methods prompt

Submitted by kruzzoli on Tue, 12/04/2018 - 16:11

We watched 5 minutes of videos of polar bears, Ursus maritimus, from the Macaulay Library database to observe behaviors and we identified certain behaviors that the polar bears did. We identified a list of behaviors and divided this list into four categories based on how much energy each behavior takes. The four levels of energy were minimal energy, low energy, mid energy, and high energy. We identified minimal energy behaviors as lying down and standing still. Low energy behaviors were walking around with the nose up or nose down. We identified mid energy behaviors as walking quickly and swimming. Running, digging, diving, and shaking were high energy behaviors. We watched 30 additional minutes of videos of polar bears from the Macaulay Library database and using Jwatcher, recorded how much time each behavior occurred. We took a screenshot of each behavior and put the images into a table based on the energy level and added a description of each behavior. Each behavior in the table appears chronologically. To determine how much energy the polar bears have, we identified the location and season of when the videos were taken and we identified the food source of these particular polar bears.


Fellowship Proposal Intro -PP

Submitted by mmaliha on Tue, 12/04/2018 - 15:11

When one thinks of cancer research, one visualizes rows of petri dish, isolated cell cultures (of either humans or mice) and scientists hunched over benchtops pipetting chemicals. When I heard of my assignment for the LEE-SIP internship, I imagined the same. So, I was really surprised to learn that I would be working with fruit flies and mostly in-vivo. This past summer has taught me that the learning curve of doing research in a lab is exponential and continuous. I have already learned so much, yet there remains so much more to investigate. I have looked into the role of ABC transporters in effluxing chemotherapeutics and facilitating drug resistance. And, I want to understand more about the various regulatory defense mechanisms of our cells and their interaction with toxins. Not only does this research tie in with my current interest in genetics and cell and molecular biology, it also accommodates my future aspirations as an MDPhD candidate. The experiments I am conducting now has valuable implications for future usage of chemotherapeutics and the interaction of cell and molecular biology with environmental science and toxicology.  

Fellowship Proposal Intro

Submitted by mmaliha on Tue, 12/04/2018 - 15:02

I will not lie. Once I had known about my assignment for LEE-SIP internship, I was most excited at the prospect of cancer research. I expected working with petri dishes and isolated cell cultures, either human’s or mice’s. So, I was really surprised to learn that I would be working with fruit flies and mostly in-vivo. It seems as though the learning curve from working in the lab is exponential and continuous I have already learned so much, yet there is so much to run. I want to know the toxicology impacts. Not only does this research ties in with my current interest on genetics and cell and molecular biology, rather it facilitates my future interest and path as an MDPhD candidate. Experiments like what I am conducting now will dictate possible drug uses for chemotherapy patients. Or, at the very least, it will have impact on environmental science and toxicology.

more lab stuff

Submitted by eehardy on Tue, 12/04/2018 - 15:02

2-naphthol was reacted with sodium hydroxide and n-butyl iodide via an SN2 reaction and butyl naphthyl ether was obtained in 5% yield. The product yield was very low due to incorrect use of the suction filtration machine by the student. The product was identified as butyl naphthyl ether via TLC analysis with correct data from the student’s partner, as well as from using the melting point of the small amount of product that did form. The first plate did not have applicable data because the amount of product formed was too small to make a significant difference between A, B, and C. The spots were all almost entirely equivalent to the A spot (the 2-naphthol solution) because the amount of product (C ) was so low, thus making the C spot ineffective and the B spot essentially just the same as the A spot. However, the plates of the student’s partner, which had the better ratios of hexane to EtOAc sufficed for the date for the rest of the Rf values. On plate 3, substance C travelled farther than substance A, which tells that the final product of the reaction is much less polar than the starting material. This makes sense in accordance with the reaction scheme because 2-naphthol is more polar than butyl naphthyl ether. Of the three solutions used, the best separation of substances was obtained with the solution ratio 60:40 hexanes:EtOAc. The solution with 25:75 hexanes:EtOAc was too polar to get a sufficient separation and the solution with 75:25 hexanes:EtOAc was not polar enough to get a sufficient separation of the substances present. By adding more EtOAc, the solution became more polar so that both the starting material and product had sufficient separation. The hexane composition of this solution agrees with the assumption that the product was less polar than 2-naphthol because butyl naphthyl ether is less polar than 2-naphthol The identity of the product was shown by the sample’s melting point of 33 °C, which fits with butyl naphthyl ethers melting point  of 33-35 °C.



Isopentyl Propionate

Submitted by mmaliha on Tue, 12/04/2018 - 15:00

11 mmol or 1.58 grams of isopentyl propionate was expected to be recovered from the acid-catalyzed reaction of 11 mmol of 3-methyl-1-butanol with 13 mmol of propionic acid. However, only 0.292 g of final ester product resulted in a low recovery rate: 18.5%. Low percent recovery could have been due to reflux reaction not going to completion (substantial amounts of unreacted alcohol and carboxylic acid remained in the rb flask after reflux) or loss of organic product during reaction work-up.

