четверг, 17 октября 2019 г.

Prehistoric Pottery, The Potteries Museum and Gallery, Stoke on Trent, 5.10.19.











Prehistoric Pottery, The Potteries Museum and Gallery, Stoke on Trent, 5.10.19.


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Human Skull (likely Romano British) found in Old Hannah’s Cave, The Potteries...


Human Skull (likely Romano British) found in Old Hannah’s Cave, The Potteries Museum and Gallery, Stoke on Trent, 5.10.19.


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The Staffordshire Moorlands Pan, a Roman bowl recording a visit to Hadrian’s Wall,...





The Staffordshire Moorlands Pan, a Roman bowl recording a visit to Hadrian’s Wall, The Potteries Museum and Gallery, 5.10.19.


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Seize the Moment Contrary to what you might expect, the fruit…


Seize the Moment


Contrary to what you might expect, the fruit fly seizure gene normally prevents nerve cells from becoming over-excited and triggering seizures. But when the gene is faulty, flies suffer from stress-induced seizures. Humans also have a version of seizure known as hERG, and people with a fault in the gene have a higher risk of a heart problem called long QT syndrome, which causes an irregular heartbeat, fainting, seizures and can even be fatal. By carefully studying seizure in fruit flies, researchers have found that faults in the gene affect the insects’ brains but not their hearts. These images show various parts of the fly brain, with cells where seizure is active highlighted in green and other types of nerve cells coloured pink and blue. The results suggest that seizures associated with long QT syndrome may be due to the lack of hERG in the brain, rather than the heart.


Written by Kat Arney



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The giant geode of Pulpi

The geode of Pulpi is an 11-meter hollow ovoid with crystal-paneled walls. It is like those familiar couplets of stone interiors covered with bright crystallites, but so large that several people can fit inside. The crystals, of up to two meters in size, are so transparent that they look like ice crystals. In this paper for Geology, Juan Manuel Garcia-Ruiz and colleagues reveal the geological history that ended with the formation of the Pulpi geode.











The giant geode of Pulpi
The geode of Pulpi [Credit: Hector Garrido]

Like the giant crystals of Naica in Mexico (see the 2007 Geology article by Garcia-Ruiz and colleagues), the crystals of Pulpi are gypsum (calcium sulfate with two water molecules). Garcia-Ruiz says, «To reveal their formation has been a very tough task because unlike in the case of Naica, where the hydrothermal system is still active, the large geode of Pulpi is a fossilized environment.»
The team performed a study of the geology and geochemistry of the abandoned mine where the geode was found, including a detailed mapping of the underground mining works, which has been used to allow the tourist visits in the mine.











The giant geode of Pulpi
The Mina Rica in the Sierra del Aguilon, Pulpi, Almeria
[Credit: Javier Trueba]

They found that the crystals of Pulpi formed at around 20 °C, at a shallow depth where the temperature fluctuations of the climate are still perceptible. These temperature fluctuations, being below the maximum solubility of gypsum (40 °C), led to the dissolution and recrystallization amplifying a maturation process that is known as Ostwald maturation.
Says Garcia-Ruiz, «This is somewhat like the temperature cycles in crystal quality control in industrial processes.» A continuous supply of salt for the formation of the crystals was provided by the dissolution of anhydrite (the anhydrous form of calcium sulfate), the mechanism accounting for the formation of the large crystals of Naica.


Because of their purity, the crystals forming the geode cannot be dated precisely. But indirect constraint can be done: «They grew for sure after the desiccation of the Mediterranean Sea that occurred 5.6 million years ago. They are most probably younger than two million years but older than 60.000 years because this is the age of the carbonate crust coating one of the large gypsum crystal,» says Garcia-Ruiz.


Source: Geological Society of America [October 15, 2019]



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Geologists reveal anoxia caused loss in biodiversity in ancient seas

Since 2016 the researchers of the Department of Geology at Tallinn University of Technology have been engaged in a research project analysing the causes of Silurian biodiversity crisis. The findings of the study are summarized in the article «Linking the progressive expansion of reducing conditions to a stepwise mass extinction event in the late Silurian oceans» published recently in the journal Geology.











Geologists reveal anoxia caused loss in biodiversity in ancient seas
Eurypterus, a common Upper Silurian eurypterid
[Credit: WikiCommons]

The international research team included scientists from the University of Florida, Tallinn University of Technology, the University of South Carolina and Lund University. A member of the research group, Professor of Bedrock Geology at Tallinn University of Technology Olle Hints says, «Our research focused on the changes in the Earth’s environmental conditions and biodiversity during the Silurian period, ca 425 million years ago».


Five big mass extinctions are known from the last half a billion years of Earth’s history. For example, 250 million years ago, at the end of the Permian period, 95% of the plant and animal species of that time disappeared in a short time. Today, too, we are facing major biodiversity loss and knowledge of past extinction events enables us to assess its potential course and consequences. In severe biotic crisis in the Silurian, known as the Lau Event, extinction of nearly 25% of the marine species took place. The scientists set out to determine the chronology and possible mechanisms of the event.


