June 26, 2008

Mystat

I'm always too cheap to pay for a glossy, GUI, point-and-click statistical program, and I waffle between SPSS and Systat. Generally, I prefer Systat because it's easier to use, and the bells and whistles don't drag it down like they do SPSS. Plus, it produces prettier dendrograms than SPSS's icicle and monochromatic ones. Today I needed to generate a simple cluster analysis and dendrogram and downloaded the trial versions of both SPSS 16.0 and Systat 12.0. Annoyingly enough, neither of them worked, probably because I had downloaded the trial versions in the past and they expired. But I discovered that Systat puts out a free version of their program for students. It's called Mystat and, although it sounds like a feminine hygiene product, it actually works pretty well for my purposes: relatively simple statistics. I mean, if I want to do really complicated shit, I'd probably suck it up and learn R. (Kidding. R is impossible for social scientists to understand.) The download took a while, but Mystat quickly installed and I had made this lovely, color-coded dendrogram in under 2 minutes. It tells you that Native Americans on the North Carolina coastal plain in the Late Woodland period have some geographical differences in the expression of genetic traits. Nevertheless, they all still interbred (based on a different statistic). No matter how hard I try, I keep getting sucked back into sidelining in population interaction in ancient NC.

Good Day

I showed up at school yesterday and found three new books waiting for me: Biological Anthropology of the Human Skeleton (2008 edition, hot off the presses!) and two Cambridge titles: Zooarchaeology and Teeth. After reading my packet of teaching evaluations from Cortland and chatting up a colleague I hadn't seen in a while, I headed into a 90-minute meeting with my advisor. I laid out my new plan for isotope analysis (test all first molars for Sr, reserve $2k for further tests on any immigrants I find, and send 50 individuals to a colleague at USF for C/N so as not to waste time learning how to do it myself), and he fully agreed with me. After picking up a lovely smoothie, I settled in to write some email and got a message from a bioarchaeologist who might want me to collaborate on her project with my Roman skeletons - more on this as (if?) it develops. Then I headed over to the isotope geochemistry lab and harassed the lab tech about strontium. There are many steps to this procedure: first, I have to section all 112 teeth into thirds. Then, I need to learn how to use the micromill to drill out 5-20 μg of enamel from near the DEJ. And then the lab tech will teach me how to prepare the enamel and run it through the mass spec. Everyone's schedules are kind of hectic for the summer, though, so I might only get about 5-10 Sr results by August. This should, however, be enough information to bullshit (ahem, I mean, extrapolate) an abstract to the AAPAs. So yay, everything's going as planned, if a bit slowly.

To reward myself for a good day, I bought these:

June 25, 2008

ANT 229

I got my teaching evaluations in the mail today. Usually, even when teaching small classes of 15 students, I have one or two disgruntled students who just loathe me and give me terrible evals. Oddly enough, I got NO bad evals from Cortland. They're all amazingly complimentary. Maybe the kids who hated me weren't in class when I handed out the evals, I don't know. Here are some of the themes that came through...

1. List some of the most interesting/valuable things you have learned from this course.
  • How to find the age and sex of remains, identify someone.
  • Mapping
  • Everything!
2. What did you like best about the way this course was taught?
  • Powerpoint slides
  • She used many different methods to teach.
  • Labs, hands-on activities
3. What changes, if any, should the instructor make in the course in future semesters?
  • None! (seriously - I got nothing other than "none")
4. Think about the qualities you look for in an effective teacher. In what ways does the instructor exhibit these qualities?
  • She communicates well and is prepared for class.
  • She was always available and approachable.
  • Helpful and respectful.
  • She is very interested and enthusiastic about the subject and it shows when she teaches. She was just always excited about forensic anthropology.
  • She was smart!
  • Sense of humor
  • (and, of course, my favorite...) Good looking.

Aw. While I'm excited that the students liked my class, I feel kind of bad for them. What does it say about other courses at Cortland that two of my good qualities are "prepared for class" and "respectful"? Does that imply that other professors aren't those things, and that they aren't enthusiastic about their subject matter?

I am surprised that they liked the mapping activity. Maybe because it was fresh in their minds and because we got to go outside for it. But I'm glad to see that they really did enjoy the labs that I worked pretty hard each week on (and dealt with umpteen logistical issues to accomplish) and am pleased that they enjoyed learning about the human skeleton.

I'm gonna go dissolve into a puddle of happy now.

June 23, 2008

Homer (not Simpson)

News sources have picked up this story in which two classical scholars have "pulled an Ussher" and set the precise chronology of Odysseus' homecoming at... April 16, 1178 B.C. This is why anthropology granting organizations don't fund me. They assume I'm doing inane pseudo-research, that I'm convinced hermeneutics are the key to understanding Dark Age Greece.

