Computer simulations conducted by astrophysicists at Tohoku University in Japan, have revealed a new theory for the origin of supermassive black holes. In this theory, the precursors of supermassive black holes grow by swallowing up not only interstellar gas, but also smaller stars as well. This helps to explain the large number of supermassive black holes observed today.
Almost every galaxy in the modern Universe has a supermassive black hole at its center. Their masses can sometimes reach up to 10 billion times the mass of the Sun. However, their origin is still one of the great mysteries of astronomy. A popular theory is the direct collapse model where primordial clouds of interstellar gas collapse under self-gravity to form supermassive stars which then evolve into supermassive black holes. But previous studies have shown that direct collapse only works with pristine gas consisting of only hydrogen and helium. Heavier elements such as carbon and oxygen change the gas dynamics, causing the collapsing gas to fragment into many smaller clouds which form small stars of their own, rather than a few supermassive stars. Direct collapse from pristine gas alone can't explain the large number of supermassive blackholes seen today.
Sunmyon Chon, a postdoctoral fellow at the Japan Society for the Promotion of Science and Tohoku University and his team used the National Astronomical Observatory of Japan's supercomputer "ATERUI II" to perform long-term 3D high-resolution simulations to test the possibility that supermassive stars could form even in heavy-element-enriched gas. Star formation in gas clouds including heavy elements has been difficult to simulate because of the computational cost of simulating the violent splitting of the gas, but advances in computing power, specifically the high calculation speed of "ATERUI II" commissioned in 2018, allowed the team to overcome this challenge. These new simulations make it possible to study the formation of stars from gas clouds in more detail.
Contrary to previous predictions, the research team found that supermassive stars can still form from heavy-element enriched gas clouds. As expected, the gas cloud breaks up violently and many smaller stars form. However, there is a strong gas flow towards the center of the cloud; the smaller stars are dragged by this flow and are swallowed-up by the massive stars in the center. The simulations resulted in the formation of a massive star 10,000 time more massive than the Sun. "This is the first time that we have shown the formation of such a large black hole precursor in clouds enriched in heavy-elements. We believe that the giant star thus formed will continue to grow and evolve into a giant black hole," says Chon.
Read more at Science Daily
Jun 2, 2020
From dark to light in a flash: Smart film lets windows switch autonomously
Researchers have developed a new easy-to-use smart optical film technology that allows smart window devices to autonomously switch between transparent and opaque states in response to the surrounding light conditions.
The proposed 3D hybrid nanocomposite film with a highly periodic network structure has empirically demonstrated its high speed and performance, enabling the smart window to quantify and self-regulate its high-contrast optical transmittance. As a proof of concept, a mobile-app-enabled smart window device for Internet of Things (IoT) applications has been realized using the proposed smart optical film with successful expansion to the 3-by-3-inch scale. This energy-efficient and cost-effective technology holds great promise for future use in various applications that require active optical transmission modulation.
Flexible optical transmission modulation technologies for smart applications including privacy-protection windows, zero-energy buildings, and beam projection screens have been in the spotlight in recent years. Conventional technologies that used external stimuli such as electricity, heat, or light to modulate optical transmission had only limited applications due to their slow response speeds, unnecessary color switching, and low durability, stability, and safety.
The optical transmission modulation contrast achieved by controlling the light scattering interfaces on non-periodic 2D surface structures that often have low optical density such as cracks, wrinkles, and pillars is also generally low. In addition, since the light scattering interfaces are exposed and not subject to any passivation, they can be vulnerable to external damage and may lose optical transmission modulation functions. Furthermore, in-plane scattering interfaces that randomly exist on the surface make large-area modulation with uniformity difficult.
Inspired by these limitations, a KAIST research team led by Professor Seokwoo Jeon from the Department of Materials Science and Engineering and Professor Jung-Wuk Hong of the Civil and Environmental Engineering Department used proximity-field nanopatterning (PnP) technology that effectively produces highly periodic 3D hybrid nanostructures, and an atomic layer deposition (ALD) technique that allows the precise control of oxide deposition and the high-quality fabrication of semiconductor devices.
The team then successfully produced a large-scale smart optical film with a size of 3 by 3 inches in which ultrathin alumina nanoshells are inserted between the elastomers in a periodic 3D nanonetwork.
This "mechano-responsive" 3D hybrid nanocomposite film with a highly periodic network structure is the largest smart optical transmission modulation film that exists. The film has been shown to have state-of-the-art optical transmission modulation of up to 74% at visible wavelengths from 90% initial transmission to 16% in the scattering state under strain. Its durability and stability were proved by more than 10,000 tests of harsh mechanical deformation including stretching, releasing, bending, and being placed under high temperatures of up to 70°C. When this film was used, the transmittance of the smart window device was adjusted promptly and automatically within one second in response to the surrounding light conditions. Through these experiments, the underlying physics of optical scattering phenomena occurring in the heterogeneous interfaces were identified. Their findings were reported in the online edition of Advanced Science on April 26. KAIST Professor Jong-Hwa Shin's group and Professor Young-Seok Shim at Silla University also collaborated on this project.
Donghwi Cho, a PhD candidate in materials science and engineering at KAIST and co-lead author of the study, said, "Our smart optical film technology can better control high-contrast optical transmittance by relatively simple operating principles and with low energy consumption and costs."
Read more at Science Daily
The proposed 3D hybrid nanocomposite film with a highly periodic network structure has empirically demonstrated its high speed and performance, enabling the smart window to quantify and self-regulate its high-contrast optical transmittance. As a proof of concept, a mobile-app-enabled smart window device for Internet of Things (IoT) applications has been realized using the proposed smart optical film with successful expansion to the 3-by-3-inch scale. This energy-efficient and cost-effective technology holds great promise for future use in various applications that require active optical transmission modulation.
