Saturday, April 28, 2012


I figure that it's about time I get my feet wet with Geographic Information Systems (GIS). The eventual goal is to render original choropleth maps and compile epidemiological data in a graphic and useful way. Below are a couple of very rudimentary maps I authored with ArcGIS Online. The public feature layer sets seem pretty limited, so I'll probably just start making my own once I learn the software and acquire some relevant samples. I'm also playing around with Quantum GIS, GeoDa, and R. Details to follow. 

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Map 1: Greater Cleveland Area, USA Crime Index

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Map 2: Greater Cleveland Area, Populations of Individuals Aged 25+ who Lack College Degree

Saturday, April 14, 2012


The Council of State and Territorial Epidemiologists website has posted a prototype educational module, developed with funding by the CDC, called "EpiVenture: Outbreak Investigation." This software lesson is very similar to proprietary training modules we use in the pharmacy, and it is a very effective tool. The course comprises a mixture of text outlines and terms, with multiple-choice tests and interactive case studies interspersed throughout. I found the prototype version of EpiVenture to be both informative and engaging. Hopefully the CDC/CSTE continue to develop and release new lesson modules for EpiVenture.

Try this self-instructional web course out for yourself:


Wednesday, April 4, 2012


One of the most widely used methods of forensic age estimation via dentition was derived in 1973 by Demirjian, Goldstein, and Tanner.[1] Commonly referred to as "Demirjian's Technique," the changes from initial calcium deposition to complete apex are divided into eight observable stages. Each stage is further characterized by up to three additional qualifying criteria (a,b,c). If only criterion (a) is listed, then it must be met. If (a) and (b) are listed, then at least (a) must be satisfied. If (a), (b), and (c) are listed, then both (a) and (b) must be met. Additionally, "at each stage . . . the criteria for the previous stage must be satisfied" [ibid]. The technique is applied to 7 observed teeth, with the individual "score" from each tooth being added. The resulting sum is then referenced on a corresponding conversion chart with ages ranging from 3 to 17 years, in increments of one-tenth. 

Though the Demirjian method worked well with the original French Canadian subject sample, more recent studies have questioned its effectiveness when applied to sample groups of varied descent. A 2007 study by Tunc and Koyuturk revealed that the technique was less accurate with regard to sampled Turkish children, who   displayed more advanced dental maturity.[2] 
A 2001 article using Belgian children as the sample group confirmed popular findings that the Demirjian method has a tendency to result in over-estimation of age, but employed new adaptations to the scoring system to achieve an increase in accuracy.[3] 

The Demirjian technique remains a well-regarded forensic tool for determining age in sub-adults. As with all estimation methods, there is a discernible margin of error, but overall the technique still provides advantages over other dentition methods, especially those based on tooth eruption, which can be highly influenced by health and environmental factors. It should be remembered that in practical application, a synthesis of various age-estimation methods generally yields the best overall results.    


1. Demirjian, A., et al. A New System of Dental Age Assessment. Human Biology 45(2): 211. 1973.

2. Tunc, E.S.; Koyuturk, A.E. Dental age assessment using Demirjian's method on northern Turkish
    children. Forensic Science International. 175(1): 23-26. 2008.

3. Willems G., et al. Dental Age Estimation in Belgian Children: Demirjian’s Technique Revisited.
  Journal of Forensic Science 46(4): 893-895. 2001. 

Sunday, April 1, 2012


Haiti, with all of its misfortune -- the atrocious sanitary conditions, profound socioeconomic disparity, and recent natural disasters -- serves as an ideal case study for epidemiologists. The U.N.'s ongoing role there provides an example of how organizational interaction can severely affect the health of a population, for better or worse.   

Global Failures on a Haitian Epidemic

Infectious Diseases of Haiti (E-Book)