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CURATOR
A pinboard by
Endre Szvetnik

I cover science and tech news for Sparrho and work with Sparrho Heroes to curate, translate and disseminate scientific research to the wider public.

PINBOARD SUMMARY

Stephen Hawking says we might have to leave Earth. But how can we survive in space?

What if what Stephen Hawking says is true and humans need to start looking for a new home beyond Earth? I put together this board to collate papers about the effects of living in space for humans.

12 ITEMS PINNED

MELiSSA the minimal biosphere: Human life, waste and refuge in deep space

Abstract: MELiSSA (Micro-Ecological Life Support System Alternative) is a long-term technology program of the European Space Agency. Its aim is to construct autonomous habitats in deep space, supplying astronauts with fresh air, water and food through continuous microbial recycling of human wastes. This article considers how anticipated futures of space travel and environmental survival are materialized in the project to engineer the minimal biosphere capable of reliably sustaining human life: a human/microbe association with the fewest possible species. We locate MELiSSA within a history of bio-infrastructures associated with colonisation projects: refugia in which organisms dislocated from their originary habitats are preserved. Analysis of MELiSSA’s sewage-composting technology suggests that the disordering complexity of human waste presents a formidable “bottle-neck” for the construction of the minimal biosphere, in turn suggesting our dependence on microbial communities (soil, the human gut) of potentially irreducible biocomplexity. MELiSSA researchers think of themselves as pragmatic enablers of space exploration, yet a wider family of space colonisation projects are now imagined in terms of the prospect that the Earth might cease to function as the minimal biosphere capable of supporting civilisation. MELiSSA’s politics of anticipation are paradoxical, promising technologies with which to escape from the Earth and through which it may be sustained.

Pub.: 06 Jan '17, Pinned: 08 May '17

Cytoskeletal stability and metabolic alterations in primary human macrophages in long-term microgravity.

Abstract: The immune system is one of the most affected systems of the human body during space flight. The cells of the immune system are exceptionally sensitive to microgravity. Thus, serious concerns arise, whether space flight associated weakening of the immune system ultimately precludes the expansion of human presence beyond the Earth's orbit. For human space flight, it is an urgent need to understand the cellular and molecular mechanisms by which altered gravity influences and changes the functions of immune cells. The CELLBOX-PRIME (= CellBox-Primary Human Macrophages in Microgravity Environment) experiment investigated for the first time microgravity-associated long-term alterations in primary human macrophages, one of the most important effector cells of the immune system. The experiment was conducted in the U.S. National Laboratory on board of the International Space Station ISS using the NanoRacks laboratory and Biorack type I standard CELLBOX EUE type IV containers. Upload and download were performed with the SpaceX CRS-3 and the Dragon spaceship on April 18th, 2014 / May 18th, 2014. Surprisingly, primary human macrophages exhibited neither quantitative nor structural changes of the actin and vimentin cytoskeleton after 11 days in microgravity when compared to 1g controls. Neither CD18 or CD14 surface expression were altered in microgravity, however ICAM-1 expression was reduced. The analysis of 74 metabolites in the cell culture supernatant by GC-TOF-MS, revealed eight metabolites with significantly different quantities when compared to 1g controls. In particular, the significant increase of free fucose in the cell culture supernatant was associated with a significant decrease of cell surface-bound fucose. The reduced ICAM-1 expression and the loss of cell surface-bound fucose may contribute to functional impairments, e.g. the activation of T cells, migration and activation of the innate immune response. We assume that the surprisingly small and non-significant cytoskeletal alterations represent a stable "steady state" after adaptive processes are initiated in the new microgravity environment. Due to the utmost importance of the human macrophage system for the elimination of pathogens and the clearance of apoptotic cells, its apparent robustness to a low gravity environment is crucial for human health and performance during long-term space missions.

Pub.: 19 Apr '17, Pinned: 08 May '17

Exercise in space: the European Space Agency approach to in-flight exercise countermeasures for long-duration missions on ISS.

