标签：#Science

Neanderthals had some wild stuff in their toolkits.

The National Center for Atmospheric Research won't be losing its supercomputer.

Microsoft claimed last year that it had made a key breakthrough in quantum computing with Majorana 1, the company's first quantum processor. While physicists were immediately skeptical of Microsoft's claims, the software giant is announcing Majorana 2 today, the next generation of its topological quantum chip. Majorana 2 contains qubits, a unit of information in […]

There are sound engineering reasons to use the same approach SpaceX uses with the Falcon 9.

Prehistoric mining in the Pyrenees, a new species of tiny blue octopus, slapstick acoustics, and more.

This article was originally published on davidohnstad.com . I cross-post here to reach the Dev.to community. { " @context ": " https://schema.org ", " @graph ": [ { "@type": "Person", " @id ": " https://davidohnstad.com/#author ", "name": "David Ohnstad", "url": " https://davidohnstad.com ", "sameAs": [ " https://www.linkedin.com/in/davidohnstad/ ", " https://orcid.org/0009-0007-9023-7456 ", " https://davidohnstad5.mystrikingly.com/ ", " https://github.com/davidohnstad40-netizen ", " https://hashnode.com/@davidohnstad ", " https://davidohnstad.com ", " https://davidohnstad.net ", " https://davidohnstad.info ", " https://david-ohnstad.com ", " https://davidohnstadminnesota.com " ], "jobTitle": "Senior Data Product Manager", "worksFor": { "@type": "Organization", "name": "Veeam Software", "url": " https://www.veeam.com " }, "alumniOf": { "@type": "CollegeOrUniversity", "name": "College of St. Scholastica" }, "address": { "@type": "PostalAddress", "addressLocality": "Duluth", "addressRegion": "MN", "addressCountry": "US" }, "description": "Senior Data Product Manager at Veeam Software, MS and MBA from the College of St. Scholastica, based in Duluth, Minnesota. Specializes in data architecture, AI/ML integrations, and SaaS platform development." }, { "@type": "Article", " @id ": " https://davidohnstad.com/data-product-manager-org-structure-reporting#article ", "headline": "Data Product Manager Org Structure: Reporting Lines That Matter", "description": "David Ohnstad reveals where data product managers actually fit in org charts and why reporting lines determine success. Real insights from a data PM restructure.", "url": " https://davidohnstad.com/data-product-manager-org-structure-reporting ", "datePublished": "2026-05-29T14:06:18Z", "dateModified": "2026-05-29T14:06:18Z", "author": { "@type": "Person", " @id ": " https://davidohnstad.com/#author " }, "publisher": { "@type": "Organization", "name": "David Ohnstad", "url": " https://davidohnstad.com ", "logo": { "@type"

Though Gen Z has developed a reputation for being so disinterested in sex that they don't even want to see it on TV, the popularity of series like Heated Rivalry and The Summer I Turned Pretty has made it very clear that more than a few young people do, in fact, like their entertainment a […]

Introduction In contemporary research, the volume of biological data deposited in public repositories is growing exponentially. The Gene Expression Omnibus (GEO), NCBI Gene, PubMed, and UniProt accumulate thousands of new records daily, including sequences, expression profiles, scientific articles, and functional annotations. On the one hand, this scenario represents a unique opportunity for biomedical research. On the other hand, the diversity of data formats, access protocols, and metadata models creates a significant barrier: each source requires a specific collector, distinct rate-limiting strategies, and its own validation logic. Above all, the lack of standardization in data storage compromises the reproducibility of scientific studies. The need for integrated tools capable of unifying data extraction, curation, and persistence has been widely discussed. In practice, ad hoc solutions such as isolated scripts for individual repositories generate redundant work and make maintenance difficult. First and foremost, it is necessary to establish an architecture that treats data collection as a service rather than a collection of scattered artifacts. This work presents Project 1 of the Integrated Bioinformatics Platform: a containerized Biomedical Data Collector coupled with a Data Lake. Its objective is to provide a REST API capable of triggering asynchronous data collections from the four aforementioned sources, storing immutable raw data in MinIO, and persisting metadata in PostgreSQL, all while ensuring traceability and resilience. Development The system architecture is divided into three main layers. The first is the API and orchestration layer , implemented using FastAPI. Its five endpoints — POST /collections , GET /collections , GET /collections/{id} , GET /collections/{id}/download/{dataset_id} , and GET /health — expose a clean interface for initiating and monitoring collection processes. The second layer is the collector engine , composed of abstract classe

I tried to explain OpenAI’s solution more clearly than OpenAI did.

Sellers of products with names like Boner Bears and DTF have voluntarily recalled their products after testing positive for the active ingredients in Viagra and Cialis.

There might finally be a way forward for long Covid treatment—if only you were allowed to talk about it.

