We present an improved analysis of the final data set from the QUaD experiment. Using an improved technique to remove ground contamination, we double the effective sky area and hence increase the ...precision of our cosmic microwave background (CMB) power spectrum measurements by ~30% versus that previously reported. In addition, we have improved our modeling of the instrument beams and have reduced our absolute calibration uncertainty from 5% to 3.5% in temperature. The robustness of our results is confirmed through extensive jackknife tests, and by way of the agreement that we find between our two fully independent analysis pipelines. For the standard six-parameter Delta *LCDM model, the addition of QUaD data marginally improves the constraints on a number of cosmological parameters over those obtained from the WMAP experiment alone. The impact of QUaD data is significantly greater for a model extended to include either a running in the scalar spectral index, or a possible tensor component, or both. Adding both the QUaD data and the results from the Arcminute Cosmology Bolometer Array Receiver experiment, the uncertainty in the spectral index running is reduced by ~25% compared to WMAP alone, while the upper limit on the tensor-to-scalar ratio is reduced from r < 0.48 to r < 0.33 (95% c.l.). This is the strongest limit on tensors to date from the CMB alone. We also use our polarization measurements to place constraints on parity-violating interactions to the surface of last scattering, constraining the energy scale of Lorentz violating interactions to <1.5 X 10-43 GeV (68% c.l.). Finally, we place a robust upper limit on the strength of the lensing B-mode signal. Assuming a single flat band power between = 200 and = 2000, we constrain the amplitude of B-modes to be <0.57 Delta *mK2 (95% c.l.).
We report results from the second and third seasons of observation with the QUaD experiment. Angular power spectra of the cosmic microwave background are derived for both temperature and polarization ...at both 100 GHz and 150 GHz, and as cross-frequency spectra. All spectra are subjected to an extensive set of jackknife tests to probe for possible systematic contamination. For the implemented data cuts and processing technique such contamination is undetectable. We analyze the difference map formed between the 100 and 150 GHz bands and find no evidence of foreground contamination in polarization. The spectra are then combined to form a single set of results which are shown to be consistent with the prevailing LCDM model. The sensitivity of the polarization results is considerably better than that of any previous experiment-for the first time multiple acoustic peaks are detected in the E-mode power spectrum at high significance.
Imidazolinone-herbicide-resistant Clearfield™ (CL) rice allows the selective chemical control of red rice (
Oryza sativa L.), a major weed problem in rice-growing areas of the southern US, using ...herbicides that otherwise are toxic to the crop. However, selection imposed by the herbicide of resistant individuals resulting from gene flow, and of naturally tolerant individuals, is a major concern. Experiments were conducted at the Rice Research and Extension Center, Stuttgart, AR, US in 2002–2004 to evaluate the effects of cultivar, distance from pollen source, and planting date on natural outcrossing between CL rice and Stuttgart strawhull red rice. The experiments were planted in a split-plot design with planting date (April and May) as main plot and cultivar (CL121 and CL161) as subplots. An encircle-population combination technique was used to determine distance from the rice pollen source at which hybrids were detected. Resistance of the F
1 plants was determined by repeated spraying of imazethapyr, and DNA analysis using SSR primer RM 180 to confirm hybrids. All resistant red rice plants were confirmed hybrids. Outcrossing was higher with CL161 (0.008%) than with CL121 (0.003%) regardless of planting date. Averaged over cultivars, outcrossing rate between April (0.004%) and May (0.006%) plantings did not differ. The majority of hybrids were located within 1
m from CL rice. However, a few hybrids were found up to 6
m from the CL rice, which was the limit of detection in these experiments. All F
1 hybrids were taller and had longer flag leaves than their parents. F
1 hybrids had rough texture and pale-colored leaves similar to the red rice parent. Gene flow between CL rice and red rice is a concern, and even at the low outcrossing rates in these experiments, approximately 170 resistant plants/ha resulted.
We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment's second and third seasons of observations by searching for a possible systematic ...rotation of the polarization directions of cosmic microwave background photons. We measure the rotation angle due to such a possible "cosmological birefringence" to be 0.55 degrees +/-0.82 degrees (random) +/-0.5 degrees (systematic) using QUaD's 100 and 150 GHz temperature-curl and gradient-curl spectra over the spectra over the multipole range 200<l<2000, consistent with null, and constrain Lorentz-violating interactions to <2 x 10;{-43} GeV (68% confidence limit). This is the best constraint to date on electrodynamic parity violation on cosmological scales.
We present measurements of the cosmic microwave background (CMB) radiation temperature anisotropy in the multipole range 2000 < < 3000 from the QUaD telescope's second and third observing seasons. ...After masking the brightest point sources our results are consistent with the primary Lambda CDM expectation alone. We estimate the contribution of residual (un-masked) radio point sources using a model calibrated to our own bright source observations, and a full simulation of the source finding and masking procedure. Including this contribution slightly improves the xi 2. We also fit a standard Sunyaev-Zel'dovich (SZ) template to the bandpowers and see no strong evidence of an SZ contribution, which is as expected for sigma 8 0.8.
