среда, 16 января 2019 г.

2019 January 16 IC 342: The Hidden Galaxy Image Credit &…

2019 January 16

IC 342: The Hidden Galaxy
Image Credit & Copyright: Arturas Medvedevas

Explanation: Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant in the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and dust clouds along the plane of our own Milky Way galaxy. Even though IC 342’s light is dimmed and reddened by intervening cosmic clouds, this sharp telescopic image traces the galaxy’s own obscuring dust, young star clusters, and glowing pink star forming regions along spiral arms that wind far from the galaxy’s core. IC 342 may have undergone a recent burst of star formation activity and is close enough to have gravitationally influenced the evolution of the local group of galaxies and the Milky Way.

∞ Source: apod.nasa.gov/apod/ap190116.html

Oceans are warming even faster than previously thought

Berkeley — Heat trapped by greenhouse gases is raising ocean temperatures faster than previously thought, concludes an analysis of four recent ocean heating observations. The results provide further evidence that earlier claims of a slowdown or “hiatus” in global warming over the past 15 years were unfounded.

Oceans are warming even faster than previously thought
A new analysis shows that ocean temperatures are on the rise — and they are going up faster than once thought
[Credit: University of California – Berkeley]

“If you want to see where global warming is happening, look in our oceans,” said Zeke Hausfather, a graduate student in the Energy and Resources Group at the University of California, Berkeley, and co-author of the paper. “Ocean heating is a very important indicator of climate change, and we have robust evidence that it is warming more rapidly than we thought.”

Ocean heating is critical marker of climate change because an estimated 93 percent of the excess solar energy trapped by greenhouse gases accumulates in the world’s oceans. And, unlike surface temperatures, ocean temperatures are not affected by year-to-year variations caused by climate events like El Nino or volcanic eruptions.

The new analysis, published in Science, shows that trends in ocean heat content match those predicted by leading climate change models, and that overall ocean warming is accelerating.

Assuming a “business-as-usual” scenario in which no effort has been made to reduce greenhouse gas emissions, the Coupled Model Intercomparison Project 5 (CMIP5) models predict that the temperature of the top 2,000 meters of the world’s oceans will rise 0.78 degrees Celsius by the end of the century. The thermal expansion caused by this bump in temperature would raise sea levels 30 centimeters, or around 12 inches, on top of the already significant sea level rise caused by melting glaciers and ice sheets. Warmer oceans also contribute to stronger storms, hurricanes and extreme precipitation.

“While 2018 will be the fourth warmest year on record on the surface, it will most certainly be the warmest year on record in the oceans, as was 2017 and 2016 before that,” Hausfather said. “The global warming signal is a lot easier to detect if it is changing in the oceans than on the surface.”

The four studies, published between 2014 and 2017, provide better estimates of past trends in ocean heat content by correcting for discrepancies between different types of ocean temperature measurements and by better accounting for gaps in measurements over time or location.

“The Intergovernmental Panel on Climate Change’s (IPCC) Fifth Assessment Report, published in 2013, showed that leading climate change models seemed to predict a much faster increase in ocean heat content over the last 30 years than was seen in observations,” Hausfather said. “That was a problem, because of all things, that is one thing we really hope the models will get right.”

“The fact that these corrected records now do agree with climate models is encouraging in that is removes an area of big uncertainty that we previously had,” he said.

Deep Divers

A fleet of nearly 4,000 floating robots drift throughout the world’s oceans, every few days diving to a depth of 2000 meters and measuring the ocean’s temperature, pH, salinity and other bits of information as they rise back up. This ocean-monitoring battalion, called Argo, has provided consistent and widespread data on ocean heat content since the mid-2000s.

Prior to Argo, ocean temperature data was sparse at best, relying on devices called expendable bathythermographs that sank to the depths only once, transmitting data on ocean temperature until settling into watery graves.

Three of the new studies included in the Science analysis calculated ocean heat content back to 1970 and before using new methods to correct for calibration errors and biases in the both the Argo and bathythermograph data. The fourth takes a completely different approach, using the fact that a warming ocean releases oxygen to the atmosphere to calculate ocean warming from changes in atmospheric oxygen concentrations, while accounting for other factors, like burning fossil fuels, that also change atmospheric oxygen levels.

“Scientists are continually working to improve how to interpret and analyze what was a fairly imperfect and limited set of data prior to the early 2000s,” Hausfather said. “These four new records that have been published in recent years seem to fix a lot of problems that were plaguing the old records, and now they seem to agree quite well with what the climate models have produced.”

Author: Kara Manke | Source: University of California – Berkeley [January 10, 2019]



Bizarre ‘bristle-jaw’ creatures finally placed on tree of life

Chaetognaths, whose name means “bristle-jaw,” can be found all over world, swimming in brackish estuaries, tropical seas and above the deep dark ocean floor. Also known as arrow worms, the creatures have been around since the Cambrian Period, but their precise place in evolutionary history has long eluded scientists. Now, researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) have learned where arrow worms wiggle on the Tree of Life, and their results could reveal important trends in the evolution of bilateral organisms.

Bizarre 'bristle-jaw' creatures finally placed on tree of life
Chaetognaths, or arrow worms, have a distinct jaw structure composed of dense protein matrix
and a fibrous substance called chitin. These organisms display an ambiguous set of developmental
and morphological features, making them difficult to categorize on the Tree of Life
 [Credit: Creative Commons]

The researchers sought to verify the relationship of the predatory arrow worm to other spiralia — members of a diverse group of organisms, or clade, believed to share a common ancestor. The spiralian clade includes mollusks, segmented worms and flatworms. Strikingly, the scientists found that arrow worms don’t belong with spiralians, but instead with a new group of animals that form a sister group to the clade. The results, published in Current Biology, challenge the classical view that complex organisms evolved from simple ancestors by gaining new traits over time.

