100 Days Remain: Study reveals feasibility of surviving zombie apocalypse

A new study suggests that, in the case of a zombie infection spreading, less than 300 people would be left alive in the world after just 100 days.

The study, from physics students at the University of Leicester, suggested human survivors would be outnumbered a million to one by the undead in just over three months.

The students, from the University of Leicester Department of Physics and Astronomy, worked from the assumption that a zombie could find one person each day and would have a 90% chance of infecting its victim with the virus. Based off this assumption, they found that just 273 humans would remain after the 100 day period.

In order to reach these numbers, the team made use of the SIR mode; an epidemiological model that describes the spread of a disease throughout a population.

The model splits the population into three categories – those susceptible to the infection, those that are infected and those that have either died or recovered. The SIR model then considers the rates at which infections spread and die off as individuals in the population come into contact with each other.

Included in the student’s formula was a consideration of the lifecycle of a zombie, looking at the susceptible population, the zombie population and the dead population. Furthermore, the time frame in which individuals within the population come into contact was examined.

Ignored, however, were natural birth and death rates as they were considered negligible compared to the virus’ impact over such a relatively short time frame.

If populations were equally distributed, and humanity was unable to effectively fight back, calculations showed that humans would be entirely wiped out in less than a year. However, a follow-up study introduced new parameters, such as the rate in which zombies might be killed and people may have children during the epidemic.

According to this more optimistic set of calculations, human survivability became much more feasible. With the notion that survivors may become less likely to be infected over time due to experience fighting zombies also factored in, it was found that humans would not only survive the epidemic but eventually be able to wipe out the zombies and slowly begin the recovery of the population.

The students’ findings were presented as a series of short articles for the Journal of Physics Special Topics, a peer-reviewed student journal run by the University’s Department of Physics and Astronomy. The student-run journal is designed to give students practical experience of writing, editing, publishing and reviewing scientific papers.

Course tutor Dr Mervyn Roy, a lecturer in the University of Leicester’s Department of Physics and Astronomy, said: “Every year we ask students to write short papers for the Journal of Physics Special Topics. It lets the students show off their creative side and apply some of physics they know to the weird, the wonderful, or the everyday.”

Doctors circumvent broken neck and help patient to move his hands again with spine implant

A man who broke his neck in a dirt-biking accident five years ago has seen both his hand strength and movement improved thanks to an implanted spinal stimulator.

While other devices have shown promise recently in treating paralysis, the approach taken by doctors at Ronald Reagan UCLA Medical Center is unique because the device is implanted in the spine instead of the brain.

Daniel Lu, M.D., Ph.D. , an associate professor of neurosurgery and director of UCLA’s neuroplasticity and repair laboratory and the neuromotor recovery and rehabilitation center, likened the way the stimulator works to the approach commuters take  to dealing with a busy freeway.

“If there is an accident on the freeway, traffic comes to a standstill, but there are any number of side streets you can use to detour the accident and get where you are going,” he said. “It’s the same with the spinal cord.”

To recover feeling in the patient’s hand, the doctors positioned the 32-electrode stimulator below the site of Gomez’s spinal-cord injury, near the C-5 vertebrae in the middle of his neck.

As well as the stimulator, doctors also implanted a small battery pack and processing unit under the skin of the patient’s lower back.

These were small enough to fit in the palm a hand and could be controlled remotely, so doctors were able to regulate the frequency and intensity of the stimulation.

“We can dial up or dial down different parameters and program in the stimulator certain algorithms to activate specific electrodes,” said Lu. “It is an ongoing process that retrains the spinal cord and, over time, allows patients to strengthen their grip and regain mobility in their hands.”

Images courtesy of Ronald Reagan UCLA Medical Center

Improvements to the patient’s hand strength are especially noteworthy given the five years that had passed between the injury and simulator being implanted.

People who suffer spinal-cord injuries usually have a window of only a few months to get the rehabilitation they need in order to maintain at least partial use of their hands. Meaningful improvement is rare more than a year after injury.

“Even though he was injured in 2011, in many ways Brian is a perfect candidate for this experimental treatment. He still has head-to-toe sensation, so he can give us feedback as we fine-tune the stimulator. And he is such a positive and motivated young man,” said Lu.