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Methods project reflection

Submitted by danielcosta on Wed, 12/13/2017 - 15:53

Through the Methods Project, I was able to learn how to decipher my own observations from the inferences that are made because of these observations coordinated with previous knowledge. Previously, I did not understand the concept that inferences were made through observations. I never put much thought into the topic, and mistakenly thought that observations made were one in the same as the inferences derived from observations. During the Methods project for our Results section, we had to exclusively point out the different observations that were made looking from our original figure to the replicate figure. It was only in the discussion section that I was to infer what exactly may have been different during the timing of the photos taken for the two figures. These inferences I made for my discussion section was a direct product of the differences I observed for my results section. This exercise was able to teach me how to grasp the concept of observations and inferences being different from one another.


Submitted by danielcosta on Wed, 12/13/2017 - 14:44

ACD2 is a protein in cells that is used to regulate programmed cell death (PCD) in plants. ACD2 is activated when plant cells are under an environmental stress and are triggered to kill off certain cells. These cells may include those that are infected with a pathogen, for example. In the absence of ACD2, the plant would be molecularly triggered to kill off those cells and other cells that the pathogen may have spread to. This would lead to the plant rapidly killing off numerous cells and it would start to phenotypically die, becoming yellow and wilted. ACD2 works as a regulator to slow down the process of PCD and only kill of those cells that are absolutely necessary in order to ensure the plants survival and acclimation. ACD2 is triggered by the breakdown of chlorophyll and works to eliminate the free radicals generated by the active light-dependant processes that chlorophyll breakdown product produces. 


Submitted by danielcosta on Tue, 12/12/2017 - 17:59

The impact that a snowstorm has on the hydrologic system of the area in which it falls is much larger than that of rain. This is to say that 20mm of snow will input water into the hydrologic system over a longer period of time than 20mm of rain will. It is a pretty intuitive concept. One hard rainstorm that produces 20mm of precipitate will make its way down to the soil and be soaked into the hydrologic system in the matter of two, maybe three days. When you think about a snowstorm that produces 20mm of precipitate, the snow stays on the ground for a longer peiod of time and is melted by the heat of the sun. The snow melts a little each day, soaking the soil over a loger period of time.

elevator speech

Submitted by danielcosta on Tue, 12/12/2017 - 12:00

An organism’s ability to acclimate to its environment is a key factor in ensuring its survival. Especially in today’s day and age with the ever-changing effects that global temperature increase has on environments and the organisms that live there, it is important to be able to acclimate quickly. Planarians are known to be photophobic organisms and express discomfort when under intense light. In our experiment, we tested the rate of acclimation of planarians to different intensities of light. We accomplished this by placing a food source, liver, in one half of a petri dish with light shined right above it, illuminating only the area near the liver. We placed the planarians near the liver and recorded their behaviors, running 3 separate trials for a duration of 5, 10, and 15 minutes. We used 3 different lumens of light intensity and ran a control group with no light. We hypothesized that the higher the intensities of light would cause the planarians to exhibit photophobic responses at a faster rate and that it would take them more time to acclimate to the light, if they acclimated at all. 

Atlantic Salmon

Submitted by danielcosta on Fri, 12/08/2017 - 18:35

The Atlantic Salmon population in the river systems of New England, especially Maine, have declined rapidly since the 1960's. This rapid decline is due in large part to the effects that human urbanization has had on these river systems. Disturbances to the environment, like clear cutting forest patches and the construction of dams, have degraded the water quality of these rivers tremendously. Unloading of logs and sediments into the river made the chemistry balance of the rivers unfit for the salmon. Construction of dams has put physical barriers in the path of salmon migration to and from the rivers to the sea. These factors added in with the exploition of salmon for commercial use has greatly damaged the salmon population, possibly beyond repair. 

