kheredia's blog

In one of my first drafts, my entry was about my newly purchased aloe vera plant. It was mostly in good shape besides a few brown spots on one of the sprouts. Today it has been a month since the purchase. Unfortunately, though the plant is in average shape, it is slowly dying. The sprouts contain more brown spots, and the plant has even begun to spread. At first, I thought this was because I had not watered it, but the plant itself does not need water for at least every 3 weeks. Then I thought it was because the plant wasn’t exposed to enough sunlight. Taking it outside in the sun for a few hours a day only made the plant worse. I researched and did everything I could but for some reason the plant was not healing. This leads me to believe that the pot it is in is too small and there is not enough/not the right type of soil. This week I will be buying a larger pot and also purchasing cactus soil to see if it helps better the condition of my aloe vera plant before it withers.

Cortisol is a steroid hormone produced in the adrenal cortez of the adrenal medulla. It has many different functions in the body including, but not limited to higher blood glucose, and regulated metabolism. However, sometimes cortisol levels become too high and can cause levels of stress and anxiety. People with Cushing’s disease have been exposed to high levels of cortisol for a long time. On the opposite spectrum, Addison’s disease is a condition where cortisol levels are too low, and because of this, they rarely feel stress and as a result are unmotivated individuals.

Cortisol is also part of a feedback loop including CRH produced in the hypothalamus, and ACTH, produced in the anterior pituitary. When the cortisol levels are high, it negatively feedbacks/inhibits CRH levels and when cortisol levels are too low, it is not strong enough to have a negative feedback loop on CRH. 

My dog is an 11 year old pure bred pomeranian, weighing 10lbs and his coat is white with brown spots. His face however is mostly brown, but half of his snout is white. As he has gotten older he has developed a few white spots on his nose and the color on his nose has changed from brown to pink. 

He is a little different than the usual dog and exhibits a few behaviors that are a little less common. For one, he has a small green bed he chews on, identical to babies with a pacifier, when he is excited and overwhelmed. He is very attached to this and knows when to look for it. Some events he will grab his bed for are phone calls, laughter, gatherings at the house, when people sit around the dinner table or play games, and when there are more than 5 people in the room engaged in a long conversation. 

He was never taught how to say “I love you,” yet when the phone rings, he will howl and the vocalization that comes from his mouth is very similar as if he were saying those words. 

He knows a lot of the human vocabulary. This includes all of my family member’s names and our close friends. He knows many tricks and also knows various places in our house by name (downstairs, living room, my room, parent’s room etc) and will travel there when asked, and he knows what his bed is, and will retrieve it when asked. 

One thing that surprised me was how he learned not to leave the front yard. When he was a puppy he would attempt to escape from the front door and has successfully done so twice, but as he got older I would bring him outside and he did not pass the grass and would never go onto the street. He’s become very attached to the house such that when he comes home from a walk and you release his leash down the street, he will spring home and wait at the front door barking (impatiently) for it to be opened.

If not all family member’s are in the same room, he will do routine checkups and find each of us before going back to where he originally was. For example, If he is with me in the living room but my parents were outside and my sister was in her room, he will leave the living room occasionally to check outside, then go to my sisters room, and will come back to the living room. 

There are many more behaviors I could go into, especially his personality, but that would take a whole dissertation to write. 

Figure 1. Meerkat on alert. Meerkats work as a hierarchical system, where a few are assigned as guards to patrol the surrounding area for predators or competition from other groups. "Meerkat" flickr photo by noluckmurphy https://flickr.com/photos/noluckmurphy/6645376763 shared under a Creative Commons (BY-SA) license

The leaf I chose to represent phytophagy on campus displayed more characteristics for evidence than others I examined. The exact location of this leaf was 1 foot away from a nearby tree across from Recreational center. I was intentionally searching for fallen leaves, as I predicted they would be easier for insects to eat without having to expend much energy climbing a tree.

The leaf exhibits a dark green color. I predicted the leaf had recently fallen, due to its stiff texture. On the leaf there are various sized holes. The smallest was only some millimeters long while the largest had been approximately 2/10ths of a centimeter. Around the holes are small bumps which are discolored. They are lighter in color than the lear’s entirety, with hints of brown. This does not look like a typical display of leaf decay, so it is highly likely that those areas are where phytophagy occurred. I kept the sample with me in the case it is needed in the future.

