Joshua Weitz

@joshuasweitz

Professor of Biology & Institute for Health Computing, U of Maryland; explores how viruses impact human & environmental health; 'Asymptomatic' (JHU Press & 'Science Matters' (

3774 Siguiendo11.463 Seguidores3005 Publicaciones

Bluesky

¿Es tu perfil?Reclámalo y joshuasweitz.dirty.social es tuyo.Reclamar perfil

Joshua Weitz@joshuasweitz· 3d

Oh and measles... there are already more documented cases in 2026 in the US than in all of last year (and last year had the highest number in 25+ years). www.cdc.gov/measles/data...

Yearly measles cases... 2026 is now another record-breaking year.

https://www.cdc.gov/measles/data-research/index.html

Joshua Weitz@joshuasweitz· 11d

60,000+ comments on OMB’s proposal to politicize grants. The lesson: speak up. It makes a difference & it’s not over yet. 🎁 wapo.st/44YL4t1

WP story by Riley Beggin

Senate aims to block White House from gaining new power over science funding

https://wapo.st/44YL4t1

Joshua Weitz@joshuasweitz· 22d

LinkedIn is evolving and maturing. It's not just congratulations anymore! Who knew that saying universities do science would be so triggering - live and learn!

Phillip Brink Murray from "Art & Science & Industry" has so many things to say like "pipe down, idiot" and "you're the one playing politics, stupid", and "go talk to your therapist about, sissy". I don't know who he is, but doesn't seem like he would be fun to talk to at parties.

Joshua Weitz@joshuasweitz· 29d

New Science & Community Impacts Mapping Project (#SCIMaP) analysis on the impact of the WH plan to eliminate NSF's Social, Behavioral, and Economic Sciences directorate. @malar0ne.bsky.social @asinclair.bsky.social @cl10.bsky.social @alexmusicwrites.bsky.social scienceimpacts.org/insights/SBE...

Insight blog

"Cuts to NSF’s Social, Behavioral and Economic Sciences (SBE) Directorate will have significant economic impacts nationwide"
https://scienceimpacts.org/insights/SBE-2026-07-13

Joshua Weitz@joshuasweitz· Jul 13

Dashboard with analysis of comments & github source link omb-financial-assistance-comments.netlify.app

Regulation for Federal Financial Assistance
Proposed OMB rule revising the Uniform Guidance for federal financial assistance (2 CFR, including §200.205 and §200.340) that commenters describe as shifting grant review and funding decisions from independent expert peer review toward political appointees, adding ideological conditions on awards, and restricting allowable costs.
OMB Docket: OMB-2026-0034

with cross-tabs, including 94% oppose the rule.

Joshua Weitz@joshuasweitz· Jul 8

Viruses of Microbes 2026 in Prague #VoM2026 Immersive conference spanning cells, populations, and ecosystems including basic and translational discoveries... ... and now mobilizing well beyond the conference hall. h/t @pavol.bsky.social

Joshua Weitz@joshuasweitz· Jul 2

As a @washingtonpost.com subscriber and admirer of many of their news team, it is shocking (but not surprising) to read this nihilistic and Orwellian OpEd from Scott Atlas: adviser to Trump I, member of the Hoover Institution at Stanford who wants to literally: "Abolish the NIH" wapo.st/4eWDsMf 🧵

OpEd "Abolish the NIH" - Scott Atlas, Hoover Institution, July 2, 2026

https://wapo.st/4eWDsMf

Joshua Weitz@joshuasweitz· Jul 1

Which means, in practice, milder diseases (when considering the term 'mild' at individual scales) can lead to far worse population scale outcomes. academic.oup.com/pnasnexus/ar...

SARS, 2003-2004
~2.4 secondary infections
~10% fatality rate
~800 fatalities

vs.

COVID-19, 2020-2023
~3 secondary infections
~0.5-1% fatality rate
>20M+ estimated fatalities

Joshua Weitz@joshuasweitz· Jul 1

Congratulations to @malar0ne.bsky.social who was awarded a Best Talk prize for her #SCIMaP presentation on 'Widespread Economic Impacts of Federal Research Cuts in Local Communities' at the International Conference on the Science of Science and Innovation: icssi.org

International Conference on the
Science of Science and Innovation
June 29 - July 1, 2026 in Boulder, Colorado

Joshua Weitz@joshuasweitz· Jun 24

Now imagine scaling up a single costly, wasteful, and flawed project to tens of billions of dollars in award decisions at NIH, NSF + more that are currently made by domain experts and at risk - via proposed OMB rules - of being made by political officials to fulfill administration priorities.

