328 research outputs found
A Quantitative, Technology Independent, Fidelity Metric for Evaluating Bioprinted Patterned Co-cultures
The study of cell-cell interactions is crucial in the understanding of cell behaviors such as tumor genesis, proliferation, migration, metastasis, and apoptosis. To break down the complex web of signals in vivo, researchers must replicate some parts of this environment with in vitro tissue test systems, composed of multiple cell types arranged close enough to communicate with their neighbors, i.e. high-resolution co-culture patterns. The field of bioprinting is specifically focused on creating co-culture patterns for the purposes of cell studies, but the sample resolutions of most bioprinting systems are still too coarse to permit cell communication. No way currently exists to compare the sample fidelity between the technologies that have succeeded in creating high-resolution co-culture patterns.. This work introduces a quantitative metric for measuring co-culture patterning fidelity for use in comparing systems or tracking changes in fidelity with experiment conditions. The \u27biopatterning fidelity index\u27 (BFI) measures the performance of a system by fitting a scaled mask of the sample pattern over an image of the printed pattern and classifying the cells as correctly or incorrectly placed. A simple model is also introduced to provide a theoretical upper bound on the expected fidelity. The BFI and model were used to assess the performance of a custom bioprinter system. The performance of the system varied between the different cell types. The results indicate that the post-processing procedures were disturbing the fidelity of the patterns. New procedures should be developed that would not disturb the initial pattern fidelity. The best samples came very close to the model\u27s predicted upper bound. As the number of capable technologies increases, the BFI will provide a quantitative, technology-independent method to assess the fidelity of patterned co-cultures. The last section of this work examines the ability of the bioprinting system to create multiple slides of samples with similar cell distributions. It was shown that cartridges which had been exposed to less usage and cleaning had a more consistent cell output, enabling the bioprinting system to create biological comparable samples
Exercise in hispanic patients with diabetes
BACKGROUND - Obesity and physical inactivity are major risk factors in the development and progression of type 2 diabetes mellitus. Hispanic patients face barriers with language and culture in dealing with diabetes. At a Utah Community Health Center (CHC), patients needed a successful way to overcome these barriers in order to implement an exercise routine. METHODS - We prepared a Spanish language exercise DVD and distributed it free of charge to 40 overweight Hispanic patients with diabetes. Patients were given the exercise DVD as a part of a nutrition and exercise program in a 6-week study. Patients were contacted by telephone after 1 to 3 weeks to determine whether they were using the DVD. After 5-8 weeks the patients returned to clinic to be re-weighed. Patients were asked how often and how long they exercised and whether they found the Spanish language exercise DVD was helpful. RESULTS -Forty patients were evaluated. Six patients were lost to follow-up due to lost DVD, broken DVD player, or disconnected phone number. Thirty-four patients were included in the analysis. Thirteen patients showed an increase in the frequency of physical activity, 6 patients had a decrease, and 15 patients had no change in the frequency of physical activity. Fourteen patients showed an increase in the amount of time dedicated to physical activity, 2 patients showed a decrease. Eighteen patients did not change the time dedicated to physical activity and 25 patients showed a reduction in weight from baseline. CONCLUSION - Use of a Spanish language exercise DVD in a Hispanic population moderately improves frequency of physical activity, time dedicated to physical activity, and weight control
Designing a Minimal-Knowledge Controller to Achieve Fast, Stable Growth for Recombinant Escherichia coli Cultures
The biopharmaceutical industry is constantly developing new recombinant Es-cherichia coli strains to bring new products to market. In early stages of development, small scale bioreactors are used to make the product and explore di˙erent growth pro-tocols. Researchers spend significant time finding a feed rate profile that will give fast growth and low byproduct accumulation. The objective for the controller pre-sented in this work is to achieve fast growth and low acetate accumulation for an E.coli fermentation. The controller does not rely on previous characterization data or models but on fundamental metabolic relationships between oxygen and glucose as dictated by the Crabtree e˙ect. The controller senses metabolic state using an on-line oxygen uptake rate (OUR) estimate and pushes the culture to the boundary of oxidative and overflow metabolism (BOOM). A simulated E.coli culture and biore-actor were constructed to test controller performance. Fermentation experiments compared the BOOM controller to an Exponential feed and a DO-stat controller. Using minimal knowledge about the strain, the BOOM controller kept an induced E.coli MG1655 pTVP1GFP strain growing near the boundary of oxidative and over-flow metabolism. The BOOM controller produced more recombinant protein than the Exponential feed controller and the DO-stat controller, even though the growth rate used by the Exponential feed controller was extensively researched by a previous group. In another fermentation, the temperature was lowered to incur a fast change in the E.coli metabolism. In all experiments, the BOOM controller demonstrated it could maintain fast growth and avoid inhibitory acetate concentrations while requir-ing minimal knowledge of theE.coli MG1655 pTVP1GFP strain. For laboratories which deal with many di˙erent strains and proteins, the BOOM controller would maximize protein production and speed up protocol development
A Fast Approximate Approach to Microlensing Survey Analysis
Microlensing can be used to discover exoplanets of a wide range of masses
with orbits beyond ~ 1 AU, and even free-floating planets. The WFIRST mission
will use microlensing to discover approximately 1600 planets by monitoring ~100
million stars to find ~50000 microlensing events. Modelling each microlensing
event, especially the ones involving two or more lenses, is typically
complicated and time-consuming, and analyzing thousands of WFIRST microlensing
