Chronoprints: Identifying Samples by Visualizing How They Change over Space and Time.

The modern tools of chemistry excel at identifying a sample, but the cost, size, complexity, and power consumption of these instruments often preclude their use in resource-limited settings. In this work, we demonstrate a simple and low-cost method for identifying a sample based on visualizing how the sample changes over space and time in response to a perturbation. Different types of perturbations could be used, and in this proof-of-concept we use a dynamic temperature gradient that rapidly cools different parts of the sample at different rates. We accomplish this by first loading several samples into long parallel channels on a "microfluidic thermometer chip." We then immerse one end of the chip in liquid nitrogen to create a dynamic temperature gradient along the channels, and we use an inexpensive USB microscope to record a video of how the samples respond to the changing temperature gradient. The video is then converted into several bitmap images (one per sample) that capture each sample's response to the perturbation in both space (the y-axis; the distance along the dynamic temperature gradient) and time (the x-axis); we call these images "chronological fingerprints" or "chronoprints" of each sample. If two samples' chronoprints are similar, this suggests that the samples are the same chemical substance or mixture, but if two samples' chronoprints are significantly different, this proves that the samples are chemically different. Since chronoprints are just bitmap images, they can be compared using a variety of techniques from computer science, and in this work we use three different image comparison algorithms to quantify chronoprint similarity. As a demonstration of the versatility of chronoprints, we use them in three different applications: distinguishing authentic olive oil from adulterated oil (an example of the over $10 billion global problem of food fraud), identifying adulterated or counterfeit medication (which represents around 10% of all medication in low- and middle-income countries), and distinguishing the occasionally confused pharmaceutical ingredients glycerol and diethylene glycol (whose accidental or intentional substitution has led to hundreds of deaths). The simplicity and versatility of chronoprints should make them valuable analytical tools in a variety of different fields

New strategies for human papillomavirus-based cervical screening.

Author manuscript; published in final edited form as: Womens Health (Lond Engl). 2013 September; 9(5):. doi:10.2217/whe.13.48Human papillomavirus testing has been shown to be far more sensitive and robust in detecting cervical intraepithelial neoplasia 2 and above (and cervical intraepithelial neoplasia 3 and above) for cervical screening than approaches based on either cytology or visual inspection; however, there are a number of issues that need to be overcome if it is to substantially reduce the morbidity and mortality associated with cervical cancer at the population level. The two main issues are coverage (increasing the number of women who participate in screening) and the management of women who test positive for high-risk human papillomavirus. This article will review the potential for vaginal self-collection to improve coverage and the options for triage of high-risk human papillomavirus-positive women in high-resource and low-resource settings

Earth & Mars: As Different as They are Alike

This poster shows a visual comparison of Mars and Earth. The back contains panels that go into detail on Mars science and explorations. It contains eleven lessons and resources for teachers. Educational levels: Primary elementary, Intermediate elementary, Middle school, High school

The Benefits Planner: SSI’s Income and Resource Rules Revised - Working With The Revised Rules To Ensure Eligibility For SSI And Medicaid

This newsletter will provide valuable information on how work for persons with disabilities effects government benefits, with an emphasis on the Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) work incentives. Each newsletter will contribute to an ongoing dialogue on topics related to benefits and work

Diverse, remote and innovative - Prospects for a globally unique electricity network and market in Western Australia

WA’s electricity industry supply infrastructure comprises the South West Inter-connected System (SWIS), the North West Interconnected System (NWIS) and 29 regional non-interconnected power systems 1. WA exhibits a diversity of generation systems located in some of the most isolated regions of Australia, supplying a wide range of energy demand profiles. These characteristics and the unique networks that comprises WA’s electricity infrastructure makes WA a unique place to research, develop and integrate new technical options within a world-class industrialised electricity system