We present the first ground-based near-infrared image of the circumstellar disk around the post-Herbig Ae/Be star HD141569A initially detected with the HST. Observations were carried out in the near-IR (2.2 µm) at the Palomar 200-inch telescope using the adaptive optics system PALAO. The main large scale asymmetric features of the disk are detected on our ground-based data. In addition, we measured that the surface brightness of the disk is slightly different than that derived by HST observations (at 1.1 µm and 1.6 µm). We interpret this possible color-effect in terms of dust properties and derive a minimal grain size of 0.6 ± 0.2µm for compact grains and a power law index for the grain size distribution smaller than −3. Basic dynamical considerations are consistent with the presence of a remnant amount of gas in the disk.

Butyrate is a byproduct of microbial carbohydrate fermentation that occurs primarily in the large intestine. When added to feed, butyrate quickly disappears in the upper digestive tract. Because butyrate is important for epithelial cell development, mucosal integrity, and animal growth, an encapsulation technique has been developed that allows for the slow release of butyrate into the small and large intestines. The purpose of this study was to describe the in vitro release of calcium [1-(14)C]butyrate, formulated into a slow-release (protected) bead, into water and simulated intestinal fluids and to compare the in vivo absorption and disposition of unprotected versus protected calcium [1-(14)C]butyrate in broiler chicks. Formulation of calcium [1-(14)C]butyrate into protected beads allowed release of 5.8 ± 0.2 and 3.4 ± 0.2% of the formulated radiocarbon into water and gastric fluid, respectively, after 2 h of incubation. Beads incubated in gastric fluid for 2 h and subsequently incubated in simulated intestinal fluid released a total of 17.4 ± 0.8% of the formulated radioactivity. Release of respiratory [(14)C]CO(2) after oral dosing of aqueous calcium [1-(14)C]butyrate in broiler chicks peaked at 15.2 ± 5.2% per hour 1.5 h after dosing; in contrast, maximal rates of release in chicks dosed with protected calcium [1-(14)C]butyrate occurred 4 h after dosing at 9.0 ± 3.1% per hour. The data suggested an improved efficacy of protected butyrate delivery to intestinal tissues over nonprotected butyrate. This study confirmed that encapsulation strategies designed to enhance delivery of ingredients to improve intestinal health are effective at prolonging intestinal exposure to butyrate. Encapsulation of such ingredients might benefit the food and feed industries.

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Abstract. We present results of a coronographic imaging search for circumstellar dust disks with the Adaptive Optics Near Infrared System (ADONIS) at the ESO 3.6 m telescope in La Silla (Chile). 22 candidate stars, known to be orbited by a planet or to show infrared excess radiation, were examined for circumstellar material. In the PSF-subtracted images no clear disk was found. We further determine the detection sensitivities and outline how remaining atmospheric fluctuations still can hamper adaptive optics observations.

We identify several unusual one-armed density waves in Saturn's Cassini Division, using occultation observations from the Cassini RSS and VIMS instruments. In the inner Cassini Division, we identify outward-propagating density waves with wavenumber m = 1 located near 118,050 km (W118.05), 118,400 km (W118.40), and 118,530 km (W118.53). From Cassini ISS images taken at very low incidence angles we find evidence for vertical structure in these waves, which may be evidence for splashing of ring material in the crests of the waves. We propose that these waves are driven by nearby eccentric ringlets, probably the Strange (or R6) and Herschel ringlets. In the outer Cassini Division, we identify a wave structure near 120,200 km (W120.20), between the Laplace and Bessel gaps, as a conspicuous example of a standing wave in a planetary ring system. It appears to be the superposition of an outward-propagating m = 1 density wave, probably driven by the nearby Laplace ringlet, and its reflection at the inner edge of the Bessel gap.