среда, 1 января 2020 г.

Anglo-Saxon ‘Dark Age’ House and Hall, Butser Ancient Farm, Hampshire, August 2019.

Anglo-Saxon ‘Dark Age’ House and Hall, Butser Ancient Farm, Hampshire, August 2019.

* This article was originally published here

Researchers make new discoveries set to reveal the geology of planets outside our solar system

Three OU astronomers today announced groundbreaking discoveries allowing scientists to understand planets outside the solar system. Professor Carole Haswell, Dr. Daniel Staab and Dr. John Barnes discovered three, new, nearby planetary systems.

Researchers make new discoveries set to reveal the geology of planets outside our solar system
Dispersed Matter Planet Project target selection area
[Credit: The Open University]
Research led by Professor Haswell found the exoplanets—planets outside the solar system—as part of the Dispersed Matter Planet Project (DMPP).

Dispersed Matter Planet Project

The project was funded by the UK Science and Technology Facilities Council and includes an international team of researchers. The project team used the High Accuracy Radial Velocity Planet Searcher (HARPS), a high-precision planet-finding spectrograph, on the European Southern Observatory's 3.6m telescope at La Silla in Chile, to detect the planetary systems.

The team studied stars known as DMPP-1, DMPP-2 and DMPP-3. The planets discovered, DMPP-1b, DMPP-1c, DMPP-1d, DMPP-1e, DMPP-2b and DMPP-3Ab, are very close to the stars and are heated to temperatures of 1100 degrees C–1800 degrees C. At these temperatures, the atmosphere and even the rocky surface of the planet can be lost, and some of this material disperses to form a thin shroud of gas.

Researchers make new discoveries set to reveal the geology of planets outside our solar system
Artist impression of DMPP-1 [Credit: The Open University]
This shroud filters the light from the star, producing clues that allowed the team to pick out the tiny fraction of stars with these unusual, very hot planets. With further study, the chemical composition of the shroud can be measured, revealing the type of rock on the surface of the hot planet.

Planets outside the solar system

The new planets, particularly DMPP-1d, DMPP-1e and DMPP-3Ab, could hold the key to unlocking the geology of the rocky planets outside the Earth's solar system.

Professor Carole Haswell, head of Astronomy at the Open University, said, "These new discoveries are very promising for further studies. They should allow us to measure the relationships between the mass, size and composition of planets outside our own solar system.

Researchers make new discoveries set to reveal the geology of planets outside our solar system
Artist impression of DMPP-2 [Credit: The Open University]
"We can now see how planets in general are built, and whether our own planet is typical. For example, we don't yet know if it is a coincidence that in the solar system, the Earth and Venus are the biggest rocky objects and have the largest fraction of their mass made of iron."

New discoveries explained

DMPP–1 has three hot super-Earth planets with masses between three and 10 times that of Earth, each orbiting the star every few days. It also has a warm Neptune-mass planet which orbits the star every 20 days.

Dr. Daniel Staab, a former Ph.D. student at the Open University, said: "DMPP–1 hosts a really important planetary system with three low mass exoplanets whose composition we can measure."

Researchers make new discoveries set to reveal the geology of planets outside our solar system
Artist impression of DMPP-3AB [Credit: The Open University]
DMPP–2b is a giant planet with a mass almost half that of Jupiter in a five-day orbit. It had been overlooked in previous studies because the star pulsates, which obscures the signature of the gravitational pull of the orbiting planet.

Commenting on the most exciting of these new discoveries, Dr. John Barnes, a Research Fellow at The Open University, said, "DMPP-3 was a huge surprise, we were looking for a tiny signal indicating an orbiting, low mass planet, but the first thing we found was a huge signal due to a companion star we hadn't expected."

The companion star, DMPP-3B, is only just massive enough to sustain hydrogen fusion, and is among the very lowest mass of all the stars powered by the same mechanism as the sun. These tiny stars are very dim and difficult to find. After accounting for this dim star, Dr. Barnes and the team found a planet, DMPP-3Ab, two or three times as massive as Earth, orbiting the brighter star every seven days. Dr. Barnes said, "It is hard to see how the planet got there."

Professor Haswell, Dr Staab, Dr Barnes and an international team have written papers on the three discoveries published in Nature Astronomy [paper 1, paper 2, paper 3].

Author: Bridgette Honegan | Source: The Open University [December 24, 2019]

* This article was originally published here

Back To Back Perseid Meteors with Audible Ping

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Channel: Frankie Lucena  

These meteors were found to be early Perseid meteors. The audio ping was obtained by using a 500 foot long telephone wire connected to my PC soundcard. This allows me to capture atmospheric sounds that are either VLF frequencies or ionization in the air. In this case, it picked up the ionization in the upper atmosphere caused by the meteors.

This event was captured in Puerto Rico on July 22, 2019 at 4:46am local time (08:46 UTC).

