Ovules from flowers were removed 2 days post anthesis from greenhouse-grown plants of the salt-tolerant cotton (Gossypium hirsutum L.) cultivar 'Acala 1517-88' and the salt-sensitive cotton ...cultivars: 'Deltapine 50', 'MAR-LBCBHGDPIS-1-91', and 'Coker 312'. The ovules were grown in culture media amended with either 0 mM (control conditions) or 100 mM (stress conditions) NaCl and analyzed at 24 days post anthesis for differences in ovule fresh weights and antioxidant enzyme activities. Salt treatment reduced ovule fresh weight in all cultivars except Acala 1517-88. Superoxide dismutase activity increased under salt treatment in Acala 1517-88 and MAR-LBCBHGDPIS-1-91, but not in Coker 312 or Deltapine 50. Catalase activity was constitutively high in Acala 1517-88, and NaCl-induced changes were recorded in MAR-LBCBHGDPIS-1-91 and Coker 312, but not in Deltapine 50. Glutathione reductase activity was constitutively high in Acala 1517-88, increased significantly in MAR-LBCBHGDPIS-1-91 and Coker 312 under NaCl stress, and decreased significantly in Deltapine 50 ovules subjected to a high concentration of NaCl. Under stress conditions, peroxidase activity increased significantly in MAR-LBCBHGDPIS-1-91 and Acala 1517-88 and decreased significantly in Coker 312 and Deltapine 50. High constitutive levels of ascorbate peroxidase activity were observed in Acala 1517-88 and Deltapine 50. The activity of this enzyme increased in MAR-LBCBHGDPIS-1-91 and Coker 312 ovules subjected to NaCl stress. Glutathione-S-transferase activity significantly increased in all the cultivars treated with NaCl. These findings indicate that ovules from the more salt-tolerant cultivar did not exhibit a reduction in growth when subjected to NaCl stress and furthermore suggest this variation may be partially due to the varietal differences in the activities of the antioxidant enzymes.
We present a catalog of compact sources derived from the QUaD Galactic Plane Survey. The survey covers ~800 square degrees of the inner galaxy (|b|<4 degrees) in Stokes I, Q and U parameters at 100 ...and 150 GHz, with angular resolution 5 and 3.5 arcminutes. 505 unique sources are identified in I, of which 239 are spatially matched between frequency bands, with 50 (216) detected at 100 (150) GHz alone; 182 sources are identified as ultracompact HII (UCHII) regions. Approximating the distribution of total intensity source fluxes as a power-law, we find a slope of \(\gamma_{S,100}=-1.8\pm0.4\) at 100 GHz, and \(\gamma_{S,150}=-2.2\pm0.4\) at 150 GHz. Similarly, the power-law index of the source two-point angular correlation function is \(\gamma_{\theta,100}=-1.21\pm0.04\) and \(\gamma_{\theta,150}=-1.25\pm0.04\). The total intensity spectral index distribution peaks at \(\alpha_{I}\sim0.25\), indicating that dust emission is not the only source of radiation produced by these objects between 100 and 150 GHz; free-free radiation is likely significant in the 100 GHz band. Four sources are detected in polarized intensity P, of which three have matching counterparts in I. Three of the polarized sources lie close to the galactic center, Sagittarius A*, Sagittarius B2 and the Galactic Radio Arc, while the fourth is RCW 49, a bright HII region. An extended polarized source, undetected by the source extraction algorithm on account of its \(\sim0.5^{\circ}\) size, is identified visually, and is an isolated example of large-scale polarized emission oriented distinctly from the bulk galactic dust polarization.
We present a survey of ~800 square degrees of the galactic plane observed with the QUaD telescope. The primary product of the survey are maps of Stokes I, Q and U parameters at 100 and 150 GHz, with ...spatial resolution 5 and 3.5 arcminutes respectively. Two regions are covered, spanning approximately 245-295 and 315-5 degrees in galactic longitude l, and -4<b<+4 degrees in galactic latitude b. At 0.02 degree square pixel size, the median sensitivity is 74 and 107 kJy/sr at 100 GHz and 150 GHz respectively in I, and 98 and 120 kJy/sr for Q and U. In total intensity, we find an average spectral index of 2.35+/-0.01 (stat) +/- 0.02 (sys) for |b|<1 degree, indicative of emission components other than thermal dust. A comparison to published dust, synchrotron and free-free models implies an excess of emission in the 100 GHz QUaD band, while better agreement is found at 150 GHz. A smaller excess is observed when comparing QUaD 100 GHz data to WMAP 5-year W band; in this case the excess is likely due to the wider bandwidth of QUaD. Combining the QUaD and WMAP data, a two-component spectral fit to the inner galactic plane (|b|<1 degree) yields mean spectral indices of -0.32 +/- 0.03 and 2.84 +/- 0.03; the former is interpreted as a combination of the spectral indices of synchrotron, free-free and dust, while the second is attributed largely to the thermal dust continuum. In the same galactic latitude range, the polarization data show a high degree of alignment perpendicular to the expected galactic magnetic field direction, and exhibit mean polarization fraction 1.38+/-0.08 (stat) +/-0.1 (sys) % at 100 GHz and 1.70 +/- 0.06 (stat) +/- 0.1 (sys) % at 150GHz. We find agreement in polarization fraction between QUaD 100 GHz and WMAP W band, the latter giving 1.1 +/- 0.4 %.
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 degree by 2 degree region centered on Cen A with QUaD, a CMB polarimeter whose absolute polarization angle is known to 0.5 degrees. 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 -30.0 +/- 1.1 degrees and -29.1 +/- 1.7 degrees. 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 dataset into temperature and polarization subsets and show that the best-fit confidence regions for the LCDM 6-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 dataset using the optimal pivot scale of k_p=0.013 Mpc-1 to be {omch2, ombh2, H_0, A_s, n_s, tau}= {0.113, 0.0224, 70.6, 2.29 times 10^-9, 0.960, 0.086}.
We present an improved analysis of the final dataset 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 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 we find between our two fully independent analysis pipelines. For the standard 6-parameter 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 ACBAR 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 l = 200 and l = 2000, we constrain the amplitude of B-modes to be < 0.57 micro-K^2 (95% c.l.).
We present measurements of the cosmic microwave background (CMB) radiation temperature anisotropy in the multipole range 2000<ell<3000 from the QUaD telescope's second and third observing seasons. ...After masking the brightest point sources our results are consistent with the primary LCDM 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 chi^2. We also fit a standard SZ template to the bandpowers and see no strong evidence of an SZ contribution, which is as expected for sigma_8 approx 0.8.
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 CMB photons. We measure the rotation angle due to such a possible "cosmological birefringence" to be 0.55 deg. +/- 0.82 deg. (random) +/- 0.5 deg. (systematic) using QUaD's 100 and 150 GHz TB and EB spectra over the multipole range 200 < l < 2000, consistent with null, and constrain Lorentz violating interactions to < 2^-43 GeV (68% confidence limit). This is the best constraint to date on electrodynamic parity violation on cosmological scales.
