Answer:
a. Odds ratio = 1.58
b. Inasmuch the odds ratio is greater than 1, this means that higher odds of melanoma exist in people exposed to indoor tanning, than in those not exposed to indoor tanning
Explanation:
For case study
Let 'a' represent the total population of people with melanomia = 696
Let 'b' represent the total number of people with melanomia exposed to indoor tanning = 1107 – 696 = 411 people
For control study
Let 'c' represent the total population = 1500
Let 'd' represent the total number of people not exposed to indoor tanning = 1500 - (0.428 * 1500)
= 1500 - 723
Total number of people not exposed to indoor tanning = 777 people
a. Odds ratio = (a/b) / (d/c) = (696/411) / (777/723)
= 1.69 / 1.07 = 1.58
b. Inasmuch the odds ratio is greater than 1, this means that higher odds of melanoma exist in people exposed to indoor tanning, than in those not exposed to indoor tanning.
True. Greenhouse gases are composed of many molecular components that provide and are necessary for life to still exist on earth. For example, the carbon dioxide and the others alike. However, when these exceed the necessary level and amount in the atmosphere, they cause tremendous increase in temperature.
Answer:
The mixing of fats with water, assisted by molecules that have both nonpolar and polar ends, is called <u>emulsification</u>
Hope that helps!
Answer:
The simultaneous effect of a predator population on a prey population and a prey population on a predator population over time.
Explanation:
The mathematical models of Lotka-Volterra equations explain the existing interaction between species in which prey and predator influence and affect each other. The model follows a few assumptions,
- The ecosystem is isolated and closed. There is no migration.
- The whole individuals are reproductively equivalent.
- In the absence of the predator, prey shows an exponential growth rate. The prey is in the ideal environment.
- When there is no prey, the predator population decreases exponentially because of the lack of food. The predator environment is ideal, but it is limited by prey density.
- The predation rate is proportional to the encounters rate, which also depends on density.
- The predators affect the prey populations, inducing its decrease proportionally to the number of prey and predators present.
- The prey population also influences the predator population proportionally to the number of encounters between the two species.
In these equations, the variable D is the number of predators, and P the number of prey items.
The parameters are always constant:
• r1: prey growth rate.
• a1: predator hunting success.
• r2: predator growth rate.
• a2: the success of the predator in hunting and feeding.
In nature, many factors affect interactions, such as dense-dependent factors and dense-independent factors. Also, in reality, there are stochastic factors. Stochasticity refers to the variability in the system involving those factors that are affecting or influencing population growth. Stochasticity might be related to good years and bad years for population growth.
In real situations, the compliance of the whole assumption does not occur. The previously mentioned constants might vary, constantly changing the interaction between the predator and the prey. These parameters change in different degrees, resulting in varying circumstances for both species.
