Nagissa Mahmoudi
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nagissa.bsky.social
Nagissa Mahmoudi
@nagissa.bsky.social
Associate Professor at McGill University 🇨🇦
Interested in what microbes eat in the ocean and why. #microbes #carbon #biogeochemistry.
www.geomicromcgill.com
Pinned
🚨New preprint from our lab!🚨

We trace the evolution of microbial exoenzymes and uncover their role in Earth’s oxygenation. By recycling nutrients, exoenzymes helped fuel cyanobacteria and set off feedbacks that sustained the long-term rise of O₂.

#MicroSky 🧪 🦠 🌎

www.biorxiv.org/content/10.1...
Microbial exoenzymes catalyzed the transition to an oxygenated Earth
Microbial exoenzymes, extracellular enzymes secreted to degrade complex organic polymers, are essential for recycling carbon and nutrients, thus sustaining primary productivity in todays oceans. Yet, ...
www.biorxiv.org
Reposted by Nagissa Mahmoudi
Congratulations to the 2025 recipient of the Volvo Prize, @naomioreskes.bsky.social! Naomi's work addresses vital issues such as why we need to trust science; a topic that becomes even more important with every new day.

Read more here: www.environment-prize.com/laureates/na...
Why we should trust scientists
Many of the world's biggest problems require asking questions of scientists -- but why should we believe what they say? Historian of science Naomi Oreskes thinks deeply about our relationship to belie...
www.ted.com
November 2, 2025 at 8:40 PM
Reposted by Nagissa Mahmoudi
both are right: the best is marine microbiology
November 2, 2025 at 5:47 PM
Reposted by Nagissa Mahmoudi
🌊 A pandemic-era breakthrough has allowed scientists to literally expand our view of plankton. By using ultrastructure expansion microscopy, researchers visualised the inner workings of hundreds of marine species for the first time

www.sciencedaily.com/releases/202...
A new microscopy breakthrough is revealing the oceans’ invisible life
A pandemic-era breakthrough has allowed scientists to literally expand our view of plankton. By using ultrastructure expansion microscopy, researchers visualized the inner workings of hundreds of mari...
www.sciencedaily.com
November 2, 2025 at 5:53 PM
Reposted by Nagissa Mahmoudi
I want to see the particles that sink carbon to the deep ocean, all the time and in real time.This summer we built an instrument that collects images of sinking particles every second, and visualizes them in 5 different ways. @mbarinews.bsky.social
youtu.be/4xXGlnCoik8
How MBARI scientists are studying the ocean’s carbon flux in real time
YouTube video by MBARI (Monterey Bay Aquarium Research Institute)
youtu.be
November 2, 2025 at 6:41 PM
Reposted by Nagissa Mahmoudi
What should we do if a signal from an extraterrestrial intelligence is detected? A paper from Michael Garrett and others outlines an updated SETI protocol.

#SETI 🧪
SETI Post-Detection Protocols: Progress Towards a New Version
The International Academy of Astronautics (IAA) SETI Committee has long provided guiding principles for responding to a potential detection of a SETI signal. The foundational Declaration of Principles...
arxiv.org
November 2, 2025 at 12:40 PM
There has never been a more confusing time to shop for women’s jeans. Every pair is fighting for a different decade.
October 15, 2025 at 6:34 PM
Reposted by Nagissa Mahmoudi
NASA unit JPL to lay off about 550 workers, citing restructure
NASA unit JPL to lay off about 550 workers, citing restructure
The Jet Propulsion Laboratory is a research and development lab funded by NASA — the federal space agency — and managed by the Caltech.
cnb.cx
October 13, 2025 at 7:23 PM
Reposted by Nagissa Mahmoudi
'When authoritarians seize power, it is crucial to recognize courageous defenders of freedom who rise and resist,' the Norwegian Nobel Committee said as it announced Maria Corina Machado as the winner of the 2025 Nobel Peace Prize
October 10, 2025 at 9:31 AM
Reposted by Nagissa Mahmoudi
Many sea stars begin life as young fairy-like creature (called a brachiolaria) that float through the open ocean. Eventually, a small star forms within them (here in yellow). The fairy-like brachiolaria sinks under the star’s weight, and the star pops out!
🎥@the_story_of_a_biologist (on Insta)
October 9, 2025 at 4:24 AM
Reposted by Nagissa Mahmoudi
A cartographer, a composer, a neurobiologist, and a novelist are among the recipients of this year's "Genius Grants." Each Fellow will receive a no-strings attached award of $800,000. n.pr/4h19OGf
Thinkers, dreamers, doers: Here's who made the 2025 MacArthur Fellow list
A cartographer, a composer, a neurobiologist, and a novelist are among the recipients of this year's "Genius Grants." Each Fellow will receive a no-strings attached award of $800,000.
n.pr
October 9, 2025 at 6:15 AM
Reposted by Nagissa Mahmoudi
Omar Yaghi, the new Nobel Laureate, was born to a Palestinian refugee family.
npr.org NPR @npr.org · Oct 8
Susumu Kitagawa, Richard Robson and Omar M. Yaghi will share the prize. Their structures can "capture carbon dioxide, store toxic gases or catalyse chemical reactions," the committee said. n.pr/4nOvwQs
Research on metal-organic frameworks gets the chemistry Nobel Prize
Susumu Kitagawa, Richard Robson and Omar M. Yaghi will share the prize. Their structures can "capture carbon dioxide, store toxic gases or catalyse chemical reactions," the committee said.
n.pr
October 8, 2025 at 3:57 PM
Reposted by Nagissa Mahmoudi
This year’s #NobelPrize in Chemistry has gone to the architects of molecular “cages” that could be used for everything from carbon capture to drug delivery. https://scim.ag/4mTE1Z6
October 8, 2025 at 2:00 PM
Interested in life’s co-evolution with planetary environments?
🌎🦠🧪

I'm looking for a postdoc to join my group at #McGill and happy to sponsor applicants for the TSI fellowship.