Picture: National Park Service workers clean the reflecting pool.
Violet Jira/NOTUS

Source:
https://www.notus.org/metro/trump-american-flag-blue-reflecting-pool-is-green-with-algae

Joshua Weitz@joshuasweitz· Jun 23

Dan is an excellent, rigorous, and committed voice with a range that spans people, systems, and science. His last three stories given you some sense of what SciAm and LabX just lost and what we will lose collectively without institutions & the people who can tell stories about why science matters.

Stories by Dan Vergano
Dan Vergano is senior editor, Washington, D.C., at Scientific American. He has previously written for Grid News, BuzzFeed News, National Geographic and USA Today. He is chair of the New Horizons committee for the Council for the Advancement of Science Writing and a journalism award judge for both the American Association for the Advancement of Science and the U.S. National Academies of Sciences, Engineering, and Medicine.

The entrance of 2514 Eisenhower Avenue, where the National Science Foundation is also located, is seen on July 8, 2025, in Alexandria, Va.
Politics
June 18, 2026
Trump administration reverses course on plan to dismantle ocean monitoring network

The effort to pull some 900 ocean-monitoring buoys and sensors from the water drew backlash from scientists and lawmakers

Dan Vergano

A man standing at a podium in front of a blue background.
Medicine
June 16, 2026
Proposed White House regulations could kill 5,000 clinical trials, analysis finds

The Trump administration is mulling new rules that would give political appointees final say on research grants

Dan Vergano

Collage illustration showing the perils of funding in science and including portraits of two individuals mentioned in the article. Illustration by Max-o-matic and photographs by Emily Butler Photography and Getty Images.
Policy
June 16, 2026
How to fix science

The federal funding system for scientific research in the U.S. is crumbling. Here’s how it can be rebuilt

Dan Vergano

Joshua Weitz@joshuasweitz· Jun 11

If Congress is serious about advancing science, it must look beyond top-line budgets and engage now when rules for how research budgets are prioritized, allocated, and spent are at risk of becoming entirely politicized. @standupforscience.net fight2win.standupforscience.net?_gl=1*1wb02h....

OMB Rule Related Resources
View the full OMB-2026-0034 Proposed Rule
View the SUFS Overview of the Rule Proposal
Read Dr. Elizabeth Ginexi's Overview on the Rule Proposal
View the SUFS Guide to Leaving Public Comments
Learn How To Talk to Anyone About the New OMB Rule
More ways to Stand Up for Science!
Add Your Voice to Stop OMB's Attack on American Science
Comment on the proposed rule to demand a stop Vought's destruction of independent science & research

Joshua Weitz@joshuasweitz· Jun 6

At minimum the paper needs full details of the mathematical model w/access to Supplementary Information so that the community can assess and weigh in; the links to the supplementary figures appear broken and first supp is clearly mislinked... CDC modeling capacity should not be 10+ years back.

Apparent list of supporting files for Ebola modeling paper includes 'age-adjusted colorectal cancer death rates' and other links do not work.

Joshua Weitz@joshuasweitz· Jun 6

And yes branching process can generate noise (which seems appealing from a 'realism' perspective), but if you run them without (local) susceptible depletion then they stop representing things to close to reality quite quickly. There are other options. www.sciencedirect.com/science/arti...

Fig. 1. Stochastic realizations of a SEIRD epidemic include substantial variability in epidemic growth rate. (Left) Each panel denotes a randomly chosen trajectory for which the cumulative case count exceeded 50 (gray period) followed by a 42 day measurement period (black period). The estimated
in the measurement period is denoted in the upper left of each panel. (Top Right) Variation in cumulative case counts once a threshold is reached. The results are for 5817 epidemics where the measurement time denotes the period after the first day the trigger was crossed. The solid blue line denotes the median number of cases and the shaded region the central 95% of simulations. (Bottom Right) Variation in the characteristic time estimated from simulation data,
. In all cases, simulations correspond to stochastic simulations of a SEIRD model in which
,
,
, TE=11, TI=6, TD=4, f=0.7 and
. The theoretically expected characteristic time is
. The median characteristic time is
. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.).

