Writing in Biology - Section 1

The amount of sun exposure varies between areas of high elevation and low elevation; in addition to flat areas. Using basal area and density as a measure of above ground biomass is important to ecology in predicting different types of plant growth and development within a variety of ecosystems (Chuang, et al. 2019). In general, south-facing slopes have a higher sun exposure than north-facing slopes; leading to a shorter growing season for north-facing slopes and a longer growing season for south-facing slopes (Whiting et al, 2003). The biomass of certain species is determined by a variety of abiotic and biotic factors, specifically solar radiation, and soil nutrients on a slope (Chuang, et al. 2019).Biomass and density of plants is also directly affected by the topography of the landscape that they are planted on. A study conducted on the effects of topography and landforms on the understory of a pine forest in subtropical China concluded that topography and soil properties contributed to 60 percent of the variations in the understory biomass (Xiaodong et al, 2019).

The amount of sun exposure varies between areas of high elevation and low elevation; in addition to flat areas. Using basal area and density as a measure of above ground biomass is important to ecology in predicting different types of plant growth and development within a variety of ecosystems (Chuang, et al. 2019). In general, south-facing slopes have a higher sun exposure than north-facing slopes; leading to a shorter growing season for north-facing slopes and a longer growing season for south-facing slopes (Whiting et al, 2003). The biomass of certain species is determined by a variety of abiotic and biotic factors, specifically solar radiation, and soil nutrients on a slope (Chuang, et al. 2019).Biomass and density of plants is also directly affected by the topography of the landscape that they are planted on. A study conducted on the effects of topography and landforms on the understory of a pine forest in subtropical China concluded that topography and soil properties contributed to 60 percent of the variations in the understory biomass (Xiaodong et al, 2019).

The topography of an area has a major influence in generating patterns in vegetation. There is scientific evidence showing that the topography of landscapes affects the growth rate and biomass production of plant species, specifically trees (Whiting et al. 2003). The topography of these areas, coupled with varying amounts of sunlight affects the density and the basal area of these tree species. It has been proven that areas that receive more sunlight have higher rates of photosynthesis and therefore higher rates of overall productivity (Whiting et al. 2003).  The effects of sun exposure is a large factor in total plant growth due to topographic differences.

To determine whether different habitats have different sized trees, we measured the diameter at breast height (dbh) of adult trees in three sites at the Holyoke Range in Amherst Massachusetts. The sites included a north slope, south slope and flat area at an area called  “The Notch” on the range. The dbh of these trees was used to find basal area of the adult trees present in eight replicates. After analyzing the basal area of adult trees it was determined that the average basal area was not that different between the slopes. The species Quercus rubra/velutina was also specifically looked at because of its high density at each site compared to other species. It was predicted that the basal area of this species would be larger on the flat than on either north or south slopes. It was actually found that the north slope have higher average basal area than either the flat of the south slopes. Ultimately, the results did not support the hypothesis that steeper slopes have small trees due to higher mortality rates of of larger trees.

The stability of slopes is correlated with the vegetation on that slope in regards to stability (Fan, Lai 2104). The root systems of plants play a pivotal role in the stability of a slope. Does the slope also determine what vegetation is present and for how long? This idea my help determine if trees in different habitats tend to be different sizes. The steepness of a slope can create different habitats. The difference in these habitats can be related to the variance in the steepness of slopes. It is well known that generally the larger the radial measurement of a tree is the older that tree is. A series of small trees could indicate information about the mortality rate of that species. Mortality rates may depend on the slope steepness and elevation (Bigler, 2016). This notion can be related back to the variance in tree size and certain habitats. Steeper slopes have smaller trees due to higher mortality rates of larger trees.

