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1.
Water Res ; 177: 115787, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32315899

RESUMO

Space exploration is demanding longer lasting human missions and water resupply from Earth will become increasingly unrealistic. In a near future, the spacecraft water monitoring systems will require technological advances to promptly identify and counteract contingent events of waterborne microbial contamination, posing health risks to astronauts with lowered immune responsiveness. The search for bio-analytical approaches, alternative to those applied on Earth by cultivation-dependent methods, is pushed by the compelling need to limit waste disposal and avoid microbial regrowth from analytical carryovers. Prospective technologies will be selected only if first validated in a flight-like environment, by following basic principles, advantages, and limitations beyond their current applications on Earth. Starting from the water monitoring activities applied on the International Space Station, we provide a critical overview of the nucleic acid amplification-based approaches (i.e., loop-mediated isothermal amplification, quantitative PCR, and high-throughput sequencing) and early-warning methods for total microbial load assessments (i.e., ATP-metry, flow cytometry), already used at a high readiness level aboard crewed space vehicles. Our findings suggest that the forthcoming space applications of mature technologies will be necessarily bounded by a compromise between analytical performances (e.g., speed to results, identification depth, reproducibility, multiparametricity) and detrimental technical requirements (e.g., reagent usage, waste production, operator skills, crew time). As space exploration progresses toward extended missions to Moon and Mars, miniaturized systems that also minimize crew involvement in their end-to-end operation are likely applicable on the long-term and suitable for the in-flight water and microbiological research.


Assuntos
Voo Espacial , Água , Humanos , Estudos Prospectivos , Reprodutibilidade dos Testes , Astronave
2.
PLoS One ; 15(2): e0227152, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32074104

RESUMO

The opportunistic pathogens Burkholderia cepacia and Burkholderia contaminans, both genomovars of the Burkholderia cepacia complex (BCC), are frequently cultured from the potable water dispenser (PWD) of the International Space Station (ISS). Here, we sequenced the genomes and conducted phenotypic assays to characterize these Burkholderia isolates. All recovered isolates of the two species fall within monophyletic clades based on phylogenomic trees of conserved single-copy core genes. Within species, the ISS-derived isolates all demonstrate greater than 99% average nucleotide identity (with 95-99% of genomes aligning) and share around 90% of the identified gene clusters from a pangenomic analysis-suggesting that the two groups are each composed of highly similar genomic lineages and their members may have all stemmed from the same two founding populations. The differences that can be observed between the recovered isolates at the pangenomic level are primarily located within putative plasmids. Phenotypically, macrophage intracellularization and lysis occurred at generally similar rates between all ISS-derived isolates, as well as with their respective type-terrestrial strain references. All ISS-derived isolates exhibited antibiotic sensitivity similar to that of the terrestrial reference strains, and minimal differences between isolates were observed. With a few exceptions, biofilm formation rates were generally consistent across each species. And lastly, though isolation date does not necessarily provide any insight into how long a given isolate had been aboard the ISS, none of the assayed physiology correlated with either date of isolation or distances based on nucleotide variation. Overall, we find that while the populations of Burkholderia present in the ISS PWS each maintain virulence, they are likely are not more virulent than those that might be encountered on planet and remain susceptible to clinically used antibiotics.


Assuntos
Infecções por Burkholderia/microbiologia , Burkholderia cepacia , Burkholderia , Água Potável/microbiologia , Filogenia , Astronave , Burkholderia/classificação , Burkholderia/isolamento & purificação , Burkholderia/patogenicidade , Burkholderia cepacia/classificação , Burkholderia cepacia/isolamento & purificação , Burkholderia cepacia/patogenicidade , Virulência
3.
PLoS Pathog ; 16(1): e1008153, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31999804

RESUMO

Human space travel is on the verge of visiting Mars and, in the future, even more distant places in the solar system. These journeys will be also made by terrestrial microorganisms (hitchhiking on the bodies of astronauts or on scientific instruments) that, upon arrival, will come into contact with new planetary environments, despite the best measures to prevent contamination. These microorganisms could potentially adapt and grow in the new environments and subsequently recolonize and infect astronauts. An even more challenging situation would be if truly alien microorganisms will be present on these solar system bodies: What will be their pathogenic potential, and how would our immune host defenses react? It will be crucial to anticipate these situations and investigate how the immune system of humans might cope with modified terrestrial or alien microbes. We propose several scenarios that may be encountered and how to respond to these challenges.


