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Posts by Amir Mitchell

Funding agencies should impose application funnels that maintain ~25% success rates (very low rates, with the same pool of money, are only seemingly kind to the applicants and are detrimental to collective productivity)

4 days ago 4 0 0 0

IMO, the real cost of low success rates is not the time wasted on reviews but the time researchers collectively waste developing grant proposals that will not be funded. 1/2

4 days ago 18 2 1 0

It's an important piece (provocative, yes, even triggering). It surfaces one the biggest challenges research universities will soon face. The current incentive model in (US) academia awards progress more than anything which only compounds the problem

1 month ago 2 0 0 0

Absolutely, what can be more fitting 😉

1 month ago 0 0 0 0

Our latest paper was just published. Will prepare a full thread very soon 🦠🧪🤖

1 month ago 8 5 1 0

🎯

2 months ago 0 0 0 0
A screenshot of our first conversation with an AI bot over slack

A screenshot of our first conversation with an AI bot over slack

I'm developing an #AI bot name HAL to assist with our research. Here's our first conversation with it over Slack (didn't tell the lab before deploying it) 😂

2 months ago 3 1 2 0

I tip my hat at the authors putting in all the efforts for these follow-up experiments

2 months ago 0 0 0 0

Just concluded a 2-week coding spree with a student using VS+codex. The x5-10 gain in productivity blew my mind 🤯. BUT, I'm also sure that for inexperienced coders AI-coding makes garbage-in-gargbe-out pitfall inescapable.

2 months ago 5 0 0 0
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Beautiful “full arc” story on abx response with impressive level of mechanistic detail (could be a class example for undergrad microbiology lesson)

3 months ago 1 0 0 0

Congrats on publishing this beautiful work! I'm still mind-blown that: (1) there's a 7th RND pump in E. coli and (2) that its somewhat unclear what it actually pumps out IRL

3 months ago 2 0 1 0

It's a beautiful approach! But it's very disappointing that there is actually NO phenotypic characterization of the rearranged strains in the manuscript ... hoping it's an evolving manuscript that they'll keep updating

3 months ago 0 0 0 0

Totally agree. Fail early, fail often (and aim high) is something more scientists need to live by.

3 months ago 1 0 0 0

Huge credit to @carmenli.bsky.social for her persistence in chasing a moonlight project into its beautiful completion. Credit also goes Ethan Chang, the rotation student contributing to this work 9/9

3 months ago 1 0 0 0

Btw, note that “inactivation” can mean more than enzymatic degradation and includes any process that reduces effective drug activity over time (chemical modification, sequestration, etc) 8/9

3 months ago 2 0 1 0
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We then tested if this assosiation holds through our entire dataset. We used a functional assay for drug inactivation on all drugs and found the association holds up. A long-lag inhibition phenotype is a strong indicator of drug inactivation 7/9

3 months ago 2 1 1 0
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That pushed us to ask whether cellular defenses might impact curve profiles. We cloned different resistance cassettes and measured how they altered the potency-matched growth curves. This strongly hinted that active drug inactivation underlies a long-lag inhibition profile 6/9

3 months ago 1 1 1 0
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Overlaying the known mechanisms of action over the barycentric landscape ruled out this effect stem exclusively from how drug target bacteria (since drugs with the same mechanism can land in very different regions of the landscape) 5/9

3 months ago 1 0 1 0
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Clustering drug by their impact on lag/rate/yield clearly revealed that they vary hugely in how they inhibited growth. In extreme cases, a drug solely affected only a single parameter 4/9

3 months ago 1 0 1 0
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To compare drugs fairly, we didn’t use an arbitrary concentration. Instead, we interpolated each drug to a potency-matched condition (the concentration expected to produce the same overall level of inhibition) 3/9

3 months ago 1 0 1 0
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So we assembled a new carefully curated dataset with growth curves across almost forty drugs, measured across multiple sub-inhibitory concentrations. For each curve, we quantified intuitive its key features: lag, growth rate, and yield 2/9

3 months ago 2 1 1 0
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Predicting drug inactivation by changes in bacterial growth dynamics - npj Antimicrobials and Resistance npj Antimicrobials and Resistance - Predicting drug inactivation by changes in bacterial growth dynamics

Our recent paper in npj Antimicrobials and Resistance is a great example of scientific serendipity: after staring at thousands of bacterial growth curves over many studies, we started wondering whether the curve shapes themselves carry mechanistic information 1/9 🦠🧪
www.nature.com/articles/s44...

3 months ago 47 26 2 2

This was a true collaboration between physicists (Andrew Mugler and @motasemelgamel.bsky.social), an immunologist (Michael Brehm from @umasschan.bsky.social ), and systems biologists (with @serkansayin.bsky.social and Brittany Rosener from my lab also at @umasschan.bsky.social ) (7/7)

4 months ago 3 0 0 0
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Beyond providing (to our knowledge) the first dynamical model for tumor colonization, our study matters given the fierce debate on the tumor microbiome. These statistical “fingerprints” may help distinguish genuine colonizers from technical artifacts/contamination (possibly even by microscopy) (6/7)

4 months ago 2 1 1 0
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The surprise: lineage sizes formed a scale-free power law that matches Zipf’s law (rank–frequency slope ~−1). This signature was robust across dozens of tumors and multiple collection days post bacteria intratumor injection (5/7)

4 months ago 3 0 1 0
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When we injected bacteria directly into the tumor (circumventing the bottleneck), we detected thousands of colonizing lineages, yet their sizes were still highly uneven (ruling out early tumor arrivers dominate) (4/7)

4 months ago 2 0 1 0
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Since we used genetically barcoded bacteria, we could also monitor growth of individual colonizers. We found that growth was extremely uneven with a handful of lineages becoming dominant (“winner-takes-most”) (3/7)

4 months ago 2 1 1 0
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Main takeaways: Post systemic infection, there's a tight colonization bottleneck (per-cell colonization probability ~0.005%). Yet, once colonization happens, growth is remarkably fast (~50 min generation time) and bacterial load in tumors approaches saturation within a day (2/7)

4 months ago 2 0 1 0
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We just published in @molsystbiol.org with the Mugler lab (UPitt) on bacterial population dynamics during tumor colonization (mouse model). Our study was guided by a Luria–Delbrück-style idea: infer mechanism from statistics (1/7) 🧪🦠
doi.org/10.1038/s443...

4 months ago 18 12 2 0
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The pivot penalty in research - Nature An analysis of millions of scientific papers and patents reveals a ‘pivot penalty’ when researchers shift direction, with the impact of studies decreasing rapidly the further they move from their prev...

The (very real) cost of changing your research field. Absolutely true! But the freedom to pivot is one of the greatest things in this profession.
www.nature.com/articles/s41...

10 months ago 4 1 0 0