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Biology of Energy

Submitted by ncarbone on Thu, 04/18/2019 - 20:58

Management and economics of energy are important for fitness. Animals allocate resources for reproduction, growth, and maintenance. R type species have short life spans and lots of reproduction while K type species have long life spans and produce few offspring that they invest a lot of energy into. The rate of energy usage is also an important consideration. The rate of energy usage determines how quickly an organism will go through their stored resources and how much food is required to get from the environment. Organisms have unique physiological and anatomical traits that help them manage energy acquisition, storage, and utilization.

Literature Review Survey Question

Submitted by ncarbone on Thu, 04/18/2019 - 16:46

A Chinese biophysics researcher, He Jiankui, performed germline editing via CRISPR-CAS9 on human embryos in order to make them resistant to HIV. The procedure was done without consent to the babies of course and without the permission from the government. The issue with germline editing is that the effects of the genetic mutation on future generations in not yet known. Should germline gene editing be approved for preventing HIV in humans without confident knowledge in the effect on future generations? In other words is the immediate benefit of germline gene editing worth the potential cost of future generations?

 
 

Caloric Expenditure in Aerobic vs Resistance

Submitted by ncarbone on Sun, 04/14/2019 - 19:33

In a study performed by Falcone et al the caloric expenditure of aerobic and resistance exercises were compared. Subjects completed 4 different exercise interventions at different intensities for 30 minutes each. The four exercises consisted of weight training (squats, chest press, shoulder press, and seated row), treadmill running, stationary cycling, and a hydraulic resistance machine. Three were 9 participants whom were all male and between the ages of 18-35. Subjects were asked to consume the same food 48 hours before each session (12).

Triglycerides and Diabetes updated PP

Submitted by ncarbone on Thu, 04/11/2019 - 22:44

Triglycerides are also proposed to have an impact on the development of neuropathy. Triglycerides and obesity correlate with diabetic neuropathy independent of glucose control. Smith and Singleton found that obesity and triglycerides were related to small axon loss whereas hyperglycemia was related to large fiber loss indicating that hypertriglyceridemia and obesity have an independent effect on peripheral neuropathy (8). Wiggin et al analyzed samples from a double-blind placebo clinical trial with Acetyl-L-carnitine (ALC) at two doses.  Since the intervention had no effect, data from three arms (placebo, 1.5 and 3.0 gm doses) were combined.  The investigators found a correlation between elevated triglycerides and mixed small and large myelinated fiber density (MFD).   Further higher triglycerides were associated with those whose neuropathy progressed as evidenced by changes in MFD (9).

Ester Lab Discussion

Submitted by ncarbone on Wed, 04/10/2019 - 11:05

In this lab the starting materials (acetic acid and isopentyl alcohol) were reacted together. The refluxed solution never separated into two layers so the expected final product of isopentyl acetate was not found therefore there was no final weight or percent yield calculated. This could have been due to either a failure to mix the liquids well or from a frayed plastic connector piece in the distillation apparatus. In order to analyze the odor and IR spectroscopy another student’s product was used. The odor resembled a banana scent which is comparable to the expected odor of isopentyl acetate. The IR spectrum has a large dip around 1740cm-1 confirming the presence of an ester. However, there is also a large peak at about 3600cm-1 indicating some impurities in the product.

Fischer Esterification Lab

Submitted by ncarbone on Tue, 04/09/2019 - 22:45

0.75 mL of acetic acid and 1.20 mL of isopentyl alcohol were added to a round bottom flask. Four drops of concentrated sulfuric acid was carefully added to the flask before being refluxed in an air condensing distillation apparatus. The solution was boiled for 15 minutes and then the organic layer of the collected liquid was poured back into the round bottom flask and boiled for another 15 minutes. The process was repeated one more time for a total reflux time of 45 minutes. The solution was then cooled to room temperature and poured into a centrifuge tube with 1 mL of water. The solution was mixed and the bottom layer was removed to waste. 1 mL of sodium bicarbonate was used to rinse the solution and the aqueous layer was removed again. Then 1 mL of sodium chloride was used to rinse and the aqueous layer was again removed. Calcium chloride spheres were added to the solution and then the dry solution was moved into a tared vial were the odor was observed. Lastly, an IR test was performed to determine the purity and identity of the isopentyl acetate.

Tyrannosaurus was not a fast runner review: Pt. 4

Submitted by ncarbone on Tue, 04/09/2019 - 14:37

I thought that the authors did an excellent overall job of not only proposing a controversial hypothesis, but also backing up the hypothesis with real life data and calculations. I especially liked how they combined both factual data from living organisms and educated hypothetical data to construct and support their theory. The authors also provided detailed tables with their data along with figures to help illustrate some of the points that they were alluding to. Also, because some of the data that they came up with was hypothetical or estimated I thought it was a logical idea to underestimate their calculations. The one issue that I had with the paper was that the methods section was inserted at the end of the discussion. I would have liked to know the methods before reading their statistical results.

Tyrannosaurus was not a fast runner review: Pt. 3

Submitted by ncarbone on Tue, 04/09/2019 - 11:41

To further back up this claim the authors performed a parameter study to assess the sensitivity of their prediction. Mass was not the only important factor in determining their hypothesis. They also looked into limb orientation, and muscle fiber lengths. Since these data points cannot be determined for sure the authors used conservative assumptions leading to an underestimated value of required muscle mass. They used T as the minimum extensor muscle mass per leg and determined that if T  is 5-25% body mass per leg than the biped could not run fast due to the lack of necessary muscle force. Hutchinson and Garcia’s model predicted that the T value for Tyrannosaurus was between 10-21% per leg which is not adequate enough for it to be considered a fast runner.

Tyrannosaurus was not a fast runner review: Pt. 2

Submitted by ncarbone on Tue, 04/09/2019 - 11:29

Hutchinson and Garcia used data from extant animals to help support their claim. They looked at the muscle anatomy of different animal’s hips, knees, ankles, and toes in order to come up with a sufficient comparison to Tyrannosaurus. Also due to fossilized footprints they had data present for small tyrannosaurs. Other animals that were used in comparison include: alligators, chickens, and the extinct Colelophysis. In comparing the muscle percent of the alligator and the chicken they found that the chicken has a larger percent of muscle mass per body mass than alligators which allow them to run faster. This is due to scaling principles predicting that animals of larger body mass have a more restricted locomotor performance. In order for the Tyrannosaurus to be a fast runner it would need enough muscle mass to support its body the authors argue. The authors calculated that the dinosaur would need about 43% of its body mass to be muscles in each leg alone in order to be a fast runner.

Tyrannosaurus was not a fast runner review: Pt. 1

Submitted by ncarbone on Mon, 04/08/2019 - 21:39

In the reading by John R. Hutchinson and Mariano Garcia, the two authors propose a controversial concept that large theropod dinosaurs such as Tyrannosaurus were not actually fast runners. They use a method for gauging running through a model system that works for estimating the speed of living species such as alligator and chickens.The authors point out that this concept of Tyrannosaurus being a slow runner is not a new idea. There were earlier assessments based off of biomechanics that suggested the dinosaur was limited in locomotive performance. These early ideas were not widely accepted due to the uncertainty of the dinosaur’s anatomy, physiology, and overall behavior. However other previous studies estimate that Tyrannosaurus was able to run in the range of 11-20 m/s.

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