ERIK MARTIN WILLÈN: November 2024

Saturday, November 2, 2024

Planets Beware: NASA Unburies Danger Zones of Star Cluster - UNIVERSE

X-ray: NASA/CXC/SAO/J. Drake et al, IR: NASA/JPL-Caltech/Spitzer; Image Processing: NASA/CXC/SAO/N. Wolk

Most stars form in collections, called clusters or associations, that include very massive stars. These giant stars send out large amounts of high-energy radiation, which can disrupt relatively fragile disks of dust and gas that are in the process of coalescing to form new planets.

A team of astronomers used NASA’s Chandra X-ray Observatory, in combination with ultraviolet, optical, and infrared data, to show where some of the most treacherous places in a star cluster may be, where planets’ chances to form are diminished.

The target of the observations was Cygnus OB2, which is the nearest large cluster of stars to our Sun — at a distance of about 4,600 light-years. The cluster contains hundreds of massive stars as well as thousands of lower-mass stars. The team used long Chandra observations pointing at different regions of Cygnus OB2, and the resulting set of images were then stitched together into one large image.

The deep Chandra observations mapped out the diffuse X-ray glow in between the stars, and they also provided an inventory of the young stars in the cluster. This inventory was combined with others using optical and infrared data to create the best census of young stars in the cluster.

In this new composite image, the Chandra data (purple) shows the diffuse X-ray emission and young stars in Cygnus OB2, and infrared data from NASA’s now-retired Spitzer Space Telescope (red, green, blue, and cyan) reveals young stars and the cooler dust and gas throughout the region.

In these crowded stellar environments, copious amounts of high-energy radiation produced by stars and planets are present. Together, X-rays and intense ultraviolet light can have a devastating impact on planetary disks and systems in the process of forming.

Planet-forming disks around stars naturally fade away over time. Some of the disk falls onto the star and some is heated up by X-ray and ultraviolet radiation from the star and evaporates in a wind. The latter process, known as “photoevaporation,” usually takes between 5 and 10 million years with average-sized stars before the disk disappears. If massive stars, which produce the most X-ray and ultraviolet radiation, are nearby, this process can be accelerated.

The researchers using this data found clear evidence that planet-forming disks around stars indeed disappear much faster when they are close to massive stars producing a lot of high-energy radiation. The disks also disappear more quickly in regions where the stars are more closely packed together.

For regions of Cygnus OB2 with less high-energy radiation and lower numbers of stars, the fraction of young stars with disks is about 40%. For regions with more high-energy radiation and higher numbers of stars, the fraction is about 18%. The strongest effect — meaning the worst place to be for a would-be planetary system — is within about 1.6 light-years of the most massive stars in the cluster.

A separate study by the same team examined the properties of the diffuse X-ray emission in the cluster. They found that the higher-energy diffuse emission comes from areas where winds of gas blowing away from massive stars have collided with each other. This causes the gas to become hotter and produce X-rays. The less energetic emission probably comes from gas in the cluster colliding with gas surrounding the cluster.

Two separate papers describing the Chandra data of Cygnus OB2 are available. The paper about the planetary danger zones, led by Mario Giuseppe Guarcello (National Institute for Astrophysics in Palermo, Italy), appeared in the November 2023 issue of the Astrophysical Journal Supplement Series, and is available here. The paper about the diffuse emission, led by Juan Facundo Albacete-Colombo (University of Rio Negro in Argentina) was published in the same issue of Astrophysical Journal Supplement, and is available here.

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.

JPL managed the Spitzer Space Telescope mission for NASA’s Science Mission Directorate in Washington until the mission was retired in January 2020. Science operations were conducted at the Spitzer Science Center at Caltech. Spacecraft operations were based at Lockheed Martin Space in Littleton, Colorado. Data are archived at the Infrared Science Archive operated by IPAC at Caltech. Caltech manages JPL for NASA.

Learn more about the Chandra X-ray Observatory and its mission here:

https://www.nasa.gov/chandra

https://chandra.si.edu

Visual Description

This release features a composite image of the Cygnus OB2 star cluster, which resembles a night sky blanketed in orange, purple, and grey clouds.

