Flexural properties of the equine hoof wall

The equine hoof wall is a hard keratinous structure which transmits forces generated when the hoof contacts the ground to the skeleton of the horse. During locomotion, the hoof capsule is known to yield under impact resulting in an inward curvature of the dorsal wall and expansion of the heels. However, whilst researchers have studied the tensile and compressive properties of the hoof wall, there is a lack of data on the flexural properties in different locations around the hoof capsule. In this study the flexural properties and hydration status of the hoof wall was investigated, in two orthogonal directions, in different locations around the hoof capsule. The hoof was divided into three regions: the dorsal-most aspect (toe); the medial and lateral regions (quarters) and the heels caudally. Beams were cut both perpendicular and parallel to the axis of the tubules, termed transverse and longitudinal beams respectively. Differences in the mechanical properties were then investigated using three-point bending tests. There were considerable differences in the mechanical properties around the hoof capsule; transverse beams from the toe were 81% stiffer and 28% stronger than those from the heels. This corresponded with differences in the hydration of the hoof wall; beams from the toe had a lower water content (24.1±0.25%) than those from the heels (28.3±0.37%). Differences in the flexural properties are thought to be largely a result of variation in the water content. Mechanical data are further discussed in relation to variation in the structure and loading of the hoof wall

Regional variation in the microhardness and mineral content of porcine long bones

Pig carcasses are frequently used as models for the human cadaver in the study of trauma and wound patterns. Limited availability and ethical concerns over the use of human tissue has meant that porcine bone is often used as a substitute for human bone in such studies. However, there is a lack of comprehensive mechanical data to make informed decisions on the choice of model to account for variations in the age, sex and body mass. In this study, variation in the properties of cortical bone along the length of the porcine humerus and ulna, from five female pigs aged over 36 months, was investigated by using Vickers microhardness tests. Transverse sections were taken from the proximal, mid and distal regions of the diaphyses, and tests were carried out in the anterior, medial, posterior, and lateral quadrants. Microhardness was also measured across the cortex from the periosteal to endosteal surfaces. Regional variation in mineral content was explored by analysing samples, taken immediately adjacent to the hardness tests, using Atomic Absorption Spectroscopy. Mechanical data are discussed in relation to mineral content, morphology and loading of the limbs, within a forensic context

Validation of PIRAT, a Novel Tool for Beam-Like Structures Subject to Seismic Induced Misalignment of Guiding Sleeves

International audienceThis paper is a comparison of analytical and numerical evaluations for a model system, which consists of a vertically suspended beam-like structure, guided by a pair of sleeves subjected to static or dynamic transverse displacements. The goal of these analyses is to evaluate and describe the mechanical behavior of such system during situations involving significant misalignment of the guiding sleeves, primarily caused by horizontal seismic vibrations. The analytical evaluation of the beam is performed using a solver in the novel tool PIRAT that incorporates the Bresse method to determine deflection shape and stress of the beam, where the numerical calibration uses a finite element solver called Cast3M. Both of these methods also investigate the evolving contact between the beam and its guiding sleeves (including a rigid lower sleeve and a semi-rigid upper sleeve) by an iterative algorithm to add additional contact zones / pressures to more realistically replicate the natural system. Illustrative computations are performed in order to verify that both methods are able to produce the same results / trends using a static deformation profile for the guiding sleeves. With the static models sufficiently validated and calibrated, the preliminary dynamic response of the system is presented. These are produced by replacing the static Bresse method with the dynamic Euler-Bernoulli equation of motion in the analytical framework. This is also compared to the dynamic capabilities of Cast3M, which relies on modal analysis, for validation. The work in this paper signifies the next step in developing a set of tools for considering dynamic responses to ensure the proper behavior of such systems during seismic activities through the use of analytical evaluations

