Shaun Mahony's Avatar

Shaun Mahony

@shaunmahony

Studying gene regulation and transcription factor binding with machine learning. Assoc Prof at Penn State. ๐Ÿ‡ฎ๐Ÿ‡ช

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Latest posts by Shaun Mahony @shaunmahony

I guess you could look at it from the perspective of a reviewer. They have already spent hours reading the manuscript and drafting and editing a careful review. And now they should go back and spend more time editing because an LLM sent them automated feedback? How much were they paid again?

25.02.2026 02:35 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

I think itโ€™s high? This was unsolicited feedback on reviews. And hopefully more than a quarter of reviews donโ€™t contain issues that are correctable by an LLM (I.e., inappropriate tone, etc)

24.02.2026 13:18 ๐Ÿ‘ 3 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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๐Ÿงช๐ŸงฌNew preprint We present cryo-EM structures of reconstituted CTCFโ€“nucleosome complexes, showing CTCF dimerization drives nucleosome oligomerization into defined higher-order assemblies. Disrupting CTCFโ€“CTCF interfaces in mESCs reduces looping and impairs differentiation. tinyurl.com/CTCF-nucleos...

09.02.2026 12:54 ๐Ÿ‘ 123 ๐Ÿ” 52 ๐Ÿ’ฌ 4 ๐Ÿ“Œ 3

Maybe theyโ€™re waiting to see if it will melt off by tomorrow? ๐Ÿ˜‚

25.01.2026 14:43 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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In #G3journal, @shaunmahony.bsky.social introduces a mammalian-optimized ChIP-exo (MO-ChIP-exo) protocol that builds upon previous ChIP-exo protocols with systematic optimization of crosslinking, harvesting, and library construction. buff.ly/KfvejKQ

13.01.2026 21:02 ๐Ÿ‘ 2 ๐Ÿ” 1 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Salt?

09.11.2025 03:49 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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Chihuahua or Muffin? Last year, a bizarre picture quiz took the internet by storm as Karen Zackโ€™s images of Animals vs. Food spread virally. Given the recentโ€ฆ

Or for vision ML intro: Chihuahua or muffin

blog.cloudsight.ai/chihuahua-or...

04.11.2025 12:30 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0
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Datasaurus dozen?

en.wikipedia.org/wiki/Datasau...

04.11.2025 12:29 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

The human coder would have been been tasked with validating the code could be held responsible for any mistakes. If we donโ€™t teach coding to students, who will be responsible for validating?

09.10.2025 11:32 ๐Ÿ‘ 10 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

I know they can be very helpful for coding, but I have also seen LLMs make egregious and hard to detect mistakes in code and analysis. When you posed the question about whether it would be any different if you hired a coder to do this - I think the answer is yes, and itโ€™s a matter of responsibility

09.10.2025 11:32 ๐Ÿ‘ 21 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0
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DNA mutagenesis driven by transcription factor competition with mismatch repair Competition between transcription factors and mismatch repair machinery drives localized hypermutation at regulatory elements, with implications for cancer and genome evolution.

I'm very pleased to announce the official publication of our lab's paper "DNA mutagenesis driven by transcription factor competition with mismatch repair" in today's issue of Cell! www.cell.com/cell/abstrac...

02.10.2025 23:37 ๐Ÿ‘ 66 ๐Ÿ” 17 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

Tbh, I CANโ€™T understand why they limit to senior undergrads and 1st yr grad students. Reviewers are assessing a graduate research plan from students that either donโ€™t know what program or what lab they are joining. And then NSF provides funding decisions too late to influence those decisions

27.09.2025 18:42 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0

I thought arXiv accepted preprints?

25.09.2025 21:39 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

A fundamental lesson of modern AI is that scale is essential: training bigger models on bigger datasets unlocks new capabilities. A fundamental lesson of AI engineering is that scaling up isn't trivial: it is not just a matter of spending more money and resources.

22.09.2025 12:15 ๐Ÿ‘ 7 ๐Ÿ” 3 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Heads up: ignore samtools dot org, similarly minimap2 dot com and likely others. It's owned by a known phishing site and while the binaries they offer look valid currently (but note they may be serving us different binaries to others), that could change.

Ie: it's not us (Samtools team)! Be warned

15.09.2025 08:40 ๐Ÿ‘ 146 ๐Ÿ” 127 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 5
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Trustees increase Penn State presidentโ€™s total pay by $1M. See the terms The package also included a contract extension for Bendapudi.

Penn State's closing seven Commonwealth campuses and laying off up to 500 employees, but it can afford an extra $1M/year for the President's pay? www.centredaily.com/news/local/e...

