четверг, 20 сентября 2018 г.

Scientists hopeful of finding Capt Cook’s ship the Endeavour

Maritime historians have urged caution over the discovery of a wreck marine archaeologists believe may be the ship Captain Cook took to Australia and the South Pacific almost 250 years ago.











Scientists hopeful of finding Capt Cook's ship the Endeavour
A replica of the Endeavour, as researchers close in on finding the wreckage of the real thing [Credit: AAP]

Australian and US experts say they could have found the HMB Endeavour’s wreck just off a small island called Goat Island in Newport Harbour on America’s east coast.


The wreck’s dimensions are close to those of the famous ship Captain James Cook sailed into Botany Bay in 1770.


But Australian National Maritime Museum director Kevin Sumption says although the team has narrowed the possible site for the wreck of the Endeavour from 12 down to one site, it’s very early days.


“There is still a lot more detailed work, analysis and research that has to happen before we can definitively say we have found the remains of James Cook’s HMB Endeavour,” he said in a statement on Wednesday.


The discovery comes 25 years after the search for the former British Royal Navy vessel began.


Wood samples will be carefully collected from the wreck and taken back to a Sydney laboratory for testing.


“If the analysis shows that it’s American timber then it’s likely not Endeavour, if it shows that its UK timbers then that helps make it closer to being the Endeavour,” ANMM spokeswoman Shirani Aththas said.


Rhode Island Marine Archaeology Project founder Dr Kathy Abbass came across historical documents in London that guided her team to the general area in Newport Harbour.


They believe the Endeavour, which was renamed Lord Sandwich, was deliberately sunk by the British in 1778 during the American War of Independence and that silt may have helped preserve it.


RIMAP and the ANMM will hold a press conference on Friday at Rhode Island where imagery collected during the fieldwork will be released.


It is likely the Endeavour will remain in Rhode Island if it is found.


Source: AAP [September 19, 2018]



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Bronze Age helmets found in Eastern Slovakia

The Eastern Slovakia Museum in Košice has presented two unique bronze helmets from the late Bronze Age. A mushroom picker found them last year near the village of Trhovište in Michalovce county. The finder brought the objects to the museum in January of this year. The museum’s archaeologist Dárius Gašaj informed the Regional Monument’s Board.











Bronze Age helmets found in Eastern Slovakia
Bronze Age helmets, cheek protectors, arm guards, ca. 3200 years old
[Credit: František Iván, TASR]

“This precious finding consists of two Bronze helmets, partly stuck to each other. There were also two pairs of protective cheek pads and two spiral arm guards,” said Róbert Pollák, director of the museum, as quoted by the SITA newswire.
The finder wishes to remain anonymous. The archaeologist with a colleague from the Regional Monument’s Board examined the site of the find in detail.











Bronze Age helmets found in Eastern Slovakia
Eastern Slovakia Museum archaeologist Dárius Gašaj with one of the helmets
[Credit: František Iván, TASR]

The discovery, worth approximately €60,000, is the property of the state now. As Pollák said, the museum, together with the Košice Self-governing Region requested it be added to the collection of the museum.
Discoveries of helmets from the Bronze Age are rare not only in Slovakia but in the whole of Europe, according to Gašaj. The helmets from Trhovište are western European style made from two shaped bronze plates. The decorated sides are connected with a central three-toothed comb that has a hole for attaching a decorative plume. Other holes at the sides and at the bottom edge are to attach the protective cheek pads.











Bronze Age helmets found in Eastern Slovakia
Protective cheek pads [Credit: František Iván, TASR]

Only three similar pieces had been found, all of them in the Eastern Alpine area.
The origin of the helmets from Trhovište remains unclear. They were probably traded objects imported for the highest society elite – military chiefs. The helmets were used and repaired. They were more a symbol of the status of the bearer, a symbol of his position and power than protective equipment.











Bronze Age helmets found in Eastern Slovakia
Spiral arm guards [Credit: František Iván, TASR]

The display also includes the back part of some plate armour plate that was found long ago in Čierna nad Tisou and also some fragments discovered in Šarišské Michaľany.


Similar helmets have been found in Lúčky, Spišská Belá and Žaškov but they were made only from one sheet of bronze. They originated between the 12th and 10th century BC.


Source: The Slovak Spectator [September 19, 2018]



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Remains of weapons, sandals and coins shed new light on Roman conquest of Northwest...

Newly discovered remains of weapons, hobnails from sandals and coins will help experts piece together the untold story of how the Romans won control of Galicia and Northern Portugal from local tribes for the first time.











Remains of weapons, sandals and coins shed new light on Roman conquest of Northwest Iberia
Aerial view of Penedo dos Lobos Roman camp [Credit: Dr João Fonte/Roman Army.eu]

Archaeologists have found the oldest evidence yet of the presence of legions in Galicia in the Penedo dos Lobos Roman camp (Manzaneda, Ourense, Galicia). This significant discovery will help to redefine the history of the period.


Until now historians had found few clues about the actions of Roman soldiers in these regions. The findings show some, smaller groups, of legionnaires were probably sent on scouting missions in the area to investigate the landscape, rather than to fight, suggesting the region was already under Roman control by the end of 1st century BC, when the bronze coins found were made.


The bronze coins, dating from 25-22 BC, thought to be payment for the legionnaires, were minted by Publius Carisius, who was Augustus’ legate during the Cantabrian-Asturian Wars.


Dr. João Fonte, from the University of Exeter,director of the archaeological survey, said: “People have suggested Roman troops were in this area, but until now it was only speculation. This findings, which date from the time of the Cantabrian-Asturian Wars, really will allow us to rewrite the history books.”


