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Category Archives: Space Program

Drowning In Space: When Your Space Suit Is Your Enemy

Gemini 4 Spacewalk

Gemini 4 Spacewalk

 

You would think that the last thing that an astronaut would fear while performing a spacewalk would be drowning. How on earth does that happen? Oh, wait a minute, he wouldn’t be on Earth. I guess out there in the wild blue yonder all the rules change. Ask Luca Parmitano, an Italian astronaut who worked on board the International Space Station (ISS). It seems that over a liter of water accumulated inside his helmet obstructing his ears and his eyes and raising the possibility that he could drown in space.

He isn’t the only one to suffer spacesuit problems during spacewalks, Extravehicular Activities or EVAs in NASA-speak. Here is an interesting article from The New Scientist on five such situations.

 

 
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Posted by on September 3, 2013 in Asphyxia, Medical Issues, Space Program

 

Surgery in Zero Gravity

How do you do surgery in zero gravity?

Very carefully. And it helps to have NASA’s latest toy.

You’ve probably seen videos of astronauts playing with water in space. No dripping or dropping here. Due to their inherent surface tension and the lack of gravity applying any external force, liquids tend to form into spheres and float around. Fun stuff.

 

But what about blood? Of gall bladder fluid? Or, yuck, pus from an infected wound? These are not materials you want floating around in your space capsule, or your face.

The Aqueous Immersion Surgical System (AISS) just might solve this problem. It is a saline-filled transparent box with airtight ports through which orthoscopic surgical tools can be passed.

 

 

Very clever and very cool.

 
 

Space Travel and Brain Injury

We’ve been to the moon, astronauts have spent months floating around the space station, and the dream of many is to eventually visit Mars. But, space isn’t all that friendly to humans.

 

The Original 7 Mercury Astronauts

 

Besides the obvious dangers associated with take off and re-entry, and living in an enclosed environment miles above the Earth where immediate rescue is problematic, there are several important medical issues related to prolonged microgravity exposure.

 

Apollo 11’s Buzz Aldrin on the Lunar Surface

 

For years we’ve known about the muscle wasting and bone mineral loss that follows the absence of weight bearing in microgravity. Now a new problem has been uncovered: Idiopathic Intracranial Hypertension.

That’s a big word meaning an elevation of the pressure inside the skull. This seems to be due to cerebral edema, an excess accumulation of fluid within the brain that leads to brain swelling. And since the skull, unlike a balloon, is rigid and cannot expand with this increased pressure, the brain suffers.

In a NASA study of 27 astronauts who had spent an average of 108 days in space, MRI brain scans revealed that one third suffered some degree of swelling, typically involving the optic (vision) nerves. In some astronauts, there was also some flattening of the back of the eyeball, which affected focusing, and problems with the pituitary gland, the so-called master gland that regulates many of the body’s hormones.
This will require further study, but on its surface it appears to complicate long-term space travel. Mars just got a little further away.

 

 
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Posted by on July 17, 2012 in Medical Issues, Space Program

 

Q and A: Could the Sensitivity of Modern DNA Testing Prove Confusing in a Contaminated Crime Scene?

Q: I attended your forensics panel at SINC OC and remember you saying that DNA can be extracted from a single cell found at the scene. Is that correct? I have a meticulous serial killer that I want to leave only DNA clues but (for me at least) that begs two questions: How far is the one-cell method of DNA ID developed now and wouldn’t the DNA results become muddied since many persons would have been in the same area? In other words, how would friends/family/acquaintances be ruled out or in as suspects when they most likely would have physical contact with the victim?

P.I. Barrington, Riverside, CA

A: The techniques that allow very small DNA samples to be useful are well-established and have been the last 15 years. They are the polymerase chain reaction (PCR) and short tandem repeats (STR). Together they are referred to as PCR/STR. The PCR technique basically copies the existing DNA chains so that a single DNA chain–therefore a single cell–can be used to produce as much DNA as is needed. Since the copying is exact, all the DNA produced by this method is identical to the original DNA strand. This process is called amplification but it is basically a duplication of the existing strand. The short tandem repeat is simply a method of analyzing the DNA and producing a profile from multiple short segments of the target DNA.

What this all means is that a very small DNA sample, and theoretically only a single cell, can be used to generate a DNA fingerprint.

 

 
Your other questions bring up a very difficult problem that will be an increasing problem in the future. If the DNA techniques are so sensitive, what do we do about extraneous DNA found at the scene? Since people shed skin cells all the time, a busy public place could theoretically house the DNA from thousands of people. But as with the blues, context is everything.

If the crime scene DNA is found in a drop of blood or a smear of semen or a fingerprint, the DNA found in that sample would belong to the person that left the sample behind. Could it be contaminated by other DNA? Of course, but this contaminant would be in very small amounts. In addition, the extraneous DNA might belong to a family member or friend or someone who had a reason to be at the scene before or after the murder. That’s not always true in the case of the killer. Often he has no innocent reason for having deposited his bodily fluids or fingerprints at a murder scene.

