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Migrating eastern North Pacific gray whale call and blow rates estimated from acoustic recordings, infrared camera video, and visual sightings.
During the eastern North Pacific gray whale 2014-2015 southbound migration, acoustic call recordings, infrared blow detections, and visual sightings were combined to estimate cue rates, needed to convert detections into abundance. The gray whale acoustic call rate ranged from 2.3-24 calls/whale/day during the peak of the southbound migration with an average of 7.5 calls/whale/day over both the southbound and northbound migrations. The average daily calling rate increased between 30 December-13 February. With a call rate model, we estimated that 4,340 gray whales migrated south before visual observations began on 30 December, which is 2,829 more gray whales than used in the visual estimate, and would add approximately 10% to the abundance estimate. We suggest that visual observers increase their survey effort to all of December to document gray whale presence. The infrared camera blow rate averaged 49 blows/whale/hour over 5-8 January. Probability of detection of a whale blow by the infrared camera was the same at night as during the day. However, probability of detection decreased beyond 2.1 km offshore, whereas visual sightings revealed consistent whale densities up to 3 km offshore. We suggest that future infrared camera surveys use multiple cameras optimised for different ranges offshore
Mesoscopic phase statistics of diffuse ultrasound in dynamic matter
Temporal fluctuations in the phase of waves transmitted through a dynamic,
strongly scattering, mesoscopic sample are investigated using ultrasonic waves,
and compared with theoretical predictions based on circular Gaussian
statistics. The fundamental role of phase in Diffusing Acoustic Wave
Spectroscopy is revealed, and phase statistics are also shown to provide a
sensitive and accurate way to probe scatterer motions at both short and long
time scales.Comment: 4 pages, 4 figures, submitted to Physical Review Letter
Viking navigation
A comprehensive description of the navigation of the Viking spacecraft throughout their flight from Earth launch to Mars landing is given. The flight path design, actual inflight control, and postflight reconstruction are discussed in detail. The preflight analyses upon which the operational strategies and performance predictions were based are discussed. The inflight results are then discussed and compared with the preflight predictions and, finally, the results of any postflight analyses are presented
Pod Yield Comparison of Pure-Line Peanut Selections Simultaneously Developed from Georgia and Zimbabwe Breeding Programs
Crosses were made between two widely grown U.S. peanut (Arachis hypogaea L.) cultivars, ‘Florunner’ and Florigiant’, and two genotypes adapted to growing conditions on the plateau of tropical Africa, ‘Makulu Red’ and 486 GKP. F2 seed populations were equally divided between Georgia and Zimbabwe. Subsequently, pedigree selection was practised simultaneously at both locations in the early segregating generations. The highest yielding pureline selections were then interchanged, and combined yield evaluations were determined over three growing seasons at each location.
‘Florunner’, ‘Florigiant’, and the Georgia pureline selections tested at the Georgia location had significantly higher pod yields than ‘Makulu Red’, 486 GKP, and the Zimbabwe selections. Conversely, the mean yield of the Zimbabwe selections tested m Zimbabwe was significantly higher than that of the Georgia selections. Thus, the breeding environment under which selection is conducted among cross populations strongly influences the yield adaptability of selected peanut genotype
A Millimeter-Wave Galactic Plane Survey With The BICEP Polarimeter
In addition to its potential to probe the Inflationary cosmological paradigm,
millimeter-wave polarimetry is a powerful tool for studying the Milky Way
galaxy's composition and magnetic field structure. Towards this end, presented
here are Stokes I, Q, and U maps of the Galactic plane from the millimeter-wave
polarimeter BICEP covering the Galactic longitude range 260 - 340 degrees in
three atmospheric transmission windows centered on 100, 150, and 220 GHz. The
maps sample an optical depth 1 < AV < 30, and are consistent with previous
characterizations of the Galactic millimeter-wave frequency spectrum and the
large-scale magnetic field structure permeating the interstellar medium.
