 Thank you very much, Liv. Good afternoon again, everyone. I'm going to be, well, first of all, I'm going to try and not rush, but at the same time I'm going to do my absolute best to stick to time, so bear with me. I'm going to be talking about ways that we can better understand human barrier to follow me by using actualistic experiments with human remains, like the ones that Clara just presented on, in conjunction with different 3D data collection techniques as well as data analysis techniques. Again, as a warning, this presentation does include images of human remains. I'm not going to be looking at all the stages of decomposition, but again, please don't take any photos of those particular slides. You're welcome to take any other pictures. First off, although this talk is just about the barrier to follow me, I wanted to note that this is part of a broader project that I initiated in 2014, and it has different tiers of collaboration. The two main other ones are working with the same donated human remains that I'm working on. One of them is a study of the effects of diagenesis and decomposition on isotopic composition of different tissues of the body, which is mainly for forensic applications, identification purposes, and the other is a proteomic study, again on the same human remains, with the aim to improve post-mortem interval estimation as well as age estimation. So you're aware that this is more than just the follow me component. So basically the aims of this part of the project is to examine and to test certain taffanomic models that are used in archaeo-sanitology. So as you are probably aware in this field, researchers are aiming to reconstruct mortuary practices and they're doing it by very carefully examining the specific position and relational bones within their burial environment. And there are two main models that are used in this field that I'm interested in assessing by studying actual decomposing bodies. And that is firstly the idea that there is this order and this articulation that Clara already spoke of, that certain bones, and we see the same image from the cruisal on the side here, that the bones disarticulate in a specific order, some of them earlier than others. And this idea that once the bones are disarticulated at the joints and they are free to move around if there is enough open space to do so, that that will lead to specific patterning in how the bones end up and how we recover them as archaeologists. So I set up an experiment where we can test the different variables that influence these processes in different posing remains. And I focused specifically on certain existing hypotheses in archaeo-sanitology. The first one is very closely related or overlapping with Clara which is great because we have comparative data. On primary and secondary open space around the body, primary being open space that was available once someone was buried. So for example the interior of coffin, secondary open space being space that is created or happens throughout the process of decomposition of the body. Then the effects of body position on the final pattern, the spatial pattern that we observe the bones in. And finally the notion that depending on the condition that the body is in when it's buried, whether it's fresh or mummified, the spatial distribution of the bones will differ and it will lead to a pattern that we can distinguish archaeologically. And these are things that are always interested in testing in actual decomposing cases. Now an important underlying premise of this study is that all stages but particularly the early stages of decomposition are hugely important in understanding funerary treatment, engagement and handling of the body of the people that survive the deceased. But it's also just as important if we want to understand the relation and the position of the bones as we find them in an archaeological burial. So if we really want to better understand burial toponomy then we also need to understand these very early stages of decomposition. So the experiment with the donated remains started in 2015 at the forensic anthropology center in Texas when I started receiving donated remains and broadly speaking there's two projects running at the same time. The first is a pilot study which included five human body donations which I placed in different positions with primary and secondary open spaces and in one case a modification and the rest as fresh burials. And the pilot study is used to assess the sequence of dysarticulation as well as how the bones are moving throughout the decomposition and then there's a longitudinal study alongside that that thus far has 25 human body donations and these are all placed on the surface of the ground in the same uniform body position. And the idea for those is almost as a check for the others to track the dysarticulation sequence in bodies in the same position. So data collection of the study for the dysarticulation sequence basically involved me observing the joints of the body on a daily basis and for the displacement of the bones over time I created 3D models using structure for motion photogrammetry at weekly intervals and then at the end of each experiment once the bones were cleaned and returned to the lab I created a 3D model of each individual bone of the body and we'll see why that's important later on. So just a very brief and I'm sorry I don't have time to go into all of these but please speak to me after. This is an overview of the five pilot study individuals and you'll see the variation in body position with donation one and donation three being in an upright seated position donation three is buried donation one was in an open pit we have donation four and donation two who were buried or either buried or in an open pit but flexed on the back and donation five is a mummification experiment who was later buried flexed on her back and she's still currently buried I will be excavating her in the spring of next year. So with regards to the finding and I'm really going to rush through this I'm very sorry but with regards to the findings on the disarticulation sequence one of the main outcomes of this study is essentially we're confirming what we already knew in archaeotematology that the body position affects the order of disarticulation and the process of disarticulation of the joints. So I noticed that very subtle sort of asymmetrical positioning of the body can lead to huge differences in disarticulation of the joints on either side so as an example you'll see here the right shoulder and the left shoulder and there's over a month in between now for an experiment that lasted just seven months that's a huge time difference between the the both sides of the body but I also like Clara saw a lot of reversals in this labile persistent joint connection so the so-called early disconnectors and the late disconnectors we see depending on the body different body