Northwest Iberia was effectively annexed by Rome in 1st century BC, but it has been hard for experts to reconstruct events because of a lack of archaeological evidence, in particular in regions as Galicia and Northern Portugal. This historical context is better known in the Asturian and Cantabrian areas, where the last war episodes took place in Augustan times.


The findings were all discovered in the remains of the Penedo dos Lobos Roman camp, the first of its kind to be investigated in Galicia. The research team are using remote sensing technology to find former Roman military camps in Galicia and Northern Portugal. They have found around 20 in the past two years in these regions and are now doing further work to investigate remains they might still hold. Remote sensing technology has allowed the experts to see clearly the remains of the four gates which define the Roman military enclosure. Almost the entire perimeter of the defensive rampart is still in place. All were built in stone and are exceptionally well preserved.


Dr. Fonte said: “The evidence we have so far suggests this was a small contingent of soldiers, of about 800 to 1,000 men. We also know it wasn’t a temporary camp, as the site is fully built in stone, so they could have been in the area for several weeks or even months. They could have been tasked with specific missions, such as mapping the landscape or looking at the potential resources such as mining. This shows the Romans ran different types of military operations in this part of Iberia.


“Marching legions tend to leave much less evidence of occupation as they were only passing through, as in the Roman camps documented in Asturias and Cantabria, where we have been able to track the movements of the soldiers in these regions.”


Source: University of Exeter [September 19, 2018]



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Research proves South East Asian population boom 4,000 years ago

Researchers at The Australian National University (ANU) have uncovered a previously unconfirmed population boom across South East Asia that occurred 4,000 years ago, thanks to a new method for measuring prehistoric population growth.











Research proves South East Asian population boom 4,000 years ago
The Man Bac burial site in Vietnam [Credit: Lorna Tilley]

Using the new population measurement method, which utilises human skeletal remains, they have been able to prove a significant rapid increase in growth across populations in Thailand, China and Vietnam during the Neolithic Period, and a second subsequent rise in the Iron Age.


Lead researcher Clare McFadden, a PhD Scholar with the ANU School of Archaeology and Anthropology, said the population trend was consistent across samples taken from 15 locations.


“We saw huge population growth associated with the agricultural transition,” McFadden said. “Up until about 4,000 years ago you have hunter gatherer type populations, then you have the introduction and intensification of agriculture. Agricultural transition has been widely studied around the world and we consistently see significant population growth as a result.”


The reason these population changes have never been quantified before is the tools used to measure prehistoric populations were all designed for Europe and the Americas where archaeological conditions are different to Asia.











Research proves South East Asian population boom 4,000 years ago
Lead researcher Clare McFadden, a PhD Scholar with the ANU School of Archaeology and Anthropology
[Credit: Australian National University]

Ms McFadden said the difference comes down to how children are represented in population numbers.


“For skeletal remains in Europe and America we often see the complete absence of infants and children, they are very poorly represented,” she said. “The preservation isn’t good – small bones don’t preserve well. Children are also thought to often be buried in a different cemetery to adults. So the method researchers used to measure populations excluded children because they didn’t have accurate representation.”


Ms McFadden said her new method for determining the rate of natural population increase takes into account the proportion of infants and children compared to the total population. This way researchers were able to bring population growth figures in line with other archaeological evidence in the region which suggested a rapid rise.


“In South East Asia and the Pacific, we actually have pretty good preservation of bones from children,” she said. “The skeletal evidence was there, we were seeing populations with huge numbers of infants and children compared to the adult populations, which suggests it was a growing population at that time. But the existing tools weren’t detecting that growth. The trends the new tool found aligned perfectly with what researchers expect to see in response to agriculture.”


The study has been published in a paper in the Journal of Archaeological Science.


Author: Aaron Walker | Source: Australian National University [September 19, 2018]



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Research finds Aboriginals lived in Western Desert 50,000 years ago

Archaeologists from The University of Western Australia working with Traditional Custodians from the Birriliburru Indigenous Protected Area (IPA) have recovered evidence that people lived in the Australian arid zone 50,000 years ago.











Research finds Aboriginals lived in Western Desert 50,000 years ago
Pleistocene backed artefact [Credit: J. McDonald et at. PLOS ONE, 2018]

This is 10,000 years earlier than previously understood for the interior deserts of Australia, and among some of the earliest known evidence for people living in deserts anywhere in the world.


The remote Carnarvon Ranges are near the Canning Stock Route. Evidence from the Karnatukul site (previously known as Serpents Glen) indicates that people lived in this interior desert from very early in the settlement of Australia and that they remained in these ranges during the last Ice Age.


Lead Investigator Professor Jo McDonald, Director of UWA’s Centre for Rock Art Research and Management, said a significant find supported that this early group of desert peoples were technological innovators.


“We found in deposits dating back around 43,000 years ago an early backed microlith, a hafted multifunctional tool which could be used as either a spear barb or for wood-working,” Professor McDonald said.


“This is more than 15,000 years earlier than other known Australian examples of this tool type. Residue found on the tool indicates that hafting technology was practised much earlier than had been previously demonstrated in Australia. Tools such as this are found across most of southern and eastern Australia, but most are dated to the last 4,000 years.”


Professor McDonald said the findings supported the notion that the first Australians adapted with ingenuity and flexibility as they dispersed into every bioregion of Australia within ten millennia after arriving on this continent.


“The fact that we have also been able to demonstrate a range of symbolic behaviours in the last 1,000 years – with rock art production and extraordinarily high levels of site use at this same time – demonstrates the continuity and complexity of long-term connections by Australian desert peoples,” she said.


Co-Investigator Professor Peter Veth, UWA Kimberley Foundation Ian Potter Chair in Rock Art Archaeology, said the finding represented a revolution in understanding the adaptive and technological sophistication of early Aboriginal peoples living in the interior deserts of Australia.


