Valentin Ștefan
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veralis.bsky.social
Valentin Ștefan
@veralis.bsky.social
19 followers 26 following 8 posts
Curious about how machine learning and computer vision can reveal patterns in nature. Right now working with computer vision for plant-pollinator monitoring. https://www.linkedin.com/in/valentin-stefan/
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veralis.bsky.social
Excited to share a new paper led by our colleagues at #DLR! We trained AI to recognize 15 European fly pollinator families and estimate how confident it is, helping ecologists use AI more responsibly.
Paper: lnkd.in/dBAWW3hB
Code: lnkd.in/du7dD2hc

#pollinators #aiforgood #aifornature #UFZ #iDiv
October 7, 2025 at 12:42 PM
veralis.bsky.social
Our latest research explores how YOLO object detectors, trained on citizen science images, perform on unseen time-lapse images of pollinators captured with a fixed smartphone setup. While successful for larger pollinators, detecting smaller or blurrier flower visitors remains a challenge.
April 13, 2025 at 6:02 PM
Reposted by Valentin Ștefan
adambonica.bsky.social
The DOGE firings have nothing to do with “efficiency” or “cutting waste.” They’re a direct push to weaken federal agencies perceived as liberal. This was evident from the start, and now the data confirms it: targeted agencies overwhelmingly those seen as more left-leaning. 🧵⬇️
Scatterplot titled “Empirical Evidence of Ideological Targeting in Federal Layoffs: Agencies seen as liberal are significantly more likely to face DOGE layoffs.” • The x-axis represents Perceived Ideological Leaning of federal agencies, ranging from -2 (Most Liberal) to +2 (Most Conservative), based on survey responses from over 1,500 federal executives. • The y-axis shows Agency Size (Number of Staff) on a logarithmic scale from 1,000 to 1,000,000. Each point represents a federal agency: • Red dots indicate agencies that experienced DOGE layoffs. • Gray dots indicate agencies with no layoffs. Key Observations: • Liberal-leaning agencies (left side of the plot) are disproportionately represented among red dots, indicating higher layoff rates. • Notable targeted agencies include: • HHS (Health & Human Services) • EPA (Environmental Protection Agency) • NIH (National Institutes of Health) • CFPB (Consumer Financial Protection Bureau) • Dept. of Education • USAID (U.S. Agency for International Development) • The National Nuclear Security Administration (DOE), despite its conservative leaning (+1 on the scale), is an exception among targeted agencies. • A notable outlier: the Department of Veterans Affairs (moderately conservative) also faced layoffs despite its size. Takeaway: The figure visually demonstrates that DOGE layoffs disproportionately targeted liberal-leaning agencies, supporting claims of ideological bias. The pattern reveals that layoffs were not driven by agency size or budget alone but were strongly associated with perceived ideology. Source: Richardson, Clinton, & Lewis (2018). Elite Perceptions of Agency Ideology and Workforce Skill. The Journal of Politics, 80(1).
February 20, 2025 at 2:18 AM
Reposted by Valentin Ștefan
ibartomeus.bsky.social
[new paper] EuPPollNet: A European Database of Plant-Pollinator Networks
onlinelibrary.wiley.com/doi/10.1111/... Another wonderful paper of @joseblanuza.bsky.social making open more than >1500 networks and looking at their properties. Come for the data, stay for the cool figures!
EuPPollNet: A European Database of Plant‐Pollinator Networks
Motivation Pollinators play a crucial role in maintaining Earth's terrestrial biodiversity. However, rapid human-induced environmental changes are compromising the long-term persistence of plant-pol...
onlinelibrary.wiley.com
February 4, 2025 at 8:01 AM
Reposted by Valentin Ștefan
jpollecol.bsky.social
2025 starts with a methodology publication by Ștefan et al. on Utilising affordable smartphones and open-source time-lapse photography for pollinator image collection and annotation - Happy new year!
doi.org/10.26786/192...
January 10, 2025 at 4:22 PM
veralis.bsky.social
Our research center (iDiv) will host a very interesting summer school (25 – 29 August 2025) - Deep learning for biodiversity and ecological research.
More details here: www.idiv.de/events/summe...

#biodiversity #education #aiforgood #technology #idiv
Summerschool 2025: Deep learning for biodiversity and ecological research | iDiv
www.idiv.de
January 28, 2025 at 12:05 PM
veralis.bsky.social
📢 Excited to share our new paper: "Utilising affordable smartphones and open-source time-lapse photography for pollinator image collection and annotation" 🌼📸
What taxonomists can achieve using only field-captured images from a fixed setup?

🔗 Read it here: www.pollinationecology.org/index.php/jp...
January 13, 2025 at 9:56 AM