Information on the biota and environment of the distant past is best preserved in marine sedimentary rocks. Study of fossils enables us to document the evolution and biodiversity dynamics. Fossils also play a crucial role in constructing the geologic time scale and dating rocks. Only if precise time scale is available can it be investigated how and why environmental conditions changed and how this influenced the biosphere. For example, the atoms making up the minerals of limestone provide the evidence of the chemical composition of the ancient ocean and the atmosphere and their evolution. By combining paleontological and geochemical data, conclusions can be drawn about the relationships between biota and the environment.


In this work, the researchers focused on the study of carbon, sulphur and thallium isotopes. «What makes our research unique is that for the first time, thallium isotopes were analysed from the Paleozoic rocks indicating changes in redox conditions of the global ocean. The rock samples analysed were collected from Latvia and the island of Gotland, which once were part of the Baltic paleosea. In this region, rocks have altered very little over the last 500 million years, and thus the original information is still present. The Baltic region is a rewarding natural laboratory for geologists — there are very few places in the world where the rocky archives of the Paleozoic era are so well preserved,» professor Hints says.











Geologists reveal anoxia caused loss in biodiversity in ancient seas
PhD student Chelsie N. Bowman and Professor Seth A. Young from the Florida State University collecting samples
from the 425 million years old Earth history archives that are deposited at Tallinn University of Technology
[Credit: Olle Hints]

This fact ensures that the results of the analyses are reliable. Alongside the unique rock samples, the cutting-edge analytical equipment that makes it possible to measure stable isotope ratios from small amounts of rock powders played a crucial role. Most of the geochemical analyses were carried out by Chelsie N. Bowman and Professor Seth A. Young in the National High Magnetic Field Laboratory at Florida State University, one of the most modern analytical facilities for this kind of research in the world.
The results of the analyses showed for the first time that the extinction of late Silurian species began with a progressive decrease in the oxygen content in the ocean and culminated when anoxic and likely sulphidic water masses reached the shallow seas. This change was relatively slow — it took probably 175-270 k.y. from the the initial phase until the crisis reached its peak. Among the first organisms to suffer from the environmental change were there vertebrates, represented by fish and conodonts, whose diversity decreased by nearly 70%. The environmental change had also a major impact on plankton, although it occurred somewhat later.


Professor Hints said, «What are the benefits of studying such a distant past? On the one hand, we can confirm that changes in marine redox conditions and oxygen levels have catastrophic consequences for the life in oceans and that the vertebrates are the first to be affected by the changes.» This is a highly topical issue since measurements as well as models indicate progressive expansion of oceanic anoxia in the present-day oceans. Geological data prove that if a system is shifted out of equilibrium, it will take hopelessly long time from human perspective in order to return to the pre-event conditions.


«On the other hand, we can learn from this particular example, as well as from the Earth history in general, that every crisis creates the basis for evolutionary innovations, allowing better adaptable organisms to survive and new ones to emerge,» Professor Hints says.


Source: Estonian Research Council [October 15, 2019]



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Cache of sealed coffins discovered in necropolis on Luxor’s West Bank

Egypt’s Antiquities Ministry says archaeologists have uncovered at least 20 ancient wooden coffins in the southern city of Luxor.











Cache of sealed coffins discovered in necropolis on Luxor's West Bank
This photo provided by the Egyptian Ministry of Antiquities shows recently discovered ancient coloured coffins with
inscriptions and paintings, in the southern city of Luxor, Egypt [Credit: Egypt. Ministry of Antiquities via AP]

A brief statement from the ministry says Tuesday says archaeologists found the coffins in the Asasif Necropolis. The necropolis, located in the ancient town of West Thebes, includes tombs dating back to the Middle, New Kingdom and the Late Periods (1994 BC to 332 BC).


Cache of sealed coffins discovered in necropolis on Luxor's West Bank


Cache of sealed coffins discovered in necropolis on Luxor's West Bank










Cache of sealed coffins discovered in necropolis on Luxor's West Bank
The ministry said archeologists found at least 20 wooden coffins in the Asasif Necropolis, describing it as one of the
«biggest and most important» discoveries in recent years [Credit: Egypt. Ministry of Antiquities via AP]

Photos from the ministry show coloured coffins with inscriptions and paintings. The ministry described it as one of the «biggest and most important» discoveries in recent years.


The ministry says it will release further details at a news conference on Saturday.


Egypt has sought publicity for its archaeological discoveries in the hopes of reviving its tourism sector, which was badly hit by the turmoil following the 2011 uprising.


Source: The Associated Press [October 15, 2019]



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New study shows huge dinosaurs evolved different cooling systems to combat heat stroke

Different dinosaur groups independently evolved gigantic body sizes, but they all faced the same problems of overheating and damaging their brains. Researchers from Ohio University’s Heritage College of Osteopathic Medicine show in a new article in the Anatomical Record that different giant dinosaurs solved the problem in different ways, evolving different cooling systems in different parts of the head.











