Shape of Human Nose Influenced by Climate

The basic function of the human nose is to warm and humidify the air before it reaches the lungs. Because of the wide variation of human habitats from the polar cold and dry air to the equatorial hot and humid weather, one would expect the nose to accommodate to these climate extremes accordingly thru evolutionary pressures.

In essence, logically one would expect the nose to change shape to enhance time that air is in contact with the warm and moist nasal interior in cold and dry climates compared to the opposite environmental extreme.

German scientists evaluated this hypothesis thru 3D modeling of 100 skulls to analyze the shape of the bony nasal cavity of 10 modern human groups living in five different climates and found that the bony nasal cavity appears mostly associated with temperature effects and the nasopharynx with humidity.

Humans living in cold, dry climates tended to have nasal cavities relatively high and long with an abrupt narrowing in the upper nasal cavity than those living in hot, humid climates. Such characteristics enhance contact between the air and the nasal mucosal tissue that helps to warm and humidify that air.

What does such a nose look from the outside? A narrow, longer internal nasal cavity is generally linked to a relatively narrower and more projected nose.

Read a magazine article about this research.

Reference:
Climate-related variation of the human nasal cavity. American Journal of Physical Anthropology. Volume 145, Issue 4, pages 599–614, August 2011

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Link Between Oral Sex and Head & Neck Cancer

USA Today published a pretty accurate article regarding the rise of certain head & neck cancers with the increased popularity of oral sex and number of sexual partners.

The factor that creates this link is the HPV virus which is associated with tonsil and tongue cancer. Alcohol and tobacco use is more highly linked with such oral cancers, but HPV does appear to be an independent risk factor.

A 2007 study in the New England Journal of Medicine found that younger people with head and neck cancers who tested positive for oral HPV infection were more likely to have had multiple vaginal and oral sex partners in their lifetime. Having six or more oral sex partners over a lifetime was associated with a 3.4 times higher risk for oropharyngeal cancer; cancers of the base of the tongue, back of the throat, or tonsils. Having 26 or more vaginal-sex partners tripled the risk. The association continued to increase as the number of partners in either category increased.

Of greater concern is that "French" kissing may also potentially be a mode of transmission.

The good news (if one is a young, non-smoker diagnosed with HPV-positive tumors) is that about 85% of non-smoking people with HPV-positive tumors survive. That number drops to 45 or 50% in people who smoke and are HPV-negative.

Th take-home message here is that even if you are a non-smoker and non-drinker, you can STILL develop head and neck cancer. Oral HPV infection is strongly associated with oropharyngeal cancer among subjects with or without the established risk factors of tobacco and alcohol use and that oral HPV infection can occur through sexual activity.

Furthermore, it is possible that the HPV vaccine (ie, gardasil) may also be protective (studies pending) for both women AND men.

Read the USA Today article here.

References:
Human papillomavirus and oropharyngeal cancer. N Engl J Med. 2007 Sep 13;357(11):1157; author reply 1157-8

Human papillomaviruses in head and neck carcinomas. N Engl J Med. 2007 May 10;356(19):1993-5.

Case-control study of human papillomavirus and oropharyngeal cancer. N Engl J Med. 2007 May 10;356(19):1944-56.

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Simple Rubber Device Mimics Complex Birdsongs & Implications for Human Voice

A team of US researchers at Harvard has developed a simple rubber device composed of two pieces of rubber replicating the 'vocal tract' and a motor that replicates the action of a contracting muscle. With this device, the researchers have been able to EXACTLY mimic the birdsong of a variety of species including the bengalese finches and vireos.

Given complex birdsongs have been faithfully reproduced with such a rudimentary device as shown here, it does suggest that complex neurologically processes are NOT required. In reality, physics is all that is needed with just a little brain power.

You can listen to samples of birdsongs produced by the device here (halfway down the page).

If birdsongs can be replicated with such a simple device, just maybe, better vocal cord devices can be created for humans who have lost the ability to produce a clear voice.

Humans can lose the ability to talk/sing clearly due to cancer, papillomas, scarring, paralysis, etc. Although research on vocal cords is active, I'm not aware of any projects pursuing complete replacement with a biological equivalent of the rubber band. In fact... I'm not aware of any research project being pursued to create the biologic rubber band in the first place.

If you read any textbooks describing the vocal cords, it does seem mind-numbingly complex which perhaps explains why researchers have been discouraged from pursuing this line of inquiry.

But, if it can be done for birdsongs whose vocal cords are anatomically similar to humans, than theoretically, a simple rubber band device can also be created mimic-ing the human voice. This does sound like a fun high school science project the more I think about it.

Once that has been achieved, the physical characteristics of this rubber band can be broken down and than replicated by biochemists to create a biologic equivalent (or biologically inert) rubber band which can than be transplanted into a human with a damaged vocal cord.

Even to just more faithfully replicate a human voice would be a boom for those whose voiceboxes have been completely removed due to cancer (laryngectomy). Current replacement talking devices sound like a robot using state-of-the-art electrolarynx. Watch video below:



Just a thought that I am sure is easier said than done.

Read the full article in the BBC here. Research paper on this topic to be published in near future.

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Can Placebo Be Used to Help People Instead of Drugs?

On my way to work On December 23, 2010, I heard a great story on NPR regarding how placebos can potentially be used to help people... EVEN if they know it's a placebo!

Based on research done at Harvard, they found that a placebo helped patients with irritable bowel syndrome 59% of the time compared to a similar group that received nothing. Of greater significance... the treatment group with placebo KNEW they were getting a placebo.

Given that many medications have similar (and even lower) improvement rates, that's quite amazing.

Why does placebo work?

My own personal belief is that this is truly a case of mind over matter.

The human body is literally a pharmaceutical manufacturing company able to naturally produce all sorts of chemical compounds. Pretty much every drug that you can take in pill form, the human body already produces within to some degree. Drugs in essence augments what the body is already able to naturally produce.

The placebo effect is (in my opinion) when the human mind is able to boost the production of the appropriate drugs the body is already able to naturally produce.

The REAL key to improving the human health condition and avoid all the drugs and their potential for side effects is to somehow figure out how to enable the placebo effect on command.

Read the NPR story here.

Reference:
Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome. PLoS One. 2010

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Google Body Browser (Google Maps of the Human Body)

Google released a new "map" so to speak of the human body. In the same spirit and controls as the venerable Google Earth, Google Body Browser allows a user to zoom in and out as well as pan across the human body. Here is a window capture of a session when I was checking it out.

Currently, this internet-based program only works with Google Chrome which you can download for free here.

Access Body Browser here after you have Google Chrome installed.

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RANDOM: A Human Life-Cycle Video in 90 Seconds

Title says it all... Wish more commercials strike a more human chord like this one did with me. NPR Radiolab did something similar with an "audio" life-cycle of a baby babbling to a young woman talking in about 90 seconds as well, though for the life of me, I can't remember which episode did that.

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