science tidbits

Several interesting entries in Le Monde Science & Médecine of this week (24 Jan 2018):

1. This incredible report in the Journal of Ethnobiology of fire-spreading raptors, Black Kite, Whistling Kite, and Brown Falcon, who carry burning material to start fires further away and thus expose rodents and insects. This behaviour was already reported in some Aboriginal myths, as now backed up by independent observations.
2. A report by Etienne Ghys of the opening of a new CNRS unit in mathematics in… London! The Abraham de Moivre Laboratory is one of the 36 mixed units located outside France to facilitate exchanges and collaborations. In the current case, in collaboration with Imperial. And as a mild antidote to Brexit and its consequences on exchanges between the UK and the EU. (When discussing Martin Hairer’s conference, Etienne forgot to mention his previous affiliation with Warwick.)
3. A good-will-bad-stats article on the impact of increasing the number of urban bicycle trips to reduce the number of deaths. With the estimation that if 25% of the daily trips over 167 European (and British!) cities were done by bike, 10,000 deaths per year could be avoided! I have not read the original study, but I wonder at the true impact of this increase. If 25% of the commutes are made by bike, the remaining 75% are not and hence use polluting means of transportation. This means more citizens travelling by bike are exposed to the exhausts and fumes of cars, buses, trucks, &tc. Which should see an increase in respiratory diseases, including deaths, rather than a decrease. Unless this measure is associated with banning all exhaust emissions from cities, which does not sound a very likely outcome, even in Paris.
4. An incoming happening at Cité internationale des Arts in Paris, on Feb 2-3, entitled “we are not the number we believe we are” (in French), based on the universe(s) of Ursula Le Guin who most sadly passed away the day the journal came out.
5. A diffusion of urban riots in the suburbs of Paris in 2005 that closely follows epidemiological models of flu epidemics, using “a single sociological variable characterizing neighbourhood deprivation”. (Estimation of the SIR model is apparently done by maximum likelihood and model comparison by AIC, given the ODE nature of the models, ABC would have been quite appropriate for a Bayesian modelling!)

Nature highlights

A mostly genetics issue of Nature this week (of October 13), as the journal contains an article on the genomes of 300 individuals from 142 diverse populations across the globe, and another one on the genetic history of Australia Aborigines, plus a third one of 483 individuals from 125 populations drawing genetic space barriers, leading to diverging opinions on the single versus multiple out-of-Africa scenario. As some of these papers are based on likelihood-based techniques, I wish I had more time to explore the statistics behind. Another paper builds a phylogeny of violence in mammals, rising as one nears the primates. I find the paper most interesting but I am not convinced by the genetic explanation of violence, in particular because it seems hard to believe that data about Palaeolithic, Mesolithic, and Neolithic periods can be that informative about the death rate due to intra-species violence. And to conclude on a “pessimistic” note, the paper that argues there is a maximum lifespan for humans, meaning that the 122 years enjoyed (?) by Jeanne Calment from France may remain a limit. However, the argument seems to be that the observed largest, second largest, &tc., ages at death reached a peak in 1997, the year Jeanne Calment died, and is declining since then. That does not sound super-convincing when considering extreme value theory, since 1997 is the extreme event and thus another extreme event of a similar magnitude is not going to happen immediately after.

a bone of contention

“In an age in which ancient genomes can reveal startling links between historical populations, we should ask not just whether remains should be reburied, but who decides and on what grounds.”

An article in Nature described the story of fairly old remains (of the Kennewick Man) in North America that were claimed for reburial by several Native American groups and that were found to be closer [in a genetic sense] to groups that were geographically farther (from South America and even Australian aboriginal Australians). What I find difficult to understand (while it stands at the centre of the legal dispute) is how any group of individuals can advance a claim on bones that are 8,000 year old. With such a time gap (and assuming the DNA analysis is trustworthy) the number of individuals who share the owner of the bones as one ancestor is presumably very large and it is hard to imagine all those descendants coming to an agreement about the management of the said bones. Or even that any descendant has any right on the said bones after so many generations which may have seen major changes in the way deceased members of the community are treated. I am thus surprised that a judiciary court or the US government could even consider such requests.