Flexible optical transmission modulation technologies for smart applications including privacy-protection windows, zero-energy buildings, and beam projection screens have been in the spotlight in recent years. Conventional technologies that used external stimuli such as electricity, heat, or light to modulate optical transmission had only limited applications due to their slow response speeds, unnecessary color switching, and low durability, stability, and safety.
The optical transmission modulation contrast achieved by controlling the light scattering interfaces on non-periodic 2D surface structures that often have low optical density such as cracks, wrinkles, and pillars is also generally low. In addition, since the light scattering interfaces are exposed and not subject to any passivation, they can be vulnerable to external damage and may lose optical transmission modulation functions. Furthermore, in-plane scattering interfaces that randomly exist on the surface make large-area modulation with uniformity difficult.
Inspired by these limitations, a KAIST research team led by Professor Seokwoo Jeon from the Department of Materials Science and Engineering and Professor Jung-Wuk Hong of the Civil and Environmental Engineering Department used proximity-field nanopatterning (PnP) technology that effectively produces highly periodic 3D hybrid nanostructures, and an atomic layer deposition (ALD) technique that allows the precise control of oxide deposition and the high-quality fabrication of semiconductor devices.
The team then successfully produced a large-scale smart optical film with a size of 3 by 3 inches in which ultrathin alumina nanoshells are inserted between the elastomers in a periodic 3D nanonetwork.
This "mechano-responsive" 3D hybrid nanocomposite film with a highly periodic network structure is the largest smart optical transmission modulation film that exists. The film has been shown to have state-of-the-art optical transmission modulation of up to 74% at visible wavelengths from 90% initial transmission to 16% in the scattering state under strain. Its durability and stability were proved by more than 10,000 tests of harsh mechanical deformation including stretching, releasing, bending, and being placed under high temperatures of up to 70°C. When this film was used, the transmittance of the smart window device was adjusted promptly and automatically within one second in response to the surrounding light conditions. Through these experiments, the underlying physics of optical scattering phenomena occurring in the heterogeneous interfaces were identified. Their findings were reported in the online edition of Advanced Science on April 26. KAIST Professor Jong-Hwa Shin's group and Professor Young-Seok Shim at Silla University also collaborated on this project.
Donghwi Cho, a PhD candidate in materials science and engineering at KAIST and co-lead author of the study, said, "Our smart optical film technology can better control high-contrast optical transmittance by relatively simple operating principles and with low energy consumption and costs."
Read more at Science Daily
Scientists find a switch to flip and turn off breast cancer growth and metastasis
Researchers at Tulane University School of Medicine identified a gene that causes an aggressive form of breast cancer to rapidly grow. More importantly, they have also discovered a way to "turn it off" and inhibit cancer from occurring. The animal study results have been so compelling that the team is now working on FDA approval to begin clinical trials and has published details in the journal Scientific Reports.
The team led by Dr. Reza Izadpanah examined the role two genes, including one whose involvement in cancer was discovered by Tulane researchers, play in causing triple negative breast cancer (TNBC). TNBC is considered to be the most aggressive of breast cancers, with a much poorer prognosis for treatment and survival. Izadpanah's team specifically identified an inhibitor of the TRAF3IP2 gene, which was proven to suppress the growth and spread (metastasis) of TNBC in mouse models that closely resemble humans.
In parallel studies looking at a duo of genes -- TRAF3IP2 and Rab27a, which play roles in the secretion of substances that can cause tumor formation -- the research teams studied what happens when they were stopped from functioning. Suppressing the expression of either gene led to a decline in both tumor growth and the spread of cancer to other organs. Izadpanah says that when Rab27a was silenced, the tumor did not grow but was still spreading a small number of cancer cells to other parts of the body. However, when the TRAF3IP2 gene was turned off, they found no spread (known as "metastasis" or "micrometastasis") of the original tumor cells for a full year following the treatment. Even more beneficial, inhibiting the TRAF3IP2 gene not only stopped future tumor growth but caused existing tumors to shrink to undetectable levels.
"Our findings show that both genes play a role in breast cancer growth and metastasis," says Izadpanah. "While targeting Rab27a delays progression of tumor growth, it fails to affect the spread of tiny amounts of cancer cells, or micrometastasis. On the contrary, targeting TRAF3IP2 suppresses tumor growth and spread, and interfering with it both shrinks pre-formed tumors and prevents additional spread. This exciting discovery has revealed that TRAF3IP2 can play a role as a novel therapeutic target in breast cancer treatment."
Read more at Science Daily
The team led by Dr. Reza Izadpanah examined the role two genes, including one whose involvement in cancer was discovered by Tulane researchers, play in causing triple negative breast cancer (TNBC). TNBC is considered to be the most aggressive of breast cancers, with a much poorer prognosis for treatment and survival. Izadpanah's team specifically identified an inhibitor of the TRAF3IP2 gene, which was proven to suppress the growth and spread (metastasis) of TNBC in mouse models that closely resemble humans.
In parallel studies looking at a duo of genes -- TRAF3IP2 and Rab27a, which play roles in the secretion of substances that can cause tumor formation -- the research teams studied what happens when they were stopped from functioning. Suppressing the expression of either gene led to a decline in both tumor growth and the spread of cancer to other organs. Izadpanah says that when Rab27a was silenced, the tumor did not grow but was still spreading a small number of cancer cells to other parts of the body. However, when the TRAF3IP2 gene was turned off, they found no spread (known as "metastasis" or "micrometastasis") of the original tumor cells for a full year following the treatment. Even more beneficial, inhibiting the TRAF3IP2 gene not only stopped future tumor growth but caused existing tumors to shrink to undetectable levels.