So let’s look at a scenario such as this: the killer does his deed. He washes his hands in the sink. He uses a hand towel to dry his hands. The crime lab technicians evaluate the towel and find DNA present. The DNA proves to be from several people. The victim, the victim’s spouse, the victim’s children, and maybe the victims next-door neighbor who visits daily. But another DNA is found. One that cannot be matched to any known individual. Later a suspect is identified and indeed this DNA matches him.

What does this evidence tell investigators? It tells them what any evidence does. That the individual identified by the DNA had contact with that towel. That’s it. It doesn’t say anything else. This is true of all evidence. It merely serves as a link between a person and another person, place, or object. Your investigators must then uncover the circumstances under which this person’s DNA was left on that towel. If he can prove he had been there for dinner the night before and had indeed washed his hands then this evidence is of little value. But if he swears that he doesn’t know the victim and has never been in the victim’s home, that’s an entirely different story. Again, context is everything.

 

 

New Rapid DNA Technology

The recent killing of Osama bin Laden and the very rapid determination of his identity through DNA and other techniques has generated a great deal of discussion on just how fast DNA analyses can be done. The facts are that with good samples a DNA profile and its matching against a known profile can be done in a few hours, perhaps as little as two or three. But there’s new technology on the horizon that might reduce this time to less than an hour and, just as important, allow this testing to be done in the field by non-specially-trained individuals.

Network Biosystems (NetBio) is the creator of this portable instant DNA scanner that utilizes microfluidics, a rapidly expanding technology that makes use of very small volumes of liquids and microcapillary tubes. Since it is portable, rapid, and doesn’t require a scientifically-trained operator, it will no doubt prove to be a valuable forensic tool.

Lab on a Chip (LOCAD)

I first learned about this technology a couple years ago when I spent time with Dr. Lisa Monaco at NASA’s Marshall Space Flight Center in Huntsville, AL. She explained the microfluidic technology she employs in her Lab-on-a-chip (LOCAD) research and indeed one of her devices is currently roaming around Mars, seeking evidence of nitrogen, oxygen, water, and other chemicals, as well as the amino acids required for life.

Dr. Lisa Monaco

Whether on the surface of Mars or at a crime scene, this technology has a bright future and I suspect we will see an increasing number of uses for it.

 
 

The Andromeda Strain Lives

Remember the late Michael Crichton’s landmark science fiction novel and pretty cool movie The Andromeda Strain? The story revolved around an alien strain of biological material that hitchhiked its way to Earth on a retrieved military satellite. Pure science fiction. Great science fiction. Totally speculative.

 


But now it just might have happened. It seems that astrobiologist Dr. Richard B. Hoover from NASA’s Marshall Space Flight Center has uncovered an alien, space-traveling bacterium. This one grabbed a ride on a meteorite. Scanning electron microscopy has revealed the fossil of a large bacterium, similar to one found on Earth, hidden inside the chunk of space rock.

Is this evidence of life in space? Is it conceivable that some space traveling organism could fall to earth and wipe us all out? Who knows. Time will tell.

As it says on the cover of The Hitchhiker’s Guide to the Galaxy: “DON’T PANIC.”

 


Dr. Hoover has invited 100 experts to review and analyze his work so hopefully we will know more about this creature, bacterium, apocalyptic organism, or what ever it is as further study is done.

But it should add speculative fuel to those of you who write in the sci-fi genre.

 

NASA/CSI Event

The past two days have been busy but the opening of the CSI: The Experience exhibit here in Huntsville at the US Space and Rocket Center was great. Did the ribbon cutting on Friday night and then gave a couple of public talks yesterday. So far it looks like the biggest exhibit they’ve ever had. The interest in forensic science continues. If you are in the area don’t miss it. It’s definitely worthwhile.

The exhibit is excellent. Very interactive. Friday afternoon a group of high school seniors from Bob Jones High School were the first to see the exhibit. They went through the various crime scenes very quickly and mostly came to the correct solutions.

Then I visited with Chris Johnson and Scott Saint with GTAC–the Geospatial Training and Application Center. They use Google Earth, Sketch Up, and a government only Virtual Alabama system (high resolution images of the state made by low flying aircraft–much clearer than Google Earth’s space based images) to create 3D crime scenes, neighborhoods, buildings, etc. It us used by law enforcement, fire and rescue organizations, disaster planners, and Homeland Security. Amazing work they are doing. I hope to have them as guest bloggers soon to discuss their fascinating program.

At the Friday night VIP reception I had a chance to chat with solar physicist Dr. David Hathaway who along with Paul Meyer developed the VISAR (Video Image Stabilization and Registration) system that is used to enhance images and videos. You know, read that licenses plate caught by a fuzzy ATM camera. Or clear up a tattoo on the arm of a convenience store robber. Great stuff. A couple of years ago I had the opportunity to visit with him about his work in solar imaging and his development of VISAR. Dr. Hathaway appears as Dr. Wendell Volek in a couple of scenes in my book STRESS FRACTURE.

This has been an exhausting but unbelievable weekend. Here are some pics from the Huntsville Times of my talks and book signings.

 
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Posted by on January 30, 2011 in General Forensics, Space Program

 
 
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