Isopentyl propionate had a sugary banana odor, compared to 3-methyl-1-butanol’s bittersweet licorice smell and propionic acid’s bitter vinegar smell. The odor test confirms formation of isopentyl propionate as it is known for its usage as a flavor extract: mainly fruity, ripe, banana smell.

The IR spectroscopy of isopentyl propionate also confirms the formation of an ester product, since it displays the characteristic carbonyl peak specific to esters: sharp, strong, 1740/cm. However, there is some unreacted alcohol product left in the final sample, as evidenced by the broad peak of medium intensity at 3300/cm.

Obesity might be linked to Cancer PP

Submitted by yurigarcia on Tue, 12/04/2018 - 15:00

The presence of fat makes the immune surveillance systems fail, a group of cells whose function is to destroy cancer cells. Research, led by Trinity College in Dublin has discovered new links between obesity and cancer, which explain why the body's immune systems fail to fight cancer cells when there is an excess of fat. The study, published in the journal Nature Immunology, analyzes the causes why the presence of fat makes fail the immune surveillance systems, which are formed by Natural killer, a type of natural killer cells whose function is to destroy cancer cells.

People with excess weight are more likely to suffer from type 2 diabetes, cardiovascular diseases and a wide range of infections, in addition to the fact that up to 50% of certain cancers are attributed to this pathology. Of course, there should be more ways to understand the ways in which obesity causes cancer and leads to other diseases and, therefore, to develop new strategies to prevent its progression.

Esterification and IR (Part 2)

Submitted by mmaliha on Tue, 12/04/2018 - 14:59

The cooled contents of the flask were transferred to a centrifuge tube containing water (3 mL). The layers were mixed thoroughly, and the aqueous layer was removed. Sat. aq. sodium bicarbonate was added (1 mL) and the layers were mixed again. The aqueous layer was removed, and the process was repeated once more. Sat. aq. Sodium chloride (1 mL) was added to the ester and the layers were mixed. The lower aqueous layer was removed and added to the waste beaker. The organic layer was transferred to a clean vial and 5 spheres of anhydrous CaCl2 were added as a drying agent. The spheres of CaCl2 instantly fell apart and mixed with the liquid which indicated the presence of excess water in the ester product. Since product could not be recovered, experiment was halted and another student’s data on isopentyl propionate was used for the ‘results’ and ‘discussion’ portion of the lab report.

Esterification and IR

Submitted by mmaliha on Tue, 12/04/2018 - 14:58

The n-propanol (0.82 mL, 11 mmol), propionic acid (0.97 mL, 13 mmol), and concentrated sulfuric acid (4 drops) were added to a 5 mL round-bottomed flask. Contents were mixed thoroughly, and a few boiling chips were added. A distillation apparatus was set up at a 45° angle and the rb flask was heated to a gentle boil on the hot plate. The heating was adjusted so that vapors condensed about ⅓ of the way up the reflux condenser, well above the side arm. After reaction refluxed for 15 minutes, two phases of liquid collected in the side arm, an upper organic phase and a lower water phase. At this point, the apparatus was raised from the heat and tipped so that most of the upper phase in the side arm dripped back into the reaction flask. This process was repeated after 15 minutes. The reaction mixture was allowed to reflux for another 15 minutes (for a total runtime of 45 minutes). Afterwards, the apparatus was allowed to cool for 15 minutes and the entire contents of the side arm were emptied into the flask.


Submitted by kruzzoli on Tue, 12/04/2018 - 14:22
  • Six spiders of the Pholcus-pholcidae species were collected and placed into  six separate clear containers. The weight of each spider was recorded using an analytical scale. Each spider was placed on a plate, weighed, and then we subtracted the weight of the plate from the weight of the plate with the spider to get the weight of each spider.

  • The spiders were given one mosquito at the beginning of the trial after being weighed and allowed to spin their web for three days at a constant environment of 20 degrees celsius.

  • A strand of silk was removed from three of the spiders containers because not all 6 spiders produced enough silk to be measured. Using tweezers, the silk from each sample was placed onto a microscope slide and a cover was placed on top.

  • We used a Nikon Inverted Microscope Eclipse microscope to take pictures of the samples. For each sample, we took two images of the web from different areas of the sample.

  • We used Fiji to analyze the images of the webs. For each image, there was .108 microns per pixel. We used this ratio to determine the ratio to measure silk thickness. The known distance for each thickness was determined using Fiji to draw a line from one end of the silk to the other, and the number of pixels was divided by .108 to give the length of the silk in micrometers.

One thin strand of silk and one thick strand of silk was measured in each image. We measured the thickness of five different points on a 28 μm width of the silk. The average of these five measurements was calculated to determine the average thickness of the silk.


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