Author: Gillian

Internship – Ali Hoekstra

Published on by Gillian

During spring, I had the opportunity to do a 10 week research assistant internship at Teesside University. The experience has been both challenging and rewarding, offering a real-world glimpse into the kind of work I would like to pursue with my Forensic Science degree.

My main focus was a research project investigating ancient Roman leather scraps recovered from the Vindolanda archaeological site, which involved the use of a variety of advanced analytical tools. I worked with equipment such as Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), Visual Spectral Comparitor (VSC) as well as a SpecimIQ Hyperspectral Camera. Through this I developed skills in analytical techniques and even created my own protocols for certain parts of the project.

The SEM can be used to see things that are very very small and there is a whole world that you would not expect to see when you are looking so closely.

Zooming into the archaeological leather samples there is a landscape of texture and contours. Deep caverns open up and suddenly what with the naked eye was just a pattern, is a network of pores and skin creases. In the pores you find a collection of debris, presumably from where the samples had been buried,but move in closer and you might find evidence of single celled creatures with a silica cell wall – diatoms.

In the modern leather samples occasionally the roots of hairs were still in place even after going through the tanning processes. In some cases entire networks of mould had started to appear.

One of the biggest challenges was working independently and learning to troubleshoot issues on my own. This pushed me to become more self-reliant and confident in the lab. I also gained a clearer understanding of how scientific research works day-to-day, which has helped shape my thinking about future career paths.

I’m incredibly grateful to my supervisor and the lab technicians for their guidance and support throughout the internship. Their mentorship made a big difference and contributed greatly to what I took away from the experience.

Scanning Electron Microscope

Published on by Gillian

In one of our laboratories we have access to the TM4000III scanning electron microscope. It is the perfect instrument to take a closer look at artefacts, not only a scanning electron microscope but can also conduct elemental analysis – EDX. The system has 4 acceleration voltages, 5, 10, 15 and 20kV, viewing to 10× – 100,000× (Photographic magnification) and 25× – 250,000× (monitor display magnification).

We have recently been investigating collagen in archaeological leather..the image below shows the bundles of collagen strands seen in a modern leather sample.

New paper: Determining the impact of elemental composition on the long-term survival of vegetable-tanned leather in archaeological environments

Published on by Gillian

Very pleased that a paper that took an enormous amount of setting up, monitoring and determination has finally been published in Archaeometry.

The rather  long title is ‘Determining the impact of elemental composition on the long-term survival of vegetable-tanned leather in archaeological environments.‘

This paper started as what do we understand about leather degradation, to how we can look at this in the laboratory into a full scale microcosm set up in the laboratory. Helga set up and monitored these systems, each having a different variable, coupled with multiple variables of leather types.. it was a spreadsheet nightmare..

Abstract

This research paper investigated whether elemental analysis can differentiate leather manufacturing from soil contamination and whether soil hydrology and elemental composition impact degradation of leather. Portable X-ray fluorescence (pXRF) is a quick method for monitoring large-scale changes and groupings of aggregate inorganic elemental signatures, as well as influx of soil-based elements into the leather samples. Soil elements appeared to leach into vegetable-tanned leather within 2 months of burial, following pathways that are primarily dictated by soil hydrology (acidity, redox and saturation). Leather stability was also traced to elemental concentrations prior to burial, most likely introduced through the tanning liquid, and via a contributory factor of perimineralisation in the soil.

Pint of Science 2025

Published on by Gillian

I really enjoy public outreach and there is no better way than the pint of science events, held in May every year.

This year, I was asked to do a talk for the Darlington Pint of Science event and I dreamt up the title of ‘Leather – the plastic of the roman era’. Firstly, I love archaeological leather and second, I love the romans! I am not quite sure what I was thinking when i dreamt up the title, but I think my thoughts were around the the large amount of leather which still survives today, and thinking about how romans used leather, then linking that to what will people find from us in 2000 years!

We went on a rollercoaster during the talk, from different shoes, to what you would take camping, and then explored how you could differentiate leather species using mass spectrometry.. that is alot in 20 mins!

Pleasure to be on the stage with Dr Caroline Orr and Dr Zoe Bell

Environmental Monitoring – Vindolanda

Published on by Gillian

In 2021 we started a journey of environmental monitoring at Vindolanda. The journey started with questions on what was happening across the site many years earlier, but the decision taken by the Vindolanda Trust to fully engaged in continuous environmental monitoring was bold and forward thinking.

