Drafts

Interdigital webbing is found among many vertebrates in the early stages of development. However, many of these organisms remove this webbing through tissue-specific apoptosis, removing the interdigital membrane back towards the digits. Some mammals retain this webbing, such as bats. This is feasible through inhibition of apoptosis, specifically through the BMP inhibitor Gremlin.¹ BMP signaling typically results in apoptosis in expressed tissues, but through Gre inhibition, these tissues remain and can be repurposed-in the case of bats-for flight.

(1) Weatherbee, S. D., Behringer, R. R., Rasweiler, J. J., & Niswander, L. A. (2006). Interdigital webbing retention in bat wings illustrates genetic changes underlying amniote limb diversification. Proceedings of the National Academy of Sciences, 103(41), 15103–15107. doi: 10.1073/pnas.0604934103  

The seed coat plays an important role in the growth, germination, and protection of the seed. In some plants, there is some evidence that the seed coat might inhibit the seed’s germination. Our study investigated whether the removal of the seed coat impacted the seed germination time. 

We studied 6 species:

• Whole green peas

• Barley

• Chickpeas

• Pinto beans 

• Baby lima beans 

• Green split beans

• Their seed coats were removed using an exacto knife and soaked in water for 1 hour. The seeds were then divided into groups, including the unremoved coat, which is the control. Finally, the seeds were checked every 12 hours and the state of the seeds was recorded.

A graph showing the germination of half the seeds over time shows that many seeds germinated slower without a coating. Time When Over Half of the Seeds Germinated. Comparison of the time when half of the seeds germinated. For barley, baby lima beans, and green split beans, intact seed coats germinated faster. Possible future experiments may lead towards figuring out how optimal germination rates vary by seed species.

In Boston, the bodies of water surrounding the city affect the temperature. The high specific heat of water causes it to cool and warm more slowly. Amherst not located in a coastal environment, but in an inland environment. This causes the temperature to be more moderate throughout the year.  The tilt of the Earth throughout the seasons causes changes in solar radiation. Amherst is located in the North Hemisphere and is affected based on the sun’s location coupled with the Earth’s tilt. In the summer, the sun is located above the Northern Hemisphere while in the winter the sun is located farther away. The tropics receive more direct solar energy causing a greater amount of evaporation than in areas of higher latitude. The air is also warmer in the tropics which causes it to rise and condense. This leads to the air retaining more water. 

There are multiple reasons that poles are cold. There is less daylight hours in the poles and the sunlight has a higher amount of reflection due to larger amounts of ice, snow and water. This causes heat to be reflected and lower the temperature of the air. In addition, there is less water vapor in the poles due to the lower temperature lowering the capacity for water to evaporate. Less moisture in the air allows energy in the form of heat to escape. The sun’s position around the poles causes the atmospheric length to be longer; leading to a lower amount of radiation actually reaching the surface. These factors lead to the air becoming colder.

In cancer studies, the changes of gene expression is what is concerning to scientists.  As a result, RNA is necessary to study changes in gene expression.  RNA is an extremly unstable molecule and it needs to be to ensure regulations of gene expression.  In order to study RNA effienctly, reverese transcription is used via reverse transcripase to create cDNA from the RNA template.  When the RNA is being studied, the introns have already been spliced out allowing for a precise understanding of the exact DNA sequence causing the regulation without introns interferring with it.  PCR can then be used to replicate the cDNA and allow for several copies of DNA to be used.  In PCR, there a phase where the reaction platues.  Therefore, there needs to be flourences and a window to see the levels of all the DNA to determine which sequences are amplyfying fastest.  Before the platue, the levels can be compared to see what gene is expressed most in the cancer cells.

PCR, polymerase chain reation, is used to create replications of DNA in the lab.  Temperatures of a bath are raised and cooled to ge the double strands to separate, primers to be inserted and tac polymerase will extend the stand.  The process is left with short stands of target sequences which have been replicated as they were defined by primers.  This started as a labor intensive process which required hours of manual labor and a large quanitites of enzymes until a bath was invented which allowed for the thermoregulation of the temperature.  

Due to the increased use of capsaicinoid and tolerance of capsicums in the human diet, other health benefits emerged as a consequence.  In Tsuchiya’s study of the effects of capsaicinoids on membrane fluidity, bacterial growth and platelet aggregation were the two subjects (2001).  The lipid form of capsaicinoids were able to interact with the membrane in bacterial cells, inhibiting their growth (Tsuchiya, 2001). This effect on bacteria could result in capsaicinoids being essential in maintaining a healthy gut biome for an individual who was raised in an environment with a high spicy food tolerance.  Gastrointestinal disease has been reported to be decreased with capsaicin consumption (Deng et. al., 2016). In platelets of humans, rabbits, and rats, capsaicinoids were shown to decrease their aggregation (Truchiya, 2001). Capsaicin has already been proven in other studies to decrease cardiovascular disease (Deng et. al., 2016).  The effects of membrane fluidity could be one of the physiological changes within the body which decreased cardiovascular disease. In China, a study was conducted to determine if chili intake and capsaicin had any effect on the obesity of the population (Shi, Riley, Taylor, & Page, 2017). Although this was one of the first conclusive studies done involving obesity, there was conclusive evidence that chili intake had an inverse effect on obesity and might provide a low cost solution to obesity problems in China (Shi, Riley, Taylor, & Page, 2017).  Through the decrease of obesity, there is a multitude of other health complications that can be relieved. One of the flaws with the studies on the health benefits of capsaicinoid consumption is the lack of physiological understanding within the body of how it alters the health of the individual. Until these pathways are fully understood, there will be a slew of health benefits that are not maximized.   

In the study, the limited sample size decreases the accuracy of the study.  Based on the information given, Ulmus americana are the most susceptible to leaf miner infection and have the greatest chance of the leaf miner surviving within the leaf.   From the phylogeny of Ulmus, it is expected that Ulmus americana would have the greatest deviation from the other two species.  While the Ulmus parvifolia and Ulmus carpinifolia had a varying leaf miner presence, they had a relatively similar crude death rate indicating a similarity between the trees which could be explained by their phylogenetic relationship.

Ulmus or elm species and leaf miners.  Leaf miners are relatively harmless to trees but they can have an esthetic effect on trees if they are part of the landscape.  We selected three elm tree where vary along the phylogenetic tree of Elms, the Japanese, smooth and American, with the American being the outlier.  From there two trees from each species had 25 leaves collected from it and the number of leaf mines were counted as well as the number of aborted leaf mines, meaning the leaf miner died.  For our results, we looked at the total number of leaf mines as well as the proportion of those were aborted, the average leaf mine per leaf of each species and the crude death rate per a 1,000 population.  These results showed the highest rate of infestation in the American.  There were similarities in the data of Smooth and Japanese Elm.  Our sample size was very small to have a meaningful statistical analysis done therefore any results of the lab cannot fully support any theory but there are indications that phylogeny can affect the infestation of leaf miners in Elm species as well the their probability of aborting.  For future studies, we would like to expand the sample size of leaves collected as well see if the mortality of leaf miners is seasonal.