Update: Model Selection and Fieldwork in Maine

The summer session is almost at an end, and the past few weeks have been absolutely packed! I have fully incorporated the milkweed data that we took in the field last month into a new set of models. We now have 4.5 years of data tracking thousands of individual milkweed stems from sprouting/germination until reproduction and dieback at the end of the season each year. This is enough data to make robust statistical models for the vital rates of the population (survival, growth, reproduction), which is what I have been working on. The process of deciding which type of model is the best fit and most suitable for our purposes is a challenging one that takes a surprising amount of time and thought. This stage in the modeling process is often referred to as “model selection” (and validation), and is very heavy on the statistics. Various techniques are used to quantify and visualize how and where a model is performing well and where it may be lacking. A huge part of this involves keeping track of which models can actually be compared with one another in any sort of a meaningful way. This was one of the issue I needed to solve in my analysis. Specifically, we are working with a class of models called Generalized Linear Mixed Models (GLMMs), which do not perform the same way in tests designed for standard linear models. In order to get a more accurate way of assessing the quality of our models, I needed to find and implement some new statistical tools that would make these types of models comparable for us. The below plot is an example of what I used to visually assess the new models, and was generated by the DHARMa package in R. If it looks even remotely interesting to you, check out it’s vignette here.DHARMa Residual Plot

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Comparing Viral Communities Using RAPD-PCR and Gel Electrophoresis

These past few weeks I have been working on using the viral concentrates I made for RAPD-PCR and gel electrophoresis. To make a viral concentrate, I filter off the bacteria and centrifuge the water samples at 38,000 rpm to force the viruses to the bottom of the centrifuge tubes. I then re-suspend the viruses in a much smaller volume. I have 27 viral concentrates to make gels for, plus the water samples I will continue to collect until October.

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Off the 405

As intern in the events department, I am helping out each member of the team when their events are on. The Getty hosts an impressive number of events and this team of ten are always super busy. The nice thing is that there are no private events and because of neighbours and noise issues, the number of evening events the center can have is restricted. In spite of this, things can still get pretty crazy with multiple events on at the same time.

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It’s hard to search for sources about a government without freedom of press…

Hello again from Buenos Aires, Argentina! I’ve been down here hiding in the hemeroteca, or newspaper archives, searching for primary sources that I can incorporate into qualitative analysis of the activism of the Madres de Plaza de Mayo. I decided to start by looking at La Prensa and La Nación, two of the most widely read and most respected news sources in Argentina. Both have been around for a long time and are known for being reliable sources— comparable to the New York Times or Washington Post. However, I was having a lot of trouble finding any articles or editorials that mentioned the Madres, even around the days when I know marches or incidents occurred from reading biographies about the Madres. I quickly realized that the issue here wasn’t my Spanish reading skills, but rather that the most powerful and widely read newspapers in Argentina during the time of the dictatorship were under the thumb of the army and would not publish news about any resistance.

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Learning the Ropes of Pb Digestions

Coming into this summer I didn’t know exactly what to expect. I knew what I would be doing based on reading numerous papers and theses, but I admit I couldn’t fully visualize the step by step process I would be going through. After getting situated in Williamsburg, I headed to the lab in McGlothlin St. Hall to meet with my advisor Jim Kaste. Over the next couple weeks I got situated and comfortable with the equipment and procedures. I learned early on that the research I was conducting required fine motor skills and a lot of patience.

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