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The factors we chose to look at were the number of branches on each tree, the number of cut branches, number of tree cavities, distance from human infrastructure and understory diversity. We characterized understory diversity as the number of species, plant or animal living below or on the tree, whether it be fungi, bird nests, or shrubbery.

    What we found was that for on average, trees off campus had a greater number of tree cavities and understory diversity. We also found a correlation between understory diversity and tree cavities, meaning the more tree cavities, the greater the understory diversity.

    What this possibly means is that tree management techniques preventing tree cavities from forming may be decreasing the ecological value of the tree and that maybe in the future, these tree cavities can be allowed by management teams to allow for more species inhabitance.

Hi, for our group project we decided to look at the effects of tree management techniques here at UMass by observing trees both on and off campus. UMass characterizes tree management needs as a strategy for the removal of hazardous conditions and improving the overall wellbeing of the trees on an “as need” basis. By  looking at certain factors we wanted to compare the effects of tree management on tree health and ecological diversity between UMass and the surrounding area of unmanaged trees.

Dr. Chao’s current research involved how the mitochondria gets its shape and factors that influence mitochondrial organization. F1F0 ATP synthase dimers play a pivotal role in the formation of creases and folds in the mitochondria needed for increasing surface area. Dr. Chao showed this by increasing the amount of ATP synthase dimers, which in turn increased the number of creases and organization in the mitochondria observed. Dr. Chao also wanted to understand how dynamic membranes are regulated. This dynamic membrane and formation of cristae is regulated by a number of proteins included Mfn1/2 and OPA1, both of which are in the dynamin family of GTPases. Dr. Chao is currently looking to into the relationship between these proteins and membrane conformation.

Also importantly, they discovered the pre-fusion state envelope protein to be dimeric, while the post-fusion state envelope protein was trimeric. Based on these findings, Dr. Chao and Harrison conducted where they discovered yield of fused membranes increased if they increased the size of the contact patch, and yield decreased as the pH of buffer increased. They also were able to show that the trimerization of envelope proteins is a kinetic bottleneck, limited by the availability of monomers required for fusion. This is important because of its possible application in drug development. The kinetic bottleneck that Chao and Harrison propose means that full saturation would be needed in order to block entry, as opposed to drugs targeting SNAP/SNARE vesicle fusion, which fires and fuses rapidly in the presence of calcium.

Flavivirus is a genus of viruses that includes west Nile virus and cause severe disease such as yellow fever. Flavivirus genomic RNA replication occurs on the rough endoplasmic reticulum, in membranous compartments, and the focus of Dr. Chao and his advisor Dr. Stephen Harrison’s research at Harvard was the fusion of the viral and cellular membranes. Cellular entry by the virus requires this membrane fusion and in order to do so, viral fusion proteins undergo dramatic conformational rearrangements. These proteins, which exist on the surface of the viral envelope, must undergo conformational changes to create a thermodynamically favorable chemical reaction and overcome the energetic barriers to merge the two membranes and create hemisfusion (lost him a bit in the biochemistry on this part).  They discovered that the envelope protein comprised of three main domains, one largely hydrophobic involved in the fusion loop. In its pre-fusion state, the hydrophobic domain is tucked in the protein, however the hydrophobic domain extends into cell membrane then collapses to bring membrane together and create hemifusion and full pore opening.

The research seminar I attended was given by Dr. Luke Chao who is the head of a laboratory at the Department of Molecular Biology at Massachusetts General Hospital and the Department of Genetics at Harvard Medical School.  Dr. Chao received his B.S/M.S in Biochemistry from Brandeis University and received his Ph.D. in Molecular and Cell Biology from UC-Berkeley where he worked with John Kuriyan doing structural studies of calcium/calmodulin-dependent protein kinase II. The majority of Dr. Chao’s seminar discussed his work as a postdoctoral fellow in the laboratory of Stephen Harrison at Harvard investigating the mechanism of flavivirus membrane fusion, however, he also discussed briefly research he is currently conducting regarding the assembly and maintenance of cellular ultrastructures such as organelles.

In this lab a Fischer esterification reaction was performed using the reagents n-propyl alcohol and propionic acid to produce an ester product of n-propyl propionate in the presence of sulfuric acid. The ester product was characterized using odor and IR spectroscopy and was retained with a yield of 68.9%. The odor of the starting reagent propionic acid was described as unpleasant and similar to body odor. The odor of the product was described as fruity and sweet, which is in agreement with the characteristic odor of an ester. This indicates that the reaction went to completion and yielded the desired ester. IR spectroscopy also indicated characteristics of the ester product. Esters are characterized by a sharp, strong peak at 1740 cm^-1, indicated a C=O, and one was seen at 1741 cm^-1. In addition, a sharp, strong peak was described at 2972 cm^-1 , which is typical of an alkyl C-H bond. In addition, the broad peak at 3000 cm^-1 indicated the presence of a carboxylic acid O-H bond and a broad peak with medium to strong intensity at 3300 cm^-1 indicating an alcohol O-H were not seen on IR spectroscopy. The odor and IR spectroscopy indicate successful completion of the esterification reaction to yield n-propyl propionate.

In this lab a Fischer esterification reaction was performed using the reagents n-propyl alcohol and propionic acid to produce an ester product of n-propyl propionate in the presence of sulfuric acid. The ester product was characterized using odor and IR spectroscopy and was retained with a yield of 68.9%. The odor of the starting reagent propionic acid was described as unpleasant and similar to body odor. The odor of the product was described as fruity and sweet, which is in agreement with the characteristic odor of an ester. This indicates that the reaction went to completion and yielded the desired ester. IR spectroscopy also indicated characteristics of the ester product. Esters are characterized by a sharp, strong peak at 1740 cm^-1, indicated a C=O, and one was seen at 1741 cm^-1. In addition, a sharp, strong peak was described at 2972 cm^-1 , which is typical of an alkyl C-H bond.

To a round-bottom flask add n-propyl alcohol (0.82mL, 11mmol) and propionic acid (0.97mL, 13 mmol). Add four drops of concentrated sulfuric acid and mix. Connect the rb-flask to a reflux condenser and heat to a gentle boil. Reflux the solution for 45 minutes. Cool the solution sufficiently. Transfer the cooled contents into a centrifuge tube containing water (1mL) and wash the solution. Perform two subsequent washes with saturated aqueous sodium bicarbonate (1mL) and saturated aqueous sodium chloride (1mL). Pipet organic layer into a vial and add anhydrous CaCl₂ (5 spheres) and swirl. Pipet contents into dry tared capped vial. An IR spectrometry was performed to determine properties of obtained product.

Melting point of the once recrystallized product was determined to be 53-55^oC. The melting point of the twice recrystallized product was determined to be 54^oC. In literature, the melting point of trimyristin was 57^oC. The narrowing melting point range after each recrystallization indicated a relatively pure product formed from recrystallization. The slightly lower melting point obtained versus in literature indicates some soluble impurities present. The product of the hydrolysis and acidification of trimyristin was determined to be myristic acid using melting point analysis. Melting point of the myristic acid was determined to be 51-52^oC and the literature value of expected melting point of myristic acid was 54^oC. The slightly lower melting point obtained as well as the narrow melting point range indicate subtle impurities.