Expansion of universe directly impacts black hole growth

First rendered image of a black hole, illuminated by infalling matter
(Image credit: Jean-Pierre Luminet)

Over the past 6 years, gravitational wave observatories have been detecting black hole mergers, verifying a major prediction of Albert Einstein’s theory of gravity. But there is a problem—many of these black holes are unexpectedly large. Now, a team of researchers from the University of Hawaiʻi at Mānoa, the University of Chicago, and the University of Michigan at Ann Arbor, have proposed a novel solution to this problem: black holes grow along with the expansion of the universe.

Since the first observation of merging black holes by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015, astronomers have been repeatedly surprised by their large masses. Though they emit no light, black hole mergers are observed through their emission of gravitational waves—ripples in the fabric of spacetime that were predicted by Einstein’s theory of general relativity. Physicists originally expected that black holes would have masses less than about 40 times that of the Sun, because merging black holes arise from massive stars, which can’t hold themselves together if they get too big.

Comparison of black hole merger observations with predictions from the new model. The horizontal axis shows the total mass of both black holes in any individual merger, relative to the Sun’s mass.

The LIGO and Virgo observatories, however, have found many black holes with masses greater than that of 50 suns, with some as massive as 100 suns. Numerous formation scenarios have been proposed to produce such large black holes, but no single scenario has been able to explain the diversity of black hole mergers observed so far, and there is no agreement on which combination of formation scenarios is physically viable. This new study, published in the Astrophysical Journal Letters, is the first to show that both large and small black hole masses can result from a single pathway, wherein the black holes gain mass from the expansion of the universe itself.

1,800-plus ‘young’ volcanoes in the U.S. Southwest

The peaks of monogenetic volcanoes,
viewed across Lunar Lake in Nevada.
Credit: Greg Valentine

They’re born. They live once, erupting for a period that might last for days, years or decades. Then, they go dark and die.

This narrative describes the life of a monogenetic volcano, a type of volcanic hazard that can pose important dangers despite an ephemeral existence.

The landscape of the southwestern U.S. is heavily scarred by past eruptions of such volcanoes, and a new study marks a step toward understanding future risks for the region.

The research, which will be published on Nov. 2 in the journal Geosphere, provides a broad overview of what we know — and don’t know — about this type of volcanism in the U.S. Southwest over the past 2.58 million years, a geologic period known as the Quaternary.

During this time, more than 1,800 monogenetic volcanoes erupted in the region, according to a count covering Nevada, Utah, Arizona, Colorado, New Mexico and parts of California’s eastern edge. Add in the Pinacate volcanic field, located mostly in the Mexican state of Sonora, bordering Arizona, and the number goes up to over 2,200, scientists say. (The volcanoes included are ones whose ages are estimated to be in the range of the Quaternary, but many have not been precisely dated.)

“Monogenetic means ‘one life,’” says lead author Greg Valentine, a University at Buffalo volcanologist. “So a monogenetic volcano will erupt once, and that eruption may last for several days to several decades, but after that, the volcano is basically dead.

“In the United States, most volcanic hazards-related attention has rightly gone to places like Hawaii, and to the Pacific Northwest and Alaska, where we have big stratovolcanoes like Mount Rainier and Mount St. Helens, which will have many eruptive episodes over a long life, with widespread hazardous effects. In the past, these smaller monogenetic volcanoes really haven’t been looked at from a focus on hazards; they have been instead studied mainly for what they tell us about the deep earth. Recently, however, there has been more buzz in the research community about how we need to take a look at the kinds of hazards these volcanoes might pose.

Far-reaching ecological change in the eastern Mediterranean

Tropical wing snail (Conomurex persicus),
an Indo-Pacific species, off the Israeli coast (© Jan Steger)

Different ecological niches: Tropical species are profoundly changing the way ecosystems in the eastern Mediterranean - with hardly any consequences

Communities of introduced tropical species differ significantly in their biological properties from the native wildlife in the eastern Mediterranean, as an international team of researchers led by Jan Steger from the Institute of Paleontology found. As a result - and due to the progressive collapse of Mediterranean species - the shallow water ecosystems in the region are changing particularly profoundly. The study was published in the journal Global Ecology and Biogeography.

The eastern Mediterranean is undergoing dramatic ecological change - while native species are disappearing more and more, tropical organisms introduced through the Suez Canal, called Lesseps’s species, thrive splendidly as a result of ever warmer water temperatures. However, they do not directly displace the native species, but rather occupy "free niches", according to a study that has now been published in the Journal Global Ecology and Biogeography.

"To understand how the increase in tropical species affects the native fauna and the function of the ecosystems, one has to compare their biological properties - such as lifestyle or nutrition - with those of the native fauna," says Jan Steger, doctoral student and first author of the new one Study.