Polarized emission is detected over the entire region within two degrees of the
Galactic plane and indicates that the large-scale magnetic field is oriented
parallel to the plane of the Galaxy. An observed trend of decreasing
polarization fraction with increasing total intensity rules out the simplest
model of a constant Galactic magnetic field throughout the Galaxy. Including
WMAP data in the analysis, the degree-scale frequency spectrum of Galactic
polarization fraction is plotted between 23 and 220 GHz for the first time. A
generally increasing trend of polarization fraction with electromagnetic
frequency is found, which varies from 0.5%-1.5%at frequencies below 50 GHz to
2.5%-3.5%above 90 GHz. The BICEP and WMAP data are fit to a two-component
(synchrotron and dust) model showing that the higher frequency BICEP data are
necessary to tightly constrain the amplitude and spectral index of Galactic
dust. Furthermore, the dust amplitude predicted by this two-component fit is
consistent with model predictions of dust emission in the BICEP bands
Far-infrared polarimetry from the Stratospheric Observatory for Infrared Astronomy
Multi-wavelength imaging polarimetry at far-infrared wavelengths has proven
to be an excellent tool for studying the physical properties of dust, molecular
clouds, and magnetic fields in the interstellar medium. Although these
wavelengths are only observable from airborne or space-based platforms, no
first-generation instrument for the Stratospheric Observatory for Infrared
Astronomy (SOFIA) is presently designed with polarimetric capabilities. We
study several options for upgrading the High-resolution Airborne Wideband
Camera (HAWC) to a sensitive FIR polarimeter. HAWC is a 12 x 32 pixel bolometer
camera designed to cover the 53 - 215 micron spectral range in 4 colors, all at
diffraction-limited resolution (5 - 21 arcsec). Upgrade options include: (1) an
external set of optics which modulates the polarization state of the incoming
radiation before entering the cryostat window; (2) internal polarizing optics;
and (3) a replacement of the current detector array with two state-of-the-art
superconducting bolometer arrays, an upgrade of the HAWC camera as well as
polarimeter. We discuss a range of science studies which will be possible with
these upgrades including magnetic fields in star-forming regions and galaxies
and the wavelength-dependence of polarization.Comment: 12 pages, 5 figure
Organization of the gravity-sensing system in zebrafish
Motor circuits develop in sequence from those governing fast movements to those governing slow. Here we examine whether upstream sensory circuits are organized by similar principles. Using serial-section electron microscopy in larval zebrafish, we generated a complete map of the gravity-sensing (utricular) system spanning from the inner ear to the brainstem. We find that both sensory tuning and developmental sequence are organizing principles of vestibular topography. Patterned rostrocaudal innervation from hair cells to afferents creates an anatomically inferred directional tuning map in the utricular ganglion, forming segregated pathways for rostral and caudal tilt. Furthermore, the mediolateral axis of the ganglion is linked to both developmental sequence and neuronal temporal dynamics. Early-born pathways carrying phasic information preferentially excite fast escape circuits, whereas later-born pathways carrying tonic signals excite slower postural and oculomotor circuits. These results demonstrate that vestibular circuits are organized by tuning direction and dynamics, aligning them with downstream motor circuits and behaviors
Transverse confinement of ultrasound through the Anderson transition in 3D mesoglasses
We report an in-depth investigation of the Anderson localization transition
for classical waves in three dimensions (3D). Experimentally, we observe clear
signatures of Anderson localization by measuring the transverse confinement of
transmitted ultrasound through slab-shaped mesoglass samples. We compare our
experimental data with predictions of the self-consistent theory of Anderson
localization for an open medium with the same geometry as our samples. This
model describes the transverse confinement of classical waves as a function of
the localization (correlation) length, (), and is fitted to our
experimental data to quantify the transverse spreading/confinement of
ultrasound all of the way through the transition between diffusion and
localization. Hence we are able to precisely identify the location of the
mobility edges at which the Anderson transitions occur.Comment: 16 pages, 11 figure
4. The School Develops
Between 1947 and 1953, when M.P. Catherwood left the deanship to become New York’s industrial commissioner, the ILR School developed into a full fledged enterprise. These pages attempt to capture some of the excitement of this period of the school’s history, which was characterized by vigor, growth, and innovation. Includes: Alumni Recall Their Lives as Students; The Faculty Were Giants; Alice Cook: Lifelong Scholar, Consummate Teacher; Frances Perkins; Visits and Visitors; Tenth Anniversary: Reflection and Change; The Emergence of Departments at ILR; Development of International Programs and Outreach
Nuclear Bar Catalyzed Star Formation: 13^CO, C18^O and Molecular Gas Properties in the Nucleus of Maffei 2
(Abridged) We present resolution maps of CO, its isotopologues, and HCN from
in the center of Maffei 2. The J=1-0 rotational lines of 12^CO, 13^CO, C18^O
and HCN, and the J=2-1 lines of 13^CO and C18^O were observed with the OVRO and
BIMA arrays. The 2-1/1-0 line ratios of the isotopologues constrain the bulk of
the molecular gas to originate in low excitation, subthermal gas. From LVG
modeling, we infer that the central GMCs have n(H_2) ~10^2.75 cm^-3 and T_k ~
30 K. Continuum emission at 3.4 mm, 2.7 mm and 1.4 mm was mapped to determine
the distribution and amount of HII regions and dust. Column densities derived
from C18^O and 1.4 mm dust continuum fluxes indicate the CO conversion factor
in the center of Maffei 2 is lower than Galactic by factors of ~2-4. Gas
morphology and the clear ``parallelogram'' in the Position-Velocity diagram
shows that molecular gas orbits within the potential of a nuclear (~220 pc)
bar. The nuclear bar is distinct from the bar that governs the large scale
morphology of Maffei 2. Giant molecular clouds in the nucleus are nonspherical
and have large linewidths. Dense gas and star formation are concentrated at the
sites of the x_1-x_2 orbit intersections of the nuclear bar, suggesting that
the starburst is dynamically triggered.Comment: 50 pages, 14 figures, accepted for publication in Ap
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