The likely mechanism controlling the interaction between fir and aspen trees is facilitative succession. This occurs to be the mechanism forwarding the secondary succession found in the example, as aspen tree density expansion allows for fir trees to be able to establish themselves within the environment. This is shown in Figure 2 as the figure shows the progression of the respective densities of the two trees in the context of the different successional stages. In Figure 2 it shows that aspen trees are able to establish themselves in meadows and in turn increase in density until aspen trees are able to grow and eventually overtake them density wise. Aspens allow for the conditions that that lead to fir population growth, thus showing the facilitative succession that is occurring. Figure 3 also shows that facilitation succession is occurring. In the experimental circumstances created by the scientists, aspen trees were thinned leading to mortality (or rate of death) for fir trees to increase drastically when compared to the control scenario. This demonstrates that without a significant aspen tree density, the mechanism of facilitation that allows for the fir to grow cannot occur. The reduced aspen tree density is unable to support fir tree growth and survival as it typically would, leading to an increased rate of mortality for fir trees, thus indicating the mechanism that controls the interactions between firs and aspens.
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Under the control situation for the experiment in question, where the aspen population was not thinned by the experimenters, mortality rates for both aspens and firs both remained at approximately 5% mortality. In the experimental scenario where aspen tree populations were reduced aspen mortality remained around an approximate 5% mortality rate while fir trees saw a massive increase in mortality rate, with a rate of approximately 22%. This increase in mortality for firs most likely occurs as aspens initiate the earliest stage of secondary succession in open meadows created by fire or deforestation, which in turn allow for firs to grow. Thus, when aspen density is reduced by experimental thinning firs are unable to grow successfully, increasing mortality significantly.
Ulva lactuca and Gigartina canaliculata are two seaweeds that interact within their shared environment. In an experiment scientists observed, tracked, and graphically represented the presence of G.canaliculata in two separate scenarios, one in which U. Lactuca was removed from the environment and one in which U. Lactuca was present. In the presence of U. Lactuca G.canaliculata was able to thrive in environment with a significant number of recruits, while the removal of U. Lactuca resulted in low recruitment for G.canaliculata. This shows the effect of Ulva on Gigartina can be characterized by a facilitative successional mechanism. Facilitative succession is defined by a scenario in which one species allows for the growth of successive species in an environment, this appears to be the case here as the presence of U. Lactuca results in the growth of G.canaliculata and its removal causes the recruitment of G.canaliculata to decrease significantly in comparison to the. Since U. Lactuca allows G.canaliculata to grow more in comparison to the alternative situation where U. Lactuca is not present, this positive relationship between the two species can be seen as facilitative in nature.
When one thinks of cancer research, one visualizes rows of petri dish, isolated cell cultures (of either humans or mice) and scientists hunched over benchtops pipetting chemicals. When I heard of my assignment for the LEE-SIP internship, I imagined the same. So, I was really surprised to learn that I would be working with fruit flies and mostly in-vivo. This past summer has taught me that the learning curve of doing research in a lab is exponential and continuous. I have already learned so much, yet there remains so much more to investigate. I have looked into the role of ABC transporters in effluxing chemotherapeutics and facilitating drug resistance. And, I want to understand more about the various regulatory defense mechanisms of our cells and their interaction with toxins. Not only does this research tie in with my current interest in genetics and cell and molecular biology, it also accommodates my future aspirations as an MDPhD candidate. The experiments I am conducting now has valuable implications for future usage of chemotherapeutics and the interaction of cell and molecular biology with environmental science and toxicology.
The presence of fat makes the immune surveillance systems fail, a group of cells whose function is to destroy cancer cells. Research, led by Trinity College in Dublin has discovered new links between obesity and cancer, which explain why the body's immune systems fail to fight cancer cells when there is an excess of fat. The study, published in the journal Nature Immunology, analyzes the causes why the presence of fat makes fail the immune surveillance systems, which are formed by Natural killer, a type of natural killer cells whose function is to destroy cancer cells.
