sworkman's blog

This project was aimed to asses the water quality and pollution levels of Sylvan stream using Periphyton. Periphyton are a class of aquatic microorganisms that grow in shallow slow moving water; they typically survive in water that has low to moderate pollution. We set up contraptions in three locations of the stream  that would collect periphyton and we observed the populations under a microscope after one and two weeks. The first location had the least and we believe this is because it was the closest to campus and had higher pollution. The third spot fell in the middle and the second location had the most. Overall there was high amounts of growth on the slides so we're concluding that the stream does have moderate pollution, however the levels do increase closer to campus. 

The bar graphs in Fig. 3 and Fig. 5 show similar patterns in the periphyton populations found in the three locations between week one and week two. Location 1 had the least amount of periphyton with an average of 13.66 the first week and 17.67 the second week. Location 2 had the most with an average of 94.01 week one and 79 week two. And the third location falls in the middle with an average of 20.33 week one and 54.33 week two.

The pie charts in Fig. 4 and Fig. 6 show the distributions of the different types of periphyton found at the three locations. The distributions for location 1 are similar between both weeks with the difference of no oval periphyton found the second week. Location 2 shows more equal diversity between thin clear rectangles, small rectangles and slivers in the first week than in the second week where the majority is thin clear rectangles. And for location 3 there is a shift for less thin clear rectangles and more small rectangles and slivers.

We collected periphyton by allowing them to grow on glass slides. We took three microscope slides and sandwiched them together using rubber bands with poster board in between; this allowed room for water to run through and periphyton to grow on the slides. The contraptions were put into three spots in Sylvan stream roughly 100 meters apart. Two sets of slides were placed in each location; they were tied to a string attached to a stick in the ground next to the stream to secure them. The slides were submerged roughly 12 inches under the water.

We collected one set of the slides from each location after one week. We counted different species in a 2 mm diameter circle from all 9 slides under a microscope; the different species were put into five categories based on their shape which include, slivers, small tinted rectangles, small clear rectangles, large rectangles, and ovals. We collected the second sets after two weeks and performed the same counting technique for the slides.

We created two different types of graphs to display the data. We created a bar graph for each location showing the average number of species found on each slide. And we created a pie chart that shows the average proportion of each species at the three locations.

This study showed a strong method to show proof of concept. The results were conclusive in the fact that it showed movements such as reach and grasp can be restored in a patient with tetraplegia. The patient chosen had a high spinal cord injury that was eight years old; this proves that this method can be effective in severe cases and the results were from the use of the two systems, not residual function. The combination of the two systems is shown to be very effective and the electrodes being under the skin makes it easier to translate to clinical use.

The downside to this test is the expense and length of time it takes. The systems used require many surgeries to implant along with recovery time and lots of exercise to restore muscle strength before the actual tests begin. This experiment also is only a proof of concept; results for only one patient are shown so it is unknown if it would work for everyone.

Overall, the conclusion of this experiment is that restoration of movement can be successful using a combination of the FES and iBCIs systems. There were positive results for completing reach and grasp movements for this patient. Future experiments could explore how this translates to different patients with different types of injuries. The coding system could use modification since they claim a percentage of the failed attempts of movement were due to faults in this system. The feedback for these tests are solely visual so possible experiments could work on giving spatial and tactile feedback. This experiment is a large step in restoring movement so there are many possibilities moving forward.

This combination of systems proved to be very successful in regaining movement for the patient. In fig. 3A, the different movements are shown with the different muscle contractions. The dot plots show the success rate for virtual and real arm movement; it shows that the movement is above the possibility of chance. The virtual arm was shown to have quicker response, but this is probably due to the lack of strength in the muscles. The patient was given the task of drinking coffee which involved reaching and grasping; this test had success 11 out of 12 times. Fig. 4 shows this action along with the time it took to complete each stage of this function. For this task, the system was turned off to see if any function remained, but showed no movement, thus proving the success in movement is due to the two-part system.

This experiment was done over a long period of time. The patient had to get multiple surgeries for the implantation of the electrodes and needed a relatively long recovery time in between surgeries. A time line of the procedures done are shown in fig. 2A. Time was also taken to work on strengthening the muscles used; there was a long period after the injury, before the experiment, when the muscles were not used at all. Before trying to move his actual arm, the patient worked on visualizing the movement, then worked on moving a virtual reality arm. Fig. 2B shows the virtual reality arm and the movement he was trying to achieve. Fig 2C shows the different stages of visualizing the movements, then using the virtual arm to see the movements and the actual movement of the arm. And fig. 2D shows the brain activity correlated with the different movements for the virtual reality and real arm.

The method that was used involved intracortical brain-computer interfaces (iBCIs) implanted into the brain, which consisted of just under 200 microelectrodes connected to a neural decoder. This system translated the firing of action potentials and their frequency power into commands that were sent to the FES system. The functional electrical stimulation (FES) had electrodes under the skin on the muscle of the patient that would stimulate contraction when signaled. In this experiment, a mobile arm support was used against gravity and for abduction and adduction movements. Fig. 1A shows these systems attached to the patient. In fig. 1B, graphs are shown demonstrating the neural patterns recognized for different movements involving the extension and flexion.

This paper’s objective was to explore the possibility of restoring movement to a patient with tetraplegia from a high-cervical spinal cord injury. In experiments done previously, the patient usually had a lower and less severe injury so there was less loss of function. This experiment aimed to stimulate both a reach and grasp movement using a combination of iBCIs and FES systems. Patients with these injuries need constant aid so this is aimed to make the patient become self-sufficient.

                This experiment used a man with a severe spinal cord injury that occurred eight years before the testing. Its important to do these tests on humans because animals do not get these types of injuries and survive. The long period of time between injury and testing eliminates the possibility that the movement stimulated is a result of residual function in the muscles. The severity just shows how effective the systems are even with so much loss of function.

Diabetes Ketoacidosis (DKA) starts to express symptoms from the lack of the hormone insulin. When things are working normally, insulin delivers glucose (from food intake) into cells, where it can be converted into energy. But without enough insulin in the body, glucose accumulates in the blood, where it is of little use. Even though there is plenty of glucose around, it can't get into the cells to feed them. The body's response is to drive up blood glucose even more by spurring the liver to break down its glucose stores and to make additional glucose from scratch.

As the body tries to clear the surplus glucose out of its blood through urination, a person may become dangerously dehydrated. At the same time, the body starts to liquidate fat deposits for energy. Fat is indeed rich in energy, but breaking down these stockpiles produces acidic side products called ketones. In high enough concentrations, ketones become toxic by making the blood more acidic. This imbalance is the crux of DKA and gives this complication its name. This increase in blood acidity can severely disrupt the finely tuned chemical processes in your body that keep you living and healthy.

This paper’s objective was to explore the possibility of restoring movement to a patient with tetraplegia from a high-cervical spinal cord injury. In experiments done previously, the patient usually had a lower and less severe injury so there was less loss of function. This experiment aimed to stimulate both a reach and grasp movement using a combination of iBCIs and FES systems. Patients with these injuries need constant aid so this is an attempt to let the patient become self-sufficient. 

This experiment used a man with a severe spinal cord injury that occurred eight years before the testing. Its important to do these tests on humans because animals do not get these types of injuries and survive. The long period of time between injury and testing eliminates the possibility that the movement stimulated is a result of residual function in the muscles. The severity just shows how effective the systems are even with so much loss of function.