Posts Tagged ‘mathematics’

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Paperscape: A map of 871,888 scientific papers from the arXiv until today

September 11, 2013

A chart of 870,000 scientific studies so far. Paperscape shows each scientific paper as a circle, with the size of each determined by how many others cite it. Users can toggle the heat map, which colors each study according to its age. ArXiv began in 1991. A cluster around the topic dark energy shows that it spans multiple fields, including quantum cosmology, quantum physics, and condensed matter.

The study of the universe is a universe itself. An infographic designed by two physicists maps the hundreds of thousands of studies in arXiv, an open repository for physics, mathematics, computer science, quantitative biology, finance, and statistics papers that is maintained by Cornell University. The category of a paper’s research determines the color of its circle, and the more cited the paper is, the bigger its circle. Each marker is placed according to the number of references it takes to get from it to each other paper. Accordingly, papers are clustered around topics, such as extrasolar planets, dwarf stars, and superconductivity. Some multicolored clusters show where disciplines intersect around topics like neutrinos, dark matter, dark energy, and networks. Toggle the heat map to color each study according to its age to see which topics are getting the most attention. To learn more about how the infographic works, see its blog.

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Plants perform molecular maths

July 9, 2013

As if making food from light were not impressive enough, it may be time to add another advanced skill to the botanical repertoire: the ability to perform — at least at the molecular level — arithmetic division.

Computer-generated models published in the journal eLife illustrate how plants might use molecular mathematics to regulate the rate at which they devour starch reserves to provide energy throughout the night, when energy from the Sun is off the menu. If so, the authors say, it would be the first example of arithmetic division in biology.

But it may not be the only one: many animals go through periods of fasting — during hibernations or migrations, for example — and must carefully ration internal energy stores in order to survive. Understanding how arithmetic division could occur at the molecular level might also be useful for the young field of synthetic biology, in which genetic engineers seek standardized methods of tinkering with molecular pathways to create new biological devices. Text and Image via NATURE. Continue THERE

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OWEN SCHUH

February 5, 2013

OWEN SCHUH: “Through research and experimentation I choose mathematical functions that model the interactions and structure of living systems. Cellular Automata, circle packing, fractals and other topics in discrete mathematics form the basis of my work. These functions bear the structure of life, but operate in the parallel world of the mind: a world of simulacra inhabited by numbers and abstract relationships. The mathematical formula is a virus that depends on a host to carry out its peculiar kind of life until it terminates or the medium or the artist is exhausted. In the end the painting is really only the physical trace of this activity – a shell left behind on the beach.”

Continue HERE

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Wittgenstein’s Master: Frank Ramsey, the genius who died at 26

January 28, 2013

Frank Ramsey was 26 years old when he died after an operation at Guy’s Hospital in January 1930. In his short life, he had made lasting contributions to mathematics, economics and philosophy, and to the thinking of a number of his contemporaries, including Ludwig Wittgenstein.

When I taught at St Anne’s, Oxford during the 1980s, I was introduced by my colleague Gabriele Taylor to Ramsey’s sister, Margaret Paul, by then retired from teaching economics at Lady Margaret Hall college. As with anyone with some knowledge of the fields of enquiry Ramsey influenced, I was immediately recruited into helping with her research into his life and thought, though in a minor capacity; she had a formidable array of other helpers besides, from eminent philosophers like Taylor and PF Strawson onwards.

Frank Ramsey was 18 when Margaret was born, so her own memories of him were those of a little girl. A large part of her motivation in writing about him was to get to know him. In this quest she was equally tireless and scrupulous. Most aspects of his work require advanced technical competence, but she was determined to understand them; an afternoon at her house talking about him could be as gruelling as it was educative.

Excerpt from an article written by Margaret Paul. Continue HERE

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Turning Scientific Perplexity into Ordinary Statistical Uncertainty

June 4, 2012



To show how statistical models are built, the authors of Principles of Applied Statistics use a study on the relation between diabetes control and efforts to explain the disease to patients. The relevant variables (a) are baseline variables such as education, gender and duration of disease; attribution (how individuals conceive their responsibility in managing and treating the disease); knowledge about the disease; and the outcome, a measure of how successfully individuals control glucose levels. Defining the relation between each pair of variables creates a regression chain, a sequence in which the variables in a given box depend on all those in the preceding boxes. After analyzing the data, a simpler version (b) can be proposed: Control of glucose levels depends on knowledge about the disease, which depends on baseline variables; baseline variables also affect glucose control directly. Probability, the authors write, “is used to represent, possibly in highly idealized form, a phenomenon in the real world. As such it is not essentially different from concepts like mass, force and energy.”

D. R. Cox published his first major book, Planning of Experiments, in 1958; he has been making major contributions to the theory and practice of statistics for as long as most current statisticians have been alive. He is now in a reflective phase of his career, and this book, coauthored with the distinguished biostatistician Christl A. Donnelly, is a valuable distillation of his experience of applied work. It stands as a summary of an entire tradition of using statistics to address scientific problems.

Excerpt from an text by Cosma Shalizi, at American Scientist. Continue HERE

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Divine Machines: Leibniz and the Sciences of Life

May 25, 2012

“It is widely recognized that Leibniz’s philosophical thought is deeply influenced by the mathematics, physics and philosophical theology of his era. Justin E. H. Smith’s Divine Machines argues that many of Leibniz’s most central philosophical doctrines are similarly bound up with the life sciences of his time, where the “life sciences” are understood very broadly to include fields as diverse as alchemy, medicine, taxonomy, and paleontology. Smith’s groundbreaking exploration represents an important contribution to our understanding of both Leibniz’s philosophy and the study of life in the early modern era. It is to be recommended to historians, philosophers, and historians of philosophy alike. Below I highlight four central topics in Smith’s book, raising some reservations along the way.”

A review of Justin E. H. Smith’s Divine Machines: Leibniz and the Sciences of Life by Jeffrey K. McDonough. Read it HERE

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A Mathematical Challenge to Obesity

May 16, 2012

Carson C. Chow deploys mathematics to solve the everyday problems of real life. As an investigator at the National Institute of Diabetes and Digestive and Kidney Diseases, he tries to figure out why 1 in 3 Americans are obese.

We spoke at the recent annual meeting of the American Association for the Advancement of Science, where Dr. Chow, 49, gave a presentation on “Illuminating the Obesity Epidemic With Mathematics,” and then later by telephone; a condensed and edited version of the interviews follows.

You are an M.I.T.-trained mathematician and physicist. How did you come to work on obesity?

In 2004, while on the faculty of the math department at the University of Pittsburgh, I married. My wife is a Johns Hopkins ophthalmologist, and she would not move. So I began looking for work in the Beltway area. Through the grapevine, I heard that the N.I.D.D.K., a branch of the National Institutes of Health, was building up its mathematics laboratory to study obesity. At the time, I knew almost nothing of obesity.

I didn’t even know what a calorie was. I quickly read every scientific paper I could get my hands on.

I could see the facts on the epidemic were quite astounding. Between 1975 and 2005, the average weight of Americans had increased by about 20 pounds. Since the 1970s, the national obesity rate had jumped from around 20 percent to over 30 percent.

The interesting question posed to me when I was hired was, “Why is this happening?”

Excerpt from an interview/article written by CLAUDIA DREIFUS, NYT. Continue HERE