New study shows huge dinosaurs evolved different cooling systems to combat heat stroke
Gigantic dinosaurs like the sauropod Diplodocus, which weighed over 15 tons and was longer than an 18-wheeler truck,
 would have had problems with potentially lethal overheating. Hot blood from the body core would have been pumped
 to the head, damaging the delicate brain. New research shows that in sauropods, evaporation of moisture in the nose
and mouth would have cooled extensive networks of venous blood destined for the brain. Other large dinosaurs
 evolved different brain-cooling mechanisms, but all involving evaporative cooling of blood in
different regions of the head [Credit: Michael Skrepnick, WitmerLab, Ohio University]

«The brain and sense organs like the eye are very sensitive to temperature,» said Ruger Porter, Assistant Professor of Anatomical Instruction and lead author of the study. «Animals today often have elaborate thermoregulatory strategies to protect these tissues by shuttling hot and cool blood around various networks of blood vessels. We wanted to see if dinosaurs were doing the same things.»


Many of the famous gigantic dinosaurs — such as the long-necked sauropods or armored ankylosaurs— actually evolved those big bodies independently from smaller-bodied ancestors. «Small dinosaurs could have just run into the shade to cool off,» said study co-author Professor Lawrence Witmer, «but for those giant dinosaurs, the potential for overheating was literally inescapable. They must have had special mechanisms to control brain temperature, but what were they?»


The answer turned out to be based in physics, but still part of our everyday experience. «One of the best ways to cool things down is with evaporation,» Porter said. «The air-conditioning units in buildings and cars use evaporation, and it’s the evaporative cooling of sweat that keeps us comfortable in summer. To cool the brain, we looked to the anatomical places where there’s moisture to allow evaporative cooling, such as the eyes and especially the nasal cavity and mouth.»


To test that idea, the team looked to the modern-day relatives of dinosaurs — birds and reptiles — where studies indeed showed that evaporation of moisture in the nose, mouth, and eyes cooled the blood on its way to the brain.


Porter and Witmer obtained carcasses of birds and reptiles that had died of natural causes from zoos and wildlife rehabilitation facilities. Using a technique developed in Witmer’s lab that allows arteries and veins to show up in CT scans, they were able to trace blood flow from the sites of evaporative cooling to the brain. They also precisely measured the bony canals and grooves that conveyed the blood vessels.


«The handy thing about blood vessels is that they basically write their presence into the bones,» Porter said. «The bony canals and grooves that we see in modern-day birds and reptiles are our link to the dinosaur fossils. We can use this bony evidence to restore the patterns of blood flow in extinct dinosaurs and hopefully get a glimpse into their thermal physiology and how they dealt with heat.»


«The discovery that different dinosaurs cooled their brains in a variety of ways not only provides a window into the everyday life of dinosaurs, it also serves as an exemplar of how the physical constraints imposed by specific environmental conditions have shaped the evolution of this diverse and unique group,» said Sharon Swartz, a program director at the National Science Foundation, which funded the research. «Using a combination of technological innovation and biological expertise, these researchers were able to take a direct reading from the fossil record that provides new clues about how dinosaur skeletal form and function evolved.»











New study shows huge dinosaurs evolved different cooling systems to combat heat stroke
Recent research by Porter and Witmer has shown that different dinosaur groups had different thermal physiological
 strategies to help moderate brain temperatures in the face of high heat loads. Evaporatively cooled blood in
different sites of heat exchange was shuttled to the brain region to help moderate brain temperatures. This 3D
 model generated by Ryan Ridgely replicates the content of Figure 1 of Porter & Witmer (2019). Small-bodied
dinosaurs like Stegoceras had a balanced pattern of blood supply with no particular emphasis on any one
site of heat exchange whereas larger-bodied dinosaurs had a more focused thermal strategy, emphasizing
blood flow to the nasal region (Euoplocephalus), oral & nasal regions (Camarasaurus), or the antorbital
air sinus (Majungasaurus). Development of focused thermal strategies is associated with the evolution
of large body sizes [Credit: WitmerLab, Ohio University]

This team of current and former members of WitmerLab at Ohio University has previously looked at other cases of dinosaur physiology. In 2014 and 2018, former doctoral student Jason Bourke led projects involving Porter and Witmer on breathing and heat exchange in pachycephalosaurs and ankylosaurs, respectively. Most recently, former lab doctoral student Casey Holliday led a project with Porter and Witmer that explored blood vessels on the skull roof of T. rex and other dinosaurs that also might have had a thermoregulatory function.


The new study by Porter and Witmer is a more expansive, quantitative study that shows that «one size didn’t fit all» with regard to how large-bodied dinosaurs kept their brains cool. That is, they had different thermoregulatory strategies. The researchers looked at bony canal sizes in the dinosaurs to assess the relative importance of the different sites of evaporative cooling based on how much blood was flowing through them.


A key factor turned out to be body size. Smaller dinosaurs such as the goat-sized pachycephalosaur Stegoceras had a very balanced vascular pattern with no single cooling region being particularly emphasized. «That makes physiological sense because smaller dinosaurs have less of a problem with overheating,» Porter said. «But giants like sauropods and ankylosaurs increased blood flow to particular cooling regions of the head far beyond what was necessary to simply nourish the tissues.» This unbalanced vascular pattern allowed the thermal strategies of large dinosaurs to be more focused, emphasizing one or more cooling regions.


