воскресенье, 16 июня 2019 г.

Seeing Candida Differently We’re all fundamentally the same…

Seeing Candida Differently

We’re all fundamentally the same yet can look vastly different from each other. Turn to the microbe Candida albicans and it too shows considerable differences within its species. This pathogenic yeast forms almost impenetrable sheets called biofilms when infecting humans, making treatment difficult. Research however often focuses on just one strain of C. albicans. Now researchers look at the effects of mutating four key genes needed for biofilm production in the strain most commonly studied in the lab as well as several others isolated from patients. Using confocal microscopy, they visualised the production of projections called hyphae (pictured), a key feature of C. albicans biofilms. They found the effects of each mutation (second to fourth columns) relative to the normal state (far left column) varied significantly across strains (rows, top to bottom). To get a more complete picture of how C. albicans functions, research into multiple strains is therefore needed.

Written by Lux Fatimathas

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Rare ‘superflares’ could one day threaten Earth

Astronomers probing the edges of the Milky Way have in recent years observed some of the most brilliant pyrotechnic displays in the galaxy: superflares.

Rare 'superflares' could one day threaten Earth
Artist’s depiction of a superflare on an alien star 
[Credit: NASA, ESA & D. Player]

These events occur when stars, for reasons that scientists still don’t understand, eject huge bursts of energy that can be seen from hundreds of light years away. Until recently, researchers assumed that such explosions occurred mostly on stars that, unlike Earth’s, were young and active.

Now, new research shows with more confidence than ever before that superflares can occur on older, quieter stars like our own—albeit more rarely, or about once every few thousand years.

The results should be a wake-up call for life on our planet, said Yuta Notsu, the lead author of the study and a visiting researcher at CU Boulder.

If a superflare erupted from the sun, he said, Earth would likely sit in the path of a wave of high-energy radiation. Such a blast could disrupt electronics across the globe, causing widespread black outs and shorting out communication satellites in orbit.

Notsu presented his research at a press briefing at the 234th meeting of the American Astronomical Society in St. Louis.

«Our study shows that superflares are rare events,» said Notsu, a researcher in CU Boulder’s Laboratory for Atmospheric and Space Physics. «But there is some possibility that we could experience such an event in the next 100 years or so.»

Scientists first discovered this phenomenon from an unlikely source: the Kepler Space Telescope. The NASA spacecraft, launched in 2009, seeks out planets circling stars far from Earth. But it also found something odd about those stars themselves. In rare events, the light from distant stars seemed to get suddenly, and momentarily, brighter.

Researchers dubbed those humungous bursts of energy «superflares.»

Notsu explained that normal-sized flares are common on the sun. But what the Kepler data was showing seemed to be much bigger, on the order of hundreds to thousands of times more powerful than the largest flare ever recorded with modern instruments on Earth.

And that raised an obvious question: Could a superflare also occur on our own sun?

«When our sun was young, it was very active because it rotated very fast and probably generated more powerful flares,» said Notsu, also of the National Solar Observatory in Boulder. «But we didn’t know if such large flares occur on the modern sun with very low frequency.»

To find out, Notsu and an international team of researchers turned to data from the European Space Agency’s Gaia spacecraft and from the Apache Point Observatory in New Mexico. Over a series of studies, the group used those instruments to narrow down a list of superflares that had come from 43 stars that resembled our sun. The researchers then subjected those rare events to a rigorous statistical analysis.

The bottom line: age matters. Based on the team’s calculations, younger stars tend to produce the most superflares. But older stars like our sun, now a respectable 4.6 billion years old, aren’t off the hook.

«Young stars have superflares once every week or so,» Notsu said. «For the sun, it’s once every few thousand years on average.»

The group published its latest results in May in The Astrophysical Journal.

Notsu can’t be sure when the next big solar light show is due to hit Earth. But he said that it’s a matter of when, not if. Still, that could give humans time to prepare, protecting electronics on the ground and in orbit from radiation in space.

«If a superflare occurred 1,000 years ago, it was probably no big problem. People may have seen a large aurora,» Notsu said. «Now, it’s a much bigger problem because of our electronics.»

