Microscopic Superheroes to Help Protect Astronaut Health in Space (Astronomy)

It’s a classic superhero tale: Inconspicuous, underestimated, our hero is revealed to have powers beyond imagination! The hottest and coldest environments on Earth, decades without water, the powerful radiation of space – none of it is any match for…the tardigrade!

This chubby, microscopic, eight-legged animal may be an unlikely hero, but tardigrades, also known as water bears due to their shape under a microscope, possess superpowers when it comes to surviving really harsh conditions. Understanding how they tolerate extreme environments – including the one astronauts experience in space, with microgravity and elevated radiation levels – can better guide research into protecting humans from the stresses of long-duration space travel. An experiment starting aboard the International Space Station, called Cell Science-04, will help reveal how tardigrades do it.

“We want to see what ‘tricks’ they use to survive when they arrive in space, and, over time, what tricks their offspring are using,” said Thomas Boothby, assistant professor at the University of Wyoming in Laramie and principal investigator of the experiment. “Are they the same or do they change across generations? We just don’t know what to expect.”

Credits: NASA/Ames Research Center

One option in the tardigrade bag of tricks could be producing tons more antioxidants to combat harmful changes in the body caused by increased radiation exposure in space.

“We have seen them do this in response to radiation on Earth,” said Boothby, “and we think the ways tardigrades have evolved to withstand extreme environments on this planet may also be what protects them against the stresses of spaceflight.”

The research team will look at what happens with tardigrade genes in space. Knowing which ones are turned on or off in response to short-term and long-term spaceflight will help researchers identify specific ways tardigrades use to survive in this stressful environment. If one solution they have is to turn up the dial on antioxidant production, for example, genes involved in that process should be affected.

Checking which genes are also activated or deactivated by other stresses will help pinpoint the genes that respond exclusively to spaceflight. Cell Science-04 will then test which are truly required for tardigrade adaptation and survival in this high-stress environment.

Data from the space station experiment will also offer a comparison for Earth-based research. The latter is more common and less costly, and uses simulated spaceflight conditions to study tardigrade responses. The current experiment will tell researchers how similar those conditions are to actual spaceflight.

The tiny heroes of Cell Science-04 won’t be the first spacefaring tardigrades to join an astronaut crew. They have already been shown to survive even the vacuum of space when exposed outside the space station for an experiment. This time, they’ll be on board living and reproducing inside special science hardware developed for the station by NASA’s Ames Research Center in California’s Silicon Valley, which also manages the mission. Called the Bioculture System, the hardware lets scientists carry out long-term studies of cultures of cells, tissues, and microscopic animals in space by allowing real-time, remote monitoring, and finer control over the conditions in which they grow.

In the long run, revealing what makes tardigrades so tolerant could lead to ways of protecting biological material, such as food and medicine from extreme temperatures, drying out, and radiation exposure, which will be invaluable for long-duration, deep-space exploration missions. That’s superhero-size potential for the teeny tardigrade.

Dr. Boothby’s research is supported by NASA’s Biological and Physical Sciences Division.


Provided by NASA

Giant Low Surface Brightness Galaxies (Cosmology)

Forty years ago astronomers using sensitive new imaging techniques discovered a class of large, faint galaxies they named low surface brightness galaxies. Giant low surface brightness galaxies (gLSBGs) are a subset whose masses are comparable to the Milky Way’s but whose radii are ten times bigger, as much as four hundred thousand light-years. These gLSBGs raise a problem for astronomers: despite being massive, the galaxy disks are (kinematically speaking) relatively inactive. The usual formation paradigm for high mass galaxies imagines them evolving out of galaxy mergers, a process that stirs up the disk and should make it kinematically active. Moreover, most gLSBGs are found with no other galaxies in their vicinities suggesting that collisions were probably not important in their formation.