Assuntos
Equipamentos e Provisões/microbiologia , Interações Hospedeiro-Patógeno , Sistema Imunitário/imunologia , Astronautas , Exobiologia , Meio Ambiente Extraterreno , Humanos , Voo Espacial , Astronave
4.
Int J Syst Evol Microbiol ; 70(1): 71-76, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31622233

RESUMO

Two Gram-stain-positive, motile, endospore-forming, aerobic strains, designated V44-8T and V47-23aT, were isolated from environmental air sampling at the vehicle assembly building at Cape Canaveral, Florida, where the Viking spacecraft were assembled. Growth was observed at pH 7-9 (optimum, pH 9) for strain V44-8T, and pH 5-10 (pH 9) for strain V47-23aT. Both strains displayed growth in 0-5 % NaCl with an optimum at 1 % for strain V44-8T; 0 % for strain V47-23aT. Strains V44-8T and V47-23aT grew optimally at 32 °C, (15-32 °C) and 25 °C (20-45 °C), respectively. The cell wall of both strains contained meso-diaminopimelic acid as the diagnostic diamino acid. Both strains contained phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol. The predominant cellular fatty acids were anteiso-C15 : 0, iso-C14 : 0 and iso-C15 : 0. Strain V47.23aT shared its highest 16S rRNA sequence similarity with Bacillus cavernae DSM-105484T at 96.9%, and V44.8T with Bacillus zeae DSM-103964T at 96.6 %. Based on their phenotypic characteristics and phylogenetic position inferred from 16S rRNA gene sequence analyses, the isolates were identified as being a members of the genus Bacillus that forms a separate clade when compared to close relatives. Average nucleotide identity and average amino acid identity values between strains V44-8T and DSM-103964T were 72.1% and 67.5 %; V47-23aT and DSM-105484T were 62.4% and 69.1%, respectively. Based on the phenotypic, genomic and biochemical data, strains V44-8T and V47-23aT represent two novel species in the genus Bacillus for which the names Bacillus glennii sp. nov. [type strain, V44-8T (=ATCC BAA-2860T =DSM 105192T)], and Bacillus saganii sp. nov. [V47-23aT (=ATCC BAA-2861T=DSM 105190T)] are proposed.


Assuntos
Microbiologia do Ar , Bacillus/classificação , Filogenia , Astronave , Bacillus/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ambiente Controlado , Ácidos Graxos/química , Florida , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
5.
Chemosphere ; 239: 124678, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494323

RESUMO

In the developing countries such as China, most well-developed areas have suffered severe haze pollution, which was associated with increased premature morbidity and mortality and attracted widespread public concerns. Since ground-based PM2.5 monitoring has limited temporal and spatial coverage, satellite aerosol remote sensing data has been increasingly applied to map large-scale PM2.5 characteristics through advanced spatial statistical models. Although most existing research has taken advantage of the polar orbiting satellite instruments, a major limitation of the polar orbiting platform is its limited sampling frequency (e.g., 1-2 times/day), which is insufficient for capturing the PM2.5 variability during short but intense heavy haze episodes. As the first attempt, we quantitatively investigated the feasibility of using the aerosol optical depth (AOD) data retrieved by the Geostationary Ocean Color Imager (GOCI) to estimate hourly PM2.5 concentrations during winter haze episodes in the Yangtze River Delta (YRD). We developed a three-stage spatial statistical model, using GOCI AOD and fine mode fraction, as well as corresponding monitoring PM2.5 concentrations, meteorological and land use data on a 6-km modeling grid with complete coverage in time and space. The 10-fold cross-validation R2 was 0.72 with a regression slope of 1.01 between observed and predicted hourly PM2.5 concentrations. After gap filling, the R2 value for the three-stage model was 0.68. We further analyzed two representative large regional episodes, i.e., a "multi-process diffusion episode" during December 21-26, 2015 and a "Chinese New Year episode" during February 7-8, 2016. We concluded that AOD retrieved by geostationary satellites could serve as a new valuable data source for analyzing the heavy air pollution episodes.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Tecnologia de Sensoriamento Remoto/métodos , Aerossóis/análise , China , Meteorologia , Modelos Estatísticos , Rios , Estações do Ano , Astronave
6.
Zoolog Sci ; 36(6): 490-503, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31833320

