Connect with us

Biotech

New Research Questions ‘whiff of Oxygen’ in Earth’s Early History

Published

on

HANOVER, N.H. – January 5, 2022 – Evidence arguing for a “whiff of oxygen” before the Earth’s Great Oxygenation Event 2.3 billion years ago are chemical signatures that were probably introduced at a much later time, according to research published in Science Advances.

HANOVER, N.H. – January 5, 2022 – Evidence arguing for a “whiff of oxygen” before the Earth’s Great Oxygenation Event 2.3 billion years ago are chemical signatures that were probably introduced at a much later time, according to research published in Science Advances.

The result rewinds previous research findings that atmospheric oxygen existed prior to the so-called Great Oxygenation Event–known to researchers as “GOE”– and has the potential to rewrite what is known of the planet’s past.

“Without the whiff of oxygen reported by a series of earlier studies, the scientific community needs to critically reevaluate its understanding of the first half of Earth’s history,” said Sarah Slotznick, an assistant professor of earth sciences at Dartmouth and first author of the study.

The study indicates that the chemical data originally determined to suggest atmospheric oxygen earlier in Earth’s history may have been introduced by events hundreds of millions of years later.

Additional analysis conducted as part of the study reconfirms that Earth’s atmosphere featured exceedingly low oxygen levels prior to 2.3 billion years ago.

“We used new tools to investigate the origins of the signals of trace oxygen,” said Jena Johnson, an assistant professor of earth and environmental sciences at the University of Michigan and co-author of the study. “We found that a series of changes after the sediments were deposited on the seafloor were likely responsible for the chemical evidence of oxygen.”

The Initiation of Oxygenation
For decades, scientists have debated when measurable levels of oxygen first appeared in Earth’s atmosphere. The idea of the Great Oxygenation Event has developed over the last century and is thought to be when oxygen levels began to increase over 2 billion years ago, paving the way for the rise of complex cells, animals, and eventually humans.

More recently, however, research on chemical signals correlated to oxygen has suggested earlier transient appearances of oxygen, known as “whiffs.”

In 2007, two parallel studies found evidence of such a whiff of oxygen based on samples of the 2.5-billion-year-old Mount McRae Shale, part of a heavily studied 2004 drill core collected in Western Australia by the NASA Astrobiology Drilling Program.

“When the results came out a decade ago, they were startling,” said Joseph Kirschvink, professor of geobiology at Caltech, a member of the Earth-Life Science Institute at the Tokyo Institute of Technology, and a co-author of the new study. “The findings seemed to contradict abundant evidence from other geological indicators that argued against the presence of free oxygen before the Great Oxygenation Event.”

A Research Origin Story 
The 2007 studies were based on evidence of oxidation and reduction of molybdenum and sulfur, two elements that are widely used to test for the presence of atmospheric oxygen since it cannot be measured directly in rock. The findings raised fundamental questions about the early evolution of life on Earth.

The observation of early oxygen was taken by some research groups to support earlier findings that microscopic cyanobacteria—early innovators in photosynthesis—pumped oxygen into the ancient atmosphere but that other Earth processes kept oxygen levels low.

The 2007 studies, including their implications about the origin of life and its evolution, have been widely accepted and have served as the basis for a series of other research papers over the last 14 years.

The new study dates back to 2009, when a Caltech-led team began efforts to conduct additional analysis. The team, some of whom have since moved to other institutions, took over a decade to collect and analyze data, resulting now in the first published study that directly refutes the finding of a whiff of early oxygen.

“Rocks this old tell a complicated story that goes beyond what the world was like when the mud was deposited,” said Woodward Fischer, a professor of geobiology at Caltech and co-author of the study. “These samples also contain minerals that formed long after their deposition when ancient environmental signals were mixed with younger ones, confusing interpretations of the conditions on ancient Earth.”

A Matter of Approach
The 2007 research papers that found the whiff of oxygen prior to Earth’s full oxygenation used bulk analysis techniques featuring geochemical assessments of powdered samples sourced from throughout the Mount McRae Shale. Rather than conducting a chemical analysis on powder, the new research inspected specimens of the rock using a series of high-resolution techniques.