Video length: 0:10
Category: Science & Technology

Dod Law Prehistoric Rock Art Panels, Scottish Borders, 29.12.19.

Dod Law Prehistoric Rock Art Panels, Scottish Borders, 29.12.19.

* This article was originally published here

Evolution: Revelatory relationship

A new study of the ecology of an enigmatic group of novel unicellular organisms by scientists from Ludwig-Maximilians-Universitaet (LMU) in Munich supports the idea hydrogen played an important role in the evolution of Eukaryota, the first nucleated cells.

Evolution: Revelatory relationship
A hydrothermal vent in Loki’s Forest, deep beneath the North Atlantic [Credit: R.B. Pedersen,
Centre for Geobiology, University of Bergen]
One of the most consequential developments in the history of biological evolution occurred approximately 2 billion years ago with the appearance of the first eukaryotes - unicellular organisms that contain a distinct nucleus. This first eukaryotic lineage would subsequently give rise to all higher organisms including plants and animals, but its origins remain obscure.

Some years ago, microbiologists analyzed DNA sequences from marine sediments, which shed new light on the problem. These sediments were recovered from a hydrothermal vent at a site known as Loki's Castle (named for the Norse god of fire) on the Mid-Atlantic Ridge in the Arctic Ocean. Sequencing of the DNA molecules they contained revealed that they were derived from a previously unknown group of microorganisms.

Although the cells from which the DNA originated could not be isolated and characterized directly, the sequence data showed them to be closely related to the Archaea. The researchers therefore named the new group Lokiarchaeota.

Archaea, together with the phylum Bacteria, are the oldest known lineages of single-celled organisms. Strikingly, the genomes of the Lokiarchaeota indicated that they might exhibit structural and biochemical features that are otherwise specific to eukaryotes. This suggests that the Lokiarchaeota might be related to the last common ancestor of eukaryotes. Indeed, phylogenomic analysis of the Lokiarchaeota DNA from Loki's Castle strongly suggested that they were derived from descendants of one of the last common ancestors of Eukaryota and Archaea.

Professor William Orsi of the Department of Earth and Environmental Sciences at LMU, in cooperation with scientists at Oldenburg University and the Max Planck Institute for Marine Microbiology, has now been able to examine the activity and metabolism of the Lokiarchaeota directly. The results support the suggested relationship between Lokiarchaeota and eukaryotes, and provide hints as to the nature of the environment in which the first eukaryotes evolved. The new findings appear in the journal Nature Microbiology.

The most likely scenario for the emergence of eukaryotes is that they arose from a symbiosis in which the host was an archaeal cell and the symbiont was a bacterium. According to this theory, the bacterial symbiont subsequently gave rise to the mitochondria - the intracellular organelles that are responsible for energy production in eukaryotic cells. One hypothesis proposes that the archaeal host was dependent on hydrogen for its metabolism, and that the precursor of the mitochondria produced it.

This "hydrogen hypothesis" posits that the two partner cells presumably lived in an anoxic environment that was rich in hydrogen, and if they were separated from the hydrogen source they would have become more dependent on one another for survival potentially leading to an endosymbiotic event. "If the Lokiarchaeota, as the descendants of this putative ur-archaeon, are also dependent on hydrogen, this would support the hydrogen hypothesis," says Orsi. "However, up to now, the ecology of these Archaea in their natural habitat was a matter of speculation."

Orsi and his team have now, for the first time, characterized the cellular metabolism of Lokiarchaeota recovered from sediment cores obtained from the seabottom in an extensive oxygen-depleted region off the coast of Namibia. They did so by analyzing the RNA present in these samples. RNA molecules are copied from the genomic DNA, and serve as blueprints for the synthesis of proteins. Their sequences therefore reflect patterns and levels of gene activity. The sequence analyses revealed that Lokiarchaeota in these samples outnumbered bacteria by 100- to 1000-fold. "That strongly indicates that these sediments are a favorable habitat for them, promoting their activity," says Orsi.

He and his colleagues were able to establish enrichment cultures from the Lokiarchaeota in the sediment samples in the laboratory. This enabled them to study the metabolism of these cells using stable carbon isotopes as markers. The results demonstrated that the microorganisms make use of a complex network of metabolic pathways. Moreover, the data confirmed that Lokiarchaea indeed use hydrogen for the fixation of carbon dioxide. This process enhances the efficiency of metabolism, and allows these species to maintain high levels of biochemical activity, in spite of the energy limited conditions of their anoxic natural habitat.

"Our experimental evidence the hydrogen hypothesis for the first eukaryotic cell," says Orsi. "Consequently, the earliest eukaryotes could have originated in oxygen-depleted and hydrogen-rich marine sediments, such as those in which modern Lokiarchaeota are particularly active today."

Source: Ludwig Maximilian University of Munich [December 27, 2019]

* This article was originally published here

Something Slithers out of a moving cars trunk then a redneck stabs a tire!