"Our findings show that both genes play a role in breast cancer growth and metastasis," says Izadpanah. "While targeting Rab27a delays progression of tumor growth, it fails to affect the spread of tiny amounts of cancer cells, or micrometastasis. On the contrary, targeting TRAF3IP2 suppresses tumor growth and spread, and interfering with it both shrinks pre-formed tumors and prevents additional spread. This exciting discovery has revealed that TRAF3IP2 can play a role as a novel therapeutic target in breast cancer treatment."
Read more at Science Daily
Gene discovery in fruit flies 'opens new doors' for hearing loss cure in elderly
Scientists at UCL have discovered sets of regulatory genes, which are responsible for maintaining healthy hearing. The finding, made in fruit flies, could potentially lead to treatments for age-related hearing loss (ARHL) in humans.
Globally one third of people (1.23 billion people) aged over 65 experience hearing impairment, and while there are thought to be more than 150 candidate genes which may affect hearing loss, there is no unified view on how to use these to develop novel preventive or curative hearing loss therapies.
In the study, published in Scientific Reports, researchers at the UCL Ear Institute assessed the hearing ability of the common fruit fly (Drosophila melanogaster) across its life span (around 70 days*), to see if their hearing declines with age.
The fruit fly is a powerful model in biology and its ear shares many molecular similarities with the ears of humans, which make it an ideal tool for the study of human hearing loss. However, so far, no study had assessed the fruit flies' hearing across their life course.
Using advanced biomechanical, neurophysiological and behavioural techniques**, the researchers found that the antennal ears of fruit flies also display ARHL with nearly all measures of sensitive hearing starting to decline after 50 days of age.
With this knowledge, the researchers turned their interest to the time before flies developed ARHL: they wanted to know if there were any 'age-variable' genes in the flies' Johnston's Organ (their 'inner ear'), which have kept the ears healthy for 50 days of their lives.
Using a combination of molecular biology, bioinformatics and mutant analysis, the researchers identified a new set of transcriptional regulator genes: these are so called 'homeostasis genes', meaning they are the genetic actuators, so they control the activity which keeps the ear sensitive.
For researchers, one of the principle advantages of the fruit fly model is that it allows for easily testing the roles of individual genes by either increasing their function (overexpression) or silencing them (RNAi interference). Exploiting these tools, researchers also found that manipulating some of the homeostasis genes could prevent the flies from getting ARHL.
Lead author Professor Joerg Albert (UCL Ear Institute) said: "While many studies have been conducted into the hearing function of fruit flies, ours is the first to look at the mechanistic and molecular detail of their auditory life course.
"Our twin discoveries that fruit flies experience age-related hearing loss and that their prior auditory health is controlled by a particular set of genes, is a significant breakthrough. The fact that these genes are conserved in humans will also help to focus future clinical research in humans and thereby accelerate the discovery of novel pharmacological or gene-therapeutic strategies.
"Building on our findings from Drosophila, we have already started a follow-up drug discovery project designed to fast-track novel treatments for human ARHL."
Dr Ralph Holme, Executive Director of Research at Action on Hearing Loss, said: 'We urgently need to find effective treatments able to prevent or slow the loss of hearing as we age.
"Hearing loss affects 70% of people aged over 70 years old, cutting people off from friends and family.
"Action on Hearing Loss is proud to have been able to support this exciting research that has identified genes involved in maintaining hearing.
"It not only advances our understanding of why hearing declines with age, but importantly also opens the door to the future development of treatments to prevent it."
*At 25 degrees, one day for a fruit fly is equivalent (approximately) to one year for a human.
Read more at Science Daily
Globally one third of people (1.23 billion people) aged over 65 experience hearing impairment, and while there are thought to be more than 150 candidate genes which may affect hearing loss, there is no unified view on how to use these to develop novel preventive or curative hearing loss therapies.
In the study, published in Scientific Reports, researchers at the UCL Ear Institute assessed the hearing ability of the common fruit fly (Drosophila melanogaster) across its life span (around 70 days*), to see if their hearing declines with age.
The fruit fly is a powerful model in biology and its ear shares many molecular similarities with the ears of humans, which make it an ideal tool for the study of human hearing loss. However, so far, no study had assessed the fruit flies' hearing across their life course.
Using advanced biomechanical, neurophysiological and behavioural techniques**, the researchers found that the antennal ears of fruit flies also display ARHL with nearly all measures of sensitive hearing starting to decline after 50 days of age.
With this knowledge, the researchers turned their interest to the time before flies developed ARHL: they wanted to know if there were any 'age-variable' genes in the flies' Johnston's Organ (their 'inner ear'), which have kept the ears healthy for 50 days of their lives.
Using a combination of molecular biology, bioinformatics and mutant analysis, the researchers identified a new set of transcriptional regulator genes: these are so called 'homeostasis genes', meaning they are the genetic actuators, so they control the activity which keeps the ear sensitive.
For researchers, one of the principle advantages of the fruit fly model is that it allows for easily testing the roles of individual genes by either increasing their function (overexpression) or silencing them (RNAi interference). Exploiting these tools, researchers also found that manipulating some of the homeostasis genes could prevent the flies from getting ARHL.
Lead author Professor Joerg Albert (UCL Ear Institute) said: "While many studies have been conducted into the hearing function of fruit flies, ours is the first to look at the mechanistic and molecular detail of their auditory life course.
"Our twin discoveries that fruit flies experience age-related hearing loss and that their prior auditory health is controlled by a particular set of genes, is a significant breakthrough. The fact that these genes are conserved in humans will also help to focus future clinical research in humans and thereby accelerate the discovery of novel pharmacological or gene-therapeutic strategies.