Muscles of a Spiny Dogfish

Submitted by danielcosta on Tue, 12/05/2017 - 19:58

There are several important muscles in a spiny dogfish that all play a role in making its jaw raise, or open, and close. These muscles include: adductor mandibulae, levator palatoquadrati, intermandibularis, levator hyomandibulae, coracoarcuals, coracomandibularis, and coracohyoidus. While the adductor mandibulae and the intermandibularis assist in closing the jaw, the levator palatoquadrati and levator hyomandibulae assist in raising the jaw. The coraco- muscle groups are all involved with the opening of the mouth. The levator muscle groups work together to raise the top jaw and gape the mouth open while the coraco- muscle group work together to open and widen the lower jaw. It is an intricate and amazing system when all seven of these muscles work in unison every time a spiny dogfish chews on its prey. 

Water quality

Submitted by danielcosta on Mon, 12/04/2017 - 23:05

Forested areas and high densities of vegetative biomass near watershed outlets are essential in order for water quality to remain high. Buffer zones surrounding headwaters and streams play a major role in reducing the amount of sediment and nutrients that get washed into these waters during large storms that produce a great amount of overland flow. The biomass in these buffer zones take in or stop this "waste" from getting to these waters through various processes. A few of these processes include nitrogen uptake from trees or the filtering of sediments through grasses. Trees uptake large amounts of nitrogen and store it in order to accumulate more biomass while grasses act as a filter that stops the flow of larle, loose sand and clay particles that would otherwise find their way to the streams. While just these two processes alone greatly improve water quality, there are several more processes these buffer zones put into action that improve it even more.


Submitted by danielcosta on Fri, 11/10/2017 - 02:02

Epigenetics is the study of changes in gene function that are not caused by changes in the DNA sequence. This is a quite interesting and rapidly growing field of genetics. Epigenetics describes phenomena in which genetically identical cells may express their genomes differently, which will cause phenotypic, or observable, differences. The driving forces of epigenetic differences are mainly environmental effects. The two main components of epigenetic code are DNA methylation and histone modification. DNA methylation is when methyl marks are added to certain bases of the DNA. This can repress gene activity of the methylated DNA. Histone modification is the process by which a combination of different molecules may attach to the end of a histone's "tails". This may alter the gene activity of the entire strand of DNA wrapped around the histone. 

Open Channel Waterflow

Submitted by danielcosta on Wed, 11/08/2017 - 22:15

There are three categories used to broadly define the energy status of flowing water in an open channel system. The slowest flow is defined as subcritical flow. This energy status is represented by slow moving water that is moving laminarly, or in parallel in relation to the water around it. The fastest flow is defined as supercritical flow. Water in this category is moving in a turbulent manner; parcels of water are mixing with each other and there is no uniform direction of waterflow. The transition zone, the zone of energy where subcritical flow transitions to supercritical flow, is defined as the critical zone. In this zone, water gains momentum and speed and begins the process of becoming less uniform. A physical example of the three categories of flow is well represented by a waterfall. At the top of the fall, before the drop, there is the subcritical flow, in which water is moving relatively uniform in a laminar manner. Here, the water seems to be moving relatively calmly, as gravity is the only driving force of flow. Once water reaches the edge of the drop, it begins its ascend to the bed below it and becomes slightly turbulent. After the water reaches the bedrock below, there is no uniform flow at all, as the water is now fully turbulent. Flow here is dominated by inertia and moves in any which direction with brute force. 

Cell Death

Submitted by danielcosta on Mon, 11/06/2017 - 22:53

Cell death is an important process in plants. It can be brought about for various reasons including pathogen-resistance and plant development. There are three types of cell death in plants. There is programmed cell death which includes apoptosis and autophagy, and there is nonprogrammed cell death which includes necrosis. Programmed cell death is an active process that is utilized to rid the plant of damaged or unneeded cells. During apoptosis, chromatin condensation and DNA fragmentation occur and cytoplasmic components enter the vacuole, where lytic enzymes breakdown the now useless material. During autophagy, the vacuole of the plant cell is ruptured and the lytic enzymes breakdown the organelles and cytoplasm of the cell. We have not learned about unprogrammed cell death yet and so I cannot accurately describe this to you at this time. 


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