NASA’s SPHEREx Observatory Completes First Cosmic Map Like No Other - UNIVERSE

 

This panoramic view of SPHEREx’s first all-sky map shows how the sky looks to the telescope. It transitions between observations of colors emitted by hot hydrogen gas (blue) and cosmic dust (red), and those primarily emitted by stars.
Credit: NASA/JPL-Caltech

Launched in March, NASA’s SPHEREx space telescope has completed its first infrared map of the entire sky in 102 colors. While not visible to the human eye, these 102 infrared wavelengths of light are prevalent in the cosmos, and observing the entire sky this way enables scientists to answer big questions, including how a dramatic event that occurred in the first billionth of a trillionth of a trillionth of a second after the big bang influenced the 3D distribution of hundreds of millions of galaxies in our universe. In addition, scientists will use the data to study how galaxies have changed over the universe’s nearly 14 billion-year history and learn about the distribution of key ingredients for life in our own galaxy.  

“It’s incredible how much information SPHEREx has collected in just six months — information that will be especially valuable when used alongside our other missions’ data to better understand our universe,” said Shawn Domagal-Goldman, director of the Astrophysics Division at NASA Headquarters in Washington. “We essentially have 102 new maps of the entire sky, each one in a different wavelength and containing unique information about the objects it sees. I think every astronomer is going to find something of value here, as NASA’s missions enable the world to answer fundamental questions about how the universe got its start, and how it changed to eventually create a home for us in it.” 

Circling Earth about 14½ times a day, SPHEREx (which stands for Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) travels from north to south, passing over the poles. Each day it takes about 3,600 images along one circular strip of the sky, and as the days pass and the planet moves around the Sun, SPHEREx’s field of view shifts as well. After six months, the observatory has looked out into space in every direction, capturing the entire sky in 360 degrees. 

Managed by NASA’s Jet Propulsion Laboratory in Southern California, the mission began mapping the sky in May and completed its first all-sky mosaic in December. It will complete three additional all-sky scans during its two-year primary mission, and merging those maps together will increase the sensitivity of the measurements. The entire dataset is freely available to scientists and the public.  

“SPHEREx is a mid-sized astrophysics mission delivering big science,” said JPL Director Dave Gallagher. “It’s a phenomenal example of how we turn bold ideas into reality, and in doing so, unlock enormous potential for discovery.”  

Superpowered telescope 

Each of the 102 colors detected by SPHEREx represents a wavelength of infrared light, and each wavelength provides unique information about the galaxies, stars, planet-forming regions, and other cosmic features therein. For example, dense clouds of dust in our galaxy where stars and planets form radiate brightly in certain wavelengths but emit no light (and are therefore totally invisible) in others. The process of separating the light from a source into its component wavelengths is called spectroscopy.  

And while a handful of previous missions has also mapped the entire sky, such as NASA’s Wide-field Infrared Survey Explorer, none have done so in nearly as many colors as SPHEREx. By contrast, NASA’s James Webb Space Telescope can do spectroscopy with significantly more wavelengths of light than SPHEREx, but with a field of view thousands of times smaller. The combination of colors and such a wide field of view is why SPHEREx is so powerful. 

“The superpower of SPHEREx is that it captures the whole sky in 102 colors about every six months. That’s an amazing amount of information to gather in a short amount of time,” said Beth Fabinsky, the SPHEREx project manager at JPL. “I think this makes us the mantis shrimp of telescopes, because we have an amazing multicolor visual detection system and we can also see a very wide swath of our surroundings.” 

To accomplish this feat, SPHEREx uses six detectors, each paired with a specially designed filter that contains a gradient of 17 colors. That means every image taken with those six detectors contains 102 colors (six times 17). It also means that every all-sky map that SPHEREx produces is really 102 maps, each in a different color.  

The observatory will use those colors to measure the distance to hundreds of millions of galaxies. Though the positions of most of those galaxies have already been mapped in two dimensions by other observatories, SPHEREx’s map will be in 3D, enabling scientists to measure subtle variations in the way galaxies are clustered and distributed across the universe.  

Each frame of this movie shows the entire sky in a different infrared wavelength, indicated by the color bar in the top right corner. Taken by NASA’s SPHEREx observatory, the maps illustrate how viewing the universe in different wavelengths of light can reveal unique cosmic features.
Credit: NASA/JPL-Caltech

Those measurements will offer insights into an event that took place in the first billionth of a trillionth of a trillionth of a second after the big bang. In this moment, called inflation, the universe expanded by a trillion-trillionfold. Nothing like it has occurred in the universe since, and scientists want to understand it better. The SPHEREx mission’s approach is one way to help in that effort. 

More about SPHEREx 

The SPHEREx mission is managed by JPL for NASA’s Astrophysics Division within the Science Mission Directorate in Washington. The telescope and the spacecraft bus were built by BAE Systems. The science analysis of the SPHEREx data is being conducted by a team of scientists at 10 institutions across the U.S., and in South Korea and Taiwan. Data is processed and archived at IPAC at Caltech in Pasadena, which manages JPL for NASA. The mission’s principal investigator is based at Caltech with a joint JPL appointment. The SPHEREx dataset is publicly available. 

For more information about the SPHEREx mission visit: https://science.nasa.gov/mission/spherex/ 

Source: NASA’s SPHEREx Observatory Completes First Cosmic Map Like No Other - NASA

How gut bacteria could help to diagnose teen depression - Psychology & Psychiatry - Gastroenterology

Image generated by the editorial team using DALL·E for illustrative purposes.