RESUMO

Understanding migration ecology of Eurasian wigeons (Mareca penelope) is crucial for effective population management, mitigating conflicts with human, and habitat conservation. The objectives of the present study were 1) to determine their migration patterns of Eurasian wigeons in the East Asian flyway, and 2) to identify the key breeding and stopover sites. From 2007 to 2016, a total of the 64 wigeons, which wintered in Japan, were equipped with satellite transmitters. Most Eurasian wigeons migrated to breeding sites in Russia either (a) via a continental route through China, (b) via the Kamchatka Peninsula, or (c) via Sakhalin Island. In spring, many of the Eurasian wigeons (60.98%) migrated via the continental route. In autumn, most Eurasian wigeons (57.14%) migrated through Kamchatka. These differences may be attributable to the influence of Okhotsk Sea air mass on migration decisions due to loop migration. Similarly to the migration of Mallards, Eurasian wigeons employed a "long-stay and short-travel" migration strategy. Eurasian wigeons mainly nested between latitude between 43° to 75°N. From the present findings and the published literature, Eurasian wigeons that winter in Japan are considered to migrate to Russia, China, and the United States during the breeding season, although the main breeding area is in northeastern Russia. A total of 296 important sites to Eurasian wigeons were mapped, and 118 location names with geographic coordinates, and the top five most frequently used sites were identified in each season.


Assuntos
Sistemas de Identificação Animal , Migração Animal , Anseriformes/fisiologia , Estações do Ano , Astronave , Animais , China , Japão , Federação Russa
8.
Environ Pollut ; 255(Pt 2): 113267, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31574391

RESUMO

In recent years, ozone pollution has become more and more serious in China. Several epidemiological studies have demonstrated the correlation between short-term ozone exposure and several health risks including all-cause mortality, cardiovascular mortality, and respiratory mortality. In this study, the daily ozone exposure levels with 10 km × 10 km resolution were estimated based on satellite data derived from Ozone Monitoring Instrument (OMI) and the monitoring data. The health impacts for potential decrease in the daily ozone concentration and the corresponding economic benefits in 2016 were estimated by applying the environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) model. By reducing the daily maximum 8-h average concentration of ozone to 100 µg/m3, the estimated avoided all-cause mortalities were 120 × 103 (95% confidence interval (CI): 67 × 103, 160 × 103) cases and the correspondingly economic benefits ranged from 36 to 64 billion CNY using amended human capital (AHC) and willingness to pay (WTP) method in 2016. If the daily maximum 8-h average concentration of ozone were rolled back to 70 µg/m3, the estimated avoided all-cause mortalities were 160 × 103 (95% CI: 98 × 103, 230 × 103) cases and economic benefits ranged from 54 to 95 billion CNY based on AHC and WTP methods.