Abstract: To counteract microgravity (µG)-induced adaptation, European Space Agency (ESA) astronauts on long-duration missions (LDMs) to the International Space Station (ISS) perform a daily physical exercise countermeasure program. Since the first ESA crewmember completed an LDM in 2006, the ESA countermeasure program has strived to provide efficient protection against decreases in body mass, muscle strength, bone mass, and aerobic capacity within the operational constraints of the ISS environment and the changing availability of on-board exercise devices. The purpose of this paper is to provide a description of ESA's individualised approach to in-flight exercise countermeasures and an up-to-date picture of how exercise is used to counteract physiological changes resulting from µG-induced adaptation. Changes in the absolute workload for resistive exercise, treadmill running and cycle ergometry throughout ESA's eight LDMs are also presented, and aspects of pre-flight physical preparation and post-flight reconditioning outlined.With the introduction of the advanced resistive exercise device (ARED) in 2009, the relative contribution of resistance exercise to total in-flight exercise increased (33-46 %), whilst treadmill running (42-33 %) and cycle ergometry (26-20 %) decreased. All eight ESA crewmembers increased their in-flight absolute workload during their LDMs for resistance exercise and treadmill running (running speed and vertical loading through the harness), while cycle ergometer workload was unchanged across missions.Increased or unchanged absolute exercise workloads in-flight would appear contradictory to typical post-flight reductions in muscle mass and strength, and cardiovascular capacity following LDMs. However, increased absolute in-flight workloads are not directly linked to changes in exercise capacity as they likely also reflect the planned, conservative loading early in the mission to allow adaption to µG exercise, including personal comfort issues with novel exercise hardware (e.g. the treadmill harness). Inconsistency in hardware and individualised support concepts across time limit the comparability of results from different crewmembers, and questions regarding the difference between cycling and running in µG versus identical exercise here on Earth, and other factors that might influence in-flight exercise performance, still require further investigation.

Pub.: 05 Aug '16, Pinned: 08 May '17

What happens to your brain on the way to Mars.

Abstract: As NASA prepares for the first manned spaceflight to Mars, questions have surfaced concerning the potential for increased risks associated with exposure to the spectrum of highly energetic nuclei that comprise galactic cosmic rays. Animal models have revealed an unexpected sensitivity of mature neurons in the brain to charged particles found in space. Astronaut autonomy during long-term space travel is particularly critical as is the need to properly manage planned and unanticipated events, activities that could be compromised by accumulating particle traversals through the brain. Using mice subjected to space-relevant fluences of charged particles, we show significant cortical- and hippocampal-based performance decrements 6 weeks after acute exposure. Animals manifesting cognitive decrements exhibited marked and persistent radiation-induced reductions in dendritic complexity and spine density along medial prefrontal cortical neurons known to mediate neurotransmission specifically interrogated by our behavioral tasks. Significant increases in postsynaptic density protein 95 (PSD-95) revealed major radiation-induced alterations in synaptic integrity. Impaired behavioral performance of individual animals correlated significantly with reduced spine density and trended with increased synaptic puncta, thereby providing quantitative measures of risk for developing cognitive decrements. Our data indicate an unexpected and unique susceptibility of the central nervous system to space radiation exposure, and argue that the underlying radiation sensitivity of delicate neuronal structure may well predispose astronauts to unintended mission-critical performance decrements and/or longer-term neurocognitive sequelae.

Pub.: 17 Jul '15, Pinned: 08 May '17

A voyage to Mars: Space radiation, aging, and nutrition

Abstract: On exploratory class missions, such as a voyage to Mars, astronauts will be exposed to doses and types of radiation that are not experienced in low earth orbit where the space shuttle and International Space Station operate. Astronauts who participate in exploratory class missions outside the magnetic field of the earth will be exposed to galactic cosmic rays which are composed of alpha particles, protons and particles of high energy and charge. Exposure to cosmic rays produces changes in neuronal and behavioral functioning which are characteristic of aged organisms. As has been observed with aging, maintaining rats on antioxidant berry diets can prevent/ameliorate the radiation-induced changes in neural and behavioral function. As such, these diets have the potential to provide protection to astronauts from the deleterious effects of exposure to space radiation. Content Type Journal ArticlePages 233-241DOI 10.3233/NUA-140045Authors Bernard M. Rabin, Department of Psychology, University of Maryland Baltimore County, Baltimore, MD, USABarbara Shukitt-Hale, Human Nutrition Research Center on Aging, USDA-ARS, Tufts University, Boston, MA, USA Journal Nutrition and AgingOnline ISSN 1879-7725Print ISSN 1879-7717 Journal Volume Volume 2 Journal Issue Volume 2, Number 4 / 2014 On exploratory class missions, such as a voyage to Mars, astronauts will be exposed to doses and types of radiation that are not experienced in low earth orbit where the space shuttle and International Space Station operate. Astronauts who participate in exploratory class missions outside the magnetic field of the earth will be exposed to galactic cosmic rays which are composed of alpha particles, protons and particles of high energy and charge. Exposure to cosmic rays produces changes in neuronal and behavioral functioning which are characteristic of aged organisms. As has been observed with aging, maintaining rats on antioxidant berry diets can prevent/ameliorate the radiation-induced changes in neural and behavioral function. As such, these diets have the potential to provide protection to astronauts from the deleterious effects of exposure to space radiation. Content Type Journal ArticlePages 233-241DOI 10.3233/NUA-140045Authors Bernard M. Rabin, Department of Psychology, University of Maryland Baltimore County, Baltimore, MD, USABarbara Shukitt-Hale, Human Nutrition Research Center on Aging, USDA-ARS, Tufts University, Boston, MA, USA Content Type Journal ArticleContent Type Journal ArticlePages 233-241DOI 10.3233/NUA-140045Authors Bernard M. Rabin, Department of Psychology, University of Maryland Baltimore County, Baltimore, MD, USABarbara Shukitt-Hale, Human Nutrition Research Center on Aging, USDA-ARS, Tufts University, Boston, MA, USA Authors Bernard M. Rabin, Department of Psychology, University of Maryland Baltimore County, Baltimore, MD, USABarbara Shukitt-Hale, Human Nutrition Research Center on Aging, USDA-ARS, Tufts University, Boston, MA, USA Bernard M. Rabin, Department of Psychology, University of Maryland Baltimore County, Baltimore, MD, USABarbara Shukitt-Hale, Human Nutrition Research Center on Aging, USDA-ARS, Tufts University, Boston, MA, USA Journal Nutrition and AgingOnline ISSN 1879-7725Print ISSN 1879-7717 Journal Volume Volume 2 Journal Issue Volume 2, Number 4 / 2014 Journal Nutrition and AgingOnline ISSN 1879-7725Print ISSN 1879-7717 Journal Nutrition and AgingJournal Nutrition and AgingNutrition and AgingOnline ISSN 1879-7725Online ISSN 1879-7725Print ISSN 1879-7717Print ISSN 1879-7717 Journal Volume Volume 2 Journal Volume Volume 2Journal Volume Volume 2 Journal Issue Volume 2, Number 4 / 2014 Journal Issue Volume 2, Number 4 / 2014Journal Issue Volume 2, Number 4 / 2014Volume 2, Number 4 / 2014