“It’s enthralling to see scientific and Aboriginal narratives working together to create an extraordinary new canvas for the vast desert landscapes of the Australian imagination,” Professor Veth said.


Professor McDonald said the Birriliburru IPA is an area of exclusive possession native title determination area held in trust by Mungarlu Ngurrarankatja Rirraunkaja Aboriginal Corporation. The Carnarvon Ranges remain closed to unaccompanied tourist visitation.


The Birriliburru Rangers actively patrol and conduct land management activities in the area to protect the cultural and conservation values.


The findings are published in PLOS ONE.


Source: University of Western Australia [September 20, 2018]



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Discovery of an Early Iron Age tumulus on Anavlochos, Crete

As part of a 5-year (2017-2021) programme of systematic excavations on Anavlochos, Crete, an Early Iron Age tumulus was discovered in August 2018 by a team from the French School at Athens, under the direction of Florence Gaignerot-Driessen.











Discovery of an Early Iron Age tumulus on Anavlochos, Crete
Aerial photograph of the tumulus [Credit: ©EFA/Anavlochos Project/L. Kocher-A. Chalais]

Inside a circle of limestone rubble, 15 m in diameter, three circular pits contained the remains of burials and cremation pyres. In the eastern part of the circle, a fourth pit, from which no human remains were recovered, yielded an assemblage of 15 vessels and five spearheads in a very good state of preservation.











Discovery of an Early Iron Age tumulus on Anavlochos, Crete
Assemblage from the fourth pit [Credit: ©EFA/Anavlochos Project/O. Vidalis]










Discovery of an Early Iron Age tumulus on Anavlochos, Crete
Spearhead from the fourth pit [Credit: ©EFA/Anavlochos Project/P. Baulain]

Under a sandstone block that marked the centre of the circular tumulus on the stone surface, was a rectangular pit, half built, half cut in the bedrock. The location of this pit, the thick layer of charcoal in it, as well as the calcined side walls, human remains and artifacts recovered from it, all indicate that it is the location of the primary cremation of the first burial associated with the tumulus. A small cist grave has also been excavated on the south-east edge of the circular tumulus containing the pit graves, adjoining its enclosure wall.



3D reconstruction of the fourth pit [Credit: ©EFA/Anavlochos Project/C. Judson, L. Kocher, A. Chalais]


A preliminary study of the pottery recovered shows that this imposing funerary monument was in use during the 8th and the 7th c. BCE. This tumulus is situated in the lower part of a slope where three other tumuli, unfortunately very ruined by erosion and repeated looting in the past, have also been located. The excavation of the tumulus and the archaeological survey of this area have been completed.











Discovery of an Early Iron Age tumulus on Anavlochos, Crete
Flying over the slope with the four tumuli [Credit: ©EFA/Anavlochos Project/L. Kocher-A.Chalais]

The 2018 excavations benefited from the support of the EFA, INSTAP, ARC programme Crisis (UCLouvain), ARPAMED, FNRS, Cyprus Institute and the universities of Lorraine, Stanford, North Carolina, Cardiff and Heidelberg.


Source: French School at Athens [September 20, 2018]



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Recent tectonics on Mars


ESA – Mars Express Mission patch.


20 September 2018


These prominent trenches were formed by faults that pulled the planet’s surface apart less than 10 million years ago.


The images were taken by ESA’s Mars Express on 27 January, and capture part of the Cerberus Fossae system in the Elysium Planitia region near the martian equator.



Mars Express view of Cerberus Fossae

The fossae – meaning ‘ditches’ or ‘trenches’ in Latin – stretch for more than 1000 kilometres from the northwest to the southeast.


They cut through impact craters and hills along the way, as well as 10 million year old volcanic plains, indicating the relative youth of their formation.



Cerberus Fossae in context

They vary in width, typically from a few tens of metres to over a kilometre wide, and are thought to be tectonic features originating from faults that stretch the upper layers of the surface apart.


They could be linked to injections of lava at depth deforming the surface above, perhaps originating from the trio of volcanoes that are located to the northwest.


Rounded collapse pits observed in the northern part (north is to the right in the main colour image) indicate an early stage of surface sinking; in other places rounded features can be seen connecting up to create longer cracks.



Perspective view of Cerberus Fossae

Scientists studying this region have speculated that the fractures could rupture the crust to a certain depth, allowing lava or groundwater to escape to the surface.


To the west, as seen in the context image, the Athabasca Valles outflow channel links with the fossae system.



Perspective view of Cerberus Fossae

The dark material seen in the largest crater at the north (right) and around some of the cracks is sand blown by the wind across the martian surface.


Mars Express celebrates 15 years in orbit this year, and scientists are discussing some of the mission’s highlights at the European Planetary Science Congress this week in Berlin, Germany.



 Topographic view of Cerberus Fossae

During its mission lifetime it has taken over 40,000 images of Mars and its two moons with the high resolution stereo camera, as well as context images with its Visual Monitoring Camera. It has also collected a vast dataset with its suite of scientific instruments that are analysing the planet from its ionosphere, atmosphere, and interaction with the solar wind, through to its subsurface with radar.



Cerberus Fossae in 3D

Explore all available Mars Express data in ESA’s Planetary Science Archive: https://www.cosmos.esa.int/web/psa/mars-express


Related links:


European Planetary Science Congress: https://meetingorganizer.copernicus.org/EPSC2018/oral_programme/29912


Visual Monitoring Camera: https://www.flickr.com/photos/esa_marswebcam/


Mars Express: http://www.esa.int/Our_Activities/Space_Science/Mars_Express


Images, Text, Credits: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO/NASA MGS MOLA Science Team.


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Scientists ID Three Causes of Earth’s Spin Axis Drift


JPL – Jet Propulsion Laboratory logo.


September 20, 2018


A typical desk globe is designed to be a geometric sphere and to rotate smoothly when you spin it. Our actual planet is far less perfect — in both shape and in rotation.


