Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.165
Filtrar
1.
Aerosp Med Hum Perform ; 92(2): 106-112, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33468291

RESUMO

BACKGROUND: Limited research exists into extraterrestrial CPR, despite the drive for interplanetary travel. This study investigated whether the terrestrial CPR method can provide quality external chest compressions (ECCs) in line with the 2015 UK resuscitation guidelines during ground-based hypogravity simulation. It also explored whether gender, weight, and fatigue influence CPR quality.METHODS: There were 21 subjects who performed continuous ECCs for 5 min during ground-based hypogravity simulations of Mars (0.38 G) and the Moon (0.16 G), with Earths gravity (1 G) as the control. Subjects were unloaded using a body suspension device (BSD). ECC depth and rate, heart rate (HR), ventilation (VE), oxygen uptake (Vo2), and Borg scores were measured.RESULTS: ECC depth was lower in 0.38 G (42.9 9 mm) and 0.16 G (40.8 9 mm) compared to 1 G and did not meet current resuscitation guidelines. ECC rate was adequate in all gravity conditions. There were no differences in ECC depth and rate when comparing gender or weight. ECC depth trend showed a decrease by min 5 in 0.38 G and by min 2 in 0.16 G. Increases in HR, VE, and Vo2 were observed from CPR min 1 to min 5.DISCUSSION: The terrestrial method of CPR provides a consistent ECC rate but does not provide adequate ECC depths in simulated hypogravities. The results suggest that a mixed-gender space crew of varying bodyweights may not influence ECC quality. Extraterrestrial-specific CPR guidelines are warranted. With a move to increasing ECC rate, permitting lower ECC depths and substituting rescuers after 1 min in lunar gravity and 4 min in Martian gravity is recommended.Sriharan S, Kay G, Lee JCY, Pollock RD, Russomano T. Cardiopulmonary resuscitation in hypogravity simulation. Aerosp Med Hum Perform. 2021; 92(2):106112.


Assuntos
Reanimação Cardiopulmonar/métodos , Meio Ambiente Extraterreno , Hipogravidade , Adulto , Feminino , Humanos , Masculino , Treinamento por Simulação
3.
Adv Genet ; 106: 1-4, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33081918

RESUMO

This current volume is, in many ways, a 2020 update to the important 1999-2000 compendium by Sir Fred Hoyle and Professor N. Chandra Wickramasinghe's "Astronomical Origins of life: Steps towards Panspermia." The emerging new paradigm of biology that connects life on Earth with the wider cosmos is covered in considerable depth showing that terrestrial biological evolution is best understood as a cosmically derived habitat and an interconnected genetic system. The various chapters here discuss all aspects of this interconnectedness, particularly relevant now in this time of the coronavirus pandemic (COVID-19) as the human race reacts to the many microbes and viral pathogens that arrive regularly from space.


Assuntos
Evolução Biológica , Meio Ambiente , Exobiologia , Interações Hospedeiro-Patógeno/fisiologia , Betacoronavirus/fisiologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Doença/etiologia , Ecossistema , Meio Ambiente Extraterreno , Humanos , Modelos Biológicos , Origem da Vida , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia
4.
Adv Genet ; 106: 75-100, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33081928

RESUMO

The origins and global spread of two recent, yet quite different, pandemic diseases is discussed and reviewed in depth: Candida auris, a eukaryotic fungal disease, and COVID-19 (SARS-CoV-2), a positive strand RNA viral respiratory disease. Both these diseases display highly distinctive patterns of sudden emergence and global spread, which are not easy to understand by conventional epidemiological analysis based on simple infection-driven human- to-human spread of an infectious disease (assumed to jump suddenly and thus genetically, from an animal reservoir). Both these enigmatic diseases make sense however under a Panspermia in-fall model and the evidence consistent with such a model is critically reviewed.


Assuntos
Evolução Biológica , Candidíase/etiologia , Doenças Transmissíveis Emergentes/etiologia , Infecções por Coronavirus/etiologia , Origem da Vida , Pneumonia Viral/etiologia , Animais , Betacoronavirus/isolamento & purificação , Betacoronavirus/fisiologia , Candida/isolamento & purificação , Candida/fisiologia , Candidíase/epidemiologia , Doenças Transmissíveis Emergentes/epidemiologia , Coronavirus/isolamento & purificação , Coronavirus/fisiologia , Infecções por Coronavirus/epidemiologia , Planeta Terra , Exobiologia , Meio Ambiente Extraterreno , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Pandemias , Pneumonia Viral/epidemiologia
6.
PLoS One ; 15(9): e0238606, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32936806

RESUMO

Given plans to revisit the lunar surface by the late 2020s and to take a crewed mission to Mars by the late 2030s, critical technologies must mature. In missions of extended duration, in situ resource utilization is necessary to both maximize scientific returns and minimize costs. While this present a significantly more complex challenge in the resource-starved environment of Mars, it is similar to the increasing need to develop resource-efficient and zero-waste ecosystems on Earth. Here, we make use of recent advances in the field of bioinspired chitinous manufacturing to develop a manufacturing technology to be used within the context of a minimal, artificial ecosystem that supports humans in a Martian environment.


