Protecting Bees in Iowa

Beekeepers and commercial pesticide applicators play important roles in protecting Iowa's bees. This publication outlines actions both groups can take to reduce the risks to bees that benefit Iowa's agroecosystem.</p

Recent Cosmic-Ray Antiproton Measurements and Astrophysical Implications

Cosmic-ray antiprotons have been detected by a new balloon-borne experiment which covers the energy range between 130 and 320 MeV. Fourteen detected events yield a measured flux of 1.7±0.5 x 10^(-4) antiprotons m^(-2) sr^(-1) s(-1) MeV^(-1). The corresponding antiproton/proton ratio is 2.2± 0.6 x 10^(-4), only slightly smaller than the ratio observed by other experiments at higher energies. The measured flux is significantly larger than predicted, and some cosmic-ray models which could explain this result are discussed

A Search for Early Optical Emission at Gamma-Ray Burst Locations by the Solar Mass Ejection Imager (SMEI)

The Solar Mass Ejection Imager (SMEI) views nearly every point on the sky once every 102 minutes and can detect point sources as faint as R~10th magnitude. Therefore, SMEI can detect or provide upper limits for the optical afterglow from gamma-ray bursts in the tens of minutes after the burst when different shocked regions may emit optically. Here we provide upper limits for 58 bursts between 2003 February and 2005 April.Comment: accepted for publication in ApJ, 17 pages, 8 figure

A Measurement of the Cosmic-Ray Antiproton Flux and a Search for Antihelium

A balloon-borne instrument has measured the cosmic-ray antiproton flux between 130 and 320 MeV and searched for antihelium between 130 and 370 MeV per nuclear. These particles were selected from the background of normal-matter cosmic rays by combining a selective trigger with a detailed spark chamber visualization of each recorded event. Antiprotons are identified by their characteristic annihilation radiation. Residue from background processes meeting the selection criteria is small. The observed 14 antiprotons yield a measured differential flux of 1.7±0.5X 10^(-4) antiprotons m^(-2) sr(-1) s^(-1)i Mev^(-1) at the top of the atmosphere. The corresponding antiproton/pro-ton ratio is 2.2±0.6X10^(-4), only slightly smaller than the ratio observed by other experiments at higher energies. Thus the antiprotons have a spectral shape similar to the protons, at least down to about 100 MeV. The expected flux of these particles can be calculated under the assumption that they were created by collisions of high-energy cosmic rays with the interstellar gas. Calculations using the standard leaky box model for propagation in the Galaxy predict a flux two orders of magnitude smaller than that observed. A small low-energy flux is predicted due to a kinematic suppression of the production of low-energy antiprotons. The discrepancy between calculations and experiment may be evidence that cosmic-ray protons have passed through substantially more than 5 g cm^(-2) of material during their lifetime. In addition, the combined results from this experiment and previous ones may be evidence for stochastic, energy-changing processes in interstellar space which act upon the secondary antiprotons after their creation. The search for cosmic-ray antihelium sets a 95% confidence level upper limit on the He /He ratio of 2.2 X 10^(-5)

Solar Polar Sail mission: report of a study to put a scientific spacecraft in a circular polar orbit about the sun

The Solar Polar Sail Mission uses solar-sail propulsion to place a spacecraft in a circular orbit 0.48 Au from the Sun with an inclination of 90 degrees. The spacecraft's orbit around the Sun is in 3:1 resonance with Earth phased such that the Earth-Sun-spacecraft angle range from 30 degrees to 150 degrees. The polar view will further our understanding of: (1) the global structure and evolution of the corona, (2) the initiation, evolution, and propagation of coronal mass ejections; (3) the acceleration of the solar wind; (4) the interactions of rotation, magnetic fields, and convection within the Sun; (5) the acceleration and propagation of energetic particles; and (6) the rate of angular momentum loss by the Sun. Candidate imaging instruments are a coronagraph, an all-sky imager for following mass ejections and interaction regions from the Sun to 1 AU, and a disk imager. A lightweight package of fields and particle instruments is included. A mission using a 158 m square sail with an effective areal density of 6 g/m^2 would cost approximately $250-300M (FY97) for all mission phases, including the launch vehicle. This mission depends on the successful development and demonstration of solar-sail propulsion

Environmental Controls and Life Support System (ECLSS) Design for a Multi-Mission Space Exploration Vehicle (MMSEV)