Earth is not a perfect sphere. When it rotates on its spin axis — an imaginary line that passes through the North and South Poles — it drifts and wobbles. These spin-axis movements are scientifically referred to as “polar motion.” Measurements for the 20th century show that the spin axis drifted about 4 inches (10 centimeters) per year. Over the course of a century, that becomes more than 11 yards (10 meters).



Image above: The observed direction of polar motion, shown as a light blue line, compared with the sum (pink line) of the influence of Greenland ice loss (blue), postglacial rebound (yellow) and deep mantle convection (red). The contribution of mantle convection is highly uncertain. Image Credits: NASA/ JPL-Caltech.


Using observational and model-based data spanning the entire 20th century, NASA scientists have for the first time identified three broadly-categorized processes responsible for this drift — contemporary mass loss primarily in Greenland, glacial rebound, and mantle convection.


“The traditional explanation is that one process, glacial rebound, is responsible for this motion of Earth’s spin axis. But recently, many researchers have speculated that other processes could have potentially large effects on it as well,” said first author Surendra Adhikari of NASA’s Jet Propulsion Laboratory in Pasadena, California. “We assembled models for a suite of processes that are thought to be important for driving the motion of the spin axis. We identified not one but three sets of processes that are crucial — and melting of the global cryosphere (especially Greenland) over the course of the 20th century is one of them.”


In general, the redistribution of mass on and within Earth — like changes to land, ice sheets, oceans and mantle flow — affects the planet’s rotation. As temperatures increased throughout the 20th century, Greenland’s ice mass decreased. In fact, a total of about 7,500 gigatons — the weight of more than 20 million Empire State Buildings — of Greenland’s ice melted into the ocean during this time period. This makes Greenland one of the top contributors of mass being transferred to the oceans, causing sea level to rise and, consequently, a drift in Earth’s spin axis.


While ice melt is occurring in other places (like Antarctica), Greenland’s location makes it a more significant contributor to polar motion.


“There is a geometrical effect that if you have a mass that is 45 degrees from the North Pole — which Greenland is — or from the South Pole (like Patagonian glaciers), it will have a bigger impact on shifting Earth’s spin axis than a mass that is right near the Pole,” said coauthor Eric Ivins, also of JPL.


Previous studies identified glacial rebound as the key contributor to long-term polar motion. And what is glacial rebound? During the last ice age, heavy glaciers depressed Earth’s surface much like a mattress depresses when you sit on it. As that ice melts, or is removed, the land slowly rises back to its original position. In the new study, which relied heavily on a statistical analysis of such rebound, scientists figured out that glacial rebound is likely to be responsible for only about a third of the polar drift in the 20th century.


The authors argue that mantle convection makes up the final third. Mantle convection is responsible for the movement of tectonic plates on Earth’s surface. It is basically the circulation of material in the mantle caused by heat from Earth’s core. Ivins describes it as similar to a pot of soup placed on the stove. As the pot, or mantle, heats, the pieces of the soup begin to rise and fall, essentially forming a vertical circulation pattern — just like the rocks moving through Earth’s mantle.


With these three broad contributors identified, scientists can distinguish mass changes and polar motion caused by long-term Earth processes over which we have little control from those caused by climate change. They now know that if Greenland’s ice loss accelerates, polar motion likely will, too.


The paper in Earth and Planetary Science Letters is titled “What drives 20th century polar motion?” Besides JPL, coauthor institutions include the German Research Centre for Geosciences, Potsdam; the University of Oslo, Norway; Technical University of Denmark, Kongens Lyngby; the Geological Survey of Denmark and Greenland, Copenhagen, Denmark; and the University of Bremen, Germany. An interactive simulation of how multiple processes contribute to the wobbles in Earth’s spin axis is available at: https://vesl.jpl.nasa.gov/sea-level/polar-motion/


Image (mentioned), Text, Credits: NASA/JPL/Esprit Smith.


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Tropics are widening as predicted by climate models, research finds

Scientists have observed for years that the Earth’s tropics are widening in connection with complex changes in climate and weather patterns. But in recent years, it appeared the widening was outpacing what models predicted, suggesting other factors were at work.











Tropics are widening as predicted by climate models, research finds
Australia’s Lake Hume is on the fringes of the tropics and could be affected by the expansion
of desert areas associated with widening of the tropics [Credit: Tim J. Keegan]

A new paper co-authored by Indiana University Bloomington researcher Paul Staten, however, finds that the most up-to-date models and the best data match up reasonably well.


“If we compare the observed trends of how the tropics have widened to modeling trends, it’s actually not outside of what the models predict,” said Staten, assistant professor of atmospheric sciences in the College of Arts and Sciences.


Staten is an affiliated researcher with the IU Environmental Resilience Institute, which was established under Prepared for Environmental Change, the second initiative funded by the university’s Grand Challenges Program.


Staten said the research should add confidence to predictions based on current climate models.


“Climate change should continue to expand the tropics over the next several decades,” he said. “But the expansion may not continue at the rapid rate we’ve seen; at times it may even temporarily contract.”


The authors conclude that the tropics have been widening at an average rate of about 0.2 degrees latitude, or about 17 miles, per decade in both the Northern and Southern hemispheres. The rate varies widely from year to year and from location to location.


Widening of the tropics is important because it could be associated with severe changes in climate, Staten said. The world’s hot, dry deserts tend to be located in bands along the northern and southern edges of the tropics, so widening of the tropics could lead to expansion of the subtropical deserts. At sea, the edges of the tropics are zones of high salinity and low marine productivity.


About half of the world’s population lives in or near subtropical semi-arid climate zones, the researchers write, so changes in the subtropical climate could affect billions of people.


