msalvucci's blog

An inference is an educated guess as to why something is the way it is. In most cases, this inference stems from a previous observation. These observations and inferences are made every day whether we are aware of it or not. Today I observed that my friend walking out of an exam had a distressed look on her face. From that observation, I inferred that the test was difficult. I did not know for a fact that the exam was difficult, however, I understood from prior knowledge that facial expressions can indicate how a person feels about an exam. In this case, my inference was correct; I confirmed my inference by asking how my friend felt about the exam. Overall, the observation that my friend was distressed and my knowledge that she had just finished an exam led me to infer that the exam was difficult. 

In the computer lab, both pictures were exported to Microsoft Word (version 15.26). Both pictures were placed side by side; the one on the left was the picture of the Lewis Hall main entrance and the picture of the right was the picture of the zoomed-in spider web. Following the placement of these picture, a screenshot of the ‘OpenMaps’ aerial view map of UMass Campus was taken; this screenshot was zoomed in so that North Pleasant Street, Thatcher Road, and all of the residential halls in between these two streets were present in the screenshot. Lewis Hall was present in the right, upper corner of the screenshot. This picture was placed above the two pictures of the spider web. Three letters were then placed on each picture: ‘A’ on the map picture, ‘B’ on the picture of the Lewis Hall entrance, and ‘C’ on the spider web picture. These letters were placed as text boxes, in font size 24 with black coloring. 

An inference is an educated guess as to why something is the way it is. This inference usually stems from an observation that makes you question a circumstance. For example, I observed that my friend walking out of an exam had a distressed look on her face. From that observation, I inferred that the test was difficult. I did not know for a fact that my inference was true, but I know that it is typical for someone walking out of a difficult exam to have a frustrated look on their face. In this case, my inference was correct; I confirmed my inference by asking how my friend felt about the exam. 

While sitting down on the bottom step of the stairs, a picture was taken of the spider web in the hole of the stair railing. A UMass Id card was placed right beneath the spider web to act as a scale for the web size. The IPhone camera was tilted upwards so that the background of the picture was a green tree; this dark background created great contrast that could be used to make the spider web show up, despite it being bright outside. After a picture was taken that captured the small spider web, another photo was taken 10 steps backwards from the Lewis Hall main entrance. This picture was angled slightly to the right, so that the Lewis entrance sign was at the top left of the picture, and the stairs and right side railing was at the bottom left of the picture. This picture would be used to understand where the spiderweb was located.

Figure 1. Jumping Spider. This jumping spider has four horn-like projections on the head. Two of the horns protude vertically from the top of the middle eyes, and the other two horns stick out horizontally from sides of the outer eyes. "Don't blink i'll jump." flickr photo by Mike Keeling https://www.flickr.com/photos/pachytime/3195623214/ shared under a Creative Commons (BY) license

The ribosome is another organelle in the cell that has an extremely important role. These tiny, but essential structures should not be overlooked, as they perform functions that are necessary for human life. Ribosomes are found on the endoplasmic reticulum or in the cytoplasm. When they are attached to the endoplasmic reticulum, it is known as the ‘rough’ endoplasmic reticulum. The ribosomes contain important RNAs named the ribosomal RNAs which help the ribosome carry out its main function; protein synthesis. This process is seen in translation; the ribosome uses the mRNA strand to form a completely new protein. From there, the polypeptide chains can be synthesized into tertiary and quaternary structures. Proteins are essential to human life and carry out a myriad of chemical functions. 

Diabetes mellitus is a disease that negatively affects the body’s ability to obtain energy from food. There are two forms of diabetes mellitus; type one and type two. Both of these types result from a defect in the negative feedback loop that regulates blood sugar levels. The negative feedback loop in a patient without diabetes works by using a sensor, effector, and control center. The pancreatic beta cells, which act as a sensor, detect an increase in blood sugar after the patient eats food. The pancreas also acts as the control center and is directed to release insulin into the blood. The insulin facilitates the reuptake of glucose from the cells, therefore, working as the effector to lower the blood sugar levels.