The center of the square image is dominated by purple haze. This haze represents diffuse X-ray emissions, and young stars, detected by the Chandra X-ray observatory. Surrounding the purple haze is a mottled, streaky, brick orange cloud. Another cloud resembling a tendril of grey smoke stretches from our lower left to the center of the image. These clouds represent relatively cool dust and gas observed by the Spitzer Space Telescope.

Although the interwoven clouds cover most of the image, the thousands of stars within the cluster shine through. The lower-mass stars present as tiny specks of light. The massive stars gleam, some with long refraction spikes.

By: Lee Mohon

Source: Planets Beware: NASA Unburies Danger Zones of Star Cluster - NASA

Guardian Landsat - Firewatch - NASA Goddard - EARTH

Zebrahub: New atlas tracks zebrafish development like never before

CZ Biohub SF scientists Loïc Royer (left) and Merlin Lange work on a light-sheet microscope designed and built at the Biohub. Credit: Dale Ramos

When early cartographers undertook perilous expeditions to map unknown corners of the world with sextants, compasses, and hand-drawn diagrams, it's unlikely they imagined that someday anyone with an internet connection would have access to a seamless view of the entire planet from the comfort of their own home.

Today, pioneering scientists are working to create a similar experience for a much tinier, but no less important domain: developing embryos. The goal is to track and map the behavior of each and every cell working together to create an adult lifeform, and present that map in a clickable, navigable display—a sort of Google Earth for developmental biology.

Now, in a paper published in Cell, researchers at the Chan Zuckerberg Biohub San Francisco (CZ Biohub SF) are unveiling the latest advancements in that effort.

"Zebrahub" is a state-of-the-art cell atlas that combines high-resolution time-lapse videos of newly emerging cells in zebrafish embryos with extensive data on which genes are switched on and off as individual cells navigate to their eventual stations and "decide" what role they will ultimately play in the body of the adult fish.

A freshwater species native to South Asia, zebrafish as adults rarely exceed two inches in length, and they are a long-established model for developmental research relevant to human health.

About 70% of human genes have counterparts in zebrafish and, though we look quite different, as fellow vertebrates we share most of the same overall body plan in addition to the cellular and molecular processes by which various body parts initially form.

Critically, zebrafish embryos are also mostly transparent and—unlike those of, say, mice—develop outside the mother, making it possible for scientists to observe their early growth in detail under a microscope.

Creating Zebrahub, which is free to all and includes built-in analytical tools designed for biologists, required building a suite of new instruments and software. It's the most comprehensive atlas of its kind and, as the researchers write in the paper, an important step towards "ushering in a new era for developmental and evolutionary biology."

"How a lifeform goes from a single cell to an entire body is one of biology's biggest mysteries," said senior author Loïc Royer, leader of the Organismal Architecture group and director of imaging AI at CZ Biohub SF. "With Zebrahub, we've created possibly the most detailed map of that process ever."

A zebrafish embryo at 20 hours of development, captured with a light-sheet microscope designed and built at CZ Biohub San Francisco. Credit: CZ Biohub San Francisco

The complexity of life

To form a complex adult organism such as a human or fish, a fertilized egg must split into a set of progeny that continue dividing until millions of cells have been born and have assumed their roles as parts of the skin, liver, brain, and all the other components of the body.

While, for the most part, all cells of an embryo contain an identical set of genes, the way that each type of cell uses these genes—switching them on and off in different combinations at different timepoints—is unique.

Scientists have long pondered just how the "choices" regarding thousands of genes in millions of cells come together to create a fully functioning adult lifeform with many types of specialized tissues. Each advancement towards solving this daunting puzzle yields new insights about why the process sometimes goes wrong, leading to disorders and disease.

But even with powerful models like zebrafish, developmental biology has historically been conducted in a piecemeal fashion, limited by the complexity of examining events far too tiny to see, and happening by the millions across the bodies of fragile living organisms that can be easily damaged by the very experiments designed to understand them.

As in the early days of cartography—before satellites snapped pictures of Earth from space and cars with spinning cameras mapped our streets—the field has made its breakthroughs in fits and starts, and has lacked a comprehensive system for considering the whole instead of just the pieces.

With Zebrahub, researchers at CZ Biohub SF hope to help change that, accelerating the field by giving researchers easy access to the breadth of these processes, all in one place.