Slicing and Dicing

This morning, I drove to RTP to meet with a dentist who is doing research into some specific protein in teeth that perhaps mixes with calcium and... yeah, honestly, his interests were far too complicated for me to really understand. There was a lot of technical, elemental explanation going on. He has been collaborating, however, with the geochemist at UNC in trying to figure out if dentine from different areas of a tooth provide different strontium signatures. If they do, it is theoretically possible to track one person's movement throughout his or her adolescence - on a scale of months rather than years or decades. So he seemed interested in my project and was actually impressed by my box full of 2,000-year-old teeth. (No one else ever is.)

The process of sawing them into thirds was actually fairly simple. He "glued" the tooth to an acrylic pad using simple heated wax. The pad with attached tooth was then positioned above the saw blade, which spun through water to help lubricate its path through the tooth, and then sliced it in two. He moved the saw blade about 3 mm and made a second cut. The tooth, still attached to the wax, was cut into three pieces. The idea, I guess, is to extract both the enamel and the dentine from an area as close as possible to the dento-enamel junction - about 100 microns from this junction in either direction. The closer the enamel is to the DEJ, the earlier in a person's life it was formed. So the idea is to take a sample of enamel very close to the DEJ while not getting any dentine contamination. This is the middle section of a lower left first molar that he sectioned for me. There isn't a lot of enamel left, as you can see indicated by the red line. This individual (from Castellaccio, which had more dental wear than Casal Bertone) had worn his teeth down, even though he was under 20 years old. But there's a lot of dentine to choose from, which is good.

As I noted a few days ago, I was worried that needing enamel from near the DEJ would eliminate some of the children from my study. While it does eliminate very young children (infants whose cusps are just forming), we sectioned the first molar of a child who was around 3-4 years old when he or she died, and there was plenty of dentine. So teeth that I extracted from the crypt (our word for a tooth socket in an archaeological sample devoid of flesh) will likely produce some very good samples of both enamel and dentine. Yay! This is the tooth that the dentist sectioned for me - note the abundance of enamel and clearly demarcated dentine. There's also some sort of organic matter (possibly root material, or possibly mummified/petrified tissue), which is the brown lump in the lower right.

I'm all set up to saw teeth into thirds now, but I'll need to go to the geochem lab tomorrow or Wednesday to learn how to use the drill that will extract the enamel and dentine. And then learn how to prepare those samples for SEM. Yeesh.

The weirdest thing was when the dentist asked me if I wanted to take any precautions against disease when cutting the teeth. I asked what he meant by that, and he said that diseases like hepatitis can survive for a long time in organic material like dentine - and he doesn't want me getting hep-B from ancient Romans. It would be pretty hilarious to explain to Student Health that I got a communicable disease from Oldeus Diseaseus, but I honestly don't think I'm at any kind of risk for catching anything. If I survived plowing through the Casal Bertone skeletons that were covered in rat droppings and cat urine, I doubt that teeth will hurt me. Will they?

Mozilla

Apparently my old blog template doesn't work in Mozilla 3. I confirmed this myself by finally downloading it. It's odd, since the blog template is one of Google's - just modified a bit. So until I can learn enough about their fancy HTML to fix the old template, I'm going minimalist for a while.

June 20, 2008

Tooth Beads

On Monday, I met with a geochemist at UNC to find out how to turn my ancient Roman teeth into information about whence people migrated to Rome. Because there is no geological map of Italy that details the levels of strontium in the bedrock, my research plan included testing first molars (the enamel of which forms by the age of about 4 and doesn't change through life) and midshaft femur samples (as the cortical bone renews itself constantly, giving a picture of the last 5-10 years of a person's life). Testing samples from an individual at a young age and right before death would therefore tell me if s/he moved during his or her lifetime, if the two signatures were different. I took hundreds of teeth from my two sites, and I spent a few days sawing femora in half to get samples of cortical bone from the middle. Turns out, much of my sawing effort was likely pointless - at least in terms of this dissertation research.

The geochemist informed me that bones - particularly those that have been in the ground for thousands of years - are heavily affected by diagenesis, meaning the sample is compromised by the elements around it. In this case, my Roman bones should all give me the same strontium signature - that of the soil they've been buried in for two millennia. It would therefore be unlikely to find someone who had immigrated in the last few years of his life because all the bones will show up as "Roman." As I mulled over the implications for my research, the geochemist told me not to worry - I could use enamel and dentine from teeth instead of enamel and cortical bone. Dentine, unlike enamel, constantly changes throughout life and could give me a strontium signature for the last few years of an individual's life. Great, I figured. Now all I have to do is grind some dentine and some enamel from each tooth, and I'm set for strontium.