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Channel: Terry's Theories  

I don't know how to describe it other than some kind of thing either falling or slithering out of a trunk of a moving car onto the street and then takes off.

Video length: 1:44
Category: Science & Technology

Duddo Stone Circle, Scottish Borders, 29.12.19.

Duddo Stone Circle, Scottish Borders, 29.12.19.

* This article was originally published here

A 'pivotal' moment for understanding whale evolution

Scientists could soon better investigate the feeding behaviours of extinct dolphin and whale species. A third year student at Japan's Nagoya University has found that the range of motion offered by the joint between the head and neck in modern-day cetaceans, a group of marine mammals that also includes porpoises, accurately reflects how they feed. The authors of the study, published in the Journal of Anatomy, suggest this method could help overcome current limitations in extrapolating the feeding behaviours of extinct cetaceans.

A 'pivotal' moment for understanding whale evolution
The most dorsi-flexed [θdors(°)] and ventro-flexed [θvent(°)] atlanto-occipital joint angles of minke whale
(Balaenoptera acutorostrata) and beluga (Delphinapterus leucas). The range of atlanto-occipital
 joint angle (ROM) varies by taxa [Credit: Nagoya University]
Taro Okamura of Nagoya University and Shin-ichi Fujiwara of the Nagoya University Museum examined the skulls and cervical skeletons of 56 cetaceans that are still in existence, representing 30 different species. They assessed the range of motion of the 'atlanto-occipital joint' in each skeleton, a joint that forms between the base of the skull and the first cervical vertebra. They then categorized each cetacean according to their well-studied feeding behaviours, including how they approach their prey, move it within their oral cavities, and swallow it.

"We found that the range of neck-head flexibility strongly reflects the difference of feeding strategies among whales and dolphins," says Okamura. "This index can be easily applied to reconstruct the feeding strategies of extinct whales and dolphins," he adds.

Cetaceans are known for their diverse behaviors, physiologies, ecologies and diets. Some cetaceans feed on organisms in the open water, while others feed on those found near the ocean floor. Some whales are ram feeders, widely opening their mouths to gather zooplankton and other actively swimming organisms into their mouths while moving forward. Other whales, like the sperm whale, suction their prey into their oral cavities. The orca whale and some dolphins bite the fish they catch into smaller segments, a process that may require head movement. Other dolphins swallow their prey whole.

A 'pivotal' moment for understanding whale evolution
The range of atlanto-occipital joint angle (ROM) depends on the prey habitat, and the way cetaceans use
to capture prey. The cetaceans that prefer benthic/demersal prey had a relatively large ROM compared
with the ones that prefer pelagic prey. The ROM was relatively large in raptorial feeders, followed by
suction- and ram-filter feeders, in ascending order. Among raptorial feeders, the ROM was larger
in taxa that facultatively tear off the fresh of prey than the ROM in taxa that swallow
the prey without processing [Credit: Nagoya University]
Until now, scientists have used the structures of teeth, throat bones and lower jaws in cetacean fossils to develop an idea of what their feeding behaviours might have looked like. But these individual features can't accurately predict the behaviors of extinct cetaceans. For example, the teeth of some suction feeders, like those of the sperm whale, aren't suggestive of this kind of feeding. Okamura and Fujiwara propose that using a combination of features, which include the range of motion of the atlanto-occipital joint, could help to develop more accurate descriptions of extinct cetacean feeding behaviours.

In prehistoric times, many different types of cetaceans existed, including ones with walrus-like tusks, extremely long snouts, and an ancient sperm whale with huge predatory teeth. The ancient baleen whale had teeth, whereas modern-day baleen whales have 'baleen,' or fringed plates, in their place. This has created much interest in how baleen whale feeding, for example, has evolved from catching prey with teeth to filtering it with baleen.

The two researchers next plan to determine the atlanto-occipital joint range of motion in some of these cetacean fossils to attempt to develop reconstructions of how they used to feed. Answering these questions could help reveal the evolutionary process of the diverse feeding behaviours among cetaceans.

Source: Nagoya University [December 27, 2019]

* This article was originally published here

Early Morning Fireball over Puerto Rico

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Channel: Frankie Lucena  

According to the star map, this could be a Southern Delta Aquarid meteor. I've captured many meteors at dawn but never a fireball. This one appeared just as the Sun was beginning to rise in the east at 5:35am local time (09:35 UTC).

Video length: 0:09
Category: Science & Technology

ancientpeopleancientplaces:‘Liminal’ PoemWritten by The Silicon Tribesman. All Rights...


‘Liminal’ Poem

Written by The Silicon Tribesman. All Rights Reserved, 2020.

* This article was originally published here

Forces from Earth's spin may spark earthquakes and volcanic eruptions at Mount Etna

New research suggests forces pulling on Earth's surface as the planet spins may trigger earthquakes and eruptions at volcanoes.

