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Submitted by cdkelly on Wed, 11/14/2018 - 00:05

It's interesting that the centrosome cycle can simultaneously occur with the other processes of replication. When I think about all of these different processes, it becomes difficult to picture all of these different proteins acting simultaneously with one another to complete massively complex procedures. Also, this is happening across millions of cells at the same time and the overall orchestration is hard to picture.

    These processes must occur in a sequential order. If they somehow began too early or in the wrong order, the consequences within the cell would be devastating. For example, if M-phase began before S-phase was complete, the resulting daughter cells would be deprived of a number of chromosomes and become destined for cell-death. Perhaps overregulation of specific cyclins could lead to something like this.



 

Comments 9

Submitted by cdkelly on Wed, 11/14/2018 - 00:04

It's fascinating that the entire set of 23 chromosome pairs can be copied during S phase. Thinking about all of the components that must be produced to facilitate this replication is complicated. For instance, in order for the DNA to wrap up into chromosomes, the quaternary histone protein and all of its substituents must be synthesized and present. In addition, all of the chromosomal arrangement must be orchestrated by a large number of proteins and chemical interactions must occur. Overall, the entire process is a lot to think about.

    The interactions between CDKs and cyclins are extremely important to the cell cycle and highly organized. Since different phases of the cell cycle are dependent on the levels of cyclins, and consequently CDKs, there must be a large number of them. In addition, they must be produced at critical and specific moments throughout. The amount of involved proteins must be relatively high.

These processes must occur in a sequential order. If they somehow began too early or in the wrong order, the consequences within the cell would be devastating. For example, if M-phase began before S-phase was complete, the resulting daughter cells would be deprived of a number of chromosomes and become destined for cell-death. Perhaps overregulation of specific cyclins could lead to something like this.

 

Week 10 PP

Submitted by cdkelly on Thu, 11/08/2018 - 23:18

Each environment chamber will consist of a styrofoam box with a lid, allowing for access to the enclosures and insulation of temperature. A thermometer will be attached to each environment chamber to monitor temperatures and ensure they are constant. The room temperature chamber will have not have any additional materials. The other two environments will have modifications that allow for the control of temperature above and below room temperature (See Figure 2). For the cool condition, an additional layer of plastic will be placed above a layer of ice. The layer of plastic will have a hole in it to allow for replenishing of ice. Melted ice will drain from a hole at the bottom of the environmental chamber into a receptacle. The ice will ensure that the chamber will maintain a cold temperature for the enclosures within to be subjected to. We will determine the ideal interval for changing the ice to ensure constant temperature prior to beginning the experimental procedure. For the warm condition temperature chamber, a heat lamp fixed above the box will maintain it at 25°C. Like the cool condition, we will determine how far to place the heat lamp from the temperature chamber for a constant temperature prior to the introduction of the enclosures.

 

proposal methods draft redo

Submitted by cdkelly on Thu, 11/08/2018 - 22:48

Each environment chamber will consist of a styrofoam box with a lid allowing for access to the enclosures and insulation of temperature. A thermometer will be attached to each environment chamber to ensure constant temperature. The room temperature chamber will have not have any additional materials. The other two environments will have modifications that allow for the control of temperature above and below room temperature(See Figure 2). For the cool condition, an additional layer of plastic will be placed above a layer of ice. The layer of plastic will have a hole in it to allow for replenishing of ice. Melted ice will drain from a hole at the bottom of the environmental chamber into a receptacle. The ice will ensure that the chamber will maintain a cold temperature for the enclosures within to be subjected to. For the warm condition temperature chamber, a heat lamp fixed above the box will maintain it at 25°C.

To determine the web production in each environment, the plastic cup enclosures will be weighed again once five days elapses. The initial weight will be subtracted from the final weight, which will give us the weight of each spider web produced over the course of the experiment. The difference in weight between the temperature groups will then be compared. Finally, a statistical analysis will be run to see if there is significant correlation between temperature and spider web production.

 

proposal abstract rewrite draft part 2

Submitted by cdkelly on Thu, 11/08/2018 - 21:12

Previous research has found that web production is greatly decreased in the cold, thus we expect the cool condition to have the lowest web mass. This research concerns the effect of temperature on web production and can be related to the global shift in temperature. Global warming is altering the climate and resulting in temperatures that would be considered abnormal in the past. As a result, the behavior and localization of organisms will change. We plan to apply this to cellar spiders to observe how global temperature change may alter their behavior, specifically web production.



 

proposal abstract rewrite draft part 1

Submitted by cdkelly on Thu, 11/08/2018 - 20:47

Our research aims to observe the effect of temperature on the production of cellar-spider webs. We plan to include nine spiders and evenly split them across our three conditions. Each spider will be kept in an enclosure based on a design from previous research and placed into one of the conditions. The enclosures will be weighed before they are put into their respective conditions and again when five days elapse. The three temperature conditions utilized for our experiment will include a cool condition, a room temperature condition, and a warm condition. These conditions will be kept at a constant temperature with the utilization of styrofoam boxes for insulation, a heat lamp for the warm condition, and cycling of ice for the cool condition.