However, the second thing that I learned in this meeting was that a dentist at UNC has been doing research into the consistency of tooth enamel. He found that, at the elemental level, it seems that the constituent parts of enamel dissolve and reform throughout an individual's life. So although all textbooks say that enamel forms once and never changes, his latest research says that's not necessarily true - some amount of enamel does change, particularly the occlusal surface, which is exposed to the outside world and comes into contact with all sorts of things in both masticatory and extramasticatory functions. Uh oh, I said. Fortunately, this dentist thinks that the enamel that's not exposed - namely, the part at the junction between the enamel and the dentine - does not change significantly through a person's life. So it is possible to drill out this specific layer of enamel and compare it to the dentine to analyze the strontium signatures from two different eras in a person's life. Phew.

This does mean that I might not be able to test children whose first molars were still forming. Teeth form from the cusps down rather than the roots up, so I have several molar crowns from children and even some individual cusps from babies. I don't think these will be useful now, although I'll ask the dentist on Monday. We're meeting up so that he can teach me how to drill the special enamel from a tooth. I'm not sure how many articles have been published that use this new method of enamel extraction - perhaps none. It's exciting to be using cutting-edge (pun intended) research in this project, but it means it'll likely take a bit longer than I thought to run all these samples.

Since I needed the teeth organized - they were all in bags in a giant tupperware that I didn't really look at since I left Rome - I enlisted Trey's help to rebag the teeth and organize them. Tiny bags can be found on short notice at any craft store ($1.50 for 100), and bead boxes are perfect for organizing the bags of teeth into numerical order. As I was buying the bead bags and containers at Jo-Ann Fabrics the other day, the cashier looked at me and said, "Oh, planning to start a big beading project?" I smiled and said, "Oh, yes." It reminded me of a day last summer at the lab in Rome, when I had laid out all the loose teeth from one individual in order. Orso came in, smiled, and said, "Fai un bracciale?" Yes, I can now make an entire bracelet of teeth.

June 10, 2008

Casal Malnome

Jeff sent me a link to this AP story about a lower-class necropolis uncovered last year in Rome after a bunch of tombaroli (grave robbers) were found searching it for goods. What the archaeologists found was a cemetery with somewhere between 250-320 graves (it depends on the report you read), most of whom were male and most of whom suffered from a variety of pathologies that are interpreted as being evidence of "transport and carrying of heavy loads, in an especially humid environment..." I'm not sure how they can tell the climate from spinal pathology, but I don't doubt there was spinal pathology. I would question just how much they found, though, in light of a presentation I saw at the AIAs where an Italian researcher classified normal vertebrae as having massive herniations. It is possible, however, that this was a cemetery for slaves or manual laborers, which would explain the disproportionate number of males and the excessive pathologies that lead one of the Italian articles to describe the men as "camels."

Unlike the AP story, the Italian one in La Repubblica has 9 photographs and a video of archaeologists recovering a skeleton. The video is hilarious, with really bizarre music, so I encourage you to click here even if you don't know Italian (I can't seem to steal and embed it). Here are some of the photos I took from La Repubblica, with translated captions.

1. The site of Casal Malnome, on the outskirts of Rome near the airport. It dates to the 1st-2nd century AD, around the same time as both of my sites, and was likely the burial place of lower class individuals.



2. Tomb 115, a cappuccina-style burial complete with ceramic tubing to the surface, where loved ones could pour liquid offerings of olive oil or wine.



3. One of the skeletons, with a small pottery vessel at his/her feet.



4. An interesting necklace made of amber, seashells, and teeth, found in a child's tomb.



5. An oil lamp decorated with a scene of grapes.



6. An "obol of Charon" - a coin placed in the dead person's mouth to pay the ferryman to cross into the underworld. Some of my skeletons also had coins in their mouths.



7. Saving the best for last... according to the head of the anthropology service of the archaeological superintendency of Rome (the woman I worked with), this man's jaw was fused to his skull. Additionally, she thinks that he had dental work done so that he could be fed through his teeth, probably with thin gruels or other liquids, as he could not chew. (The caption at La Repubblica says that he was born with a closed mouth and could not breathe, but I find both of those to be unlikely.)



June 1, 2008

Chillin' on the Hill

After at least 10 solid days of packing followed by 4 days of moving and unloading, we're back in North Carolina. The logistics of the move all worked out, but I still have the bruises from dropping random pieces of furniture on my limbs. Mostly, we've been taking this week as a vacation, before Patrick starts his new job at BlueStripe and I do whatever it is I am going to do this summer. We're housesitting for the summer for an anthropology professor who's on my committee. Do you want to come visit us?

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