Forces from Earth's spin may spark earthquakes and volcanic eruptions at Mount Etna
An image of an eruption at Mount Etna on October 30, 2002 from the International Space Station. The eruption,
triggered by a series of earthquakes, was one of the most vigorous in years. Ashfall was reported in Libya,
 more than 350 miles away [Credit: NASA]
Seismic activity and bursts of magma near Italy's Mount Etna increased when Earth's rotational axis was furthest from its geographic axis, according to a new study comparing changes in Earth's rotation to activity at the well-known Italian volcano.

Earth's spin doesn't always line up perfectly with its north and south poles. Instead, the geographic poles often twirl like a top around Earth's rotational axis when viewed from space. Every 6.4 years, the axes line up and the wobble fades for a short time—until the geographic poles move away from the spin axis and begin to spiral once again.

This phenomenon, called polar motion, is driven by changes in climate due to things like changing seasons, melting ice sheets or movement from tectonic plates. As polar motion fluctuates, forces pulling the planet away from the sun tug at Earth's crust, much like tides due to the gravitational pull from the sun and moon. The tide from polar motion causes the crust to deform over the span of seasons or years. This distortion is strongest at 45 degrees latitude, where the crust moves by about 1 centimeter (0.4 inches) per year.

Now, a new study published in AGU's journal Geophysical Research Letters suggests that polar motion and subsequent shifts in Earth's crust may increase volcanic activity.

"I find it quite exciting to know that while climate drives Earth's spin, its rotation can also drive volcanoes and seismicity," said Sebastien Lambert, a geophysicist at Paris Observatory in France and lead author of the study.

The new findings, however, don't allow scientists to forecast volcanic activity. Although the study suggests earthquakes might be more common or volcanic eruptions may eject more lava when the distance between Earth's geographic and rotational axes is at its peak, the timescale is too large for meaningful short-term forecasts, according to the authors.

But the results point to an interesting concept. "It's the first time we've found this relationship in this direction from Earth's rotation to volcanoes," Lambert said. "It's a small excitation process, but if you accumulate a small excitation over a long time it can lead to measurable consequences."

Shaking Earth

Previous work has shown the length of a day on Earth, which changes based on the speed of Earth's spin, also deforms the crust and could affect volcanic behavior. In the new study, Lambert and his colleague, Gianluca Sottili, a volcanologist from Sapienza University of Rome in Italy, wanted to study the relationship between polar motion and volcanic activity.

Polar motion describes the motion of the Earth’s spin axis (shown in orange) with respect to the geographic north 
and south poles (shown in blue). Over time, the geographic poles appear to spin away from the spin axis when 
viewed from space and then back again. Viewed from the perspective of someone on Earth, the spin axis instead 
appears to spiral away from the geographic poles and then spiral back. The motion of the spin pole with 
respect to the geographic poles fixed to the Earth’s crust is called polar motion. Note: The size and speed 
of the spiral are greatly exaggerated for clarity [Credit: NASA/GSFC Science Visualization Studio]

They focused on Mount Etna because the volcano is well-studied, meaning there's plenty of data, and it sits just south of 45 degrees latitude. There also weren't any volcanic crises out of the ordinary at Mount Etna during the study period, which might otherwise mask the signal from polar motion.

Lambert and Sottili used seismic records from 11,263 earthquakes that happened within 43 kilometers (26.7 miles) of Mount Etna's summit between 1999 and 2019. The team also used records of how much magma erupted from the volcano since 1900. They included 62 eruptions in the analysis, based on the time span between events.

The pair then compared the distance between the geographic and rotational poles at the time each event occurred to determine whether volcanic activity was connected to Earth's rotation.

Lambert and Sottili discovered there were more earthquakes when Earth's rotational pole was furthest from the geographic axis—at the point in Earth's top-like spin when it looks like it is about to fall over. Between 1999 and 2019, those peaks were in 2002 and 2009. An expected peak in 2015 never materialized because one of the oscillations contributing to polar motion has been slowing down.

The team also uncovered a link between the amount of magma ejected during an eruption. Polar motion appears to drive the largest eruptions from Mount Etna, although to a lesser extent than its seismic activity, according to the researchers.

Examining volcanoes in the Ring of Fire to see if Earth's spin impacts their activity would surely be interesting, Sottili said, who was senior author of the study. Even expanding to other planets might open scientists' view of how external forces impact volcanoes on the surface, he added.

Author: Erin I. Garcia De Jesus | Source: American Geophysical Union [December 27, 2019]

* This article was originally published here

Gigantic Jets over The Caribbean Just South of Puerto Rico

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Channel: Frankie Lucena  

These Gigantic Jets were recorded on Aug 6 2019 at 08:23:24 and 08:23:52 UTC, so they were just 28 seconds apart. I used a watec 902H Ultimate camera with a 12mm lens at F/1.2.