Assuntos
Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Tecnologia de Sensoriamento Remoto , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Exposição Ambiental/análise , Humanos , Modelos Teóricos , Ozônio/análise , Astronave
9.
Environ Pollut ; 255(Pt 1): 113106, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31541826

RESUMO

Satellite observations for regional air quality assessment rely on comprehensive spatial coverage, and daily monitoring with reliable, cloud-free data quality. We investigated spatiotemporal variation and data quality of two global satellite Aerosol Optical Depth (AOD) products derived from MODIS and VIIRS imagery. AOD is considered an essential atmospheric parameter strongly related to ground Particulate Matter (PM) in Southeast Asia (SEA). We analyze seasonal variation, urban/rural area influence, and biomass burning effects on atmospheric pollution. Validation indicated a strong relationship between AERONET ground AOD and both MODIS AOD (R2 = 0.81) and VIIRS AOD (R2 = 0.68). The monthly variation of satellite AOD and AERONET AOD reflects two seasonal trends of air quality separately for mainland countries including Myanmar, Laos, Cambodia, Thailand, Vietnam, and Taiwan, Hong Kong, and for maritime countries consisting of Indonesia, Philippines, Malaysia, Brunei, Singapore, and Timor Leste. The mainland SEA has a pattern of monthly AOD variation in which AODs peak in March/April, decreasing during wet season from May-September, and increasing to the second peak in October. However, in maritime SEA, AOD concentration peaks in October. The three countries with the highest annual satellite AODs are Singapore, Hong Kong, and Vietnam. High urban population proportions in Singapore (40.7%) and Hong Kong (21.6%) were associated with high AOD concentrations as expected. AOD values in SEA urban areas were a factor of 1.4 higher than in rural areas, with respective averages of 0.477 and 0.336. The AOD values varied proportionately to the frequency of biomass burning in which both active fires and AOD peak in March/April and September/October. Peak AOD in September/October in some countries could be related to pollutant transport of Indonesia forest fires. This study analyzed satellite aerosol product quality in relation to AERONET in SEA countries and highlighted framework of air quality assessment over a large, complicated region.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Análise Espaço-Temporal , Poluição do Ar/análise , Ásia Sudeste , Biomassa , Fogo , Estações do Ano , Astronave , Urbanização , Incêndios Florestais
10.
Life Sci Space Res (Amst) ; 22: 1-7, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31421843

RESUMO

After successfully launching two space laboratories, namely, Tiangong-1 and Tiangong-2, China has announced her next plan of constructing the Chinese Space Station (CSS) in 2022. The CSS will provide not only platforms for Chinese scientists to carry out experimental studies in outer space but also opportunities for open international cooperation. In this article, we review the development of China's manned space exploration missions and the preliminary plan for CSS. Additionally, China has initiated space radiation research decades ago with both ground-based simulation research platform and space vehicles and has made noticeable progresses in several aspects. These include studies on human health risk assessment using mammalian cell cultures and animals as models. Furthermore, there have been numerous studies on assessing the space environment in plant breeding.


Assuntos
Voo Espacial , Animais , China , Células Eucarióticas/fisiologia , Células Eucarióticas/efeitos da radiação , Humanos , Laboratórios , Mamíferos , Mutagênese , Desenvolvimento Vegetal , Plantas/efeitos da radiação , Radiobiologia/métodos , Medição de Risco , Astronave
11.
Life Sci Space Res (Amst) ; 22: 38-46, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31421847

RESUMO

The object play behavior in thick-toed geckos (Chondrodactylus turneri GRAY 1864) was studied during a 30-day orbital experiment onboard the Bion-M1 biosatellite. The play object for five geckos was a marking collar that one of the geckos in the flight group removed immediately before the launch. The play behavior started when either the gecko observed the approaching floating collar or when the gecko independently approached the stationary collar, followed by manipulation of the collar and subsequent observation of its moving away. While playing with the collar, the individuality of geckos' behavior was manifested in the frequency and number of play episodes, the nature of manipulations, and the duration of interest in play during the flight. We found that thick-toed geckos could play not only with an unknown object (marking collar) but also with familiar molting skins. In weightlessness, the play behavior of geckos with molting skin fragments was similar to the play behavior with the collar and also varied between individuals. It was established that geckos maintained a similar individual level of play activity with different objects (collar and molting skins). It was found that geckos also played with fragments of molting skin under normal gravity conditions. In contrast to weightlessness, play behavior at normal gravity was rare and limited to short durations of object manipulation.