For the new study, the research team recorded images of the 2004 drill core on a flatbed optical scanner. Based on those observations, they then collected thin samples for additional analyses. The suite of approaches used on the physical specimens, including synchrotron-based X-ray fluorescence spectroscopy, gave the team additional insight into the geology and chemistry of the samples as well as the relative timing of processes that were identified.

According to the research paper: “Our collective observations suggest that the bulk chemical datasets pointing toward a ‘whiff’ of oxygen developed during post-depositional events.”

The new analysis shows that the Mount McRae Shale formed from organic carbon and volcanic dust. The research indicates that molybdenum came from volcanoes and subsequently concentrated during what has been previously characterized as the whiff interval. During a series of chemical and physical changes that turned these sediments into rock, fracturing created pathways for several distinct fluids to carry in signals of oxidation hundreds of millions of years after the rocks formed.

“Our observations of abundant pyroclastic glass shards and intercalated tuff beds, paired with the recent insight that volcanic glass is a major host of [molybdenum], offers a new explanation for the [molybdenum] enrichments in the ‘whiff’ interval,” the paper says.

Looking Back to Point a Way Forward
If the molybdenum was not from oxygen-based weathering of rocks on land and concentration in the ocean, its presence does not support the original finding of early atmospheric oxygen. By using a totally different methodology than that used in the first studies that found a whiff of oxygen, the new research also calls into question research that followed from those studies using the same style of bulk techniques.

“Our new, high-resolution data clearly indicates that the sedimentary context of chemical signals has to be carefully considered in all ancient records,” said Johnson.

In addition to providing an alternate explanation for oxygen proxies that were found in the Mount McRae Shale, the team confirmed that the level of atmospheric oxygen at the time before the Great Oxygenation Event was very low, calling it “negligible” in the approximate period 150 million years before the abrupt change.

The findings call into question the early existence of cyanobacteria, instead supporting other hypotheses that oxygen-generating photosynthesis evolved only shortly before the Great Oxygenation Event.

“We expect that our research will generate interest both from those studying Earth and those looking beyond at other planets,” said Slotznick. “We hope that it stimulates further conversation and thought about how we analyze chemical signatures in rocks that are billions of years old.”

Birger Rasmussen, of the University of Western Australia and China University of Geosciences; Timothy D. Raub, of the University of St Andrews and the Geoheritage Research Institute; Samuel Webb, of SLAC National Accelerator Laboratory; and Jian-Wei Zi, of the China University of Geosciences, all contributed to the study.

###

NOTES FOR EDITORS:

Original 2007 research papers suggesting a “whiff of oxygen”:

A. D. Anbar, Y. Duan, T.W. Lyons, G. L. Arnold, B. Kendall, R. A. Creaser, A. J. Kaufman, G. W. Gordon, C. Scott, J. Garvin, R. Buick, “A whiff of oxygen before the great oxidation event?” Science 317, 1903-1906 (2007).

A. J. Kaufman, D. T. Johnston, J. Farquhar, A. L. Masterson, T. W. Lyons, S. Bates, A. D. Anbar, G. L. Arnold, J. Garvin, R. Buick, “Late archean biospheric oxygenation and atmospheric evolution.” Science 317, 1900-1903 (2007).

Companion Dartmouth web story “Research Questions ‘Whiff of Oxygen’ on Ancient Earth” https://home.dartmouth.edu/news/2022/01/research-questions-whiff-oxygen-ancient-earth

For additional information and images: David Hirsch: [email protected]

Funding for this research came from the Agouron Institute, Packard Foundation, NASA, and the National Science Foundation.

A portion of the technical research was conducted at the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

About Dartmouth: Founded in 1769, Dartmouth is a member of the Ivy League and consistently ranks among the world’s greatest academic institutions. Dartmouth has forged a singular identity for combining its deep commitment to outstanding undergraduate liberal arts and graduate education with distinguished research and scholarship in the Arts and Sciences and its four leading graduate schools—the Geisel School of Medicine, the Guarini School of Graduate and Advanced Studies, Thayer School of Engineering, and the Tuck School of Business.

Read More

Article: bioengineer.org

Biotech

Are Researchers One Step Closer to Developing the Theory of Impulse Circuits?

Published

on

Computers play an important role in many aspects of life today. Digital computers are the most widely used, while quantum computers are well known. However, the least known computers are the so-called Stochastic Pulse Computers. Their work is based on highly parallel logical operations between trains of electrical pulses, where the pulses occur at random times, as in neurons, the nerve cells in the brains of humans and mammals.

