September 26, 2012
Common Mapping Software May Help Forensic Scientists Solve Crimes
redOrbit Staff & Wire Reports - Your Universe Online
Researchers at the Ohio State University have used a common, commercially available type of mapping software to determine whether patterns of change inside the bones of human remains could reveal how the bones were used during life.
“Our bones adapt to the load that´s placed on them. Patterns of tension and compression show up in our internal bone structure, and this software lets us look at those patterns in a new way,” said lead researcher David Rose, a Captain in the Ohio State University Police Division and doctoral student in anthropology.
Although the software has been used in the past to help map the location of objects uncovered at an excavation site -- and Rose has even used the same program to map line-of-site views to develop security plans for campus events -- the current study is the first time anyone has used GIS software to map bone microstructure.
Co-author Sam Stout, professor of anthropology at Ohio State and Rose´s advisor, explained why the study of internal bone structure is important.
“Dave's work allows us to visualize, analyze, and compare the distribution of microscopic features that reflect the development and maintenance of bones, which we can relate to skeletal health and disease — for example, bone fragility in osteoporosis,” he said.
Other applications exist in forensics, Rose said, due to one gruesome fact: when unidentified human remains are discovered, the foot bones are often intact, having been protected by the deceased person´s shoes.
Any information about the person, such as age, sex, or body size, could ultimately help law enforcement in identifying a body.
In the current study, the researchers studied the cross-section of a metatarsal — a long bone in the foot — from a deceased woman who had donated her body to the Division of Anatomy´s Body Donation Program.
Using the bone cross-section, Rose and colleagues demonstrated how the GIS software could be used to show the loads experienced in the foot during gait.
The researchers recorded an extremely high-resolution image of the bone cross-section under a microscope, and used the software to map the location of structures known as osteons.
Osteons are microscopic structures created throughout life to repair small cracks in bones, or to maintain mineral levels in our blood.
The size and shape of the osteons, and the direction of the collagen fibers from which they are made inside bone, are influenced by the loads placed on bones during life.
In this case, the donor´s metatarsal bone showed the predicted pattern of normal bone remodeling, with concentrations of particular types of osteons along the top and bottom of the bone. These osteons could have been formed, for example, by forces the donor experienced while walking. In fact, they were precisely where researchers would expect to see telltale signs of foot flexure and compression.
Rose cautioned that the study serves only as a proof of concept, and that many more bones would need to be studied before GIS software could provide meaningful insight into bone biology.
“Really, we´re just combining very basic principles in GIS and skeletal biology,” he said.
“But I believe that there is a tremendous opportunity for advancements at the intersection of both disciplines. The real advantage to this method is that it offers a new scale for the study of human variation offering to shed light on how we adapt to our surroundings.”
Image 2 (below): This polarized microscope image shows a cross-section of a metatarsal, or long foot bone. White spots on the periphery of the bone are osteons -- structures that fix small cracks in bone and maintain mineral levels in our blood. Image by David Rose.