Search NASA⌕ Search

SEARCH · Search NASA

Results for “Quarantine”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

The rapid change in mental health among college students after introduction of on-campus quarantine during the 2022 Shanghai COVID-19 lockdown

Objectives Among the various impacts of disasters in terms of emotions, quarantine has been proven to result in significant increases in mental health problems. Studies of psychological resilience during outbreaks of epidemics tend to focus on long-term social quarantine. In contrast, insufficient studies have been conducted examining how rapidly negative mental health outcomes occur and how these outcomes change over time. We evaluated the time course of psychological resilience (over three different phases of quarantine) among students at Shanghai Jiao Tong University to investigate the influence of unexpected changes on college students. Methods An online survey was conducted from 5 to 7 April 2022. A structured online questionnaire was administered using a retrospective cohort trial design. Before 9 March (Period 1), individuals engaged in their usual activities without restrictions. From 9 to 23 March (Period 2), the majority of students were asked to remain in their dormitories on campus. From 24 March to early April (Period 3), restrictions were relaxed, and students were gradually allowed to participate in essential activities on campus. We quantified dynamic changes in the severity of students’ depressive symptoms over the course of these three periods. The survey consisted of five sets of self-reported questions: demographic information, lifestyle/activity restrictions, a brief mental health history, COVID-19-related background, and the Beck Depression Inventory, second edition. Results A total of 274 college students aged 18–42 years (mean = 22.34; SE = 0.24) participated in the study (58.39% undergraduate students, 41.61% graduate students; 40.51% male, 59.49% female). The proportion of students with depressive symptoms was 9.1% in Period 1, 36.1% in Period 2, and 34.67% in Period 3. Depressive symptoms increased notably with the introduction of the quarantine in Periods 2 and 3. Lower satisfaction with the food supplied and a longer duration of physical exercise per day were found to be positively associated with changes in depression severity in Periods 2 and 3. Quarantine-related psychological distress was more evident in students who were in a romantic relationship than in students who were single. Conclusion Depressive symptoms in university students rapidly increased after 2 weeks of quarantine and no perceptible reversal was observed over time. Concerning students in a relationship, ways to take physical exercise and to relax should be provided and the food supplied should be improved when young people are quarantined.

Ma, Dongni↗
NASA NTRS1973

Terrestrial quarantine considerations for unmanned sample return missions

For the purpose of understanding some of the possible implications of a terrestrial quarantine constraint on a mission and for developing a basic approach which can be used to demonstrate compliance beyond that developed for Apollo, a terrestrial quarantine study was performed. It is shown that some of the basic tools developed and used by the planetary quarantine community have applicability to terrestrial quarantine analysis. By using these tools, it is concluded that: (1) the method of biasing the earth aiming point when returning from the planet is necessary but, by itself, may not satisfy terrestrial quarantine constraints; and (2) spacecraft and container design significantly influence contamination transfer.

Hoffman, A. R.↗
NASA NTRS1975

A new methodology to integrate planetary quarantine requirements into mission planning, with application to a Jupiter orbiter

A new methodology is proposed for integrating planetary quarantine objectives into space exploration planning. This methodology is designed to remedy the major weaknesses inherent in the current formulation of planetary quarantine requirements. Application of the methodology is illustrated by a tutorial analysis of a proposed Jupiter Orbiter mission. The proposed methodology reformulates planetary quarantine planning as a sequential decision problem. Rather than concentrating on a nominal plan, all decision alternatives and possible consequences are laid out in a decision tree. Probabilities and values are associated with the outcomes, including the outcome of contamination. The process of allocating probabilities, which could not be made perfectly unambiguous and systematic, is replaced by decomposition and optimization techniques based on principles of dynamic programming. Thus, the new methodology provides logical integration of all available information and allows selection of the best strategy consistent with quarantine and other space exploration goals.

Howard, R. A.↗
NASA NTRS1971

Foundations of planetary quarantine.

