ncarbone's blog

The debate about genome editing arises as the ethical issues are being exposed towards humans. Genome editing is a form of genetic engineering where DNA can be altered by insertion, deletion, or replacement to modify a targeting gene. One of the most common methods utilized for this desired effect is a CRISPR-Cas9 plasmid (Petherick 2015). This method is achieved by inserting the Cas9 and the CRISPR RNA (crRNA) to the target site on the genome, where Cas9 cuts the current DNA so crRNA can begin to create DNA in the target site. The created DNA leads to alterations in the genome, including insertions, deletions, and homologous recombinations (Zhao et al. 2014). This new tool has led researchers to believe that gene editing could potentially solve health problems linked to genes. Moreover, advancements in gene sequencing allow geneticists to accurately indicate which genes are causing gene-related health issues. However, insufficient studies prove that the mechanics of gene editing are safe and effective. Additionally, countries are banning research on gene editing for not only safety and ethical reasons, but because of potential gene edits that would be passed down to future generations. Regulations are currently being implemented for studies, and guidelines for human use regarding safety.

Genome editing has potential to eliminate or minimize deadly diseases in the human genome. It has been popularly used among agricultural scientists, for genetically-modified organisms, and those specialized in infectious diseases and epigenetics (Petherick 2015). Genome editing has been progressively trialed for treating single-gene diseases, such as cystic fibrosis and sickle cell disease (Hsu et al. 2015). Germline editing could knock out a disease not only in the embryo in which it is being performed on, but also eliminate the disease from future generations.  Human diseases such as HIV could potentially be eliminated from the human genome. Gene editing in conjunction with stem cells might make it possible to generate gametes for reproductive purposes and correct errors in their genome. This would minimize the need for oocyte donation (Sugarman 2015). Also the use of CRISPR/Cas9 is an efficient and inexpensive method for gene editing.

Somatic cell gene editing modifies a subjects DNA in order to try and treat a disease caused by a genetic mutation in a specific type of cell. Only the targeted cell type will be affected through somatic gene editing. One way to perform this is the use of CRISPR techniques on blood stem cells to try and fix the genetic mutation. This will change the subject’s blood cells, but will not have any impact on their sperm or eggs. This means that the edited gene will not be passed down to future generations.

Based upon Table 1 the influence of grazing on aboveground NPP in a year with average rainfall has a net negative effect compared to NPP without grazing especially in low nutrient areas. There was not much of a difference in high nutrient areas when comparing grazing and no grazing, but there is a significant difference in low nutrient areas. For Table 2 the influence of grazing on NPP has a noticeable decrease in effect for both low and high nutrient fertility areas. The net primary production is clearly positively impacted by areas without grazing. Table 3 shows a negative influence on low nutrient areas where there is grazing. However, there is a positive effect on NPP when there is grazing in high nutrient areas. Overall when comparing the three tables, grazing tends to have a net negative effect on NPP. Even when grazing produces a high NPP value no grazing usually still produces a relatively high NPP. As rainfall increases the NPP tends to increase for the most part across all scenarios. However, when there is less rainfall grazing seems to have more of a negative effect on NPP. The one outlier is when there is low rainfall and grazing in high nutrient sites there is a surprisingly high NPP value.

Based upon figure 1 the effect of Ulva on Gigartina is a positive effect following the facilitation model. A facilitation model means that early colonists modify the environment so that it is more suitable for late successors and less suitable for other early successors. The Gigartina is a late species and when the Ulva is present then the number of Gigartina increases over time. When Ulva is removed the Gigartina levels are consistently low throughout both years. The pattern of mortality for fir and aspen changes when the aspen plots are thinned. When the aspen plots are thinned the fir mortality increases but the aspen mortality stays the same. This could be due to the fact that the fir are more susceptible to fire in the absence of aspen. The likely mechanism controlling these interactions is a tolerance model. In a tolerance model the earlier successors modify the environment so that is has a small effect on the later successional species. The later successor then takes over the colony and can eliminate the earlier species. In figure 2 Aspen is the earlier successor but over time the fir can still increase in density despite the presence of the aspen. However, as the Fir continues to grow the density of the aspen starts to decrease.  