Engineers at Johnson Space Center (JSC) are developing an Environmental Control and Life Support System (ECLSS) design for the Multi-Mission Space Exploration Vehicle (MMSEV). The purpose of the MMSEV is to extend the human exploration envelope for Lunar, Near Earth Object (NEO), or Deep Space missions by using pressurized exploration vehicles. The MMSEV, formerly known as the Space Exploration Vehicle (SEV), employs ground prototype hardware for various systems and tests it in manned and unmanned configurations. Eventually, the system hardware will evolve and become part of a flight vehicle capable of supporting different design reference missions. This paper will discuss the latest MMSEV ECLSS architectures developed for a variety of design reference missions, any work contributed toward the development of the ECLSS design, lessons learned from testing prototype hardware, and the plan to advance the ECLSS toward a flight design

Cosmic-Ray Positrons: Are There Primary Sources?

Cosmic rays at the Earth include a secondary component originating in collisions of primary particles with the diffuse interstellar gas. The secondary cosmic rays are relatively rare but carry important information on the Galactic propagation of the primary particles. The secondary component includes a small fraction of antimatter particles, positrons and antiprotons. In addition, positrons and antiprotons may also come from unusual sources and possibly provide insight into new physics. For instance, the annihilation of heavy supersymmetric dark matter particles within the Galactic halo could lead to positrons or antiprotons with distinctive energy signatures. With the High-Energy Antimatter Telescope (HEAT) balloon-borne instrument, we have measured the abundances of positrons and electrons at energies between 1 and 50 GeV. The data suggest that indeed a small additional antimatter component may be present that cannot be explained by a purely secondary production mechanism. Here we describe the signature of the effect and discuss its possible origin.Comment: 15 pages, Latex, epsfig and aasms4 macros required, to appear in Astroparticle Physics (1999

Solar Polar Sail mission: report of a study to put a scientific spacecraft in a circular polar orbit about the sun

The Solar Polar Sail Mission uses solar-sail propulsion to place a spacecraft in a circular orbit 0.48 Au from the Sun with an inclination of 90 degrees. The spacecraft's orbit around the Sun is in 3:1 resonance with Earth phased such that the Earth-Sun-spacecraft angle range from 30 degrees to 150 degrees. The polar view will further our understanding of: (1) the global structure and evolution of the corona, (2) the initiation, evolution, and propagation of coronal mass ejections; (3) the acceleration of the solar wind; (4) the interactions of rotation, magnetic fields, and convection within the Sun; (5) the acceleration and propagation of energetic particles; and (6) the rate of angular momentum loss by the Sun. Candidate imaging instruments are a coronagraph, an all-sky imager for following mass ejections and interaction regions from the Sun to 1 AU, and a disk imager. A lightweight package of fields and particle instruments is included. A mission using a 158 m square sail with an effective areal density of 6 g/m^2 would cost approximately $250-300M (FY97) for all mission phases, including the launch vehicle. This mission depends on the successful development and demonstration of solar-sail propulsion

Corrigendum: Inflammation and Tissue Remodeling in the Bladder and Urethra in Feline Interstitial Cystitis

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating chronic disease of unknown etiology. A naturally occurring disease termed feline interstitial cystitis (FIC) reproduces many features of IC/BPS patients. To gain insights into mechanisms underlying IC/BPS, we investigated pathological changes in the lamina propria (LP) of the bladder and proximal urethra in cats with FIC, using histological and molecular methods. Compared to control cat tissue, we found an increased number of de-granulated mast cells, accumulation of leukocytes, increased cyclooxygenase (COX)-1 expression in the bladder LP, and increased COX-2 expression in the urethra LP from cats with FIC. We also found increased suburothelial proliferation, evidenced by mucosal von Brunn’s nests, neovascularization and alterations in elastin content. Scanning electron microscopy revealed normal appearance of the superficial urethral epithelium, including the neuroendocrine cells (termed paraneurons), in FIC urethrae. Together, these histological findings suggest the presence of chronic inflammation of unknown origin leading to tissue remodeling. Since the mucosa functions as part of a “sensory network” and urothelial cells, nerves and other cells in the LP are influenced by the composition of the underlying tissues including the vasculature, the changes observed in the present study may alter the communication of sensory information between different cellular components. This type of mucosal signaling can also extend to the urethra, where recent evidence has revealed that the urethral epithelium is likely to be part of a signaling system involving paraneurons and sensory nerves. Taken together, our data suggest a more prominent role for chronic inflammation and tissue remodeling than previously thought, which may result in alterations in mucosal signaling within the urinary bladder and proximal urethra that may contribute to altered sensations and pain in cats and humans with this syndrome