The leaf I finally chose to represent a phytophagy example on campus had a better display more than any of the other leaves I examined. The leaf itself was from a tree nearby. I was purposefully looking for fallen leaves, because I predicted they would be easier for land insects to eat without having to expend as much energy as it would have been if the leaf was still attached to the tree. The leaf itself is a vibrantly deep green color which I had guessed had recently fallen because the texture of it was just beginning to become stiff. On the leaf there are various sizes of holes with the smallest being some millimeters long and the largest being approximately 2/10ths of a centimeter. Around these holes are minuscule bumps. The bumps have noticeable discoloration. They are a faded light green with hints of brown. This does not look like a typical display of leaf decay, so it is highly likely that those areas are where the insects ate parts of the leaf. I kept the sample with me and plan to keep it in my bag in case I need to refer back to it in the future. 

In order to find evidence of phytophagy on campus, I needed to research photos and skim a few articles so that I had enough knowledge to be able to distinguish a regular leaf from an eaten one. When I gathered enough research, I took photos of leaves around campus and compared them to ones on the internet that displayed phytophagy. By carefully comparing and contrasting, I began to eliminate the photos of the leaves that were questionable rather than clear. It was difficult because some leaves at first sight resembled photos I saw online, but they were more likely just decaying. Though there could have been evidence on those leaves, I was more interested in finding a leaf that would unarguably display phytophagy without other factors to consider. Due to the cold change in weather, there is an increasing amount of leaves dying, so I had to be very careful when determining whether a leaf had clear evidence or not. When I did determine a leaf was eaten, I would compare it to another leaf of the same species and measure the differences between the two just to be sure that the leaf I chose was a good example. 

There is a wide variety of trees, plants, and shrubs on campus that display evidence of photophagy on campus. Choosing where to go can be complicated, because there are many factors to consider. For example, students are walking around in large numbers throughout the day, whether it is on sidewalks or cutting across the lawns to make it to class. There is less of a chance to find clear evidence in areas where it is congested, because students tread over leaves and bushes that can get rid of the evidence and there will also be less bugs during the day time when there are people constantly walking over and killing them. Not to mention that being in a heavily populated area can be distracting and impede in the search for phytophagy. This is why I sought out an area on campus where considerably less students walk by and where nature is left more often untouched. I plan to search the courtyard of grass and trees in between the rec center, the Dickinson hall building and the George N. Parks Minuteman Marching Band Building. With more room to move due of the lack of people and by visiting during class time, I will have enough time to efficiently seek out various leaves on trees and those that have fallen for the evidence. 

It is often difficult to distinguish the difference between a learned behavior or something that is innate. If it is instinctual, it is present from birth and likely has evolved in an organism to better help it survive in harsh or changing conditions. For example, the Clark Jay has the ability to bury over 30,000 nutcrackers regardless of the weather and be able to retrieve 90% of them within the span of months. Their spatial learning is not a behavior that was learned over time through experience but rather is behavior that has a genetic basis. 

Another example of this is depth perception. Though they are not born being able to perceive depth. humans eventually develop the pathways needed to obtain the ability of depth perception after the age of 5 months. Otherwise, they fail to distinguish how deep something such as a ledge could be. The only difference is that it takes a little bit of time. Nonetheless, it is not a learned behavior, but rather an innate feature of mind that develops post-birth.

One classic example of a learned behavior is conditioning. A famous example of this is Pavlov's experiment with dogs. Dogs do not know to salivate when they hear a bell, but if you present food as a stimulus paired with the ringing of a bell, the dog will eventually associate the ringing of the bell with food and will salivate even if the food is not present.

A bee was found inside of my car while I was on the way to class. It reoriented its body to the driver’s side and landed on the steering wheel. This caused me to react in fear. An instantaneous physiological response occurred from the sympathetic branch of my autonomic nervous system. As a result my heart rate increased, adrenaline was released, the sweat glands on my hands were stimulated and my muscles began to contract at a rate in which my body began to shake. Action potentials were occurring at a higher frequency in order to prepare my body to escape from the stressful situation. In this state, my levels of blood calcium increased and the amygdala in my brain triggered activity in the hypothalamus. The stimulation in my hypothalamus sent signals to the pituitary gland to release the ACTH hormone into my blood.