“Arrow worms are predators, they have nervous systems, they have developed sensory organs. But the other organisms they’re grouped with are much simpler,” said Ferdinand Marlétaz, first author of the study and a postdoctoral scholar in the OIST Molecular Genetics Unit, led by Prof. Daniel Rokhsar. “If you place arrow worms here, it means there was probably a lot of independent simplification, rather than the independent emergence of complexity.”

Though very different in appearance, arrow worms and their phylogenetic relatives, such as the microscopic animals known as rotifers, seem to share a unique jaw structure. Composed of dense protein matrix and a fibrous substance called chitin, these jaws are situated near the organisms’ mouths and allow them to grasp their prey.

“Arrow worms group with a fairly obscure collection of small marine animals — they’re not animals most people are familiar with,” said Prof. Daniel Rokhsar, senior author of the study and principal investigator of the research unit. “The fact that these different animals had jaws that were probably related to each other wasn’t clear until this paper.”

Arrow worms from around the world

The roughly 200 species of arrow worms resemble tiny spears and range from only one millimeter long to 12 centimeters in length. The predators mostly feast on small crustaceans called copepods, using their keen vibratory sense to hunt prey and swallow them whole. The weird worm-like creatures actually share many morphological and developmental traits with other organisms, which makes their evolutionary timeline difficult to trace.

“Different animals that share the same early development are often related to each other,” said Rokhsar. One reason researchers have struggled to characterize arrow worms is that their early developmental patterns are ambiguous; they resemble patterns observed in two major groups of animals. “We really had no way of precisely classifying arrow worms one way or the other.”

The two animal supergroups are known as deuterostomes and protostomes. Both sets of organisms have a single gut running through them, from their mouths to the other end. In early development, the deuterostome gut forms from the bottom up, while protostome gut formation starts at the mouth. Though arrow worms develop bottom-up like deuterostomes, they strongly resemble protostomes both morphologically and genetically.

To clear up this discrepancy, the researchers gathered data from 10 arrow worm species and compared it to publicly available data from other animals. They examined the species transcriptomes, which serve as a snapshot of all the genes being expressed in a given cell. The scientists originally plucked their sample arrow worms from the Atlantic Ocean, the Gullmarfjord in Sweden, the Amakusa in Japan and Marseille in France. Dr. Katja Peijnenburg from Amsterdam University, Dr. Taichiro Goto from Mie University, and Prof. Noriyuki Satoh of the OIST Marine Genomics Unit assisted Marlétaz in collecting and preparing the samples.

The comparison placed arrow worms solidly in the protostome superclade within a subgroup that includes microscopic organisms known as rotifers, gnathostomulids, and micrognathozoans. Other established subgroups were shuffled around as an unintended consequence of this grouping, meaning many relationships among protostomes are now under scrutiny.

“I was a little bit surprised,” said Marlétaz. “We still don’t fully understand this association with rotifers and the others. That will be the focus of future research.”

Protostomes, past and future

The study improved on earlier work by collecting the new arrow worm data and comparing it to a representative sample of other members of the animal kingdom. The researchers also chose to focus on evolutionary lineages that had evolved relatively slowly, rather than quickly. Fast-evolving lineages tend to appear similar in analysis, even if they are barely related, so the researchers sought to avoid this bias.

Looking forward, Marlétaz hopes there will be more morphological studies of arrow worms, to connect the dots between the animals’ phylogeny and their physical characteristics. For instance, the researchers don’t yet know what genes give rise to the iconic “bristle jaw” of the Gnathifera clade, or what other specific feature might unite the group.

“We also need to look closer at the arrow worm genome,” said Marlétaz. “Arrow worms have very original genomic features, so we want to understand that better in the context of their new phylogenetic position.”

Author: Nicoletta Lanese | Source: Okinawa Institute of Science and Technology [January 10, 2019]



Station Trio Practices Emergency Before Radiation, Physics Research

ISS – Expedition 58 Mission patch.

January 15, 2019

The Expedition 58 crew members started Tuesday with an emergency drill before splitting up for more space research and hardware maintenance.

Commander Oleg Kononenko led Flight Engineers Anne McClain and David Saint-Jacques through a simulated emergency this morning aboard the International Space Station. The trio practiced communication and coordination with Mission Control Centers in Houston and Moscow.

Image above: The SpaceX Dragon cargo craft begins its departure from the space station Jan. 13, 2019, moments after being released from the grips of the Canadarm2 robotic arm. Image Credit: NASA.

The unlikely emergency scenarios the crew trains for include events such as depressurization, ammonia leaks and fires. Responses include quickly donning safety gear, closing a module hatch to isolate pressure and ammonia leaks, extinguishing a fire and evacuating the station aboard the Soyuz crew ship.

McClain then moved on to cable and parts work on the Multi-Purpose Small Payload Rack (MSPR) that can house a variety of smaller experiments. She wrapped up the day photographing Saint-Jacques as he installed neutron detectors for an experiment to understand how space radiation impacts astronauts.

International Space Station (ISS). Image Credits: NASA7STS-130

Kononenko worked today on the Electromagnetic Levitator that exposes materials to extremely high temperatures to explore their thermo-physical properties in the microgravity environment. The four-time station cosmonaut later went on to routine maintenance on life support systems in the orbital lab’s Russian segment.

