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1.
Astrobiology ; 23(8): 888-896, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37222799

RESUMO

The Mars 2020 mission delivered the Perseverance rover to the surface of Mars using a supersonic parachute manufactured at Airborne Systems, California. The Mars 2020 spacecraft, including the flight parachute, was subject to Planetary Protection spore bioburden compliance. Many previous missions with similar parachutes applied manufacturing specifications for calculating bioburden. Although the Mars 2020 parachute was manufactured in an uncontrolled environment, preliminary sampling of a flight-like parachute manufactured in the same facility suggested that the actual spore bioburden levels were potentially orders of magnitude lower than specification values for uncontrolled manufacturing (100,000 spores/m2). Several experiments were designed and carried out throughout the project timeline in an effort to estimate a representative bioburden for the flight parachute. Tests were performed on various parachute materials, including direct sampling and destructive assays of proxy materials. Different bioburden densities were applied to large continuous areas of the canopy, which experienced minimal handling, and seamed areas of the parachute that were likely to experience more handling during the stitching process. In addition, an approach to account for various thermal zones was developed and applied toward calculating log reduction for the parachute assembly. These various methods that were used toward different areas and materials of the Mars 2020 flight parachute provided a nuanced and data-backed estimate of spore bioburden density that can be adopted by future missions.


Assuntos
Marte , Voo Espacial , Meio Ambiente Extraterreno , Astronave , Planetas , Esporos Bacterianos
2.
Front Microbiol ; 13: 909997, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35898903

RESUMO

The ever-increasing complexity in critical spacecraft hardware and materials has led to the development of new microbial reduction procedures as well as to changes in established processes such as heat microbial reduction (HMR). In the space biology field of Planetary Protection, 500°C for 0.5 s is the current HMR recommendation to reduce microorganisms from flight hardware. However, more studies are needed to effectively determine the microbial reduction capability of high-temperature (more than 200°C), short-duration (under 30 s) heat exposures. One of the many recent microbial reduction bioengineering research avenues harnesses electromagnetic energy for microbial reduction, with previous investigations demonstrating that infrared heaters are capable of the short temperature ramp time required for rapid heating investigations above 200°C. Therefore, this study employed a 6 kW infrared heater to determine the survivability of heat resistant Bacillus canaveralius 29669 to high-temperature, short-duration infrared temperatures. While B. canaveralius 29669 spores can survive microbial heat reduction processes above 200°C, we found evidence suggesting that the 500°C for 0.5 s temperature sterilization specification for Planetary Protection should be updated. This research presents spore survival data and a corresponding model pointing to a re-evaluation of the recommended HMR exposure of 500°C for 0.5 s, while simultaneously meeting requirements on the forward biological contamination of solar system bodies and opening up design possibilities for future spacecraft hardware.

3.
Astrobiology ; 22(S1): S238-S241, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34904891

RESUMO

The National Aeronautics and Space Administration-European Space Agency (NASA-ESA) Mars Sample Return (MSR) campaign involves the collection of samples on Mars by the Perseverance (Mars 2020) rover and their return to Earth. To accomplish this, the Orbiting Sample container (OS) will be sent to Mars to accommodate the collected samples then launched from Mars and returned to Earth, where the samples will be removed for examination in the Sample Return Facility (SRF). Crucial to this entire sequence will be establishment of the required level of cleanliness inside the OS. In February 2021, the NASA Headquarters' Mars Sample Return Program and Office of Planetary Protection assembled an MSR OS Tiger Team (OSTT) to discuss the appropriate cleanliness level options of the interior of the OS. The team's remit was primarily focused on evaluating the trade-offs between Planetary Protection cleanliness levels 4a and 4b. These cleanliness levels are determined by the Committee on Space Research (COSPAR) planetary protection regulations, where 4a requires <300 bacterial spores/m2 and <3 x 105 bacterial spores on the spacecraft (in this case, the interior of the OS) and 4b mandates the more stringent requirement of <30 bacterial spores on the spacecraft. This report documents the consensus opinion submitted by the OSTT that recommended the interior of the OS be cleaned to a 4a requirement with any feasible added effort toward 4b. This report provides, as well, the rationale for that decision.


