Archive for ants

radioactive ant fiction [in J. Hymenoptera Research]

Posted in Books, Kids, pictures, University life with tags , , , , , , , , , on November 30, 2019 by xi'an

Following a link in Nature, I read a short communication in the Journal of Hymenoptera Research [which I confess I rarely peruse!], which sounded more like a B movie from the 1950s than a scientific article. Starting with the title “Ants trapped for years in an old bunker; survival by cannibalism“! (This is actually the second episode in the series.) While the bunker was intended for storing Soviet nuclear weapons, no radioactivity impacted on the ants and they (the colony) survived in the dark at the bottom of the bunker for 22 years, with no source of food but their own, with new ants falling into the bunker on a regular basis. Hence the title. What I found most surprising in the paper is the fact that it is a sheer description of an observation (with field pictures) and of an intervention (we set a 3m vertical boardwalk to allow for escape) that reminded me more of my childhood fascination with ants (involving radical interventions) than of a typical science paper!

lords of the rings

Posted in Books, pictures, Statistics, University life with tags , , , , , , on February 9, 2017 by xi'an

In the 19 Jan 2017 issue of Nature [that I received two weeks later], a paper by Tarnita et al discusses regular vegetation patterns like fairy patterns. While this would seem like an ideal setting for point process modelling, the article does not seem to get into that direction, debating instead between ecological models. Which combines vegetal self-organisation, with subterranean insect competition. Since the paper seems to derive validation of a model by simulation means without producing a single equation, I went and checked the supplementary material attached to this paper. What I gathered from this material is that the system of differential equations used to build this model seems to be extrapolated by seeking parameter values consistent with what is known” rather than estimated as in a statistical model. Given the extreme complexity of the resulting five page model, I am surprised at the low level of validation of the construct, with no visible proof of stationarity of the (stochastic) model thus constructed, and no model assessment in a statistical sense. Of course, a major disclaimer applies: (a) this area does not even border my domains of (relative) expertise and (b) I have not spent much time perusing over the published paper and the attached supplementary material. (Note: This issue of Nature also contains a fascinating review paper by Nielsen et al. on a detailed scenario of human evolutionary history, based on the sequencing of genomes of extinct hominids.)

Le Monde and the replication crisis

Posted in Books, Kids, Statistics with tags , , , , , , , , , , , , , , , on September 17, 2015 by xi'an

An rather poor coverage of the latest article in Science on the replication crisis in psychology in Le Monde Sciences & Medicine weekly pages (and mentioned a few days ago on Andrew’s blog, with the terrific if unrelated poster for Blade Runner…):

L’étude repose également sur le rôle d’un critère très critiqué, la “valeur p”, qui est un indicateur statistique estimant la probabilité que l’effet soit bien significatif.

As you may guess from the above (pardon my French!), the author of this summary of the Science article (a) has never heard of a p-value (which translates as niveau de signification in French statistics books) and (b) confuses the probability of exceeding the observed quantity under the null with the probability of the alternative. The remainder of the paper is more classical, pointing out the need for preregistered protocols in experimental sciences. Even though it mostly states evidence, like the decrease in significant effects for prepublished protocols. Apart from this mostly useless entry, rather interesting snapshots in the issue: Stephen Hawking’s views on how information could escape a black hole, an IBM software for predicting schizophrenia, Parkinson disease as a result of hyperactive neurons, diseased Formica fusca ants taking some harmful drugs to heal, …