Related links:

Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html

Multi-Purpose Small Payload Rack (MSPR): https://www.nasa.gov/mission_pages/station/research/experiments/1203.html

Neutron detectors: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=874

Electromagnetic Levitator: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1853

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

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

Images (mentioned), Text, Credits: NASA/Mark Garcia.

Greetings, Orbiter.chArchive link

Responses of benthic foraminifera to changes of temperature and salinity

Benthic foraminifera are widely used as paleoenvironmental proxies because of their high sensitivity to environmental changes and excellent preservation potential in sediment. Affected by global changes, environmental factors such as seawater temperature and salinity are changing, which will affect the distribution and species composition of benthic foraminifera. A recent study revealed how the benthic foraminiferal community respond to the change of temperature and salinity.

Responses of benthic foraminifera to changes of temperature and salinity
Micrographs of benthic foraminifera from culture experiment
[Credit: : © Science China Press]

This study is published in the journal Science China Earth Sciences with title ‘Responses of benthic foraminifera to changes of temperature and salinity: Results from a laboratory culture experiment’. Prof. Yanli LEI from Institute of Oceanology Chinese Academy of Sciences is corresponding authors of this article. Through laboratory culture experiment, the researchers only changed the temperature and salinity, while controlling other environmental parameters consistent. They conducted a two-factor crossed experiment in which foraminiferal communities were cultured at different temperatures (6, 12, and 18°C) and salinities (15, 20, 25, and 30 psu) for 10 weeks. The research revealed the different response of benthic foraminifera communities to the change of temperature and salinity.

Scientist knows little about the response of benthic foraminifera to environmental factors. Environmental factors are not independent, and the responses of foraminifera usually reflect the combined effects of the measured environmental factors and other unknown biotic and abiotic factors in the field. Therefore, it is difficult to discern cause-effect relationships between environmental factors and changes in benthic foraminiferal community in field studies, especially with interactive effects.

To solve this problem, laboratory-controlled culture methods were used in this study. The researchers cultured the entire foraminiferal communities with the natural sediments from the intertidal area of Qingdao Bay for 10 weeks. They analyzed and compared the foraminiferal community under different conditions of temperature and salinity. The study showed that temperature affected foraminiferal community more significantly than salinity. In addition, with increasing temperature, the species composition shifted from hyaline taxon to porcellaneous taxon.

This study indicates that the benthic foraminiferal community is very sensitive to the change of environmental factors (e.g., temperature and salinity) and it can be used to indicate the changes in the marine ecosystem. At the same time, this finding has important scientific significance and reference value for reconstructing the paleoenvironment by using benthic foraminiferal community composition.

Source: Science China Press [January 11, 2019]



A new mechanism helps explain differences between eukaryotic and bacterial proteomes

What makes distinct species have different proteins? Is there a key that allows eukaryotic cells to produce proteins involved in multicellularity that are mostly absent in prokaryotes?

A new mechanism helps explain differences between eukaryotic and bacterial proteomes
Maximum likelihood phylogenetic tree based on ADAT2 and ADAT3 amino acid sequences
[Credit: Molecular Biology and Evolution]

These are some of the questions addressed by the scientists headed by ICREA researcher Lluís Ribas, group leader of the Gene Translation lab at the Institute for Research in Biomedicine (IRB Barcelona). Their work has led to the discovery of a mechanism that allows eukaryotic cells to synthesize proteins that bacteria find hard to produce.

Published recently in the journal Molecular Biology and Evolution, the study has been done in collaboration with the team headed by Iñaki Ruiz-Trillo, ICREA researcher at the Institute of Evolutionary Biology in Barcelona.

“We discovered and described a mechanism evolved in eukaryotes that facilitates the synthesis of large, unstructured proteins such as those present in the extracellular matrix. Those are the proteins that surround each cell and allow them to associate and communicate with their environment” says Lluís Ribas.

The results of the research explain that the emergence of this functional improvement in some transfer RNAs (tRNA) facilitated the synthesis of proteins highly enriched in a specific set of amino acids, and drove an enrichment of genes coding for these tRNAs in eukaryotic genomes.

Many of these proteins are highly relevant to human health, and understanding the mechanisms essential to their synthesis may allow the development of strategies to inhibit their production in those diseases caused by their overabundance.

Source: Institute for Research in Biomedicine (IRB Barcelona) [January 11, 2019]



Skull scans tell tale of how world’s first dogs caught their prey

Analysis of the skulls of lions, wolves and hyenas has helped scientists uncover how prehistoric dogs hunted 40 million years ago.

Skull scans tell tale of how world's first dogs caught their prey
Computerised scan of skull of first dog species – Hesperocyon gregarius – with inner ear
highlighted in red [Credit: Julia Schwab]

A study has revealed that the first species of dog — called Hesperocyon gregarius — pounced on its prey in the same way that many species, including foxes and coyotes, do today.

The findings also show that the largest dog species ever to live — known as Epicyon haydeni — hunted in a similar way. The animals — which lived from 16 until seven million years ago — could grow to the size of a grizzly bear.

Comparisons between computerised scans of fossils and modern animals have shed light on the hunting methods used by prehistoric members of a group of mammals known as carnivorans. These include modern-day foxes, wolves, cougars and leopards.

Scientists at the Universities of Edinburgh and Vienna used the scans to create digital models of the inner ears of 36 types of carnivoran, including six extinct species.

The team found that the size of three bony canals in the inner ear — the organ that controls balance and hearing — changed over millions of years as animals adopted different hunting styles.

Faster predators — such as cheetahs, lions and wolves — developed large ear canals that enable them to keep their head and vision stable while ambushing or chasing prey at speed, the team says.