But although sauropods like Diplodocus and Camarasaurus and ankylosaurs like Euoplocephalus all had unbalanced vascular patterns emphasizing certain cooling regions, they still differed. Sauropods emphasized both the nasal cavity and mouth as cooling regions whereas ankylosaurs only emphasized the nose. «It’s possible that sauropods were so large — often weighing dozens of tons — that they needed to recruit the mouth as a cooling region in times of heat stress,» Porter said. «Panting sauropods may have been a common sight!»


One problem that the researchers encountered was that many of the theropod dinosaurs — such as the 10-ton T. rex — were also gigantic, but the quantitative analysis showed that they had a balanced vascular pattern, like the small-bodied dinosaurs.


«This finding had us scratching our heads until we noticed the obvious difference—theropods like Majungasaurus and T. rex had a huge air sinus in their snouts,» Witmer said. Looking closer, the researchers discovered bony evidence that this antorbital air sinus was richly supplied with blood vessels. Witmer had previously shown that air circulated through the antorbital air sinus like a bellows pump every time the animal opened and closed its mouth. «Boom! An actively ventilated, highly vascular sinus meant that we had another potential cooling region. Theropod dinosaurs solved the same problem…but in a different way,» concluded Witmer.


The researchers are now expanding the project to include other dinosaur groups such as duck-billed hadrosaurs and horned ceratopsians like Triceratops to explore how thermoregulatory strategies varied among other dinosaurs and how these strategies may have influenced their behavior and even their preferred habitats.


Source: Ohio University [October 16, 2019]



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Early humans travelled to Greek islands tens of thousands of years earlier than believed

An international research team led by scientists from McMaster University has unearthed new evidence in Greece proving that the island of Naxos was inhabited by Neanderthals and earlier humans at least 200,000 years ago, tens of thousands of years earlier than previously believed.











Early humans travelled to Greek islands tens of thousands of years earlier than believed
‘Neanderthals on Naxos!’ [Credit: Kathryn Killackey]

The findings, published in the journal Science Advances, are based on years of excavations and challenge current thinking about human movement in the region—long thought to have been inaccessible and uninhabitable to anyone but modern humans. The new evidence is leading researchers to reconsider the routes our early ancestors took as they moved out of Africa into Europe and demonstrates their ability to adapt to new environmental challenges.
«Until recently, this part of the world was seen as irrelevant to early human studies but the results force us to completely rethink the history of the Mediterranean islands,» says Tristan Carter, an associate professor of anthropology at McMaster University and lead author on the study. He conducted the work with Dimitris Athanasoulis, head of archaeology at the Cycladic Ephorate of Antiquities within the Greek Ministry of Culture.











Early humans travelled to Greek islands tens of thousands of years earlier than believed
Geological hand sample of Stelida chert [Credit: Nikos Skarpelis]

While Stone Age hunters are known to have been living on mainland Europe for over 1 million years, the Mediterranean islands were previously believed to be settled only 9,000 years ago, by farmers, the idea being that only modern humans — Homo sapiens — were sophisticated enough to build seafaring vessels.


Scholars had believed the Aegean Sea, separating western Anatolia (modern Turkey) from continental Greece, was therefore impassable to the Neanderthals and earlier hominins, with the only obvious route in and out of Europe was across the land bridge of Thrace (southeast Balkans).











Early humans travelled to Greek islands tens of thousands of years earlier than believed
Reconstruction of prehistoric spearheads being made at Stelida – of Lower, Middle and Upper Palaeolithic,
plus Mesolithic date (L-R) [Credit: Kathryn Killackey]

The authors of this paper suggest that the Aegean basin was in fact accessible much earlier than believed. At certain times of the Ice Age the sea was much lower exposing a land route between the continents that would have allowed early prehistoric populations to walk to Stelida, and an alternative migration route connecting Europe and Africa. Researchers believe the area would have been attractive to early humans because of its abundance of raw materials ideal for toolmaking and for its fresh water.
At the same time however, «in entering this region the pre-Neanderthal populations would have been faced with a new and challenging environment, with different animals, plants and diseases, all requiring new adaptive strategies,» says Carter.











Early humans travelled to Greek islands tens of thousands of years earlier than believed
A researcher works at a trench at Stelida (Naxos, Greece)
[Credit: Evaggelos Tzoumenekas]

In this paper, the team details evidence of human activity spanning almost 200,000 years at Stelida, a prehistoric quarry on the northwest coast of Naxos. Here early Homo sapiens, Neanderthals and earlier humans used the local stone (chert) to make their tools and hunting weapons, of which the team has unearthed hundreds of thousands.


Reams of scientific data collected at the site add to the ongoing debate about the importance of coastal and marine routes to human movement. While present data suggests that the Aegean could be crossed by foot over 200,000 years ago, the authors also raise the possibility that Neanderthals may also have fashioned crude seafaring boats capable of crossing short distances.



This research is part of the Stelida Naxos Archeological Project, a larger collaboration involving scholars from all over the world. They have been working at the site since 2013.


Source: McMaster University [October 16, 2019]



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Surveying solar storms by ancient Assyrian astronomers

A research team led by the University of Tsukuba combined observations from ancient cuneiform tablets that mention unusual red skies with radioisotope data to identify solar storms that likely occurred around 679 to 655 BCE, prior to any previously datable events. This work may help modern astronomers predict future solar flares or coronal mass ejections that can damage satellite and terrestrial electronic devices.











