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57 records – page 1 of 6.

Source
Sci Am. 2010 May;302(5):66-73
Publication Type
Article
Date
May-2010
Author
Matthew Sturm
Author Affiliation
U.S. Army Corps of Engineers, USA.
Source
Sci Am. 2010 May;302(5):66-73
Date
May-2010
Language
English
Publication Type
Article
Keywords
Alaska
Arctic Regions
Fires
Global warming
Ice Cover
Photography
Plants - growth & development
Spacecraft
Trees - growth & development
World War II
PubMed ID
20443380 View in PubMed
Less detail

Assimilation of satellite data to 3D hydrodynamic model of Lake Säkylän Pyhäjärvi.

https://arctichealth.org/en/permalink/ahliterature267761
Source
Water Sci Technol. 2015;71(7):1033-9
Publication Type
Article
Date
2015
Author
Akiko Mano
Olli Malve
Sampsa Koponen
Kari Kallio
Antti Taskinen
Janne Ropponen
Janne Juntunen
Ninni Liukko
Source
Water Sci Technol. 2015;71(7):1033-9
Date
2015
Language
English
Publication Type
Article
Keywords
Environmental Monitoring - methods
Eutrophication
Finland
Hydrodynamics
Lakes - analysis
Models, Theoretical
Remote Sensing Technology
Spacecraft
Water Quality
Abstract
To analyze the applicability of direct insertion of total suspended matter (TSM) concentration field based on turbidity derived from satellite data to numerical simulation, dispersion studies of suspended matter in Lake Säkylän Pyhäjärvi (lake area 154 km²; mean depth 5.4 m) were conducted using the 3D COHERENS simulation model. To evaluate the practicality of direct insertion, five cases with different initialization frequencies were conducted: (1) every time, when satellite data were available; (2) every 10 days; (3) 20 days; (4) 30 days; and (5) control run without repeated initialization. To determine the effectiveness of initialization frequency, three methods of comparison were used: simple spatial differences of TSM concentration without biomass in the lake surface layer; averaged spatial differences between initialization data and the forecasts; and time series of TSM concentration and observation data at 1 m depth at the deepest point of the lake. Results showed that direct insertion improves the forecast significantly, even if it is applied less often.
PubMed ID
25860706 View in PubMed
Less detail

Biohazard potential of putative Martian organisms during missions to Mars.

https://arctichealth.org/en/permalink/ahliterature163488
Source
Aviat Space Environ Med. 2007 Apr;78(4 Suppl):A79-88
Publication Type
Article
Date
Apr-2007
Author
David Warmflash
Maia Larios-Sanz
Jeffrey Jones
George E Fox
David S McKay
Author Affiliation
Department of Biology and Biochemistry, University of Houston, TX, USA. dwarmfla@ems.jsc.nasa.gov
Source
Aviat Space Environ Med. 2007 Apr;78(4 Suppl):A79-88
Date
Apr-2007
Language
English
Publication Type
Article
Keywords
Aerospace Medicine
Astronauts
Containment of Biohazards
Environmental Microbiology
Environmental monitoring
Exobiology
Extraterrestrial Environment
Humans
Life
Mars
Risk
Space Flight
Spacecraft
United States
United States National Aeronautics and Space Administration
Weightlessness
Abstract
Exploration Class missions to Mars will require precautions against potential contamination by any native microorganisms that may be incidentally pathogenic to humans. While the results of NASA's Viking biology experiments of the 1970s have been generally interpreted as inconclusive for surface organisms, and attributed to active but nonbiological chemistries, the possibility of native surface life has never been ruled out completely. It is possible that, prior to the first human landing on Mars, robotic craft and sample return missions will provide enough data to know with certainty whether future human landing sites harbor extant life forms. If native life were found to exist, it would be problematic to determine whether any of its species might present a medical danger to astronauts. Therefore, it will become necessary to assess empirically the risk that the planet contains pathogens based on terrestrial examples of pathogenicity and to take a reasonably cautious approach to biohazard protection. A survey of terrestrial pathogens was conducted with special emphasis on those whose evolution has not depended on the presence of animal hosts. The history of the development and implementation of Apollo anti-contamination protocol and recommendations of the National Research Council's Space Studies Board regarding Mars were reviewed. Organisms can emerge in Nature in the absence of indigenous animal hosts and both infectious and non-infectious human pathogens are therefore theoretically possible on Mars. Although remote, the prospect of Martian surface life, together with the existence of a diversity of routes by which pathogenicity has emerged on Earth, suggests that the probability of human pathogens on Mars, while low, is not zero. Still, since the discovery and study of Martian life can have long-term benefits for humanity, the risk that Martian life might include pathogens should not be an obstacle to human exploration. As a precaution, it is recommended that EVA (extravehicular activity) suits be decontaminated when astronauts enter surface habitats upon returning from field activity and that biosafety protocols approximating laboratory BSL 2 be developed for astronauts working in laboratories on the Martian surface. Quarantine of astronauts and Martian materials arriving on Earth should also be part of a human mission to Mars, and this and the surface biosafety program should be integral to human expeditions from the earliest stages of the mission planning.
PubMed ID
17511302 View in PubMed
Less detail

