Search for: All records

Abstract AimCardiac fibrosis contributes to systolic and diastolic dysfunction and can disrupt electrical pathways in the heart. There are currently no therapies that prevent or reverse fibrosis in human cardiac disease. However, animals like freshwater turtles undergo seasonal remodeling of their hearts, demonstrating the plasticity of fibrotic remodeling. InTrachemys scripta, cold temperature affects cardiac load, suppresses metabolism, and triggers a cardiac remodeling response that includes fibrosis. MethodsWe investigated this remodeling using Fourier transform infrared (FTIR) imaging spectroscopy, together with functional assessment of muscle stiffness, and molecular, histological, and enzymatic analyses in control (25°C)T. scriptaand after 8 weeks of cold (5°C) acclimation. ResultsFTIR revealed an increase in absorption bands characteristic of protein, glycogen, and collagen following cold acclimation, with a corresponding decrease in bands characteristic of lipids and phosphates. Histology confirmed these responses. Functionally, micromechanical stiffness of the ventricle increased following cold exposure assessed via atomic force microscopy (AFM) and was associated with decreased activity of regulatory matrix metalloproteinases (MMPs) and increased expression of MMP inhibitors (TMPs) which regulate collagen deposition. ConclusionsBy defining the structural and metabolic underpinnings of the cold‐induced remodeling response in the turtle heart, we show commonalities between metabolic and fibrotic triggers of pathological remodeling in human cardiac disease. We propose the turtle ventricle as a novel model for studying the mechanisms underlying fibrotic and metabolic cardiac remodeling. 

{"Abstract":["Testing took place from January to June 2019 and included natural and built environment tests with an emphasis on obtaining loading data for a 10x10 array of structures in the inundation zone. Bare earth tests were conducted first to get baseline velocity and wave height data. Then, the array of structures was added to the inundation zone. In addition to the same velocity and wave height sensors used in the bare earth experiments, some of the structures recorded pressures, moments, and loads. Debris in the form of wood blocks was added to both the bare earth and array tests to see how it changed the results. Sea walls are often used as a form of protection from waves and storm surge, so a wall of varying lengths was added to the array tests. These 5 main basin setups correspond to the 5 events below. Many different conditions were tested for each of these experiments. The "ALL_Experimental_Trials" table in the Sensor Information Section describes the conditions of every trial of the experiment and must be used to understand the data in every event folder. Please see the report for details as well."]} 

Inundation from storms like Hurricanes Katrina and Sandy, and the 2011 East Japan tsunami, have caused catastrophic damage to coastal communities. Prediction of surge, wave, and tsunami flow transformation over the built and natural environment is essential in determining survival and failure of near-coast structures. However, unlike earthquake and wind hazards, overland flow event loading and damage often vary strongly at a parcel scale in built-up coastal regions due to the influence of nearby structures and vegetation on hydrodynamic transformation. Additionally, overland flow hydrodynamics and loading are presently treated using a variety of simplified methods (e.g. bare earth method) which introduce significant uncertainty and/or bias. This study describes an extensive series of large-scale experiments to create a comprehensive dataset of detailed hydrodynamics and forces on an array of coastal structures (representing buildings of a community on a barrier island) subject to the variability of storm waves, surge, and tsunami, incorporating the effect of overland flow, 3D flow alteration due to near-structure shielding, vegetation, waterborne debris, and building damage.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/EDLiEK6b64E