Flaggermusmannen [book review]

“Cold, concise statistics. Keyword number one is statistical significance. In other words, we are looking for a system that cannot be explained by statistical chance (…) this group constitutes less than five percent of the female population. Yet I was left with seven murders and over forty rapes.” J. Nesbø

Another first novel! The Bat (Flaggermusmannen) by  Jo Nesbø has been sitting in my bedside book pile for quite a while, until I decided to read it a few days ago. It is the first appearance of Inspector Harry Hole in a published book and was written in 1997, although translated into English much much later. (The book was nominated as Best Norwegian Crime Novel of the Year and as Best Nordic Crime Novel of the Year.)

“Life consists of a series of quite improbable chance occurrences (…) What bothers me is that I’ve got that lottery number too many times in a row.” J. Nesbø

I read the (later) novel The Redeemer a few years ago, taking place mostly in Norway and kept a globally positive impression about the book, even though the plot was a bit stretched… The Bat has somewhat the same defects as The Ice Princess in that it sounds too much like an exercise in thriller writing, albeit in a much less clumsy style! The central character of Harry Hole is well-done, in an engaging-despite-his-shortcomings style and the way he gets along with most of the people he meets is rather realistic. However, the setting of the first novel in Australia (rather than Norway) is sort of a failure in that the country and Sydney are more caricatures than realistic in any degree…. For instance, every aboriginal Harry meets must resort to traditional tales involving emus and lizards and other local animals. One such tale would be ok but so many are just a bore. The title itself is connected to yet another aboriginal myth. And to the murders occurring way too often in the novel. Similarly, every foreign backpacker met in the pages of The Bat is either dumb or on her way to become a waitress to recover from a failed love affair. And a major character is a transvestite playing in a theatre, maybe because Nesbø has watched Priscilla Queen of the Desert a few years earlier… And the Australian police officers sound both very heavy in colloquialism and quite light in detective skills. Lacking an obvious connection to a series of young women murders throughout Australia. The second part of the novel gets too artificial to remain gripping and I completed the book with a feeling of chore accomplished…, not of surprise or shock at the resolution of the murders. I thus concur with many other readers of the book that it is certainly far from being the best in the series!

Illywhacker

“My son had a great store of affection he could not give to people properly; he just didn’t have the knack. He could not hug his little sister without awkwardness, but when he confronted this steel-beaked bird his affection issued from him readily, like a net, a finely knotted gauze which the bird felt and stayed still to accept.” — Peter Carey, Illywhacker

Another boat read was Illywhacker, by Peter Carey. I had it sitting in my book pile since my Australia trip in 2008, borrowed from Kerrie Mengersen, and I had never found the opportunity to start it… So much the loss for me! It is indeed an incredible book, a tour de force, a … Something clearly unique, a sort of the Budenbrooks meet Grapes of wrath, a family saga with an extra-dose of epic, a side dish of magical allegory, at least two servings of lies, an undercurrent of unlikely sex scenes, a kaleidoscope of unique characters, a strong flavouring of political criticisms, and, above all, the love of the land and of its inhabitants (except for the aborigenes who are conspicuously missing from the array of characters).

“The autumn rain had turned the landscape green but at six in the evening it was laid over with a rich golden mist; the farmer’s sheep looked like splendid creatures, not the daggy-bummed animals Jack McGrath loathed.” — Peter Carey, Illywhacker

Illywhacker could serve as a history book of 20th century Australia, in its description of the way the origins of its inhabitants melted into a feeling of a nation, against England and not so much against America, not without ambiguities, either, as . In that sense, it also reminded me of Rushdie’s Midnight children. The style is very unique as well, flowing back and forth between the characters and giving them a very strong reality. (In case you wonder, an illywhacker is a small-time confidence trickster or seller of trinkets, in association with the verb “to whack the illy”.) I also like the depiction of the political climate of the 30’s, communists being apparently persecuted in Australia as they were in the US. A must-read!