Assuntos
Quitina/química , Exobiologia , Meio Ambiente Extraterreno , Marte
8.
Proc Natl Acad Sci U S A ; 117(35): 21008-21010, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817482

RESUMO

The Late Devonian was a protracted period of low speciation resulting in biodiversity decline, culminating in extinction events near the Devonian-Carboniferous boundary. Recent evidence indicates that the final extinction event may have coincided with a dramatic drop in stratospheric ozone, possibly due to a global temperature rise. Here we study an alternative possible cause for the postulated ozone drop: a nearby supernova explosion that could inflict damage by accelerating cosmic rays that can deliver ionizing radiation for up to [Formula: see text] ky. We therefore propose that the end-Devonian extinctions were triggered by supernova explosions at [Formula: see text], somewhat beyond the "kill distance" that would have precipitated a full mass extinction. Such nearby supernovae are likely due to core collapses of massive stars; these are concentrated in the thin Galactic disk where the Sun resides. Detecting either of the long-lived radioisotopes [Formula: see text] or [Formula: see text] in one or more end-Devonian extinction strata would confirm a supernova origin, point to the core-collapse explosion of a massive star, and probe supernova nucleosynthesis. Other possible tests of the supernova hypothesis are discussed.


Assuntos
Radiação Cósmica/efeitos adversos , Extinção Biológica , Fósseis/história , Biodiversidade , Meio Ambiente Extraterreno/química , História Antiga , Astros Celestes
9.
Proc Natl Acad Sci U S A ; 117(35): 21031-21036, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817511

RESUMO

One of the major goals for astronomy in the next decades is the remote search for biosignatures (i.e., the spectroscopic evidence of biological activity) in exoplanets. Here we adopt a Bayesian statistical framework to discuss the implications of such future searches, both in the case when life is detected and when no definite evidence is found. We show that even a single detection of biosignatures in the vicinity of our stellar system, in a survey of similar size to what will be obtainable in the next 2 decades, would affect significantly our prior belief on the frequency of life in the universe, even starting from a neutral or pessimistic stance. In particular, after such discovery, an initially agnostic observer would be led to conclude that there are more than [Formula: see text] inhabited planets in the galaxy with a probability exceeding 95%. However, this conclusion would be somewhat weakened by the viability of transfer of biological material over interstellar distances, as in panspermia scenarios. Conversely, the lack of significant evidence of biosignatures would have little effect, leaving the assessment of the abundance of life in the galaxy still largely undetermined.


Assuntos
Exobiologia/métodos , Análise Espectral/métodos , Astronomia , Teorema de Bayes , Meio Ambiente Extraterreno , Galáxias , Origem da Vida , Planetas
10.
Proc Natl Acad Sci U S A ; 117(30): 17482-17490, 2020 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-32641501

RESUMO

Historically, many biologists assumed that evolution and ecology acted independently because evolution occurred over distances too great to influence most ecological patterns. Today, evidence indicates that evolution can operate over a range of spatial scales, including fine spatial scales. Thus, evolutionary divergence across space might frequently interact with the mechanisms that also determine spatial ecological patterns. Here, we synthesize insights from 500 eco-evolutionary studies and develop a predictive framework that seeks to understand whether and when evolution amplifies, dampens, or creates ecological patterns. We demonstrate that local adaptation can alter everything from spatial variation in population abundances to ecosystem properties. We uncover 14 mechanisms that can mediate the outcome of evolution on spatial ecological patterns. Sometimes, evolution amplifies environmental variation, especially when selection enhances resource uptake or patch selection. The local evolution of foundation or keystone species can create ecological patterns where none existed originally. However, most often, we find that evolution dampens existing environmental gradients, because local adaptation evens out fitness across environments and thus counteracts the variation in associated ecological patterns. Consequently, evolution generally smooths out the underlying heterogeneity in nature, making the world appear less ragged than it would be in the absence of evolution. We end by highlighting the future research needed to inform a fully integrated and predictive biology that accounts for eco-evolutionary interactions in both space and time.