Joshua Weitz@joshuasweitz· Jun 5

Many ways to raise your voice & the time is now, made easier & systematic by @standupforscience.net: fight2win.standupforscience.net?_gl=1*13p5tf....

Headline action page from https://www.standupforscience.net/

On May 29, the Office of Management and Budget posted a sweeping regulatory change that will end American science as we know it.
Take Action NOW!
It’s time to fight back! Head to the SUFS Action Center to:
Learn how to write public comments

Submit YOUR public comment

Contact your Members of Congress

Learn how to talk about this new proposed rule and why it matters

Joshua Weitz@joshuasweitz· Jun 1

Delighted to share news that @weitz-group.bsky.social postdoc @juliepourtois.bsky.social has been selected along with Spencer Hobson-Gutierrez & James Richardson as inaugural Quantitative Biology Initiative Postdoctoral Fellows at the University of Maryland, Biology: biology.umd.edu/news/umds-qu...

UMD's Quantitative Biology Initiative Announces Inaugural Postdoctoral Fellow Cohort

https://biology.umd.edu/news/umds-quantitative-biology-initiative-announces-inaugural-postdoctoral-fellow-cohort

Joshua Weitz@joshuasweitz· May 29

Correct. fight2win.standupforscience.net @standupforscience.net @cdelawalla.bsky.social

Stop Vought. Save Science.

https://fight2win.standupforscience.net/

Joshua Weitz@joshuasweitz· May 29

Many thanks to the entire team, including P. Fremont, @beckettstephen.bsky.social, D. Muratore, @d2mory.bsky.social, E. Carr, O. Jahn, C. Follett, @dtalmy.bsky.social, D. Lindell, S. Dutkiewicz, and the Simons Foundation for critical funding and support. www.biorxiv.org/content/10.6... /🧵

Title and authors of
https://www.biorxiv.org/content/10.64898/2026.05.27.728272v1

Viral impacts on plankton standing stocks, primary productivity, and biogeochemistry in a model ocean
View ORCID ProfilePaul Frémont, View ORCID ProfileStephen J. Beckett, View ORCID ProfileDaniel Muratore, View ORCID ProfileDavid Demory, View ORCID ProfileEric Carr, View ORCID ProfileOliver Jahn, View ORCID ProfileChristopher L. Follett, View ORCID ProfileDavid Talmy, View ORCID ProfileDebbie Lindell, View ORCID ProfileJoshua S. Weitz, View ORCID ProfileStephanie Dutkiewicz

Joshua Weitz@joshuasweitz· May 29

But in building vDarwin, we wanted to move beyond a single modality of cell fate outcomes and explore the feedback of lysates on the community dynamics.We did so by including a parameter that can shift the balance of lysates towards shunt vs. shuttle processes.

Lysis can direct to dissolved or particular organic matter. Three illustration of the range considered here, from 0% to DOM (viral shuttle) to 100% to DOM (viral shunt).

Joshua Weitz@joshuasweitz· May 29

Indeed, one of the first pieces of evidence that we were on the right track was the vDarwin could recapitulate densities that are consistent with open ocean observations and existing Darwin output (without viruses), further suggesting that virus-free models have embedded virus effects implicitly.

Comparison of simulations without viruses vs. that with viruses assuming all lysates are directed to DOM (i.e, viral shunt = 100%)

Joshua Weitz@joshuasweitz· May 29

This is what vDarwin now offers: enabling simulations to directly explore the impacts of explicit inclusion of virus infection, lysis, and loss as part of a 3D global circulation model, part of the larger "Darwin" project. darwinproject.mit.edu

https://darwinproject.mit.edu/

Title over a simulation of the oceans.

Joshua Weitz@joshuasweitz· May 29

then assembling and analyzing viral and microbial abundances in global ocean datasets to help ground efforts to compare results from theory to in situ measurements; www.nature.com/articles/nmi...

Figure 2 | Variation in virus and microbial abundances and the VMR. a, Microbial abundance versus virus abundance coloured by depth. Each point represents a biological sample. Contours denote regions of equal probability distribution in the data set. b, Histogram of the logarithm of VMR. Top and bottom panels correspond to near- and sub-surface water column samples, respectively. The red arrow denotes the median value and the blue arrows denote the central 95% range of values. The numbers associated with each arrow denote the non-transformed value of VMR.

Joshua Weitz@joshuasweitz· May 29

In fact, the challenge was immense. This working group managed to take major steps in the direction of integration, first characterizing the elemental composition of virus particles and its impact on shifting concentrations of nutrients as a result of lysis; www.nature.com/articles/nrm...