Author: Daniel Strain | Source: University of Colorado at Boulder [June 11, 2019]



The atmosphere of a new ultra hot Jupiter is analyzed

The combination of observations made with the CARMENES spectrograph on the 3.5m telescope at Calar Alto Observatory (Almería), and the HARPS-N spectrograph on the National Galileo Telescope (TNG) at the Roque de los Muchachos Observatory (Garafía, La Palma) has enabled a team from the Instituto de Astrofísica de Canarias (IAC) to reveal new details about this extrasolar planet, which has a surface temperature of around 2000 K.

The atmosphere of a new ultra hot Jupiter is analyzed
Artist’s impression of ultra hot Jupiter MASCARA-2B/KELT-20b
[Credit: Gabriel Pérez Díaz, SMM (IAC)]

MASCARA-2B/KELT-20b is an ultra hot Jupiter. It belongs to a new group of exoplanets, the hottest known until now, which can reach temperatures at the surface of over 2,000 K. The reason for its high temperature is the proximity of its orbit around its host star, causing it to receive a large flux of radiation in the upper layers of its atmosphere.
The team, led by IAC researcher Núria Casasayas, which had already made initial measurements of the atmosphere during 2018, observed the planet during four transits. They used the HARP-N spectrograph on the National Galileo Telescope (TNG) at the Roque de los Muchachos Observatory (Garafía, La Palma) and the CARMENES spectrograph on the 3.5 m telescope of the Calar Alto Observatory (Almería).

Artistic simulation of ultra hot Jupiter MASCARA-2B/KELT-20b
[Credit: Gabriel Pérez Díaz, SMM (IAC)]

«The two instruments sample slightly different wavelength regions, which allows us to sample a wider spectral range,» explains Casasayas. She adds: «We have been able to detect hydrogen beta, singly ionized iron and magnesium with data from HARPS-N, while the presence of ionized calcium was detected only by using CARMENES. Neutral sodium and hydrogen alpha are detected with both instruments.»
The study of exoplanetary atmospheres has become front line research in recent years. Instruments that perform high-resolution spectroscopy allow us not only to discover the atmospheric composition of planets outside the Solar System, but also to measure other important parameters such as the temperatures of the layers where their constituents are found, and other parameters of the dynamics of the atmosphere.

Source: Instituto de Astrofísica de Canarias [June 11, 2019]



Almost 600 plants have already gone extinct

For the first time ever, scientists at the Royal Botanic Gardens, Kew and Stockholm University, have compiled a global analysis of all plant extinction records documented from across the world. This unique dataset published in leading journal, Nature Ecology & Evolution, brings together data from fieldwork, literature and herbarium specimens, to show how many plant species have gone extinct in the last 250 years, what they are, where they have disappeared from, and what lessons we can learn to stop future extinction.

Almost 600 plants have already gone extinct
Many attempts were made to propagate the The St Helena olive, Nesiota elliptica, and two trees propagated from this
original tree survived on the island until they succumbed to a devastating termite attack and fungal infections in 2003.
No living material could be salvaged, but a sample of its genetic material (DNA) was collected for storage
in Kew’s DNA bank. Fortunately, this precious resource is still available for research
[Credit: Rebecca Cairns-Wicks]

The study found that 571 plant species have disappeared in the last two and a half centuries. This figure was calculated after one of the authors of the study, Kew scientist Rafaël Govaerts, reviewed all publications on plant extinctions over more than three decades and found the number to be four times more than the current listing of extinct plants. This new number is also more than twice the number of birds, mammals and amphibians recorded as extinct (a combined total of 217 species).

Dr Aelys M Humphreys, Author and Assistant Professor at the Department of Ecology, Environment and Plant Sciences at Stockholm University says: “Most people can name a mammal or bird that has become extinct in recent centuries, but few can name an extinct plant. This study is the first time we have an overview of what plants have already become extinct, where they have disappeared from and how quickly this is happening. We hear a lot about the number of species facing extinction, but these figures are for plants that we’ve already lost, so provide an unprecedented window into plant extinction in modern times.»

