Kinematic Motion Patterns of the Cranial and Caudal Canine Cervical Spine

Objective: To define the kinematic motion patterns of the canine cervical spine, with a particular emphasis on identifying differences between the cranial (C₂–C₄) and caudal (C₅–C₇) segments, and to determine the significance of coupled motions (CM) in the canine cervical spine. Study Design: Cadaveric biomechanical study. Sample Population: Cervical spines of 8 Foxhounds. Methods: Spinal specimens were considered free of pathology based on radiographic, computed tomography, and magnetic resonance imaging examinations. All musculature was removed without damaging ligaments or joint capsules. Spines were mounted in a customized pure‐moment spine testing jig, and data were collected using an optoelectronic motion capture system. Range of motion, neutral zone and CM in flexion/extension, left/right lateral bending and left/right axial rotation were established. Data were analyzed using mixed‐effects maximum likelihood regression models. Results: Total flexion/extension did not change across the 4 levels. There was no difference between flexion and extension, and no CM was identified. Lateral bending was not different across levels, but tended to be greater in the cranial spine. Axial rotation was ～2.6 times greater in the caudal segments. Lateral bending and axial rotation were coupled. Conclusions: Kinematics of the cranial and caudal cervical spine differed markedly with greater mobility in the caudal cervical spine.     

Gamma ray inactivation of some animal viruses.

Twenty samples of animal viruses comprising 14 different viruses in 12 families were subjected to varying doses of gamma irradiation from a 60Co source in a Gamma Cell 220 (Atomic Energy of Canada Limited) to determine lethal dose levels. The dose responses appeared linear throughout inactivation. The D10 values, that is the dose necessary to reduce infectivity by one log10, ranged from less than 0.20 Megarads to approximately 0.55 Megarads. There was not a complete inverse correlation between the target size (virion core) and the D10 value.     

Where nothing stands still: quantifying nomadism in Australian arid-zone birds

Landscape Ecology - Nomadism is a movement strategy in response to non-seasonal environmental variability. Knowledge of nomadic species movements is poor but is necessary to understand life...