A Bit More Detail

Assorted Personal Notations, Essays, and Other Jottings

[LINK] On genetic studies revealing patterns of Bantu migration in Africa

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The Dragon’s Tales linked to a paper using DNA studies to trace the historic migrations of Bantu peoples across southern and eastern Africa. “Genetic variation reveals large-scale population expansion and migration during the expansion of Bantu-speaking peoples” by Li, Schlebusch and Jakobsson seems to confirm the theories of some linguists.

The majority of sub-Saharan Africans today speak a number of closely related languages collectively referred to as ‘Bantu’ languages. The current distribution of Bantu-speaking populations has been found to largely be a consequence of the movement of people rather than a diffusion of language alone. Linguistic and single marker genetic studies have generated various hypotheses regarding the timing and the routes of the Bantu expansion, but these hypotheses have not been thoroughly investigated. In this study, we re-analysed microsatellite markers typed for large number of African populations that—owing to their fast mutation rates—capture signatures of recent population history. We confirm the spread of west African people across most of sub-Saharan Africa and estimated the expansion of Bantu-speaking groups, using a Bayesian approach, to around 5600 years ago. We tested four different divergence models for Bantu-speaking populations with a distribution comprising three geographical regions in Africa. We found that the most likely model for the movement of the eastern branch of Bantu-speakers involves migration of Bantu-speaking groups to the east followed by migration to the south. This model, however, is only marginally more likely than other models, which might indicate direct movement from the west and/or significant gene flow with the western Branch of Bantu-speakers. Our study use multi-loci genetic data to explicitly investigate the timing and mode of the Bantu expansion and it demonstrates that west African groups rapidly expanded both in numbers and over a large geographical area, affirming the fact that the Bantu expansion was one of the most dramatic demographic events in human history.

Written by Randy McDonald

September 20, 2014 at 2:00 am

[BLOG] Some Friday links

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  • Antipope Charlie Stross wrote last night about the political consequences of the Scottish referendum.
  • blogTO notes that east-end strip joint Jilly’s could become a boutique hotel and restaurant combo much like the Drake.
  • Centauri Dreams reviews the discovery of Pluto’s moon Hydra.
  • Engage with Crooked Timber‘s open thread on the Scottish referendum if you wish.
  • The Dragon’s Gaze links to a paper predicting the existence of an exoplanet, Kepler-47d.
  • The Dragon’s Tales shares the story of how Soviet space station Salyut 7 was saved by two cosmonauts.
  • Geocurrents notes the unreal claims of the Islamic State.
  • Joe. My. God. shares the story of the lesbian couple in Iowa together for 82 years before marrying.
  • The Lawyers, Guns and Money discussion on the consequences of the Scottish referendum is noteworthy.
  • Marginal Revolution notes that the Irish economy is starting to see faster growth now.
  • Torontoist notes that Doug Ford has launched his campaign website.
  • Towleroad shares the story of San Francisco supervisor Scott Wiener who has announced that he takes PrEP.
  • Window on Eurasia suggests Russia is set on an Argentine-like trajectory of missed growth and calls for more attention to the plight of Crimean Tatars.
  • Zero Geography’s Mark Graham maps the pre-referendum Scottish presence on social networks.

[URBAN NOTE] “Strategists for Soknacki and Stintz throw support behind Tory”

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CP24 reports. It looks like this campaign is John Tory’s to lose now.

Earlier on Friday, two key strategists who worked on the campaigns for Karen Stintz and David Soknacki threw their support behind Tory.

Tory welcomed Stintz’s campaign chair Paul Brown and Soknacki’s adviser Gordon Chong outside city hall Friday morning, but did not specify the exact roles they will play on his campaign.

“To me this is important evidence of the fact that we are gaining momentum and that we are gaining new people to our cause to bring the city together and to create one Toronto,” Tory said. “I am just very happy to have them show this gesture of confidence in me, our campaign and perhaps more importantly what this campaign is about.”

Chong, a former councillor, was a member of Mayor Rob Ford’s transition team when he was elected in 2010 and authored a 2012 report on how to fund transit expansion in Toronto titled “Toronto Transit: Back on Track.”