Surveying solar storms by ancient Assyrian astronomers
Credit: Cambridge Alert

Humans have been looking to the skies for as long as we have been around. Some of the observations made by ancient Assyrian and Babylonian astrologers more than two millennia ago survive in the form of cuneiform records. These rectangular clay tablets were messages from professional scholars to kings who had commissioned astronomical observations for the purpose of discerning omens—including comets, meteors, and planetary motions.


Now, a team led by the University of Tsukuba has matched three of these ancient tablets that mention an unusual red glow in the sky with the carbon-14 concentrations in tree rings and demonstrate how they are evidence of solar magnetic storms.


These observations were made approximately 2,700 years ago in Babylon and the Assyrian city of Nineveh, both of which are mentioned contemporaneously in the Bible. For example, one tablet says, «red covers the sky,» while another mentions a «red cloud.» These were probably manifestations of what we call today stable auroral red arcs, consisting of light emitted by electrons in atmospheric oxygen atoms after being excited by intense magnetic fields.


While we usually think of aurorae as confined to northern latitudes, during periods of strong magnetic activity, as with a solar mass ejection, they may be observed much further south. Moreover, because of changes in the Earth’s magnetic field over time, the Middle East was closer to the geomagnetic pole during this period in history.


«Although the exact dates of the observations are not known, we were able to narrow the range considerably by knowing when each astrologer was active,» co-first author Yasuyuki Mitsuma says. Based on tree-ring samples, there was a rapid rise in radioactive carbon-14 in the environment during this time, which is associated with increased solar activity.


«These findings allow us to recreate the history of solar activity a century earlier than previously available records,» explains Mitsuma. «This research can assist in our ability to predict future solar magnetic storms, which may damage satellites and other spacecraft.»


The study is published in The Astrophysical Journal.


Source: University of Tsukuba [October 16, 2019]



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NASA Announces Changes to Spacewalk Schedule, First All-Female Spacewalk


EVA — Extra Vehicular Activities patch.


Oct. 17, 2019


NASA is hosting a media teleconference at 4:30 p.m. EDT today to discuss this week’s first all-female spacewalk at the International Space Station. Audio of the teleconference will stream live on the agency’s website: https://www.nasa.gov/live


Kenny Todd, manager of International Space Station Operations Integration, and Megan McArthur, deputy chief of NASA’s Astronaut Office, will talk to and take questions from media about recent changes to the agency’s spacewalk schedule and moving forward with efforts to upgrade the space station’s power system.


NASA astronauts Christina Koch and Jessica Meir will venture outside the space station at 7:50 a.m. Thursday, Oct. 17 or Friday, Oct. 18. Live coverage will begin at 6:30 a.m. on NASA Television and the agency’s website.



Image above: NASA astronauts Christina Koch and Jessica Meir. Image Credit: NASA.


Space station managers have postponed three spacewalks previously scheduled for this and next week to install new batteries in order to first replace a faulty battery charge/discharge unit (BCDU). The BCDU failed to activate following the Oct. 11 installation of new lithium-ion batteries on the space station’s truss. The three spacewalks previously planned to continue the installation of additional lithium-ion batteries will be rescheduled.


The BCDU failure has not impacted station operations, safety of the crew, or the ongoing experiments aboard the orbiting laboratory, many in preparation for future human missions to the Moon and Mars. The station’s overall power supply, which is fed by four sets of batteries and solar arrays, remains sufficient for all operations. However, the faulty power unit does prevent a set of batteries installed earlier this month from providing increased station power.


The BCDU’s regulate the amount of charge put into the batteries that collect energy from the station’s solar arrays to power station systems during periods when the station orbits during nighttime passes around Earth. Two other charge/discharge units on the affected 2B power channel did activate as planned and are providing power to station systems.


This will be Koch’s fourth spacewalk and Meir’s first. Watch video of the two discussing the possibility of conducting a spacewalk together at: https://youtu.be/2o4XMOj2zzY?t=1113


Learn more about International Space Station research, operations, and its crew at:


https://www.nasa.gov/station


Expedition 61: https://www.nasa.gov/mission_pages/station/expeditions/future.html


International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html


Moon and Mars: https://www.nasa.gov/specials/moon2mars/


Image (mentioned), Text, Credits: NASA/Karen Northon/Stephanie Schierholz/JSC/Brandi Dean.


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Hubble Observes New Interstellar Visitor


ESA — Hubble Space Telescope logo.


17 October 2019



Comet 2I/Borisov

On 12 October 2019, the NASA/ESA Hubble Space Telescope provided astronomers with their best look yet at an interstellar visitor — Comet 2I/Borisov — which is believed to have arrived here from another planetary system elsewhere in our galaxy.


This observation is the sharpest  view ever of the interstellar comet. Hubble reveals a central concentration of dust around the solid icy nucleus.


Comet 2I/Borisov is only the second such interstellar object known to have passed through our Solar System. In 2017, the first identified interstellar visitor, an object dubbed ‘Oumuamua, swung within 38 million kilometres of the Sun before racing out of the Solar System.