Students as Partners in the Scholarship of Teaching and Learning

This essay reflects upon lessons learning from engaging students as partners in the scholarship of teaching and learning (SoTL). The project described here aimed to engage undergraduate students in SoTL research-based learning using the case study teaching method. Student partners were actively involved in synthesis of original case studies for teaching undergraduate biology, publishing and presenting this work to the public, and designing a research study to assess the effectiveness of case study teaching. Although largely successful, a number of challenges involving communication issues, time constraints, and project management were encountered. Based on the lessons learned from working through these challenges, tips are provided here that may be useful for in a variety of educational and research scenarios

Implications of the Information Technology Revolution for People with Disabilities

The paper focuses on opportunities for the integration of persons with different types of disabilities in the information technology (IT) labour market. Recent IT developments are identified and examined for their potentially harmful or beneficial effects on access to the IT labour market for persons with disabilities. The opportunities created by new job creation, new forms of training, teleworking, and the role of assistive technologies in facilitating workplace accommodations are briefly described. The focus is on new options for the design and implementation of computer-related assistive technologies in the workplace, and the impact of teleworking and the World Wide Web on employability and work-related training of persons with disabilities. The paper closes with a brief discussion of the roles that government agencies, business firms, labour unions, non-governmental organisations and education can play to help people with disabilities join the IT revolution and share its benefits

Case Study: Sick on a South American Sugarcane Plantation

A case study is presented that was designed to be used in high school and college level courses to familiarize students with chagas disease, its transmission, and effects in Central and South America. Noted objectives of the lesson include evaluating disease symptoms, examining socioeconomic factors related to the epidemiology, and creating visual aids with public health information. Questions are provided for discussing the a case of chagas disease at a Brazilian sugarcane plantation

Case Study: From Gummy Bears to Celery Stalks: Diffusion and Osmosis

The article describes a case study which interperses information on diffusion and osmosis with content review and knowledge application questions, as well as simple experiment that can be conducted without the use of a laboratory. Topics discussed include biological membranes, the use of gummy bears to demonstrate osmosis and osmosis in animal cells. Also mentioned is osmosis in plants. It notes that the case study was developed for use in an introductory undergraduate biology course

Interview with Ed Bonney by Andrea L’Hommedieu

Biographical NoteEdward Mason “Ed” Bonney was born April 5, 1933, in Buckfield, Maine, and grew up in Lisbon Falls, Maine. His parents, Mason Turner and Beatrice Evelyn (Dean) Bonney, were Roosevelt Democrats. Ed served four years in the Air Force and later became an air traffic controller in New York for several years. He and his wife moved back to Maine to raise their family and became involved in Maine Democratic politics. Ed served as chair of the Cumberland County Democratic Committee, where he first met George Mitchell, and later was executive director of the Maine Democratic Party when Mitchell was state chair. He served as executive director of the Maine State Bar Association for twenty-five years. SummaryInterview includes discussion of: family and educational background; WWII recollections; work as an air traffic controller; John F. Kennedy; involvement in Democratic politics in Maine; Mitchell’s time as chair of the Maine Democratic Party; Ken Curtis; description of George Mitchell in the late ‘60s; Severin Beliveau; Democratic National Convention (1968); Maine State Bar Association and continuing legal education; descriptions of Ed Muskie and George Mitchell; driving Senator Mitchell; and changes to the Maine Democratic Party

An Argument and Plan for Promoting the Teaching and Learning of Neglected Tropical Diseases

Neglected tropical diseases constitute a significant public health burden, affecting over one billion people globally, yet this group of diseases is underrepresented in the appropriation of both monetary and intellectual capital for developing improved therapies and public health campaigns. The topic of neglected tropical diseases has been similarly marginalized in the biology classrooms of our nation’s high schools and colleges, despite offering an opportunity to teach and learn about a diverse area of microbiology with far-reaching public health, social, and economic implications. Discussed herein is an argument for increasing the representation of neglected tropical diseases in microbiology education as a means to generate increased interest in these diseases among the generation of future researchers and policy-makers, and to promote interdisciplinary learning, civic engagement, and critical thinking