The researchers focus on five factors that may influence the widening of the tropics:


– Increases in greenhouse gas emissions, which lead to a warmer global climate.


– Depletion of ozone in the stratosphere over the South Pole, which probably shifts the edge of the tropics, especially in the Southern Hemisphere.


– Aerosols from volcanic eruptions.


– Pollution, including soot and ozone in the troposphere.


– Natural variation, including changes in sea surface temperatures tied to the El Niño and La Niña phenomena.


Given the complexity of the factors, the authors say, it is difficult for now to tease out differences in natural and human-caused influences on the widening of the tropics. But if greenhouse gas emissions and pollution continue to increase, they write, human causes will become more obvious.


The paper was published in the journal Nature Climate Change.


Source: Indiana University [September 17, 2018]



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Micronizing ocean plastics threaten sea turtle populations, ocean life cycle

Ingestion of degrading ocean plastics likely poses a substantial risk to the survival of post-hatchling sea turtles because the particles can lead to blockages and nutritional deficiencies, according to new research from Loggerhead Marinelife Center and the University of Georgia. This puts the survival of all sea turtle populations at risk, because sea turtles may take decades to become sexually mature. The study also suggests that micronizing plastics could have tremendous negative implications for the ocean’s food web.











Micronizing ocean plastics threaten sea turtle populations, ocean life cycle
This loggerhead post-hatchling was rehabilitated and released by the Loggerhead Marlinelife Center.
The vial contains plastic that was excreted by the sea turtle during its stay at LMC in 2017
[Credit: Loggerhead Marinelife Center]

“We may be in the early phases of the first micronized plastic waste-associated species population decline or extinction event,” said co-author Branson W. Ritchie, a veterinarian with more than 30 years of experience in exotic and wildlife medicine and the director of technology development and implementation for the UGA New Materials Institute. “But, an even bigger issue is what micronizing plastics are doing to the ocean’s ecosystem. As ocean plastics continue to micronize, smaller and smaller particles are being consumed by the smallest creatures in our oceans, which compromises the entire food chain, because the plastic in these animals inhibits their ability to uptake the nutrients they need to survive. If the level of mortality we have observed in post-hatchling sea turtles also occurs for zoo plankton, baby fish and crustaceans, then we will witness a complete disruption in our ocean life cycle.”


The researchers collected 96 post-hatchling sea turtles that had washed back onto the beaches along a stretch of Florida’s coastline between Vero Beach and Lake Worth. The area is just south of the Archie Carr National Wildlife Refuge, named for the researcher who spurred the sea turtle conservation movement, and is part of the largest rookery in the United States for loggerhead and green turtles. More than 90 percent of the U.S. loggerhead population nests in Florida, said study co-author Charles Manire, a veterinarian who is director of research and rehabilitation for Loggerhead Marinelife Center.


Nearly half of the 96 recovered turtles were rehabilitated by LMC and released back into the ocean. During their time in rehabilitation, all passed some amount of plastic, said licensed veterinary technician Samantha Clark, a co-author who cared for the turtles at LMC. The remainder of the collected turtles died and 27 of these were examined for the study. Ninety-three percent had some amount of ingested plastic particles in them, leading the team to theorize that many died due to blockages or nutritional deficiencies associated with plastic ingestion.


“Sea turtles are known to mistake ocean plastics for prey, like crab or fish eggs, or in the case of larger sea turtles, floating plastic bags for jellyfish,” Clark said.


“Our findings suggest that far fewer post-hatchlings may be surviving long enough to reproduce. This has devastating implications for the seven species of sea turtles struggling to survive,” said Manire. “If other sea turtle populations are experiencing similar mortality rates, we predict that there will be insufficient numbers of sea turtle hatchlings reaching sexual maturity to offset natural and other human-associated losses.”


Historically, researchers have estimated that only one in 1,000 survives long enough to fully mature, but some recent estimates have suggested that number may be one in 10,000.


As plastic waste has accumulated in the marine environment, there has been an increase in the reports describing ingestion of plastics by sea turtles. Plastic is now the most common form of marine debris. Globally, at least 690 marine species, including sea turtles, seabirds, seals, sea lions, whales, fish and invertebrates, have reportedly become ill or died following entanglement in or ingestion of marine plastics.


The study team made another remarkable discovery: Once ingested, the plastic particles may continue to deteriorate to a size so small that it has never been documented or described previously for ingested particles. Using Raman spectroscopy and atomic force microscopy, the team characterized both the types of plastics and the sizes of the particles they found.


“We found particles ranging from millimeter-sized fragments to nanoparticles that measured on average 52 nanometers, and the smallest fragments we found measured 5 nanometers,” said Jason Locklin, director of the UGA New Materials Institute and a co-author on the study. “The smaller these particles are, the more unstable they become.”


“Of these larger mesoparticles, 54.1 percent of what we found were polyethylene and 23.7 percent were polypropylene,” said lead author Evan White, an assistant research scientist at the New Materials Institute who analyzed the particles. “Polyethylene is the most common plastic and is primarily used for packaging, especially food packaging. Polypropylene is the second most-commonly produced plastic and has a wide variety of uses, including food packaging.”


For examples of scale, microparticles include pollen, flour or powdered sugar. A nanometer is one-billionth of a meter; a human hair is about 80,000 to 100,000 nanometers wide.


The study was funded in part by the RWDC Environmental Stewardship Foundation, which has partnered with the UGA New Materials Institute to research and develop bio-based, fully biodegradable plastics.


The study was published in Environmental Science and Technology.


Author: Kat Gilmore | Source: University of Georgia [September 17, 2018]



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Research helps understand group relationships in gorillas

A study by researchers from The University of Western Australia has found that the behaviour between groups of African mountain gorillas is very much influenced by the strong, life-long bonds they form with members of their group.