"Building on our findings from Drosophila, we have already started a follow-up drug discovery project designed to fast-track novel treatments for human ARHL."
Dr Ralph Holme, Executive Director of Research at Action on Hearing Loss, said: 'We urgently need to find effective treatments able to prevent or slow the loss of hearing as we age.
"Hearing loss affects 70% of people aged over 70 years old, cutting people off from friends and family.
"Action on Hearing Loss is proud to have been able to support this exciting research that has identified genes involved in maintaining hearing.
"It not only advances our understanding of why hearing declines with age, but importantly also opens the door to the future development of treatments to prevent it."
*At 25 degrees, one day for a fruit fly is equivalent (approximately) to one year for a human.
Read more at Science Daily
Jun 1, 2020
New study provides maps, ice favorability index to companies looking to mine the moon
The 49ers who panned for gold during California's Gold Rush didn't really know where they might strike it rich. They had word of mouth and not much else to go on.
Researchers at the University of Central Florida want to give prospectors looking to mine the moon better odds of striking gold, which on the moon means rich deposits of water ice that can be turned into resources, like fuel, for space missions.
A team lead by planetary scientist Kevin Cannon created an Ice Favorability Index. The geological model explains the process for ice formation at the poles of the moon, and mapped the terrain, which includes craters that may hold ice deposits. The model, which has been published in the peer-reviewed journal Icarus, accounts for what asteroid impacts on the surface of the moon may do to deposits of ice found meters beneath the surface.
"Despite being our closest neighbor, we still don't know a lot about water on the moon, especially how much there is beneath the surface," Cannon says. "It's important for us to consider the geologic processes that have gone on to better understand where we may find ice deposits and how to best get to them with the least amount of risk."
The team was inspired by mining companies on Earth, which conduct detailed geological work, and take core samples before investing in costly extraction sites. Mining companies conduct field mappings, take core samples from the potential site and try to understand the geological reasons behind the formation of the particular mineral they are looking for in an area of interest. In essence they create a model for what a mining zone might look like before deciding to plunk down money to drill.
The team at UCF followed the same approach using data collected about the moon over the years and ran simulations in the lab. While they couldn't collect core samples, they had data from satellite observations and from the first trip to the moon.
Why Mine the Moon
In order for humans to explore the solar system and beyond, spacecraft have to be able to launch and continue on their long missions. One of the challenges is fuel. There are no gas stations in space, which means spacecraft have to carry extra fuel with them for long missions and that fuel weighs a lot. Mining the moon could result in creating fuel , which would help ease the cost of flights since spacecraft wouldn't have to haul the extra fuel.
Water ice can be purified and processed to produce both hydrogen and oxygen for propellent, according to several previously published studies. Sometime in the future, this process could be completed on the moon effectively producing a gas station for spacecraft. Asteroids may also provide similar resources for fuel.
Some believe a system of these "gas stations" would be the start of the industrialization of space.
Several private companies are exploring mining techniques to employ on the moon. Both Luxembourg and the United States have adopted legislation giving citizens and corporations ownership rights over resources mined in space, including the moon, according to the study.
"The idea of mining the moon and asteroids isn't science fiction anymore," says UCF physics Professor and co-author Dan Britt. "There are teams around the world looking to find ways to make this happen and our work will help get us closer to making the idea a reality."
Read more at Science Daily
Researchers at the University of Central Florida want to give prospectors looking to mine the moon better odds of striking gold, which on the moon means rich deposits of water ice that can be turned into resources, like fuel, for space missions.
A team lead by planetary scientist Kevin Cannon created an Ice Favorability Index. The geological model explains the process for ice formation at the poles of the moon, and mapped the terrain, which includes craters that may hold ice deposits. The model, which has been published in the peer-reviewed journal Icarus, accounts for what asteroid impacts on the surface of the moon may do to deposits of ice found meters beneath the surface.
"Despite being our closest neighbor, we still don't know a lot about water on the moon, especially how much there is beneath the surface," Cannon says. "It's important for us to consider the geologic processes that have gone on to better understand where we may find ice deposits and how to best get to them with the least amount of risk."
The team was inspired by mining companies on Earth, which conduct detailed geological work, and take core samples before investing in costly extraction sites. Mining companies conduct field mappings, take core samples from the potential site and try to understand the geological reasons behind the formation of the particular mineral they are looking for in an area of interest. In essence they create a model for what a mining zone might look like before deciding to plunk down money to drill.
The team at UCF followed the same approach using data collected about the moon over the years and ran simulations in the lab. While they couldn't collect core samples, they had data from satellite observations and from the first trip to the moon.
Why Mine the Moon
In order for humans to explore the solar system and beyond, spacecraft have to be able to launch and continue on their long missions. One of the challenges is fuel. There are no gas stations in space, which means spacecraft have to carry extra fuel with them for long missions and that fuel weighs a lot. Mining the moon could result in creating fuel , which would help ease the cost of flights since spacecraft wouldn't have to haul the extra fuel.
Water ice can be purified and processed to produce both hydrogen and oxygen for propellent, according to several previously published studies. Sometime in the future, this process could be completed on the moon effectively producing a gas station for spacecraft. Asteroids may also provide similar resources for fuel.
Some believe a system of these "gas stations" would be the start of the industrialization of space.
Several private companies are exploring mining techniques to employ on the moon. Both Luxembourg and the United States have adopted legislation giving citizens and corporations ownership rights over resources mined in space, including the moon, according to the study.
"The idea of mining the moon and asteroids isn't science fiction anymore," says UCF physics Professor and co-author Dan Britt. "There are teams around the world looking to find ways to make this happen and our work will help get us closer to making the idea a reality."