12.09.2025 19:51 ๐Ÿ‘ 1 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

Within 24hrs, our board of trustees closed the local NPR station because transferring to new owners would have cost too much ($17M over 5 yrs) AND they increased the President's pay (total >$20M over next 7 yrs). How does this further PSU's land grant mission to extend knowledge to the public?

12.09.2025 19:51 ๐Ÿ‘ 3 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Well yeah, but you said yourself above - an NoA is permission to get reimbursed for allowable expenses. If the NoA approves all funds and the end date is 4 years in the future, I donโ€™t see where they can limit annual without a new NoA

09.09.2025 21:26 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

I think it would be hard for them to implement any enforcement of annual spending levels when the NoA has all funds, right? Wouldnโ€™t it require a new NoA that pulls back funds? I think the deviation would need to be extreme before they would do that

09.09.2025 21:09 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

Iโ€™ve heard from those who have received NoAs with the full budget and the expiry set to the project end date. No limits in the NoAs as far as they reported and explicit guidance from POs that annual budgets are flexible

09.09.2025 21:01 ๐Ÿ‘ 2 ๐Ÿ” 2 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0

I know of some MYF awards that have already been made. Claus is correct- all money is available up front to spend on any timeline

09.09.2025 20:36 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 2 ๐Ÿ“Œ 0
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We also see varied associations between ApiAP2 transcription factor binding sites and chromatin states, suggesting a new way to categorize the activities of these TFs.

07.09.2025 15:10 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0
Plot showing the dynamic transitions between chromatin states across the Plasmodium IDC

Plot showing the dynamic transitions between chromatin states across the Plasmodium IDC

Chromatin states are highly dynamic during Plasmodium blood stage development; almost two thirds of the genome changes chromatin state during the IDC.

07.09.2025 15:10 ๐Ÿ‘ 2 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
Chromatin states defined during the P. falciparum IDC

Chromatin states defined during the P. falciparum IDC

We found 11 chromatin states during the P. falciparum IDC, defined by combinations of chromatin accessibility and histone modifications. Some of these states comprise unusual combinations of histone marks and associations with regulatory activities that are not seen in higher eukaryotes.

07.09.2025 15:10 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
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New preprint from Alan Brown in our lab, who is co-advised by @llinaslab.bsky.social. In this study, Alan studied chromatin state dynamics during the asexual intraerythrocytic development cycle (IDC) of the human malaria parasite, Plasmodium falciparum.

www.biorxiv.org/content/10.1...

07.09.2025 15:10 ๐Ÿ‘ 3 ๐Ÿ” 1 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
Figure showing that K562 CTCF ChIP-exo data provides consistent results between 1 and 5 sonication cycles, while data quality fades out from that point onwards.

Figure showing that K562 CTCF ChIP-exo data provides consistent results between 1 and 5 sonication cycles, while data quality fades out from that point onwards.

One example: we found a range of sonication settings that provide similar results (at least for CTCF in K562). I kinda expected to see different cohorts of sites in differentially accessible chromatin being "released" by different sonication settings, but we see no evidence for that.

23.08.2025 19:16 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 0 ๐Ÿ“Œ 0

The manuscript contains practical advice on protocol aspects such as crosslinking conditions and develops a newly library construction workflow to take advantage of newer kits and techniques.

23.08.2025 19:16 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
Side-by-side comparison of K562 CTCF ChIP-exo data from three protocols: MO-ChIP-exo, ChIP-exo v5.0 and ChIP-exo v1.1. MO-ChIP-exo is shown to have higher FRiP scores and higher peak counts.

Side-by-side comparison of K562 CTCF ChIP-exo data from three protocols: MO-ChIP-exo, ChIP-exo v5.0 and ChIP-exo v1.1. MO-ChIP-exo is shown to have higher FRiP scores and higher peak counts.

MO-ChIP-exo offers improved signal-to-noise compared with other versions of the protocol (as measured by Fraction of Reads in Peaks - FRiP scores).

23.08.2025 19:16 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0
Overview of the existing ChIP-exo protocol alongside the new MO-ChIP-exo protocol. The figure highlights protocol steps that we investigated in our manuscript.

Overview of the existing ChIP-exo protocol alongside the new MO-ChIP-exo protocol. The figure highlights protocol steps that we investigated in our manuscript.

Daniela systematically investigated most steps in the protocol. Boxes with green highlights here are steps that were investigated and modified in our new mammalian-optimized ChIP-exo protocol (MO-ChIP-exo).

23.08.2025 19:16 ๐Ÿ‘ 0 ๐Ÿ” 0 ๐Ÿ’ฌ 1 ๐Ÿ“Œ 0