Research helps understand group relationships in gorillas
Credit: University of Western Australia

Published in Animal Behaviour, the research also found that conflict is far more likely to involve alpha male gorillas who are the leaders and protectors of their group. The researchers observed interactions between 10 groups of mountain gorillas in Rwanda over a one-year period and combined their observations with data collected by the Karisoke Research Center (Dian Fossey Gorilla Fund International) between 2003 and 2015.
They found male gorillas engaged in aggressive fights to protect the members in their group. However, the bonds formed between former group members living in different groups dramatically reduced hostility upon reunion, and sometimes promoted gorillas to exchange affiliative behaviours, such as playing and grooming.


Lead researcher Dr. Melanie Mirville, from UWA’s School of Anatomy, Physiology and Human Biology, said the bonds formed between gorillas were so strong that interactions between these particular groups were usually peaceful, even after years of separation.











Research helps understand group relationships in gorillas
Credit: University of Western Australia

“What’s interesting is people often have the perception that gorilla behaviour is very much influenced by competition for females or over a food source, but there’s also a good proportion of behaviour that is peaceful as a result of long-lasting social relationships,” Dr. Mirville said.
Dr. Mirville said the research showed similarities to social interaction in humans.


“As humans we are friendlier if we bump into someone we know in comparison to people we don’t know or trust,” she said. “We also have an ongoing history of conflict and war, alliances and peace-making.


“By understanding the intergroup behaviours of primates in response to their existing social history, we can better understand the complex origins of our own remarkable social behaviour, including hostility to people or groups we are not familiar with.”


Dr. Mirville said during her research she was never nervous about working with mountain gorillas.


“The gorillas studied have been observed by researchers from their day of birth so they didn’t see us as a threat,” she said. “You still want to keep a good distance from the group though; the alpha males can grow up to around 200kg and can be very protective.”


Author: David Stacey | Source: University of Western Australia [September 17, 2018]



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Scientists closing in on source of Shetland tsunamis

Shetland has been hit by at least two more tsunamis in the past 10,000 years than previously thought, and scientists are working to identify where the giant waves originated.











Scientists closing in on source of Shetland tsunamis
Dury Voe in Yell, Shetland, is one of the sites where researchers have found evidence
of a recent tsunami hitting the British Isles [Credit: PlanetEarth Online]

Around 8,200 years ago, the Storegga submarine landslide off the coast of Norway caused a 20m-high tsunami to sweep across Shetland. Sands found at various points across the isles, and in mainland Scotland, Norway, the Faroe Islands and Greenland, proved the tsunami’s towering height, and the event has been well-reported.


Scientists funded by NERC have identified sands on Shetland that they say prove additional tsunamis hit Shetland 5,000 and 1,500 years ago. This could mean that tsunamis are a more common occurrence than previously thought in the UK.


Dr. Sue Dawson from the University of Dundee and Professor Dave Tappin from the British Geological Survey (BGS) are working to identify what could have caused these tsunamis, using new computed tomography (CT) and seismic technology.


Dr. Dawson said: “We found sands aged 5,000 and 1,500 years old at multiple locations in Shetland, up to 13 meters above sea level. These deposits have a similar sediment character as the Storegga event and can therefore be linked to tsunami inundation. We are now using a CT scanning machine at the University of Dundee to look at our samples in detail.”


“For the first time, we’ll have a complete 3-D view of the cores we’ve extracted from the ground and from lochs and seabeds. This detail will show us which direction the wave was travelling in, identify the elements present in the sand, and much more. This will be the first time that such a level of detail has been captured from these prehistoric tsunami events.”


Both scientists agree that a submarine landslide, which is an underwater landslide that moves vast amounts of sediment across the seabed, generated the tsunamis that hit Shetland.


While Dr. Dawson has been investigating the sand samples, Professor David Tappin has been focusing on the seabed to try to pinpoint where the tsunamis originated.











Scientists closing in on source of Shetland tsunamis
Map showing Basta Voe’s depths and yellow pinpoints marking tsunami sands
[Credit: PlanetEarth Online]

Professor Tappin from BGS said: “The younger tsunami sands on Shetland are located quite close together, so we thought the submarine landslide may have originated quite close to the shore. BGS’s research vessel White Ribbon, which can work in the shallowest waters, was used to carry out seismic surveys of the seabed around Shetland, but we have not yet found conclusive proof of submarine landslides there.”


“Identifying landslides on and below the seabed using existing mapping methods is not as straightforward as might be imagined. We plan to test some theoretical models to see if we can reproduce the 1,500 and 5,000 year tsunamis.”


“We will be creating a digital elevation model of the coasts of the Shetlands and the surrounding seabed. We will then reproduce the landslide movement that will generate the tsunami. The numerical model will flood the land and we’ll look at the elevation of the sediments to see if they match with what’s on Shetland. That will take us much closer to finding where the actual tsunamis began.”


“Submarine landslides are much more poorly understood than almost all types of natural hazards, such as river floods or storm surges. But they can be far larger than any landslide seen on land—the Storegga slide contained 300 times the amount of sediment carried each year by all of the world’s rivers combined.”


“Submarine landslides can also occur on slopes of just one or two degrees, and we still don’t know exactly how they are set in motion, except that earthquakes are considered to be the most common trigger. It is critical that we learn more.”


The research is part of the Landslide-Tsunami project, ongoing research that forms a key element of NERC’s Arctic Research Programme. The project aims to discover what causes enormous submarine landslides, what the impact of slides in different locations and of different magnitude would be on the UK, and what the likelihood of such an event might be, given the significant scale of Arctic climate change.


Author: Sarah Mcdaid | Source: PlanetEarth Online [September 18, 2018]



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Six Neolithic sites discovered in western Iran

Head of the archaeology team in Razavar valley river, Shokouh Khosravi, said that archaeological surveys in the area were conducted with the purpose of discovering and identifying areas dating back to the Epipalaeolithic and Neolithic eras.











