This book includes 13 papers concerning some of the recent progress in the theory of function spaces and its applications. The involved function spaces include Morrey and weak Morrey spaces, ...Hardy-type spaces, John–Nirenberg spaces, Sobolev spaces, and Besov and Triebel–Lizorkin spaces on different underlying spaces, and they are applied in the study of problems ranging from harmonic analysis to potential analysis and partial differential equations, such as the boundedness of paraproducts and Calderón operators, the characterization of pointwise multipliers, estimates of anisotropic logarithmic potential, as well as certain Dirichlet problems for the Schrödinger equation.
If you have ever wondered about space travel, now you have the opportunity to understand it more fully than ever before. Traveling into space and even emigrating to nearby worlds may soon become part ...of the human experience. Scientists, engineers, and investors are working hard to make space tourism and colonization a reality. As astronauts can attest, extraterrestrial travel is incomparably thrilling. To make the most of the experience requires serious physical and mental adaptations in virtually every aspect of life, from eating to intimacy. Everyone who goes into space sees Earth and life on it from a profoundly different perspective than they had before liftoff. Astronomer and former NASA/ASEE scientist Neil F. Comins has written the go-to book for anyone interested in space exploration. He describes the wonders that travelers will encounter—weightlessness, unparalleled views of Earth and the cosmos, and the opportunity to walk on another world—as well as the dangers: radiation, projectiles, unbreathable atmospheres, and potential equipment failures. He also provides insights into specific trips to destinations including suborbital flights, space stations, the Moon, asteroids, comets, and Mars—the top candidate for colonization. Although many challenges are technical, Comins outlines them in clear language for all readers. He synthesizes key issues and cutting-edge research in astronomy, physics, biology, psychology, and sociology to create a complete manual for the ultimate voyage.
An economic historian argues that privately funded space exploration is not a new development, but a trend beginning with the astronomical observatories of the nineteenth centuryOver the last ...half-century there has been a rapid expansion in commerce off the surface of our planet. Nations and corporations have placed hundreds of satellites that provide billions of dollars' worth of communications, scientific, global positioning, and commercial services, while construction has been completed on humanity's ninth and largest space station. On the planet itself, government agencies, corporations, and individuals plan for the expansion of economic development to the lunar surface, asteroids, and Mars. The future of space exploration seems likely to include a mix of large government funded missions as well as independent private-sector missions.The Long Space Ageexamines the economic history of American space exploration and spaceflight, from early astronomical observatories to the International Space Station, and argues that the contemporary rise of private-sector efforts is the re-emergence of a long-run trend not a new phenomenon.
Projective versions of selection principles Bonanzinga, Maddalena; Cammaroto, Filippo; Matveev, Mikhail
Topology and its applications,
04/2010, Letnik:
157, Številka:
5
Journal Article
Recenzirano
Odprti dostop
All spaces are assumed to be Tychonoff. A space
X is called projectively
P
(where
P
is a topological property) if every continuous second countable image of
X is
P
. Characterizations of projectively ...Menger spaces
X in terms of continuous mappings
f
:
X
→
R
ω
, of Menger base property with respect to separable pseudometrics and a selection principle restricted to countable covers by cozero sets are given. If all finite powers of
X are projectively Menger, then all countable subspaces of
C
p
(
X
)
have countable fan tightness. The class of projectively Menger spaces contains all Menger spaces as well as all
σ-pseudocompact spaces, and all spaces of cardinality less than
d
. Projective versions of Hurewicz, Rothberger and other selection principles satisfy properties similar to the properties of projectively Menger spaces, as well as some specific properties. Thus,
X is projectively Hurewicz iff
C
p
(
X
)
has the Monotonic Sequence Selection Property in the sense of Scheepers;
βX is Rothberger iff
X is pseudocompact and projectively Rothberger. Embeddability of the countable fan space
V
ω
into
C
p
(
X
)
or
C
p
(
X
,
2
)
is characterized in terms of projective properties of
X.
To understand the health impact of long-duration spaceflight, one identical twin astronaut was monitored before, during, and after a 1-year mission onboard the International Space Station; his twin ...served as a genetically matched ground control. Longitudinal assessments identified spaceflight-specific changes, including decreased body mass, telomere elongation, genome instability, carotid artery distension and increased intima-media thickness, altered ocular structure, transcriptional and metabolic changes, DNA methylation changes in immune and oxidative stress-related pathways, gastrointestinal microbiota alterations, and some cognitive decline postflight. Although average telomere length, global gene expression, and microbiome changes returned to near preflight levels within 6 months after return to Earth, increased numbers of short telomeres were observed and expression of some genes was still disrupted. These multiomic, molecular, physiological, and behavioral datasets provide a valuable roadmap of the putative health risks for future human spaceflight.
