17 research outputs found
Shelby\u27s Expedition to Mexico: An Unwritten Leaf of the War
Migration to Mexico Ex-Confederates moved from one Civil War to another Most Civil War readers are aware that various parties of ex-Confederates migrated to Mexico shortly after the end of the Civil War. The common assumption may very well be that these immigrants or would-be ...
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 .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the 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
Recommended from our members
Prevention of a First Stroke: A Review of Guidelines and a Multidisciplinary Consensus Statement From the National Stroke Association
OBJECTIVE To establish, in a single resource, up-to-date
recommendations for primary care physicians regarding prevention
strategies for a first stroke. PARTICIPANTS Members of the National Stroke Association's
(NSA's) Stroke Prevention Advisory Board and Cedars-Sinai Health
System Department of Health Services Research convened on April 9,
1998, in an open meeting. The conference attendees, selected to
participate by the NSA, were recognized experts in neurology (9),
cardiology (2), family practice (1), nursing (1), physician assistant
practices (1), and health services research (2). EVIDENCE A literature review was carried out by the Department of
Health Services Research, Cedars-Sinai Health System, Los Angeles,
Calif, using the MEDLINE database search for 1990 through April 1998
and updated in November 1998. English-language guidelines, statements,
meta-analyses, and overviews on prevention of a first stroke were
reviewed. CONSENSUS PROCESS At the meeting, members of the advisory board
identified 6 important stroke risk factors (hypertension, myocardial
infarction [MI], atrial fibrillation, diabetes mellitus, blood
lipids, asymptomatic carotid artery stenosis), and 4 lifestyle factors
(cigarette smoking, alcohol use, physical activity, diet). CONCLUSIONS Several interventions that modify well-documented and
treatable cardiovascular and cerebrovascular risk factors can reduce
the risk of a first stroke. Good evidence for direct stroke reduction
exists for hypertension treatment; using warfarin for patients after MI
who have atrial fibrillation, decreased left ventricular ejection
fraction, or left ventricular thrombus; using 3-hydroxy-3
methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors for patients
after MI; using warfarin for patients with atrial fibrillation and
specific risk factors; and performing carotid endarterectomy for
patients with stenosis of at least 60%. Observational studies support
the role of modifying lifestyle-related risk factors (eg, smoking,
alcohol use, physical activity, diet) in stroke prevention. Measures to
help patients improve adherence are an important component of a stroke
prevention plan