Six Neolithic sites discovered in western Iran
Credit: IRNA

The Public Relations Office of the Research Institute of Cultural Heritage and Tourism (RICHT) quoted Khosravi as saying that the research work was conducted in line with a survey on tracing environmental and cultural changes of Central Zagros in the mentioned periods for which later a team of Iranian archaeologists accompanied by archeologists from the Copenhagen University was dispatched to the area.


Archaeologists also analyzed patterns for environmental exploitation and assessed the situation of the northern valleys of the Central Zagros region at that time, she said.


Khosravi went on to say that due to the importance of the area and lack of archaeological information in the region, exploration and sound identification of the areas in the valley that are scattered in the landscape of the region was put on the agenda.


The area under study is located between the city of Sahneh in the east, the city of Kamyaran in Kurdestan Province in the north, and among the folds of the Central Zagros and is a long but not so wide plain which is placed in a mountainous and rugged terrain with long, sometimes high, valleys, she noted.


The archaeologist noted that water resources, the old terraces of the river, the caves and rocky sanctuaries, the fertile plain with good soil and the scattered flint resources on the northern slopes of the highlands in the south of the Razavar valley have turned the area into an ideal place for following up the research subject.


Khosravi added that, owing to the size of the region, the explorations of the current season were limited to the extensive terraces of the Razavar river which were formed during the Holocene period and to the rocky areas of the highland foothills on the southern side of the river. As a result six Neolithic sites were identified.


She stated that one of the sites, based on the excavations and soundings, has more than six aceramic (ie. pre-pottery) Neolithic deposits, and is located on the old river terrace with its rich layers of stone artefacts, shells, snails, charcoal and ash.


She further remarked that exploration and identification of a number of caves and rocky sanctuaries in the northern section of the highlands of the southern basin resulted in no finds as all the caves were rocky and devoid of any cultural artefacts since most of them were not formed until after the Pleistocene period.


Source: Islamic Republic News Agency – IRNA [September 19, 2018]



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Completion of the 2018 excavations at Paphos-Toumballos in Cyprus

The Department of Antiquities of Cyprus, Ministry of Transport, Communications and Works, has announced the completion of the 2018 excavations at Pafos-Toumballos. The excavations are conducted by the archaeological mission of the University of Catania, co-directed by Filippo and Elvia Giudice.











Completion of the 2018 excavations at Paphos-Toumballos in Cyprus
Fig. 1: The rocky bank with niches which probably were used to hold lamps
[Credit: Department of Antiquities of Cyprus]

The area under excavation is known as “Garrison’s Camp” and like last year, this year’s fieldwork concentrated on the southern part of the area, where a rocky bank (with an east–west direction) rises from the plain.
In this area, numerous niches were excavated, which probably were used to hold lamps that were offered to the deity worshiped at the sanctuary (Fig.1). The excavations of 2013 and 2017 had revealed two walls, one with a North-South orientation and the other with an East-West one.











Completion of the 2018 excavations at Paphos-Toumballos in Cyprus
Fig. 2: Basin covered with hydraulic mortars [Credit: Department of Antiquities of Cyprus]

These walls delineated the corner of a basin covered with hydraulic mortar (Fig.2). In the same area, a wall consisting of medium-sized stones, barely dressed and held together with lime was excavated.











Completion of the 2018 excavations at Paphos-Toumballos in Cyprus
Fig. 3: Building of the Early Christian period [Credit: Department of Antiquities of Cyprus]

Based on its construction characteristics the wall seems to belong to the Early Christian period, around the 5th century AD. It was excavated at a total length of 11.6 metres, reaching the excavation area’s limits (Fig. 3).











Completion of the 2018 excavations at Paphos-Toumballos in Cyprus
Fig. 4: Rooms of Early Christian house [Credit: Department of Antiquities of Cyprus]

Two other walls (Fig. 4) that were excavated delimit two rooms of a newly discovered Early Christian house. The first room faint traces of ancient flooring comprised of compact beaten earth. Beneath this floor fragments of amphorae, small cups and a small lamp were excavated.
The second room has been only partially explored and does not preserve traces of flooring. In this room a substantial layer of red earth, mixed with small stones was removed in order to reveal a considerable quantity of Late Classical and Hellenistic material (such as, black glazed Attic pottery, mugs, cups with palmette decoration, unguentaria, fragments of Oriental sigillata, amphora handles with stamps and fragments of mold-made glass vessels).











Completion of the 2018 excavations at Paphos-Toumballos in Cyprus
Fig. 4: Hellenistic oil lamp adorned with a head with wavy hair
[Credit: Department of Antiquities of Cyprus]

Among these finds a lamp adorned with a head with wavy hair is worth mentioning (Fig.5). The above material constitutes further evidence of the Hellenistic and Roman periods at the site and especially of life at the pagan sanctuary, located below the Christian archaeological layers. Indeed, it is not unlikely that the entrance to the great pagan sanctuary was in this area.


Source: Press and Information Office, Ministry of Interior, Republic of Cyprus [September 19, 2018]



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Space-Grown Crystals May Lead to More Efficient Drug Development

The International Space

Station
is a perfect environment for

creating protein crystal structures for research.


image

In microgravity, protein molecules

form more orderly, high-quality crystals. Studying these structures helps

scientists understand their function and contributes to development of more

effective treatments for diseases.


image

Experiments often need more than

one try to generate ideal crystals, though. Researchers may have to return

samples to Earth for analysis and then try again on a later mission on the

space station.



Scientists are testing new methods

of growing crystals that allow crew members to observe imperfections, make

real-time adjustments, and try growing them again right away. This dramatically

reduces the time and cost of conducting experiments aboard the space station

and opens up the orbiting lab to more users. More efficient use of time and

resources can produce research results in less time and lead to development of

better drugs sooner.