Assuntos
Evolução Biológica , Ecossistema , Meio Ambiente Extraterreno , Biodiversidade , Biomassa , Nutrientes , Dinâmica Populacional
12.
Sci Rep ; 10(1): 10941, 2020 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-32616785

RESUMO

The transition of the martian climate from the wet Noachian era to the dry Hesperian (4.1-3.0 Gya) likely resulted in saline surface waters that were rich in sulfur species. Terrestrial analogue environments that possess a similar chemistry to these proposed waters can be used to develop an understanding of the diversity of microorganisms that could have persisted on Mars under such conditions. Here, we report on the chemistry and microbial community of the highly reducing sediment of Colour Peak springs, a sulfidic and saline spring system located within the Canadian High Arctic. DNA and cDNA 16S rRNA gene profiling demonstrated that the microbial community was dominated by sulfur oxidising bacteria, suggesting that primary production in the sediment was driven by chemolithoautotrophic sulfur oxidation. It is possible that the sulfur oxidising bacteria also supported the persistence of the additional taxa. Gibbs energy values calculated for the brines, based on the chemistry of Gale crater, suggested that the oxidation of reduced sulfur species was an energetically viable metabolism for life on early Mars.


Assuntos
Bactérias/classificação , Bactérias/genética , Biodiversidade , DNA Bacteriano/genética , Sedimentos Geológicos/análise , Marte , Enxofre/química , Bactérias/metabolismo , DNA Ribossômico/genética , Meio Ambiente Extraterreno , Filogenia , RNA Ribossômico 16S , Enxofre/metabolismo
13.
Nat Commun ; 11(1): 2731, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32518292

RESUMO

Identification of habitable planets beyond our solar system is a key goal of current and future space missions. Yet habitability depends not only on the stellar irradiance, but equally on constituent parts of the planetary atmosphere. Here we show, for the first time, that radiatively active mineral dust will have a significant impact on the habitability of Earth-like exoplanets. On tidally-locked planets, dust cools the day-side and warms the night-side, significantly widening the habitable zone. Independent of orbital configuration, we suggest that airborne dust can postpone planetary water loss at the inner edge of the habitable zone, through a feedback involving decreasing ocean coverage and increased dust loading. The inclusion of dust significantly obscures key biomarker gases (e.g. ozone, methane) in simulated transmission spectra, implying an important influence on the interpretation of observations. We demonstrate that future observational and theoretical studies of terrestrial exoplanets must consider the effect of dust.


Assuntos
Biomarcadores/análise , Poeira/análise , Exobiologia , Meio Ambiente Extraterreno , Minerais/análise , Planetas , Atmosfera , Clima , Simulação por Computador , Temperatura
15.
J Vis Exp ; (159)2020 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-32449704

RESUMO

Spatially resolving exoplanet features from single-point observations is essential for evaluating the potential habitability of exoplanets. The ultimate goal of this protocol is to determine whether these planetary worlds harbor geological features and/or climate systems. We present a method of extracting information from multi-wavelength single-point light curves and retrieving surface maps. It uses singular value decomposition (SVD) to separate sources that contribute to light curve variations and infer the existence of partially cloudy climate systems. Through analysis of the time series obtained from SVD, physical attributions of principal components (PCs) could be inferred without assumptions of any spectral properties. Combining with viewing geometry, it is feasible to reconstruct surface maps if one of the PCs are found to contain surface information. Degeneracy originated from convolution of the pixel geometry and spectrum information determines the quality of reconstructed surface maps, which requires the introduction of regularization. For the purpose of demonstrating the protocol, multi-wavelength light curves of Earth, which serves as a proxy exoplanet, are analyzed. Comparison between the results and the ground truth is presented to show the performance and limitation of the protocol. This work provides a benchmark for future generalization of exoplanet applications.


Assuntos
Planeta Terra , Exobiologia/métodos , Meio Ambiente Extraterreno , Luz , Planetas , Processamento de Imagem Assistida por Computador , Fatores de Tempo
16.
Health Secur ; 18(2): 132-138, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32324071

RESUMO

The normal scope of an adequate public health response to released biological material is framed by working with biological vectors with known pathogenicity and virulence. Defining the scope of a response to the release of biological material with unknown pathogenicity and virulence enters into a novel and yet to be framed domain. A current case, in which extraterrestrial samples returned from a location such as Mars, which may harbor life as we know it, requires framing a public health response. An unintentional release of biological material with unknown pathogenicity and virulence may occur when biological containment mechanisms in the Earth-returning transport method are lost. This article raises initial public health and healthcare response questions during a return of extraterrestrial samples to Earth, in the event of its release from biological containment mechanisms: How does the public health community prepare for a response when there is release of samples that may contain potential extraterrestrial organisms from a planetary body or hardy terrestrial organisms surviving a round trip? If a mishap occurs during the return of these samples, what considerations need to be made to confine, decontaminate, and collect material in regions around the mishap? How will the public health community work with relevant government organizations to prepare the general public? The unknowns of exposure, potential extraterrestrial pathogenicity, and decontamination approaches underscore gaps in biopreparedness for this novel case from federal to local levels.