Reviewing these data, the scientists found that plant extinction is occurring much faster than ‘natural’ background rates of extinction (the normal rate of loss in earth’s history before human intervention), as much as 500 times faster. Animals are also disappearing much faster than background rates, at least 1000 times faster. The authors of the study believe these numbers underestimate the true levels of ongoing plant extinction.

The scientists found the highest rates of plant extinction to be on islands, in the tropics and in areas with a Mediterranean climate – typical biodiverse regions which are home to many unique species vulnerable to human activities. Authors Humphreys, Govaerts, Ficinski, Nic Lughadha and Vorontsova also found that plant species that are woody (such as trees and shrubs) and with a small geographical range (such as those confined to small islands) are more likely to be reported as extinct.  These results suggest that the increase in plant extinction rate could be due to the same factors that are documented as threats to many surviving plants: fragmentation and destruction of native vegetation resulting in the reduction or loss of habitat of many range-restricted species.

Why we should care that almost 600 species are extinct: Lessons we can learn from plant extinction

The information gathered from this analysis will be fundamental to help predict and prevent future extinction. Locality is more important for predicting future extinctions than identity — whether a plant occurs on an island or not is more helpful to predict extinction than whether the plant is a rose, orchid or palm. As change of land-use tends to wipe out most, if not all, the original plant inhabitants, irrespective of their characteristics, locality remains key to assessing future lives of plants and how we can protect them. This confirms the notion that ‘biodiversity hotspots’ – areas with exceptional numbers of endemic plants which are undergoing extensive habitat change – are key to understanding global patterns of recent and future extinctions.

Almost 600 plants have already gone extinct
The Chilean crocus, Tecophilaea cyanocrocus
[Credit: Richard Wilford]

Dr Eimear Nic Lughadha, Co-author and Conservation Scientist at Royal Botanic Gardens, Kew says: «Plants underpin all life on earth, they provide the oxygen we breathe and the food we eat, as well as making up the backbone of the world’s ecosystems – so plant extinction is bad news for all species. This new understanding of plant extinction will help us predict (and try to prevent) future extinctions of plants, as well as other organisms. Millions of other species depend on plants for their survival, humans included, so knowing which plants we are losing and from where, will feed back into conservation programmes targeting other organisms as well.”

Researchers at Kew and Stockholm University hope these data will be used to focus conservation efforts on islands and in the tropics, where plant loss is common, and in areas where less is known about plant extinction such as Africa and South America.

Dr Maria S Vorontsova, Co-author and Plant Taxonomist at Royal Botanic Gardens, Kew says: “To stop plant extinction, we need to record all the plants across the world – the naming of new species is a critical piece of the puzzle in the wider push to prioritise conservation of our precious natural world for generations to come. To do this we need to support herbaria and the production of plant identification guides, we need to teach our children to see and recognise their local plants and most importantly we need botanists for years to come.”

The plants lost to extinction

Many have heard of the famous examples of animal species that have become extinct in the last 250 years — the dodo, found on Mauritius until the 17th century, and the Yangtze River Dolphin, declared extinct as recently as 2006. Plants have also become extinct in the last two and a half centuries as this new study states but, because data are scarce and not comprehensively analysed before, few people are aware of the extent of the problem. Here are some examples of the plants that have disappeared from the wild:

The exploited sandalwood…

The Chile sandalwood, Santalum fernandezianum, was a tree that grew on the Juan Fernández Islands which lie between Chile and Easter island. From around 1624, the tree began to be heavily exploited for the aromatic sandalwood, and by the end of the 19th century most of the trees had been cut down.

The last tree was photographed on August 28, 1908 on Robinson Crusoe island by Carl Skottsberg. The tree has not been seen since on that island. Over the years there have been reports that the species was also to be found on Alejandro Selkirk island, though this has never been confirmed, and repeated searches have not found the species on that island either.

Extraordinary and extinct…

The banded trinity, Thismia americana, is possibly one of the most extraordinary plants ever to be discovered. It has no leaves and only the flowers are visible above ground. It was discovered in 1912 along Torrence Avenue in South Chicago. The site was, however, destroyed just five years later and this extraordinary plant was never seen again. Regular searches in remaining pockets of similar habitat in Chicago have been undertaken without success.

