DLR 2: Histology – Results
Instructions
We Are All Responsible for Maintaining Academic Integrity
Read the Academic Integrity section of this Pressbook, including the resources we have provided.
While you are responsible for ensuring you do not commit academic dishonesty (e.g. plagiarism, inappropriate collaboration) according to any of the relevant offenses and explanations listed in McMaster’s Academic Integrity Policy (e.g. section 18 and Appendix 3), we have provided additional details regarding expectations for the LIFESCI 2L03 assessments. You are responsible for reading our expectations in regards to appropriate academic behavior (e.g. for group vs. individual work) and how to reference sources of information for individual assignments.
In order for your assignment to be graded, you must acknowledge on the assessment cover page that you have read the Academic Integrity section of this Pressbook and our expectations (see the links above). The cover page template provided to you contains this acknowledgement.
Refer to the ‘Results‘ section of the lab report writing guide for details on how to prepare this section
- This LRWG section, in addition to this assignment overview page, acts as the SPECIFICATIONS for what we are expecting for a submission to be graded with a pass
- Recall that DLRs are graded as pass/fail
- If you do not submit this assessment, it will be noted as 0 in the Avenue to Learn gradebook
- A submission that does not meet the specifications will receive a fail (noted as a 1 in the Avenue to Learn gradebook)
- A submission that meets the specifications will receive a pass (noted as a 2 in the Avenue to Learn gradebook)
- A submission that exceeds the specifications will receive a pass (noted as a 3 in the Avenue to Learn gradebook)
- These numerical notations are not percentages, scores, or anything that can be used to mathematically calculate a new value. In fact, a 2 and a 3 are identical when we record your final letter grade at the end of the semester.
- You should refer back to the GradeGrid if you want a refresher of how DLR completion is used to determine your final letter grade in the course at the end of the semester
- As you can see, a results section of a lab report contains both processed data (in the form of figures or tables) as well as text that describes the data and trends in words. You will refer back to the figures and/or tables as you describe the data. You should be careful not to try to explain why a certain trend is shown – that type of interpretation belongs in the discussion section.
For this DLR, you will be constructing a formal results section of the lab report. This will include two figures and the supporting text. A figure caption is NOT the same thing as results text paragraphs – these components should both be present in your DLR. You will find it helpful to refer to the example of text found in a results section in the LRWG linked above. Ensure your text refers to BOTH figures – you may consider one paragraph per figure, or you may prefer to combine it into one paragraph.
Figure 1
- Prepare a research quality figure containing three panels which are representative images of:
- Panel 1: 5-day old mouse skin sample
- Panel 2: 30-day old mouse skin sample
- Panel 3: 2-year old mouse skin sample
- Label the tissue layers for the mouse images (and other structures you can see in these images, such as adipose, hair folicles, blood vessels, etc. The lecture may be helpful in identifying different tissue structures.)
- Include a scale bar
- You can use any software to make the figure (e.g. MS PowerPoint, ImageJ)
Refer to the ‘Results: Figures and Tables‘ section of the lab report writing guide for details on how to prepare a figure and caption
- Click for an example of a figure of an image
- Remember – a figure includes both the image and a caption!
Figure 2
- Prepare figure 2, a graph comparing the mean thickness of the dermis and epidermis of skin samples from mice of different ages (5-day, 30-day and 2-year)
- Measure the thickness of the epidermis and dermis from ten (10) different regions of interest (ROI) in each of the three tissue samples (5-day, 30-day and 2-year mouse skin). You will select the 10 ROIs from the 5 images that you captured during the lab per mouse age.
- Use the image of the stage micrometer which was captured at the same magnification as the corresponding mouse skin images to calibrate the scale in ImageJ before taking your measurements. Recall: the stage micrometer is a tiny ruler.
- After taking the measurements from the images, calculate the mean thickness and standard deviation of the dermis and epidermis for each mouse skin sample (5-day, 30-day and 2-year) and construct your graph.
Refer to Appendix B: ImageJ and watch ‘LSL Video – ImageJ Part 1’ which demonstrates how to add a scale bar, calibrate the measuring tools, and take linear measurements in ImageJ
- Download and install ImageJ on your laptop: Go to: http://imagej.nih.gov/ij/download.html and choose the download that corresponds to the platform (Windows, Linux or Mac) you are using.
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When opening ImageJ on a Mac for the first time, there is a safety feature that will prevent you from opening the application as it is from an unidentified publisher. To bypass this:
- Double-click the application and HOLD the Control button until a prompt appears to either Open or Close ImageJ.
- Click Open and ImageJ will load (Note: you only have to do this for the first time)
Refer to the ‘Results: Figures and Tables‘ section of the lab report writing guide for details on how to prepare a figure and caption
- Click for an example of a figure of a graph
- Remember – a figure includes both the image and a caption!
Refer to Appendix A: Microsoft Excel for a demonstration on how to use Microsoft Excel to analyze data sets and prepare graphs.
- Results text must be 300 words or less (figure captions and cover page are not going to be included towards this word count). Anything written after the word limit will not be considered when assessing your answer.
- NOTE: Your DLR assignments MUST include the course cover page in order to be graded. Failure to include the cover page will result in a failed assignment. We require the cover page because it serves as an agreement that you comply with the course academic integrity policy.