Computers play an important role in many aspects of life today. Digital computers are the most widely used, while quantum computers are well known. However, the least known computers are the so-called Stochastic Pulse Computers. Their work is based on highly parallel logical operations between trains of electrical pulses, where the pulses occur at random times, as in neurons, the nerve cells in the brains of humans and mammals.

The main motivation for the growing interest in research on RPC computers over the past decade is the hope that they could solve faster and with less energy consumption tasks that are normally easy for living beings, but difficult for digital computers, such as instantaneous responses to stimuli, pattern recognition, robustness to errors and damage in the system, learning, and autonomy.

In a recent study published in Scientific Reports, researchers from the Croatian Centre of Excellence for Advanced Materials and Sensors, Dr Mario Stipčević of the Ruđer Bošković Institute (RBI) and Mateja Batelić, a student at the Faculty of Science at the University of Zagreb (FS), Croatia, describe new or improved versions of RPC circuits that use quantum randomness for the first time, but also go a significant step further and lay the first foundation for RPC circuit theory.

Namely, while circuits for processing information in a digital computer can be assembled from logic circuits as building blocks based on the well-known Boolean theory, a similar theory for RPC circuits does not yet exist. Therefore, the synthesis of circuits for an RPC is limited to trial and error through experimentation or simulation.

‘’The central part of our paper is the formulation and proof of the so-called entropy budget theorem, which can be used to easily verify whether a given mathematical (or logical) operation can be performed or “calculated” by any physical circuit, and if so, how much excess entropy must be available to a circuit in order to perform the given operation.

In this paper, we demonstrate the theorem using several examples of mathematical operations. Perhaps the most interesting proof is the existence of a deterministic half-sum circuit (a + b) / 2. However, this circuit is not yet known, and finding it is a challenge for further research,” says Mario Stipčević, head of the Laboratory of Photonics and Quantum Optics at the Ruđer Bošković Institute.

Feedzy

Source: bioengineer.org

Continue Reading

Biotech

PSMA PET Validates EAU Classification System to Determine Risk of Prostate Cancer Recurrence

Published

on

Reston, VA (January 20, 2022)—New research has confirmed the accuracy of the novel European Association of Urology (EAU) risk classification system that groups prostate cancer patients based on their risk of recurrence. Prostate-specific membrane antigen (PSMA) PET imaging of men with prostate cancer validated the EAU groupings and provided insights that could further refine risk assessment for patients. This study was published in the January issue of The Journal of Nuclear Medicine.

Credit: Justin Ferdinandus, Wolfgang P. Fendler, Andrea Farolfi, et al.

Reston, VA (January 20, 2022)—New research has confirmed the accuracy of the novel European Association of Urology (EAU) risk classification system that groups prostate cancer patients based on their risk of recurrence. Prostate-specific membrane antigen (PSMA) PET imaging of men with prostate cancer validated the EAU groupings and provided insights that could further refine risk assessment for patients. This study was published in the January issue of The Journal of Nuclear Medicine.

The diagnostic workup of prostate cancer has changed rapidly over the past few years. Recently, the EAU introduced a clinical system separating patients with rising PSA values after first-line therapy (prostate surgery or radiation) into groups of those with high risk and those with low risk for development of metastases. Shortly after this, the U.S. Food and Drug Administration approved 68Ga-PSMA-11 as the first PET drug to target the PSMA for men with prostate cancer.

“Given the growing availability of PSMA-directed PET imaging, our study sought to assess disease in patients based on the EAU classifications while using PSMA PET to identify subgroups of patients, such as those with undetectable, locoregional or distant metastatic disease,” said Justin Ferdinandus, MD, nuclear medicine physician at University Hospital in Essen, Germany.

The multicenter, international study analyzed PSMA PET scans of nearly 2,000 patients with prostate cancer and rising PSA levels. Patterns of disease spread on PSMA PET imaging were used to classify prostate cancer patients into both low- and high-risk groups. High-risk groups were found to have higher rates of metastatic disease on PSMA PET compared to low-risk groups. However, PSMA PET also found metastatic disease in low-risk and no disease in high-risk patients.