The plant belongs to a group (the genus Thismia) of 65 species which are nearly all from rainforests. A few species, including its closest relatives, extend into New Zealand. How a plant from New Zealand ended up in South Chicago will forever remain a mystery.

Gone but not forgotten…

The St Helena olive, Nesiota elliptica, was a tree first discovered in 1805 on the island of St Helena in the South Atlantic Ocean. Despite most of the original vegetation of the island having been destroyed, one lone elderly tree survived until 1994, from which Kew and local conservationists were able to collect cuttings from before it died.

Nesiota elliptica is the only species in the genus Nesiota, so that genus also disappeared with the extinction of the species in 2003.

Plants: lost and found

A positive from the paper’s analysis, was the evidence that 430 species once considered extinct have gone on to be rediscovered. Rediscovery of a species thought to be extinct often means finding a few surviving individuals only, and 90% of rediscovered plants still have a high extinction risk. Documenting rediscovery is important as it improves the accuracy of extinction records and allows for potential remedial conservation work too. Unfortunately, however, it does not usually mean that a species is ’alive and well‘, as the example of the Chilean crocus shows.

Popular Chilean bulb rediscovered in 2001 after years of searching…

The Chilean crocus, Tecophilaea cyanocrocus, is native in the hills above Santiago, the capital of Chile. It was a popular bulb with many colour variants grown by Victorian gardeners. To satisfy demand, large numbers of bulbs were dug up and imported from Chile as the species was difficult to grow and slow to propagate.

The species seemed to have vanished by the 1950s due to the over-collecting and grazing by livestock. After repeated searches, one small population was rediscovered in 2001 on private land south of Santiago. This species continues to be cultivated in Britain and its surviving native population is now being protected from livestock. It is categorised as ‘critically endangered’ on the International Union for Conservation of Nature (IUCN) Red List.

Source: Stockholm University [June 11, 2019]



Why Noah’s ark won’t work

A Noah’s Ark strategy will fail. In the roughest sense, that’s the conclusion of a first-of-its-kind study that illuminates which marine species may have the ability to survive in a world where temperatures are rising and oceans are becoming acidic.

Why Noah's ark won't work
Purple urchins are fortified with spines and shells. But new research led by UVM’s Melissa Pespeni shows
 that—to survive—they’ll need large populations that hold rare genetic variants, giving them
 a chance to adapt in a fast-warming world [Credit: Joshua Brown]

Two-by-two, or even moderately sized, remnants may have little chance to persist on a climate-changed planet. Instead, for many species, «we’ll need large populations,» says Melissa Pespeni a biologist at the University of Vermont who led the new research examining how hundreds of thousands of sea urchin larvae responded to experiments where their seawater was made either moderately or extremely acidic.

Rare Relief

Pespeni and her team were surprised to discover that rare variation in the DNA of a small minority of the urchins were highly useful for survival. These rare genetic variants are «a bit like having one winter coat among fifty lightweight jackets when the weather hits twenty below in Vermont,» Pespeni says.

«It’s that coat that lets you survive.» When the water conditions were made extremely acidic, these rare variants increased in frequency in the larvae. These are the genes that let the next generation of urchins alter how various proteins function—like the ones they use to make their hard-but-easily-dissolved shells and manage the acidity in their cells.

But to maintain these rare variants in the population—plus other needed genetic variation that is more common and allows for response to a range of acid levels in the water—requires many individuals.

«The bigger the population, the more rare variation you’ll have,» says Reid Brennan, a post-doctoral researcher in Pespeni’s UVM lab and lead author on the new study. «If we reduce population sizes, then we’re going to have less fodder for evolution—and less chance to have the rare genetic variation that might be beneficial.»

In other words, some organisms might persist in a climate-changed world because they’re able to change their physiology—think of sweating more; some will be able to migrate, perhaps farther north or upslope. But for many others, their only hope is to evolve—rescued by the potential for change that lies waiting in rare stretches of DNA.