“Whereas ‘Oumuamua looked like a bare rock, Borisov is really active, more like a normal comet. It’s a puzzle why these two are so different,” explained David Jewitt of UCLA, leader of the Hubble team who observed the comet.



Orbital Path of Comet 2I/Borisov

As the second interstellar object found to enter our Solar System, the comet provides various invaluable insights. For example, it offers clues to the chemical composition, structure, and dust characteristics of a planetary building block presumably forged in an alien star system a long time ago and far away.


“Because another star system could be quite different from our own, the comet could have experienced  significant changes during its long interstellar journey. Yet its properties are very similar to those of the Solar System’s building blocks, and this is very remarkable,” said Amaya Moro-Martin of the Space Telescope Science Institute in Baltimore, Maryland.



Hubble Space Telescope (HST)

Hubble photographed the comet at a distance of approximately 420 million kilometres from Earth [1]. The comet is travelling toward the Sun and will make its closest approach to the Sun on 7 December, when it will be twice as far from the Sun as Earth. It is also following a hyperbolic path around the Sun, and is currently blazing along at the extraordinary velocity of over 150 000 kilometres per hour. By the middle of 2020, the comet will be on its way back into interstellar space where it will drift for millions of years before maybe one day approaching another star system.


Crimean amateur astronomer Gennady Borisov first discovered the comet on 30 August 2019. After a week of observations by amateur and professional astronomers all over the world, the International Astronomical Union’s Minor Planet Center computed an orbit for the comet which showed that it came from interstellar space. Until now, all catalogued comets have come either from a ring of icy debris at the periphery of our Solar System, called the Kuiper belt, or from the Oort cloud, a shell of icy objects which is thought to be in the outermost regions of our Solar System, with its innermost edge at about 2000 times the distance between the Earth and the Sun.



Animation of Comet 2I/Borisov

2I/Borisov and ‘Oumuamua are only the beginning of the discoveries of interstellar objects paying a brief visit to our Solar System. There may be thousands of such interstellar objects here at any given time; most, however, are too faint to be detected with present-day telescopes.


Observations by Hubble and other telescopes have shown that rings and shells of icy debris encircle young stars where planet formation is underway. A gravitational interaction between these comet-like objects and other massive bodies could hurtle them deep into space where they go adrift among the stars.


Future Hubble observations of 2I/Borisov are planned through January 2020, with more being proposed.


Notes:


[1] This observation was made as part of DD Program #16009.
More information


The Hubble Space Telescope is a project of international cooperation between ESA and NASA.


Links:


Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/


Hubblesite release: https://hubblesite.org/contents/news-releases/2019/news-2019-53


Images, Animation, Video, Text, Credits: NASA/ESA, Bethany Downer, D. Jewitt, Stuart Wolpert (UCLA)/ J. Olmsted, F. Summers (STScI).


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NASA Selects Space Biology Experiments to Study Living Organisms on Russian Bion-M2...


ROSCOSMOS — Bion-M1 Mission patch.


Oct. 17, 2019


NASA has selected nine grant proposals for space biology research experiments, the results of which will contribute to the understanding of health risks humans will experience in deep space, including exploration at the Moon through the Artemis program and future missions to Mars. Selected investigators will have an opportunity to conduct rodent experiments to be flown on a biosatellite mission, known as Bion-M2, with the Russian space agency Roscosmos.


In 2022, Roscosmos and the Institute of Biomedical Problems of the Russian Academy of Sciences (IBMP RAS) plan to launch the second biosatellite in the Bion-M series. The goal of the uncrewed Cosmos/Bion missions, the first of which was launched in 1973, is to investigate how the space environment affects living organisms, with emphasis on animal morphology and physiology, gravitational biology, and radiation biology. American investigators have taken part in a great number of experiments flown on nine Cosmos/Bion missions of different durations between 1975 and 1996, the Foton-M1 and Foton-M2 missions completed in 2005 and 2007, as well as a 30-day Bion-M1 mission successfully implemented in 2013.



Radiations belt

In 2017, NASA Space Biology released a Research Announcement  (NNH16ZTT001N-BION/NNH18ZTT002N) entitled, “Solicitation of Proposals for Possible Inclusion in a Russian Bion-M2 Mission” that sought research proposals for Space Biology investigations using laboratory mice, cell cultures, invertebrate animals, and microorganisms.


Bion-M2 will carry 75 mice and launch to an altitude of 500-620 miles (800-1000 km) within the inner Van Allen Belt where they will be exposed to radiation levels much greater than those on the International Space Stations which operates at an altitude of about 250 miles (350 km) above Earth.


Selected proposals are compatible with the Bion-M2 research program and will help obtain new science results from the experiments performed at the above orbital altitudes. NASA expects that the selected investigations will advance our understanding of spaceflight-induced changes in biological systems and will therefore help inform human exploration missions at the Moon or beyond.


NASA’s participation in the Bion-M2 mission will be another stage in NASA/IBMP research collaboration, which has successfully continued for over 30 years and profoundly expanded our knowledge of spaceflight effects on living systems.  When fully implemented, a total of ~$3.2 million will be awarded for US investigations on Bion-M2.