Discussion of some of the problems in microbiology and engineering involved in the implementation of planetary quarantine. It is shown that the solutions require new knowledge in both disciplines for success at low cost in terms of both monetary outlay and man's further exploration of the planets. A related problem exists in that engineers are not accustomed to the wide variation of biological data and microbiologists must learn to work and think in more exact terms. Those responsible for formulating or influencing national and international policies must walk a tightrope with delicate balance between unnecessarily stringent requirements for planetary quarantine on the one hand and prevention of contamination on the other. The success of planetary quarantine measures can be assured only by rigorous measures, each checked, rechecked, and triple-checked to make sure that no errors have been made and that no factor has been overlooked.

Hall, L. B.↗
NASA NTRS1971

Analytical basis for planetary quarantine.

The attempt is made to investigate quarantine constraints, and alternatives for meeting them, in sufficient detail for identifying those courses of action which compromise neither the quarantine nor the space mission objectives. Mathematical models pertinent to this goal are formulated at three distinct levels. The first level of mission constraint models pertains to the quarantine goals considered necessary by the international scientific community. The principal emphasis of modeling at this level is to quantify international considerations and to produce well-defined mission constraints. Such constraints must be translated into explicit implementation requirements by the operational agency of the launching nation. This produces the second level of implementation system modeling. However, because of the multitude of factors entering into the implementation models, it is convenient to consider these factors at the third level of implementation parameter models. These models are intentionally limited to the inclusion of only those factors which can be quantified realistically, either now or in the near future.

Schalkowsky, S.↗
NASA NTRS1974

The planetary quarantine program: Origins and achievements, 1956 - 1973

United States effort in planetary quarantine is outlined, beginning with the expressions of alarm by biologists, then discussing how a program was put together and implemented, and finally indicating the academic, governmental, institutional, and industrial agencies and people involved. It ends with a brief summary of the accomplishments and present status of the Planetary Quarantine Program and will serve as a partial explanation of how the planetary quarantine effort evolved and reached its present position.

Phillips, C. R.↗
NASA NTRS1975

Objectives and models of the planetary quarantine program

The objectives of the planetary quarantine program are presented and the history of early contamination prevention efforts is outlined. Contamination models which were previously established are given and include: determination of parameters; symbol nomenclature; and calculations of contamination and hazard probabilities. Planetary quarantine is discussed as an issue of national and international concern. Information on international treaty and meetings on spacecraft sterilization, quarantine standards, and policies is provided. The specific contamination probabilities of the U.S.S.R. Venus 3 flyby are included.

Werber, M.↗
NASA NTRS1975

The lunar quarantine program

The lunar quarantine program was designed to ensure that return of lunar material represented no threat to the public health, to agriculture, or to other living resources. It established definitely that no life exists on the moon. The crews of the three lunar quarantine missions, Apollo 11, 12, and 14, experienced no health problems as a result of their exposure to lunar samples. Plants and animals also showed no adverse effects. Stringent quarantine was terminated after Apollo 14, but lunar samples continued to be protected to guarantee that scientists would receive uncontaminated materials for study.

Richard S. Johnston↗
NASA NTRS1988

Lunar placement of Mars quarantine facility

Advanced mission scenarios are currently being contemplated that would call for the retrieval of surface samples from Mars, from a comet, and from other places in the solar system. An important consideration for all of these sample return missions is quarantine. Quarantine facilities on the Moon offer unique advantages over other locations. The Moon offers gravity, distance, and vacuum. It is sufficiently near the Earth to allow rapid resupply and easy communication. It is sufficiently distant to lessen the psychological impact of a quarantine facility on Earth's human inhabitants. Finally, the Moon is airless, and seems to be devoid of life. It is, therefore, more suited to contamination control efforts.

Davidson, James E.↗
DOE OSTI2024

Phyllosticta paracitricarpa is synonymous with the EU quarantine fungus P. citricarpa based on phylogenomic analyses

