Browsing by Author "Du, Andrew, committee member"

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Open Access
Cut it out: a novel, quantifiable approach to kerf mark analysis using 3D confocal microscopy and machine learning
(Colorado State University. Libraries, 2023) Benson, Wyatt H., author; Pante, Michael C., advisor; Du, Andrew, committee member; Jackson, Jessica, committee member
Forensic methods must adhere to the Daubert standard to be deemed as admissible evidence in court. Current critiques regarding how well this standard is upheld have also challenged whether current forensic practices truly meet the Daubert standard. For example, kerf mark analyses can reveal trace evidence in sharp force trauma cases but a lack of quantitative studies and standardized analytical methods leave the field open to potential scrutiny. While previous research frequently classifies marks as either the product of serrated or non-serrated blades, further identifications are rarely made confidently. The goal of this project is to determine whether variations in 3D micromorphological variables can be used to quantitatively discriminate between kerf marks made by different knife types and blade classes. Here, kerf marks were produced using five different knives on bovid diaphyses, 3D scanned using profilometric microscopy, measured for both volumetric and profile variables, then analyzed using quadratic discriminant analysis. Results show individual knives were classified correctly in only 52% of attempts. However, blade class – serrated vs. non-serrated vs. partially serrated – was successfully identified in 97% of attempts. Significantly, our results differentiate between kerfs produced by serrated blades, non-serrated blades, and partially serrated blades, not only allowing for more specific blade identifications but also producing a quantifiable and replicable method meeting the Daubert criteria.
Open Access
Food and Black livingness in the South Carolina Midlands
(Colorado State University. Libraries, 2024) Ross, Reagan A., author; Chennault, Carrie, advisor; Du, Andrew, committee member; Attai, Nikolai, committee member
This thesis explores how food, food spaces, and food sharing practices play a role in the lives of Black women in Newberry County, South Carolina. In particular, it explores how power relations take shape at the intersection of southern foodways and Black geographies via the everyday and intimate practices in the lives of Black women and their communities. Using ethnographic methods informed by Black feminist and community-engaged methodologies, I collaborated with community members in Newberry County over the summer and winter of 2023 to document and examine how plantation histories have impacted intergenerational knowledge sharing and feelings of personal and community empowerment, and how community members rely on themselves and one another, particularly through food sharing practices, to defy ongoing systematic oppressions. Using a critical and Black feminist approach, the first empirical chapter explores the connection between creativity and care work in food sharing practices when examined as an expression of aesthetic labor. Looking to Black geographies and Black feminist scholarship, the second empirical chapter explores how community members employ self-intimacy and spirituality as intimate strategies of resistance and liberatory world-build in and through food spaces. The motivation for this thesis came first and foremost from the desires of community members to document and preserve their knowledges, particularly those related to food and its impact on their lives and communities. This research is also intended to contribute to geographic and critical food literature by calling into question the ways in which much of southern foodways and southern foodways scholarship have sought to erase Black geographies and, even more importantly, by centering Black life, livingness, and sense of place in food spaces.
Open Access
Unpacking the trunk: pelvic-thoracic relationships in modern Homo sapiens
(Colorado State University. Libraries, 2024) Shaw, Zoë G., author; Glantz, Michelle, advisor; Du, Andrew, committee member; Throckmorton, Zachary, committee member
It is generally accepted that throughout the history of the genus Homo, shifts in body morphology have aligned with the emergence of distinct hominin populations (Ruff, 1991, 1994, 2010; Schmid et al., 2013; Walker & Leakey, 1993). The human trunk, comprised of the ribcage, pelvis, and spine, contributes the most to overall body shape. However, how the thorax and pelvis are morphologically related in modern humans is not well understood. The fragmented nature of the human fossil record poses challenges in reconstructing the morphology of the trunk. Research on extant nonhuman ape morphology has suggested covariance between the inferior ribcage and upper pelvis, and it has been proposed that this pattern holds for premodern hominin groups (Schmid, 1983; Schmid et al., 2013). This expectation of covariance between the upper and lower portions of the trunk has allowed researchers to infer body shape and size with incomplete remains (Schmid, 1983; Schmid et al., 2013; Jellema et al., 1993). However, recent findings have served to challenge previously accepted trends in hominin body shape, calling into question whether the hominin trunk is integrated as was previously thought (Arsuaga et al., 1999; Day, 1971; Rosenberg, 2007; Simpson et al., 2008). The current study expands on previous work by Torres-Tamayo et al. (2018, 2020). Five linear measurements from a mixed sample of 85 living humans were taken from computed topography scans rendered in 3D. Results suggest a minimal correlation between pelvic dimensions and inferior ribcage width, with some variations observed by sex. Understanding this relationship in modern humans aids in evaluating researchers' expectations when interpreting past hominin body shapes and offers new insights into the origins of modern human and neandertal anatomy. Since evidence of integration is weak, results suggest that the thorax and pelvis may be under different selective pressures in modern H. sapiens.