Drafts

I have a microbiology exam tomorrow which I have yet to study for. There is way too much information to start now. We have to know a paper by someone who’s last name is Brenner, why we have to know a paper from the 50’s I have no idea. The paper is interesting, it is about proving that DNA codons are in triplets. He does this by doing a few math computations that are very simple. The only reason that the paper has any relevance is that he was the first to publish this thought. It didn’t prove anything about how codons work or their importance. It just proves that codes come in sets of 3 nucleic acids. This is a very informal paper and it almost just seems like the author typed up what he was just scribbling down on his desk one afternoon. I really don’t understand why we need this for our test and why this is important to the class that I am taking. I already know that codons are in sets of three, this has been repeatedly taught in almost all of my science courses since high school. The paper doesn’t even necessarily prove what codons are, it just proves that based off other properties that they most likely function in groups of 3.

From pure trimyristin, which was obtained from extraction, recrystallization and hydrolysis of nutmeg, myristic acid was synthesized in this lab. The yield of myristic acid is 34.5%.

    Recrystallization of trimyristin was processed twice and each melting point was recorded and observed. The tert-butyl methyl ether (3 mL) and nutmeg (1.000 g) were dissolved to obtain crude trimyristin that resulted in a 57.8% recovery yield (0.578 g). A 30.2% recovery yield, based on the original amount of nutmeg, was obtained from the trimyristin after the first recrystallization. The melting point of the first recrystallization was 53-54 ℃, which is 2℃ under the theoretical melting point. We can conclude from this that the product was relatively pure. A sample of trimyristin from the first recrystallization (0.167 g) was dissolved in a minimal amount of acetone in the second recrystallization in attempt to obtain a more pure product. A 49.1% recovery yield was obtained from the second recrystallization. The melting point recorded was 54-55℃, which is only 1℃ below the theoretical melting point and shows that the second recrystallized product is relatively pure.

Trypanosomiasis, human African sleeping sickness generally occurs in 36 sub-Saharan African countries. This disease is a vector-borne parasitic disease and is caused by an infection with protozoan parasites and transmitted to humans by the tsetse fly. This disease not only causes severe disruption in sleep patterns, but changes in behavior, confusion and without treatment the disease can ultimately lead to death. Health officials have reported about 1447 cases of African trypanosomiasis, but many believe that the true number of cases is believed to be much higher that what is reported. Treatments of the human African trypanosomiasis include drugs named eflornithine and nifurtimox, both treatments involve a complicated set of procedures including fusions and pills that are administered in a hospital. 

In the article, Potential winter niche partitioning between Tufted Titmice (Baeolophus bicolor) and Black-capped Chickadees (Poecile atricapillus) by Correia, black-capped Chickadee and the Tufted Titmouse competition was compared. Results show that Black-capped Chickadee tended to stay in the niche that was higher in ground than the Tufted Titmice that mostly done ground foraging. Since the Tufted Titmice is larger in size, it is hypothesized that Black-capped Chickadee avoided on purpose not to be on ground so that it would not have to compete. The data was collected by using a JC record to tape the behavior at the bird feeder. The location each bird stayed and forage was taken as data and the dot was used to tell how Black-capped Chickadee and Tufted Titmice interacted with each other.

The visual system of most deep sea organisms is able to detect short-wave blue wavelengths. Loosejaw dragonfish are able to detect longer wavelengths of light and emit these wavelengths as the color red through bioluminescence. The authors sought to understand the timing of the evolution, the number of times the trait evolved, and whether it arose due to positive selection. The findings for the evolution of the red visual system were more complex than expected. The red visual system was found to have evolved once as a single evolutionary event within loosejaws. They found that at approximately 15.4 Ma, far red visual systems evolved and at 11.2 Ma the primitive blue visual system re-appeared in the most recent common ancestor of dragonfish. The authors also investigate the phylogenetic relationships between Stomiidae and found that the relationship between this family and loosejaws is paraphyletic. The significance of this study in the context of spectral tuning in deep sea organisms is that it provides a phylogenetic approach to analyzing the evolution of the red visual system.

Metastatic pancreatic adenocarcinoma is driven by cancer stem cells, formation and upregulation of the premetastatic/metastatic niche, EMT, and the largely hypoxic state of the tumor microenvironment (TME). These characteristics of metastasis feed into each other continuously to further the development and distribution of the cancer. Cancer stem cells serve as the central driver of metastasis due to their inherent plasticities and contribute to chemoresistance, functioning of the premetastatic niche, and induction of EMT (Sancho et al. 2016). In the premetastatic niche, extracellular signaling contributes to a TME that facilitates the development of the cancer. EMT allows cancer cells to detach from a tumor site and relocalize, as well as change their phenotype to a less differentiated state. When tumor growth reaches a critical point, cancerous cells deprive their environments of oxygen, leading to hypoxia and potential metabolic shifts such as the Warburg effect or oxidative phosphorylation (Sancho et al. 2016).

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.

    Oxytocin is a hormone that is known as the “love hormone”. Oxytocin is released when acts of love and bonding occurs such as hugging. Oxytocin is secreted in high levels during breastfeeding and in relationships. Doctors started to prescribe oxytocin to children with autism, schizophrenia and social anxiety disorders. Oxytocin can change the intensity of the reaction but it would not be able to turn it on or off. Evidence has shown that women with high maternal care and strong relationships has shown high levels of oxytocin. Also there is a high level of oxytocin in women in depressive states and distressed relationships.