The Space Age began just as the struggle for civil rights forced Americans to confront the long and bitter legacy of slavery, discrimination, and violence against African Americans. Presidents John ...F. Kennedy and Lyndon Johnson utilized the space program as an agent for social change, using federal equal employment opportunity laws to open workplaces at NASA and NASA contractors to African Americans while creating thousands of research and technology jobs in the Deep South to ameliorate poverty. We Could Not Fail tells the inspiring, largely unknown story of how shooting for the stars helped to overcome segregation on earth. Richard Paul and Steven Moss profile ten pioneer African American space workers whose stories illustrate the role NASA and the space program played in promoting civil rights. They recount how these technicians, mathematicians, engineers, and an astronaut candidate surmounted barriers to move, in some cases literally, from the cotton fields to the launching pad. The authors vividly describe what it was like to be the sole African American in a NASA work group and how these brave and determined men also helped to transform Southern society by integrating colleges, patenting new inventions, holding elective office, and reviving and governing defunct towns. Adding new names to the roster of civil rights heroes and a new chapter to the story of space exploration, We Could Not Fail demonstrates how African Americans broke the color barrier by competing successfully at the highest level of American intellectual and technological achievement.
Advances over the past decades in space flight technology have allowed U.S., Russian, and other space programs to not only increase the frequency of manned space flights but also to increase the ...duration of these flights. As such, a large body of knowledge has been developed regarding the ways in which space flight affects the health of the personnel involved. Now, for the first time, this body of clinical knowledge on how to diagnose and treat conditions that either develop during a mission or because of a mission has been compiled by Drs. Michael R. Barratt and Sam L. Pool of the NASA/Johnson Space Center.
Awake craniotomy (AC) is a common neurosurgical procedure for the resection of lesions in eloquent brain areas, which has the advantage of avoiding general anesthesia to reduce associated ...complications and costs. A significant resource limitation in low- and middle-income countries constrains the usage of AC.
To review the published literature on AC in African countries, identify challenges, and propose pragmatic solutions by practicing neurosurgeons in Africa.
We conducted a scoping review under Preferred Reporting Items for Systematic Reviews and Meta-Analysis-Scoping Review guidelines across 3 databases (PubMed, Scopus, and Web of Science). English articles investigating AC in Africa were included.
Nineteen studies consisting of 396 patients were included. Egypt was the most represented country with 8 studies (42.1%), followed by Nigeria with 6 records (31.6%). Glioma was the most common lesion type, corresponding to 120 of 396 patients (30.3%), followed by epilepsy in 71 patients (17.9%). Awake-awake-awake was the most common protocol used in 7 studies (36.8%). Sixteen studies (84.2%) contained adult patients. The youngest reported AC patient was 11 years old, whereas the oldest one was 92. Nine studies (47.4%) reported infrastructure limitations for performing AC, including the lack of funding, intraoperative monitoring equipment, imaging, medications, and limited human resources.
Despite many constraints, AC is being safely performed in low-resource settings. International collaborations among centers are a move forward, but adequate resources and management are essential to make AC an accessible procedure in many more African neurosurgical centers.
Defends and transforms naturalism and materialism to show how culture itself is formed by nature. Bryant endorses a pan-ecological theory of being, arguing that societies are ecosystems that can only ...be understood by considering nonhuman material agencies such as rivers and mountain ranges alongside signifying agencies such as discourses, narratives and ideologies.
The technology of the next few decades could possibly allow us to explore with robotic probes the closest stars outside our Solar System, and maybe even observe some of the recently discovered ...planets circling these stars. This book looks at the reasons for exploring our stellar neighbors and at the technologies we are developing to build space probes that can traverse the enormous distances between the stars. In order to reach the nearest stars, we must first develop a propulsion technology that would take our robotic probes there in a reasonable time. Such propulsion technology has radically different requirements from conventional chemical rockets, because of the enormous distances that must be crossed. Surprisingly, many propulsion schemes for interstellar travel have been suggested and await only practical engineering solutions and the political will to make them a reality. This is a result of the tremendous advances in astrophysics that have been made in recent decades and the perseverance and imagination of tenacious theoretical physicists. This book explores these different propulsion schemes - all based on current physics - and the challenges they present to physicists, engineers, and space exploration entrepreneurs. This book will be helpful to anyone who really wants to understand the principles behind and likely future course of interstellar travel and who wants to recognizes the distinctions between pure fantasy (such as Star Trek's 'warp drive') and methods that are grounded in real physics and offer practical technological solutions for exploring the stars in the decades to come. Kelvin Long was born in Cambridge, England. He holds a Bachelors degree in Aerospace Engineering and a Masters degree in Astrophysics, both from Queen Mary College University of London. He has been a college and university teacher and served for several years in the Parachute Regiment Volunteer Reserve of the British Army. He currently works as a physicist in industry. He has published numerous papers and articles on the subject of astrophysics and space exploration and is currently the Assistant Editor of the Journal of the British Interplanetary Society. He has also contributed to many other publications on interstellar travel. He has appeared on the Austrian Broadcasting Radio Station FM4 as well as in the documentary How to Colonize the Stars produced by Christian Darkin. He is a Fellow of the Royal Astronomical Society, a chartered member of the Institute of Physics, a member of The Planetary Society, a member of the American Institute of Aeronautics Astronautics, Fellow of the British Interplanetary Society, and an associate member of the International Association for Astronomical Artists. He is a Practitioner of the Tau Zero Foundation, which actively promotes and coordinates international research into interstellar flight and within this capacity was the co-founder of an interstellar research initiative called Project Icarus. He is happily married to Gemma and likes to spend his spare time reading and writing science fiction, spacecraft model building, and using his Schmidt-Cassegrain telescope.
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