Read more at Science Daily
Asymmetry found in spin directions of galaxies
An analysis of more than 200,000 spiral galaxies has revealed unexpected links between spin directions of galaxies, and the structure formed by these links might suggest that the early universe could have been spinning, according to a Kansas State University study.
Lior Shamir, a K-State computational astronomer and computer scientist, presented the findings at the 236th American Astronomical Society meeting in June 2020. The findings are significant because the observations conflict with some previous assumptions about the large-scale structure of the universe.
Since the time of Edwin Hubble, astronomers have believed that the universe is inflating with no particular direction and that the galaxies in it are distributed with no particular cosmological structure. But Shamir's recent observations of geometrical patterns of more than 200,000 spiral galaxies suggest that the universe could have a defined structure and that the early universe could have been spinning. Patterns in the distribution of these galaxies suggest that spiral galaxies in different parts of the universe, separated by both space and time, are related through the directions toward which they spin, according to the study.
"Data science in astronomy has not just made astronomy research more cost-effective, but it also allows us to observe the universe in a completely different way," said Shamir, also a K-State associate professor of computer science. "The geometrical pattern exhibited by the distribution of the spiral galaxies is clear, but can only be observed when analyzing a very large number of astronomical objects."
A spiral galaxy is a unique astronomical object because its visual appearance depends on the observer's perspective. For instance, a spiral galaxy that spins clockwise when observed from Earth, would seem to spin counterclockwise when the observer is located in the opposite side of that galaxy. If the universe is isotropic and has no particular structure -- as previous astronomers have predicted -- the number of galaxies that spin clockwise would be roughly equal to the number of galaxies that spin counterclockwise. Shamir used data from modern telescopes to show that this is not the case.
With traditional telescopes, counting galaxies in the universe is a daunting task. But modern robotic telescopes such as the Sloan Digital Sky Survey, or SDSS, and the Panoramic Survey Telescope and Rapid Response System, or Pan-STARRS, are able to image many millions of galaxies automatically as they survey the sky. Machine vision can then sort millions of galaxies by their spin direction far faster than any person or group of people.
When comparing the number of galaxies with different spin directions, the number of galaxies that spin clockwise is not equal to the number of galaxies that spin counterclockwise. The difference is small, just over 2%, but with the high number of galaxies, there is a probability of less than 1 to 4 billion to have such asymmetry by chance, according to Shamir's research.
The patterns span over more than 4 billion light-years, but the asymmetry in that range is not uniform. The study found that the asymmetry gets higher when the galaxies are more distant from Earth, which shows that the early universe was more consistent and less chaotic than the current universe.
But the patterns do not just show that the universe is not symmetric, but also that the asymmetry changes in different parts of the universe, and the differences exhibit a unique pattern of multipoles.
"If the universe has an axis, it is not a simple single axis like a merry-go-round," Shamir said. "It is a complex alignment of multiple axes that also have a certain drift."
The concept of cosmological multipoles is not new. Previous space-based observatories -- such as the Cosmic Background Explorer, or COBE, satellite; the Wilkinson Microwave Anisotropy Probe, or WMAP mission; and the Planck observatory -- showed that the cosmic microwave background, which is electromagnetic radiation from the very early universe, also exhibits multiple poles. But the measurement of the cosmic microwave background is sensitive to foreground contamination -- such as the obstruction of the Milky Way -- and cannot show how these poles changed over time. The asymmetry between spin directions of spiral galaxies is a measurement that is not sensitive to obstruction. What can obstruct galaxies spinning in one direction in a certain field will necessarily also obstruct galaxies spinning in the opposite way.
Read more at Science Daily
Lior Shamir, a K-State computational astronomer and computer scientist, presented the findings at the 236th American Astronomical Society meeting in June 2020. The findings are significant because the observations conflict with some previous assumptions about the large-scale structure of the universe.
Since the time of Edwin Hubble, astronomers have believed that the universe is inflating with no particular direction and that the galaxies in it are distributed with no particular cosmological structure. But Shamir's recent observations of geometrical patterns of more than 200,000 spiral galaxies suggest that the universe could have a defined structure and that the early universe could have been spinning. Patterns in the distribution of these galaxies suggest that spiral galaxies in different parts of the universe, separated by both space and time, are related through the directions toward which they spin, according to the study.
"Data science in astronomy has not just made astronomy research more cost-effective, but it also allows us to observe the universe in a completely different way," said Shamir, also a K-State associate professor of computer science. "The geometrical pattern exhibited by the distribution of the spiral galaxies is clear, but can only be observed when analyzing a very large number of astronomical objects."
A spiral galaxy is a unique astronomical object because its visual appearance depends on the observer's perspective. For instance, a spiral galaxy that spins clockwise when observed from Earth, would seem to spin counterclockwise when the observer is located in the opposite side of that galaxy. If the universe is isotropic and has no particular structure -- as previous astronomers have predicted -- the number of galaxies that spin clockwise would be roughly equal to the number of galaxies that spin counterclockwise. Shamir used data from modern telescopes to show that this is not the case.
With traditional telescopes, counting galaxies in the universe is a daunting task. But modern robotic telescopes such as the Sloan Digital Sky Survey, or SDSS, and the Panoramic Survey Telescope and Rapid Response System, or Pan-STARRS, are able to image many millions of galaxies automatically as they survey the sky. Machine vision can then sort millions of galaxies by their spin direction far faster than any person or group of people.
When comparing the number of galaxies with different spin directions, the number of galaxies that spin clockwise is not equal to the number of galaxies that spin counterclockwise. The difference is small, just over 2%, but with the high number of galaxies, there is a probability of less than 1 to 4 billion to have such asymmetry by chance, according to Shamir's research.