 

homework draft 3

Submitted by cdkelly on Wed, 11/07/2018 - 15:20

After looking over three different posters, I have identified some factors that influence quality; both in positive and negative ways. One of the most important component of a poster in the inclusion of relevant imagery. Many people consider themselves to be visual learners and it is much easier to follow the logic when it is presented in a visual form rather than a large block of text. Going off that, excessive text on a poster makes it much harder for the audience to digest. It can be very difficult to retain information when it is presented only as text. However, text is an important factor in a well-made poster. Of the three posters I viewed, each had more visuals compared to text. These visuals included graphs to display relevant data collected, and images that help to demystify the mechanics of the experiment. But, these posters all had text that would add the necessary details for the researchers to convey their findings. The key thing is to find a good balance of images and text.

comments for this week

Submitted by cdkelly on Sun, 11/04/2018 - 22:40

Considering the sheer quantity of base pairs that need to be copied during replication, its amazing how accurate the cell can be. In addition, the assembly of the chromosomes via histones is incredible because of how much order there is to it and how much information they contain. 

If cells were still able to replicate DNA, there would be too much DNA in the nucleus. This could lead to a number of issues with the cell, including cell death, or possibly even mutations if the overly copied DNA is able to make it into a fully formed cell. Perhaps this is a way that trisomy can occur. 

This mechanism is crucial for the proper function of all cells in the body. If a cell was allowed to enter the M phase without having all of the nucleotides present, there would be missing genes. Therefore, certain proteins would be mutant or absent and the cell would not be able to function properly. This is the case for many genetic disorders and will almost always result in mutant cells. 

Typically in a positive feedback loop the molecule that is upregulated is the one that results in the deactivation of the pathway. For example, in the hypothalamic pituitary axis, the hypothalamus stimulates the release of cortisol from the adrenal cortex, and the levels of cortisol dictate the amount of CRH released by the hypothalamus. CRH is the precursor in the pathway to the release of cortisol, and its levels are reduced when the levels of cortisol are high.  

I did not realize that M-Cdk performed this function in the process of cellular replication. But, It makes a lot of sense. The phosphorylation of the lamin proteins must lead to a conformational shift that causes the depolymerization of the proteins and the degradation of the nuclear envelope. Its fascinating that the CDKs do so much of the work during M-phase. 

I wonder if the delay is a result of the numerous kinases and pathway members required to activate the Cdc20-APC complex. If they are all in the cytosol or freely floating around, it will take time to transmit the signal. Also if there are a large number of members to the pathway, this could increase the amount of time to activate the complex. Furthermore, there could be a limiting reagent involved as the mechanism of delay. 

This is a great example of a positive feedback loop. The Cdc20-APC complex is activated by the M-Cdks which are activated by the M-cyclins. Since the complex is activated by M-Cdks, the deactivation via ubiquitin-mediated proteolysis is done by the complex which then deactivates its activator. This must occur at a certain level of saturation or something like that because the M-cdks need to be active for a portion of the cell cycle. 

 

 

cover letter redo

Submitted by cdkelly on Sun, 11/04/2018 - 22:37

I am contacting you to express my strong interest in joining your laboratory as a graduate student in the Neuroscience and Behavior masters program.Your work with zebra fish and optogenetics is extremely fascinating and cutting edge. Understanding locomotion at the molecular level is something that has massive implications in the clinical world, and I would love to be a part of the team that elucidates it. Your recent work detailing the eight present GABA receptors in the developing central nervous system of zebrafish was a captivating read and the implications of your findings could result in large strides in the field of neuroscience. Of all of the other research opportunities on campus, yours stuck out to me because it’s focus is closely aligned with my own interests. I’ve been a student at this university for three years now, and have always desired to contribute towards some of the fantastic research conducted here, to which I believe yours is at the forefront.     

part of methods

Submitted by cdkelly on Fri, 11/02/2018 - 09:35

The groups of three spiders in their enclosures will then be put in their respective temperature environments. 3 enclosures containing spiders will be placed inside in a room temperature environment. These spiders will be in a styrofoam box kept at 20°C for the duration of the project. 3 other enclosures will be placed in the cooler environment. A layer of ice below the enclosures will maintain a cold temperature for the styrofoam box used for the cool condition. A thin, flat layer of cardboard will separate the enclosures from the ice below them. A hole in this layer of cardboard will serve as a place to periodically add more ice to maintain a constant temperature. The previous ice will melt and drain out the bottom via a small hole. The last 3 enclosures will be heated by a heat lamp at roughly 25°C. Each enclosure housing for the three conditions will be comprised of the same styrofoam box for insulation purposes and fixed with a thermometer to ensure a consistent temperature of the course of the five days. All 9 spiders will be allowed to make webs during this period of time. The spiders will be given food/water and the ice will be switched as needed. After 5 days, each plastic cup will be weighed.

 

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