Drafts

Zugunruhe or migratory restlessness is determined by the circadian clock in response to the annual cycle. In a study of the orientation of Zugunruhe in Common Starlings, the birds were placed in cages in a room where they could see the sun, including its change of position as the day progressed. As long as they could see the sun, they focused their attention towards the northeast, the correct direction for spring migration. On overcast days, however, the starlings showed no directional tendency.

One of the most prominent great thinkers of Ancient Greece, philosopher Aristotle, took a stab at theorizing the nature of gravity in the 4th century B.C. Aristotle believed that different elements gravitated toward different sources based on their own internal nature, rather than an external compelling force. The consensus at that time was that the earth was the center of the universe, supported by the complex diagrams constructed by the Roman Ptolemy which could be used to predict the motion of the visible planets. Thus, Aristotle believed that heavy elements were trying to seek their "correct" place at the center of the universe (the center of the earth).  For this reason rocks would fall to the ground, but lighter elements like steam would rise to their own natural and "correct" place in the sky. This led Aristotle to the conclusion that heavier elements fall faster.

You certainly do not have to be a physicist to know of gravity. Gravity is not some obscure concept mentioned only in the lingo of die-hard astronomy fans, like a quasar or a red giant. Gravity is a concept known by toddlers and astrophysicists alike. From a young age, we learn that when we throw a ball up, it must come back down. We learn that if we slip on the money bars, gravity will bring us hurtling toward the ground. And sadly, we learn that we cannot fly. These lessons are all thanks to gravity. And it doesn’t stop there. We all feel gravity constantly, pulling us to the ground when we are sitting, standing, running, skipping, and jumping. John Mayer even wrote a song about it. We all know of gravity’s existence just like we all know the sky is blue. But while anyone and everyone can recognize that gravity exists, not many people have probably sat down and really asked themselves, from what source does gravity originate? What really IS gravity? And that is where physicists come into play, and the answer is not quite as simple as the concept itself. 

Gobiiformes is an order of fish containing about 210 genera and 1700 species. Gobies are marine fish which occasionally wander into adjacent freshwater areas. Their pelvic and medial fins unite and form a sucker, which they may use to adhere to objects such as plants and rocks. Some sand dwelling gobies have a symbiotic relationship with shrimp. The shrimp will dig a burrow in the soft sand substrate in which the two organisms live. The goby will then alert the shrimp to danger and they will both burrow deeper. There are also reef dwelling gobies. Some species of reef dwelling gobies exhibit a bidirectional sex change. Generally these go from female to male (protogynus), though under lab conditions the opposite direction has been induced by removing the female. When this occurs the largest male will become a female. If two males are ever placed in the same area, one will change to form a matching pair of male and female. Of course this may only work in lab conditions as in the wild, the gobies will likely simply migrate to a new area.

Following up on my work on sensory priming during the past semester and this summer, I will continue running arena trials with a new generation of P. princeps in order to study the behavioral responses of jumping spiders towards visual and acoustic stimuli. My experiments consisted of introducing a jumping spider in an arena so that it walked into a viewing chamber were pictures suddenly appeared in an iPod screen. The pictures were of a wasp (a potential predator), a cricket (a preferred prey), and a beetle (a neutral stimulus). Each spider was shown one image per trial and during the sound trials a speaker played a wasp buzzing sound for 5 seconds every 2 minutes.  Since the trials were run between the end of the Spring semester and this summer, it is possible that the effect of age influenced the spider’s response towards the stimuli, because jumping spiders are very visual and still they showed little response towards the pictures.

There is another form of parthogenesis used by fish in order to reproduce. This form is called hybridogenesis and is also used by monocha-lucida fish. During this process a diploid ML female will produce a haploid M egg. A haploid L sperm will join with the egg, though a female is always produced by this process. However once fully maturing as an adult, the paternal portion of the genes is discarded and the female will once again only produce haploid M eggs, and the cycle repeats.

Other fish use a variety of methods to attract their mates. For instance, some will have physical traits which monopolize on certain behaviors of the other sex. For example, many female fish carry their eggs in their mouths for safety, even before fertilization. Males of this species may produce structures on the ends of their fins which mimic the appearence of eggs. The female will therefore attempt to carry the mimic eggs in its mouth, at which time the male will fertilize the eggs already in the females mouth.

TA – Manisha

Tuesday, 8 AM

Submitted: Oct, 30 2018

Isolation of Trimyristin from Nutmeg

Purpose:

The purpose of this experiment is to obtain a pure organic compound, trimyristin, from the natural source nutmeg. The techniques of extraction, distillation, recrystallization, and chromatography are used to isolate and purify the chemical compounds from the natural sources.

Reaction:

Trimyristin                                Myristic Acid:

MP: 56-57  ℃                                MP: 54.4 ℃

MW: 723.16 g/mol                             MW: 228.37 g/mol

Experimental Procedure:

1.0 g of nutmeg was weighed out on a scale and transferred into a round-bottomed flask using a funnel. 3 mL of tert-butyl methyl ether and 3 boiling chips were also added to the RB flask. A distillations column and air condenser were set up with the black plastic connector to yield the highest results. The flask was lowered into the sand and monitored at a very gentle boil. The mixture was heated for 10 minutes, and then allowed to settle for a few minutes. The color of the mixture changed slightly to a lighter brown. Using a pipet, as much as of the liquid as possible was transferred to a test tube to settle further. The solids were left behind in the RB flask. The liquid was allowed to settle for a few minutes for even further separation of liquid ad small remaining solids. An empty 25 mL flask was pre-weighed. The liquid was transferred via pipet from the test tube to the clean 25 mL Erlenmeyer flask.

Filtration was performed by packing a glass pipet with a plug of cotton; the solution in the 25 mL Erlenmeyer flask was transferred via pipet and filtered through the cotton filter. The solution was allowed to drain completely before a new addition was performed. A pipet bulb was used to help speed up filtration. All of the solution from the Erlenmeyer flask was transferred.

2 mL of fresh tert-butyl methyl ethyl was added to the solid in the RB flaks and warmed very briefly to allow the solids to settle and the liquid was then transferred via pipet into the test tube and allowed to settle further. The liquid was then transferred from the test tube through the cotton pipet filter using a piper and into the same 25 mL Erlenmeyer flask as before.

Gray and white are made up of the same colors. They both use red, green, and blue. The difference between the two is the intensity that each color is added. For example, white is all three colors at their highest intensity (225), while gray is all 3 colors but only at an intensity of 128 each. This experiment is designed to see if the spider will pick the color that is made up of the highest intensity colors, or pick the background that uses less of the colors.

In nature Misumena vatia spends a lot of time on flowers. These flowers provide a background that is complex. This experiment will allow us to test if the spiders prefer a more complex background that has definitions of shapes, like many places in nature, or a simple background. The complex shapes will be abstract in nature, but will not derive in brightness or color from the paired simple background.

Specific Aim 2. Test whether Misumena vatia prefers a cyan or green background. Cyan is created in the RGB model by putting green and blue to their highest intensities, and not adding any red. Green is created by only using green at its highest strength. This experiment will show whether the use of blue has any effect on the spiders background choice.