1,678 research outputs found
Temperature inversion symmetry in the Casimir effect with an antiperiodic boundary condition
We present explicitly another example of a temperature inversion symmetry in
the Casimir effect for a nonsymmetric boundary condition. We also give an
interpretation for our result.Comment: 4 page
Implementation of the Temporary Assistance for Needy Families (TANF) on American Indian Reservations: Early Evidence from Arizona
This study is aimed at monitoring the impact of the 1996 federal welfare legislation on American Indian families with children on reservations within the state of Arizona over five years (1997-2002). Our goal is to inform the public policy debate on how to improve the social and economic opportunities for low-income families with children on reservations. This report is based on our first year (October 1, 1997-September 30,1998) of work, which focused on aspects of reform implementation and short-term and potential long-term outcomes. We analyzed secondary data from administrative sources relevant to the implementation of welfare legislation in Indian communities. In addition, we collected and analyzed primary (qualitative) data regarding welfare reform options implemented on reservations and their potential impacts. Primary data were collected from in-depth telephone interviews with service providers of 15 of the 21 reservations in Arizona. This information was substantiated by two site visits to three reservations where we conducted focus groups with current and former welfare recipients and state and tribal social service providers
Kif4 Interacts with EB1 and Stabilizes Microtubules Downstream of Rho-mDia in Migrating Fibroblasts
Selectively stabilized microtubules (MTs) form in the lamella of fibroblasts and contribute to cell migration. A Rho-mDia-EB1 pathway regulates the formation of stable MTs, yet how selective stabilization of MTs is achieved is unknown. Kinesin activity has been implicated in selective MT stabilization and a number of kinesins regulate MT dynamics both in vitro and in cells. Here, we show that the mammalian homolog of Xenopus XKLP1, Kif4, is both necessary and sufficient for the induction of selective MT stabilization in fibroblasts. Kif4 localized to the ends of stable MTs and participated in the Rho-mDia-EB1 MT stabilization pathway since Kif4 depletion blocked mDia- and EB1-induced selective MT stabilization and EB1 was necessary for Kif4 induction of stable MTs. Kif4 and EB1 interacted in cell extracts, and binding studies revealed that the tail domain of Kif4 interacted directly with the N-terminal domain of EB1. Consistent with its role in regulating formation of stable MTs in interphase cells, Kif4 knockdown inhibited migration of cells into wounded monolayers. These data identify Kif4 as a novel factor in the Rho-mDia-EB1 MT stabilization pathway and cell migration
Transient Plasma Ignition of Hydrocarbon-Air Mixtures
42nd AIAA Aerospace Sciences Meeting and Exhibit AIAA 2004-834 5 - 8 January 2004, Reno, NevadaThe article of record as published may be found at http://dx.doi.org10.2514/6.2004-834A transient plasma ignition system has been demonstrated to substantially reduce the ignition delay and detonation-to-detonation transition times for ethylene-air and propane-air mixtures under dynamic fill conditions. The effects initial conditions including equivalence ratio, a temperature range of 280K to 430K, and pressure range of 1 to 6 atm were evaluated. Ignition delays were reduced by up to a factor of 5 and the correspondingdeflagration-to-detonationtime scales were observed to decrease accordingly when compared to conventional capacitive dischargesystems. Thesubstantialreductionoftheignitiondelaytimesresultedinthegeneration of strong pressure waves which inherently steepened into shock waves quickly and in a short distance. Although direct initiation of a detonation wave was not obtained, the sub sequential use of a Shchelkin spiral was able to rapidly and reliably accelerate the combustion driven shock waves to detonations within practical distances. The efficiency and performance of the transient plasma ignition strategy will likely contribute to the development of fuel-air detonation initiators
Measurements of Anisotropy in the Cosmic Microwave Background Radiation at 0.5 Degree Angular Scales Near the Star Gamma Ursae Minoris
We present results from a four frequency observation of a 6 x 0.6 degree
strip of the sky centered near the star Gamma Ursae Minoris during the fourth
flight of the Millimeter-wave Anisotropy eXperiment (MAX). The observation was
made with a 1.4 degree peak-to-peak sinusoidal chop in all bands. The FWHM beam
sizes were 0.55 +/- 0.05 degrees at 3.5 cm-1 and 0.75 +/-0.05 degrees at 6, 9,
and 14 cm-1. During this observation significant correlated structure was
observed at 3.5, 6 and 9 cm-1 with amplitudes similar to those observed in the
GUM region during the second and third flights of MAX. The frequency spectrum
is consistent with CMB and inconsistent with thermal emission from interstellar
dust. The extrapolated amplitudes of synchrotron and free-free emission are too
small to account for the amplitude of the observed structure. If all of the
structure is attributed to CMB anisotropy with a Gaussian autocorrelation
function and a coherence angle of 25', then the most probable values of
DeltaT/TCMB in the 3.5, 6, and 9 cm-1 bands are 4.3 (+2.7, -1.6) x 10-5, 2.8
(+4.3, -1.1) x 10-5, and 3.5 (+3.0, -1.6) x 10-5 (95% confidence upper and
lower limits), respectively.Comment: 16 pages, postscrip
Measurements of Anisotropy in the Cosmic Microwave Background Radiation at Degree Angular Scales Near the Stars Sigma Hercules and Iota Draconis
We present results from two four-frequency observations centered near the
stars Sigma Hercules and Iota Draconis during the fourth flight of the
Millimeter-wave Anisotropy eXperiment (MAX). The observations were made of 6 x
0.6-degree strips of the sky with 1.4-degree peak to peak sinusoidal chop in
all bands. The FWHM beam sizes were 0.55+/-0.05 degrees at 3.5 cm-1 and a
0.75+/-0.05 degrees at 6, 9, and 14 cm-1. Significant correlated structures
were observed at 3.5, 6 and 9 cm-1. The spectra of these signals are
inconsistent with thermal emission from known interstellar dust populations.
The extrapolated amplitudes of synchrotron and free-free emission are too small
to account for the amplitude of the observed structures. If the observed
structures are attributed to CMB anisotropy with a Gaussian autocorrelation
function and a coherence angle of 25', then the most probable values are
DT/TCMB = (3.1 +1.7-1.3) x 10^-5 for the Sigma Hercules scan, and DT/TCMB =
(3.3 +/- 1.1) x 10^-5 for the Iota Draconis scan (95% confidence upper and
lower limits). Finally a comparison of all six MAX scans is presented.Comment: 13 pages, postscript file, 2 figure
Cross-correlating Carbon Monoxide Line-intensity Maps with Spectroscopic and Photometric Galaxy Surveys
Line-intensity mapping (LIM or IM) is an emerging field of observational
work, with strong potential to fit into a larger effort to probe large-scale
structure and small-scale astrophysical phenomena using multiple complementary
tracers. Taking full advantage of such complementarity means, in part,
undertaking line-intensity surveys with galaxy surveys in mind. We consider the
potential for detection of a cross-correlation signal between COMAP and blind
surveys based on photometric redshifts (as in COSMOS) or based on spectroscopic
data (as with the HETDEX survey of Lyman- emitters). We find that
obtaining accuracy in redshifts and
sources per Mpc with spectroscopic redshift determination
should enable a CO-galaxy cross spectrum detection significance at least twice
that of the CO auto spectrum. Either a future targeted spectroscopic survey or
a blind survey like HETDEX may be able to meet both of these requirements.Comment: 19 pages + appendix (31 pages total), 16 figures, 6 tables; accepted
for publication in Ap
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