I joined the Trustee board  in 2022 and followed the journey as projects have developed, including around climate change and art, artefact degradation and how this has impacted and shaped the strategic plan for the trust 2024-2034.

It was an absolute pleasure to see the new west gate entrance, where the underpinning science is presented to the public, through the amazing design capabilities of the Vindolanda trust staff.

2024 – more than 150 unprecedented climate disasters

Published on by Gillian

Two posts about climate in one day.. but it is that important for us to look at..

Publications of the ‘state of the global climate 2024’ today the 19th march
Key messages
  • Key climate change indicators again reach record levels
  • Long-term warming (averaged over decades) remains below 1.5°C
  • Sea-level rise and ocean warming irreversible for hundreds of years
  • Record greenhouse gas concentrations combined with El Niño and other factors to drive 2024 record heat
  • Early warnings and climate services are vital to protect communities and economies

This is a sobering yet fantastic read: state of the climate report 2024

There is a short commentary here – Floods, heatwaves and supercharged hurricanes occurred in hottest climate human society has ever experienced

Image: Coastal side of Skara Brae – Neolithic houses on a very exposed site, susceptible to coastal erosion

Internship – Thenigha

Published on by Gillian

In 2024, the laboratory had the pleasure of hosting Thenigha Suriyakumaran for a 6 month internship. Thenigha was able to develop skills in many different techniques, including chromatography, mass spectrometry, pxrf and elemental analysis, enhancing her CV, however, the most important learning aspect was seeing how an active and busy research laboratory operates.

If you are unsure about where you want to go, have a look at: https://www.tees.ac.uk/sections/stud/   There is loads of support available.

BBC Radio 3: Vindolanda Leather

Published on by Gillian

What I love about my job is the range of people I meet and the interest in my laboratory work.. had a lovely chat with Rose Ferraby who is the creator of the series Earthwork on BBC Radio 3. Rose was interested in our leather research work, this is conducted with Dr Elizabeth Greene, Western Ontaro. The chat was transcribed into a great programme which is part of the Earthworks series.. highly recommended for a 15 minutes break and a cup of tea.

The series of EarthWorks  aired the other week, but still available online

The link to the series is here: https://www.bbc.co.uk/programmes/m0015v2l/broadcasts/upcoming

The link to your episode is here: https://www.bbc.co.uk/programmes/m0026ykc

And the link to previous series of EarthWorks here: https://www.bbc.co.uk/programmes/m0015v2l/episodes/player

We all love leather shoes right…

New paper

Published on by Gillian

I know it has been a busy start to the new year.. second paper of the year..

This new paper, marks the last of the thesis paper from Dr C Bisker, Comparative soil bacterial metabarcoding after aboveground vs. subsurface decomposition of Mus musculus

Link: Comparative soil bacterial metabarcoding after aboveground vs. subsurface decomposition of Mus musculus | Scientific Reports

Abstract

Outdoor microcosms, metabarcoding with next-generation sequencing of the 16S rRNA bacterial gene, total body score (TBS) and physicochemical analyses were used to monitor Mus musculus decomposition aboveground (A) and in the subsurface (S), and compared to soil-only controls (C). As determined by MaAsLin2 analysis, significant shifts in bacterial communities at 30 cm depths within the A, S and C treatments distinguished control from experimental soils, and between aboveground and subsurface deposition, demonstrating the potential for gravesoil discrimination during the first 90 days. For example, Dokdonella (p = 0.0002), Edaphobaculum (p = 0.0004) and Lacibacter (p = 0.0034) recorded significant shifts relative to sampling time. Furthermore, Massilia (p = 0.0005), Mycobacterium (p = 0.0006) and Sandaracinus (p = 0.0007) increased in abundance for the aboveground mice treatments. This was confirmed with ANOSIM where p = 0.0082 showed statistically significant difference between the aboveground and subsurface deposition. TBS and physicochemical analyses suggested that nutrient release into the soils occurred during active decay and skin rapture on days 7–13 in the subsurface and days 13–20 aboveground, with a particular increase in soil potassium concentration on day 15. Significant differences in soil temperatures resulted between A and S vs. C microcosms, aligning with atmospheric temperature changes. In summary, complementary application of metabarcoding, total body score, exogenous and physicochemical methods for postmortem interval estimation and clandestine grave location highlighted the feasibility of using temperature records downloaded from meteorological stations and portable X-ray fluorescence as indicators for various phases of decomposition.