Drafts

Both Selachains and batoids are considered Elasmobranchs, a subclass of the Chondrochtyes. Both of these fishes have cartilaginous skeletons and plated gills. Additionally both have placoid scales, which are similar in strucutre to teeth, giving them a rough sand-paper like skin. Since these groups are a subclass of elasmobranchs, they also have polydenton dentitions. That is to say there are many rows of replacable teeth.

Selachians include sharks. All sharks have 5-7 gill slits on the side of their head. These also have no swimbladder. Rather they rely on their large pectoral fins and oily livers to maintain bounency. Some sharks have the ability to osmoregulate, and can occupy a large range of ecosystems, marine or otherwise.

Batoids are fish such as rays and skates. These are dorsal ventrally flatened fish with pectoral fins fused to the side of their heads. Rather than having their gills on the side of their head, their gills are on located ventrally. Rays are viviporous and give birth to live young, while skaes are oviparous and lay eggs.

The Lecture that Peter Hotez presented on the rise of poverty related neglected diseases was eye-opening and intriguing. It was packed with information that I had never known and had changed my perspective on the way American organizations are handling global healthcare. Hotez introduced us to the previous eight global goals that had been published, in which three goals had involved healthcare improvement. One of the goals contained the idea of reducing HIV/AIDS, malaria, and “other diseases”. Hotez took it into his own hands to define the ambiguity within the statement: “other diseases”. He defined these diseases as tropical infections that were prevalent in poverty stricken communities. Hotez and his team then sought out ways to provide vaccinations to those in need in an efficient and cheap manner. Their team was able to fundraise over one billion dollars in order to research and act on the behalf of saving the lives of the poor from these infectious diseases. They were able to send large shipments of vaccines to non-healthcare professionals, such as teachers, to administer to people for only forty cents a person. This lead to an overall decrease in cases of almost every disease that a vaccine was provided for in these areas.

The cross bridge cycle is responsible for the contraction of muscles. The sarcomere is what actually contracts. A muslce is made up of myosin and actin. Actin is the thin filament and myosin is the thick filament. The muscle recieves a stimulus from a nerve cell that results in the release of calcium from an internal storage within the muscle. The increase of calcium concentration within the microfibules is what allows the cross bridge cycle to take place. The cross bridges cannot form without calcium because calcium is what allows the active sites to become exposed and without exposed acctive sites, the bridges cannot form. Calcium binds to troponin and as a result troponin changes it's shape. This shape change alters the positioning of the tropomyosin which exposes the active sites. The cross birdges then form. In the presence of calcium, the myosin binds to the actin. The next step is the powerstroke which is when the myosin head pivots, pulling the actin to the center of the sarcomere. ADP is released in this step. In the next step, ATP binds which triggers detachment. The cross bridge detaches as a result of atp hydrolysis. During the last step, ATP hydrolysis the myosin head is coked. The use of energy from ATP to ADP is used to rebind. This is one full cylce of the cross bridge cycle. 

There are two factors that are necessary in cross bridge formation. These two factors are an elevated concentration of calcium because cross bridges cannot form without calcium changing the shape of troponin. An adequate supply of ATP is also necessary becaue this proces requires energy. 

In the crossing of the mutant strands, there were fewer colonies observered than was expected on the control plate (one-hundred and fifty). This might have been due to a dilution error. For the MV plates, there were approximately ninety colonies observed. The reason for this proportion colonies may be due to not plating the same number of cells on the control plate as there should have been. Theoretically, there should have had a 20% survival rate if the optimal exposure was achieved. For the MV plate, the survival rate was 3.3%. This is significantly lower than expected and might be due to errors as mentioned above. There were no mutant phenotypically red colonies observed. This was expected, as you need about 10,000 surviving yeast cells for each mating type (3) to observe surviving mutant colonies that express a red color. The survival rate for our control plate was 6%. This was also much lower than the 20% expected survival rate, for reasons similar to the first plate. 

I am applying for the Aquarist Intern position for the Summer of 2018. I have heard about the Aquarium's internship program through several people at UMass Amherst and I am very interested in getting involved. I am a junior studying biology at UMass Amherst. I have taken classes at UMass Amherst that include hands-on labs and activities at Hadley Farm on campus. However, I am interested in getting additional exposure and experience working with animals and I think being an Aquarist Intern would give me that opportunity. Additionally, I am a pet owner and I have also done pet sitting and walking for family and friends. I volunteered at MSPCA's Nevins Farm, where I cleaned cages, fed animals, and walked dogs. Although I have never worked with aquatic life before, I have experience with other animals, am hard working, and open to learning new things.  I would love to schedule some time to discuss how my experiences, interests, and skills may be a good fit for the internship program at the New England Aquarium.

Figure 1. The original multi-panel figure of a spider-web, constructed by Marzia Maliha. Panel A consists of an open-street map showing the location of the spider web, Integrated Sciences Building, relative to its surrounding landmarks. The landmarks include buildings like Life Sciences Laboratories and nearby greeneries. Panel B shows a close-up of the spider web with a water bottle for scale. Panel C illustrates an overview of the surroundings of the spider web, a ‘No Smoking’ sign and a yellow Helpline box on the ISB brick wall.

Figure 2. The replicated multi-panel figure of the spider-web, constructed by Sophia Brownstein. Panel A consists of an open-street map showing the location of the spider web , Integrated Sciences Building, relative to its surrounding landmarks. The landmarks include buildings like Integrative Learning Center and nearby water bodies. Panel B shows a close-up of the spider web. Panel C shows the immediate surroundings of the spider web, including a ‘No Smoking’ sign and a yellow Helpline box.

Looking back at my statistics course, I realize that I mainly remember key concepts. For example, all of the basic measures including mean, median, mode. The idea of significance in a set of data is another element of statistics I recall. A confidence interval is essentially a measure of how confident you can be that the obtained result could be repeated. A confidence interval of .9 indicates 90% confidence and .99 indicates 99% confidence. If you have a very large sample and a high confidence interval, then you can more readily rely on the results. Also, a given sample size must have a minimum of thirty participants for results pertaining to it to be considered significant (n=30). All of these concepts can be related to the normal distribution. When conducting an experiment, you want to prove that your hypothesis actually generated a result. By using statistical analysis, you can provide a numeric confirmation that a difference was observed between an original condition and the experimental condition.