Assuntos
Contenção de Riscos Biológicos/métodos , Descontaminação/métodos , Exobiologia , Meio Ambiente Extraterreno , Contenção de Riscos Biológicos/normas , Descontaminação/normas , Planeta Terra , Contaminação de Equipamentos/prevenção & controle , Humanos , Astronave
17.
Med Sci (Paris) ; 36(3): 264-270, 2020 Mar.
Artigo em Francês | MEDLINE | ID: mdl-32228846

RESUMO

Star Wars, a "general public" film saga, raises questions about human nature and transhumanism. It features different characters who are neither "real" humans nor robots; there are creatures that can be likened to advanced humans (cyborgs, chimeras or genetically-modified humans). Based on the "Star Wars" movie, we will approach some ways of modifying the human person both in his body and in his consciousness and we will wonder about the man of tomorrow by asking ourselves if George Lucas (director of the first film released) might have not been a visionary of the men of tomorrow.


Assuntos
Pessoas Famosas , Obras de Ficção como Assunto , Humanismo , Filmes Cinematográficos , Ciência nas Artes , Animais , California , Meio Ambiente Extraterreno , Melhoramento Genético , História do Século XX , História do Século XXI , Características Humanas , Humanismo/história , Humanos , Camundongos , Filmes Cinematográficos/história , Filosofia , Ciência nas Artes/história , Pesquisa com Células-Tronco/história
19.
Health Phys ; 118(4): 335-348, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32118678

RESUMO

The National Council on Radiation Protection and Measurements (NCRP) held its 55 Annual Meeting 1-2 April 2019 in Bethesda, Maryland. The 2019 meeting was a special year for NCRP as it marked the 90 Anniversary of the founding of the predecessor organization, US Advisory Committee on X-Ray and Radium Protection. Leaders for the scientific portion of the meeting were Fred A. Mettler, Jr., M.D. (Chair), University of New Mexico School of Medicine; Jerrold T. Bushberg, Ph.D. (Co-Chair), University of California Davis; and Richard J. Vetter, Ph.D. (Co-Chair), Mayo Clinic. The meeting was designed to explore important areas of inquiry associated with use of ionizing radiation relevant to radiation protection, addressing frequently asked questions and concerns from both members of the public and radiation professionals. The meeting was organized into six sessions plus three honorary lectures and a special presentation. This paper summarizes the scientific content of the six sessions and is based on the notes of the co-chairs and the slides of the speakers. The three honorary lectures are included as other papers in this issue.


Assuntos
Monitoramento de Radiação , Proteção Radiológica , Sociedades Científicas , Meio Ambiente Extraterreno , Humanos , Doses de Radiação , Resíduos Radioativos , Risco
20.
Rev. med. cine ; 16(1): 29-36, mar. 2020. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-197592

RESUMO

El cine de Ciencia-Ficción se ha convertido en un muestrario de los últimos avances tecnológicos y de la vanguardia y especulación científica. Puede, por ello, ser utilizado como herramienta de divulgación y como recurso formativo. Sin embargo, si se quiere diferenciar lo real y plausible de lo fantástico e imposible, se hace necesario tener una mirada rigurosa del material tecnocientífico que nos presenta. En el presente estudio se describe y analiza el contenido biomédico de las películas de la saga Alien. De las diferentes áreas de conocimiento catalogadas por el Ministerio de Educación, Cultura y Deporte de España, encontramos que al menos 37 de ellas, relacionadas con temas biosanitarios, se trataban con diferente profundidad en la saga, destacando especialmente la Microbiología y Parasitología Clínica o la Fisiología y Anatomía Humanas. Aun admitiendo las licencias artísticas del género fantástico al que pertece la saga, creemos que el contenido y tratamiento biomédico de estas obras podría ser utilizado como recurso docente para estudiantes de diferentes grados biosanitarios como Medicina, Enfermería, Farmacia u Odontología


The Science-Fiction movies have become a showcase of the latest technological advances and vanguard and scientific speculation. It can, therefore, be used as a divulgation tool and as a training resource. However, if you want to differentiate the real and plausible from the fantastic and impossible, it is necessary to have a rigorous look of the techno-scientific material that presents us. In the present study, the biomedical content of the films of the Alien saga is described and analyzed. Of the different areas of knowledge cataloged by the Ministry of Education, Culture and Sports of Spain, we found that at least 37 of them, related to biosanitary issues, were treated with different depth in the saga, highlighting especially the Microbiology and Clinical Parasitology or the Human Physiology and Anatomy. Even admitting the artistic licenses of the fantastic genre to which the saga belongs, we believe that the content and biomedical treatment of these works could be used as a teaching resource for students of different biosanitary degrees such as Medicine, Nursing, Pharmacy or Dentistry


Assuntos
Humanos , Exobiologia , Meio Ambiente Extraterreno , Filmes Cinematográficos , Parasitos , Interações Hospedeiro-Parasita
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA