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intro and the genetic

Submitted by ziweiwang on Thu, 12/05/2019 - 21:30

Retinitis pigmentosa is a degenerative monogenetic disorder of the retina that affects about 1 million people worldwide. People who are affected by the disease slowly lose their vision until they go blind. In retinitis pigmentosa, only the rod cells are affected, creating a unique characteristic at genetic, protein, cell, and tissue level, and have unique challenges in treating the disease. 
The disease usually progresses with prolonged time to adjust to the dark followed by the inability to see in the dark, and restriction in vision. While disease progression differs significantly between different people, most people lose their sight eventually. Because of this the patients often face unique challenges such as being aware that they may have the disease because there are family members that have the disease. Like many people who have a progressive vision illness that ends in blindness, people often have a harder time adjusting to blindness compared to those who were born blind. However, they also tend to be more accepting of the fact that they will be blind compared to those who lose their vision suddenly, with people indicating that things were not as bad as they thought. Other challenges that the people who have this illness must face is the challenge of learning braille, using walking sticks, inability to drive and fear of losing their job or not being hired due to their illness. People who have the blindness describe their sight as though they are walking into a dark room with sunglasses on. The peripheral vision fades first and when the disease advances enough, the vision appears to be narrowed, almost as though looking through a tube. Despite the challenges that the disease poses, it is not fatal, and only vision is lost. 
There are many different modes of inheritance in retinitis pigmentosa, including autosomal dominant, autosomal recessive, x linked and mitochondrial linked. However, RHO  P23H mutation on chromosome 3, also known as RP4 is autosomal dominant and is the most common form of the disease.  The disease was first discovered in the 1970s, with the mutation to be determined in the gene RP1. For the autosomal dominant RP caused by the mutation of P23H rhodopsin gene mutation, the genetic defect was discovered in a large Irish family that had early retinitis pigments for 5 generations in 1989. The paper also tried to establish that the mutation was on chromosome 3. In 1990, a paper established that the P23H mutation in the RHO gene was what caused the disease.

elevator speech

Submitted by ziweiwang on Thu, 12/05/2019 - 21:10

Hi, 
My name is Ziwei, and this is my poster on how the removal of the seed coat affects the seed germination rate. So, what is the seed coat? The seed coat is a protective covering that surrounds the seed and protect the seed from the environment that the adult plant may not be able to survive in. In addition to the protective role that the seed coat plays, the seed coat also plays a role in controlling germination and produces some compound that is beneficial to the seed. This indicates that while it may seem like the seed coat is not doing anything, the seed coat is actually really biologically active. One of the things that have been suggested recently is that the seed coat actually impedes seed growth. Of course, we can all see why that would be important. If the seed starts germinating, there is no going back. you can't turn time back so the seed has to be sure that the ideal condition is met. However, this becomes a problem in agriculture where the ideal environment is provided. the ideal, in this case, would be for the seed to germinate as fast as it can so that the time is not wasted. So, with that idea in mind, this project was done. We removed the seed coat of the seed, and allowed it to germinate, and measured the rate. Our result indicate that the seed germination is somewhat faster in certain types of seeds, however, we were not able to get a definite answer of whether removing the seed coat caused the seed to germinate faster. my personal theory is that because there are so many compounds that seed coat produces, there may be some compounds that are produced by the seed coat that is needed for germination. Our next experiment would be to remove half of the seed coat and see if that would make the seed germinate faster.  

Questions

Submitted by nskinner on Thu, 12/05/2019 - 21:09
 

As resources become more abundant then number of individuals should also increase. As number of individuals increase then the number of species should increase. Due to chance alone, the number of rare species should also increase as well (Gurevitch et al. 2006).Therefore, the more abundant the resources are the more biodiversity is promoted. Disclaimer: It really also depends on what those resources are, what species are present (invasive vs non-invasive) etc. Larger areas essentially means that it is more likely to have more habitats within that larger area. More habitats then in turn means more available habitat to certain species which would promote biodiversityBarriers to dispersal can cause speciation which then promotes biodiversity. Different species live in different habitats. If there is an increase in the number of habitats then there should be an increase in the number of different species occupying those habitats (especially for species that have specialized habitats). Habitat fragmentation decreases biodiversity dramatically. Cutting off gene flow from one fragment to another is not conducive to biodiversity. Being closer to the center of an area means species will be able to interact, find others of the same species, pass on genes with those same species and promote diversity. Being closer to the center also helps the species with edge effects.

introduction

Submitted by ziweiwang on Thu, 12/05/2019 - 20:56

Seed coat, also called a testa, is an outer covering of seed made from integuments that surround the ovule. Seed coats provide protection to the seed, allowing for the seed to survive conditions that they would otherwise not survive. Seed coat also has a role in controlling the growth, development of the embryo and create a compound that helps with the defense of the cell, with a large number of genes that are specifically expressed only in the seed coat, indicating that seed coat serves as more than that of a physical barrier. While the Seed coat serves an important protective role for seeds, there is evidence suggesting that the seed coat may also inhibit germination in some plants. The aim of this study is to see if the removal of the seed coat, which in turn removes all of the compound and protection offered by the seed coat result in faster germination compared to seeds that do not have their seed coat removed in the specific seeds studied.

 

To study how the removal of the seed coat affects germination, the seed coat was removed from 6 species of seeds. To do this, 20 seeds of each species were soaked in water for 1 hour. Then the seeds were divided into two groups ten, one group being the control, the other being the seeds with the seed coat removed. The seed coat was removed using an Exacto knife and slicing the seed coat and then peeling it away. The groups of seed were then each placed onto a petri dish individually labeled with their type and experiment group that contains a wet paper towel. The petri dish was then closed and placed in a dark corner, with the Petri dish covered by the lid. The seeds were checked every 12 hours and the state of the seeds was recorded. The state was defined to be initial germination when there was a sign of germination.

Earth Rotation

Submitted by nskinner on Thu, 12/05/2019 - 20:11

If the Earth changed the direction of its spin the sun would rise in the west and set in the east. The westerlies and easterlies would be blowing in the opposite direction than they are now. Because of this I would expect that the latitudinal distributions of biomes would be similar, but the variation of biomes across continents (east-west) would reverse to some extent. I would expect the mountains to have wetter eastern sides rather than western sides.Perhaps California/Oregon/Washington would be more like temperate deciduous New England and New England would be more temperate rainforest like the redwoods, or mediteranean climate like Yosemite.

Alzheimer's part 2

Submitted by zalam on Thu, 12/05/2019 - 18:20

In terms of data collection, they obtained basal levels of serum cortisol (adrenocortical), dehydroepiandrosterone (DHEA – an earlier form for androgenic and estrogenic steroid formation in tissues), androstenedione, estradiol (estrogen), sex hormone binding globulin, after an overnight fast at 8 in the morning. They did radioimmunoassay using radioactive labels to find the hormones. The main findings were that there was an increased morning cortisol level, higher DHEA and androstenedione in AD patients. Women with AD had a high level of androstenedione and DHEA after BMI and age was considered. There was a strong correlation between androstenedione and DHEA, and cortisol levels, unlike the control group. The most interesting fact is that the levels are this high in the early phase of AD, but it drops in the advanced stage. 

hunger neurons

Submitted by smomalley on Thu, 12/05/2019 - 17:52

In the brain there are multiple different neural pathways that can affect hunger. But there are rare neurons, that when damaged, cause obesity. One such neuron is the MC4R neuron. This neuron signals for satiety. The POMC neuron excits it and tells the brain that it has enough energy, it doesn't have to eat anything else. The AGRP neuron inhibits the MC4R neuron which then signals for hunger. When the MC4R neuron is silences, the body weight phenotype of the mice tested was doubled. There are numerous experimental methods that can be used to silence the neurons such as rAAV virus to insert diolox sites into the genome of the mouse. This would allow you to insert receptors to specific toxins that not all of the cells have, such as diptherioa toxin or tetnis toxin receptors. By doing this, inserting the toxin into that area of the brain would kill only the cells that succesfully recieved the receptor, causing a loss of function. Loss of function experiments are extrelely useful in determining the function of a specific neuron or neural pathway. 

Final PP wooo!

Submitted by kheredia on Thu, 12/05/2019 - 17:23

Continued research on other nocturnal organisms allows more insight into the effects of light pollution on animal behavior, of which continues to invade the lives of night creatures. Scientists could investigate behavioral responses to the effects of artificial light by rearing house crickets from eggs in a controlled environment, and tamper with the way the circadian cycle normally operates. This is a plausible avenue to test if cricket behavior changes when exposed to artificial light, in comparison with our study. This experiment may be better suited for nocturnal organisms, but it could also be conducted with diurnal animals like humans as a measure to gather more and variant data. Better understanding the negatives of artificial light through several contrasting experiments prevents limitation and can help society better understand the effects on a widespread scale. This experiment used a 5 watt lamp, but the results could also connect with bright city lights, technology usage, or even different parts of the world (consequences of jet lag via airplane travel). Studying just one field of animal behavior can answer many questions about the evolutionary mechanisms organisms have developed, and allows an opportunity for scientists to deduct a plethora of new and rich information from behavioral research.

Elevator Pitch

Submitted by smomalley on Thu, 12/05/2019 - 16:59

For this project, we focused on leaf miner damage to different species of Elm trees. We collected 25 leaves from two American Elm, two Japanese Elm, and two Smooth Elm trees. We determined the average number of leaf mines and the percent of aborted leaf mines on each species sampled. We found that the American Elm had the highest average number of leaf mines, with the fewest percent aborted. This could mean that the American Elm is more susceptible to leaf miner damage than the other Elm species sampled.

AQ 12/5 Draft

Submitted by atquang on Thu, 12/05/2019 - 16:47

Over a one week period, the germination rate in a variety of seed species was tested between seeds with and without testa. Particular species of seeds provided evidence of fast germination while others did not. A t-test concludes that there is no significant difference between the germination rates of seeds with or without testa. The germination rate of seeds with testa is equal to the germination rate of seeds without a testa. Uncertainties in our experiment include meeting the optimal environment for each species of seed, as well as the uneven distribution of water to the seeds. Furthermore, a small sample size experiment increases the likelihood of falsely accepting the null hypothesis. Another question our experiment brings up is whether the difference in germination rate between seeds with and without testa is practically significant. Even if the mean germination rate is truly significantly different from seeds without testa, what would industries have to invest to make this happen, and if so, would it be worth it?

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