Rapid Adaptation

The purple sea urchins the UVM team studied in their Vermont lab are part of natural populations that stretch from Baja, California to Alaska. Found in rocky reefs and kelp forests, these prickly creatures are a favorite snack of sea otters—and a key species in shaping life in the intertidal and subtidal zones.

Because of their huge numbers, geographic range, and the varying conditions they live in, the urchins have high «standing genetic variation,» the scientists note. This makes purple urchins likely survivors in the harsh future of an acidified ocean—and good candidates for understanding how marine creatures may adapt to rapidly changing conditions.

It is well understood that rising average global temperatures are a fundamental driver of the imminent extinction faced by a million or more species—as a recent UN biodiversity report notes. But it’s not just rising averages that matter. It may be the hottest—or most acidic—moments that test an organism’s limits and control its survival. And, as the UVM team writes, «the genetic mechanisms that allow rapid adaptation to extreme conditions have been rarely explored.»

Currency in the Current Sea

The new study used an innovative «single-generation selection» experiment that began with twenty-five wild-caught adult urchins. Each female produced about 200,000 eggs from which the scientists were able extract DNA out of pools of about 20,000 surviving larvae that were living in differing water conditions. This very large number of individuals gave the scientists a clear view that purple urchins possess a genetic heritage that lets them adapt to extremely acidic ocean water.

«This species of sea urchin is going to be okay in the short term. They can respond to these low pH conditions and have the needed genetic variation to evolve,» says UVM’s Reid Brennan. «So long as we do our part to protect their habitats and keep their populations large.»

But coming through the ferocious challenge of rapid climate change may come at a high cost. «It’s hopeful that evolution happens—and it’s surprising and exciting that these rare variants play such a powerful role,» says Melissa Pespeni, an assistant professor in UVM’s biology department and expert on ocean ecosystems. «This discovery has important implications for long-term species persistence. These rare variants are a kind of currency that urchins have to spend,» she says. «But they can only spend it once.»

The study was published in the Proceedings of the Royal Society B.

Author: Joshua E. Brown | Source: University of Vermont [June 11, 2019]



Tube anemone has the largest animal mitochondrial genome ever sequenced

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs. The human mitochondrial genome (mitogenome), for example, comprises 16,569 base pairs.

Tube anemone has the largest animal mitochondrial genome ever sequenced
Discovery by Brazilian and US researchers could change the classification of two species,
which appear more akin to jellyfish than was thought [Credit: Sérgio Stampar]

Tube anemones (Ceriantharia) are the focus of an article recently published in Scientific Reports describing the findings of a study led by Sérgio Nascimento Stampar, a professor in São Paulo State University’s School of Sciences and Letters (FCL-UNESP) at Assis in Brazil.

The study was supported by FAPESP via a regular grant for the project «Evolution and diversity of Ceriantharia (Cnidaria» and via its program São Paulo Researchers in International Collaboration (SPRINT) under a cooperation agreement with the University of North Carolina (UNC) at Charlotte in the US.

The mitogenome is simpler than the nuclear genome, which in the case of I. nocturnus has not yet been sequenced, Stampar explained. The human nuclear genome comprises some 3 billion base pairs, for example. Another discovery reported in the article is that I. nocturnus and Pachycerianthus magnus (another species studied by Stampar’s group, 77,828 base pairs) have linear genomes like those of medusae (Medusozoa), whereas other species in their class (Anthozoa) and indeed most animals have circular genomes.

I. nocturnus is found in the Atlantic from the coast of Patagonia in Argentina as far north as the East Coast of the US. P. magnuslives in the marine environment around the island of Taiwan in Asia. Both inhabit waters at most 15 m deep.

«I. nocturnus’s mitogenome is almost five times the size of the human mitogenome,» Stampar said. «We tend to think we’re molecularly more complex, but actually our genome has been more ‘filtered’ during our evolution. Keeping this giant genome is probably more costly in terms of energy expenditure.»

The shape of the mitogenomes in these two species of tube anemone and the gene sequences they contain were more surprising than their size.