Video length: 0:31
Category: Science & Technology

2020 January 1 Betelgeuse Imagined Illustration Credit: ESO, L....

2020 January 1

Betelgeuse Imagined
Illustration Credit: ESO, L. Calcada

Explanation: Why is Betelgeuse fading? No one knows. Betelgeuse, one of the brightest and most recognized stars in the night sky, is only half as bright as it used to be only five months ago. Such variability is likely just normal behavior for this famously variable supergiant, but the recent dimming has rekindled discussion on how long it may be before Betelgeuse does go supernova. Known for its red color, Betelgeuse is one of the few stars to be resolved by modern telescopes, although only barely. The featured artist’s illustration imagines how Betelgeuse might look up close. Betelgeuse is thought to have a complex and tumultuous surface that frequently throws impressive flares. Were it to replace the Sun (not recommended), its surface would extend out near the orbit of Jupiter, while gas plumes would bubble out past Neptune. Since Betelgeuse is about 700 light years away, its eventual supernova will not endanger life on Earth even though its brightness may rival that of a full Moon. Astronomers – both amateur and professional – will surely continue to monitor Betelgeuse as this new decade unfolds.

∞ Source: apod.nasa.gov/apod/ap200101.html

* This article was originally published here

North Atlantic Current may cease temporarily in the next century

The North Atlantic Current transports warm water from the Gulf of Mexico towards Europe, providing much of north-western Europe with a relatively mild climate. However, scientists suspect that meltwater from Greenland and excessive rainfall could interfere with this ocean current. Simulations by scientists from the University of Groningen and Utrecht University showed that it is unlikely that the current will come to a complete stop, due to small and rapid changes in precipitation over the North Atlantic. However, there is a 15 percent likelihood that there will be a temporary change in the current in the next 100 years. The results were published in the journal Scientific Reports.

North Atlantic Current may cease temporarily in the next century
This image shows the Atlantic Ocean Circulation, which transports relatively warm water
from the Gulf of Mexico to north-western Europe [Credit: Sven Baars,
University of Groningen]
'The oceans store an immense amount of energy and the ocean currents have a strong effect on the Earth's climate,' says University of Groningen Associate Professor in Numerical Mathematics, Fred Wubs. Together with his colleague Henk Dijkstra from Utrecht University, he has studied ocean currents for some 20 years.

Box model

Ocean scientists have found that the Atlantic Ocean currents are sensitive to the amount of fresh water at the surface. Since the run-off of meltwater from Greenland has increased due to climate change, as has rainfall over the ocean, it has been suggested that this may slow down or even reverse the North Atlantic Current, blocking the transport of heat to Europe.

Simulations of the effects of freshwater on the currents have already been performed for some decades. 'Both high-resolution models, based on the equations describing fluid flows, and highly simplified box models have been used,' explains Wubs. 'Our colleagues in Utrecht created a box model that describes present-day large-scale processes in the ocean rather well.'

Total collapse

The idea was to use this box model to estimate the likelihood of small fluctuations in freshwater input causing a temporary slowing down or a total collapse of the North Atlantic Current. The current shows non-linear behaviour, which means that small changes can have large effects. The evolution of the physics described by the box model can only be obtained using simulations. 'As the transitions we were looking for are expected to be rare events, you need a huge number of simulations to estimate the chance of them happening,' says Wubs. However, the Dutch scientists found that a French scientist had devised a method to select the most promising simulations, reducing the number of full simulations required.

Sven Baars, a PhD student of Wubs, implemented this method efficiently and linked it to the Utrecht box model. Daniele Castellana, a PhD student of Dijkstra, performed the simulations. 'These simulations showed that the chances of a total collapse of the North Atlantic Current within the next thousand years are negligible,' says Wubs.


A temporary interruption in the delivery of relatively warm water to north-western Europe is more likely: 'In our simulations, the chances of this happening in the next 100 years are 15 percent.' Such temporary transitions may cause cold spells in the North Atlantic, although this needs to be verified in further studies. Therefore, the current study is just a first step in determining the risk. The model does not take into account considerable changes in freshwater in the North Atlantic, which can be caused by the melting of the ice sheets. Wubs: 'Confirming our results through simulation with a high-resolution climate model will be the next challenge.'

Source: University of Groningen [December 30, 2019]

* This article was originally published here

Elve Lightning over the Caribbean

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Channel: Frankie Lucena  

This Elve lightning event occurred just south of the Dominican Republic on Aug 20, 2019.

Video length: 0:09
Category: Science & Technology

How fish fins evolved just before the transition to land

Research on fossilized fish from the late Devonian period, roughly 375 million years ago, details the evolution of fins as they began to transition into limbs fit for walking on land.