The question of how gLSBGs form is a matter of active debate. Two popular models have been proposed. In the first, the non-catastrophic scenario, slow gas accretion onto the galaxy leads to its growth. In the alternative, the catastrophic scenario, a merger event did occur in the past; the major advantage of this model is that it fits within the current galaxy formation framework. CfA astronomer Igor Chilingarian and his colleagues have completed sensitive optical observations of seven gLSBGs, taking spectra across the full diameters of these faint, giant systems, and combining their results with archival optical and radio measurement of atomic hydrogen emission. Their new paper is the latest in a series of results on gLSBGs.

The astronomers used the large dataset to test these two scenarios; they also considered a third option in which the galaxies form within an unusually shallow dark matter halo and its gravitational influence. (All galaxies are thought to have dark matter haloes; the Milky Way’s halo contains ten times more mass than is present in stars.) They conclude that all three scenarios appear to be operating but in different situations. For most of their sample, the most likely process was formation by growth through gradual accretion after initial galaxy formation. For remaining gLSBGs, the major merger scenario explained the observations better, although in a few cases they found that a sparse dark matter halo could also play a role. The scientists also discovered that at least six of their seven gLSBGs host active galactic nuclei (AGN), however their supermassive black hole nuclei are much less massive than those in normal galaxies of similar mass, implying that mergers, even if they were involved in forming gLSBGs, must have been comparatively modest.

Featured image: The giant, low surface brightness galaxy Malin 1 as imaged by the Megacam instrument on the 6.5m Magellan/Clay telescope. Astronomers puzzled by how these giant systems form have completed a new study that confirms several proposed avenues are likely. © Gaspar Galaz et al 2015 ApJ 815 L29


Reference: “Observational Insights on the Origin of Giant Low Surface Brightness Galaxies,” Anna S. Saburova, Igor V. Chilingarian, Anastasia V. Kasparova, Olga K. Sil’chenko, Kirill A. Grishin, Ivan Yu. Katkov, and Roman I. Uklein, Monthly Notices of the Royal Astronomical Society 503, 830, 2021.


Provided by CFA Harvard

New Species of Milk Weed Family Found in Mount Emei (Botany)

Vincetoxicum is a genus of the milk weed family (Apocynaceae) which comprises 378 genera and about 5,350 speciesSpecies of Vincetoxicum are shrubs, erect perennial herbs or herbaceous twiners. There are approximately 70 species of Vincetoxicum occurring in China, most of them are distributed in tropical or subtropical regions. 

During an expedition to Mount Emei, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) and their collaborators collected an unknown species of Vincetoxicum in May 2020 from the evergreen broad–leaved forest in Emeishan City. After literature review as well as morphological examination, they found it different from any other species of Vincetoxicum in morphological characters and confirmed it as new to science.  

The researchers named the new species as Vincetoxicum emeiense and got it published in Phytotaxa.

Corolla lobes of Vincetoxicum emeiense. (Image by SHEN Jianyong)

Vincetoxicum emeiense is a twining plant. It is similar to V. hui and V. koi. in twining herbaceous life form, leaf, pleiochasium and corolla shape, but there are numerous features that can be used to distinguish them. 

Vincetoxicum emeiense has glabrous stem and adaxially puberulent leaf shape, and with adaxially puberulent and orange to purple corolla.

Flowering branch of Vincetoxicum emeiense. (Image by SHEN Jianyong)

The new species is so far only recorded from the type locality, Mount Emei, Sichuan Province at an elevation of about 757 meters, where it grows in evergreen broad–leaved forest. 

Since the investigation has not been thorough enough to fully understand the species natural distribution, the researchers regarded the conservation status of the new species as Data Dedicient according to the International Union for Conservation of Nature Red List categories and criteria. 

Inflorescence of Vincetoxicum emeiense. (Image by SHEN Jianyong)

Featured image: Flowering branch of Vincetoxicum emeiense. (Image by SHEN Jianyong)


Reference

Vincetoxicum emeiense (Asclepiadeae, Asclepiadoideae, Apocynaceae), a new species from Sichuan, China


Provided by Chinese Academy of Sciences

Covering Soil Substrate on Sand Surface Helps Colonization and Development of Artificial Biological Soil Crusts

Biological soil crusts (BSCs), also called “living skin” on the soil surface, are a community of interacting autotrophic and heterotrophic organisms, which are found in many low-productivity ecosystems around the world. 