Awards for Bion-M2 Studies:


Elizabeth Blaber, Ph.D., NASA Ames Research Center
Single cell analysis of bone marrow progenitor and differentiated progeny populations in response to long-duration spaceflight


Mary Bouxsein, Ph.D., Beth Israel Deaconess Medical Center, Harvard Medical School
The Effects of Spaceflight and Reloading on Skeletal Muscle and Bone


Michael Delp, Ph.D., Florida State University
High Altitude Spaceflight on the Bion-M2: Effects on Arterial and Venous Vessels


Lesya Holets, Ph.D., University of Kansas Medical Center Research Institute, Inc.
The impact of the prolonged LEO on male reproductive health and fertility in mice on the Bion-M2 mission.


Peter Lee, Ph.D., Ohio State University
Biomarkers Associated with Spaceflight-induced Cardiac Dysfunction


Xiao Wen Mao, Ph.D., Loma Linda University
Bion-M2 Spaceflight-induced Effects on Neurovascular Remodeling and Blood-retina Barrier Function: Role of Oxidative Stress


Kanokporn Rithidech, Ph.D., State University New York, Stony Brook
Proteomic analysis of mouse plasma after space flight with the Bion-M2 Mission


Candice Tahimic, Ph.D., KBR/Wyle, NASA Ames Research Center
Re-adaptation after spaceflight: mechanisms and impact on long-term tissue health


Russell Turner, Ph.D., Oregon State University
Time Course for re-adaption of thermoregulation and bone following spaceflight


The Space Biology Program is managed by the Space Life and Physical Sciences Research and Applications Division in NASA’s Human Exploration and Operations Mission Directorate at the Agency’s Headquarters in Washington, DC.


Related links:


Inner Van Allen Belt: https://www.nasa.gov/van-allen-probes


Artemis: https://www.nasa.gov/artemis


Human Research Program: http://www.nasa.gov/hrp


Moon to Mars: https://www.nasa.gov/topics/moon-to-mars/


Images, Text, Credits: NASA/Carlyle Webb/ROSCOSMOS.


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New research suggests global ice age changed the face of the planet

Curtin University researchers have discovered that a global ice age more than 600 million years ago dramatically altered the face of the planet, leaving a barren, flooded landscape and clear oceans.











New research suggests global ice age changed the face of the planet
Credit: NASA

The research, published in Terra Nova, examined how distinctive carbonate sedimentary rocks formed over the course of millions of years after the Snowball Earth.


The sedimentary rocks, much like the limestone in tropical oceans today, formed in oceans starved of sand and mud eroded from the land.


Lead author Ph.D. candidate Adam Nordsvan, from the School of Earth and Planetary Sciences at Curtin University, said the new research called into question previous suggestions that the formation of the characteristic rocks took place over a much shorter period of time.


«It was previously thought that these distinctive carbonate rocks were deposited over less than 10 thousand years, as the sea level rose when the ice that covered the entire globe melted, but we have shown that they were likely deposited over hundreds of thousands to millions of years following the sea-level rise,» Mr Nordsvan said.


«There is already some evidence that suggested these rocks took a long time to form, but no one had been able to explain why this might have occurred. What is intriguing about the period following Snowball Earth is that the planet surface was essentially completely renovated. It appears that the extended glacial period removed all the beaches, deserts, rivers and floodplains, and reset important Earth systems that took millions of years to recover.»


Co-author Dr. Milo Barham, also from Curtin’s School of Earth and Planetary Sciences, said the findings may have important implications for the evolution of complex life.


«The melting of ice sheets after Snowball Earth caused a dramatic rise in sea level, ultimately flooding the continents, driving a remarkable retreat of shorelines and the development of clearer ocean water,» Dr. Barham said.


«Researchers have long been aware that the timing of Snowball Earth and the development of more complex life seem to have coincided, but no one has really thought about how the oceans being starved of sediment might have helped ancient organisms thrive in the oceans.»


Author: Lucien Wilkinson | Source: Curtin University [October 15, 2019]



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The brain does not follow the head

The human brain is about three times the size of the brains of great apes. This has to do, among other things, with the evolution of novel brain structures that enabled complex behaviors such as language and tool production. A study by anthropologists at the University of Zurich now shows that changes in the brain occurred independent of evolutionary rearrangements of the braincase.











The brain does not follow the head
CT/MRI datasets of a human (left), chimpanzee (center), and gorilla (right). Surface reconstructions of bony structures
were derived from CT data, while volume renderings of brain segmentations were obtained from
postprocessed MRI data [Credit: J.L. Alatorre Warren, UZH]

The human brain is like a fish in an aquarium, floating inside the liquid-filled braincase — but filling it out almost completely. The relationship between the brain and the braincase, and how they interacted during human evolution, has been occupying the minds of researchers for almost a century. They addressed this question by studying brain-braincase relationships in our own species, and in our closest living relatives, the great apes.


Quantifying spatial relationships between brain and cranial structures


Jose Luis Alatorre Warren, researcher at the Department of Anthropology of the University of Zurich, tackled this question using computed tomography (CT) and magnetic resonance imaging (MRI) data from humans and chimpanzees.