Thanks to a new set of laboratory procedures developed at CZ Biohub SF, Zebrahub is also one of the first datasets of its kind to include gene expression data specific to individual embryos, as the process of collecting such data has typically required researchers to pool DNA from multiple embryos together.

This means Zebrahub confers the added benefit of allowing scientists to investigate the subtle expression differences that might give rise to different health outcomes among sibling fish.

"Zebrahub offers one of the first opportunities to investigate the behavior of cells in the extremely complex process of development with extremely high precision," says Merlin Lange, a CZ Biohub SF senior staff scientist and first author of the new Cell paper. "It's very rare to combine both gene expression from individual cells and spatial mapping of cells over time in the same resource like this."

This color-coded data visualization helps scientists understand how gene expression changes across thousands of developing cells at once. As cells change their identity — measured by which genes are switching on or off at any given moment — they move into different parts of the map representing different types of tissue within an embryo. Credit: Lange et al., Cell, 2024

Details in motion

Zebrahub features two major datasets, along with a suite of tools designed to help biologists use them. The first offers time-lapse video microscopy showing the birth and early movements of most cells in a zebrafish embryo in the first 24 hours after fertilization, during which time organs start to form. The second provides data on which genes were active in more than 120,000 zebrafish cells at 10 separate time points during the embryos' first 10 days.

To create the time-lapse videos, Royer, Lange, and CZ Biohub SF scientists and engineers designed and built "DaXi" (pronounced "dah-shee"), a new kind of automated microscope with a field of view large enough to capture images of entire living embryos.

DaXi is a so-called light-sheet microscope that emits and captures light in a unique way designed to protect embryos from high-intensity laser beams that would damage or even kill the embryo after a short period of time.

Then, to allow scientists to easily use the captured videos to study specific cells, CZ Biohub SF software engineer Jordão Bragantini led the development of a sophisticated new program called Ultrack, which automatically identifies cell nuclei (typically the most distinctive landmark in a cell) and tracks their movements in the videos over time in three-dimensional space.

Combined, the datasets generated by these tools allow researchers to conduct "virtual experiments" examining where cells begin and end up during development—even running their developmental trajectory backward and forward in time.

In just developing this methodology, the Zebrahub team has already made some intriguing discoveries. For example, the team looked at a subset of cells in the embryo's tail called neuro-mesodermal progenitors, which, at the timepoints they examined, had previously been thought to only be able to give rise to one type of tissue.

However, as the Zebrahub researchers analyzed the cells' movement and expansion, they realized these cells were actually developing into both muscle cells and neurons that were integrating into the spinal cord.

Ultrack, a sophisticated new program from CZ Biohub SF, automatically tracks an embryo's rapidly multiplying cell population as cells divide, migrate, and develop into their final states. Credit: Lange et al., Cell, 2024

"This was a very unexpected finding," Lange said. "And it's the kind of thing that would be hard to confirm without the broad view that Zebrahub provides."

Zebrahub, which has been available online to researchers for just over a year, has already helped support discoveries from other labs. One team that included researchers from Ashland University in Ohio and the State University of New York in Albany used Zebrahub in concert with their own cell atlas to ask which cellular proteins might contribute to the formation of cataracts in the eye.

For this, the researchers relied on Zebrahub's gene expression database to see when the cells of the lens activate and deactivate certain genes in a way that might lead to problems.

"Zebrafish are really small, and it's really difficult for us to peel the lens apart in order to ask questions about what genes are working in this region and how one cell might be different from another," said Mason Posner, a professor of biology at Ashland and co-senior author of the study. Here, "that's already been done for us and we can get these deep understandings about, for example, how this tissue even becomes transparent and functions, essentially, as biological glass."

A project five years in the making, Zebrahub required the development of numerous new technologies to achieve and relied on experts in the fields of biology, engineering, optics, physics, and data science housed under the roof of CZ Biohub SF. Every piece of technology developed in the process is open-source, which will contribute to more data being added to the project as the community works together to improve our view of embryo development.

by Chan Zuckerberg Biohub

Source: Zebrahub: New atlas tracks zebrafish development like never before

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Source: Beetlejuice Beetlejuice (2024) - Photos - IMDb

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Beetlejuice Beetlejuice Behind the Scenes | Til Death Do We Park | Warner Bros. Entertainment

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Funny and Weird Clips (3423)

Friday, November 1, 2024

NASA, NOAA Rank 2024 Ozone Hole as 7th-Smallest Since Recovery Began - EARTH

Healing continues in the atmosphere over the Antarctic: a hole that opens annually in the ozone layer over Earth’s southern pole was relatively small in 2024 compared to other years. Scientists with NASA and the National Oceanic and Atmospheric Administration (NOAA) project the ozone layer could fully recover by 2066.

