April 13, 2018

Briefly

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An ‘insufficient data’ edition

  • Data quality matters: the high rate of death reported for women giving birth in Texas seems to have been partly a data entry error.  Researchers say Approximately half (50.3%) of obstetric-coded deaths showed no evidence of pregnancy within 42 days, and a large majority of these incorrectly indicated pregnancy at the time of death. That is, these were real deaths, but not related to pregnancy. The research paper also says “Texas’ current electronic death registration system displays pregnancy status options as a dropdown list. The “pregnant at the time of death” option is directly below the “not pregnant within the past year” option”  Via Ars Technica.
  • The new cancer drug pembrolizumab (Keytruda) is spectacularly effective across a wide range of tumours, but typically for a minority of patients. In the US, the FDA has approved its marketing for any tumour with a particular defect in DNA repair, but testing for that defect is not as reliable as one would like. The story in Nature News focuses on false negatives: people who would benefit but aren’t found by the test.  In New Zealand, false positives are also important: these new drugs would be more cost-effective and so more likely to be subsidised if you could avoid giving them to people who wouldn’t benefit.
  • There’s a new claim that kumara got to the Pacific Islands before people did, in the New York Times, based on this research. Basically, the DNA from samples collected by the first European botanists in Polynesia has quite a lot of minor differences from modern sweet potatoes in the Americas, suggesting that its ancestors had been separated from the rest of the sweet potato lineage for over 100,000 years.  However, Lisa Matisoo-Smith and Michael Knapp from Otago argue that the samples are old enough — nearly 250 years — that the DNA will have been degraded and needs to be analysed with special obsessively-detailed protocols for old DNA.  That is, the evidence isn’t nearly strong enough to overturn the other reasons for thinking kumara were brought from South America by humans.
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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »

Comments

  • avatar
    Steve Curtis

    The idea that two different languages have a similar word cumar and kumara for the same item is forgetting that both original languages had no written form but have since become romanised.
    There other coincidences too, the Greek theos to the Nahuatl ( an Aztec language) teotl.
    There are other problems with this language matching described in ‘Man Across the Sea: Problems of Pre-Columbian Contacts’, who say the Quechua word for sweet potato is apichu and other words. The DNA researchers are only shaky ground with their language claims.

    6 years ago