Archive for March, 2013

Mar 08 2013

Father of Us All

Published by under General Science

Each time a new genetic analysis dates the time to the most recent common ancestor (MRCA) of humans, we get headlines proclaiming that the “mother,” “father,” or “ancestor” of all humanity has been discovered – commonly referred to as “Eve” or “Adam” when the analysis involved mitochondrial or Y-chromosome DNA respectively. I find the reports to usually be at least a bit misleading, which is not unexpected given that the topic is fairly complex.

This is happening again with the recent headlines, “Father of all humankind is 340,000 years old.”

What they are talking about is a new study looking at the Y-chromosome of a particular African American male whose family submitted his DNA for ancestry analysis. It turned out to be a very rare type, and in fact represents an ancient Y-chromosome ancestry. Understanding what this means, however, requires a bit of background.

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Mar 07 2013

Online Illness Early Detection

Published by under Skepticism,Technology

Any intervention that interacts with a large system is bound to have unintended consequences. This concept is often brought up in the context of government – laws are passed to have a certain desired effect but have unintended secondary effects, often in opposition to what was desired.

Technology also can have unforeseen results. It is conventional wisdom, for example, that the invention of the cotton gin, intended to make cotton processing more efficient, also has the consequence of making slaves in much higher demand, leading ultimately to the civil war.

Arguably one of the biggest technological creations of our generation is the internet. It has transformed the way we access information. Predictions as to its utility were all over the place, some fairly accurate in certain respects, others way off.

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Mar 05 2013

HIV Cure “Game Changer”

The story of a young patient apparently cured of HIV infection, making them only the second case of an HIV cure ever, is buzzing around the internet. It is an interesting and important story, but as is often the case the details are complicated and need to be put into context.

The case was recently presented at a conference, on Retrovirus and Opportunistic Infections. The child was born of an HIV infected mother who did not receive pre-natal care. The mother had high viral loads when she presented for delivery. Not surprisingly, the child was found to be infected shortly after birth, indicating that they were likely infected in utero.

Hannah Gay, a pediatric infectious disease specialist, consulted on the case and decided to treat the infant with higher doses of anti-retroviral therapy (ART) than are typically given. She gave therapeutic doses of ART rather than prophylactic (preventive) doses. She also started the ART drugs earlier than they are typically given, at 31 hours of life.

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Mar 04 2013

CAM Practitioners as Primary Care Doctors

Chiropractors and naturopaths would like to be your primary care physician. They are tirelessly lobbying to expand their scope of practice, with the goal of achieving full parity with actual physicians. This would be an unmitigated disaster, for reasons I will detail below.

Oregon is setting up coordinated care organizations to help promote improved care at reduced cost. The idea sounds plausible and is a good experiment in how to reduce health care costs. The idea is to set up local groups of health practitioners who work in a coordinated way to take care of the local population, including physical and mental health, with dental health on the way. These CCOs would focus on preventive care with the goal of reducing illness and ER visits.

With any new health care initiative (including Obamacare, and this CCO initiative) so-called complementary and alternative medicine (CAM) practitioners see them as an opportunity to expand their power, reach, and scope. Unfortunately they have been largely successful – they know how to talk to both ends of the political spectrum, and the relevant science seems to get lost or distorted in all the propaganda.

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Mar 01 2013

Bicycle Helmets

I received the following question in the topic suggestions page:

I recently got into a debate about the efficacy of bicycle helmets and — as someone who wears a helmet religiously and credits one with once saving me from serious injury — I was amazed to find that the research into this subject is… well, I’m not sure if “messy” or “inconclusive” is the right word:

http://en.wikipedia.org/wiki/Bicycle_helmet#Science:_measuring_helmet_effectiveness

Any insight you could provide into this would be much appreciated.

As with many things, the question is more complex than it may at first appear. It might seem at first that the question is straight-forward – do bicycle helmets work? But what exactly is meant by this? Most people might assume that this means – if you are riding a bicycle and get into an accident, will the helmet reduce the severity of the resulting head injury?

We could, however, ask several other reasonable questions related to using a bicycle helmet:

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