Assuntos
Lagartos/fisiologia , Voo Espacial , Ausência de Peso , Adaptação Fisiológica , Animais , Comportamento Animal , Feminino , Astronave , Gravação em Vídeo
12.
Life Sci Space Res (Amst) ; 22: 68-75, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31421850

RESUMO

The nutrient delivery system is one of the most important hardware components in tomato (Lycopersicon esculentum Mill.) production in Bio-regenerative Life Support Systems (BLSS) for future long-term space mission. The objective of this study was to investigate the influences of different nutrient delivery systems (aeroponics, hydroponics and porous tube-vermiculite) on the growth, photosynthetic characteristics, antioxidant capacity, biomass yield and quality of tomato during its life cycle. The results showed that the dry weight of aeroponics and porous tube-vermiculite treatment group was 1.95 and 1.93 g/fruit, but the value of hydroponics treatment group was only 1.56 g/fruit. Both tomato photosynthesis and stomatal conductance maximized at the development stage and then decreased later in senescent leaves. At the initial stage and the development stage, POD activities in the aeroponics treatment were higher than other two treatments, reached 3.6 U/mg prot and 4.6 U/mg prot, respectively. The fresh yield 431.3 g/plant of hydroponics treatment group was lower. At the same time, there were no significant differences among nutrient delivery systems in the per fruit fresh mass, which was 14.2-17.5 g/fruit.


Assuntos
Sistemas Ecológicos Fechados , Lycopersicon esculentum/crescimento & desenvolvimento , Biomassa , Hidroponia , Lycopersicon esculentum/química , Fotossíntese , Astronave
13.
Life Sci Space Res (Amst) ; 22: 98-124, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31421854

RESUMO

The space radiation environment is a complex mixture of particle types and energies originating from sources inside and outside of the galaxy. These environments may be modified by the heliospheric and geomagnetic conditions as well as planetary bodies and vehicle or habitat mass shielding. In low Earth orbit (LEO), the geomagnetic field deflects a portion of the galactic cosmic rays (GCR) and all but the most intense solar particle events (SPE). There are also dynamic belts of trapped electrons and protons with low to medium energy and intense particle count rates. In deep space, the GCR exposure is more severe than in LEO and varies inversely with solar activity. Unpredictable solar storms also present an acute risk to astronauts if adequate shielding is not provided. Near planetary surfaces such as the Earth, moon or Mars, secondary particles are produced when the ambient deep space radiation environment interacts with these surfaces and/or atmospheres. These secondary particles further complicate the local radiation environment and modify the associated health risks. Characterizing the radiation fields in this vast array of scenarios and environments is a challenging task and is currently accomplished with a combination of computational models and dosimetry. The computational tools include models for the ambient space radiation environment, mass shielding geometry, and atomic and nuclear interaction parameters. These models are then coupled to a radiation transport code to describe the radiation field at the location of interest within a vehicle or habitat. Many new advances in these models have been made in the last decade, and the present review article focuses on the progress and contributions made by workers and collaborators at NASA Langley Research Center in the same time frame. Although great progress has been made, and models continue to improve, significant gaps remain and are discussed in the context of planned future missions. Of particular interest is the juxtaposition of various review committee findings regarding the accuracy and gaps of combined space radiation environment, physics, and transport models with the progress achieved over the past decade. While current models are now fully capable of characterizing radiation environments in the broad range of forecasted mission scenarios, it should be remembered that uncertainties still remain and need to be addressed.


