Caught by a hair: Quick, new identification of hair may help crime fighters

Lily Huang crushes up the human hair prior to testing. Credit: Image courtesy of Queen's University

Crime fighters could have a new tool at their disposal following promising research by Queen's professor Diane Beauchemin.

Dr. Beauchemin (Chemistry) and student Lily Huang (MSc'15) have developed a cutting-edge technique to identify human hair. Their test is quicker than DNA analysis techniques currently used by law enforcement. Early sample testing at Queen's produced a 100 per cent success rate.

"My first paper and foray into forensic chemistry was developing a method of identifying paint that could help solve hit and run cases," explains Dr. Beauchemin. "Last year, Lily wanted to research hair analysis, so I started working in that area."

Blood samples are often used to identify gender and ethnicity, but blood can deteriorate quickly and can easily be contaminated. Hair, on the other hand, is very stable. Elements in hair originate from sweat secretions that alter with diet, ethnicity, gender, the environment and working conditions.

Dr. Beauchemin's process takes 85 seconds to complete and involves grinding up the hair, burning it and then analyzing the vapour that is produced.

"Our analysis process is very robust and can be used universally," says Ms. Huang. "One of our samples even included dyed hair and the test was 100 per cent accurate. The test was able to distinguish East Asians, Caucasians and South Asians."

Dr. Beauchemin says she has contacted law enforcement agencies about using the new technology. She is also planning to collect more hair samples and continue her research with a goal of pinpointing where exactly in the world the hair sample is from, to look for more ethnicities and determine specific age.

Source: Queen's University

Study reveals how dogs detect explosives, offers new training recommendations

A new study found dogs react best to the actual explosive, calling into question the use of products designed to mimic the odor of C-4 for training purposes. Credit: Image courtesy of Indiana University-Purdue University Indianapolis School of Science

A research team at Indiana University-Purdue University Indianapolis (IUPUI) has helped determine the science behind how canines locate explosives such as Composition C-4 (a plastic explosive used by the U.S. military). The study found the dogs react best to the actual explosive, calling into question the use of products designed to mimic the odor of C-4 for training purposes. These findings are the culmination of a four-year contract funded by the U.S. Department of Defense (DOD).

"Appropriately, dogs that are trained to find real explosives are going to find real explosives and not much else," said John Goodpaster, Ph.D., associate professor of chemistry and chemical biology and director for the Forensic and Investigative Sciences Program in the School of Science at IUPUI.

The effectiveness of trained detector dogs is well established, but the study sought to determine which chemical compounds cause a dog to recognize a particular explosive and alert to it. Previous studies have suggested that certain non-explosive chemicals emitted by Composition C-4 cause dogs to alert, and that these specific chemicals could be used as mimic substances to train the dogs in place of real explosives.

In the first phase of the study, IUPUI researchers discovered that the non-explosive chemicals given off by C-4 mimics also are present in a variety of everyday plastic objects. Objects tested included PVC pipes, electrical tape, movie tickets, a plastic grocery bag and plastic food wrapping. Several of the tested items emitted appreciable levels of a mimic compound recommended by some vendors for training canines.

The second phase exposed 33 trained canines from the DOD, Department of Justice, Amtrak and other agencies to these vapors to see if the dogs would respond. The field trials demonstrated that the dogs failed to respond in any significant way to specific odor compounds found in C-4. The results indicate that if the dogs are trained on the full scent, they will only detect real explosives.

"The canines are not easily fooled -- you can't pick and choose components of explosive odors and expect the dog to respond," Goodpaster said. "Dogs are specific and it's the full scent that causes them to alert."

The study also sought to better establish the scientific facts needed for canine detection to be legally admissible evidence -- an effort that found using mimic compounds could present challenges in court. By training with real explosives, false positives are unlikely in the field. Overall, the team recommended that dogs be trained with actual, not mimic, explosives.

While there is technology available to search for explosives, canines remain the best option because of their speed, sensitivity and ability to search large numbers of items, Goodpaster said. Co-authors on the study include current and former IUPUI School of Science undergraduate and graduate students: William Kranz, Kelley Kitts, Nicholas Strange, Joshua Cummins and Erica Lotspeich.

The full study appears in the March 2014 Forensic Science International.

Source: University-Purdue University Indianapolis School of Science

Smelly discovery challenges effectiveness of antimicrobial textiles

University of Alberta textiles scientist Rachel McQueen has found that anti-odor clothing may not be living up to its promise. Credit: University of Alberta

Anti-odour clothing may not be living up to its promise, and an ALES researcher is saying it could all be a matter of how the product was tested.

In two separate experiments, Human Ecology researcher Rachel McQueen and her team found that some antimicrobial textiles were far more effective at performing their advertised tasks in the lab than in testing on humans. In one experiment, the fabrics were designed to help lower the risk of infection; in the second, the fabric was treated with a silver compound, which can be marketed preventing odour in clothing.