Their findings reveal that inner ear structure indicates whether a species descended from dog-like animals or belongs to one of four families of animals resembling cats. A distinctive angle between two parts of the inner ear is much larger in dog-like animals, the team found.

The study is based on research carried out by Julia Schwab, a current PhD student at the University of Edinburgh, during her MSc studies at the University of Vienna, Austria. It is published in the journal Scientific Reports.

Ms Schwab, based in the University of Edinburgh’s School of GeoSciences, said: “For me, the inner ear is the most interesting organ in the body, as it offers amazing insights into ancient animals and how they lived. The first dog and the largest-ever dog are such fascinating specimens to study, as nothing like them exists in the world today.”

Source: University of Edinburgh [January 11, 2019]



Plant phytolith and water content influence rate of tooth enamel abrasion in vertebrates

Plant phytolith and water content cause differing degrees of tooth enamel abrasion in vertebrates. This is the conclusion reached by an international research team headed by scientists from Johannes Gutenberg University Mainz (JGU). Their study, featured online before print in Proceedings of the National Academy of Sciences, has implications for how tooth wear in extinct animals is interpreted and how this information can be employed to reconstruct their dietary behaviour and habitats.

Plant phytolith and water content influence rate of tooth enamel abrasion in vertebrates
The surface of guinea pig teeth under the microscope, showing abrasion caused by forage plants
[Credit: Daniela E. Winkler]

In their study, the researchers were able to demonstrate that tooth enamel is abraded more rapidly when plants with a higher phytolith content, such as grass, are consumed rather than those with a low phytolith content, such as alfalfa.

Phytoliths are microscopic mineral inclusions made of silica dioxide that are present in many plants. Although phytoliths are softer than tooth enamel, scientists have been uncertain whether tooth abrasion is mainly caused by phytoliths within the plants or mineral particles and sand adhering to the surface of of the plants.

To evaluate the abrasive effect of phytoliths, six groups of guinea pigs in the University of Zurich’s Clinic for Zoo Animals, Exotic Pets and Wildlife were fed for three weeks with three different fresh or dried plants (alfalfa, grass, and bamboo). The plants fed to the guinea pigs had varying levels of phytolith content, ranging from 0.5 to 3 percent, but were otherwise free of any adhering particles.

The surface topography of the enamel of the guinea pigs’ molars was then examined using high-resolution microscopy. This revealed that abrasion was more extensive with increasing phytolith content of the feed.

In addition, it was also observed that the water content of the plants plays a role. In the study, the researchers systematically analyzed the abrasive properties of fresh and dry plants with different phytolith contents. They determined that dry feed results in greater tooth wear than the equivalent fresh feed.

“The enamel of the guinea pigs we had fed on dry grass was much more worn and rougher than the enamel of the animals that had been given fresh, and therefore moister, grass,” said Dr. Daniela Winkler, head of the study at the Institute of Geosciences at JGU.

Remarkably, however, there were no differences in tooth surface texture in the case of guinea pigs that had eaten fresh or dried alfalfa and those that had eaten fresh grass.

“While there is a similarly low level of wear following consumption of alfalfa and damp grass, the landscapes in which alfalfa or grass grow can differ greatly,” Winkler pointed out. “This may indicate a potential source of error in how paleontologists have been using tooth abrasion to reconstruct herbivore diets and habitats,” said Winkler.

“We often try to deduce what the habitats of the corresponding animals were like by analyzing the abrasion of their fossilized teeth. Less abrasion, for instance, indicates that the animal might have lived in a wooded landscape with lots of herbage and foliage, rather than in a steppe-like environment dominated by grasses.

Furthermore, the surface textures of teeth of fresh grass grazers may resemble those of leaf eaters. We need to bear these findings in mind when reconstructing the diet of extinct animals on the basis of their fossil teeth,” concluded Winkler.

Source: Johannes Gutenberg Universitaet Mainz [January 11, 2019]



Conservation work begins on medieval Dutch trade ship

Conservation work on a 14th century ship found near Kampen on the river IJssel has started this week after a storm early last year demolished the roof of the conservation station.

Conservation work begins on medieval Dutch trade ship
The IJsselkogge was raised from the river bed in 2016 after being discovered in 2011 
[Credit: © Freddy Schinkel]

The IJsselkogge, one of a fleet of 100 trade ships belonging to the Hanseatic city of Kampen, was raised from the river bed in 2016 after being discovered in 2011.
Although the ship was not completely dismantled, archaeologists think the 20 meter long ship was sunk, along with two smaller vessels, to prevent sand from building up in the river and blocking what was a vital waterway in the Hanseatic trade network.

Conservation work begins on medieval Dutch trade ship
Work on the ship has started [Credit: Batavialand]

The find is considered to be a unique one which underlines Kampen’s importance as a trade link in the Middle Ages.
The ship’s length indicates it was a sea-going vessel which would have transported wood and cereals from the countries around the Baltic Sea, salt and wine from France, beer from Germany, herring from Sweden and wool from Britain.

Cogs played a vital part in Medieval transport because of their superior design which allowed them to better weather storms and keep on course.

The ship, which was transported to Dutch heritage site and museum Batavialand in Lelystad, will undergo a special wood preservation process there which will take six years to complete. It will then go on show at the site.

Source: Dutch News [January 11, 2019]



Ancient tomb group unearthed in Shaanxi

Archaeologists in northwest China’s Shaanxi Province said Friday they have discovered an ancient tomb group dating back more than 1,500 years in a village in the province.

