RESUMO
A detailed overview of the knowledge gaps in our understanding of the heliospheric interaction with the largely unexplored Very Local Interstellar Medium (VLISM) are provided along with predictions of with the scientific discoveries that await. The new measurements required to make progress in this expanding frontier of space physics are discussed and include in-situ plasma and pick-up ion measurements throughout the heliosheath, direct sampling of the VLISM properties such as elemental and isotopic composition, densities, flows, and temperatures of neutral gas, dust and plasma, and remote energetic neutral atom (ENA) and Lyman-alpha (LYA) imaging from vantage points that can uniquely discern the heliospheric shape and bring new information on the interaction with interstellar hydrogen. The implementation of a pragmatic Interstellar Probe mission with a nominal design life to reach 375 Astronomical Units (au) with likely operation out to 550 au are reported as a result of a 4-year NASA funded mission study.
RESUMO
To evaluate the potential risk of pulmonary damage due to aerial spraying of the insecticide fenitrothion, rat lungs were examined under light and electron microscopy at 3, 7, 21, and 60 days after exposure. Rats were exposed by a "nose-only" apparatus for 1 hr to 2 or 500 mg/m3 of aerosolized fenitrothion (15%) mixed with solvent Cyclosol 63 (35%) and diluent oil 585 (50%). Aerosol size particles were monitored by a light scattering apparatus. Only minor modifications of lung alveolar tissues were observed after exposure to the high concentration. At 3 days, discrete foci of mild inflammation were detected, including interstitial edema, cellular infiltration, and increased number of alveolar macrophages. At 7 days, signs of irritation were diminished while at 21 and 60 days alveolar tissues were essentially normal. Exposure to lower concentration induced more limited changes at 3 days; no modifications were seen at later periods. It is concluded that a single exposure to this fenitrothion mixture at 500 mg/m3 presents no serious hazard of pulmonary toxicity.