In recent years, artificial BSCs have become one of the most promising biotechnological strategies for preventing soil erosion and restoring soil functionality in degraded drylands. However, how to quickly and massively cultivate BSCs and its field colonization method is the technical bottleneck of large-scale use of this achievement. 

In a study published in Soil & Tillage Research, researchers from the Northwest Institute of Eco-Environment and Resources (NIEER) of the Chinese Academy of Sciences (CAS) investigated the effects of four soil substrates collected from the southeast edge of the temperate Tengger Desert in northern China on the colonization and development of artificial BSCs. 

They tested how clay barrier methods influenced the establishment of artificial BSCs in a natural desert environment, evaluated the effects of different soil substrate fine material and nutrient contents on the colonization and development of artificial BSCs and selected the ideal soil substrate used to cultivate artificial BSC organisms in temperate desert ecosystems. 

Results indicated that covering sand with soil substrates improved BSC recovery rates in the field conditions. Covering sand with soil substrates created more ideal soil habitats because soil substrates have higher sand surface stability, greater initial finer material content and greater nutrient content, and delayed soil surface wetness duration than sandy substrates. 

Besides, considering the scarcity of soil resources and the value of reusing soil resources, the researchers suggested that left-over soils from dredged irrigation channels and abandoned farmlands could provide a good substrate to culture BSC inoculum material. 

This study provides potential materials for large-scale ecological restoration projects in temperate dryland regions in the future.

Featured image: Map of soil Substrate © Yang Zhao et al.


Reference: Yang Zhao, Wenwen Xu, Nan Wang, Effects of covering sand with different soil substrates on the formation and development of artificial biocrusts in a natural desert environment, Soil and Tillage Research, Volume 213, 2021, 105081, ISSN 0167-1987, https://doi.org/10.1016/j.still.2021.105081. (https://www.sciencedirect.com/science/article/pii/S0167198721001513)


Provided by Chinese Academy of Sciences

How Does Aerosol Water Content Affect Formation of Secondary Inorganic Aerosol? (Earth Science)

Sulfate, nitrate and ammonium are the most abundant secondary inorganic aerosols (SIA) in atmospheric fine particle matter (PM2.5). Meteorological conditions, gas-particle transportation process, and aerosol acidity (pH) can influence SIA formation.

Recently, a research group from the Institute of Earth Environment of the Chinese Academy of Sciences and their collaborators have jointly investigated how aerosol water content affect the formation of secondary inorganic aerosol.

The researchers conducted semi-continuous measurements of water-soluble inorganic ions during a winter extreme pollution event in Xi’an, northwest China. The ISORROPIA-II thermodynamic model was used to calculate aerosol acidity and water content.

They found that the increase in nitrogen oxidation ratios (NOR) and ammonia conversion ratio (NHR, the gas-particle partitioning of ammonium) from normal days to haze days were greater when compared to sulfur oxidation ratios (SOR).

In the polluted periods, sulfate and nitrate formations were facilitated by water content increase. Strong linear correlation coefficients between SOR and NOR with aerosol water content indicated that the gas-liquid reaction of SO2 and NO2 is the major pathway of sulfate and nitrate formation during severe haze episodes.

In contrast, the NHR and aerosol water content exhibited a logarithmic relationship, which revealsed that when water content was greater than 100μg·m-3, the gas-particle partitioning ratio of ammonium was basically unchanged following an increase in water content.

The study was published in Atmospheric Environment on March 2.


Reference: T. Zhang, Z.X. Shen, H. Su, S.X. Liu, J.M. Zhou, Z.Z. Zhao, Q.Y. Wang, A.S.H. Prévôt, J.J. Cao, Effects of Aerosol Water Content on the formation of secondary inorganic aerosol during a Winter Heavy PM2.5 Pollution Episode in Xi’an, China, Atmospheric Environment, Volume 252, 2021, 118304, ISSN 1352-2310, https://doi.org/10.1016/j.atmosenv.2021.118304. (https://www.sciencedirect.com/science/article/pii/S1352231021001229)


Provided by Chinese Academy of Sciences

Scientists Reveal Effects of Water on 660 km Discontinuity in the Deep Earth (Earth Science)

The seismic discontinuity that occurs at an average depth of 647-654 km, usually called the 660 km seismic discontinuity, is the boundary between the transition zone and the lower mantle. It is considered to be caused by the transformation of ringwoodite to bridgmanite and MgO (post-spinel transition).