How fish fins evolved just before the transition to land
Tom Stewart holds a fossil cast of a fin from a juvenile Sauripterus taylori, a late Devonian fish
with primitive features of tetrapods [Credit: Matt Wood]
The new study by paleontologists from the University of Chicago, published this week in the Proceedings of the National Academy of Sciences, uses CT scanning to examine the shape and structure of fin rays while still encased in surrounding rock. The imaging tools allowed the researchers to construct digital 3D models of the entire fin of the fishapod Tiktaalik roseae and its relatives in the fossil record for the first time. They could then use these models to infer how the fins worked and changed as they evolved into limbs.

Much of the research on fins during this key transitional stage focuses on the large, distinct bones and pieces of cartilage that correspond to those of our upper arm, forearm, wrist, and digits. Known as the "endoskeleton," researchers trace how these bones changed to become recognizable arms, legs and fingers in tetrapods, or four-legged creatures.

The delicate rays and spines of a fish's fins form a second, no less important "dermal" skeleton, which was also undergoing evolutionary changes in this period. These pieces are often overlooked because they can fall apart when the animals are fossilized or because they are removed intentionally by fossil preparators to reveal the larger bones of the endoskeleton. Dermal rays form most of the surface area of many fish fins but were completely lost in the earliest creatures with limbs.

"We're trying to understand the general trends and evolution of the dermal skeleton before all those other changes happened and fully-fledged limbs evolved," said Thomas Stewart, PhD, a postdoctoral researcher who led the new study. "If you want to understand how animals were evolving to use their fins in this part of history, this is an important data set."

How fish fins evolved just before the transition to land
A CT scan of Tiktaalik's fin skeleton, showing its dorsal rays (yellow)
and ventral rays (cyan) [Credit: Tom Stewart]
Stewart and his colleagues worked with three late Devonian fishes with primitive features of tetrapods: Sauripterus taylori, Eusthenopteron foordi and Tiktaalik roseae, which was discovered in 2006 by a team led by UChicago paleontologist Neil Shubin, PhD, the senior author of the new study. Sauripterus and Eusthenopteron were believed to have been fully aquatic and used their pectoral fins for swimming, although they may have been able to prop themselves up on the bottom of lakes and streams. Tiktaalik may have been able to support most of its weight with its fins and perhaps even used them to venture out of the water for short trips across shallows and mudflats.

"By seeing the entire fin of Tiktaalik we gain a clearer picture of how it propped itself up and moved about. The fin had a kind of palm that could lie flush against the muddy bottoms of rivers and streams," Shubin said.

Stewart and Shubin worked with undergraduate student Ihna Yoo and Justin Lemberg, PhD, another researcher in Shubin's lab, to scan specimens of these fossils while they were still encased in rock. Using imaging software, they then reconstructed 3D models that allowed them to move, rotate and visualize the dermal skeleton as if it were completely extracted from the surrounding material.

The models showed that the fin rays of these animals were simplified, and the overall size of the fin web was smaller than that of their fishier predecessors. Surprisingly, they also saw that the top and bottom of the fins were becoming asymmetric. Fin rays are actually formed by pairs of bones. In Eusthenopteron, for example, the dorsal, or top, fin ray was slightly larger and longer than the ventral, or bottom one. Tiktaalik's dorsal rays were several times larger than its ventral rays, suggesting that it had muscles that extended on the underside of its fins, like the fleshy base of the palm, to help support its weight.

How fish fins evolved just before the transition to land
Tiktaalik roseae, a 375-million-year-old 'fishapod' has features of both fish and four-legged tetrapods.
In a new study, Tom Stewart and Neil Shubin analyzed the structure of Tiktaalik's fins
just before the transition to land [Credit: Flick Ford]

"This provides further information that allows us to understand how an animal like Tiktaalik was using its fins in this transition," Stewart said. "Animals went from swimming freely and using their fins to control the flow of water around them, to becoming adapted to pushing off against the surface at the bottom of the water."

Stewart and his colleagues also compared the dermal skeletons of living fish like sturgeon and lungfish to understand the patterns they were seeing in the fossils. They saw some of the same asymmetrical differences between the top and bottom of the fins, suggesting that those changes played a larger role in the evolution of fishes.

"That gives us more confidence and another data set to say these patterns are real, widespread and important for fishes, not just in the fossil record as it relates to the fin-to-limb transition, but the function of fins broadly."

Source: University of Chicago Medical Center [December 30, 2019]

* This article was originally published here

Ringed Shaped Object Seen From The Earth To The Moon To The Sun.