Because they are closely related species, their gene sequences should be similar, but I. nocturnus has five chromosomes while P. magnus has eight, and each has a different composition in terms of genes. This kind of variation had previously been found only in medusozoans, sponges, and some crustaceans.

«Humans and bony fish species are more similar than these two tube anemones in terms of the structure of their mitochondrial DNA,» Stampar said.

São Paulo coast and South China Sea

To arrive at these results, the researchers captured specimens in São Sebastião, which lies on the coast of São Paulo State in Brazil, and off Taiwan in the South China Sea. Small pieces of the animals’ tentacles were used to sequence their mitogenomes.

The genomes of the two species hitherto available from databases were incomplete owing to the difficulty of sequencing them. After completing the study, the researchers published the genomes by gifting them to GenBan, a database maintained in the US by the National Center for Biotechnology Information (NCBI) at the National Institutes of Health (NIH).

Another obstacle to sequencing was the difficulty of collecting these animals because of their elusive behavior. In response to any potential threat, a tube anemone hides in the long leathery tube that distinguishes it from true sea anemones, making capture impossible.

«You have to dig a hole around it, sometimes as deep as a meter, and stop up the part of the tube buried in sand. All this must be done under water while carrying diving gear. Otherwise, it hides in the buried part of the tube and you simply can’t get hold of it,» Stampar said.

Thanks to the support of FAPESP’s SPRINT program, Stampar and Marymegan Daly, a research colleague at Ohio State University in the US, established a partnership with Adam Reitzel and Jason Macrander at UNC Charlotte. Macrander, then a postdoctoral researcher under Reitzel, is a professor at Florida Southern College.

Reitzel and Macrander specialize in the use of bioinformatics to filter genomics data and assemble millions of small pieces of mitochondrial DNA into a single sequence. They used this technique to arrive at complete mitochondrial genomes for both species.

«In this technique, you sequence bits of the genome and link them in a circle. The problem is that this only works with circular genomes. Because we couldn’t find a piece to close the circle, we realized the genome had to be linear, as it is for Medusozoa,» Stampar said.

The discovery makes way for a possible reclassification of cnidarian species (hydras, medusae, polyps, corals and sea anemones). The tube anemones studied appear to form a separate group from corals and sea anemones and display some similarities to medusae.

However, more data will be needed before a definitive conclusion can be reached. The necessary data could come from the sequencing of these species’ nuclear genomes, which Stampar and his group intend to complete by the end of 2019.

Author: André Julião | Source: FAPESP [June 11, 2019]



Traces of Roman temple found in Lisbon

An archaeological intervention in Rua da Saudade led to the discovery of remains that are interpreted as belonging to the floor of a Roman temple, according to an announcement by the Lisbon Museum. This is the first discovery of its kind in Lisbon.

Traces of Roman temple found in Lisbon
Credit: © DR

The archaeological intervention that resulted in the discovery of the floor took place in a private building with the aim of «of transforming the interior» of a ground floor into a garage.
«Given the proximity to the Roman theatre, a listed heritage monument, the team of the Museum of Lisbon-Roman Theatre carried out the excavation work necessary for the implementation of the new engineering project, which is mandatory whenever places of potential archaeological value located,» explained the organization in a statement.

Traces of Roman temple found in Lisbon
Credit: © DR

Lidia Fernandes, coordinator of the Roman Theatre, explained what was found on Rua da Saudade: «Actually, it cannot be said that we found the floor. What was preserved is less impressive but much more curious. What we found were the perfectly preserved impressions left by the stone slabs in the still fresh mortar, when the stones were placed. The geometric motifs that the slabs formed were quite elaborate, integrating central motifs delimited by rectangular panels», said the statement.
«Not knowing which stones were used we were lucky that the Roman masons had taken advantage of the leftover pieces of the slabs to level the ground where the panels were placed. At present, we have identified more than 30 ‘lithotypes’, that is, different types of stone,» said the archaeologist.