This map shows the size and shape of the ozone hole over the South Pole on Sept. 28, 2024, the day of its annual maximum extent, as calculated by the NASA Ozone Watch team. Scientists describe the ozone “hole” as the area in which ozone concentrations drop below the historical threshold of 220 Dobson units.

During the peak of ozone depletion season from Sept. 7 through Oct. 13, the 2024 area of the ozone hole ranked the seventh smallest since recovery began in 1992, when the Montreal Protocol, a landmark international agreement to phase out ozone-depleting chemicals, began to take effect.

At almost 8 million square miles (20 million square kilometers), the monthly average ozone-depleted region in the Antarctic this year was nearly three times the size of the contiguous U.S. The hole reached its greatest one-day extent for the year on Sept. 28 at 8.5 million square miles (22.4 million square kilometers).

The improvement is due to a combination of continuing declines in harmful chlorofluorocarbon (CFC) chemicals, along with an unexpected infusion of ozone carried by air currents from north of the Antarctic, scientists said.

The ozone hole over Antarctica averaged nearly 8 million square miles (20 million square kilometers) between Sept. 7 and Oct. 13, 2024, the 20th smallest extent in 45 years.
Credit: NASA’s Goddard Space Flight Center/ Kathleen Gaeta

In previous years, NASA and NOAA have reported the ozone hole ranking using a time frame dating back to 1979, when scientists began tracking Antarctic ozone levels with satellite data. Using that longer record, this year’s hole ranked 20th smallest in area across the 45 years of observations.

“The 2024 Antarctic hole is smaller than ozone holes seen in the early 2000s,” said Paul Newman, leader of NASA’s ozone research team and chief scientist for Earth sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The gradual improvement we’ve seen in the past two decades shows that international efforts that curbed ozone-destroying chemicals are working.”

The ozone-rich layer high in the atmosphere acts as a planetary sunscreen that helps shield us from harmful ultraviolet (UV) radiation from the Sun. Areas with depleted ozone allow more UV radiation, resulting in increased cases of skin cancer and cataracts. Excessive exposure to UV light can also reduce agricultural yields as well as damage aquatic plants and animals in vital ecosystems.

Scientists were alarmed in the 1970s at the prospect that CFCs could eat away at atmospheric ozone. By the mid-1980s, the ozone layer had been depleted so much that a broad swath of the Antarctic stratosphere was essentially devoid of ozone by early October each year. Sources of damaging CFCs included coolants in refrigerators and air conditioners, as well as aerosols in hairspray, antiperspirant, and spray paint. Harmful chemicals were also released in the manufacture of insulating foams and as components of industrial fire suppression systems.

The Montreal Protocol was signed in 1987 to phase out CFC-based products and processes. Countries worldwide agreed to replace the chemicals with more environmentally friendly alternatives by 2010. The release of CFC compounds has dramatically decreased following the Montreal Protocol. But CFCs already in the air will take many decades to break down. As existing CFC levels gradually decline, ozone in the upper atmosphere will rebound globally, and ozone holes will shrink.

Ozone 101 is the first in a series of explainer videos outlining the fundamentals of popular Earth science topics. Let’s back up to the basics and understand what caused the Ozone Hole, its effects on the planet, and what scientists predict will happen in future decades.
Credit: NASA’s Goddard Space Flight Center/ Kathleen Gaeta

“For 2024, we can see that the ozone hole’s severity is below average compared to other years in the past three decades, but the ozone layer is still far from being fully healed,” said Stephen Montzka, senior scientist of the NOAA Global Monitoring Laboratory.

Researchers rely on a combination of systems to monitor the ozone layer. They include instruments on NASA’s Aura satellite, the NOAA-20 and NOAA-21 satellites, and the Suomi National Polar-orbiting Partnership satellite, jointly operated by NASA and NOAA.