Learn more @ISS_Research!


New study identifies possible ancestors of RNA

Researchers from the Georgia Institute of Technology may have made headway in helping determine the origin of life by identifying three different molecules that self-assemble to form a molecular structure with features characteristic of modern RNA.











New study identifies possible ancestors of RNA
Which molecules formed RNA, and can we use them to identify where life may form in the universe?
[Credit: NASA/Jenny Mottar]

RNA – or ribonucleic acid – carries out the instructions coded in DNA, but is also thought to have developed before DNA. Many scientists believe nucleic acids – the ‘NA’ of ‘RNA’ – played a key role in the origin of life. A popular theory called the ‘RNA World’ holds that RNA ‘invented’ proteins and eventually DNA, but that begs the question, where did RNA come from? Some believe a chemical or biological process gradually evolved an earlier molecule into RNA, while others chalk it up to some kind of non-enzymatic, geochemical reaction. It’s a chicken-or-egg debate: what biological process could produce a central building block for life itself? If the process wasn’t biological, then what was it and how did it happen?
The new study continues in the tradition of the 1953 Miller–Urey experiment, in which two scientists modeled early-Earth’s conditions with a mixture of gases and an electric current to simulate lightning. That experiment yielded amino acids, supporting the idea that biological molecules can spontaneously emerge from non-biological ones in the right circumstances. Despite that finding, the challenge of devising a scenario in which non-biological reactions create RNA has thus far proven insurmountable.


RNA’s origins lost in the mists of time


One of the study’s authors, biochemist Dr. Nicholas Hud, notes that the many criteria of RNA formation often means that when researchers propose a solution to one problem, a different problem (or two) arises. The links of the RNA chain, which are called nucleotides, are comprised of four bases: adenine (A), cytosine (C), guanine (G) and uracil (U), as well as a phosphate and a ribose sugar. Leslie Orgel, who was a pioneer of the RNA World idea, described the possibility that RNA evolved from an earlier molecule a “gloomy prospect,” as it would make solving the origin of RNA harder. The researchers decided it was time to face that challenge.


A re-analysis in 2008 of the Miller–Urey experiment reveals the production of far more non-biological molecules than previously thought, which underpins the authors’ hypothesis that molecules necessary for life existed on prebiotic Earth, but because they don’t play a major role in life as we now know it, we haven’t figured out which molecules or the roles they played all those billions of years ago.


According to Hud, those molecules were “probably very special because the molecules we know of don’t behave in ways that indicate they’re able to to start life.” Those molecules may also contain answers to other questions about life’s origins.











New study identifies possible ancestors of RNA
Side-by-side comparison of RNA and DNA for context [Credit: WikiCommons/Sponk]

The evolution to RNA from an earlier genetic molecule, or proto-RNA, would have been incremental, and each new iteration would have been backward compatible, “like how an updated computer still has to be able to read files from older computers,” Hud tells Astrobiology Magazine. Today RNA and DNA use hydrogen-bonded base-pairs to transfer information. Thus, the molecules that don’t form the same or similar base-pairs wouldn’t have ever worked, leading the researchers to search for “base-pairing molecules that would self-select or segregate themselves on the early Earth into some kind of structure that would help them be incorporated into proto-RNA,” says Hud.


The search for the original molecules


What were those primordial molecules that formed the ancestor of RNA? To determine this, the researchers studied reactions in conditions that mimicked rain and evaporation cycles on the early Earth. After many unsuccessful experiments, they identified three molecular candidates for the bases of proto-RNA: barbituric acid,melamine, and 2, 4, 6-triaminopyrimidine. Reactions with these molecules and the ribose sugar produced nucleosides, which are composite molecules that are close to the sub-units of RNA.


Whereas previous attempts to join the current bases of RNA with ribose in early Earth reactions that were modeled either failed, or produced nucleosides in only very low yields, the researchers measured an 82% nucleoside yield with barbituric acid. Additionally, melamine and the triaminoprymidine molecules spontaneously formed nucleosides in over 50% yields. Dr. Niles Lehman, Professor of Chemistry at Portland State University and Editor-in-Chief of the Journal of Molecular Evolution, believes that the study “provides further support for the RNA World theory by providing a plausible series of events that took nature from chemical chaos to a more defined storage information molecule.”


That path isn’t completely clear, but it’s starting to take shape. According to Hud, their candidates for the ancestral bases of RNA are tantalizingly close to those of modern RNA. However, more needs to happen.


“The molecules we have identified look like they could have functioned in an early genetic system,” Hud says. “But we want molecules close enough that you can imagine an evolutionary path where they change into what we have today.” While demonstrable plausibility represents a step forward, the question remains whether it’s possible to find, and then confirm, the original proto-RNA molecules. Hud acknowledges that while the search might seem daunting, “chemistry is vast, but not infinite. If we accept a few reasonable assumptions about the ancestor of RNA, we can rule out a lot of possibilities. And maybe we can find it.” This study represents an important step down that path.


Origins of life elsewhere


Figuring out how RNA formed could help guide the search for extraterrestrial life. “We can gain valuable insight into key problems that need to be overcome for life to arise from non-life,” Lehman tells Astrobiology Magazine.


Understanding how life arises could help scientists determine where and how to look for life elsewhere. Amino acids and chemical compounds such as hydrogen cyanide, which has been detected in comets, could give rise to RNA bases, according to Hud. Such a reaction would be “robust, not strange or extraordinary,” he says. Similar processes could be underway on other planets and could point to the chemistry scientists should look for when searching for the earliest stages of life elsewhere.


Author: Joelle Renstrom | Source: Astrobiology Magazine [September 16, 2018]



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