Traces of Roman temple found in Lisbon
Credit: © DR

Although the flooring of the Roman period is «quite diversified», what was found in Lisbon is not very common. In Portugal, few examples of the opus sectile are known and, in Lisbon, the only one that is preserved is the Roman Theatre. However, what has now been found is «much more interesting» than the latter, since «the motifs are more elaborate and the types of stone more diverse».
Opus sectile is an architectural ornamentation technique where materials were cut into geometric, vegetable or figurative shapes and inlaid into walls and floors to make ornamental compositions.

Traces of Roman temple found in Lisbon
Credit: © DR

Taking into account the location of the new discovery, and also taking into account the identification of another structure in the adjoining building (to the east) by Irisalva Moita in 1987, the interpretation of this as a Roman temple is likely.

«Several temples once existed in the city of Felicitas Iulia Olisipo; this, however, is the first with archaeological evidence,» said Lidia Fernandes.

Source: Publico [June 11, 2019]



Roman Shrine to Nemesis, Chester Roman Amphitheatre, Chester, Cheshire, 15.6.19.

Roman Shrine to Nemesis, Chester Roman Amphitheatre, Chester, Cheshire, 15.6.19.

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2019 June 16 Unusual Mountain Ahuna Mons on Asteroid Ceres…

2019 June 16

Unusual Mountain Ahuna Mons on Asteroid Ceres
Image Credit: Dawn Mission, NASA, JPL-Caltech, UCLA, MPS/DLR/IDA

Explanation: What created this unusual mountain? There is a new theory. Ahuna Mons is the largest mountain on the largest known asteroid in our Solar System, Ceres, which orbits our Sun in the main asteroid belt between Mars and Jupiter. Ahuna Mons, though, is like nothing that humanity has ever seen before. For one thing, its slopes are garnished not with old craters but young vertical streaks. The new hypothesis, based on numerous gravity measurements, holds that a bubble of mud rose from deep within the dwarf planet and pushed through the icy surface at a weak point rich in reflective salt – and then froze. The bright streaks are thought to be similar to other recently surfaced material such as visible in Ceres’ famous bright spots. The featured double-height digital image was constructed from surface maps taken of Ceres in 2016 by the robotic Dawn mission. Successfully completing its mission in 2018, Dawn continues to orbit Ceres even though it has exhausted the fuel needed to keep its antennas pointed toward Earth.

∞ Source: apod.nasa.gov/apod/ap190616.html

Chester Roman Amphitheatre, Chester, Cheshire, 15.6.19.

Chester Roman Amphitheatre, Chester, Cheshire, 15.6.19.

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Not Bell Beaker, not Corded Ware, but…the SGBR complex

If anyone can explain to me what this new paper at the Proceedings of the Prehistoric Society journal is actually about I’d be very grateful.

Furholt, Martin, Re-integrating Archaeology: A Contribution to aDNA Studies and the Migration Discourse on the 3rd Millennium BC in Europe, Proceedings of the Prehistoric Society, Published online: 10 June 2019, DOI: https://doi.org/10.1017/ppr.2019.4
See also…


Who will be the first woman on the Moon?

NASA logo.

June 15, 2019

For the return to the moon decreed by Donald Trump, NASA promised that there would be an astronaut. Several candidates are favorites.

Anne McClain, a former army helicopter pilot, is one of the favorites. Image Credit: NASA

Twelve women are astronauts at NASA. The suspense is complete, but the woman who will walk on the Moon in 2024 is probably one of them. They are between 40 and 54 years old. They are former military pilots, doctors or PhDs, recruited from thousands by the US Space Agency since the late 1990s.

The twelve astronaut women of NASA. Image Credit: NASA

Predicting which will be chosen to join Neil Armstrong in the history books is impossible, but for several former astronauts and experts, the proximity of the deadline will force NASA to select one of twelve, rather than future beginners.

«I would not be opposed to sending a rookie. But there are enough astronauts who have already flown, who already know how they react in space, «says Eileen Collins, a former astronaut, who flew and commanded the Space Shuttle in the 1990s and 2000s.

«It would be better to send people who have already made at least one flight,» said Ken Bowersox, a senior Nasa official. It will be all the easier as they have never been so numerous.

