Experimental Characterization of Biological Tissue Mechanics

The function of ligaments and tendons is to transmit tensile forces, allowing healthy, bodily motion. However, if improper loading is placed on the tissue, the structures may rupture leading to pain, loss of function, and reduced quality of life. To prevent rupture, loads must remain below the ultimate strength of the tissue, but the maximum stress that the tissue can withstand varies due to several factors such as age, sex, body temperature, loading history, hydration state, and strain rate. These factors can be tested in order to understand how they affect tissue failure risk. Therefore, the objective of our research is to design and develop a lab procedure for future students to complete that experimentally characterizes the biological tissue mechanics. Load carrying tissues can be characterized by their stress-strain behavior utilizing a tensile tester. Using the tensile tester, the lab will consist of several experimental tests: freeze thaw cycles, varying strain rates, stress relaxation, and varying hydration. Creating a lab procedure for these experiments will allow students to describe both the viscoelastic properties of the tissue and the influences of strain rate on ultimate stress and ultimate strain. By measuring these quantities, we can gain a better understanding on the factors that affect tissue failure risk allowing for better treatment methods for injured athletes

Computational Simulations of Cell Diffusion in Matrix Environments

Scaffolds are frameworks that allow stem cells to differentiate into functional cells in order to generate new, healthy tissue to treat ligament and tendon injuries. We simulated stem cells migrating and differentiating throughout scaffolds to help us understand better design parameters of scaffold efficacy. Cells can create and place fibers as they proceed within the scaffold environment, so we hypothesize that cell diffusion will be confined when in a high local fiber fraction. We defined local fiber fraction as the percentage of fiber volume in a set field centered around the cell. We used MATLAB to simulate a 3D matrix environment in order to determine the mean square displacement (MSD) of each cell. At the end of the simulation process, we compared MSD and fiber fraction over time. MSD plots indicate whether the cell experienced any displacement, underwent confinement, pure diffusion, or drift. Local fiber fraction plots display the density of fibers surrounding the cell with respect to time. The results of the simulation did not show a correlation between confinement and high fiber fraction. In the future, we will consider if the angle of the fibers affects the movement, or if a cell is constricted by the presence of another cell in future simulations

Exploring the Use of a Qualitative Behavioural Assessment Approach to Assess Emotional State of Calves in Rodeos

There are longstanding disagreements between the rodeo industry stakeholders and animal welfare advocates about the wellbeing of the animals used in events. The current study aims to determine whether qualitative behavioural assessment (QBA) is effective in identifying the emotional state of calves in so-called calf-roping events. Still images of calves captured from videos of calf-roping were shown to two groups: practitioners (n = 7) and students (n = 16). For each image, they scored (on a scale of 1–10) 12 descriptive terms—e.g., stressed, energetic, confused, frightened—based on how strongly they thought the animal was experiencing that emotion. Scores were analysed using Factor Analysis and Ordinal Logistic Regression models, while inter-rater reliability was assessed using Intra-Class Correlation Coefifcients. The same imagery (video and images) were analysed for behaviours associated with the calves’ ears, neck, legs and tail to develop a behavioural ethogram, which was analysed with Binary Logistic Regression and Anova wrapping. The students were also surveyed to assess their empathy towards animals. The chase phase attracted significantly higher scores for stressed (µ = 5.0, p \u3c 0.001), agitated (µ = 5.1, p \u3c 0.001), anxious (µ = 5.0, p \u3c 0.001) and frightened (µ = 5.0, p \u3c 0.001), and the behavioural ethogram revealed that calves commonly galloped (p \u3c 0.001) and held their tails rigidly during this phase (p = 0.010). In contrast, the recovery phase was characterised by significantly higher scores for calm (µ = 3.0, p \u3c 0.001), contented (µ = 2.7, p \u3c 0.001) and relieved (µ = 1.6, p \u3c 0.001), and calves moved slower (p \u3c 0.001) with more neutral ear positions (ears axial p = 0.008, ears forward p = 0.010). A clear pre- and post-rope effect was evident, showing that QBA indicated that calves were anxious while being chased and were relieved when they had been released. The survey data revealed that students who had more empathy for animals in pain and for those used in experiments were more empathetic towards calves during the chase phase. They felt that calves being chased were agitated, anxious, stressed, frightened and confused. These results confirm that QBA has the potential as a tool for assessing the welfare of animals used in rodeos

The power of at-line amino acid measurements for accelerated process and media development of a mAb-expressing CHO cell line

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Risk Prediction of the Diabetes Missing Million: Identifying Individuals at High Risk of Diabetes and Related Complications

