Three-mirror anastigmat for cosmic microwave background observations.

An off-axis three-mirror anastigmat is proposed for future cosmic microwave background observations. The telescope has a 5 m diameter primary, giving 1.5' angular resolution at λ=2 mm, which is sufficient for measurements of gravitational lensing and for galaxy cluster surveys. The design includes several key features, not previously combined in a large telescope, that are important for sensitive measurements, especially on large angular scales: (1) high throughput (8° diameter diffraction-limited field of view at λ=1 mm, and 12×8° at λ=3 mm, so a single telescope could support all the detectors for an optimistic, future experiment); (2) low scattering (all the mirrors are small enough to be monolithic, so there are no segment gaps); (3) full boresight rotation, over the full elevation range, for measuring polarization errors; and (4) a comoving shield or baffle around the entire telescope to control pickup.

Inexpensive mount for a large millimeter-wavelength telescope.

A telescope mount with a single-point force support at the center of gravity of the primary mirror is proposed in order to eliminate much of the structure and cost of a large, millimeter-wavelength telescope. The single-point support gives repeatable thermal and gravitational deformation, so the surface of the primary can be controlled based on lookup tables for elevation and temperature. The new design is most appropriate for a survey telescope because locating the support above the vertex of the primary limits the range of motion of the mount to about 1 rad. A 30 m diameter, λ=850 µm telescope with the proposed mount is a factor of 4 lighter than a design with a conventional elevation-over-azimuth mount, and roughly half the cost.

Rayleigh beacon for measuring the surface profile of a radio telescope.

Millimeter-wavelength Rayleigh scattering from water droplets in a cloud is proposed as a means of generating a bright beacon for measuring the surface profile of a radio telescope. A λ=3 mm transmitter, with an output power of a few watts, illuminating a stratiform cloud, can generate a beacon with the same flux as Mars in 10 GHz bandwidth, but the beacon has a narrow line width, so it is extremely bright. The key advantage of the beacon is that it can be used at any time, and positioned anywhere in the sky, as long as there are clouds.

Detection of B-mode polarization in the cosmic microwave background with data from the South Pole Telescope.

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

Frequency multiplexed superconducting quantum interference device readout of large bolometer arrays for cosmic microwave background measurements.

A technological milestone for experiments employing transition edge sensor bolometers operating at sub-Kelvin temperature is the deployment of detector arrays with 100s-1000s of bolometers. One key technology for such arrays is readout multiplexing: the ability to read out many sensors simultaneously on the same set of wires. This paper describes a frequency-domain multiplexed readout system which has been developed for and deployed on the APEX-SZ and South Pole Telescope millimeter wavelength receivers. In this system, the detector array is divided into modules of seven detectors, and each bolometer within the module is biased with a unique ∼MHz sinusoidal carrier such that the individual bolometer signals are well separated in frequency space. The currents from all bolometers in a module are summed together and pre-amplified with superconducting quantum interference devices operating at 4 K. Room temperature electronics demodulate the carriers to recover the bolometer signals, which are digitized separately and stored to disk. This readout system contributes little noise relative to the detectors themselves, is remarkably insensitive to unwanted microphonic excitations, and provides a technology pathway to multiplexing larger numbers of sensors.

South Pole Telescope optics.

The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber.

Polarization observations with the Cosmic Background Imager.

Polarization observations of the cosmic microwave background with the Cosmic Background Imager from September 2002 to May 2004 provide a significant detection of the E-mode polarization and reveal an angular power spectrum of polarized emission showing peaks and valleys that are shifted in phase by half a cycle relative to those of the total intensity spectrum. This key agreement between the phase of the observed polarization spectrum and that predicted on the basis of the total intensity spectrum provides support for the standard model of cosmology, in which dark matter and dark energy are the dominant constituents, the geometry is close to flat, and primordial density fluctuations are predominantly adiabatic with a matter power spectrum commensurate with inflationary cosmological models.

Laboratory evaluation of chemical-biological control of the rice weevil (Sitophilus oryzae L.) in stored grains.

The virulence of ten different fungal isolates of: Beauveria bassiana, Metarhizium anisopliae, Verticillium lecanii and Paecilomyces farinosus to the rice weevil Sitophilus oryzae was tested. A fungal mix of the most efficient isolates, B. bassiana ARSEF 5500+M. anisopliae ARSEF 2974, which caused the highest mortality, was assayed in combination with fenitrothion at a concentration lower (3 ppm) than the normal 6 ppm. Fungal inoculation of insects was done by spraying conidial suspensions of each fungus on wheat. Insecticide formulations were added by spraying wheat. Treated and untreated insects were incubated on durum wheat. Insects were kept in a climatized chamber for 30 days. Observations were performed at 7, 14 and 30 days to record insect mortality. Highly significant differences were demonstrated for B. bassiana 5500 and 5501 and for M. anisopliae 2974. The level of mortality produced by treatments was: 6 ppm insecticide=97.50%, B. bassiana ARSEF 5500+M. anisopliae ARSEF 2974+3 ppm insecticide=74.17%, B. bassiana ARSEF 5500+M.anisopliae ARSEF 2974=50% and 3 ppm insecticide=37.50%. There was a statistically significant difference (p<0.05) among treatments.

Cardiografía de impedancia para la determinación del volumen minuto / Impedance cardiography for determination of cardiac output and its correlation with thermodilution

Se presenta la comparación de la medición del volumen minuto con un cardiógrafo de impedancia desarrollado por los autores con los resultados del método de termodilución. Las mediciones efectuadas en sujetos sanos mostraron hasta un 30 por ciento de variación (estudio de repetitividad). Las determinaciones en pacientes mostraron que la correlación aplicando la fórmula de Kubiceck (17 casos) fue de 0,72 en basales, posinotrópicos 0,92 y posbetabloqueantes 0,94. Con la ecuación de Srameck (14 casos) la correlación fue menor. Concluímos que actualmente la aplicación clínica del método es poco precisa por la amplia variabilidad en sanos y las fuentes potenciales de error en pacientes con patología

Cardiografía de impedancia para la determinación del volumen minuto / Impedance cardiography for determination of cardiac output and its correlation with thermodilution

Se presenta la comparación de la medición del volumen minuto con un cardiógrafo de impedancia desarrollado por los autores con los resultados del método de termodilución. Las mediciones efectuadas en sujetos sanos mostraron hasta un 30 por ciento de variación (estudio de repetitividad). Las determinaciones en pacientes mostraron que la correlación aplicando la fórmula de Kubiceck (17 casos) fue de 0,72 en basales, posinotrópicos 0,92 y posbetabloqueantes 0,94. Con la ecuación de Srameck (14 casos) la correlación fue menor. Concluímos que actualmente la aplicación clínica del método es poco precisa por la amplia variabilidad en sanos y las fuentes potenciales de error en pacientes con patología (AU)