Ancient tomb group unearthed in Shaanxi
Archaeologists with the Shaanxi Academy of Archaeology have excavated a cluster of 12 tombs dating back
to the Sixteen Kingdoms (304-439 AD) from 2017 to 2018 in Leijia Village of Xixian New Area,
along with sacrificial sites and millet [Credit: Xinhua]

Archaeologists with the Shaanxi Academy of Archaeology said that a cluster of 12 tombs dating back to the Sixteen Kingdoms (304-439 AD) was excavated from 2017 to 2018 in Leijia Village of Xixian New Area, along with sacrificial sites and millet.
The tombs are laid out in two rows, and each tomb consists of a tomb passage, a door and a path leading to the coffin chamber, according to Liu Daiyun, a researcher with the academy.

Ancient tomb group unearthed in Shaanxi

Ancient tomb group unearthed in Shaanxi
Earthenware figurines unearthed from a tomb dating back to the Sixteen Kingdoms (304-439 AD) in Leijia Village
of Xixian New Area, northwest China’s Shaanxi Province [Credit: Xinhua]

“Some new burial customs, such as placing stones in a small pit at the corner of the tomb and the feet of some of the bodies in the tombs being held down by square stones, have been discovered for the first time,” Liu said.
The majority of the burial objects were pottery ware, including figurines of warriors, servants and animals, jars and lamps. Some bronze accessories such as mirrors, stamps, hair clasps and pins, bracelets and bells and several kinds of bronze coins were unearthed.

Ancient tomb group unearthed in Shaanxi
Bronze ware unearthed from a tomb dating back to the Sixteen Kingdoms (304-439 AD) in Leijia Village
of Xixian New Area, northwest China’s Shaanxi Province
 [Credit: Xinhua]

Among these coins, a rare coin cast in the Later Zhao, one of the kingdoms during this period, was an important reference for archaeologists to determine the date of the tombs, Liu said.
Archaeologists also found skulls of piglets in two tombs and a large amount of weathered millet shell.

Ancient tomb group unearthed in Shaanxi
Bronze seal unearthed from a tomb dating back to the Sixteen Kingdoms (304-439 AD)
in Leijia Village of Xixian New Area, northwest China’s Shaanxi Province
[Credit: Xinhua]

Ancient tomb group unearthed in Shaanxi
Earthenware lamp unearthed from a tomb dating back to the Sixteen Kingdoms (304-439 AD)
 in Leijia Village of Xixian New Area, northwest China’s Shaanxi Province
[Credit: Xinhua]

“Based on the distribution of the tombs, it can be determined that the tombs belonged to a family. We will further determine the relationships of the tomb owners through DNA tests,” Liu added.

Source: Xinhua [January 11, 2019]



What 100,000 Star Factories in 74 Galaxies Tell Us about Star Formation across the...


Six ALMA-imaged galaxies out of a collection of the 74. The images were taken as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton. Hi-res image

ALMA image of galaxy NGC 4321, also known as Messier 100, an intermediate spiral galaxy located about 55 million light-years from Earth in the constellation Coma Berenices. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton. Hi-res image

ALMA image of NGC 628, also known as Messier 74, a spiral galaxy in the constellation Pisces, located approximately 32 million light-years from Earth. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: ALMA (ESO/NAOJ/NRAO); NRAO/AUI/NSF, B. Saxton. Hi-res image

Composite ALMA (orange) and Hubble (blue) image of NGC 628, also known as Messier 74, a spiral galaxy in the constellation Pisces, located approximately 32 million light-years from Earth. It is imaged as part of the PHANGS-ALMA survey to study the properties of star-forming clouds in disk galaxies. Credit: NRAO/AUI/NSF, B. Saxton: ALMA (ESO/NAOJ/NRAO); NASA/Hubble. Hi-res image

Galaxies come in a wide variety of shapes and sizes. Some of the most significant differences among galaxies, however, relate to where and how they form new stars. Compelling research to explain these differences has been elusive, but that is about to change. The Atacama Large Millimeter/submillimeter Array (ALMA) is conducting an unprecedented survey of nearby disk galaxies to study their stellar nurseries. With it, astronomers are beginning to unravel the complex and as-yet poorly understood relationship between star-forming clouds and their host galaxies.

A vast, new research project with ALMA, known as PHANGS-ALMA (Physics at High Angular Resolution in Nearby GalaxieS), delves into this question with far greater power and precision than ever before by measuring the demographics and characteristics of a staggering 100,000 individual stellar nurseries spread throughout 74 galaxies.

PHANGS-ALMA, an unprecedented and ongoing research campaign, has already amassed a total of 750 hours of observations and given astronomers a much clearer understanding of how the cycle of star formation changes, depending on the size, age, and internal dynamics of each individual galaxy. This campaign is ten- to one-hundred-times more powerful (depending on your parameters) than any prior survey of its kind.

“Some galaxies are furiously bursting with new stars while others have long ago used up most of their fuel for star formation. The origin of this diversity may very likely lie in the properties of the stellar nurseries themselves,” said Erik Rosolowsky, an astronomer at the University of Alberta in Canada and a co-Principal Investigator of the PHANGS-ALMA research team.

He presented initial findings of this research at the 233rd meeting of the American Astronomical Society being held this week in Seattle, Washington. Several papers based on this campaign have also been published in the Astrophysical Journal and the Astrophysical Journal Letters. 

“Previous observations with earlier generations of radio telescopes provide some crucial insights about the nature of cold, dense stellar nurseries,” Rosolowsky said. “These observations, however, lacked the sensitivity, fine-scale resolution, and power to study the entire breadth of stellar nurseries across the full population of local galaxies. This severely limited our ability to connect the behavior or properties of individual stellar nurseries to the properties of the galaxies that they live in.”