A flanged pipe joint looks simple: two raised faces, a gasket between them, a ring of bolts pulling them together. Yet the gasketed bolted flange is one of the most common sources of leaks in process plants, and the reason is almost always the same — the bolts were not tightened to the right load. Too little and the joint weeps; too much and the gasket is crushed. The number that sits between those failures is the bolt preload, and it is not the same as the pressure load. This article explains how a bolted flange actually carries internal pressure, why the bolts must be preloaded well above the pressure end force, works a concrete example, and lists the mistakes that turn a sound joint into a leaking one. Why this calculation matters Bolted flange joints appear wherever a pipe or vessel has to be opened for maintenance: pump connections, valve bodies, heat exchanger shells, instrument tappings, and reactor manways. Unlike a welded joint, a flange is meant to be taken apart and reassembled, and every reassembly depends on the fitter applying the correct bolt load. The stakes are real. A leaking flange on a hazardous service can release flammable or toxic fluid. Even a benign leak wastes product and forces an unplanned shutdown. Design codes such as ASME Section VIII Appendix 2 set out a full method for sizing flange bolts, and at its heart is a comparison: the load the bolts can supply versus the load the joint demands in two distinct conditions — seating the gasket, and holding pressure. Understand the pressure end force and you understand the floor that the bolt load must clear. The core method When the line is pressurised, internal pressure acts on the fluid inside the flange and pushes the two flanges apart. The total separating force is the hydrostatic end force , the pressure acting over the area enclosed by the gasket sealing circle: H = p * (pi / 4) * G^2 Here p is the internal pressure and G is the gasket reaction (sealing) diameter — the effective circle on

In This Article The Question The Intuition Trap Building the State Machine for HH Solving the System: E[HH] = 6 Building the State Machine for HTH Solving the System: E[HTH] = 10 Why Overlapping Patterns Change Everything Python Simulation: 100,000 Trials Business Application: Credit Migration & Web Ranking The Question You flip a fair coin — one with probability 1/2 of landing heads and 1/2 of landing tails — repeatedly, recording every result. What is the expected number of flips required until the sequence HH appears for the first time as consecutive results? What is the expected number of flips required until HTH appears for the first time? Both questions have the same surface structure: you want a specific consecutive pattern, and you want to know, on average, how many flips it takes to observe it. The coin is fair, the flips are independent, and the patterns are short. These seem like they should yield similar answers. They do not. HH takes exactly 6 flips on average. HTH takes exactly 10. The four-flip gap between those two answers is not a rounding artifact or a computational error — it is a precise consequence of the internal structure of each pattern, and deriving it rigorously is one of the cleanest demonstrations of absorbing Markov chain analysis you will encounter. This problem appears frequently in quantitative finance interviews — at firms like Jane Street, Citadel, and Two Sigma — precisely because it separates candidates who understand Markov structure from those who rely on heuristic reasoning. Getting the answer right, and being able to explain it, requires building a state machine, writing the system of first-step equations, and solving it algebraically. That is exactly what we will do. The Intuition Trap Before the formal derivation, it is worth examining why intuition fails here. The most common wrong answer from candidates is that both expected values should be "similar" because the patterns are comparable in length. This intuition imports th

On Saturday, at around 2:06 pm ET, a meteor streaked over the northeastern US and exploded north of Cape Cod Bay. The fireball was caught on camera by several people, shook houses, and can even be seen clearly in satellite imagery, lighting up the sky. Some residents initially thought that the shaking and boom may […]

As temperatures rise, some creatures pick fights while others struggle to learn.

From specialized motors to the use of machine learning algorithms, Turkey’s billion-dollar hair-transplant industry is the result of a constant process of innovation.

A crack in an aircraft window, a fracture starting at a bolt hole, a shaft that snaps at the shoulder where the diameter steps down. These failures share a cause that has nothing to do with the average load the part carries. The metal broke because a change in geometry concentrated stress into a tiny region, and that local peak — not the nominal stress — drove the crack. This article explains the stress concentration factor: what it means, where the classic value of 3.0 comes from, how to apply it, and the mistakes that make engineers underestimate the danger of an innocent-looking hole. Why this calculation matters Real parts are not smooth bars. They have holes for fasteners, fillets where sections change, keyways, grooves, threads, and shoulders. Every one of those features disturbs the flow of stress through the material. Where the lines of force have to bend around an obstacle, they crowd together, and the local stress climbs well above the value you would compute from force divided by area. The stress concentration factor, K_t, is the multiplier that captures this. It matters most for two failure modes. Under static loading of a brittle material, the peak stress can trigger fracture before the bulk of the section yields. Under cyclic loading, the concentrated stress is where fatigue cracks nucleate — and the vast majority of fatigue failures begin at a geometric discontinuity. If you size a part on nominal stress alone and ignore K_t, you have skipped the step where most failures are actually decided. The core formula The stress concentration factor is defined as a simple ratio: K_t = sigma_max / sigma_nom Here sigma_max is the true peak stress at the discontinuity and sigma_nom is the nominal stress computed from elementary mechanics. The subscript t means "theoretical" — K_t depends only on geometry and loading mode, not on the material. It comes from elasticity theory, finite element analysis, or experiment, and it assumes the material is still behaving ela

A new book looks into the long history of people who have opposed vaccines.

A walk in the cemetery led to Cornell researchers discovering an underground colony of bees with an estimated population of 5.5 million—one of the largest ever recorded.

The activewear giant has used chemical recycling to make jersey for 16 teams competing in the tournament. But the technique is unlikely to help solve fashion’s waste issue.