One important parameter that can potentially affect the post-spinel transition is hydration. According to recent studies, the transition zone may contain significant amounts of water, and thus understanding the effect of water on the post-spinel transition is important to determine its properties.

Dr. Joshua Muir, the postdoctoral researcher, and the team leader Prof. ZHANG Feiwu from the Institute of Geochemistry of the Chinese Academy of Sciences (IGCAS), in collaboration with Prof. John Brodholt from University College London (UCL), investigated the effect of water on the post-spinel transition at high temperatures and pressures.

The results indicated that the water only had a very small effect on the Clapeyron slope of the post-spinel transition. On the other hand, water had a moderate effect on its depth. 1 wt.% water increased the depth of phase transition onset by about 8 km. This variation on depth was relatively small compared to seismically observed variations in the 660 km discontinuity of around 35 km and so water alone could not account for the observed 660 km discontinuity topography.

Furthermore, this study demonstrated that the addition of water caused a large broadening of the three-phase loop (ringwoodite + bridgmanite + MgO) through the development of post-spinel transition. The width of the phase loop was negligible for water contents less than about 1000 ppm, but then grew rapidly to become about 10 km wide, before shrinking again as the water content approaches ringwoodite saturation.

The study, published in Earth and Planetary Science Letters on April 14, was supported by the National Natural Science Foundation of China, PIFI from Chinese Academy of Sciences (CAS) and NERC Grants.

Phase boundary for post-spinel transition (top), and the width of the three-phase loop as a function of water content at 1873 K (bottom) (Image by IGCAS)

Reference: Joshua M.R. Muir, Feiwu Zhang, John P. Brodholt, The effect of water on the post-spinel transition and evidence for extreme water contents at the bottom of the transition zone, Earth and Planetary Science Letters, Volume 565, 2021, 116909, ISSN 0012-821X, https://doi.org/10.1016/j.epsl.2021.116909. (https://www.sciencedirect.com/science/article/pii/S0012821X21001680)


Provided by Chinese Academy of Sciences

Modeling Reveals What Drives Snow Mass Variation in Tianshan Mountains (Earth Science)

Seasonal snow mass is an essential natural resource in the Tianshan Mountains. Climate warming alters the snowmelt timing and shortens the snow cover duration. 

However, a reliable estimation of snow mass in the Tianshan Mountains is still unclear due to the scarcity of extensive continuous surface observations and a complex spatial heterogeneity. 

A research group of Xinjiang Institute of Ecology and Geography (XIEG) of Chinese Academy of Sciences, in cooperation with scientists from Ghent University and Royal Meteorological Institute in Belgium, revealed the variations of snow mass and its forcing drivers in the Tianshan Mountains by means of the WRF/Noah-MP model and remote sensing vegetation products. 

A long-time snow simulation from 1982 to 2018 indicated that the March snow mass represented the annual maximum snow storage in the entire Tianshan Mountains and exhibited a negligible trend.  

The total precipitation amount during the cold season (November-March) controlled the variations of the March snow mass. The increased precipitation in the high-altitude regions contributed to the extensive snow mass, which could offset snow mass loss in the low-altitude regions of the Tianshan Mountains.  

Additionally, the March snow cover fraction declined significantly, which was mainly attributed to a rapid increase of air temperature in March, particularly in the Southern Tianshan Mountains. 

In their previous study, the researchers also revealed the influences of key vegetation parameters on snow simulation. Compared with default vegetation parameters, more realistic remote sensing vegetation parameters could improve the performance of snow simulation in the WRF/Noah-MP through reducing the loss of intercepted snow and melted snow, especially in the forest regions. 

