0000000001301812
AUTHOR
Ivan Calandra
showing 14 related works from this author
Evaluating the microscopic effect of brushing stone tools as a cleaning procedure
2020
Cleaning stone tool surfaces is a common procedure in lithic studies. The first step widely applied at any archeological site (and/or at field laboratories) is the gross removal of sediment from the surfaces of artifacts. Lithic surface alterations due to mechanical action applied in wet or dry cleaning regimes have never been examined at a microscopic scale. This could have important implications in traceology, as any modern surface modifications inflicted on archeological artifacts might compromise their functional interpretations. The current trend toward quantification of use-wear traces makes the testing even more important, as even slight, apparently invisible surface alterations migh…
Short-term occupations at high elevation during the Middle Paleolithic at Kalavan 2 (Republic of Armenia).
2021
The Armenian highlands encompasses rugged and environmentally diverse landscapes and is characterized by a mosaic of distinct ecological niches and large temperature gradients. Strong seasonal fluctuations in resource availability along topographic gradients likely prompted Pleistocene hominin groups to adapt by adjusting their mobility strategies. However, the role that elevated landscapes played in hunter-gatherer settlement systems during the Late Pleistocene (Middle Palaeolithic [MP]) remains poorly understood. At 1640 m above sea level, the MP site of Kalavan 2 (Armenia) is ideally positioned for testing hypotheses involving elevation-dependent seasonal mobility and subsistence strateg…
A versatile mechanized setup for controlled experiments in archeology
2020
Experimentation has always played an important role in archeology, in particular to create reference collections for use-wear studies. Different types of experiments can answer different questions; all types should therefore be combined to obtain a holistic view. In controlled experiments, some factors are tested, while the other factors are kept constant to improve the signal-to-noise ratio. Yet, controlled experiments have been conducted with variable degrees of control. Although they seem decoupled from archeological applications, mechanized experiments and the robust causal relationships they measure are critical to answer archeological questions like understanding the processes of use-…
Dietary divergence in space and time – Lessons from the dwarf-goat Myotragus balearicus (Pleisto-Holocene, Mallorca, Spain)
2013
8 pages; International audience; Newly colonised, isolated habitats, like islands, provide diverse niches to be filled and are prone to facilitate ecological separation which might lead to an adaptive radiation. Examples of such radiations can be found in the Mediterranean for the genera Candiacervus (Crete), Nesogoral (Sardinia) and Hoplitomeryx (Gargano). A different strategy to cope with limited resources on islands is generalism. We test whether populations of the endemic bovid Myotragus balearicus from two sites and Pleistocene as well as Holocene levels on Mallorca island displays ecological separation indicated by diet, or whether the species shifted its dietary trait towards general…
Feeding ecology and chewing mechanics in hoofed mammals: 3D tribology of enamel wear.
2013
11 pages; International audience; Large herbivorous mammals have evolved chewing systems capable of processing a large variety of structurally diverse foods. Three-dimensional (3D) surface texture parameters are applied to investigate wear mechanisms related to tooth morphology, food source, and chewing dynamics. We tested 46 industrial 3D surface texture parameters for their capability to robustly indicate specific biomechanics in two grazing (Blue Wildebeest and Grevy's Zebra) and two browsing (Giraffe and Black Rhinoceros) ungulate mammals. These species inhabit sub-Saharan Africa and represent foregut and hindgut fermenters. The results did not indicate a wavelength threshold that can c…
Why should traceology learn from dental microwear, and vice-versa?
2019
Dental and artifact microwear analyses have a lot in common regarding the questions they address, their developmental history and their issues. However, few paleontologists and archeologists are aware of this, and even those who are, do not take into account most of the methodological insights from the other field. In this focus article, we briefly review the main developmental steps of both methods, highlight how similar their histories are and how combining methodological developments can improve both research fields. In both cases, the traditional analyses have been strongly criticized mainly because of their subjectivity and their lack of repeatability and reproducibility. Quantitative …
Polish is quantitatively different on quartzite flakes used on different worked materials.