NOAA scientists also release instrumented weather balloons from the South Pole Baseline Atmospheric Observatory to observe ozone concentrations directly overhead in a measurement called Dobson Units. The 2024 concentration reached its lowest value of 109 Dobson Units on October 5. The lowest value ever recorded over the South Pole was 92 Dobson Units in October 2006.

NASA and NOAA satellite observations of ozone concentrations cover the entire ozone hole, which can produce a slightly smaller value for the lowest Dobson Unit measurement.

“That is well below the 225 Dobson Units that was typical of the ozone cover above the Antarctic in 1979,” said NOAA research chemist Bryan Johnson. “So, there’s still a long way to go before atmospheric ozone is back to the levels before the advent of widespread CFC pollution.”

View the latest status of the ozone layer over the Antarctic with NASA’s ozone watch.

By James Riordon
NASA’s Earth Science News Team

Source: NASA, NOAA Rank 2024 Ozone Hole as 7th-Smallest Since Recovery Began - NASA

Smart sensor patch detects health symptoms through edge computing

The sensor patch is connected to a processor (circuit) that includes a Bluetooth module and is powered by a battery. The Bluetooth module allows the sensor patch to be linked to a phone to record data. Credit: Guren Matsumura, et al. Device. October 21, 2024

Edge computing on a smartphone has been used to analyze data collected by a multimodal flexible wearable sensor patch and detect arrhythmia, coughs and falls.

Wearable sensors are devices that can be worn on the body and measure the state of the body. They are part of the Internet of Things (IoT) and show great promise for monitoring health. These sensors generate large amounts of data, and that data must be processed to be understood.

The field of computing dealing with processing these data on the sensor or a device that the sensor is connected to—rather than at a remote server on the cloud—is called edge computing. Edge computing is a key element in wearable sensor technology.

A research team from Japan, led by Professor Kuniharu Takei at Hokkaido University and Associate Professor Kohei Nakajima at The University of Tokyo, have fabricated a flexible multimodal wearable sensor patch and developed edge computing software that is capable of detecting arrhythmia, coughs and falls in volunteers.

The sensor, which uses a smartphone as the edge computing device, was described in a paper published in the journal Device.

"Our goal in this study was to design a multimodal sensor patch that could process and interpret data using edge computing, and detect early stages of disease during daily life," explains Takei.

A demonstration of how the newly developed smart sensor patch is paired to a phone to detect changes in various parameters, as well as conditions such as arrhythmia, coughs and falls. Credit: Guren Matsumura, et al. Device. October 21, 2024

The team fabricated sensors that monitor cardiac activity via electrocardiogram (ECG), respiration, skin temperature, and humidity caused by perspiration. After confirming their suitability for long-term use, the sensors were integrated onto a flexible film (sensor patch) that adheres to human skin. The sensor patch also included a Bluetooth module to connect to a smartphone.

The team first tested the capability of the sensor patch to detect physiological changes in three volunteers, who wore it on their chests. The sensor patch was used to monitor vital signs in the volunteers under wet-bulb globe temperatures (used to determine likelihood of heat stress) of 22°C and over 29°C.

"Although our test group was small, we could observe their vital signs change during time-series monitoring at high temperatures. This observation may eventually lead to the identifying symptoms of early-stage heat stress," Takei explains.

The smart sensor patch is fabricated on a supporting film so that it may be peeled off and stuck onto the skin. Credit: Guren Matsumura, et al. Device. October 21, 2024

The team developed a machine learning program to process the recorded data to detect other symptoms such as heart arrhythmia, coughing and falls. "In addition to performing the analysis on a computer," Nakajima says, "we also designed an edge computing application for smartphones that could perform the same analysis. We achieved prediction accuracy of over 80%."

"The significant advance of this study is the integration of multimodal flexible sensors, real-time machine learning data analyses, and remote vital monitoring using a smartphone," Takei concludes.

"One drawback of our system is that training could not be carried out on the smartphone, and had to be done on the computer; however, this can be solved by simplifying the data processing." This study advances the concept of a patched-based, edge-computing system for telemedicine or telediagnosis.

by Hokkaido University

Source: Smart sensor patch detects health symptoms through edge computing