"We aren't necessarily seeing the same results in the lab about antimicrobial activity translating into antimicrobial activity when we're wearing them next to our bodies in real life," she said.

The first experiment analyzed the effectiveness of three different textiles coated in antimicrobials triclosan, a zinc pyrithione derivative and a silver chloride-titanium dioxide compound. After putting the fabric on people's arms under plastic film for 24 hours, the silver-chloride titanium dioxide compound hardly eliminated any bacteria. Overall, they found the in vivo -- tested on humans -- results were not comparable with in vitro -- tested in the lab -- results in how they prevented microorganisms from surviving in the textile.

The second test had similar results, and tested whether polyester textiles treated with bioactive concentrations of an antimicrobial silver chloride compound reduced armpit odour and bacterial populations. Although lab testing showed antimicrobial activity, the treated fabrics did not lower odour or bacterial intensity in in vivo testing.

McQueen said that anything from sweat to the proteins in the human body can disrupt the antimicrobial properties of a fabric.

"In reality, when it goes to the point that it gets put on a textile... it may not have the same level of effectiveness as the ones they studied," she said.

McQueen said these findings highlight the importance of in vivo testing, which is less common than in vitro testing, in textile product development. But, because the textiles appear to be effective at reducing bacteria in the lab, she said they may be advertised as being anti-odourous, although they may not necessarily be so when actually worn.

So, for now, McQueen suggests thinking twice before trusting textile's advertised claims.

"It's just a real spectrum to how effective they may truly be. So I'd probably say, from a consumer's point of view, if you're actually buying something that says it's antimicrobial, it may not be," she said. "I think that's important to consider in relation to a lot of claims made about textiles, that is, to be skeptical about the claims marketers make."

McQueen's research was recently published in the International Journal of Clothing Science and Technology.

Source: University of Alberta

Up to 80 million bacteria sealed with a kiss

Couple about to kiss (stock image). As many as 80 million bacteria are transferred during a 10 second kiss, according to research published in the open access journal Microbiome.

As many as 80 million bacteria are transferred during a 10 second kiss, according to research published in the open access journal Microbiome. The study also found that partners who kiss each other at least nine times a day share similar communities of oral bacteria.

The ecosystem of more than 100 trillion microorganisms that live in our bodies -- the microbiome -- is essential for the digestion of food, synthesizing nutrients, and preventing disease. It is shaped by genetics, diet, and age, but also the individuals with whom we interact. With the mouth playing host to more than 700 varieties of bacteria, the oral microbiota also appear to be influenced by those closest to us.

Researchers from Micropia and TNO in the Netherlands studied 21 couples, asking them to fill out questionnaires on their kissing behaviour including their average intimate kiss frequency. They then took swab samples to investigate the composition of their oral microbiota on the tongue and in their saliva.

The results showed that when couples intimately kiss at relatively high frequencies their salivary microbiota become similar. On average it was found that at least nine intimate kisses per day led to couples having significantly shared salivary microbiota.

Lead author Remco Kort, from TNO's Microbiology and Systems Biology department and adviser to the Micropia museum of microbes, said: "Intimate kissing involving full tongue contact and saliva exchange appears to be a courtship behavior unique to humans and is common in over 90% of known cultures. Interestingly, the current explanations for the function of intimate kissing in humans include an important role for the microbiota present in the oral cavity, although to our knowledge, the exact effects of intimate kissing on the oral microbiota have never been studied. We wanted to find out the extent to which partners share their oral microbiota, and it turns out, the more a couple kiss, the more similar they are."

In a controlled kissing experiment to quantify the transfer of bacteria, a member of each of the couples had a probiotic drink containing specific varieties of bacteria including Lactobacillus and Bifidobacteria. After an intimate kiss, the researchers found that the quantity of probiotic bacteria in the receiver's saliva rose threefold, and calculated that in total 80 million bacteria would have been transferred during a 10 second kiss.

The study also suggests an important role for other mechanisms that select oral microbiota, resulting from a shared lifestyle, dietary and personal care habits, and this is especially the case for microbiota on the tongue. The researchers found that while tongue microbiota were more similar among partners than unrelated individuals, their similarity did not change with more frequent kissing, in contrast to the findings on the saliva microbiota.

Commenting on the kissing questionnaire results, the researchers say that an interesting but separate finding was that 74% of the men reported higher intimate kiss frequencies than the women of the same couple. This resulted in a reported average of ten kisses per day from the males, twice that of the female reported average of five per day.

To calculate the number of bacteria transferred in a kiss, the authors relied on average transfer values and a number of assumptions related to bacterial transfer, the kiss contact surface, and the value for average saliva volume.

Source: BioMed Central