events is possibly infeasible using current methods. Here, we present an
algorithm that is able to rapidly evaluate thousands of simulated WFIRST
binary-lens microlensing light curves, returning an estimate for the physical
parameters of the lens systems. We find that this algorithm can recover
projected separations between the planet and the star very well for
low-mass-ratio events, and can also estimate mass ratios within an order of
magnitude for events with wide and close caustic topologies.Comment: 18 pages, 14 figures, Submitted to AAS journal
Powered Wheelchair Platform for Assistive Technology Development
Literature shows that numerous wheelchair platforms, of various complexities, have been developed and evaluated for Assistive Technology purposes. However there has been little consideration to providing researchers with an embedded system which is fully compatible, and communicates seamlessly with current manufacturer's wheelchair systems. We present our powered wheelchair platform which allows researchers to mount various inertial and environment sensors, and run guidance and navigation algorithms which can modify the human desired joystick trajectory, so as to assist users with negotiating obstacles, and moving from room to room. We are also able to directly access other currently manufactured human input devices and integrate new and novel input devices into the powered wheelchair platform for clinical and research assessment
Highly efficient Localisation utilising Weightless neural systems
Efficient localisation is a highly desirable property for an autonomous navigation system. Weightless neural networks offer a real-time approach to robotics applications by reducing hardware and software requirements for pattern recognition techniques. Such networks offer the potential for objects, structures, routes and locations to be easily identified and maps constructed from fused limited sensor data as information becomes available. We show that in the absence of concise and complex information, localisation can be obtained using simple algorithms from data with inherent uncertainties using a combination of Genetic Algorithm techniques applied to a Weightless Neural Architecture
Experimental exploration of the optomechanical attractor diagram and its dynamics
We demonstrate experimental exploration of the attractor diagram of an
optomechanical system where the optical forces compensate for the mechanical
losses. In this case stable self-induced oscillations occur but only for
specific mirror amplitudes and laser detunings. We demonstrate that we can
amplify the mechanical mode to an amplitude 500 times larger than the thermal
amplitude at 300K. The lack of unstable or chaotic motion allows us to
manipulate our system into a non-trivial steady state and explore the dynamics
of self-induced oscillations in great detail.Comment: 6 pages, 4 figure
Developing Effective Intelligent Assistance for the Powered Wheelchair User
This research is working towards developing a pre-production prototype system which can provide a low-cost real-time adjustable and adaptable driving assistance system for powered wheelchair users. Currently we are seeking to obtain information from user joystick input and their driving quality to identify symptoms and make adjustments to the driving assistance system
Inertial Sensor based Quantitative Assessment of Upper Limb Range of Motion and Functionality before and after Botulinum Toxin: A Pilot Study
Botulinum toxin (BTX) treatment of upper limb is considered effective for upper limb spasticity following stroke and brain injury. Traditional method - Modified Ashworth Scale (MAS) is widely used for assessment of spasticity, however, it suffers from limitations including the lack of objective outcome measures and ignorance of the active movements. This pilot study is to develop a quantitative assessment utilizing inertial sensors tool for upper limb movement measurement and to investigate an objective measure of upper limb function for neurological patients before and after BTX treatment of spasticity. The system we proposed provides kinematic measurements of upper limb segment and joint motion data. In this study, four stroke patients were assessed by our proposed inertial sensing system immediately before and one week after BTX injection. In addition, patients were assessed using clinical assessment scales e.g. MAS, Disability Assessment Scale (DAS) and Motor Assessment Scale. The results showed that elbow Active Range of Motion (AROM) increased by 19 degrees on average and MAS and Motor Assessment Scale scores did not show significant change. The changes of the kinematic measures for patients 1-3 e.g. AROM, Rate of change of elbow joint angle, NJS, MUN and S-ratio all show that the inertial system is able to identify improvement in performance. This inertial sensing system provides additional and novel dynamic motion data for a sensitive and quantitative assessment of response to treatment and the efficacy of post-injection physiotherapy
Low Cost Inertial Sensors for the Motion Track-ing and Orientation Estimation of Human Upper Limbs in Neurological Rehabilitation
This paper presents the feasibility of utilizing low cost inertial sensors such as those found in Sony Move, Nintendo Wii (Wii Remote with Wii MotionPlus) and smartphones for upper limb motion mon-itoring in neurorehabilitation. Kalman and complementary filters based on data fusion are used to estimate sensor 3D orientation. Furthermore, a two-segment kinematic model was developed to estimate limb segment position tracking. Performance has been compared with a high-accuracy measurement system using the Xsens MTx. The experimental results show that Sony Move, Wii and smartphones can be used for measuring upper limb orientation, while Sony Move and smartphones can also be used for specific applications of upper limb segment joint orientation and position tracking during neurorehabilitation. Sony Move’s accuracy is within 1.5° for Roll and Pitch and 2.5° for Yaw and position tracking to within 0.5 cm over a 10 cm movement. This accuracy in measurement is thought to be adequate for upper limb orientation and position tracking. Low cost inertial sensors can be used for the accurate assessment/measurement of upper limb movement of patients with neurological disorders and also makes it a low cost replacement for upper limb motion measurements. The low cost inertial sensing systems were shown to be able to accurately measure upper limb joint orienta-tion and position during neurorehabilitation
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