I would expect to find this biome on the more northern edge of the temperate deciduous forest range due to the cold temperatures year-round. Somewhere around 50 degrees north. Plant forms that I would expect time find include oak trees, maple trees, some shrubs, and canopy trees. These trees are adapted to freezing weather due to their deciduous leaves. These leaves do not have to photosynthesize as much as other leaves so there is less activity on them.

I predict that the second biome is a temperate deciduous forest. Temperate deciduous forests have extended periods of freezing and in the graph of this biome there are 4 months with an average temperature below 0 degrees Celsius. Also, the pattern and relationship between temperature and precipitation is not only consistent but as temperature increases, so does precipitation. The highest temperatures and the highest precipitation amounts are observed during the months of June-August. Also, temperate deciduous forests typically have somewhere between 500-2,500mm of rainfall in a year and this specific biome received 1,562mm in a year.

Some general plant forms that I would expect to find in this biome would include an open canopy of short trees, evergreen trees and shrubs, and more specifically plants with sclerophyllous leaves. These leaves help the plants continue to photosynthesize during the dry drought season of the summer. Also, fires are typically common in temperate shrubland/woodland biomes, so the plants would most likely be adapted for dry soils and fires during the drought season. However, due to this biome having slightly more precipitation than a typical temperate shrubland/woodland there might be slightly more vegetation. Lastly, I would expect to find this biome somewhere around 40-50 degrees N/S due to the climate patterns.

2.08 grams of cyclohexanol and 0.5 mL of 85% phosphoric acid were added to a micro round bottom flask. The solution was heated and boiled in a fractional distillation apparatus until about 10% volume of the solution remained. The distillation started at a temperature of approximately 70°C and reached a temperature of approximately 72°C at the completion of the distillation. After the distillation the solution of water and cyclohexene distillate was transferred into a reaction tube. Another 1mL of water was added to the tube and backwashed. The lower layer of the tube was removed into a waste beaker. 1 mL of sodium hydroxide was then used to backwash the organic layer. The bottom layer was removed to waste and then 1 mL of brine was used to backwash the organic layer again. The bottom layer was removed to waste. The solution was then dried with CaCl₂ and transferred into a tared vial to yield the cyclohexene product (0.729 grams, 42.63% yield). The product was verified by performing a test by adding a solution of 3% bromine in dichloromethane (3 drops) into 0.5 mL of the cyclohexene product and 0.5 mL of cyclohexane. Color changes and precipitate formations were noted. Then another test was performed by adding 3 drops of potassium permanganate to 0.3 ml of cyclohexene and 0.3 mL of cyclohexane. Color changes and formation of precipitates were noted again. Finally, GC and IR tests were performed to assess the purity of the product.

During this experiment the starting materials, cyclohexanol and 85% phosphoric acid were reacted to produce a cyclohexene product. The product was obtained at a 42.63% yield. The product was then identified using chemical tests and GC and IR tests. The first chemical test performed was adding bromine in dichloromethane to a sample of cyclohexane. The color of the sample changed from a red-brown to a clear color indicating that the sample was cyclohexene. The second chemical test performed was adding potassium permanganate to a sample of cyclohexene. Again, the color changed from purple to clear with a brown precipitate on the bottom once more indicating that the sample was in fact cyclohexene. Examining the IR test, it is evident that cyclohexene is present due to the peaks at the frequency range of 2900-3022. The typical range of an alkene is between 3000-3100. The GC test showed that the final product was not 100% pure. There were two peaks on the GC test one of which had an are percentage of 99.25%. This means that there may have been a small amount of impurities in the sample such as water.