Assuntos
Radiação Cósmica , Modelos Teóricos , Astronautas , Humanos , Física Nuclear , Atividade Solar , Voo Espacial , Astronave , Estados Unidos , United States National Aeronautics and Space Administration
14.
Appl Microbiol Biotechnol ; 103(18): 7767-7782, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31388730

RESUMO

Exposure to bioaerosols can adversely influence human health through respiratory tract, eye, and skin irritation. Bioaerosol composition is unique on the International Space Station (ISS), where the size distribution of particles in the air differs from those on Earth. This is due to the lack of gravitational settling and sources of biological particles. However, we do not understand how microbes are influenced by particle size in this environment. We analyzed two types of samples from the ISS: (1) vacuum bag debris which had been sieved into five different size fractions and (2) passively collected particles on a tape substrate with a passive aerosol sampler. Using quantitative polymerase chain reaction (qPCR), the highest concentration of fungal spores was found in the 106-150 µm-sized sieved dust particles, while the highest concentration of bacterial cells was found in the 150-250 µm-sized sieved dust particles. Illumina MiSeq DNA sequencing revealed that particle size was associated with bacterial and fungal communities and statistically significant (p = 0.035, p = 0.036 respectively). Similar fungal and bacterial species were found within the passive aerosol sample and the sieved dust samples. The most abundant fungal species identified in the aerosol and sieved samples are commonly found in food and plant material. Abundant bacterial species were most associated with the oral microbiome and human upper respiratory tract. One limitation to this study was the suboptimal storage conditions of the sieved samples prior to analysis. Overall, our results indicate that microbial exposure in space may depend on particle size. This has implications for ventilation and filtration system design for future space vehicles and habitats.


Assuntos
Aerossóis/análise , Microbiologia do Ar , Poeira/análise , Microbiota , Tamanho da Partícula , Astronave , Bactérias/genética , Bactérias/isolamento & purificação , Monitoramento Ambiental , Humanos , Internacionalidade , Sistema Respiratório/microbiologia , Análise de Sequência de DNA , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação
15.
Mar Pollut Bull ; 146: 683-695, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426210

RESUMO

The Eastern Arabian Sea (EAS) is affected by oil pollution, as often evidenced by the presence of tarballs along the West Coast of India (WCI). Tarball samples collected during May 2017 along the Goa coast were subject to biomarker fingerprints, and the results matched with Bombay High (BH) oil fingerprints. The present study primarily aims at identifying the potential minor spill areas using Sentinel-imagery. Interestingly, repeated occurrence of oil spills detected at two locations, perfectly matched with BH platforms. The simulated Lagrangian trajectories also depict that tarball particles have originated from those detected locations. In 2017 alone, the quantity of spilled oil was estimated to be 129,392 l. However, spills detected offshore regions of Kachchh and Mangalore were found to be caused by ships. This is the first comprehensive study, tracking the oil pollution sources in the EAS through multi-technique approach - chemical, remote sensing and numerical modeling.


Assuntos
Monitoramento Ambiental/métodos , Poluição por Petróleo/análise , Poluição Química da Água/análise , Índia , Petróleo/análise , Tecnologia de Sensoriamento Remoto/métodos , Navios , Astronave , Triterpenos/análise , Poluentes Químicos da Água/análise
16.
Aerosp Med Hum Perform ; 90(9): 807-812, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31426897

RESUMO

INTRODUCTION: The previous Spacecraft Maximal Allowable Concentrations (SMACs) for methanol were established by characterizing minor effects upon cognitive functions as a no-observable adverse effects level (NOAEL). However, an increasing awareness of the risk posed by Space-Associated Neuro-ocular Syndrome (SANS) has caused NASA Toxicology to reexamine SMACs for methanol because exposure to it can also adversely affect ocular health. An updated review of the literature indicates that no adjustments to the SMACs due to SANS complications were required, while confirming that effects upon the central nervous system remain the appropriate basis for the SMACs for methanol. Our review, however, identified several issues that provide justification for modest SMAC reductions. It has recently been recognized that inhaled methanol may reach the brain via the olfactory system and be absorbed there into the highly toxic metabolite formaldehyde. A benchmark dose (BMD) for an extra risk of 10%, derived from an analysis of the incidences of neurological lesions in monkeys chronically exposed to methanol, is an order of magnitude less than the Environmental Protection Agency's (EPA's) reference concentration for chronic inhalation of methanol. Reports calling attention to the relative insensitivity of traditional methods of assessing cognitive function erode confidence that adverse effects at the concentration reported as a NOAEL would have been recognizable. Therefore, an additional modest safety factor of three is applied to SMACs for methanol.Scully RR, Garcia H, McCoy JT, Ryder VE. Revisions to limits for methanol in the air of spacecraft. Aerosp Med Hum Perform. 2019; 90(9):807-812.