For decades, astronomers have speculated that there are fundamental differences in the way disk galaxies of various sizes convert hydrogen into new stars. Some astronomers theorize that larger, and generally older galaxies, are not as efficient at stellar production as their smaller cousins. The most logical explanation would be that these big galaxies have less efficient stellar nurseries. But testing this idea with observations has been difficult.

For the first time, ALMA is allowing astronomers to conduct the necessary wide-ranging census to determine how the large-scale properties (size, motion, etc.) of a galaxy influence the cycle of star formation on the scale of individual molecular clouds. These clouds are only about a few tens to a few hundreds of light-years across, which is phenomenally small on the scale of an entire galaxy, especially when seen from millions of light-years away.

“Stars form more efficiently in some galaxies than others, but the dearth of high-resolution, cloud-scale observations meant our theories were weakly tested, which is why these ALMA observations are so critical,” said Adam Leroy, an astronomer at The Ohio State University and co-Principal Investigator on the PHANGS-ALMA team.

Part of the mystery of star formation, the astronomers note, has to do with the interstellar medium – all the matter and energy that fills the space between the stars.

Astronomers understand that there is an ongoing feedback loop in and around the stellar nurseries. Within these clouds, pockets of dense gas collapse and form stars, which disrupts the interstellar medium.

“Indeed, comparing early PHANGS observations with the locations of newly formed stars shows that the newly formed stars quickly destroy their birth clouds,” said Rosolowsky. “The PHANGS team is studying how this disruption plays out in different types of galaxies, which may be a key factor in star-forming efficiency.”

For this research, ALMA is observing molecules of carbon monoxide (CO) from all relatively massive, generally face-on spiral galaxies visible from the Southern Hemisphere. Molecules of CO naturally emit the millimeter-wavelength light that ALMA can detect. They are particularly effective at highlighting the location of star-forming clouds.

“ALMA is a stunningly efficient machine to map carbon monoxide over large areas in nearby galaxies,” said Leroy. “It was able to perform this survey because of the combined power of the 12-meter dishes, which study fine-scale features, and the smaller, 7-meter dishes at the center of the array, which are sensitive to large-scale features, essentially filling in the gaps.”

A companion survey, PHANGS-MUSE, is using the Very Large Telescope to obtain optical imaging of the first 19 galaxies observed by ALMA. MUSE stands for the Multi-Unit Spectroscopic Explorer. Another survey, PHANGS-HST uses the Hubble Space Telescope to survey 38 of these galaxies to find their youngest stellar clusters. Together, these three surveys give a startlingly complete picture of how well galaxies form stars by probing cold molecular gas, its motion, the location of ionized gas (regions where stars are already forming), and the galaxies’ complete stellar populations.

“In astronomy, we have no ability to watch the cosmos change over time; the timescales simply dwarf human existence,” noted Rosolowsky. “We can’t watch one object forever, but we can observe hundreds of thousands of star-forming clouds in galaxies of different sizes and ages to infer how galactic evolution works. That is the real value of the PHANGS-ALMA campaign.”

“We also look at thousands to tens of thousands of star-forming regions within each galaxy, catching them across their life cycle. This lets us build a picture of the birth and death of stellar nurseries across galaxies, something almost impossible before ALMA,” added Leroy.

So far, PHANGS-ALMA has studied about 100,000 Orion Nebula-like objects in the nearby universe. It is expected that the campaign will eventually observe around 300,000 star-forming regions.

Additional Information

These results are being published in a series of papers in the Astrophysical Journal and the Astrophysical Journal Letters. Already accepted and published:

“Cloud-scale Molecular Gas Properties in 15 Nearby Galaxies,” J. Sun, et al., 2018 June. 25, Astrophysical Journal [http://iopscience.iop.org/article/10.3847/1538-4357/aac326]

“Star Formation Efficiency per Free-fall Time in nearby Galaxies,” D. Utomo, et al., 2018 July 11, Astrophysical Journal Letters [http://iopscience.iop.org/article/10.3847/2041-8213/aacf8f/meta]

“A 50 pc Scale View of Star Formation Efficiency across NGC 628,” K. Kreckel, et al., 2018 August 14, Astrophysical Journal Letters [http://iopscience.iop.org/article/10.3847/2041-8213/aad77d]

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) in Taiwan and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.


Nicolás Lira
Education and Public Outreach Coordinator
Joint ALMA Observatory, Santiago – Chile
Phone: +56 2 2467 6519
Cell phone: +56 9 9445 7726
Email: nicolas.lira@alma.cl

Charles E. Blue
Public Information Officer
National Radio Astronomy Observatory Charlottesville, Virginia – USA
Phone: +1 434 296 0314
Cell phone: +1 202 236 6324
Email: cblue@nrao.edu

Calum Turner
ESO Assistant Public Information Officer
Garching bei München, Germany
Phone: +49 89 3200 6670
Email: calum.turner@eso.org

Masaaki Hiramatsu
Education and Public Outreach Officer, NAOJ Chile
, Tokyo – Japan
Phone: +81 422 34 3630
Email: hiramatsu.masaaki@nao.ac.jp

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Moel Goedog Ring Cairn 1, Moel Goedog Prehistoric Complex, Harlech, North Wales, 4.1.19.

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How the Arabian oryx was brought back from extinction

More than four decades ago, the Arabian oryx was extinct in the wild. But today, thanks to efforts spearheaded by Saudi Arabia and the UAE, experts are citing the swell in its numbers as one of the world’s biggest conservation success stories.

