Differentiating Salmonid Migratory Ecotypes Through Stable Isotope Analysis of Collagen: Archaeological and Ecological Applications

The ability to distinguish between different migratory behaviours (e.g., anadromy and potamodromy) in fish can provide important insights into the ecology, evolution, and conservation of many aquatic species. We present a simple stable carbon isotope (δ13C) approach for distinguishing between sockeye (anadromous ocean migrants) and kokanee (potamodromous freshwater residents), two migratory ecotypes of Oncorhynchus nerka (Salmonidae) that is applicable throughout most of their range across coastal regions of the North Pacific Ocean. Analyses of kokanee (n = 239) and sockeye (n = 417) from 87 sites spanning the North Pacific (Russia to California) show that anadromous and potamodromous ecotypes are broadly distinguishable on the basis of the δ13C values of their scale and bone collagen. We present three case studies demonstrating how this approach can address questions in archaeology, archival, and conservation research. Relative to conventional methods for determining migratory status, which typically apply chemical analyses to otoliths or involve genetic analyses of tissues, the δ13C approach outlined here has the benefit of being non-lethal (when applied to scales), cost-effective, widely available commercially, and should be much more broadly accessible for addressing archaeological questions since the recovery of otoliths at archaeological sites is rare

An Experimental Pilot Study Into the Potential of Semi-crested Blades as Diagnostic Indicators of Core Preparation Method in Core-less Northwest Coast Microblade Assemblages

Two primary Early Holocene Northwest Coast microblade sub-traditions have been identified: the Campus/Denali complex, typified by bifacially prepared wedge-shaped microcores, and the Northwest Coast Variant style, represented by tabular or conical endscraper-like unifacial cores. The two complexes overlap both temporally and geographically, and with the relative paucity of cores recovered from microblade-bearing sites, further definition of techno-social boundaries is difficult. This paper presents the results of an experimental study to test the potential of the semi-crested blade, a regular product of microblade production, as a possible means of distinguishing between Campus/Denali and Northwest Coast Variant microblade assemblages where cores are ambiguous or absent

Open lithics : applying open source technologies to problems in lithic use wear experimentation and analysis

This dissertation presents and examines open-source methods and technologies for recording and quantifying aspects of gesture in lithic use experiments, as well as measuring and mapping edge damage on stone tools. It has three interrelated parts. The first presents two tools for quantifying components of gesture in lithic experiments: 1) OpenHaft, an electronic handle designed to measure and record the load exerted on a stone tool’s edge during use, and 2) cumulative stroke distance (CSD), to calculate the total volume of tool use during a task. An experiment using CSD and OpenHaft shows both distance and load to be major factors affecting wear on stone tools. The second part applies a suite of GIS (geographic information system) tools to precisely quantify and map “macrowear”—the chipping and flaking damage from tool use. 3D digital photogrammetry was used to produce digital surface models (DSM) of experimental microblades, that were compared using custom scripts for QGIS, yielding a precise record of the volume and location of material wear. This allows researchers to observe edge attrition throughout a tool’s use life. This is relevant to archaeological questions around tool design, curation, maintenance, and discard. The third part examines the viability of the QGIS edge wear analysis method on archaeological lithics based on an adaptation of Kuhn’s (1990) geometric index of unifacial reduction flaking (GIURF). To apply GIURF to archaeological lithics, it is necessary to virtually reconstruct the artifact in its pristine state, which this study attempts to do. Based on the experiment, GIS-automated GIURF does not yet virtually reconstruct worn lithics with enough accuracy for precise wear quantification, but successful reconstruction of some sections of worn microblades indicates promise for further development. OpenHaft/CSD and the QGIS wear quantification modules help lithic analysts to perform experiments with robust control over gesture variables, better defining what is a “stroke”, and precisely measure the effects of stroke variation on stone tools. The project applies the same GIS-based wear measurement methods to archaeological samples and offers a roadmap for future development. These open source techniques and technologies provide researchers with an accessible toolkit for better lithic experimentation and objective macrowear quantification and analysis.Arts, Faculty ofAnthropology, Department ofGraduat

Archaeological Survey of Dynamic Coastal Landscapes and Paleoshorelines: Locating Early Holocene Sites in the Prince Rupert Harbour Area, British Columbia, Canada

We present and test a predictive archaeological survey model that targets early Holocene paleoshorelines in the Prince Rupert Harbour area using LiDAR bare earth digital terrain models and a 15,000-year reconstructed history of relative sea level change. Despite a century of archaeological research in the study area, no sites dating earlier than 6000 cal b.p. had been identified prior to our research. Our field survey identified three early Holocene sites associated with paleoshorelines 7–10 m above current sea level (masl). These locations demonstrate repeated use through the Holocene even as shoreline position changes. We discuss these new data in relation to the early Holocene archaeological record from the rest of the northern Northwest Coast and suggest that the region was ubiquitously occupied by this time and that the lack of recorded early Holocene sites in some areas is likely a result of survey and preservation bias, rather than historical reality

Auditory temporal order discrimination and backward recognition masking in adults with dyslexia

The ability of 20 adult dyslexic readers to extract frequency information from successive tone pairs was compared with that of IQ-matched controls using temporal order discrimination and auditory backward recognition masking (ABRM) tasks. In both paradigms, the interstimulus interval (ISI) between tones in a pair was either short (20 ms) or long (200 ms). Temporal order discrimination was better for both groups of listeners at long than at short ISIs, but no group differences in performance were observed at either ISI. Performance on the ABRM task was also better at long than at short ISIs and was influenced by variability in masker frequency and by the spectral proximity of target and masker. The only significant group difference was found in one condition of the ABRM task when the target-masker interval was 200 ms, but this difference was not reliable when the measure was of optimal performance. Moderate correlations were observed between auditory thresholds and phonological skill for the sample as a whole and within the dyslexic and control groups. However, although a small subgroup of dyslexic listeners with poor phonology was characterized by elevated thresholds across the auditory tasks, evidence for an association between auditory and phonological processing skills was weakened by the finding of a subgroup of control listeners with poor auditory processing and normal phonological processing skills

Identifying relevant biomarkers of brain injury from structural MRI: Validation using automated approaches in children with unilateral cerebral palsy

Previous studies have proposed that the early elucidation of brain injury from structural Magnetic Resonance Images (sMRI) is critical for the clinical assessment of children with cerebral palsy (CP). Although distinct aetiologies, including cortical maldevelopments, white and grey matter lesions and ventricular enlargement, have been categorised, these injuries are commonly only assessed in a qualitative fashion. As a result, sMRI remains relatively underexploited for clinical assessments, despite its widespread use. In this study, several automated and validated techniques to automatically quantify these three classes of injury were generated in a large cohort of children (n = 139) aged 5–17, including 95 children diagnosed with unilateral CP. Using a feature selection approach on a training data set (n = 97) to find severity of injury biomarkers predictive of clinical function (motor, cognitive, communicative and visual function), cortical shape and regional lesion burden were most often chosen associated with clinical function. Validating the best models on the unseen test data (n = 42), correlation values ranged between 0.545 and 0.795 (p < 0.008), indicating significant associations with clinical function. The measured prevalence of injury, including ventricular enlargement (70%), white and grey matter lesions (55%) and cortical malformations (30%), were similar to the prevalence observed in other cohorts of children with unilateral CP. These findings support the early characterisation of injury from sMRI into previously defined aetiologies as part of standard clinical assessment. Furthermore, the strong and significant association between quantifications of injury observed on structural MRI and multiple clinical scores accord with empirically established structure-function relationships