Early diagnosis and effective management of type 2 diabetes (T2D) are crucial in reducing the risk of developing life-changing complications such as heart failure, stroke, kidney disease, blindness and amputation, which are also associated with significant costs for healthcare providers. However, as T2D symptoms often develop slowly it is not uncommon for people to live with T2D for years without being aware of their condition—commonly known as the undiagnosed missing million. By the time a diagnosis is received, many individuals will have already developed serious complications. While the existence of undiagnosed diabetes has long been recognised, wide-reaching awareness among the general public, clinicians and policymakers is lacking, and there is uncertainty in how best to identify high-risk individuals. In this article we have used consensus expert opinion alongside the available evidence, to provide support for the diabetes healthcare community regarding risk prediction of the missing million. Its purpose is to provide awareness of the risk factors for identifying individuals at high, moderate and low risk of T2D and T2D-related complications. The awareness of risk predictors, particularly in primary care, is important, so that appropriate steps can be taken to reduce the clinical and economic burden of T2D and its complications

A review of image-based simulation applications in high-value manufacturing

Image-Based Simulation (IBSim) is the process by which a digital representation of a real geometry is generated from image data for the purpose of performing a simulation with greater accuracy than with idealised Computer Aided Design (CAD) based simulations. Whilst IBSim originates in the biomedical field, the wider adoption of imaging for non-destructive testing and evaluation (NDT/NDE) within the High-Value Manufacturing (HVM) sector has allowed wider use of IBSim in recent years. IBSim is invaluable in scenarios where there exists a non-negligible variation between the ‘as designed’ and ‘as manufactured’ state of parts. It has also been used for characterisation of geometries too complex to accurately draw with CAD. IBSim simulations are unique to the geometry being imaged, therefore it is possible to perform part-specific virtual testing within batches of manufactured parts. This novel review presents the applications of IBSim within HVM, whereby HVM is the value provided by a manufactured part (or conversely the potential cost should the part fail) rather than the actual cost of manufacturing the part itself. Examples include fibre and aggregate composite materials, additive manufacturing, foams, and interface bonding such as welding. This review is divided into the following sections: Material Characterisation; Characterisation of Manufacturing Techniques; Impact of Deviations from Idealised Design Geometry on Product Design and Performance; Customisation and Personalisation of Products; IBSim in Biomimicry. Finally, conclusions are drawn, and observations made on future trends based on the current state of the literature

In vivo strain measurements in the human buttock during sitting using MR-based digital volume correlation

Advancements in systems for prevention and management of pressure ulcers require a more detailed understanding of the complex response of soft tissues to compressive loads. This study aimed at quantifying the progressive deformation of the buttock based on 3D measurements of soft tissue displacements from MR scans of 10 healthy subjects in a semi-recumbent position. Measurements were obtained using digital volume correlation (DVC) and released as a public dataset. A first parametric optimisation of the global registration step aimed at aligning skeletal elements showed acceptable values of Dice coefficient (around 80%). A second parametric optimisation on the deformable registration method showed errors of and against two simulated fields with magnitude and , respectively, generated with a finite element model of the buttock under sitting loads. Measurements allowed the quantification of the slide of the gluteus maximus away from the ischial tuberosity (IT, average 13.74 mm) that was only qualitatively identified in the literature, highlighting the importance of the ischial bursa in allowing sliding. Spatial evolution of the maximus shear strain on a path from the IT to the seating interface showed a peak of compression in the fat, close to the interface with the muscle. Obtained peak values were above the proposed damage threshold in the literature. Results in the study showed the complexity of the deformation of the soft tissues in the buttock and the need for further investigations aimed at isolating factors such as tissue geometry, duration and extent of load, sitting posture and tissue properties

AppReminders – a pilot feasibility randomized controlled trial of a memory aid app for people with acquired brain injury

Mobile phone reminding apps can be used by people with acquired brain injury (ABI) to compensate for memory impairments. This pilot feasibility trial aimed to establish the feasibility of a randomized controlled trial comparing reminder apps in an ABI community treatment setting. Adults with ABI and memory difficulty who completed the three-week baseline were randomized (n = 29) and allocated to Google Calendar or ApplTree app. Those who attended an intervention session (n = 21) watched a 30-minute video tutorial of the app then completed reminder setting assignments to ensure they could use the app. Guidance was given if needed from a clinician or researcher. Those who passed the app assignments (n = 19) completed a three-week follow up. Recruitment was lower than target (n = 50), retention rate was 65.5%, adherence rate was 73.7%. Qualitative feedback highlighted issues that may impact usability of reminding apps introduced within community brain injury rehabilitation. Feasibility results indicate a full trial would require 72 participants to demonstrate the minimally clinically important efficacy difference between apps, should a difference exist. Most participants (19 of 21) given an app could learn to use it with the short tutorial. Design features implemented in ApplTree have potential to improve the uptake and utility of reminding apps