Blood lead concentrations in Alaskan tundra swans: linking breeding and wintering areas with satellite telemetry.

https://arctichealth.org/en/permalink/ahliterature263055
Source
Ecotoxicology. 2014 Apr;23(3):349-56
Publication Type
Article
Date
Apr-2014
Author
Craig R Ely
J Christian Franson
Source
Ecotoxicology. 2014 Apr;23(3):349-56
Date
Apr-2014
Language
English
Publication Type
Article
Keywords
Alaska
Animal Migration
Animals
Anseriformes - physiology
Environmental Monitoring - methods
Female
Lead - blood
Lead Poisoning - veterinary
Male
Reproduction
Spacecraft
Telemetry
Abstract
Tundra swans (Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low (
PubMed ID
24468922 View in PubMed
Less detail

Bubble-detector measurements in the Russian segment of the International Space Station during 2009-12.

https://arctichealth.org/en/permalink/ahliterature266545
Source
Radiat Prot Dosimetry. 2015 Jan;163(1):1-13
Publication Type
Article
Date
Jan-2015
Author
M B Smith
S. Khulapko
H R Andrews
V. Arkhangelsky
H. Ing
B J Lewis
R. Machrafi
I. Nikolaev
V. Shurshakov
Source
Radiat Prot Dosimetry. 2015 Jan;163(1):1-13
Date
Jan-2015
Language
English
Publication Type
Article
Keywords
Cosmic Radiation
Humans
Linear Energy Transfer
Neutrons
Phantoms, Imaging
Radiation Dosage
Radiation Monitoring - instrumentation - methods
Radiation Protection
Russia
Space Flight
Spacecraft - instrumentation
Time Factors
Abstract
Measurements using bubble detectors have been performed in order to characterise the neutron dose and energy spectrum in the Russian segment of the International Space Station (ISS). Experiments using bubble dosemeters and a bubble-detector spectrometer, a set of six detectors with different energy thresholds that is used to determine the neutron spectrum, were performed during the ISS-22 (2009) to ISS-33 (2012) missions. The spectrometric measurements are in good agreement with earlier data, exhibiting expected features of the neutron energy spectrum in space. Experiments using a hydrogenous radiation shield show that the neutron dose can be reduced by shielding, with a reduction similar to that determined in earlier measurements using bubble detectors. The bubble-detector data are compared with measurements performed on the ISS using other instruments and are correlated with potential influencing factors such as the ISS altitude and the solar activity. Surprisingly, these influences do not seem to have a strong effect on the neutron dose or energy spectrum inside the ISS.
PubMed ID
24714114 View in PubMed
Less detail

Bubble-detector measurements of neutron radiation in the international space station: ISS-34 to ISS-37.