How the Arabian oryx was brought back from extinction
There are now an estimated 1,220 wild oryx across the Arabian Peninsula
[Credit: Shutterstock]

In the early 1970s, the antelope was considered all but vanished due to hunting and poaching. Now it is not only back from the brink, but in 2011 the International Union for the Conservation of Nature (IUCN) reclassified it to “vulnerable” from “endangered,” the first time a species that was once “extinct in the wild” improved in status by three full categories out of six on its Red List of Threatened Species.

There are now an estimated 1,220 wild oryx across the Arabian Peninsula, in addition to between 6,000 and 7,000 in semi-captivity.

Experts at the IUCN have revealed to Arab News that the Arabian oryx could be upgraded to another level on its list within years, to “near-threatened,” thanks to regional breeding programs and reintroduction initiatives in the Kingdom, the UAE and the wider Gulf.

“About 40 years or so ago, the Arabian oryx was extinct in the wild formally, which meant there were none of these animals left in the wild, just those in captivity or in private collections,” said David Mallon, co-chair of the IUCN Species Survival Commission’s Antelope Specialist Group.

“Unfortunately, we don’t really have very much detailed information on the past. We’ve just got plenty of anecdotal reports of oryx around, and as far as we know the species was very widespread across the whole of the Arabian Peninsula. In the north it went as far as Iraq and Kuwait, Syria in the northwest and then Yemen, Saudi Arabia, Oman and the UAE in the south,” he added.

“But as soon as motor vehicles and modern weapons arrived, the destructive potential of hunting rapidly increased. Before, if you were on a camel and you had a single shot, by the time you had another bullet in the gun the oryx would’ve run off. But when motor vehicles and more modern, reloadable rifles were introduced — you can wear oryx out through exhaustion — hunting became a lot easier.”

Their numbers rapidly declined, and by 1950 the northern population had disappeared.

“This just left the southern population based around the Empty Quarter, southeast Saudi Arabia and the border of the UAE and Oman. Then by the 1960s, it went down and down and down,” Mallon said.

Oryx, which included the World Wildlife Fund and Phoenix Zoo in the US, was set up to establish a herd in captivity to prepare to reintroduce them into the wild.

“They caught a few of them from the southern population in Yemen on the border with Oman and took them back to London Zoo. Then there were a couple donated from the ruler of Saudi Arabia at the time, and they were taken to Phoenix Zoo in Arizona, which has a similar desert climate, and they built up this world herd,” Mallon said, adding that this provided hope for the desert animal.

The first reintroduction of 10 animals was in 1982 at the Omani Central Desert and Coastal Hills in the Arabian Oryx Sanctuary.

It was subsequently extended to Saudi Arabia at the Mahazat Al-Sayd Protected Area.

Releases in this fenced area began in 1990.

How the Arabian oryx was brought back from extinction
Credit: Arab News

In 1995, a secondary release site was established in Uruq Bani Ma’arid in the southern part of the Kingdom.

In 1997, said Mallon, oryx were released in three sites in northern Israel, and were introduced to the UAE a few years later in the oryx reserve in Abu Dhabi.

Other sites have since been established, and reintroductions in “semi-captive” sites — vast fenced areas to protect them from poachers — have also been made in Jordan and Bahrain, while reintroductions in Kuwait, Iraq and Syria have been proposed, according to the IUCN.

Successful population growth and releases, in addition to the estimated millions of dollars being spent across the Gulf annually on conservation, have driven the population numbers to current levels.

Mallon said it is a major feat to have brought the Arabian oryx back from the brink of extinction, and one that the IUCN hopes will be repeated for other threatened species.

“The Arabian oryx was ‘extinct’ on the Red List, then they became ‘critically endangered.’ Once the population increased they moved to ‘endangered,’ and then moved to a level where they could be called ‘vulnerable.’ It’s a really good conservation story. The next target they have to get to is ‘near-threatened,’ and that’s not far off,” he added.

The IUCN formally categorizes numbers of a species that are at reproductive age.

“We only count the mature individuals, so we don’t count the young ones. We have about 1,220 now, including the young ones, and we’d say about 850 are mature,” Mallon said.

“For the oryx to move to the ‘near-threatened’ category, we’d need to get figures to about 1,400 of these animals, so about half as many again. Considering where we were and where we are now, this is an achievable feat.”

The main populations of the species today are in Saudi Arabia, where there are about 600 in the wild, and the UAE, where there are more than 400 by official numbers, although Mallon said there may be significantly more.

Many more are in semi-captivity.

There are about 110 in the wild in Israel.

Despite a promising start in Oman, few of the species remain in the country due to poaching.

The IUCN estimates that there are just 10 left in the wild in Oman, with a couple of hundred more in semi-captivity.

Mallon said there are few conservation stories as successful as the Arabian oryx, and it was the foresight of Saudi and Emirati rulers, and bodies that established large breeding sites across the Arab world, that have saved the animal from extinction.

Coordination between the Gulf Cooperation Council (GCC) countries — such as the General Secretariat for the Conservation of the Arabian Oryx, which was established in 2001 as a landmark regional initiative aimed at coordinating and unifying conservation efforts in the Arabian Peninsula — has also helped.

“This helps to vary the genetics as much as possible, and ensures the longevity of the species,” said Mallon.

“There has been a huge amount of genetic sampling of all the herds to establish which ones are the most diverse. They’re genetically well-managed, and the animals are very carefully looked after.”

