Blogs

The experiment that we did this week was too find the India ink consumption rate of tetrahymena over certain time periods. The way we did was to add Glutaraldehyde to the tetrahymena to stop them from moving. Then we added India ink to the tetrahymena and let them sit for certain intervals of time. After the period was up we looked at the tetrahymena under the microscope, and counted the number of vacuoles in each cell containing ink. We counted ten different cells for each time. After finding all this we found the mean and the standard deviation for all the different time periods. We found the standard deviation by finding the mean of all the vacuoles at each time

This creates a false image of which people will try to attain. People will try to look like this because it is shown as attractive, and everyone wants to be thought of as attractive. The result of people even attempting to look like this will create nothing but disappointment because of how unobtainable it really is. People normally have many things that occupy their time, such as jobs, school, family and other important responsibilities. This means that there really is not time in the day to try and work out and plan out diets as to look like this. 

A B. distachyon leaf was frozen using liquid nitrogen and then ground up.  DNA extraction buffer (DEB) was added.  DEB contains 1% sodium dodecyl sulfate (SDS), a detergent which binds and solubilizes lipids found in the cell membrane.  DEB also contains 25 mM ethylene diamine tetra-acetic acid (EDTA), which binds metal ions that enzymes, such as DNases, require to function.  Potassium acetate (KOAc) was used to precipitate proteins and carbohydrates while nucleic acids remained soluble.  100% isopropanol was used to precipitate the nucleic acids from the salty solution.  The pellet was rinsed with 70% ethanol to remove sodium.  The pellet was resuspended and stored in 50 mL T₁₀E₁ buffer, which contains 10 mM Tris and 1 mM EDTA.

DNA extraction is only the first step in exploring the genes that exist in the genome. When we finally have the genomic DNA of an organism, we need to know how much DNA we have and how pure the DNA is. We'll need to evaluate the quality and quantity of our DNA. The quality of our DNA can be examined by using Nanodrop. This enables us to see how purity (A260/280) and concentration of our DNA. This knowledge will influence how DNA we use in subsequent processes like PCR, in-vitro transcription and so on. The ideal purity of DNA is 1.8. Newly extracted DNA is likely to have its A260/280 exceed 1.8, indicating the presence of impurities like RNA. We can visualize our DNA by using gel electrophoresis. We pour agarose gel, containing ethidium bromide, into a rig with a comb. We add specific volumes of our samples and a ladder to the wells formed in the gel by the comb. The ladder is needed as a yardstick against which we can deduce the approximate length of strands. Seeing as DNA is negative, it runs towards the positive end of the gel and add varying speeds depending on the size of a strand. The final gel can be viewed under UV light to visualize the distinct bands. 

CDK 4/6, when bound to cyclin D, hyperphosphorylates the Rb protein to proceed through the cell cycle past the G1 checkpoint and eventually divide. Therefore, by inhibiting this CDK 4/6 complex, cell division is halted as the cell cannot proceed past this checkpoint. As of today, there are three US FDA approved CDK 4/6 inhibitors on the market: ribociclib (Kisqali), palbociclib (Ibrance), and abemaciclib (Verzenio). These inhibitors are effective for individuals with metastatic hormone receptor-positive, HER2-negative breast cancer (2). Both ribociclib and palbociclib are approved to be taken in combination therapy with letrozole (Femara), an aromatase inhibitor (4). Aromatase inhibitors lower the estrogen production at the site of the cancer, which can be helpful in hormone-sensitive breast cancers in postmenopausal women as they respond to estrogen (1).

This article is more of review and takes examples of previous studies and compiles them all into one document. The methods used to detect neuropathy are not explicitly states therefore it is difficult to determine how they decided what was minor and severe neuropathy. I think that using the Toronto clinical scoring system (TCSS) would be the best choice in determining minor or full onset neuropathy. With this system a score of 6-8 points would be considered mild neuropathy while a score of 12-19 would be considered severe neuropathy. This system also uses three different parts in order to come up with a neuropathy score, The three parts include a symptom score, a reflex score, and a sensory test score. Another scoring system that I think would be adequate would be the clinical neurological examination system (CNE). This system also classifies neuropathy in four different stages, none, mild, moderate, and severe.

The rate of photosynthesis can be limited by light levels and carbon uptake. However, resource availability and competition are also limiting to tree growth. Trees need water and minerals in order to grow. Specifically, trees need large amounts of nitrogen and phosphorus. However, these nutrients are often limiting because they are needed in greater quantities than available in soil. Nitrogen is needed for growth, reproduction, and photosynthesis. It exists in organic and inorganic forms in soil, however trees can only uptake two major inorganic forms, nitrate and ammonium. Therefore, trees have to rely on nitrogen-fixing organisms in order to obtain the amounts of nitrogen necessary for survival. Likewise, phosphorus is present in soil in organic and inorganic forms, but it is not always available for the tree to uptake. Phosphorus binds tightlyto particles in the soil that make it hard for the trees to access. Trees also have to rely on other organisms in order to receive most of their phosphorus. They can get it from microbial activity or decomposition of microbes or other organisms. Additionally, the soil composition effects the amount of nutrients and water a tree can access.  Large soil particles hold a greater amount of water than coarse soils. Since nitrogen is taken up by roots mainly through bulk transportation of water through the xylem, soil particle size can limit the amount of water and minerals taken up by trees. Another way soil can play a role in nutrient availability is through cation exchange capacity. A soil that has a large cation exchange capacity is able to attract and hold ammonium, reducing the amount of nitrogen leached from the soil. 

On my mother’s side my grandfather was Palestinian and my grandmother was American-born to parents of German descent who likely had Danish origins further down the line. Going back about 500 years or more, the Palestinian side has some possible connections to Syria and/or Yemen. There is some speculation that there may also be some Russian or Greek heritage, based on some Greek Orthodox backgrounds and the fact that my mother’s grandmother had a Greek name. A significant portion of my genetic ancestry is Mediterranean/ Middle Eastern, and I think my phenotypes reflect this. I inherited my father’s dark brown eyes, thick eyebrows, and light olive skin that rarely burns and tans easily; all very common traits in that region of the world. From my mother’s side I got my round face and my wavy/curly hair. My hair color is an medium/dark brown, an intermediate between my father’s black hair and my mother’s light brown hair. 

The debate about genome editing arises as the ethical issues are being exposed towards humans. Genome editing is a kind of genetic engineering where DNA can be altered by insertion, deletion, or replacement to modify a targeting gene. CRISPR-Cas 9 is an enzyme that performs the process by cutting out DNA at a specific sequence and makes the ‘edit’. This new tool had 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. Countries are also 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 placed for studies and guidelines for human use regarding safety.

Predators are an important part of a healthy ecosystem. By controlling the size of prey populations, predators help slow down the spread of disease. Predators catch healthy prey when they can, but catching sick or injured animals helps in natural selection and the establishment of healthier prey populations as the fittest animals are left to survive and reproduce. Predators such as the wolves from the Yellowstone were essential for all other life to function together and grow. The presence of the wolves decreased the deer population which in turn allowed more vegetation and forests to grow back and prosper, which ultimately lead to more diversity and stabilized the rivers. Maasailand Preservation Trust (MPT) is an example of one predator compensation programme working in response to the threat of local lion extinction in African plains. It not only aims to prevent lion extinction but also provides coverage for other persecuted species, such as hyena, cheetah, leopard, wild dog and jackal. In areas such as Maasailand these animals are under threat from livestock owners who see them as a danger to their livestock and kill them in trade for livestock losses. From this project, within a decade people who were once killing these predators by the hundreds are now working to protect them and reduce the killing of lions.