They then collected a hundred and twenty-seven days' worth of Carpenter's past cell-phone locations, revealing where and, by implication, with whom Carpenter had been at every moment of those four months.
In the past, cell phone cameras have had trouble taking a clear picture of a barcode.
They might constitute present or past cell genes that have evolved beyond recognition.
Most previous studies asked patients already diagnosed with a disease, such as brain cancer, to recall past cell phone use a less reliable method.
In this formulation, the prediction problem can be restated as follows: given your past cell sequence up to time t, which cell will you visit at time (t+Delta t)?
Police helped establish that Carpenter was near the scene of the robberies by securing from his cellphone carrier his past "cell site location information," which tracks which cellphone towers relay calls.
For the calculations above, listed more formally in Appendix S1 in Supplemental Information, we need to estimate probability distributions over the past cell histories being tested and the responses of the cells to each history.
To this end we formulated a conceptual information-theory based framework for measuring microbial memory, thereby introducing tools that begin to observe and quantify the relationship between past cell history and future cell behavior from a new angle.
Like in the transient memory case, past growth medium is remembered better than past cell density, but unlike in the transient memory case, there is no perfectly clean dividing line separating out the long-term responses to the two growth media histories.
The probability that a cell contains prions at time t is then given as follows: <img src="http://journals.plos.org/plosone/article/asset?id=info?doi/10.1371/journal.pone.0004670.e001.PNG" class= inline-graphic"/> In order to evaluate p+(t) we consider every cell as having a history in which out of g past cell divisions (or generations), d were as daughter cells and (g−d) were as mother cells.