The introduction of Clearfield (CL) rice cultivars resistant to imidazolinone herbicides, acetolactate synthase (ALS) inhibitors, has raised concerns of gene flow to weedy rice genotypes collectively ...called “red rice” that infest rice-growing areas in the southern United States. This experiment was conducted to study hybridization between CL rice and red rice using simple sequence repeats (SSR) markers, identify mutations in the ALS gene of imazethapyr-resistant red rice, and to detect the introgression of the ALS-resistant gene from CL rice into red rice. Natural outcrossing experiments between CL rice and strawhull (SH) red rice were set up in Stuttgart, AR, in 2002 and 2003. Putative red rice hybrids were detected among volunteer plants in the following year. Hybridization was confirmed using SSR markers, and introgression of the resistant ALS gene from CL rice to red rice was detected by ALS gene sequencing. The ALS gene sequences of U.S. rice cultivars ‘Bengal’ and ‘Cypress’, SH red rice, CL rice (CL161), and imazethapyr-resistant red rice/CL rice hybrids were compared. Nucleotide sequences of the ALS gene from the rice cultivars were identical. Three point mutations were present in the SH red rice ALS gene coding region relative to Bengal/Cypress. One of these resulted in the substitution of Asp630 for Glu630. The ALS gene sequences of confirmed hybrids were identical to that of the herbicide-resistant pollen source, CL161. We identified four ALS gene mutations in the herbicide-resistant red rice hybrids relative to the susceptible rice cultivars. One point mutation, resulting in a substitution of Ser653 with Asn, was linked to ALS resistance in callus tissue derived from a Kinmaze rice line from Japan. The other three mutations (Ser186—Pro, Lys416—Glu, and Leu662—Pro) are novel. This experiment confirmed that gene flow from imidazolinone-resistant rice resulted in herbicide-resistant red rice plants. Nomenclature: Imazethapyr; red rice, Oryza sativa L. ORSAT; rice, Oryza sativa L.
QUaD is a bolometric CMB polarimeter sited at the South Pole, operating at frequencies of 100 and 150 GHz. In this paper we report preliminary results from the first season of operation (austral ...winter 2005). All six CMB power spectra are presented derived as cross spectra between the 100 and 150 GHz maps using 67 days of observation in a low foreground region of approximately 60 deg super(2). These data are a small fraction of the data acquired to date. The measured spectra are consistent with the ACDM cosmological model. We perform jackknife tests that indicate that the observed signal has negligible contamination from instrumental systematics. In addition, by using a frequency jackknife we find no evidence for foreground contamination.
We describe the QUaD experiment, a millimeter-wavelength polarimeter designed to observe the cosmic microwave background (CMB) from a site at the South Pole. The experiment comprises a 2.64 m ...Cassegrain telescope equipped with a cryogenically cooled receiver containing an array of 62 polarization-sensitive bolometers. The focal plane contains pixels at two different frequency bands, 100 GHz and 150 GHz, with angular resolutions of 5' and 35, respectively. The high angular resolution allows observation of CMB temperature and polarization anisotropies over a wide range of scales. The instrument commenced operation in early 2005 and collected science data during three successive Austral winter seasons of observation.
Centaurus (Cen) A represents one of the best candidates for an isolated, compact, highly polarized source that is bright at typical cosmic microwave background (CMB) experiment frequencies. We ...present measurements of the 4° × 2° region centered on Cen A with QUaD, a CMB polarimeter whose absolute polarization angle is known to an accuracy of 0fdg5. Simulations are performed to assess the effect of misestimation of the instrumental parameters on the final measurement and systematic errors due to the field's background structure and temporal variability from Cen A's nuclear region are determined. The total (Q, U) of the inner lobe region is (1.00 ± 0.07(stat.) ± 0.04(sys.), - 1.72 ± 0.06 ± 0.05) Jy at 100 GHz and (0.80 ± 0.06 ± 0.06, - 1.40 ± 0.07 ± 0.08) Jy at 150 GHz, leading to polarization angles and total errors of -30fdg0 ± 1fdg1 and -29fdg1 ± 1fdg7. These measurements will allow the use of Cen A as a polarized calibration source for future millimeter experiments.
We evaluate the contribution of cosmic microwave background (CMB) polarization spectra to cosmological parameter constraints. We produce cosmological parameters using high-quality CMB polarization ...data from the ground-based QUaD experiment and demonstrate for the majority of parameters that there is significant improvement on the constraints obtained from satellite CMB polarization data. We split a multi-experiment CMB data set into temperature and polarization subsets and show that the best-fit confidence regions for the ΛCDM six-parameter cosmological model are consistent with each other, and that polarization data reduces the confidence regions on all parameters. We provide the best limits on parameters from QUaD EE/BB polarization data and we find best-fit parameters from the multi-experiment CMB data set using the optimal pivot scale of kp = 0.013 Mpc-1 to be {h 2Ω c , h 2Ω b , H 0, As , ns , τ} = {0.113, 0.0224, 70.6, 2.29 × 10-9, 0.960, 0.086}.
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