Direct measurements of the polarization of terrestrial kilometric radiation from Voyagers 1 and 2

Terrestrial radiation measurements obtained with planetary radio astronomy experiments on Voyager-1 and 2 during the early portions of each flight show the signals to be predominantly left-hand circularly polarized. Since these emissions were most probably generated above the Northern Hemisphere auroral zone, it is concluded that the radiation is emitted primarily in the extraordinary mode

Increase in whole-body peripheral vascular resistance during three hours of air or oxygen prebreathing

Male and female subjects prebreathed air or 100% oxygen through a mask for 3.0 hours while comfortably reclined. Blood pressures, heart rate, and cardiac output were collected before and after the prebreathe. Peripheral vascular resistance (PVR) was calculated from these parameters and increased by 29% during oxygen prebreathing and 15% during air prebreathing. The oxygen contributed substantially to the increase in PVR. Diastolic blood pressure increased by 18% during the oxygen prebreathe while stystolic blood pressure showed no change under either procedure. The increase in PVR during air prebreathing was attributed to procedural stress common to air and oxygen prebreathing

Voyager spacecraft radio observations of Jupiter: Initial cruise results

Jupiter's low-frequency radio emission were detected by the planetary radio astronomy instruments onboard the two Voyager spacecraft. The emission is surprisingly similar in morphology but opposite in polarization to the high-frequency Jovian radio noise that were observed with ground-based telescopes for more than two decades. Several possible explanations for the behavior of the low-frequency emission are examined, but none of them is completely satisfactory

Observations Suggesting a Possible Link Between Gammacarboxyglutamic Acid and Porcine Bioprosthetic Valve Calcification

Observations that link gammacarboxyglutamic acid (Gla) peptides with ectopic calcification are accumulating in the literature and may be summarized as follows: 1) Gla peptides selectively bind calcium and hydroxyapatite. 2) The presence of detectable levels of Gla in calcified tissue is concurrent with the onset of mineralization. 3) In an animal model, osteocalcin (a Gla-containing protein) accounts for more than 90% of all the Gla found in the resulting subcutaneously implanted calcified leaflet. 4) Vitamin D stimulates osteocalcin synthesis in cultures of osteosarcoma cells, and in vitamin D deficient rats subcutaneously implanted valve leaflets are not calcified. 5) Gla content and the degree of calcification in degenerated porcine bioprosthetic valves removed from humans are positively correlated. 6) Porcine bioprosthetic valves implanted in children are calcified more rapidly than those of adults, and the normal GIa levels in the urine of children are more than twice those of normal adults

Voyager 1 Planetary Radio Astronomy Observations Near Jupiter

Results are reported from the first low frequency radio receiver to be transported into the Jupiter magnetosphere. Dramatic new information was obtained both because Voyager was near or in Jupiter's radio emission sources and also because it was outside the relatively dense solar wind plasma of the inner solar system. Extensive radio arcs, from above 30 MHz to about 1 MHz, occurred in patterns correlated with planetary longitude. A newly discovered kilometric wavelength radio source may relate to the plasma torus near Io's orbit. In situ wave resonances near closest approach define an electron density profile along the Voyager trajectory and form the basis for a map of the torus. Studies in progress are outlined briefly

The evolution of plasticity of dauer larva developmental arrest in the nematode Caenorhabditis elegans.

Organisms can end up in unfavourable conditions and to survive this they have evolved various strategies. Some organisms, including nematodes, survive unfavourable conditions by undergoing developmental arrest. The model nematode Caenorhabditis elegans has a developmental choice between two larval forms, and it chooses to develop into the arrested dauer larva form in unfavourable conditions (specifically, a lack of food and high population density, indicated by the concentration of a pheromone). Wild C. elegans isolates vary extensively in their dauer larva arrest phenotypes, and this prompts the question of what selective pressures maintain such phenotypic diversity? To investigate this we grew C. elegans in four different environments, consisting of different combinations of cues that can induce dauer larva development: two combinations of food concentration (high and low) in the presence or absence of a dauer larva-inducing pheromone. Five generations of artificial selection of dauer larvae resulted in an overall increase in dauer larva formation in most selection regimes. The presence of pheromone in the environment selected for twice the number of dauer larvae, compared with environments not containing pheromone. Further, only a high food concentration environment containing pheromone increased the plasticity of dauer larva formation. These evolutionary responses also affected the timing of the worms' reproduction. Overall, these results give an insight into the environments that can select for different plasticities of C. elegans dauer larva arrest phenotypes, suggesting that different combinations of environmental cues can select for the diversity of phenotypically plastic responses seen in C. elegans.We would like to thank Henrique Teotonio for the gift of the G140.A population, Louise Hughes and Laura Weldon for technical help, two anonymous reviewers for their comments, and NERC for funding.This is the final published version of the article. It was originally published in Ecology and Evolution (Diaz SA, Viney M, Ecology and Evolution 2015, 5(6), 1343–1353, doi:10.1002/ece3.1436) http://dx.doi.org/10.1002/ece3.143

Radial Velocities of Six OB Stars

We present new results from a radial velocity study of six bright OB stars with little or no prior measurements. One of these, HD 45314, may be a long-period binary, but the velocity variations of this Be star may be related to changes in its circumstellar disk. Significant velocity variations were also found for HD 60848 (possibly related to nonradial pulsations) and HD 61827 (related to wind variations). The other three targets, HD 46150, HD 54879, and HD 206183, are constant velocity objects, but we note that HD 54879 has H$\alpha$ emission that may originate from a binary companion. We illustrate the average red spectrum of each target.Comment: Accepted for publication in PASP July 2007 issu