Major depressive disorder (MDD) is a debilitating psychiatric condition characterized by a persistently low mood, a lack of motivation, feelings of hopelessness, altered sleeping and/or eating patterns, and a reduced interest in everyday activities.

All these symptoms typically make it very difficult for affected individuals to complete daily tasks, connect with others and engage in other activities that would normally contribute to their well-being.

Past studies estimate that about half of patients diagnosed with MDD experience the first symptoms of the disorder during adolescence, the critical stage of development between childhood and adulthood. Adolescence can be a very confusing and challenging time for many humans, as it is a period marked by rapid and yet profound changes affecting both the brain and body.

While the incidence of early depressive episodes during teenage years is now well-documented, diagnosing the disorder is not always easy. Currently, psychiatrists, psychologists and general health practitioners predominantly diagnose MDD via clinical interviews or self-reported questionnaires, rather than biological or medical tests.

Researchers at the Psychiatric Center of Chongqing Medical University and other institutes in China have identified new biomarkers of MDD in adolescence, by specifically looking at the microorganisms and bacteria within the digestive system.

Their paper, published in Translational Psychiatry, offers new insight into the gut microbiota that are more prevalent in teenagers diagnosed with depression than in adolescents with no mental health disorders. 

Graphical summary of study participants and the sample collection process. Credit: Liu et al.

"Despite its high prevalence and impact, objective diagnostic biomarkers for adolescent MDD remain limited, particularly those related to gut microbiota," write Xueer Liu, Aoyi Geng and their colleagues. "Our study examined potential co-diagnostic biomarkers from peripheral blood and fecal samples in adolescents with MDD."

Probing the link between mind and gut

To carry out the study, the researchers recruited 46 adolescents who were experiencing their first episode of MDD and were less than 19 years old, along with 44 teenagers in the same age group who were not diagnosed with any mental health disorders. They collected both blood and stool samples from all these participants and analyzed them via standard laboratory procedures.

The blood samples were spun in a centrifuge to separate plasma (i.e., liquid part of blood) from cells, then analyzed to derive gut barrier proteins present in the samples and identify any markers of inflammation. The stool samples, on the other hand, were analyzed using genetics and microbiome analysis tools, to identify the DNA in gut bacteria, as well as the abundance of different microorganisms and overall microbiome diversity.

"We enrolled drug-naive adolescents with first-episode MDD and age-/sex-matched healthy controls," write the authors.

"The levels of tight junction proteins (Claudin-5, Zonulin, FABP) and inflammatory biomarkers (IL-6, IL-8, TNF-α, and CRP) were markedly elevated in the plasma of adolescents with MDD, indicating gut barrier dysfunction and systemic inflammation. The microbiome in MDD patients exhibited a lower Firmicutes-to-Bacteroidetes ratio. At the genus level, Intestinimonas and Barnesiella were significantly enriched, while Dialister and Collinsella were considerably reduced."

The researchers analyzed all the data they collected using statistical methods and were able to identify common patterns in the gut microbiome of healthy participants and those diagnosed with MDD. Firstly, they observed that adolescents with depression exhibited signs of weakened gut barriers and greater inflammation in their blood.

The composition of their gut bacteria was also different compared to that of teens with no psychiatric disorders. The team observed a lower balance of bacteria in the gut of teens with MDD, as well as a prevalence of a bacterium known as Collinsella, which was linked to inflammation and changes in the gut's barrier.

Informing the future diagnosis and treatment of depression

As part of their study, the researchers also explored the possibility of diagnosing MDD using the blood and stool markers they identified. They found that looking at a combination of inflammation-related biomarkers and the abundance of the bacterium Collinsella allowed them to diagnose MDD with good accuracy.

"Integrating Collinsella abundance with tight junction proteins and inflammatory markers significantly improved diagnostic performance, achieving an area under the curve (AUC) of 0.964," write Liu, Geng and their colleagues.

"Moreover, Collinsella negatively correlated with sex, Claudin-5, and TNF-α. Claudin-5 was strongly associated with short-chain fatty acids (SCFAs)-related pathways, including alanine, aspartate, glutamate metabolism, D-glutamine and D-glutamate metabolism, and autophagy regulation. Treatment of Caco-2 cells with propionate and butyrate confirmed the regulatory effects of SCFAs on tight junction biomarkers."

Overall, the team's research suggests that changes in gut bacteria influence the production of SCFAs, small molecules that are produced when gut bacteria break down dietary fiber. These changes in turn impact the function of the gut barrier, potentially contributing to inflammation and to the emergence of depressive symptoms.

In the future, the inflammation and gut-related biomarkers identified by Liu, Geng and their colleagues could serve as more effective targets for the reliable diagnosis of MDD in adolescents. In addition, their work could potentially contribute to the identification of new strategies aimed at reducing the intensity of depressive symptoms by altering the gut microbiome.

"These findings suggest the interplay between gut dysbiosis, barrier dysfunction, and inflammation in adolescent MDD and support microbiota-host biomarkers as a promising strategy for improving MDD diagnostic precision," write the authors. 

by Ingrid Fadelli, Medical Xpress

edited by Sadie Harley, reviewed by Robert Egan 

Source: How gut bacteria could help to diagnose teen depression