The first paper titled: Origin matters: widely distributed native and non-native species benefit from different functional traits uses some generic headings such as introduction or materials and methods,. however it also uses some sub headings in larger sections to help organize its information. As an example the materials and methods section has a new heading whenever a new aspect of the study is being discussed, such as moving on from species selection, to what traits of that species will be looked at. Another thing that I noticed about this article is that the same sub heading will be used under two different main headings to explain how different aspects relate to each other throughout the paper.In the second paper titled: Non-native species and rates of spread: lessons from the brackish Baltic Sea there are fewer headings and far fewer subheadings used. Compared to paper 1 all the different aspects of the things being looked at are not separated by subject. While they both use headings to clarify what is being talked about, the second paper’s structure is harder to follow. One paper is more of an amalgamation of studies designed to talk about the effects of invasive species and the characteristics that lead to both their survival and the survival of native species and the other looks at the rates of invasive species in particular areas. Both papers are structured to discuss relevant information and then present their findings in organized ways.

In this study, twenty-four young and older men and women participated. All subjects were matched for physical activity. Biopsies from the vastus lateralis were taken from each subject and imaged using electron microscopy. These images were provided by collaborators at the University of Vermont. Images were then analyzed using a protocol to identify intramyocellular lipid droplets within the muscle fiber. Lipid droplets were identified using the criteria as follows; a gray/white interior, somewhat circular in shape, contains a gray outline, doesn’t have multiple membranes on the outside or have debris inside, and usually adjacent to mitochondria. A protocol was then developed in order to create a thresholded image containing only lipid droplets. These thresholded images were then analyzed for circularity, area ratio, roundness, solidity, and % area. using ImageJ. This data was collected and cross-checked between multiple (2) undergraduate researchers.

    Intramyocellular lipid content is not only used as a source of energy in adipose tissue, but also in skeletal muscle. It has been shown that during prolonged exercise, IMCL content decreases as the lipid content is transformed into energy. Similarly, prior to routine exercise, trained athletes exhibit elevated amounts of IMCL content within skeletal  muscle in order to compensate for the amount of energy that is regularly used and lost during exercise.  

    Previous studies have found that older men tend to have larger IMCL droplets and fewer droplets when compared with other groups (Crane et al. 2010). Based on these studies, it is expected that such variation in IMCL content is responsible for the differences in mitochondrial function and lipid metabolism between the young and older populations.

It is understood that within human muscle fibers there exist lipid droplets which are known as intramyoceullar lipids (IMCL). There have been numerous studies which have investigated the difference in intraymocellular content, but none have been matched for physical activity as our data has been matched for physical activity.  It is thought that older men have larger IMCL droplets than young adults. Additionally it was previously determined that older adults have a lower percentage of IMCL in contact with mitochondria as compared to young adults (Crane et al. 2010). Furthermore, trained athletes have a high IMCL content which is countered by having a greater concentration of mitochondria.

The purpose of this study was to examine the effect of age and sex on IMCL content within skeletal muscle. Identifying such relationships between IMCL content and other variables such as age and sex while being matched for physical activity can reveal relevant information regarding why IMCL storage in skeletal muscle is important for physical performance. From a clinical standpoint, examining factors that influence lipid size in respect to aging and sex differences can be beneficial in designing interventions to improve lipid metabolic efficiency.This in turn would increase the availability of energy to skeletal muscles, allowing for increased physical function.

    Intramyocellular lipid content is a source of energy used within skeletal muscle. In this study, EM images of the vastus lateralis were taken for twenty four subjects who were matched for physical exercise. These EM Images were analyzed for IMCL content using GIMP and ImageJ programs. Based on the analysis we found that there was a age by sex difference in IMCL lipid area older women were found to have a much lower IMCL lipid area than in younger women.