People with excess weight are more likely to suffer from type 2 diabetes, cardiovascular diseases and a wide range of infections, in addition to the fact that up to 50% of certain cancers are attributed to this pathology. Of course, there should be more ways to understand the ways in which obesity causes cancer and leads to other diseases and, therefore, to develop new strategies to prevent its progression.
The birds within the experiment went on two, ten day long trips over the ocean. The results showed that when the birds were on land, both hemispheres of the brain exhibited regular sleep wave activity on both sides. This means that both hemispheres were inactive at the same time. The results also proved that when the birds were flying for long durations of time, the hemispheres would alternate in activity. At most times there was one hemisphere exhibiting sleep waves while the other was exhibiting waves consistent with regular activity.
The electron transport chain is the first stage of oxidation phosphorylation. During this phase, Complex 1 strips the electrons off of NADH and Complex 2 strips the electrons of FADH2. These electrons are then donated to coenzyme Q, which in turn donates the electrons to complex 3. Complex 3 then proceeds to donate its electrons to complex 4 which donates to the final electron receptor, oxygen, producing H2O. During this process, complex 1, 3, and 4 pump protons into the intermembrane space and create a concentration gradient. This concentration gradient is used to power ATP synthase, as the protons will naturally flow to an area of lower concentration on the interior of the mitochondrial matrix. To do this, the protons pass through ATP synthase, which rotates its mechanism and powers the synthesis of ATP. For every 3 protons which passes through ATP synthase 1 ATP is generated.
This experiment was successful in showing the wide variety of organisms found in biofilms that form on a toothbrush. Using selective and differential agar plates, a total of 9 different colony morphologies were observed from the same source of inoculum. This clearly shows that a variety of organisms can be present in a biofilm simultaneously. If the toothbrush had been put in the saline immediately after being used by my lab partner, I would expect the number of colonies to increase significantly. I think that due to the toothbrush drying out between the time it was used and the time it was put in the saline, the number of microorganisms available to be captured from it decreased. Despite this, this experiment clearly shows the bacterial diversity present in our mouths and on biofilms on our toothbrushes.
Purpose: The purpose of this lab is to remove water from a reaction mixture to form an ester. As water
is removed, the equilibrium is upset. The ester that is being prepared in this experiment is n-propyl
The C structural Formulas for Alcohol and carboxylic acid were drawn out. Using
densities, the proper amounts of carboxylic acid and alcohol were determined. The proper amounts of
0.974 mL of propanoic acid and 0.823 mL of 1-propanol were determined to be used for the experiment.
The volume of the propanoic acid and 1-propanol were measured and placed into a 5 mL round-
bottomed flask. 2 drops of sulfuric acid were added, while swirling. Then, for heating boiling chips were added. A distillation apparatus was set up which involved a distillation column, condenser, and side-arm. The flask was heated to a gentle boil, then refluxed for 15 minutes.
After 15 minutes to cool the contents, the round-bottomed flask was raised from reflux. The apparatus was also
allowed to cool briefly and the apparatus was then tilted allowing the water and other distillate to drain back
into the round-bottomed flask. Density causes the water to seperate from the distilate and stay in the side arm when tilted. Before being refluxed again, the distillate was drained back into the round-bottomed flask, while the water stay in the side-arm. The round-bottomed flask was lowered back into the sand bath and allowed to reflux for an additional 15
As detailed above, solid industrial wastes, mostly from combustion residues, act as possible sources for mineral sequestration of carbon dioxide. Cement production and used concrete are capable of this sequestration and similar processes that occur during the carbonation reaction also occurs with the waste material from steel slag. This offers another potential source to combat emissions produced during the production of these industrial products and store the greenhouse gas as a stable product. The benefit of using this material is its proximity to the point sources of carbon dioxide, which is to say the waste steel slag is produced alongside the steel product. Accompanying the closeness to the source of carbon dioxide release is the lower cost in using the steel slag than mining ore for natural sequestration.