Related studies were published in Journal of Geophysical Research: Atmospheres and Journal of Hydrology.


References: (1) Yang, T., Li, Q., Chen, X., Hamdi, R., De Maeyer, P., & Li, L. (2021). Variation of snow mass in a regional climate model downscaling simulation covering the Tianshan Mountains, Central Asia. Journal of Geophysical Research: Atmospheres, 126, e2020JD034183. https://doi.org/10.1029/2020JD034183 (2) Tao Yang, Qian Li, Xi Chen, Rafiq Hamdi, Philippe De Maeyer, Alishir Kurban, Lanhai Li, Improving snow simulation with more realistic vegetation parameters in a regional climate model in the Tianshan Mountains, Central Asia, Journal of Hydrology, Volume 590, 2020, 125525, ISSN 0022-1694, https://doi.org/10.1016/j.jhydrol.2020.125525. (https://www.sciencedirect.com/science/article/pii/S0022169420309859)


Provided by Chinese Academy of Sciences

Quantum Holds The Key To Secure Conference Calls (Quantum)

The world is one step closer to ultimately secure conference calls, thanks to a collaboration between Quantum Communications Hub researchers and their German colleagues, enabling a quantum-secure conversation to take place between four parties simultaneously.

The demonstration, led by Hub researchers based at Heriot-Watt University and published in Science Advances, is a timely advance, given the global reliance on remote collaborative working, including conference calls, since the start of the C19 pandemic.

There have been reports of significant escalation of cyber-attacks on popular teleconferencing platforms in the last year. This advance in quantum secured communications could lead to conference calls with inherent unhackable security measures, underpinned by the principles of quantum physics.

Senior author, Professor Alessandro Fedrizzi, who led the team at Heriot-Watt, said: “We’ve long known that quantum entanglement, which Albert Einstein called ‘spooky action at a distance’ can be used for distributing secure keys. Our work is the first example where this was achieved via ‘spooky action’ between multiple users at the same time — something that a future quantum internet will be able to exploit.”

Secure communications rely upon the sharing of cryptographic keys. The keys used in most systems are relatively short and can therefore be compromised by hackers, and the key distribution procedure is under increasing threat from quickly advancing quantum computers. These growing threats to data security require new, secure methods of key distribution.

A mature quantum technology called Quantum Key Distribution (QKD), deployed in this demonstration in a network scenario for the first time, harnesses the properties of quantum physics to facilitate guaranteed secure distribution of cryptographic keys.

QKD has been used to secure communications for over three decades, facilitating communications of over 400km over terrestrial optical fibre and recently even through space, however, crucially, these communications have only ever occurred exclusively between two parties, limiting the practicality of the technology used to facilitate secure conversations between multiple users.

The system demonstrated by the team here utilises a key property of quantum physics, entanglement, which is the property of quantum physics that gives correlations – stronger than any with which we are familiar in everyday life – between two or more quantum systems, even when these are separated by large distances.

By harnessing multi-party entanglement, the team were able to share keys simultaneously between the four parties, through a process known as ‘Quantum Conference Key Agreement’, overcoming the limitations of traditional QKD systems to share keys between just two users, and enabling the first quantum conference call to occur with an image of a Cheshire cat shared between the four parties, separated by up to 50 km of optical fibre.

Entanglement-based quantum networks are just one part of a large programme of work that the Quantum Communications Hub is undertaking to deliver future quantum secured networks.

The technology demonstrated here has potential to drastically reduce the resource costs for conference calls in quantum networks when compared to standard two-party QKD methods. It is one of the first examples of the expected benefits of a future quantum internet, which is expected to supply entanglement to a system of globally distributed nodes.


Reference: Massimiliano Proietti, Joseph Ho, Federico Grasselli, Peter Barrow, Mehul Malik, Alessandro Fedrizzi, “Experimental quantum conference key agreement”, Science Advances  04 Jun 2021: Vol. 7, no. 23, eabe0395 DOI: https://doi.org/10.1126/sciadv.abe0395


Provided by Heriot-Watt University