Please reach out if interested!

academicjobsonline.org/ajo/jobs/30777
McGill University, Trottier Space Institute
Job #AJO30777, Trottier Space Institute Postdoctoral Fellow, Trottier Space Institute, McGill University, Montreal, Quebec, CA
academicjobsonline.org
October 7, 2025 at 12:19 PM
Reposted by Nagissa Mahmoudi
The @uncchapelhill.bsky.social Department of Biology is searching for tenure-track Assistant Professor in Plant Molecular Biology. Chapel Hill is a wonderful place and Biology is an amazing group of people. To apply, see:
unc.peopleadmin.com/postings/307...
October 6, 2025 at 7:30 PM
Reposted by Nagissa Mahmoudi
New paper! PhD student Mia Tuccillo has uncovered another big impact of past warming in Greenland: lakes lost oxygen for thousands of years and cyanobacteria took over 🦠 🧪 🦠. It's kinda yikes...
With collaborator @geobiomaggie.bsky.social (1/3)
October 1, 2025 at 3:09 AM
Reposted by Nagissa Mahmoudi
The vast majority of permafrost exists in the subsurface. What happens when this deep, ancient permafrost thaws? How fast does it take microbial communities to "wake up"?

This project now published in JGR, with @isotopes.bsky.social , @kopflab.bsky.social , et al., aims to address that question!
Microbial Resuscitation and Growth Rates in Deep Permafrost: Lipid Stable Isotope Probing Results From the Permafrost Research Tunnel in Fox, Alaska
Microbial growth is extremely slow within the first 30 days of thaw. Temperature may drive which taxa are active, but not growth rates Subsurface microbes preferentially produce glycolipids over ...
agupubs.onlinelibrary.wiley.com
September 26, 2025 at 6:35 PM
Deep ocean microbes are starving but does feeding them fresh carbon make them eat the old stuff?

Our new study shows it doesn’t. The persistence of this carbon appears to come from its chemical stability, not from microbial starvation.

🌊🦠 🧪 #MicroSky #MarineSky

journals.asm.org/doi/epub/10....
Testing the priming effect in the deep ocean: are microorganisms too starved to consume recalcitrant organic carbon?
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journals.asm.org
September 26, 2025 at 12:17 PM
Reposted by Nagissa Mahmoudi
Rice’s Masiello Honored as Fellow of the American Geophysical Union

Carrie Masiello, the esteemed W. Maurice Ewing Professor of Biogeochemistry at Rice University, has been honored with election as a fellow of the American Geophysical Union (AGU), a prestigious recognition reserved for those who…
Rice’s Masiello Honored as Fellow of the American Geophysical Union
Carrie Masiello, the esteemed W. Maurice Ewing Professor of Biogeochemistry at Rice University, has been honored with election as a fellow of the American Geophysical Union (AGU), a prestigious recognition reserved for those who have made extraordinary contributions to Earth and space sciences. This accolade places Masiello among an elite group of scientists whose work has profoundly advanced our understanding of Earth systems, with only a fraction of AGU members ever attaining this distinction since the fellowship program began in 1962.
scienmag.com
September 24, 2025 at 6:18 PM
Reposted by Nagissa Mahmoudi
🚨 ‘Earth system engineers’ and the cumulative impact of organisms in deep time
sciencedirect.com/science/arti...

Honored to be among the long author list of this new paper out now in @cp-trendsecolevo.bsky.social that looks to bridge the ecosystem engineering and paleontological literature.
September 23, 2025 at 7:57 PM
Reposted by Nagissa Mahmoudi
So you're a scientist about to face a government shutdown?

Have you considered becoming a rock star?

It's easy AND profitable! 🎸🧪

Let's list off five scientists who turned rockers:
September 23, 2025 at 11:38 PM
Reposted by Nagissa Mahmoudi
🐻🐻🐻🐻
It is finally here.
Fat Bear Week 2025.
🐻🐻🐻🐻

Vote for the fattest, portliest, chubbiest bear of Katmai NP (@fatbearweek.bsky.social). Some of these chonks weigh more than half a ton, and have gained over 100kg since July.

Who will win this year?

Voting is open: explore.org/fat-bear-week
🧪🌍🦊
September 23, 2025 at 11:14 AM
Reposted by Nagissa Mahmoudi
🚨 Job Alert! 🚨

We're hiring a Research Project Manager to join our #THRiVElab team at U. Manitoba.

📍 Winnipeg or Remote (in Canada)
💰 Up to $85k
🔗 Apply: www.umanitoba.ca/careers (#38881)
🌐 About us: www.thrivediscovery.ca/staff-positi...

Know someone perfect for this? Please boost or share! 🙏
June 20, 2025 at 10:29 PM
Reposted by Nagissa Mahmoudi
🌱 Using ‘compelling’ methods, including #CryoET, researchers mapped spinach thylakoid membranes at single-molecule precision, revealing how photosynthetic complexes are organised and settling long-standing debates on chloroplast architecture.
buff.ly/j3TSIkn
September 20, 2025 at 1:59 PM