https://arctichealth.org/en/permalink/ahliterature278704
Source
Radiat Prot Dosimetry. 2016 Feb;168(2):154-66
Publication Type
Article
Date
Feb-2016
Author
M B Smith
S. Khulapko
H R Andrews
V. Arkhangelsky
H. Ing
M R Koslowksy
B J Lewis
R. Machrafi
I. Nikolaev
V. Shurshakov
Source
Radiat Prot Dosimetry. 2016 Feb;168(2):154-66
Date
Feb-2016
Language
English
Publication Type
Article
Keywords
Cosmic Radiation
Equipment Design
Humans
Monte Carlo Method
Neutrons
Phantoms, Imaging
Radiation Dosage
Radiation Monitoring - methods
Russia
Spacecraft
Abstract
Bubble detectors have been used to characterise the neutron dose and energy spectrum in several modules of the International Space Station (ISS) as part of an ongoing radiation survey. A series of experiments was performed during the ISS-34, ISS-35, ISS-36 and ISS-37 missions between December 2012 and October 2013. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, included measurements in four modules of the US orbital segment: Columbus, the Japanese experiment module, the US laboratory and Node 2. The Radi-N2 dose and spectral measurements are not significantly different from the Radi-N results collected in the same ISS locations, despite the large difference in solar activity between 2009 and 2013. Parallel experiments using a second set of detectors in the Russian segment of the ISS included the first characterisation of the neutron spectrum inside the tissue-equivalent Matroshka-R phantom. These data suggest that the dose inside the phantom is ~70% of the dose at its surface, while the spectrum inside the phantom contains a larger fraction of high-energy neutrons than the spectrum outside the phantom. The phantom results are supported by Monte Carlo simulations that provide good agreement with the empirical data.
PubMed ID
25899609 View in PubMed
Less detail

[Calculation of radiation loads in a space station compartment with a secondary shielding].

https://arctichealth.org/en/permalink/ahliterature104658
Source
Aviakosm Ekolog Med. 2013 Nov-Dec;47(6):61-6
Publication Type
Article
Author
D A Kartashov
R V Tolochek
V A Shurshakov
E N Yarmanova
Source
Aviakosm Ekolog Med. 2013 Nov-Dec;47(6):61-6
Language
Russian
Publication Type
Article
Keywords
Astronauts
Cosmic Radiation
Humans
Radiation Dosage
Radiation Injuries - prevention & control
Radiation Protection - instrumentation
Russia
Spacecraft
Abstract
Doses from space ionizing radiation were estimated using a model of ISS cosmonaut's quarters (CQ) outfitted with secondary shielding ("Protective shutter" (PS) as part of experiment MATRYOSHKA-R). Protective shutter is a "blanket" of water-containing material with mass thickness of - 6 g/cm2 covering the CQ exterior wall. Calculation was performed specifically for locations of experimental dosimetry assemblies. Agreement of calculations and experimental data reaching accuracy - 15% proves model applicability to estimating protective effectiveness of secondary shielding in the present-day and future space vehicles. This shielding may reduce radiation loading onto crewmembers as an equivalent dose by more than 40% within a broad range of orbit altitudes equally during the solar minimum and maximum.
PubMed ID
24660246 View in PubMed
Less detail

Challenges of assuring crew safety in space shuttle missions with international cargoes.

https://arctichealth.org/en/permalink/ahliterature182930
Source
Acta Astronaut. 2004 Feb;54(3):215-9
Publication Type
Article
Date
Feb-2004
Author
C. Vongsouthy
P A Stenger-Nguyen
H V Nguyen
P H Nguyen
M C Huang
R G Alexander
Author Affiliation
Boeing North American, Inc., Reusable Space Systems, Downey, CA, USA.
Source
Acta Astronaut. 2004 Feb;54(3):215-9
Date
Feb-2004
Language
English
Publication Type
Article
Keywords
Accidents, Aviation - prevention & control
Astronauts
Equipment Design
Extravehicular Activity
Human Engineering
Humans
International Cooperation
Life Support Systems - instrumentation
Russia
Safety Management
Space Flight - instrumentation - organization & administration
Spacecraft - instrumentation
United States
United States National Aeronautics and Space Administration
Weightlessness
Abstract
The top priority in America's manned space flight program is the assurance of crew and vehicle safety. This priority gained greater focus during and after the Space Shuttle return-to-flight mission (STS-26). One of the interesting challenges has been to assure crew safety and adequate protection of the Space Shuttle, as a national resource, from increasingly diverse cargoes and operations. The control of hazards associated with the deployment of complex payloads and cargoes has involved many international participants. These challenges are examined in some detail along with examples of how crew safety has evolved in the manned space program and how the international partners have addressed various scenarios involving control and mitigation of potential hazards to crew and vehicle safety.
PubMed ID
14606499 View in PubMed
Less detail

57 records – page 1 of 6.