In that report, Chong advocated parking taxes or levies and a special regional sales tax to pay for new infrastructure. On Friday, however, he told reporters that he believes Tory can in fact follow through on his SmartTrack proposal using Tax Increment Financing.

Under TIF, a government borrows money to fund the cost of a project and then pays it back using additional tax revenue generated by higher property values and increased development.

Written by Randy McDonald

September 19, 2014 at 8:08 pm

[URBAN NOTE] “Glasgow gives full backing to Scottish independence”

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The Scotsman reports on one thing I found interesting in yesterday’s referendum in Scotland, on the majority support for independence in Glasgow in its area. Three of the four ridings in Scotland that returned majority support were in the Glasgow urban area. Some speculation I’ve seen elsewhere suggests that the scale of Thatcher-era economic collapse helped create this upset with the British state.

With three quarters of registered adults in Glasgow voting – a turnout of 75% – the Yes campaign won by 53.5% to 46.5% of votes for No.

All of the city’s eight Scottish Parliament constituencies favoured Yes. Although the result did not change the national picture, it represented a significant blow for Glasgow’s Labour-led local authority and Johann Lamont, the leader of Scottish Labour.

[. . .]

In Glasgow, 363,664 votes were cast. In some wards, the Yes vote was conclusive, with a majority of nearly six thousand in Maryhill and Springburn and Glasgow Provan, results that will give Labour politicians in the city much cause for concern.

Although the turnout was lower than other parts of the country, it still made electoral history in the city. In the 1997 referendum on Scottish devolution, the region recored an unenviable turnout of just 51.2%, the lowest of any local authority and well under the national average of 60.2%.

On the ground yesterday, numerous polling stations across the city’s boundaries reported lengthy queues when they opened at 7am. One, in the southside area of Battlefield, reported 150 votes cast in the first 10 minutes. Throughout the day, the turnout remained very high, with the vast logistical operation seeming to run smoothly. In all, there were 438 polling stations in 200 buildings across the city, with 1,188 staff on hand.

Given the size of its population, the largest count in the country was expected to play have an influential bearing on proceedings. In the end, it was good news for Yes, but it came too late to bolster a flagging campaign, although it will likely cause tremors in Glasgow’s political landscape for some time to come.

Written by Randy McDonald

September 19, 2014 at 8:03 pm

[LINK] On the upcoming landing of the Rosetta lander on comet 67P/Churyumov–Gerasimenko

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I’ve come across two interesting articles about the impending landing of Rosetta‘s lander on its target comet.

From National Geographic News, “Landing Site Chosen for Spacecraft’s Daring Rendezvous With Comet”.

Scientists announced Monday morning the spot where a small robot will touch down on the surface of a comet, in what they hope will be the first soft landing on a comet, as opposed to a crash landing.

When the European Space Agency’s Rosetta spacecraft arrived at comet 67P/Churyumov-Gerasimenko this summer after a ten-year journey, scientists realized that landing on the lumpy chunk of ice and rock would be trickier than originally thought.

After a survey for sites that was a complex game of pin-the-lander-on-the-comet, the decision announced Monday is considered the best among the challenging options for setting down the probe, called Philae, on the comet’s craggy surface.

“There is flat area, but there is also some rough terrain,” Stephan Ulamec, Philae lander manager at the German Aerospace Center, says about the site. “It’s not a perfectly flat area as we probably would have hoped for a safe landing site.”

Called site J (for now), the selected landing area presents an added hazard: It’s near two active, gassy pits.

If all goes well, the lander will touch down somewhere inside a one-kilometer-wide target ellipse later this fall. The team has also selected a backup site in case site J loses its luster over the next months, as more high-resolution images come in.

Next, Universe Today’s “Comet’s Head Selected as Landing Site for Rosetta’s Historic Philae Lander”.

After weeks of detailed study and debate focused on balancing scientific interest with finding a ‘technically feasible’ and safe Philae touchdown site, the team chose a target dubbed Site J as the primary landing site from among a list of five initially selected sites, said Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center, at the briefing.