Assuntos
Cognição/efeitos dos fármacos , Metanol/toxicidade , Síndromes Neurotóxicas/prevenção & controle , Astronave/normas , Níveis Máximos Permitidos , Animais , Astronautas , Modelos Animais de Doenças , Haplorrinos , Humanos , Incidência , Concentração Máxima Permitida , Síndromes Neurotóxicas/epidemiologia , Síndromes Neurotóxicas/etiologia , Nível de Efeito Adverso não Observado , Exposição Ocupacional/normas , Testes de Toxicidade Crônica
17.
PLoS One ; 14(8): e0205862, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31461452

RESUMO

Translocated saltwater crocodiles (Crocodylus porosus) in the Northern Territory (NT) of Australia often return to their original capture sites, which complicates management interventions aimed at reducing human-crocodile conflict. We examined the spatial events implicated in this homing ability, using ARGOS satellite tracking devices. Five large male C. porosus (3.03 m to 4.02 m TL) were shifted and released 100-320 km from their capture sites, and 3 additional ones (3.67 m to 4.23 m TL) were released at their site of capture as controls. Translocated crocodiles were more mobile than the controls, and moved at sea in the direction of their original capture site. However, they were unable or unwilling to swim around a geographic structure, Cobourg Peninsula, which prevented homing being achieved in all five cases. Two control crocodiles remained near their capture sites, but one, after the first year, made a 900km journey for six months, before returning to its original capture and release site. Genetic analysis of tissue samples from nests across the NT coast demonstrated significant genetic structure across the coast, and confirmed that Cobourg Peninsula contributes to genetic differentiation among populations along the NT coast. These results provide new insights into C. porosus movements, which have management significance for the maintenance of public safety.


Assuntos
Jacarés e Crocodilos/genética , Jacarés e Crocodilos/fisiologia , Distribuição Animal , Geografia , Comportamento de Retorno ao Território Vital , Movimento , Animais , Estruturas Genéticas , Masculino , Astronave
18.
Sci Total Environ ; 689: 808-819, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31280163

RESUMO

The aim of this study is to investigate the impact of ten proposed plants along with three operating plants in Çanakkale province of Turkey where the proposed plants are within very close proximity. The province has the highest capacity of the planned plants and the region is also of interest due to its history, tourism and agriculture potential. Current SO2 pollution was assessed using ground observations and satellite retrievals where the impact of plants was better captured by satellite retrievals. Individual and cumulative impact from proposed and operating plants was simulated by CALPUFF for 2014. The study domain was 150 × 150 km2, with 1 × 1 km2 cell size. The effect of changing meteorological inputs and domain size were investigated with simulations. Three cases were performed using meteorological inputs: from one surface and one radiosonde station (Case 1), 22 surface and one radiosonde station (Case 2), and 22 surface and two radiosonde stations (Case 3). Case 2 and 3 resulted in higher concentrations and showed larger affected regions than case 1 in all simulations. The cumulative impact of proposed plants indicated national annual and daily limit values were exceeded in Case 2 and 3. Hourly limit values were exceeded in all three cases. Simulations for two selected proposed plants were assessed for plant impact area given in environmental impact area reports. Results indicated the plant impact areas cannot be sufficient to determine the maximum SO2 concentrations in some cases and using single meteorology station data cannot represent the study area, especially regions with complex terrain and land-sea interactions such as Çanakkale province. Cumulative impact can be underestimated due to small size of plant impact areas not including other plants. Lastly satellite retrievals are better capturing the pollution than air quality monitoring stations which are strongly affected by meteorology.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Centrais Elétricas , Tecnologia de Sensoriamento Remoto , Dióxido de Enxofre/análise , Carvão Mineral , Modelos Teóricos , Astronave
19.
Sensors (Basel) ; 19(13)2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31288380