Pub.: 19 Jun '14, Pinned: 08 May '17

Charged iron particles, components of space radiation, destroy ovarian follicles.

Abstract: Do charged iron particles, components of space radiation, cause premature ovarian failure?Exposure to charged iron particles causes ovarian DNA damage, oxidative damage and apoptosis, resulting in premature ovarian failure.The ovary is very sensitive to follicle destruction by low linear energy transfer (LET) radiation, such as X-rays and γ-rays. However, it is completely unknown whether high-LET radiation, such as charged iron particles, also destroys ovarian follicles.Twelve week old C57BL/6J female mice were exposed to single doses of 0, 5, 30 or 50 cGy (n = 8/group) charged iron particles (LET = 179 keV/µm) at energy of 600 MeV/u. Two groups were irradiated at the highest dose, one fed AIN-93M chow and the other fed AIN-93M chow supplemented with 150 mg/kg diet alpha lipoic acid (ALA).We quantified the numbers of ovarian follicles, measured serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) concentrations, and analyzed histone H2AX phosphorylation, oxidative damage and apoptosis markers in the ovarian follicles.H2AX phosphorylation, lipid peroxidation, protein nitration and apoptosis were highly induced in ovarian follicles at 6 h and remained increased 1 week after irradiation. As a result, numbers of healthy ovarian follicles were significantly and dose-dependently depleted at 1 and 8 weeks post-irradiation, with 57, 84 and 99% decreases in primordial follicles at 8 weeks at the 5, 30 and 50 cGy doses, respectively (P < 0.05 versus 0 cGy). Consistent with near-total depletion of ovarian follicles in the 50 cGy group, serum concentrations of FSH and LH were significantly elevated at 8 weeks. Dietary supplementation with ALA partially prevented the adverse ovarian effects of 50 cGy iron particles.About 21% of the estimated radiation dose from exposure to galactic cosmic rays during a multi-year Mars mission will be due to high-LET particles, of which iron is only one. The effects of galactic cosmic rays, which contain a mixture of multiple charged particles, as well as protons, neutrons, and helium ions, may differ from the effects of iron alone.We show for the first time that charged high-LET ions are highly damaging to the ovary even at low doses, causing premature ovarian failure. In addition to raising concerns for female astronauts, these findings raise concerns for ovarian damage due to clinical uses of high-LET particles for cancer treatment. In addition to causing infertility, premature ovarian failure has adverse implications for the functions of heart, brain, bone and muscle later in life.This work was supported by a National Aeronautics and Space Administration grant NNX14AC50G to U.L. B.M. was partially supported by a National Space Biomedical Research Institute First Award, PF04302. Additional support was received from the University of California Irvine Center for Occupational and Environmental Health. The authors have no conflicts of interests.

Pub.: 03 Jun '16, Pinned: 08 May '17