Mars Tumbleweed: FY2003 Conceptual Design Assessment

NASA LaRC is studying concepts for a new type of Mars exploration vehicle that would be propelled by the wind. Known as the Mars Tumbleweed, it would derive mobility through use of the Martian surface winds. Tumbleweeds could conceivably travel greater distances, cover larger areas of the surface, and provide access to areas inaccessible by conventional vehicles. They would be lightweight and relatively inexpensive, allowing a multiple vehicle network to be deployed on a single mission. Tumbleweeds would be equipped with sensors for conducting science and serve as scouts searching broad areas to identify specific locations for follow-on investigation by other explorers. An extensive assessment of LaRC Tumbleweed concepts was conducted in FY03, including refinement of science mission scenarios, definition of supporting subsystems (structures, power, communications), testing in wind tunnels, and development of a dynamic simulation capability

Sub-micron proximal probe thermal desorption and laser mass spectrometry on painting cross-sections

Cross-sections containing organic dyes are used to demonstrate sub-micron atomic force microscopy thermal desorption (AFM-TD), followed by laser mass spectrometry

Phoenix Is Required for Mechanosensory Hair Cell Regeneration in the Zebrafish Lateral Line

In humans, the absence or irreversible loss of hair cells, the sensory mechanoreceptors in the cochlea, accounts for a large majority of acquired and congenital hearing disorders. In the auditory and vestibular neuroepithelia of the inner ear, hair cells are accompanied by another cell type called supporting cells. This second cell population has been described as having stem cell-like properties, allowing efficient hair cell replacement during embryonic and larval/fetal development of all vertebrates. However, mammals lose their regenerative capacity in most inner ear neuroepithelia in postnatal life. Remarkably, reptiles, birds, amphibians, and fish are different in that they can regenerate hair cells throughout their lifespan. The lateral line in amphibians and in fish is an additional sensory organ, which is used to detect water movements and is comprised of neuroepithelial patches, called neuromasts. These are similar in ultra-structure to the inner ear's neuroepithelia and they share the expression of various molecular markers. We examined the regeneration process in hair cells of the lateral line of zebrafish larvae carrying a retroviral integration in a previously uncharacterized gene, phoenix (pho). Phoenix mutant larvae develop normally and display a morphologically intact lateral line. However, after ablation of hair cells with copper or neomycin, their regeneration in pho mutants is severely impaired. We show that proliferation in the supporting cells is strongly decreased after damage to hair cells and correlates with the reduction of newly formed hair cells in the regenerating phoenix mutant neuromasts. The retroviral integration linked to the phenotype is in a novel gene with no known homologs showing high expression in neuromast supporting cells. Whereas its role during early development of the lateral line remains to be addressed, in later larval stages phoenix defines a new class of proteins implicated in hair cell regeneration

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Sub-micron proximal probe thermal desorption and laser mass spectrometry on painting cross-sections

Cross-sections containing organic dyes are used to demonstrate sub-micron atomic force microscopy thermal desorption (AFM-TD), followed by laser mass spectrometry

Sub-micron proximal probe thermal desorption and laser mass spectrometry on painting cross-sections (vol 6, pg 8940, 2014)

Correction for ‘Sub-micron proximal probe thermal desorption and laser mass spectrometry on painting cross-sections’ by Shawn C. Owens et al., Anal. Methods, 2014, 6, 8940–8945

Sub-micron proximal probe thermal desorption and laser mass spectrometry on painting cross-sections

Cross-sections containing organic dyes are used to demonstrate sub-micron atomic force microscopy thermal desorption (AFM-TD), followed by laser mass spectrometry