The patterns span over more than 4 billion light-years, but the asymmetry in that range is not uniform. The study found that the asymmetry gets higher when the galaxies are more distant from Earth, which shows that the early universe was more consistent and less chaotic than the current universe.
But the patterns do not just show that the universe is not symmetric, but also that the asymmetry changes in different parts of the universe, and the differences exhibit a unique pattern of multipoles.
"If the universe has an axis, it is not a simple single axis like a merry-go-round," Shamir said. "It is a complex alignment of multiple axes that also have a certain drift."
The concept of cosmological multipoles is not new. Previous space-based observatories -- such as the Cosmic Background Explorer, or COBE, satellite; the Wilkinson Microwave Anisotropy Probe, or WMAP mission; and the Planck observatory -- showed that the cosmic microwave background, which is electromagnetic radiation from the very early universe, also exhibits multiple poles. But the measurement of the cosmic microwave background is sensitive to foreground contamination -- such as the obstruction of the Milky Way -- and cannot show how these poles changed over time. The asymmetry between spin directions of spiral galaxies is a measurement that is not sensitive to obstruction. What can obstruct galaxies spinning in one direction in a certain field will necessarily also obstruct galaxies spinning in the opposite way.
Read more at Science Daily
Cancer cells cause inflammation to protect themselves from viruses
Researchers at the Francis Crick Institute have uncovered how cancer cells protect themselves from viruses that are harmful to tumours but not to healthy cells. These findings could lead to improved viral treatments for the disease.
In their study, published in Nature Cell Biology, the researchers identified a mechanism that protects cancer cells from oncolytic viruses, which preferentially infect and kill cancer cells.
These viruses are sometimes used as a treatment to destroy cancer cells and stimulate an immune response against the tumour. However, they only work in a minority of patients and the reasons whether they are effective or not are not yet fully understood.
The team examined the environment surrounding a tumour and how cancer cells interact with their neighbours, in particular, cancer-associated fibroblasts (CAFs), which researchers know play a significant role in cancer protection, growth and spread.
They found that when cancer cells are in direct contact with CAFs, this leads to inflammation that can alert the surrounding tissue, making it harder for viruses to invade and replicate within the cancer cell.
This protective inflammatory response occurs when cancer cells pass small amounts of cytoplasm, the fluid in their cells, through to the CAFs. This triggers the fibroblasts to signal to nearby cells to release cytokines, molecules that cause inflammation.*
Erik Sahai, paper author and group leader of the Tumour Cell Biology Laboratory at the Crick says: "This process only occurs when cancer cells and fibroblasts are in direct contact with each other. In healthy tissue, this type of inflammatory response would only happen during injury, as there is usually a membrane keeping them apart.
"This is an excellent example of the way cancer hijacks our body's protective mechanisms for its own gain."
Importantly, when the researchers blocked the signalling pathway in cell cultures and in tumours grown in the laboratory, they found that the cancer cells became more sensitive to oncolytic viruses.
They hope these findings may, in the future, help to develop a treatment that could modulate the inflammation and so help oncolytic viruses to more effectively target cancer cells.
Emma Milford, co-lead author and Phd student in the Tumour Cell Biology Laboratory at the Crick says: "If we can more fully understand how cancer cells protect themselves from oncolytic viruses and find effective ways to stop these protective mechanisms, these viruses could become a more powerful tool doctors can use to treat cancer. This research is an important, early step towards this."
Antonio Rullan, co-lead author and clinical research fellow in the Tumour Cell Biology Laboratory at the Crick adds: "These viruses prefer to target cancer cells over healthy cells, which has made them of interest for scientists over the last few decades. However, much more remains to be understood about how they interact with tumours and the immune system."
Read more at Science Daily
In their study, published in Nature Cell Biology, the researchers identified a mechanism that protects cancer cells from oncolytic viruses, which preferentially infect and kill cancer cells.
These viruses are sometimes used as a treatment to destroy cancer cells and stimulate an immune response against the tumour. However, they only work in a minority of patients and the reasons whether they are effective or not are not yet fully understood.
The team examined the environment surrounding a tumour and how cancer cells interact with their neighbours, in particular, cancer-associated fibroblasts (CAFs), which researchers know play a significant role in cancer protection, growth and spread.
They found that when cancer cells are in direct contact with CAFs, this leads to inflammation that can alert the surrounding tissue, making it harder for viruses to invade and replicate within the cancer cell.
This protective inflammatory response occurs when cancer cells pass small amounts of cytoplasm, the fluid in their cells, through to the CAFs. This triggers the fibroblasts to signal to nearby cells to release cytokines, molecules that cause inflammation.*
Erik Sahai, paper author and group leader of the Tumour Cell Biology Laboratory at the Crick says: "This process only occurs when cancer cells and fibroblasts are in direct contact with each other. In healthy tissue, this type of inflammatory response would only happen during injury, as there is usually a membrane keeping them apart.
"This is an excellent example of the way cancer hijacks our body's protective mechanisms for its own gain."
Importantly, when the researchers blocked the signalling pathway in cell cultures and in tumours grown in the laboratory, they found that the cancer cells became more sensitive to oncolytic viruses.
They hope these findings may, in the future, help to develop a treatment that could modulate the inflammation and so help oncolytic viruses to more effectively target cancer cells.
Emma Milford, co-lead author and Phd student in the Tumour Cell Biology Laboratory at the Crick says: "If we can more fully understand how cancer cells protect themselves from oncolytic viruses and find effective ways to stop these protective mechanisms, these viruses could become a more powerful tool doctors can use to treat cancer. This research is an important, early step towards this."