Laser Mapping in Southern Mexico Discovers Nearly 500 Ancient Sites

Using laser mapping data, researchers from The University of Texas at Austin and other national and international institutions have discovered 478 ancient ceremonial centers in southern Mexico. Most of the sites probably date to 1100-400 B.C., several centuries before the Classic Age (A.D. 250-950) of Maya civilization.

The findings, published in Nature Human Behavior, further scholars’ understanding of the origins of Mesoamerican civilizations, particularly about the relationship between Olmec and Maya cultures. The newly found sites demonstrate the influence of Olmec architectural innovations on Maya centers of the Classic Age and broaden our knowledge of how the Olmec civilization transformed their environment through agriculture.

Lidar (Light Detection and Ranging) is a technology that can penetrate vegetation to map three-dimensional forms of the ground and archaeological sites. This study used publicly available lidar data obtained by the Instituto Nacional de Estadística y Geografía (INEGI), a Mexican governmental organization. It covered an area of 85,000 square kilometers, equivalent to the island of Ireland, representing the largest archaeological lidar study of Mesoamerica.

The hundreds of newly identified rectangular and square complexes show highly standardized formats and were probably the earliest material expressions of basic concepts of Mesoamerican calendars and a number system.

“These cultural centers showed remarkable regularity in sizes and orientation along cardinal directions and were a landscape manifestation of the essential concepts of the Maya calendars and number system,” said study co-author Timothy Beach, a professor in the Department of Geography and the Environment at UT Austin. “Mesoamerican belief and knowledge systems are apparent in the landscapes they terraformed.”

Department of Energy to Provide $10 Million for Climate and Earth System Modeling Research

Today, the U.S. Department of Energy  announced plans to provide $10 million for new grants to universities, other academic institutions, non-profit organizations, for profit organizations, and other federal agencies within the area of Earth and environmental systems modeling research. Grants will focus on two related areas of research: further development of DOE’s flagship Energy Exascale Earth System Model (E3SM), with a particular emphasis on improving the accuracy of low level cloud representations; and studies that improve the predictive understanding of the climate variability, water cycle and related hydrological extremes.

Specific topics solicited in modeling research vary from year to year to enhance and take advantage of new modeling capabilities and emerging challenges facing the community. For this Funding Opportunity Announcement, grants will be strongly encouraged to emphasize high resolution, process-level, scientific understanding that advances or leverages E3SM’s current capability such as the Simple Cloud-Resolving E3SM Atmosphere Model (SCREAM) and the innovative use of a hierarchy of models, multi-models, machine learning, and metrics to reduce prediction uncertainty.

“Climate prediction research has evolved to become a national imperative, given that the trend towards increasing climate-induced risks to people, property, and infrastructure requires concerted action and climate solutions,” said Sharlene Weatherwax, DOE Associate Director for Biological and Environmental Research. “These grants will ensure a strengthened science base for making more accurate predictions of climate change that must be well understood before making informed decisions.”

The Department anticipates that $10 million will be available for this program in Fiscal Year 2022. Funding is to be awarded competitively, on the basis of peer review, and is expected to be in the form of three-year grants with total award amounts ranging from $600,000 to $900,000.

More information on the Office of Biological and Environmental Research (BER) can be found here. More information on the BER Earth and Environmental System Modeling program can be found here.

Source/Credit: U.S. Department of Energy

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Quadricep muscle contracts differently after ACL reconstruction

After an anterior cruciate ligament reconstruction surgery, it’s common to experience quadriceps weakness, which was thought to be caused primarily by muscle atrophy, or shrinkage.

But researchers at the University of Michigan School of Kinesiology have found an additional cause, which could help clinicians design more effective rehabilitation programs.

They found that besides muscle loss, the quadricep muscle—specifically, the fibers within that muscle—contract differently. Taken together, these deficits result in a muscle that is weaker and behaves like that of someone much older.

“This is the first human-based paper that is focused on proving that muscle is not just smaller after injury, but it also contracts differently,” said Lindsey Lepley, assistant professor and corresponding author on the study. “This is a key new discovery that helps explain the persistent weakness that is so commonly observed.”

Lepley said her group follows the aging literature and that many of the factors that plague aged muscle also emerge after ACL injury.

“Generally our group has been saying that an ACL injury prematurely ages the limb—the joint itself often shows signs of arthritis within 10 years and the muscle also exhibits factors like aged muscle tissue,” Lepley said.

ACL is a common musculoskeletal injury, with about 300,000 occurring annually in the United States. Yearly treatment costs exceed $2 billion.

Scientists identify new antibody for COVID-19 and variants

Megan May/UNC Research

A research collaboration between scientists at Duke University and the University of North Carolina at Chapel Hill has identified and tested an antibody that limits the severity of infections from a variety of coronaviruses, including those that cause COVID-19 as well as the original SARS illness.