In the beginning, NASA only recruited soldiers and therefore men. The twelve astronauts who walked on the moon between 1969 and 1972 were all men. The first American in space was Sally Ride, in 1983. For the return to the moon decreed by Donald Trump, the program «Artemis», NASA promised that there would be an astronaut.

Anne, Christina, Jessica, Nicole

The four women of the 21st «promotion», recruited in 2013, will represent a good balance between youth and experience. Aged 40 or 41 today, they will each have made their first space stay by 2020.

Anne McClain, former helicopter pilot of the Army, is until end of June in the International Space Station (ISS). An assured look, a clear word, a slight smile: all his being expresses the ineffable «stuff of heroes», this tranquil force of character of the original recruits of NASA.

In the closed room of ISS also floats Christina Koch, engineer and passionate climbing. It will beat, with eleven months, the record of the longest female stay in space.

The duo almost made the first 100% female spacewalk, but a combination problem forced Anne McClain to give way to Nick Hague. «Christina Koch and Anne McClain are my two favorites,» says Janet Ivey, host of a children’s space show and board member of the National Space Society.

But their two classmates, marine biologist specialist of penguins and geese Jessica Meir and former F/A-18 test pilot  Nicole Mann, who participated in the wars in Iraq and Afghanistan, will be all also qualified: they are in full training to go to the ISS. In an interview in 2016, the four declared themselves to be volunteers for Mars if the opportunity arose. We can imagine them refusing the moon.

«Opaque» procedure

There is no age for space, they say to NASA. The mythical John Glenn had revolished at 77 years. Nothing therefore excludes the oldest astronaut, Sunita Williams, who is preparing his third space flight and will be 58 in 2024.

Especially since «Nasa has always appreciated the leadership qualities of the test pilots,» says Kent Rominger, head of the astronaut’s office from 2002 to 2006. «Suni» has flown about 30 aircraft in his military career.

Two other women, Serena Aunon-Chancellor and Kate Rubins, flew recently. Five women have not flown since at least 2010, but remain active.

Woman on the Moon (unknown source)

In the promotion recruited in 2017, there are five women, but their initial training is still not completed. They are not automatically excluded, but the schedule is unfavorable to them, especially as NASA tends to respect the order of seniority, notes Michael Lopez-Alegria, a former astronaut who spent 20 years at the agency.

In the end, the selection process «is quite opaque,» he says, with experience. In Houston, the chief astronaut will be keen to compose a team whose profiles will be complementary, between ex-military and scientific, and between different personalities. The mission should have four crew members, two of whom will descend on the moon. Why not two women.

National Aeronautics and Space Administration (NASA): https://www.nasa.gov/

Images (mentioned), Text, Credits: AFP/Orbiter.ch Aerospace/Roland Berga.

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Growing in 3D Survival from bowel cancer has doubled in the UK…

Growing in 3D

Survival from bowel cancer has doubled in the UK over the past 40 years, and more than half of all patients will be alive ten years after diagnosis. Some tumours are still hard to treat, particularly once they’ve spread around the body and evolved resistance to chemotherapy. One solution is to use combinations of multiple drugs, tested on pure populations of cancer cells grown in flat layers in the lab. But people are not Petri dishes, and the results in patients have been disappointing. Researchers are now growing three-dimensional ‘mini-guts’ (organoids) like this one, combining bowel cancer cells from patients with other types of cells that are normally found in tumours. Dead cells (stained red) can be seen amongst the survivors (green) after three days of treatment with a three drug combo – a technique that could be used for personalised testing to find the right combination for each patient.

Written by Kat Arney

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Hematite | #Geology #GeologyPage #Mineral Locality: Rio Marina,…

Hematite | #Geology #GeologyPage #Mineral

Locality: Rio Marina, Elba, Tuscany, Italy

Size: 3.1 × 2.5 × 2 cm

Photo Copyright © Piatek Minerals /e-rocks com

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Proustite | #Geology #GeologyPage #Mineral Locality:…

Proustite | #Geology #GeologyPage #Mineral

Locality: Chanarcillo, Copiapo Province, Atacama Region, Chile, South America

Dimensions: 2.8 × 2.1 × 1.9 cm

Photo Copyright © Crystal Classics

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https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...