Conservation of endangered animals is a growing trend in the Kingdom. In the study “Conservation in Saudi Arabia: Moving from Strategy to Practice,” published in the Saudi Journal of Biological Sciences in 2018, authors noted that there are “marked conservation successes” in the Kingdom of not only the Arabian oryx, but two other endangered species: The sand gazelle and the Arabian gazelle.

The report added that the Saudi Wildlife Authority, established in 1986, has introduced several measures, with more on the way, to deter poachers and other factors that negatively affect populations of endangered species.

But Mallon said challenges for the Arabian oryx remain: “What’s needed is to continue with the captive breeding efforts to continue breeding animals, to continue the existing reintroduction sites and maintaining regional efforts and collaboration across the Arabian Peninsula. This is vital to maximize genetic diversity and reduce the risk of inbreeding.”

He added: “A massive Arabia Peninsula-wide education program on not shooting and hunting, and confiscation of weapons and a massive license system, would also help.”

Mallon said: “Without conservation, these species probably wouldn’t survive. Yet the Arabian oryx is an important part of Arabian biodiversity. It’s the one animal that’s adapted to hyper-arid deserts.”

He added: “It’s an exemplar to a species that has adapted to these conditions, which will be very useful in the future in terms of climate change. It also has its natural role, and serves as a flagship for the desert ecosystem, and also has huge cultural value. So it’s almost the duty of people to preserve it.”

Mallon said efforts thus far deserve worldwide commendation.

“It has been a huge conservation success story of its time. At the time, it was an absolute flagship project. It was a real exemplar of what can be done,” he added.

“A crucial part of conservation success stories is to have government support, funding and long-term commitment. That’s what we’ve seen in Saudi Arabia, the UAE and the wider GCC.”

Author: Jennifer Bell | Source: Arab News [January 12, 2019]



Unique rock-carved steam bath discovered at Mayan city of Nakum in Guatemala

A unique steam bath carved in rock was discovered by Jagiellonian University researchers conducting excavations in the ancient Mayan city of Nakum in Guatemala. The more than 2,500-year-old structure could have also been the site of religious rituals.

Unique rock-carved steam bath discovered at Mayan city of Nakum in Guatemala
Nakum bath during excavations [Credit: Jarosław Źrałka]

‘We have initially thought that we have found a tomb. But step-by-step, having revealed different elements of the structure, we came to a conclusion that what we discovered is most probably a steam bath’, says Wiesław Koszkul from the JU Institute of Archaeology, pointing out that in the Mayan culture steam bath have been used for ritual purposes in addition to their practical function,. Even today they are attended by pregnant women, which is supposed to help them in labour.

‘In Mayan beliefs, caves and baths have an almost identical status. This is where both gods and first humans were born and from where they entered the world. Such places are considered entrances to the underworld, inhabited by gods and ancestors. Caves and baths were also associated with fertility, as the source of life-giving water’, explains Dr Jarosław Źrałka from the JU Institute of Archaeology, who co-directs the excavations.

The bath consists of several basic elements. The archaeologists have initially discovered a tunnel bored in the rock, diverting the excess water. On both sides of the tunnel, there are stairs leading to a two-metre passage to the main part of the bath, which is a rectangular room lined with stone seats for the bathing people.

In front of the entrance the archaeologists found a large oval rock niche, which was long used as a fireplace, as evidenced by a thick layer of burnt material. It was established that the temperature in that place must have been very high, as the rock had broken up in several places. Most probably, large stones had been put next to the fireplace and heated up. When water was poured over the stones, it turned to steam, which filled the room. The excess water flew down the drainage tunnel onto the hillside.

Unique rock-carved steam bath discovered at Mayan city of Nakum in Guatemala
Nakum bath during excavations. A fireplace niche, probably used for heating up stones
[Credit: Jarosław Źrałka]

Although the lower part of the bath was carved in rock, it can’t be considered an artificial cave due to the lack of natural vault. It is believed that Mayas built the roof, which kept the steam inside the structure, from wood, stones and mortar.

In the drainage tunnel, the researchers have found not only a dark layer of ashes, but also fragments of ceramic vessels and obsidian tools, which might have been used during bathing rituals.

The bath probably functioned from circa 700 BC  to circa 300 BC, when it was completely filled in with lime mortar and rubble. According to Wiesław Koszkul, this could have been related to the dynastic change in Nakum, or other important changes in the social and religious life of Mayas.

The bath is located in the north part of the ancient city of Nakum, on its main north-south axis. It is surrounded by ruins of other buildings, including temples, pyramids and palaces. The archaeologists believe that the bath was used by members of the local elite, probably including priests, not only for hygiene, but also for religious purposes. In Mayan steam baths, the washing of the body was accompanied by the symbolic purification of the soul before major religious feasts.

Unique rock-carved steam bath discovered at Mayan city of Nakum in Guatemala
Visualisation of Nakum bath [Credit: Piotr Kołodziejczyk Junior/Proyecto Arqueologico Nakum]

Although similar baths are known to have been used in the Mayan culture during the recent millenniums, so far the researchers have only found small fragments of these structures from the ancient times. This is why the discovery of an almost perfectly preserved facility is considered so important.
The JU archaeologists have been exploring the ruins of the ancient city of Nakum for over a dozen years. So far, they have managed to reveal and study a number of structures, including graves, temples, palaces and residential buildings. Their most interesting finds comprise unique sacrificial items, such as nine clay heads representing Mayan gods, ceramic disks, and pendants made from human bone, a polychromic frieze with a mythological scene found under one of the buildings, and, most notably, an untouched royal tomb discovered in one of the pyramids in 2006. The grave goods included a jadeite pectoral with a hieroglyphic inscription.

Source: Jagiellonian University [January 12, 2019]




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