“Our study underscores the utility of the EAU risk groups to determine risk of metastasis in biochemically recurrent prostate cancer. But not every high-risk patient has metastases and not every low-risk patient has locoregional or no disease,” said Wolfgang Fendler, MD, nuclear medicine physician at University Hospital in Essen.

He continued, “The ultimate aim of imaging is to provide the right treatment for each patient. As evidenced in this research, the accuracy of PSMA PET is essential to improve stratification and potentially outcomes both in low-risk and high-risk settings.” 

The authors of “PSMA PET validates higher rates of metastatic disease for European Association of Urology Biochemical Recurrence Risk Groups: an international multicenter study” include Justin Ferdinandus, Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen, Essen, Germany; Wolfgang P. Fendler and Ken Hermann, Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen, Essen, Germany, and Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California; Andrea Farolfi, Department of Nuclear Medicine, University of Duisburg-Essen and German Cancer Consortium (DKTK)-University Hospital Essen, Essen, Germany, and Division of Nuclear Medicine, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; Samuel Washington, Department of Urology, University of California San Francisco, San Francisco, California, and Department of Epidemiology and Statistics, University of California San Francisco, San Francisco, California; Osama Mohamad, Department of Radiation Oncology, University of California San Francisco, San Francisco, California; Miguel H. Pampaloni and Thomas A. Hope, Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California; Peter J.H. Scott, Melissa Rodnick, Benjamin L. Viglianti and Morand Piert, Department of Radiology, University of Michigan, Ann Arbor, Michigan; Matthias Eiber, Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University Munich, Munich, Germany; and Johannes Czernin, Wesley R. Armstrong and Jeremie Calais, Ahmanson Translational Imaging Division, Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, California.

Visit JNM’s new website for the latest research, and follow our new Twitter and Facebook pages @JournalofNucMed.

###

Please visit the SNMMI Media Center for more information about molecular imaging and precision imaging. To schedule an interview with the researchers, please contact Rebecca Maxey at (703) 652-6772 or [email protected].
 

About JNM and the Society of Nuclear Medicine and Molecular Imaging
The Journal of Nuclear Medicine (JNM) is the world’s leading nuclear medicine, molecular imaging and theranostics journal, accessed more than 13 million times each year by practitioners around the globe, providing them with the information they need to advance this rapidly expanding field. Current and past issues of The Journal of Nuclear Medicine can be found online at http://jnm.snmjournals.org.

JNM is published by the Society of Nuclear Medicine and Molecular Imaging (SNMMI), an international scientific and medical organization dedicated to advancing nuclear medicine and molecular imaging—precision medicine that allows diagnosis and treatment to be tailored to individual patients in order to achieve the best possible outcomes. For more information, visit www.snmmi.org.

Feedzy

Article: bioengineer.org

Continue Reading

Biotech

UCLA Researchers Develop Novel Microscopic Picoshell Particles

Published

on

Production of high-energy fats by microalgae may provide a sustainable, renewable energy source that can help tackle climate change. However, microalgae engineered to produce lipids rapidly usually grow slowly themselves, making it difficult to increase overall yields. 

Production of high-energy fats by microalgae may provide a sustainable, renewable energy source that can help tackle climate change. However, microalgae engineered to produce lipids rapidly usually grow slowly themselves, making it difficult to increase overall yields. 

UCLA bioengineers have created a new type of petri dish in the form of microscopic, permeable particles that can dramatically speed up research and development (R&D) timelines of biological products, such as fatty acids for biofuels. Dubbed PicoShells, the picoliter (trillionth of a liter), porous, hydrogel particles can enable more than one million individual cells to be compartmentalized, cultured in production-relevant environments, and selected based on growth and biomass accumulation traits using standard cell-processing equipment. 

Proceedings of the National Academy of Sciences recently published a study detailing how PicoShells work and their potential applications.

PicoShells consist of a hollow inner cavity where cells are encapsulated and a porous outer shell that allows for continuous solution exchange with the external environment so that nutrients, cell-communication molecules and cytotoxic cellular byproducts can transport freely in and out of the inner cavity. The shell also keeps the small groups of growing cells penned in, allowing researchers to study and compare their behaviors — what they do, how fast they grow, what they produce — to those of other groups inside various PicoShells. 