Antonio Rullan, co-lead author and clinical research fellow in the Tumour Cell Biology Laboratory at the Crick adds: "These viruses prefer to target cancer cells over healthy cells, which has made them of interest for scientists over the last few decades. However, much more remains to be understood about how they interact with tumours and the immune system."
Read more at Science Daily
Monitoring environmental exposures in dogs could be early warning system for human health
Man's best friend may also be man's best bet for figuring out how environmental chemicals could impact our health. Researchers from North Carolina State University and Duke University's Nicholas School of the Environment used silicone dog tags as passive environmental samplers to collect information about everyday chemical exposures, and found that dogs could be an important sentinel species for the long term effects of environmental chemicals.
"Silicone monitoring devices are still relatively new, but they represent an inexpensive and effective way to measure exposure to the chemicals we encounter in daily life -- from pesticides to flame retardants," says Catherine Wise, Ph.D. candidate at NC State and lead author of a paper describing the work. "And we know that many human diseases caused by environmental exposure are similar clinically and biologically to those found in dogs."
Wise and researchers from NC State and Duke recruited 30 dogs and their owners to wear silicone monitors for a five-day period in July 2018. Humans wore wristbands, while the dogs wore tags on their collars.
The researchers analyzed the wristbands and tags for exposures to chemicals within three classes of environmental toxicants that are often found in human blood and urine: pesticides, flame retardants, and phthalates, which are found in plastic food packaging and personal care products. They found high correlations between exposure levels for owners and their pets. Urinalysis also revealed the presence of organophosphate esters (found in some flame retardants) in both owners and dogs.
"What was remarkable about these results were the similar patterns of exposure between people and their pets," says Heather Stapleton, Ronie-Richelle Garcia-Johnson Distinguished Professor, director of the Duke Environmental Analysis Laboratory at the Nicholas School and co-author of the research. "It's quite clear that the home environment contributes strongly to our daily exposure to chemical contaminants."
However, while dogs and humans may share similar exposures, the health effects do not follow similar timelines -- a fact that could aid researchers in teasing out relationships between chemical exposure and human health. "Dogs are special when it comes to linking exposures and disease outcomes because effects that may take decades to show up in humans can occur in one to two years in a dog," Wise says.
"Humans spend incredible amounts of time with their dogs -- that's especially true right now," says Matthew Breen, Oscar J. Fletcher Distinguished Professor of Comparative Oncology Genetics at NC State and corresponding author of the paper. "If we develop ways to correlate dog disease with their exposures over time, it may give human-health professionals the opportunity to mitigate these exposures for both species. Dogs are a powerful biological sentinel species for human disease."
From Science Daily
"Silicone monitoring devices are still relatively new, but they represent an inexpensive and effective way to measure exposure to the chemicals we encounter in daily life -- from pesticides to flame retardants," says Catherine Wise, Ph.D. candidate at NC State and lead author of a paper describing the work. "And we know that many human diseases caused by environmental exposure are similar clinically and biologically to those found in dogs."
Wise and researchers from NC State and Duke recruited 30 dogs and their owners to wear silicone monitors for a five-day period in July 2018. Humans wore wristbands, while the dogs wore tags on their collars.
The researchers analyzed the wristbands and tags for exposures to chemicals within three classes of environmental toxicants that are often found in human blood and urine: pesticides, flame retardants, and phthalates, which are found in plastic food packaging and personal care products. They found high correlations between exposure levels for owners and their pets. Urinalysis also revealed the presence of organophosphate esters (found in some flame retardants) in both owners and dogs.
"What was remarkable about these results were the similar patterns of exposure between people and their pets," says Heather Stapleton, Ronie-Richelle Garcia-Johnson Distinguished Professor, director of the Duke Environmental Analysis Laboratory at the Nicholas School and co-author of the research. "It's quite clear that the home environment contributes strongly to our daily exposure to chemical contaminants."
However, while dogs and humans may share similar exposures, the health effects do not follow similar timelines -- a fact that could aid researchers in teasing out relationships between chemical exposure and human health. "Dogs are special when it comes to linking exposures and disease outcomes because effects that may take decades to show up in humans can occur in one to two years in a dog," Wise says.
"Humans spend incredible amounts of time with their dogs -- that's especially true right now," says Matthew Breen, Oscar J. Fletcher Distinguished Professor of Comparative Oncology Genetics at NC State and corresponding author of the paper. "If we develop ways to correlate dog disease with their exposures over time, it may give human-health professionals the opportunity to mitigate these exposures for both species. Dogs are a powerful biological sentinel species for human disease."
From Science Daily
May 31, 2020
Dinosaur-dooming asteroid struck Earth at 'deadliest possible' angle
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| Dinosaurs and asteroid illustration |
The simulations show that the asteroid hit Earth at an angle of about 60 degrees, which maximised the amount of climate-changing gases thrust into the upper atmosphere.
Such a strike likely unleashed billions of tonnes of sulphur, blocking the sun and triggering the nuclear winter that killed the dinosaurs and 75 per cent of life on Earth 66 million years ago.
Drawn from a combination of 3D numerical impact simulations and geophysical data from the site of the impact, the new models are the first ever fully 3D simulations to reproduce the whole event -- from the initial impact to the moment the final crater, now known as Chicxulub, was formed.
The simulations were performed on the Science and Technology Facilities Council (STFC) DiRAC High Performance Computing Facility.
Lead researcher Professor Gareth Collins, of Imperial's Department of Earth Science and Engineering, said: "For the dinosaurs, the worst-case scenario is exactly what happened. The asteroid strike unleashed an incredible amount of climate-changing gases into the atmosphere, triggering a chain of events that led to the extinction of the dinosaurs. This was likely worsened by the fact that it struck at one of the deadliest possible angles.