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Channel: Terry's Theories  

Here Is Some Evidence That I have Put Together Of These Ringed Shaped Or Doughnut Shaped UFOs Are Something Other Than Dust Particles On A Lens.These Objects Have Been Seen During The NASA Tether Incident. I Have Also Found Them Close To The SUN With The Helioviewer. I Have Found A Few Videos Showing These Ringed Or Doughnut Shaped UFOs As Well. A Big Thanks To Tom Brown For Letting Me Use His Video Labeled
Doughnut-Shaped UFO Floats by ISS. If you can donate please do https://www.paypal.com/paypalme2/Franklin1275?locale.x=en_US thank you.
Helioviewer :https://helioviewer.org/
Tom Browns : Doughnut-Shaped UFO Floats by ISS https://www.youtube.com/watch?v=fvoqtEF2o_s
Jason Callum, MoonCat72 :https://www.youtube.com/watch?v=a1Wjxyr1dWA

Video length: 4:18
Category: Science & Technology

The growing Tibetan Plateau shaped the modern biodiversity

Holding particular biological resources, the Tibetan Plateau is a unique geologic-geographic-biotic interactively unite and hence plays an important role in the global biodiversity domain. The Tibetan Plateau has undergone vigorous environmental changes since the Cenozoic, and played roles as switching from "a paradise of tropical animals and plants" to "the cradle of Ice Age mammalian fauna".

The growing Tibetan Plateau shaped the modern biodiversity
Local origination of endemism of fishes and mammals in the Tibetan Plateau
[Credit: Science China Press]
Recent significant paleontological discoveries have refined a big picture of the evolutionary history of biodiversity on that plateau against the backdrop of major environmental changes, and paved the way for the assessment of its far-reaching impact upon the biota around the plateau and even in more remote regions. Based on the newly reported fossils from the Tibetan Plateau which include diverse animals and plants, this paper presented general viewpoints of the biodiversity history on the Tibetan Plateau and its influence in a global scale.

This paper defined the Tibetan Plateau as an evolutionary junction of the history of modern biodiversity, whose performance can be categorized in the following three patterns: (1) Local origination of endemism; (2) Local origination and "Out of Tibet"; (3) Intercontinental dispersal via Tibet.

The growing Tibetan Plateau shaped the modern biodiversity
Local origination and "Out of Tibet" of mammals in the Tibetan Plateau
[Credit: Science China Press]
The first pattern is exemplified by the snow carps (schizothoracine fishes), the major component of the freshwater fish fauna on the plateau, whose temporal distribution pattern of the fossil schizothoracines approximately mirrors the spatial distribution pattern of their living counterparts. Through ascent with modification, their history reflects the biological responses to the stepwise uplift of the Tibetan Plateau.

The second pattern is represented by the dispersal history of some mammals since the Pliocene and some plants. The ancestors of some Ice Age mammals, e.g., the wholly rhino, Arctic fox, and argali sheep first originated and evolved in the uplifted and frozen Tibet during the Pliocene, and then migrated toward the Arctic regions or even the North American continent at beginning of the Ice Age; the ancestor of pantherines (big cats) first rose in Tibetan Plateau during the Pliocene, followed by the disperse of its descendants to other parts of Asia, Africa, North and South America to play as top predators of the local ecosystems. The early members of some plants, e.g., Elaeagnaceae appeared in Tibet during the Late Eocene and then dispersed and widely distributed to other regions.

The growing Tibetan Plateau shaped the modern biodiversity
Intercontinental dispersals via Tibet, taking Ailanthus and climbing perches as examples
[Credit: Science China Press]

The last pattern is typified by the history of the tree of heaven (Ailanthus) and climbing perch. Ailanthus originated in the Indian subcontinent, then colonized into Tibet after the Indian-Asian plate collision, and dispersed from the Tibetan Plateau to East Asia, Europe and even North America. The climbing perches among freshwater fishes probably rose in Southeast Asia during the Middle Eocene, dispersed to Tibet and then migrated into Africa via the docked India. These cases highlight the role of Tibet, which was involved in the continental collision, in the intercontinental biotic interchanges. The three evolutionary patterns above reflect both the history of biodiversity on the plateau as well as the biological and environmental effects of tectonic uplift.

Since the initiation of the Second Tibetan Plateau Scientific Expedition in 2017, this review is the first comprehensive conclusions on the relationship between the uplift of the Tibetan Plateau and the evolution of biota based on latest numerous fossil records. It provides important scientific evidence for the influence of the uplift of the Tibetan Plateau on the environment and biota.

The findings are published in Science China Earth Sciences.

Source: Science China Press [December 30, 2019]

* This article was originally published here

Dark Object Does A Death Dive Towards The Ground After A Lightning Strike!

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Channel: Terry's Theories  

Megan Taylor From Somerset England Records A Thunderstorm Inadvertently Catches A Mysterious Dark Object Speeding To Earth After A Lightning Strike.Hey guys if you are able to donate a dollar or two it would be a great help to me to grow the channel, moneys will go toward computer equipment to better the cause.https://www.paypal.com/paypalme2/Franklin1275?locale.x=en_US

Video length: 1:42
Category: Science & Technology

Life could have emerged from lakes with high phosphorus

Life as we know it requires phosphorus. It's one of the six main chemical elements of life, it forms the backbone of DNA and RNA molecules, acts as the main currency for energy in all cells and anchors the lipids that separate cells from their surrounding environment. But how did a lifeless environment on the early Earth supply this key ingredient?

