Planetary Protection Knowledge Gap Closure Enabling Crewed Missions to Mars.

As focus for exploration of Mars transitions from current robotic explorers to development of crewed missions, it remains important to protect the integrity of scientific investigations at Mars, as well as protect the Earth's biosphere from any potential harmful effects from returned martian material. This is the discipline of planetary protection, and the Committee on Space Research (COSPAR) maintains the consensus international policy and guidelines on how this is implemented. Based on National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) studies that began in 2001, COSPAR adopted principles and guidelines for human missions to Mars in 2008. At that point, it was clear that to move from those qualitative provisions, a great deal of work and interaction with spacecraft designers would be necessary to generate meaningful quantitative recommendations that could embody the intent of the Outer Space Treaty (Article IX) in the design of such missions. Beginning in 2016, COSPAR then sponsored a multiyear interdisciplinary meeting series to address planetary protection "knowledge gaps" (KGs) with the intent of adapting and extending the current robotic mission-focused Planetary Protection Policy to support the design and implementation of crewed and hybrid exploration missions. This article describes the outcome of the interdisciplinary COSPAR meeting series, to describe and address these KGs, as well as identify potential paths to gap closure. It includes the background scientific basis for each topic area and knowledge updates since the meeting series ended. In particular, credible solutions for KG closure are described for the three topic areas of (1) microbial monitoring of spacecraft and crew health; (2) natural transport (and survival) of terrestrial microbial contamination at Mars, and (3) the technology and operation of spacecraft systems for contamination control. The article includes a KG data table on these topic areas, which is intended to be a point of departure for making future progress in developing an end-to-end planetary protection requirements implementation solution for a crewed mission to Mars. Overall, the workshop series has provided evidence of the feasibility of planetary protection implementation for a crewed Mars mission, given (1) the establishment of needed zoning, emission, transport, and survival parameters for terrestrial biological contamination and (2) the creation of an accepted risk-based compliance approach for adoption by spacefaring actors including national space agencies and commercial/nongovernment organizations.

Screening and surveillance for colorectal neoplasia: uncertainties of colonoscopic management.

Over the past decade the use of screening and surveillance modalities has been associated with a small but significant decrease in the incidence of colorectal cancer and an increase in curability of lesions that are found. Although consensus-based international guidelines have stressed the variety of possible diagnostic options that can serve this purpose, in many countries colonoscopy withremoval of all polyps has become the test of choice. The evidence-base for this choice is largely derivative rather than direct and prospective, and many uncertainties remain in its use as a primary screening modality. This review examines our current guidelines relative to risk stratifying the populations offered the test; the onset, interval, and discontinuation of testing; and the important role of operator variability in outcome.

Achieving a high-performance health care system with universal access: what the United States can learn from other countries.

This position paper concerns improving health care in the United States. Unlike previous highly focused policy papers by the American College of Physicians, this article takes a comprehensive approach to improving access, quality, and efficiency of care. The first part describes health care in the United States. The second compares it with health care in other countries. The concluding section proposes lessons that the United States can learn from these countries and recommendations for achieving a high-performance health care system in the United States. The articles are based on a position paper developed by the American College of Physicians' Health and Public Policy Committee. This policy paper (not included in this article) also provides a detailed analysis of health care systems in 12 other industrialized countries. Although we can learn much from other health systems, the College recognizes that our political and social culture, demographics, and form of government will shape any solution for the United States. This caution notwithstanding, we have identified several approaches that have worked well for countries like ours and could probably be adapted to the unique circumstances in the United States.

Inlet patch of gastric mucosa in upper esophagus causing chronic cough and vocal cord dysfunction.

BACKGROUND: An inlet patch of gastric mucosa in the upper esophagus is usually an incidental, congenital finding found during upper gastrointestinal tract endoscopy. Although it has been reported to cause dysphagia, strictures, adenocarcinoma, and webs, it has never been associated with cough and vocal cord dysfunction. OBJECTIVE: To report the first case of a patient with an inlet patch of gastric mucosa in the upper esophagus as the cause of a particularly troublesome, chronic cough that was initially missed on 2 upper endoscopies. METHODS: The patient is a 50-year-old man with a 7-year history of chronic cough associated with hoarseness, shortness of breath, and globus sensation. For diagnostic evaluation, pulmonary function tests, chest computed tomography, rhinolaryngoscopy, upper gastrointestinal tract endoscopy, and histologic examinations were performed. RESULTS: A multidisciplinary approach revealed several possible causes for the chronic cough, including vocal cord dysfunction, postnasal drip syndrome, allergic rhinitis, and mild gastroesophageal reflux disease that was only partially responsive to therapy. The results of 2 initial upper gastrointestinal tract endoscopies were interpreted as normal. A third endoscopy detected an inlet patch of gastric mucosa in the upper esophagus. Treatment with a high-dose histamine type 2 receptor antagonist and a proton pump inhibitor alleviated the patient's symptoms. CONCLUSIONS: An inlet patch of gastric mucosa in the upper esophagus is not uncommon, but it is often overlooked or believed to be an incidental, congenital finding. This is the first report, to our knowledge, of an inlet patch resulting in a troublesome, chronic cough.

Gaseous and particulate emissions released to the atmosphere from vegetation fires

This paper considers the gaseous and particulate species produced during vegetation fires and the procedures to calculate their source strengths. Document in pdf format; Acrobat Reader required.