The stability of slopes is correlated with the vegetation on that slope in regards to stability (Fan, Lai 2104). The root system of plants play a pivotal role in the stability of a slope, but does the slope also determine what vegetation is present and for how long? This idea my help determine if trees in different habitats tend to be different sizes. The steepness of a slope can create different habitats. The difference in these habitats can be related to the variance in the steepness of slopes. It is well known that generally the larger the radial measurement of a tree is the older that tree is. A series of small trees could indicate information about the mortality rate of that species. Mortality rates may depend on the slope steepness and elevation (Bigler, 2016). This notion can be related back to the variance in tree size and certain habitats. Steeper slopes have smaller trees due to higher mortality rates of larger trees.

The domestication of animals for human use/companionship was a very long process. Since humans began forming civilizations and societies, many animals chose to stay close to human settlements to feed on any food scraps that were left behind or carelessly placed. This unintentionally recruited rodents to settlements that would not only eat people's food supplies but bring disease with them. People noticed that cats were very good at catching and killing bothersome rodents, and would entice them with food into living with/near them. Most domestication processes begin like this, with the animal in question providing a benefit for humans and in turn being rewarded with food or shelter. 

Additionally, the results show that all of the insects become active beyond 20°C. Against the null hypothesis that the insects will show a mean activity count of 10, a T-test generates a p-value of 0.096, which is above 0.05 and therefore not statistically significant. Thus, these results imply that O. fasciatus is at its most active at and above 20°C, which is 5°C above the average daytime temperature in Massachusetts.

There are a number of plausible explanations for these results. Firstly, O. fasciatus covers a wide geographical range, from southern Canada to Costa Rica. Populations of O. fasciatus therefore inhabit different environments and different temperature ranges, and it may simply be that the milkweed bugs we used came from a population that inhabits a warmer climate. Therefore, the insects wouldn’t show the most activity in the Massachusetts average daytime range of 10-20°C but rather at higher temperatures above 20°C.

Alternatively, it may be that O. fasciatus needs a continuous source of food to maintain its body temperature at levels that promote activity and that only under higher heat conditions does its body temperature rise enough for it to become active. Given that the insects were starved 12 hours prior, it may be that they did not have the energy reserves or the necessary metabolites to heat themselves. Therein, when the ambient temperature was raised to 20°C above average daytime temperature, their bodies warmed up to a temperature that promoted activity, one they couldn’t reach due to a lack of energy. The primary confounding factor of this explanation being that they were provided with food during the temperature switching portion of the experiment, and yet none of the insects were seen to forage. However, this effect may have been due to the insects being put into new temperature and visual conditions during the temperature switch, thus motivating them to escape from the arena rather than search for food.

      In summary, O. fasciatus activity is positively linearly correlated with temperature and is highest above 20°C. The data do not corroborate the hypothesis that the insects are most active at an intermediate temperature window of 10-20°C. Based on these results it may be the case that the level of O. fasciatus activity depends on its access to food, as it may need energy reserves to raise body temperature above daytime temperatures in Massachusetts in order to remain active during the day. Further research into O. fasciatus thermoregulation and potential life characteristic divergence among geographically distant O. fasciatus populations is necessary in order to elucidate the reasons behind these results.

 I wanted to introduce the Juul, a new innovative, cheap E-cigarette which packages nicotine salts from leaf tobacco into one-time use cartridges. It has become so popular that it is now about 68% of the $2 billion e-cigarette market. The Juul is a long rectangular device in which it easily chargeable, just with the addition of a USB port into your laptop or your wall adapter. The Juul had an insane market when it was first released, but the company had made it with the intention to help smokers stop using a traditional cigarette. Switching to Juul e-cigarettes reduced smokers’ risk to cigarette toxins at similar levels to quitting entirely, according to results from a clinical trial.

Recent studies have been shown that your conscious memory relies on the temporal lobe of your brain. In this region, the hypothalamus is located. Researchers have found that different types of memories are stored in different locations of your brain. When wanting to recall a certain memory, the neurons changed their activity to match the location for where the memory that you are searching for is located. Tracking these different paths that neurons take to recall a memory, researchers have been able to look at these paths and are able to tell what type of memory one is recalling.