Phyllosticta citricarpa is an important citrus-pathogen and a quarantine organism in the European Union. Its recently described relative, P. paracitricarpa, is very closely related and not listed as a quarantine organism. P. paracitricarpa is very difficult to distinguish from P. citricarpa, since its morphological features overlap and the barcoding gene sequences that were originally used to delimit them as distinct species have a low number of species-specific polymorphisms that have subsequently been shown to overlap between the two clades. Therefore, we performed extensive genomic analyses to determine whether the genetic variation between P. citricarpa and P. paracitricarpa strains should be considered to represent infraspecific variation within P. citricarpa, or whether it is indicative of distinct species. Using a phylogenomic analysis with 3,000 single copy ortholog genes and whole-genome comparisons, we determined that the variation between P. citricarpa and P. paracitricarpa can be considered as infraspecies variation within P. citricarpa. We also determined the level of variation in mitochondrial assemblies of several Phyllosticta species and concluded there are only minimal differences between the assemblies of P. citricarpa and P. paracitricarpa. Thus, using several orthogonal approaches, we here demonstrate that variation within the nuclear and mitochondrial genomes of other Phyllosticta species is larger than variation between genomes obtained from P. citricarpa and P. paracitricarpa strains. Thus, P. citricarpa and P. paracitricarpa should be considered as conspecific.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1972

Planning, evaluation and analytical studies in planetary quarantine and spacecraft sterilization

The technical and analytical support used to aid in developing requirements for planetary quarantine are presented. The investigation was divided into 8 work tasks which are presented in tabular form. Data include methods of sterilization, safety margins for quarantine, revision of contamination logs for Mars and Venus, and estimates of encapsulated and 'free' microbial burden.

Source record↗
NASA NTRS1971

Planetary quarantine: Principles, methods, and problems.

Microbial survival in deep space environment, contamination of planets by nonsterile flight hardware, and hazards of back contamination are among the topics covered in papers concerned with the analytical basis for planetary quarantine. The development of the technology and policies of planetary quarantine is covered in contributions on microbiologic assay and sterilization of space flight hardware and control of microbial contamination. A comprehensive subject index is included. Individual items are abstracted in this issue.

Hall, L. B.↗
NASA NTRS1973

Quarantine constraints as applied to satellites

Plans for unmanned missions to planets beyond Mars in the 1970s include satellite encounters. Recently published observations of data for Titan, a satellite of Saturn, indicate that conditions may be hospitable for the growth of microorganisms. Therefore, the problem of satisfying possible quarantine constraints for outer planet satellites was investigated. This involved determining the probability of impacting a satellite of Jupiter or Saturn by a spacecraft for a planned satellite encounter during an outer planet mission. Mathematical procedures were formulated which determine the areas in the aim-plane that would result in trajectories that impact the satellite and provide a technique for numerically integrating the navigation error function over the impact area to obtain impact probabilities. The results indicate which of the planned spacecraft trajectory correction maneuvers are most critical in terms of satellite quarantine violation.

Hoffman, A. R.↗
NASA NTRS1973

Scientific and technical services directed toward the development of planetary quarantine measures for automated spacecraft

Planetary quarantine requirements and parameters are evaluated for their effects upon automated spacecraft flights data describing the heat resistance of naturally occuring microorganisms and sterilization requirements are analyzed and a possible method for assessment of these data is developed. Pertinent data from planetary mission microbial contamination logs are compiled and maintained in the quarantine document system.

Source record↗
NASA NTRS1973

Quarantine constraints as applied to satellites.

Plans for unmanned missions to planets beyond Mars in the 1970s include satellite encounters. Recently published observations of data for Titan, a satellite of Saturn, indicate that conditions may be hospitable for the growth of microorganisms. Therefore, the problem of satisfying possible quarantine constraints for outer planet satellites was investigated. This involved determining the probability of impacting a satellite of Jupiter or Saturn by a spacecraft for a planned satellite encounter during an outer planet mission. Mathematical procedures were formulated which (1) determine the areas in the aim-plane that would result in trajectories that impact the satellite and (2) provide a technique for numerically integrating the navigation error function over the impact area to obtain impact probabilities. The results indicate which of the planned spacecraft trajectory correction maneuvers are most critical in terms of satellite quarantine violation.

Hoffman, A. R.↗
NASA NTRS1974

Scientific and technical services directed toward the development of planetary quarantine measures for automated spacecraft

The work is reported, which was performed in the specific tasks of the Planetary Quarantine research program for developing parameter specifications of unmanned scientific missions to the planets. The effort was directed principally toward the advancement of the quarantine technology, applicable to all future missions to planets of biological interest. The emphasis of the research was on coordinated evaluation, analysis, documentation, and presentation of PQ requirements for flight projects such as Viking and Pioneer.

Source record↗