Assuntos
Marte , Voo Espacial , Meio Ambiente Extraterreno , Planetas , Astronave , Estados Unidos , United States National Aeronautics and Space Administration
4.
Fam Syst Health ; 39(1): 158-162, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-34014737

RESUMO

Why has the health care delivery paradigm and its integral transactions and interactions been left to muddle through, using archaic, 20th century modes and processes of delivery that are overlaid with byz antine medical record databases that pass for "cut ting-edge" technology? What is stalling the digital revolution in the provision of health care services to consumers? Understanding how and why this has happened requires that we briefly explore the evo lution of health care in the United States. Topics discussed include (1): morbidity and mortality: the public health era: (2) Medicare era: the advance of diagnostic and therapeutic technology; (3) the power of the consumer: patient-centered informatics; and (4) planning and execution of strategic transformation of provision of care informatics. Without an informatics focus, our health care system will continue limping along, costing more money and delivering many years of disability. Our most viable solutions revolve around using informatics to measure, guide and become the transformation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Atenção à Saúde/métodos , Invenções/tendências , Informática Médica/tendências , Planejamento Estratégico , Atenção à Saúde/tendências , Humanos , Informática Médica/instrumentação , Estados Unidos
5.
mSystems ; 5(5)2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024053

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019, is a respiratory virus primarily transmitted person to person through inhalation of droplets or aerosols, laden with viral particles. However, as recent studies have shown, virions can remain infectious for up to 72 h on surfaces, which can lead to transmission through contact. Thus, a comprehensive study was conducted to determine the efficiency of protocols to recover SARS-CoV-2 from surfaces in built environments. This end-to-end (E2E) study showed that the effective combination for monitoring SARS-CoV-2 on surfaces includes using an Isohelix swab collection tool, DNA/RNA Shield as a preservative, an automated system for RNA extraction, and reverse transcriptase quantitative PCR (RT-qPCR) as the detection assay. Using this E2E approach, this study showed that, in some cases, noninfectious viral fragments of SARS-CoV-2 persisted on surfaces for as long as 8 days even after bleach treatment. Additionally, debris associated with specific built environment surfaces appeared to inhibit and negatively impact the recovery of RNA; Amerstat demonstrated the highest inhibition (>90%) when challenged with an inactivated viral control. Overall, it was determined that this E2E protocol required a minimum of 1,000 viral particles per 25 cm2 to successfully detect virus from test surfaces. Despite our findings of viral fragment longevity on surfaces, when this method was employed to evaluate 368 samples collected from various built environmental surfaces, all samples tested negative, indicating that the surfaces were either void of virus or below the detection limit of the assay.IMPORTANCE The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (the virus responsible for coronavirus disease 2019 [COVID-19]) pandemic has led to a global slowdown with far-reaching financial and social impacts. The SARS-CoV-2 respiratory virus is primarily transmitted from person to person through inhalation of infected droplets or aerosols. However, some studies have shown that virions can remain infectious on surfaces for days and can lead to human infection from contact with infected surfaces. Thus, a comprehensive study was conducted to determine the efficiency of protocols to recover SARS-CoV-2 from surfaces in built environments. This end-to-end study showed that the effective combination for monitoring SARS-CoV-2 on surfaces required a minimum of 1,000 viral particles per 25 cm2 to successfully detect virus from surfaces. This comprehensive study can provide valuable information regarding surface monitoring of various materials as well as the capacity to retain viral RNA and allow for effective disinfection.