Life could have emerged from lakes with high phosphorus
Eastern California's Mono Lake has no outflow, allowing salts to build up over time. The high salts
in this carbonate-rich lake can grow into pillars [Credit: Matthew Dillon/Flickr]
"For 50 years, what's called 'the phosphate problem,' has plagued studies on the origin of life," said first author Jonathan Toner, a University of Washington research assistant professor of Earth and space sciences.

The problem is that chemical reactions that make the building blocks of living things need a lot of phosphorus, but phosphorus is scarce. A new UW study, published in the Proceedings of the National Academy of Sciences, finds an answer to this problem in certain types of lakes.

The study focuses on carbonate-rich lakes, which form in dry environments within depressions that funnel water draining from the surrounding landscape. Because of high evaporation rates, the lake waters concentrate into salty and alkaline, or high-pH, solutions. Such lakes, also known as alkaline or soda lakes, are found on all seven continents.

The researchers first looked at phosphorus measurements in existing carbonate-rich lakes, including Mono Lake in California, Lake Magadi in Kenya and Lonar Lake in India.

While the exact concentration depends on where the samples were taken and during what season, the researchers found that carbonate-rich lakes have up to 50,000 times phosphorus levels found in seawater, rivers and other types of lakes. Such high concentrations point to the existence of some common, natural mechanism that accumulates phosphorus in these lakes.

Life could have emerged from lakes with high phosphorus
This 2007 photo shows Lake Magadi in Kenya, a carbonate-rich lake whose bed is made of volcanic
rock. The lake's salty water is rich in microbes and it attracts other life, including these
flamingoes and zebras [Credit: Stig Nygaard/Flickr]
Today these carbonate-rich lakes are biologically rich and support life ranging from microbes to Lake Magadi's famous flocks of flamingoes. These living things affect the lake chemistry. So researchers did lab experiments with bottles of carbonate-rich water at different chemical compositions to understand how the lakes accumulate phosphorus, and how high phosphorus concentrations could get in a lifeless environment.

The reason these waters have high phosphorus is their carbonate content. In most lakes, calcium, which is much more abundant on Earth, binds to phosphorus to make solid calcium phosphate minerals, which life can't access. But in carbonate-rich waters, the carbonate outcompetes phosphate to bind with calcium, leaving some of the phosphate unattached. Lab tests that combined ingredients at different concentrations show that calcium binds to carbonate and leaves the phosphate freely available in the water.

"It's a straightforward idea, which is its appeal," Toner said. "It solves the phosphate problem in an elegant and plausible way."

Phosphate levels could climb even higher, to a million times levels in seawater, when lake waters evaporate during dry seasons, along shorelines, or in pools separated from the main body of the lake.

"The extremely high phosphate levels in these lakes and ponds would have driven reactions that put phosphorus into the molecular building blocks of RNA, proteins, and fats, all of which were needed to get life going," said co-author David Catling, a UW professor of Earth & space sciences.

Life could have emerged from lakes with high phosphorus
Coloured dots show the level of phosphorus measured in different carbonate-rich lakes around the world.
Existing carbonate-rich lakes can contain up to 50,000 times the levels of phosphate found in seawater,
with the highest levels measured in British Columbia's Goodenough and Last Chance
lake system (yellow dots) [Credit: Toner et al., 2019]

The carbon dioxide-rich air on the early Earth, some four billion years ago, would have been ideal for creating such lakes and allowing them to reach maximum levels of phosphorus. Carbonate-rich lakes tend to form in atmospheres with high carbon dioxide. Plus, carbon dioxide dissolves in water to create acid conditions that efficiently release phosphorus from rocks.

"The early Earth was a volcanically active place, so you would have had lots of fresh volcanic rock reacting with carbon dioxide and supplying carbonate and phosphorus to lakes," Toner said. "The early Earth could have hosted many carbonate-rich lakes, which would have had high enough phosphorus concentrations to get life started."

Another recent study by the two authors showed that these types of lakes can also provide abundant cyanide to support the formation of amino acids and nucleotides, the building blocks of proteins, DNA and RNA. Before then researchers had struggled to find a natural environment with enough cyanide to support an origin of life. Cyanide is poisonous to humans, but not to primitive microbes, and is critical for the kind of chemistry that readily makes the building blocks of life.

Author: Hannah Hickey | Source: University of Washington [December 30, 2019]

* This article was originally published here

Lucky Shot : Meteor Appears During Jupiter Time-Lapse Video

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Channel: Frankie Lucena  

I was testing a Sony CCTV camera by doing a video time-lapse of Jupiter when all of a sudden a meteor appeared. I didn't expect to be able to also record the Galilean Moons. Ganymede and Callisto are located below Jupiter and IO was so close to Jupiter that it was hidden behind the glare. Europa shows up above Jupiter minutes later towards the bottom of the screen.

Video length: 0:23
Category: Science & Technology


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