“Site J is the primary landing site around the head of the comet,” Ulamec announced.

“Site C is the backup site on the body [near the bottom of the comet].”

“This was not an easy task. Site J is a mix of flat areas and rough terrain. It’s not a perfectly flat area. There is still risk with high slope areas.”

He also made clear that there is still some landing uncertainty with the targeting of the lander onto the comet.

Site J is an intriguing region on Comet 67P/Churyumov–Gerasimenko that offers unique scientific potential, with hints of activity nearby, and minimum risk to the lander compared to the other candidate sites, according to ESA.

Written by Randy McDonald

September 19, 2014 at 7:57 pm

Posted in Science

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[LINK] “The Mathematics of Ebola Trigger Stark Warnings: Act Now or Regret It”

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Terrible news about the prospects for Ebola in West Africa, as reported by Wired‘s Maryn McKenna.

The Ebola epidemic in Africa has continued to expand since I last wrote about it, and as of a week ago, has accounted for more than 4,200 cases and 2,200 deaths in five countries: Guinea, Liberia, Nigeria, Senegal and Sierra Leone. That is extraordinary: Since the virus was discovered, no Ebola outbreak’s toll has risen above several hundred cases. This now truly is a type of epidemic that the world has never seen before. In light of that, several articles were published recently that are very worth reading.

The most arresting is a piece published last week in the journal Eurosurveillance, which is the peer-reviewed publication of the European Centre for Disease Prevention and Control (the EU’s Stockholm-based version of the US CDC). The piece is an attempt to assess mathematically how the epidemic is growing, by using case reports to determine the “reproductive number.” (Note for non-epidemiology geeks: The basic reproductive number — usually shorted to R0 or “R-nought” — expresses how many cases of disease are likely to be caused by any one infected person. An R0 of less than 1 means an outbreak will die out; an R0 of more than 1 means an outbreak can be expected to increase. If you saw the movie Contagion, this is what Kate Winslet stood up and wrote on a whiteboard early in the film.)

The Eurosurveillance paper, by two researchers from the University of Tokyo and Arizona State University, attempts to derive what the reproductive rate has been in Guinea, Liberia and Sierra Leone. (Note for actual epidemiology geeks: The calculation is for the effective reproductive number, pegged to a point in time, hence actually Rt.) They come up with an R of at least 1, and in some cases 2; that is, at certain points, sick persons have caused disease in two others.

You can see how that could quickly get out of hand, and in fact, that is what the researchers predict. Here is their stop-you-in-your-tracks assessment:

In a worst-case hypothetical scenario, should the outbreak continue with recent trends, the case burden could gain an additional 77,181 to 277,124 cases by the end of 2014.

The Eurosurveillance paper is here.

Written by Randy McDonald

September 19, 2014 at 7:49 pm

[LINK] “Japan to Resume Whaling Next Year, Defying International Whaling Commission”

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Oh, Japan. From National Geographic News:

Japan announced Thursday that it will restart its scientific whaling program next year in response to a new resolution adopted by the International Whaling Commission placing stricter regulations on scientific whaling.

This new nonbinding resolution—proposed by New Zealand—adopts the criteria used by the UN’s International Court of Justice earlier this year when it ruled that Japan’s current whaling program was not scientific.

The new guidelines establish criteria for the International Whaling Commission’s (IWC) scientific committee to consider when it reviews whaling plans submitted by member countries. The criteria include consideration of whether a program needs to lethally sample whales to obtain data, how many whales a scientific program will take, and whether the number to be taken is justified.

At this week’s IWC meeting, Japan’s representatives stated the country’s intention to revamp its scientific program based on “international law and scientific evidence.” They planned to submit their proposed program to the IWC’s scientific committee this fall, with the aim of conducting scientific whaling next year.

If Japan were to abide by the new regulations, the country would have to submit a plan to the scientific committee next year, delaying the start of its whaling activities until 2016, says Leigh Henry, a senior policy adviser for wildlife conservation with the World Wildlife Fund (WWF) in Washington, D.C.

Written by Randy McDonald

September 19, 2014 at 7:42 pm


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