6.
Appl Environ Microbiol ; 74(9): 2646-58, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18344346

RESUMO

Microbial Mn(II) oxidation has important biogeochemical consequences in marine, freshwater, and terrestrial environments, but many aspects of the physiology and biochemistry of this process remain obscure. Here, we report genomic insights into Mn(II) oxidation by the marine alphaproteobacterium Aurantimonas sp. strain SI85-9A1, isolated from the oxic/anoxic interface of a stratified fjord. The SI85-9A1 genome harbors the genetic potential for metabolic versatility, with genes for organoheterotrophy, methylotrophy, oxidation of sulfur and carbon monoxide, the ability to grow over a wide range of O(2) concentrations (including microaerobic conditions), and the complete Calvin cycle for carbon fixation. Although no growth could be detected under autotrophic conditions with Mn(II) as the sole electron donor, cultures of SI85-9A1 grown on glycerol are dramatically stimulated by addition of Mn(II), suggesting an energetic benefit from Mn(II) oxidation. A putative Mn(II) oxidase is encoded by duplicated multicopper oxidase genes that have a complex evolutionary history including multiple gene duplication, loss, and ancient horizontal transfer events. The Mn(II) oxidase was most abundant in the extracellular fraction, where it cooccurs with a putative hemolysin-type Ca(2+)-binding peroxidase. Regulatory elements governing the cellular response to Fe and Mn concentration were identified, and 39 targets of these regulators were detected. The putative Mn(II) oxidase genes were not among the predicted targets, indicating that regulation of Mn(II) oxidation is controlled by other factors yet to be identified. Overall, our results provide novel insights into the physiology and biochemistry of Mn(II) oxidation and reveal a genome specialized for life at the oxic/anoxic interface.


Assuntos
Alphaproteobacteria/enzimologia , Alphaproteobacteria/genética , DNA Bacteriano/genética , Genes Bacterianos , Manganês/metabolismo , Alphaproteobacteria/crescimento & desenvolvimento , Alphaproteobacteria/metabolismo , Proteínas de Bactérias/análise , Biologia Computacional , DNA Bacteriano/química , Eletroforese em Gel de Poliacrilamida , Regulação Bacteriana da Expressão Gênica/genética , Ordem dos Genes , Genômica , Glicerol/metabolismo , Dados de Sequência Molecular , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Filogenia , Homologia de Sequência
7.
Science ; 313(5795): 1955-7, 2006 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-17008530

RESUMO

Soluble manganese(III) [Mn(III)] has been thought to disproportionate to soluble Mn(II) and particulate Mn(IV)O2 in natural waters, although it persists as complexes in laboratory solutions. We report that, in the Black Sea, soluble Mn(III) concentrations were as high as 5 micromolar and constituted up to 100% of the total dissolved Mn pool. Depth profiles indicated that soluble Mn(III) was produced at the top of the suboxic zone by Mn(II) oxidation and at the bottom of the suboxic zone by Mn(IV)O2 reduction, then stabilized in each case by unknown natural ligands. We also found micromolar concentrations of dissolved Mn(III) in the Chesapeake Bay. Dissolved Mn(III) can maintain the existence of suboxic zones because it can act as either an electron acceptor or donor. Our data indicate that Mn(III) should be ubiquitous at all water column and sediment oxic/anoxic interfaces in the environment.

8.
FEMS Microbiol Ecol ; 57(2): 239-50, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16867142

RESUMO

A large number of studies have investigated gastrointestinal microbiota and changes in the gastrointestinal community. However, a concern in these studies is how best to assess changes in gastrointestinal community structure. This paper presents two different human trials where the fecal terminal restriction fragment length polymorphism data sets were analyzed to search for treatment effects. Principle components analysis and cluster analysis based on grouped data are compared with analysis of data by subject using distance coefficients. Comparison with baseline within an individual before grouping by treatment provided a clearer indication of treatment effects than did an evaluation of data grouped before analysis. In addition, a large within-subject sample size and multiple baseline samples are necessary to accurately analyze treatment effects.


Assuntos
Antibacterianos/administração & dosagem , Bactérias/efeitos dos fármacos , Impressões Digitais de DNA , Intestinos/microbiologia , Probióticos/administração & dosagem , Adulto , Bactérias/classificação , Bactérias/genética , Análise por Conglomerados , DNA Bacteriano/genética , Método Duplo-Cego , Fezes/microbiologia , Humanos , Placebos , Polimorfismo de Fragmento de Restrição , Análise de Componente Principal
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