The one-of-a-kind pattern of ridges and valleys in a fingerprint may not only betray who was present at a crime scene. It may also tattle about what outlawed drugs a suspect handled.

With advanced spectroscopy, researchers can detect and measure tiny flecks of cocaine, methamphetamine and heroin — in some cases as little as trillionths of a gram — on a lone fingerprint. The study, led by researchers at the National Institute of Standards and Technology in Gaithersburg, Md., appears May 7 in Analytical Chemistry.
Using an ink-jet–printed array of known quantities of drugs, researchers calibrated their spectroscopy techniques to measure specks of the chemicals. Then, using a 3-D printed plastic finger and a synthetic version of finger oil, researchers created drug-tainted fingerprints pressed onto paper or silicon.

On paper, the researchers detected as little as 1 nanogram of cocaine and amounts above 50 nanograms of methamphetamine and heroin. On silicon, the method picked up as little as 8 picograms of cocaine and heroin and around 1 nanogram of methamphetamine.

Researchers could also point to the location of the drugs on the fingerprint— at the peaks or dips of the pattern, for instance. Such information, the authors say, could help investigators finger what chemicals a suspect handled first and help corroborate a timeline of events in a crime.

In the animal world, just like the human one, sometimes it’s not easy being mom. Fellow blogger Laura Sanders will tell you all about the trials and tribulations of being a mother to Homo sapiens. But some moms of the animal kingdom make sacrifices that go far beyond carrying a baby for nine months or paying for college.

Binge-eating sea otters
Adult female sea otters spend six months out of every year nursing at least one pup, sometimes two. Feeding herself isn’t easy — she’s got to eat the equivalent of 20 to 25 percent of her body mass every day to survive. But that amount has to increase while she’s nursing. By the time a pup is weaned at six months old, mom has to nearly double her food intake, researchers reported last year in the Journal of Experimental Biology. And to make matters worse, sometimes her kid will steal her food.
Single, starving mom
About two months before giving birth, a polar bear will enter her maternity den, remaining there for four to eight months. She stays holed up for that entire time, never eating, never drinking. Her cubs, only about half a kilogram at birth, grow quickly feeding on mom’s rich milk. And once they’re big enough to venture out, mama bear leads her babies straight to the sea so she can finally catch herself a meal.

Walled in by poo
Various species of Asian hornbills all share a similar nesting strategy: To protect her eggs from predators, mom walls herself up in a tree with a combination of mud, feces and regurgitated fruit. She leaves one tiny hole, through which dad feeds her for up to four months when mother and children are finally ready to emerge.

Endless sleepless nights
Human babies are known for their ability to rouse mom with their cries and prevent her from getting much sleep. But orca and dolphin moms don’t sleep at all for a month or more after they give birth. Unlike human babies that need a lot of sleep, tiny orcas and dolphins don’t sleep in the weeks after they’re born. That means no sleep for mom.

It’s mom for dinner
There’s a hint in the name of a limbless amphibian called Microcaecilia dermatophaga — young caecilians eat the skin of their mother, researchers reported in 2013 in PLOS ONE. But in a recent issue of Science News, Susan Milius highlighted an even more disgusting case of mom serving herself up for her kids: A female Stegodyphus lineatus spider feeds her young on a regurgitated slurry made up of the last meals she’ll ever eat — and her own guts. Milius writes:

“As liquid wells out on mom’s face, spiderlings jostle for position, swarming over her head like a face mask of caramel-colored beads. This will be her sole brood of hatchlings, and she regurgitates 41 percent of her body mass to feed her spiderlings.”

The next time your mom talks about how much she sacrificed for you, say thanks, but remember, at least you didn’t eat her stomach.

A zap to the head can stretch the time between intention and action, a new study finds. The results help illuminate how intentions arise in the brain.

The study, published in the May 6 Journal of Neuroscience, “provides fascinating new clues” about the process of internal decision making, says neuroscientist Gabriel Kreiman of Harvard University. These sorts of studies are bringing scientists closer to “probing some of the fundamental questions about who we are and why we do what we do,” he says.
Figuring out how the brain generates a sense of control may also have implications for people who lack those feelings. People with alien hand syndrome, psychogenic movement disorders and schizophrenia can experience a troubling disconnect between intention and action, says study coauthor Biyu Jade He of the National Institutes of Health in Bethesda, Md.

In the study, the researchers manipulated people’s intentions without changing their actions. The researchers told participants to click a mouse whenever the urge struck. Participants estimated when their intention to click first arose by monitoring a dot’s position on a clockface.

Intention to click usually preceded the action by 188 milliseconds on average, the team found. But a session of transcranial direct current stimulation, or tDCS, moved the realization of intention even earlier, stretching time out between awareness of intention and the action. tDCS electrodes delivered a mild electrical zap to participants’ heads, dialing up the activity of carefully targeted nerve cells. After stimulation, intentions arrived about 60 to 70 milliseconds sooner than usual. tDCS seemed to change certain kinds of brain activity that may have influenced the time shift, EEG recordings suggested.

The results highlight how thoughts and intentions can be separated from the action itself, a situation that appears to raise thorny questions about free will. But these tDCS zaps didn’t change the action outcome or participants’ feelings of control, only the reported timing of a person’s conscious intention.