RESUMO

Measuring chlorophyll fluorescence is a direct and non-destructive way to monitor vegetation. In this paper, the fluorescence retrieval methods from multiple scales, ranging from near the ground to the use of space-borne sensors, are analyzed and summarized in detail. At the leaf-scale, the chlorophyll fluorescence is measured using active and passive technology. Active remote sensing technology uses a fluorimeter to measure the chlorophyll fluorescence, and passive remote sensing technology mainly depends on the sun-induced chlorophyll fluorescence filling in the Fraunhofer lines or oxygen absorptions bands. Based on these retrieval principles, many retrieval methods have been developed, including the radiance-based methods and the reflectance-based methods near the ground, as well as physically and statistically-based methods that make use of satellite data. The advantages and disadvantages of different approaches for sun-induced chlorophyll fluorescence retrieval are compared and the key issues of the current sun-induced chlorophyll fluorescence retrieval algorithms are discussed. Finally, conclusions and key problems are proposed for the future research.


Assuntos
Algoritmos , Clorofila/análise , Modelos Teóricos , Tecnologia de Sensoriamento Remoto/métodos , Atmosfera , Fluorescência , Modelos Estatísticos , Folhas de Planta/química , Astronave , Espectrofotometria/métodos
20.
Aerosp Med Hum Perform ; 90(8): 709-719, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31331421

RESUMO

INTRODUCTION: Exposure to excess manganese (Mn) can cause multiple toxicological outcomes in humans, most notably neurotoxicity. Ample epidemiological evidence suggests that chronic, low-level exposure causes subclinical cognitive effects. Because NASA astronauts will be exposed to Mars regolith, Spacecraft Maximum Allowable Concentrations (SMACs) were developed following an extensive literature review.METHODS: Multiple databases were searched for information relevant to derivation of Mn SMAC values. An additional search for Mars dust data was performed. Risk assessment approaches were applied, including adjustments for space-relevant susceptibility to Mn effects, to develop limits for 1-h to 1000-d exposures. Rover data informed the assessment and enabled calculation of allowable total dust exposure based on Mn content.RESULTS: Over 400 relevant sources were identified. Applicability of exposure characteristics and data collection methods influenced key study choice. SMACs ranging from 3 mg · m-3 (1 h) - 0.0079 mg · m-3 (1000 d) were set to protect primarily against neurocognitive and respiratory effects. Considering 0.38 wt% total Mn presence in the dust, maximum recommended total dust exposure should not exceed 790 mg · m-3 (1 h) - 2 mg · m-3 (1000 d).DISCUSSION: This literature review allowed for identification of relevant studies to inform SMAC development. Manganese is one of several components to consider when developing an appropriate total dust limit for Martian dust; other dust elements may alter Mn bioavailability. Mission-specific activities may require alteration of assumptions regarding Mn dust concentration and exposure duration. However, based on expected toxicity of particulate matter itself, the acute SMACs are protective, even with transient exposure during activities that could produce higher concentrations.Romoser AA, Ryder VE, McCoy JT. Spacecraft maximum allowable concentrations for manganese compounds in Mars dust. Aerosp Med Hum Perform. 2019; 90(8):709-719.


Assuntos
Poluentes Ocupacionais do Ar/efeitos adversos , Poeira Cósmica , Compostos de Manganês , Exposição Ocupacional/efeitos adversos , Astronave , Humanos , Marte , Concentração Máxima Permitida , Medição de Risco
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