This new class of lab tool allows researchers to grow living, single-cell microorganisms — including algae, fungi and bacteria — under the same industrial-production conditions, such as in a bioreactor filled with wastewater or an outdoor cultivation pond. 

“PicoShells are like very tiny mesh balloons. The growing cells inside them are effectively fenced in but not sealed off,” said study leader Dino Di Carlo, UCLA’s Armond and Elena Hairapetian Professor in Engineering and Medicine at the UCLA Samueli School of Engineering. “With this new tool, we can now study the individual behaviors of millions of living cells in the relevant environment. This could shorten R&D-to-commercial production timelines for bioproducts from a few years to a few months. PicoShells could also be a valuable tool for fundamental biology studies.” 

PicoShells’ permeability can bring the lab to the industrial environment, allowing testing at a sectioned-off area of a working facility. Growth can occur more quickly and cell strains that perform well can be identified and selected for further screening. 

According to the researchers, another advantage of this new tool is that the analysis of millions of PicoShells is automated since they are also compatible with standard lab equipment used for high-volume cell processing.

Massive groups of cells, up to 10 million in one day, can be sorted and organized by certain characteristics. Continuous analysis could result in ideal sets of cells — ones that are already performing well in the environment with suitable temperature, nutrient composition and other properties that could be used in mass production — in just a few days rather than the several months it would take using current technologies.

The shells can be engineered to burst when the cells inside have divided and grown beyond their peak volume. Those free cells are still viable and can be recaptured for continued research or further selection. The researchers can also create shells with chemical groups that break down when exposed to biocompatible reagent, enabling a multifaceted approach to release selected cells.

“If we want to zero in on algae that are the best at producing biofuels, we can use PicoShells to organize, grow and process millions of single algal cells,” said lead author Mark van Zee, a bioengineering graduate student at UCLA Samueli. “And we can do that in machines that sort them using fluorescent tags that light up to signify fuel levels.”

Currently, cultivating and comparing such microorganisms are done mostly using traditional lab tools, such as microwell plates — cartons that hold several dozen small test tube-like volumes. However, these methods are slow and it is difficult to quantify their effectiveness because it can take weeks or months to grow large colonies for study. Other approaches, such as water-in-oil droplet emulsions, can be used to analyze cells in smaller volumes, but surrounding oils prevent the free exchange of medium into the water drops. Even cells or microorganisms that perform well in lab conditions may not do as well once they are placed in industrial environments, such as bioreactors or outdoor cultivation farms. As a result, cell strains that are developed in the lab often do not exhibit the same beneficial characteristic behavior when transferred to industrial production. 

Microwell plates also are limited in the number of experiments that can be performed, resulting in a great deal of trial and error in finding cell strains that work sufficiently well for mass production.

The researchers demonstrated the new tool by growing colonies of algae and yeast, comparing their growth and viability against other colonies grown in water-in-oil emulsions. For the algae, the team found that PicoShell colonies accumulated biomass rapidly while algae did not grow at all in water-in-oil emulsions. Similar results were found in their yeast experiments. By selecting the top growing algae in PicoShells, the researchers could increase the production of chlorophyll biomass by 8% after only a single cycle. 

The authors said PicoShells could offer a faster alternative to develop new algae and yeast strains, leading to improved biofuels, plastics, carbon-capture materials and even food products and alcoholic beverages. Further refinements to the technology, such as coating the shells with antibodies, could also lead to developing new types of protein-based medicines.

Di Carlo, van Zee and study co-author Joseph de Rutte Ph.D. ’20, a former member of Di Carlo’s research group, are named inventors on a patent application filed by the UCLA Technology Development Group.

The other UCLA authors on the paper are Rose Rumyan, Cayden Williamson, Trevor Burnes, Andrew Sonico Eugenio, Sara Badih, Dong-Hyun Lee and Maani Archang. Randor Radakovits from Synthetic Genomics of San Diego is also an author.

The study was supported by the Presidential Early Career Award for Scientists and Engineers and a planning award from the California NanoSystems Institute (CNSI) at UCLA.

Di Carlo holds faculty appointments in bioengineering, and mechanical and aerospace engineering at UCLA Samueli. He is a member of CNSI and the Jonsson Comprehensive Cancer Center at UCLA.

Read More

Source Here: bioengineer.org

Continue Reading

Trending

DXDD.com