Figure 4 | Virus-induced transformation of elemental content in cellular debris following lysis. a | After lysis, the contents of a host are released as virus particles and other cellular debris (that is, the lysate). The relative carbon, nitrogen and phosphorus levels in the virus particles and the lysate are shown in bars; the bar height is normalized
in each case by the total amount of the element in the host. Bar heights are based on the hypothetical infection of Prochlorococcus sp. MED4 host under phosphorus‑replete conditions by a podovirus with 70 nm diameter head. Note that, in fact, the total carbon, nitrogen and phosphorus content differs between the host and the virus.

Joshua Weitz@joshuasweitz· May 29

The project has a long origin story, dating back at least 15 years, when @labwilhelm.bsky.social and I co-organized a NIMBioS working group on 'Ocean Viral Dynamics'. legacy.nimbios.org//workinggrou... (bonus points for recognizing who's who!)

NIMBioS Ocean Viral Dynamics working group circa 2012.

We were younger then!

https://legacy.nimbios.org//workinggroups/WG_ocean_viral_dyn

Joshua Weitz@joshuasweitz· May 29

Viruses are highly abundant in the oceans, but there is one place you won't typically find them: in global ocean ecosystem models... until now. Introducing "vDarwin", an explicit integration of viruses into the MITgcm/Darwin global ecosystem framework: www.biorxiv.org/content/10.6... a 🧵

Integration of a model of viral lysis, shunt and shuttle in a large scale ocean circulation model. (A) Schematic of the large scale ocean circulation model (MITgcm): major surface ocean circulation patterns and the schematic of the advection/diffusion are represented. Note that vertical grid spacing increases with depth (i.e., layers become thicker). (B) Simplified ecosystem represented in the study. For simplicity nitrogen remineralization to nitrite and nitrate and mortality fluxes to DOM and POM are not represented. (C) Schematic of the vDarwin ecosystem model integrated in the large scale circulation model. It represents a simplification of the ecosystem presented in (B) assuming that N is the limiting nutrient. It includes the growth of a single phytoplankton type, viral lysis, zooplankton grazing, the viral shunt and shuttle and remineralization (note that remineralizing bacteria are not explicitly represented).

Joshua Weitz@joshuasweitz· May 21

Jan 16, 2026: The New Vision from NIAID Taubenberger, Powers and Bhattacharya May 21, 2026: Taubenberger is out, more in @statnews.com via @helenbranswell.bsky.social & @aniloza.bsky.social www.statnews.com/2026/05/21/n...

The new vision from the National Institute of Allergy and Infectious Diseases (NIAID) - in Nature Medicine
Jeffery K Taubenberger, John H Powers III, Jay Bhattacharya

https://pmc.ncbi.nlm.nih.gov/articles/PMC12820581/

Joshua Weitz@joshuasweitz· May 19

We need more conversations, not less. More public engagement, rather than hiding and hoping that the threat will dissipate. More frank discussions of the ongoing harm and the missed opportunities to transform our world for the better. And we cannot wait until 2029.

The message of the talk: "It is possible to confront and contest attacks on science and build a better future in ways that are grounded in evidence, persuasive & bridge the ideological divide... & we cannot wait until 2029."

Joshua Weitz@joshuasweitz· May 8

Yes, new leaders are coming, but this declaration indicates a willful disregard for facts and a sign that NASEM is more interested in signaling that it will play ball rather than address cuts to funding, loss of programs and people, and the dismantling of independence in agencies.

Email text from NASEM: "Since McNutt delivered her 2025 address, federal funding for science has held steady, but significant cuts are still being considered. Meanwhile, the race for global dominance in science and technology continues to accelerate — especially in artificial intelligence and quantum computing."

Joshua Weitz@joshuasweitz· May 8

Explain the steady funding and cuts being considered to the more than 25,000 experts no longer working in federal agencies to oversee, perform, and enable R&D: www.nature.com/immersive/d4...

20% reductions of staffing across science agencies.

https://www.nature.com/immersive/d41586-026-00088-9/index.html

Joshua Weitz@joshuasweitz· May 8

Explain the steady funding and cuts being considered to anyone who has applied for a NIH R01 grant. Top-scored grants with 10% percentile used to be nearly certain to be funded. Now? A coin flip. joshuasweitz.substack.com/p/moving-the...