The lipids of spore types B, E, and F and vegetative cell types E and F of Clostridium botulinum

The primary purpose of this investigation was to characterize the lipids of the spores and vegetative cells of Cl. botulinum. A second purpose was to explore the possibility that lipids might serve as a means of differentiating the chiefly proteolytic Cl. botulinum type B from the nonproteolytic Cl. botulinum types E and F. The total lipid extracted accounted for 3.7%, 3.3%, 2.0%, 2.7%, and 3.0% of the dry weight of Cl. botulinum vegetative cell types 61E and F; and spore types 61E, F, and 115B, respectively. The fatty acids were analyzed in the form of their methyl esters by gas-liquid chromatography. Infrared spectroscopy, mercuric acetate fractionation, and silver nitrate-thin layer chromatography served as complementary means of analysis. The total fatty acids included straight chain saturated, unsaturated, and cyclopropane acids. Palmitic and myristic were the predominant acids in both the spores and vegetative cells of types 61E, F, and 115B. Together, they made up over 50% of the total fatty acids. Unsaturated acids were the second major group. These were primarily 7, 8-tetradecenoic, 9, 10-hexadecenoic, 7, 8-hexadecenoic, 11, 12-octadecenoic, and 9, 10-octadecenoic acids, Types E and F possessed an 18-carbon diunsaturate, which was not found in the vegetative cells or spores of type 115B. However, insufficient quantities prevented its further characterization. The vegetative cells and spores also contained C₁₅, C₁₇, C₁₉ cyclopropane fatty acids as adjudged by their infrared spectra and gas-liquid chromatographic behavior. The phospholipids accounted for approximately 60% of the total lipids in the vegetative cells and 40% of that in the spores. The primary phospholipid was phosphatidylethanolamine. Qualitative tests for plasmalogens, glycolipids, and phosphatidic acid were positive for both spores and vegetative cells

UV Absorption Lines from High-Velocity Gas in the Vela Supernova Remnant: New insights from STIS Echelle Observations of HD72089

The star HD72089 is located behind the Vela supernova remnant and shows a complex array of high and low velocity interstellar absorption features arising from shocked clouds. A spectrum of this star was recorded over the wavelength range 1196.4 to 1397.2 Angstroms at a resolving power lambda/Delta lambda = 110,000 and signal-to-noise ratio of 32 by STIS on the Hubble Space Telescope. We have identified 7 narrow components of C I and have measured their relative populations in excited fine-structure levels. Broader features at heliocentric velocities ranging from -70 to +130 km/s are seen in C II, N I, O I, Si II, S II and Ni II. In the high-velocity components, the unusually low abundances of N I and O I, relative to S II and Si II, suggest that these elements may be preferentially ionized to higher stages by radiation from hot gas immediately behind the shock fronts.Comment: 11 pages, 2 figures, Latex. Submitted for the special HST ERO issue of the Astrophysical Journal Letter

Hybrid photonic crystal cavity and waveguide for coupling to diamond NV-centers

A design for an ultra-high Q photonic crystal nanocavity engineered to interact with nitrogen-vacancy (NV) centers located near the surface of a single crystal diamond sample is presented. The structure is based upon a nanowire photonic crystal geometry, and consists of a patterned high refractive index membrane, such as gallium phosphide (GaP), supported by a diamond substrate. The nanocavity supports a mode with quality factor Q > 1.5 million and mode volume V < 0.52 (\lambda/n_\text{GaP})^3, and promises to allow Purcell enhanced collection of spontaneous emission from an NV located more than 50 nm below the diamond surface. The nanowire photonic crystal waveguide can be used to efficiently couple light into and out of the cavity, or as an efficient broadband collector of NV phonon sideband emission. The proposed structures can be fabricated using existing materials and processing techniques

Theory and applications of atomic and ionic polarizabilities

Atomic polarization phenomena impinge upon a number of areas and processes in physics. The dielectric constant and refractive index of any gas are examples of macroscopic properties that are largely determined by the dipole polarizability. When it comes to microscopic phenomena, the existence of alkaline-earth anions and the recently discovered ability of positrons to bind to many atoms are predominantly due to the polarization interaction. An imperfect knowledge of atomic polarizabilities is presently looming as the largest source of uncertainty in the new generation of optical frequency standards. Accurate polarizabilities for the group I and II atoms and ions of the periodic table have recently become available by a variety of techniques. These include refined many-body perturbation theory and coupled-cluster calculations sometimes combined with precise experimental data for selected transitions, microwave spectroscopy of Rydberg atoms and ions, refractive index measurements in microwave cavities, ab initio calculations of atomic structures using explicitly correlated wave functions, interferometry with atom beams, and velocity changes of laser cooled atoms induced by an electric field. This review examines existing theoretical methods of determining atomic and ionic polarizabilities, and discusses their relevance to various applications with particular emphasis on cold-atom physics and the metrology of atomic frequency standards.Comment: Review paper, 44 page

Restoration of Regenerative Osteoblastogenesis in Aged Mice: Modulation of TNF

Skeletal changes accompanying aging are associated with both increased risk of fractures and impaired fracture healing, which, in turn, is due to compromised bone regeneration potential. These changes are associated with increased serum levels of selected proinflammatory cytokines, e.g., tumor necrosis factor α (TNF-α). We have used a unique model of bone regeneration to demonstrate (1) that aged-related deficits in direct bone formation can be restored to young mice by treatment with TNF blockers and (2) that the cyclin-dependent kinase inhibitor p21 is a candidate for mediation of the osteoinhibitory effects of TNF. It has been hypothesized recently that TNF antagonists may represent novel anabolic agents, and we believe that the data presented here represent a successful test of this hypothesis. © 2010 American Society for Bone and Mineral Researc

The James Webb Space Telescope Mission: Optical Telescope Element Design, Development, and Performance

The James Webb Space Telescope (JWST) is a large, infrared space telescope that has recently started its science program which will enable breakthroughs in astrophysics and planetary science. Notably, JWST will provide the very first observations of the earliest luminous objects in the Universe and start a new era of exoplanet atmospheric characterization. This transformative science is enabled by a 6.6 m telescope that is passively cooled with a 5-layer sunshield. The primary mirror is comprised of 18 controllable, low areal density hexagonal segments, that were aligned and phased relative to each other in orbit using innovative image-based wavefront sensing and control algorithms. This revolutionary telescope took more than two decades to develop with a widely distributed team across engineering disciplines. We present an overview of the telescope requirements, architecture, development, superb on-orbit performance, and lessons learned. JWST successfully demonstrates a segmented aperture space telescope and establishes a path to building even larger space telescopes.Comment: accepted by PASP for JWST Overview Special Issue; 34 pages, 25 figure

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

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29

An Evaluation of the Effects of Neighborhood Mobilization on Community Problems

This research examines the outcomes of actions taken by members of a residential neighborhood association to revitalize a neighborhood and to make it a safer and more secure place to live. This urban neighborhood association initiated a major planning process in cooperation with city officials. Residents overwhelmingly adopted the plan that included the creation of mini-neighborhoods with a series of gates to moderate traffic flow, increase neighborliness, and reduce crime. An analysis of official data from police crime reports shows that crime was significantly reduced in the neighborhood after the street changes. This reduction in crime was maintained even five years later. Telephone interviews with neighborhood residents indicated that they perceived reductions in traffic, crime, noise and drug offenses for at least five years after the changes. Even though neighborhood cohesion did not increase, it appears that the actions instigated and promoted by neighborhood association members enhanced the quality of life for neighborhood residents