and dark performance of bolometers completed at the Jet Propulsion Laboratory for the High Frequency Instrument (HFI) of the joint ESA/NASA Herschel/Planck mission to be launched in 2009. The HFI is a multicolor focal plane which consists of 52 bolometers operated at 100 mK. Each bolometer is mounted to a feedhorn-filter assembly which defines one of six frequency bands centered between 100-857 GHz. Four detectors in each of five bands from 143-857 GHz are coupled to both linear polarizations and thus measure the total intensity. In addition, eight detectors in each of four bands (100, 143, 217, and 353 GHz) couple only to a single linear polarization and thus provide measurements of the Stokes parameters, Q and U, as well as the total intensity. The measured noise equivalent power (NEP) of all detectors is at or below the background limit for the telescope and time constants are a few ms, short enough to resolve point sources as the 5 to 9 arc min beams move across the sky at 1 rpm