2020
Metrology has been successfully used in the last decade to quantify use-wear on stone tools. Such techniques have been mostly applied to fine-grained rocks (chert), while studies on coarse-grained raw materials have been relatively infrequent. In this study, confocal microscopy was employed to investigate polished surfaces on a coarse-grained lithology, quartzite. Wear originating from contact with five different worked materials were classified in a data-driven approach using machine learning. Two different classifiers, a decision tree and a support-vector machine, were used to assign the different textures to a worked material based on a selected number of parameters (Mean density of furr…
Evaluating the microscopic effect of brushing stone tools as a cleaning procedure [Python analysis]
2020
This upload includes the following files related to the Python analysis: Raw data as a XLSX table (brushing_v2.xlsx), i.e. results from R Script #1 (see https://doi.org/10.5281/zenodo.3632517) Python script of the whole analysis (RunEveryParameter.py) Convenience script for running RunEveryParameter.py in background and logging all output (RunSingleParametesBash.sh) Log file for output of sampling from the model for each parameter in a loop (logAll.txt) Jupyter notebooks of the analysis run on epLsar as an example (Notebook_SingleParameter.inpyb) and of a summary of the whole analysis (Notebook_Overview.ipynb), plus associated HTML output files (*.html) For each parameter: Full samples of p…
Polish is quantitatively different on quartzite flakes used on different worked materials [ConfoMap analysis]
2020
Each surface has been processed with two templates: 1) Extract two 50x50 µm sub-areas and extract topography layer from each sub-area. Export sub-areas as SUR files. File names start with "A35" or "VSH4". 2) Process all extracted sub-areas for quantitative analysis. File names start with "processing-quartzite-final". All ConfoMap templates are saved in MNT format (including all original and processed surfaces, as well as results). Each template has also been exported to a PDF file. Instructions to download all files at once are given here: https://doi.org/10.5281/zenodo.4011952 Additionally, the results of the second template are collated into "proce…
Evaluating the microscopic effect of brushing stone tools as a cleaning procedure [R analysis]
2020
This upload includes the following files related to the R analysis: - Raw data as a CSV table (brushing_v2.csv), i.e. results from the ConfoMap analysis (see https://doi.org/10.5281/zenodo.3632490) - RStudio project (Brushing_project.Rproj) - R scripts as R Markdown files (*.Rmd) - Output from R scripts knitted to HTML files (*.html) - A text file containing the version of RStudio used (RStudioVersion.txt) Instructions to download all files at once are given here: https://doi.org/10.5281/zenodo.4011952
Polish is quantitatively different on quartzite flakes used on different worked materials [Python analysis]
2020
This upload includes the following files related to the Python analysis: 1. Raw data as a XLSX table (processing-quartzite-final-2020-04-29.xlsx) is the output from R Script #1 (see https://doi.org/10.5281/zenodo.3979139), even though the filename is slightly different. Plus, for each analysis (full and restricted datasets), included in the corresponding ZIP archive: 2. Jupyter notebooks of the analysis (Classification_RandSplitFeature_Revision_VXX.ipynb) rendered to HTML file (Classification_RandSplitFeature_Revision_VXX.html) 3. Dataframe including the artificially filled datapoints 4. Output of the analysis as PDF: • Confusion matrices ("CM&qu…
Evaluating the microscopic effect of brushing stone tools as a cleaning procedure [ConfoMap analysis]
2020
ConfoMap templates for each surface in MNT format (including all original and processed surfaces, as well as results). Each template has also been exported to a PDF file. Additionally, results are collated into 'brushing_v2.csv' Instructions to download all files at once are given here: https://doi.org/10.5281/zenodo.4011952
A versatile mechanized setup for controlled experiments in archeology [Electronic Supplementary Material]
2020
Supplementary Material 1. Preliminary tests on the Universal Robot UR5 (top) and inotec SMARTTESTER® (bottom). Each machine was programmed to move a scriber (needle) uni-directional linear motion from a starting point to an ending point (distance ≈ 19 cm) with a 50 N (UR5) or 5 kg (SMARTTESTER®) load applied onto the tip. One and five programmatically identical strokes were performed on an aluminum plate. The red dotted lines are straight lines drawn from the starting point to the end point. The arrows indicate the direction of the movement. The width of each groove was measured around the middle (where the black marks are) and are, from top to bottom: 407, 587, 814 and 961 &m…
Polish is quantitatively different on quartzite flakes used on different worked materials [R analysis]
2020
This upload includes the following files related to the R analysis: - Raw data as a CSV table (processing-quartzite-final.csv), i.e. results from the ConfoMap analysis (see https://doi.org/10.5281/zenodo.3979116) - RStudio project (Quantification quartzite final.Rproj) - R scripts as R Markdown files (*.Rmd) - R scripts knitted to HTML files (*.html) - An R script (RStudioVersion.R) to write the used version of RStudio to a text file (RStudioVersion.txt) - Output from script #1: processing-quartzite-final.Rbin and processing-quartzite-final.xlsx - Output from script #2: processing-quartzite-final_summary-stats.xlsx - Output from script #3: all plots as PDF files. Note that for running the s…