The antibody was identified by a team at the Duke Human Vaccine Institute and tested in animal models at UNC-Chapel Hill. Researchers published their findings Nov. 2 in the journal Science Translational Medicine.

“This antibody has the potential to be a therapeutic for the current epidemic,” said co-senior author Dr. Barton Haynes, director of DHVI. “It could also be available for future outbreaks, if or when other coronaviruses jump from their natural animal hosts to humans.”

Haynes and colleagues at DHVI isolated the antibody by analyzing the blood from a patient who had been infected with the original SARS-CoV-1 virus, which caused the SARS outbreak in the early 2000s, and from a current COVID-19 patient.

They identified more than 1,700 antibodies, which the immune system produces to bind at specific sites on specific viruses to block the pathogen from infecting cells. When viruses mutate, many binding sites are altered or eliminated, leaving antibodies ineffectual. But there are often sites on the virus that remain unchanged despite mutations. The researchers focused on antibodies that target these sites because of their potential to be highly effective across different lineages of a virus.

Study Sheds Light on the Evolution of Underground Microbes

Calcite, a mineral related to the presence of microorganisms, was recovered from a deep fracture in Swedish granite. Reiners and Drake used mineral-related biosignatures such as these to look for ancient habitable conditions deep inside the Earth.Henrik Drake/Linnaeus University

A new study sheds light on the evolutionary history of what might be the most elusive form of life on Earth: the deep biosphere – a hidden realm of microbes inhabiting the upper few kilometers of Earth's crust.

Calcite, a mineral related to the presence of microorganisms, was recovered from a deep fracture in Swedish granite. Reiners and Drake used mineral-related biosignatures such as these to look for ancient habitable conditions deep inside the Earth. Henrik Drake/Linnaeus University

Deep, dark fractures reaching far down into the oldest rocks on Earth may seem about as hospitable to life as outer space, but some estimates suggest that microbes dwelling deep in the Earth's crust account for the majority of microbial life. These underground lifeforms, which make up what's known as the deep biosphere, could account for as much as 20% of all biomass on Earth.

These ecosystems host microbial lineages that are of interest for understanding the origin and evolution of life on our planet but remain the least explored and understood ecosystems on Earth, according to the authors of a new study that takes a closer look at how deep habitats changed during Earth's tumultuous past.

1.5°C temperature rise can cause significant changes in coastal species

Marine species on exposed rocks in Bude, Cornwall

A temperature increase of around 1.5°C – just under the maximum target agreed at the COP23 Paris meeting in 2017 – can have a marked impact on algae and animal species living on UK coastlines, new research has found.

The study, by ecologists at the University of Plymouth, examined how increases in rock surface temperature were affecting the quantity and behavior of species commonly found on the shorelines of Devon and Cornwall.

It focused on two sites on the region’s north coast (at Bude and Croyde) and two on the south coast (Bantham and South Milton Sands), all of which have deep gullies with both north-facing and south-facing surfaces.

Their findings showed the average annual temperature on the south-facing surfaces at low tide was 1.6°C higher than those facing north and that temperature extremes (i.e. > 30°C) were six-fold more frequent on south-facing aspects.

Across the four sites, these differences had a significant effect on species abundance with 45 different species found on north-facing sites during the summer of 2018 compared to 30 on south-facing ones.

In winter, the figures were 42 and 24 respectively, while some species – including the red seaweed Plumaria plumosa and sea cauliflower (Leathesia marina) – were restricted to north-facing surfaces.

The different temperatures also had an impact on species’ breeding patterns with five times more dog whelk (Nucella lapillus) eggs found on north-facing surfaces than south-facing ones.

Poor water quality and trawling take toll on seagrass

Ecosystems under the sea, such as seagrass, cannot be easily observed like forests or prairies on the land.

A team of researchers led by Griffith University used data from the places where seagrass trends have been assessed to calculate for all the world’s oceans where risks to this ecosystem are greatest.

This will help to target monitoring geographically and ultimately focus conservation actions where they are most needed.

The researchers found that poor water quality and destructive fisheries practices such as trawling are contributing to the global decline of seagrass meadows, which are vital habitats and food sources for marine species and act as climate regulators.

Published in PNAS, researchers from the Australian Rivers Institute and Coastal and Marine Research Centre modelled the trajectories of seagrass meadows in response to anthropogenic pressures at 395 sites around the world between 2000 and 2010.

Seagrass meadows off Australian coastlines were among these sites, where meadows ranged from being increasing to rapidly declining.

The authors assessed the impacts of eight factors and predicted the regions at greatest risk of seagrass meadow decline. The results suggest that water quality and destructive trawl and dredge fishing had the strongest associations with rapid seagrass meadow decline.