By combining CT/MRI data, he was able to quantify the spatial relationships between brain structures such as gyri (convolutions) and sulci (furrows) on the one hand, and cranial structures such as bony sutures on the other.


The results show that the characteristic spatial relationships between brain and bone structures in humans are clearly distinct to those in chimpanzees. While the brain and its case continued to evolve side by side, they did so along largely independent evolutionary paths.


Bipedalism leads to changes in braincase


For example, brain structures related to complex cognitive tasks such as language, social cognition and manual dexterity expanded significantly in the course of human evolution. This becomes visible as a shift of the neuroanatomical boundaries of the frontal lobe of the brain.


Transformation of braincase (black) and brain (red-to-blue) structures from chimpanzee to human, 


and back to chimpanzee [Credit: J.L. Alatorre Warren]


This shift, however, did not affect the bony structures of the braincase. Instead, changes in the braincase largely reflect adaptations to walking upright on two legs, or bipedalism. For example, the opening at the skull base for the spinal cord moved forward during human evolution in order to optimize balance of the head atop the vertebral column. However, these evolutionary changes to the braincase did not have an effect on our cerebral structures.


Point of reference for future research


«The brain followed its own evolutionary path of neural innovation while freely floating in the braincase,» summarizes Alatorre Warren. «The position and size of braincase bones thus don’t enable us to draw conclusions about evolutionary changes in the size or rearrangement of adjacent brain regions.» Co-authors Marcia Ponce de Leon and Christoph Zollikofer believe their study’s data provide an important point of reference for future research: «Having answered the brain-braincase question for humans and great apes, we can now take a fresh look at the braincases of fossil hominids.»


The study is published in Proceedings of the National Academy of Sciences.


Source: University of Zurich [October 15, 2019]



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Study ‘cures’ oldest case of deafness in human evolution

An international team of researchers including faculty at Binghamton University, State University of New York, has published a new study examining a 430,000-year-old cranium of a human ancestor that was previously described as deaf, representing the oldest case of deafness in human prehistory.











Study 'cures' oldest case of deafness in human evolution
Cranium 4 from the site of the Sima de los Huesos in northern Spain
[Credit: Binghamton University]

«The current finding is significant because we have definitively shown this individual was not deaf. Rather than rely on subjective assessments based on the presence of a pathological condition in the ear canals, we have studied in detail the physiological implications of the pathology and have found it does not affect hearing,» said Binghamton University anthropologist Rolf Quam. «This is a classic pathology that has been identified in more recent archaeological skeletons and has long been a source of speculation regarding its effects on the lifeways of past human populations. This is the first time the effects have been studied so precisely.»


The study, led by anthropologists and clinicians at the University of Alcala and HM Hospitals in Spain, focuses on Cranium 4 from the site of the Sima de los Huesos in northern Spain. This is one of the most complete crania known from the Middle Pleistocene time period and is considered to be an early ancestor of the Neandertals.


The right and left ear canals in this individual both show the presence of extra bony growths (exostoses, in technical terms) which partially block the ear canal. Similar pathologies have been documented in Neandertals across Europe and the Middle East and have been frequently reported in archaeological skeletons from more recent time periods. Although the precise reason behind the formation of this pathology in living humans is unclear, it has often been associated with repeated exposure to cold water.


The researchers analyzed high resolution computed tomography (CT) scans to create virtual 3D models of the ear structures. Data from measurements taken on the 3D models were then entered into a software program that predicts hearing abilities based on the anatomical measurements of the ear. This model was applied previously to other healthy individuals from the same site, who were shown to have hearing abilities that closely matched those in modern humans.



Relying on this methodology, the researchers hoped to document more precisely the degree of hearing loss exhibited by Cranium 4 individual. Surprisingly, despite this pathology in the ear canals, this individual did not suffer any appreciable differences in hearing compared to the healthy individuals from this same site.


«We were very surprised by the results,» said coauthor Manuel Rosa of the Universidad de Alcala «and expected for this individual to have suffered some degree of hearing loss.» This represents one of the classic pathological conditions of the human skeleton known to anthropologists for decades, and the academic literature is rife with explanations for why these bony growths appear and what their effects are on the individuals showing them.


«Our study is the first detailed attempt to analyze the clinical implications of this pathology in our fossil human ancestors,» said lead researcher Mercedes Conde, «and our results suggest caution in attributing auditory consequences to the presence of these bony growths.»


In living humans, hearing loss has clear social consequences since it is associated with delays in language acquisition, increased behavioral problems and psychological stress. Inferring such ephemeral aspects of human social life in ancient fossils is challenging and only rarely possible. The results of this new study suggest that, rather than representing a marginalized individual, the Cranium 4 individual appears to have been fully capable of engaging in the social life and activities of their group.


«This study represents a novel approach to examining a well-known pathological condition, relying on medical imaging technology and virtual 3D models to assess the clinical implications of an ancient disease and to reveal new insights into the lifeways of our ancestors,» said Quam.


The researchers have some ear bones (malleus and incus) from Cranium 4’s middle ear cavity that they plan to study in the near future.


The findings are published in the Journal of Human Evolution.


Source: Binghamton University [October 15, 2019]



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