position we see a huge difference in results. Another main thing that came out of this investigation is there are so many variables that affect the process of disarticulation just moisture body position obviously as we're speaking about this a lot but body mass index or how large is an individual the age and the health of the donor but hugely importantly insect activity. So fly larvae hatch into maggots and maggots can have a huge effect on the disconnection of the bone they can get into the joints and move apart the bones and eat away the connective tissues they will move around entire bones within an open space especially the smaller bones of the hands and feet so if you find a burial where the hands and feet are on the floor but they're completely distributed it's very likely that that is caused by insect activity and the problem with all of these variables is that they're acting on the body at the same time it's very hard to distinguish what is the result of one variable versus another and that leads to a problem with the models that we currently have because these are mostly based on archaeological barriers and in these archaeological barriers we have the end result of all of these variables acting on the body so it's very hard for us to then distinguish what is the result of what and that brings me to the accuracy of some of our current models as I said the insects are a huge factor that are currently not factored in so insect activity is hugely dependent on environment temperature access to the body wrapping body that kind of thing but I also noticed cases of re-articulation of the joints it doesn't happen frequently but depending on the position of the body bones can disconnect and later re-assume their approximate anatomical position which means if we would come along a thousand years later and excavate that burial we would never know that that disconnection took place meaning any models that we base on all the burials by de facto don't include that part of the process so we're not including everything. Then with regards to our findings my findings on bone displacement so the aims of this part of the project was to both visualize the movement of bones over time as well as to quantify them at once and my intention was to use the 3D models that I created every week and overlay these sequential models which allows you to then create heat maps and you know quantify the displacement over time that run into a lot of problems I mean it gives good results but if you look at this model on day 11 for doshik donation one you see there's a lot of missing data and that's because of the maggot mass moving around and things that move don't capture very well with the photogrammetry but if we then compare that day 11 to day 16 and then create a heat map you can see the green and yellow areas of the areas where there's the most difference between the two models but we're seeing the most difference where the soft tissue is reducing so that's just the natural part of decomposition and what we're actually interested in is what's happening to the skeleton underneath what's happening with these disconnections so we started looking for ways to visualize and quantify that so all we did is we visualized in a 3D animation and we quantified in 3D GIS and we took the weekly models that were created in the field and the models of each individual bone that I created afterwards and we basically refitted the skeleton into the human body which obviously requires a lot of good anatomical knowledge and then we were able to remove the field models leaving us with the position of the bones of the individual and then animate the steps in between so you see here the result of a work with Sarah Glushitz my co-author she did this as her master thesis and we used the photogrammetry models to animate in this case just the first two weeks of the experiment it's an ongoing project this lasted seven and a half months and we aim to animate the rest and give her her hands and feet because we don't have them in this model yet but it's really interesting to see this kind of movement of the body happening in the sort of sped up timeframe you can also see and we'll go into a zoomed in shot in a minute the different disconnections that are happening very early on and at the same time so here we'll see the neck area bear in mind this is someone who's seated upright and she's slumping forward and you'll start to see a disconnection occurring here between C4 and C5 and later we'll see because of this position South Colbert we're re-assuming their initial position and at the same time on day nine and ten we see the right hip is disconnected I'm very sorry but I have to skip through this if you want to see the rest so for the quantification of the movement we took this same model that we used for animation and brought it into a 3D GIS environment where we could then measure the distance between articulation points of the bones the hypothesis of this part of the project is that if we do this consistently in a large enough sample we might be able to identify signature this articulation patterns if they do indeed exist this would require a very large sample which is something that we hope to be able to do in the future so just to illustrate what I mean here is the same donation in the 3D GIS environment on day one of the experiment and day 216 which was the final day of the experiment in her case and if we just focus on her lower limbs we can see this is just an illustration these weren't the actual measurements but we can track you know connected joints this way and they're again on the last day and that would provide us for each joint of the body the distance in change between the start and the end of the experiment if we have this for a large enough sample of individuals in the same position we might be able to identify particular patterns for this slide all I want to say is again we need to replicate this this is hugely valuable information for how we interpret burials currently but in order to perhaps develop strong models from this we need to replicate it in other environments in a very large sample size as well and finally I just wanted to to note really the importance of this kind of actualistic experimental work in the field and we need more people becoming involved in this and more people doing this in different environmental conditions so we have a comparative data set because if we do have that we can improve existing taffanomic models that we have we have the opportunity to develop potentially new taffanomic models for example using the 3D GIS method and all of that taken together is hugely beneficial to archaeology mortuary archaeology but archaeology in general particularly when we're dealing with complex contexts such as mass graves but basically any situation where we want to extract as much information as possible in the shortest time possible thank you very much