The article Origin matters: widely distributed native and non-native species benefit from different functional traits had similarities and differences to the previous article. Similarly, this article has level 2 headings that include introduction, methods and materials, and discussion. There are also some subheadings that help the author divide up the different elements of the methods, like “Trait selection” and “Trait interaction models”. The divided subsections helped make the paper easier to follow. Just like the previous article, in the beginning of each section, there is an introduction paragraph that shows the reader what the section will entail. However, in this article, one of the introduction sentences to these introduction paragraphs has a rhetorical question. This article was concise and had good flow, however it did not flow as well as the other article. This article follows the IMRAD format exactly.

the sensory systems collect signals in the environment and convey them to the CNS
sound: change of air pressure
- action potential can upkeep an amplitude for a long distance because it can regenerate itself due to the Na+ channels
- amplitudes don’t differ in the same neuron, but can differ across neurons
- action potential doesn’t carry info, it is the timing (the signal is digital)
- change in the environment provide signals (light, chemical, mechanical)
Mechanical = Touch and Hearing (hearing is the movement of physical objects, no physical contact)
Chemical = Olfaction and Taste
- conversion happens in 3 steps
1. electrical signals of the environment converted into receptor potential
2. needs to be sensed by a receptor, becomes converted into electrical signal in the receptor = membrane potential = receptor potential (if it happens in the receptor)
- receptor potential is incremental and is reflecting the signal in the outside
3. receptor potential converted to action potential along the afferent fiber (action potential is digital = can propagate long distance w/out changing amplitude
What is in common?
- parallel processing in multiple pathways, work in parallel, in any given time, all of them are telling something to the brain, true for all sensory systems
- two steps processing
- the difference is the receptor, convert external signals into incremental change
(axon terminal = receptor potential at a receptor, variation among type of sensory system)

In the article, Non-native species and rates of spread: lessons from the brackish Black Sea, there are mostly level 2 headings. These headings include the usual headings, like abstract, discussion, and acknowledgments. In addition to that, it contains other level two headings, like “Rate of secondary spread within the Black sea” and “Vertical spread”. These headings provide more specific sections of the results piece of the article. The first paragraph of the introduction section starts out broad to get the reader engaged and then it gradually becomes more specific. However, in the individual sections that include the results of the experiment, the information does not start out as broad. In these sections, the author jumps right into the data. This article follows the IMRAD format that was described in chapter 7. At the beginning of most paragraphs, there is a topic sentence which informs the reader what the author will be discussing. This is especially helpful when the author is describing different species in the results, like B. improvisus and P. antipodarum. Finally, this article had concise paragraphs with good flow, similar to the examples that were given in chapter 3. 

The purpose of the methods project is to test whether one's written experiment is sufficient to be replicated by another party. This is an important skill to have in the field of biology because any work that is published needs to be able to stand alone; there is no explaining what you've done, only the paper is able to guide someone else. This project needs to be reasonable enough for someone to try, detailed enough for someone to understand and thorough enough for someone to reach the same results.

The abstract sections of each of the articles were about a paragraph long. The textbook writes that the overall structure of the abstract should conform to the following outline: “content: question/purpose, experimental approach, results, interpretation/answer, significance” (pg 115). Considering that both of the abstracts are only a paragraph long compared to the other sections (the introductions are several paragraphs long), it seems kind of impossible to accomplish this. Yet, the writers of both articles were able to provide a thorough paragraph with all essential parts included. The article from the Ecology Letters journal contains the topic sentence as the first sentence and there is a logical flow of ideas. It is organized by giving the background sentence first (the known), the two sides of argument. Then, what the researchers are trying to accomplish (the unknown), their approach, the conclusion they came to and last but not least, their interpretation of their results. The other article’s abstract is somewhat different since it is not necessarily an experiment but rather just an interpretation of several other experiments in order to answer their hypothesis. There is no topic sentence, but the first 4 sentences provide the reader with a background that gives the purpose and of their research so, they could be seen as topic sentences of significancy. There is no experimental approach because this is not an experiment but they do state that they are going to approach their hypothesis by reviewing (comparing and contrasting possibly) the invasion histories of several species. There is a logical flow of ideas and overall, the abstract is well organized.

In the article titled, “Origin matters: widely distributed native and non-native species benefit from different functional traits,” there are a variety of headings and it follows the IMRAD format as discussed in our book. This contains an Introduction, Materials and Methods, Results, Discussion section and sometimes an abstract is included. Since the paper is formatted this way it aids readers in identifying a particular section they want. In choosing such a format it shows that the paper illustrates structure and organization. Their abstract addresses the topic they will be addressing and what they were looking to find in the studies performed. This research paper also shares similar features that are included in the article, “Non-native species and rates of spread: lessons from the brackish Baltic Sea.”