"Our simulations provide compelling evidence that the asteroid struck at a steep angle, perhaps 60 degrees above the horizon, and approached its target from the north-east. We know that this was among the worst-case scenarios for the lethality on impact, because it put more hazardous debris into the upper atmosphere and scattered it everywhere -- the very thing that led to a nuclear winter."
The results are published today in Nature Communications.
Crater creation
The upper layers of earth around the Chicxulub crater in present-day Mexico contain high amounts of water as well as porous carbonate and evaporite rocks. When heated and disturbed by the impact, these rocks would have decomposed, flinging vast amounts of carbon dioxide, sulphur and water vapour into the atmosphere.
The sulphur would have been particularly hazardous as it rapidly forms aerosols -- tiny particles that would have blocked the sun's rays, halting photosynthesis in plants and rapidly cooling the climate. This eventually contributed to the mass extinction event that killed 75 per cent of life on Earth.
The team of researchers from Imperial, the University of Freiburg, and The University of Texas at Austin, examined the shape and subsurface structure of the crater using geophysical data to feed into the simulations that helped diagnose the impact angle and direction. Their analysis was also informed by recent results from drilling into the 200 km-wide crater, which brought up rocks containing evidence of the extreme forces generated by the impact.
Peak performance
Pivotal to diagnosing the angle and direction of impact was the relationship between the centre of the crater, the centre of the peak ring -- a ring of mountains made of heavily fractured rock inside the crater rim -- and the centre of dense uplifted mantle rocks, some 30 km beneath the crater.
At Chicxulub, these centres are aligned in a southwest-northeast direction, with the crater centre in between the peak-ring and mantle-uplift centres. The team's 3D Chicxulub crater simulations at an angle of 60 degrees reproduced these observations almost exactly.
The simulations reconstructed the crater formation in unprecedented detail and give us more clues as to how the largest craters on Earth are formed. Previous fully 3D simulations of the Chicxulub impact have covered only the early stages of impact, which include the production of a deep bowl-shaped hole in the crust known as the transient crater and the expulsion of rocks, water and sediment into the atmosphere.
These simulations are the first to continue beyond this intermediate point in the formation of the crater and reproduce the final stage of the crater's formation, in which the transient crater collapses to form the final structure. This allowed the researchers to make the first comparison between 3D Chicxulub crater simulations and the present-day structure of the crater revealed by geophysical data.
Co-author Dr Auriol Rae of the University of Freiburg said: "Despite being buried beneath nearly a kilometre of sedimentary rocks, it is remarkable that geophysical data reveals so much about the crater structure -- enough to describe the direction and angle of the impact."
The researchers say that while the study has given us important insights into the dinosaur-dooming impact, it also helps us understand how large craters on other planets form.
Co-author Dr Thomas Davison, also of Imperial's Department of Earth Science and Engineering, said: "Large craters like Chicxulub are formed in a matter of minutes, and involve a spectacular rebound of rock beneath the crater. Our findings could help advance our understanding of how this rebound can be used to diagnose details of the impacting asteroid."
Read more at Science Daily
Rarely heard narwhal vocalizations
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| Narwhal couple |
Narwhals are difficult to study because they are notoriously shy and skittish and spend most of their time deep in the freezing Arctic Ocean. They tend to summer in glacial fjords around Greenland and Canada, but scientists often have trouble getting close enough to study them. Glacier fronts can be dangerous and hard to access, and the animals tend to swim off when approached by motorized boats.
But Inuit hunters familiar with the mysterious cetaceans can get closer to the animals without disturbing them. In July 2019, researchers accompanied several Inuit whale hunting expeditions in Northwest Greenland to study the narwhals that summer there in more detail.
Using underwater microphones attached to small boats, the researchers captured narwhal social calls and foraging sounds, getting as close as 25 meters (82 feet) to the elusive cetaceans.
The recordings help the researchers provide a baseline of the kinds of sounds that permeate the narwhals' pristine habitat. In combination with sightings, they also show narwhals get closer to glacier ice than previously thought for this area and the animals do forage for food in summer, contrary to some previous findings.
"Their world is the soundscape of this glacial fjord," said Evgeny Podolskiy, a geophysicist at Hokkaido University in Sapporo, Japan and lead author of a new study detailing the findings in AGU's Journal of Geophysical Research: Oceans. "There are many questions we can answer by listening to glacier fjords in general."
Getting close
Podolskiy and his colleagues had been working in Greenland fjords for several years, studying the sounds made by melting glaciers. Coincidentally, a population of narwhals summers in the fjords they were studying, and Podolskiy saw an opportunity to study the wily creatures.
"I realized working in the area and not paying attention to the elephant in the room -- the key endemic legendary Arctic unicorn just flowing around our glacier -- was a big mistake," he said.
The researchers tagged along on several Inuit hunting expeditions departing from the village of Qaanaaq, placing microphones underwater and recording the baseline sounds of the fjord.
They captured several types of sounds made by narwhals, including social calls, or whistles, and clicks used for echolocation, the biological sonar used by dolphins, bats, some whales and other animals to navigate and find food.
The closer narwhals get to their food, the faster they click, until the noise becomes a buzz not unlike that of a chainsaw. This terminal buzz helps the narwhals pinpoint the location of their prey.
"If you approach and target these fast fish, you better know precisely where they are; you need to gather this information more frequently," Podolskiy said.
Few studies have documented narwhals feeding in the summertime. Because the microphones picked up terminal buzz, a sound associated with finding food, the new study provides further evidence that narwhals do forage in summer.
Surprisingly, the researchers found narwhals come roughly within 1 kilometer (half a mile) of a glacier calving front, despite the fact that these areas are some of the noisiest places in the ocean and calving icebergs can be dangerous.
Read more at Science Daily
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