A patient with type one diabetes creates antibodies that destroy the pancreatic beta cells, therefore, damaging the sensor and control center of the negative feedback loop. As a result, the pancreas does not know to secrete insulin and leaves the blood glucose levels abnormally high. On the other hand, patients with type two diabetes do not have these antibodies; instead, they suffer from insulin resistance. In this case, the damaged part of the negative feedback loop is the effecter, as the cells do not respond to the insulin secretion. If the cells are not sensitive to the insulin, the glucose is not able to readily enter the cell, thus resulting in high blood sugar. In both cases, the damaged negative feedback loop fails to bring the blood sugar back to normal and can result in further complications. 

Diabetes mellitus is a disease that affects the way the human body obtains energy from food. There are two forms of diabetes mellitus; type one and type two. Both of these forms of diabetes are the result from a defect in a negative feedback loop that regulates blood sugar levels. The negative feedback loop in someone without diabetes works by using a sensor, effector, and control center. The sensor indicates that there is an increase in blood sugar which lets the pancreas, or control center, release insulin. Insulin acts as the effector, and facilitates the reuptake of glucose from the cells, therefore, bringing blood sugar levels back down to normal. However, a human with type one diabetes creates antibodies that destroy the pancreatic beta cells, therefore, destroying the sensor and control center of the negative feedback loop. As a result, the pancreas does not know to secrete insulin and leaves the blood glucose levels abnormally high. As for type two diabetes, insulin resistance leads to the increase in blood sugar. The damaged part of the negative feedback loop is the effecter, as it does not respond to the insulin. This decreased sensitivity to insulin makes the glucose not readily enter the cell and does not let the blood sugar levels return to normal after eating food.

Amino acids are the monomers of proteins and polypeptides. Each amino acid contains an amino group, carboxl group, and an R group. The structure of the R group is important in dictating the function of the protein when strung together as polypeptides. For this reason, the way the protiens are assembled is essential to its function. Through dehydration synthesis, the amino acids bind at the amino group of one acid and the carboxyl group of the next acid. This chain of amino acids is called the primary structure. However, the polypeptide string can be rearranged in a multitude of ways depending on the R groups. The protein is in its seconday structure when the amino acid chains come together to form alpha helixes and beta sheets. These formations happen through hydrogen bonding. Within the same polypeptide chain, the sheets and sprials fold on one another and bind to one another through interctions of the R group (intramolecular bonds); this is called the tertiary structure. Lastly, when multiple polypeptide formations bind to each other, they create their quaternary structure. To reiterate, each specific amino acid structure is incredibly important in carrying out the proteins function. When these proteins are under stressful environments, such as high temperatures or pH levels, they can denature in form, therefore, harming the proteins ability to carry out its specific function. When pH distrupts the protein structure, it is harming the H-bonds that make up the secondary and tertiary structure. 

It is important to note the distinction between equilibrium and homeostasis. Equilibrium refers to a specific system being balanced, while homeostasis refers to the organism as a whole being stable despite internal and external factors. In homeostasis, the factors being stabilized are vital to the organism's survival, and without this balance the organism will die. For example, when homeostasis is disrupted in an organisms body, the imbalance will likely result in disease. In order to keep homeostasis in an organism, the body uses many negative feedback loops to help a reaction go back to the "normal" balance for the body. This means that a function must decrease in order to go back to its balance and reduce its change. This occurs, for example, when the body gets a fever. The fever, or stimulus, occurs when the body temperature goes above normal. When the body temperature raises, it causes the sweat glands to start working harder in order to bring down the body's temperature. On the other hand, there are positive feedback loops that work differently. Positive feedback loops work by amplifying a change in order to get a body back to homeostasis. For example, when a female is in labor, contractions get more intensified in order to get the baby out; this induces an increase in a body function in order to get back to normal.