Animal Magnetism

[donnahardy2]

Hi Alang,

Thanks for posting the rest of the data. To calculate the p values, you need to use the individual data points to calculate the standard deviation of the values. so we need the individual angles for each animal in the control and powerline groups. Please confirm the data powerline data again.; is it 68 and 46, or perhaps 54 and 46?

I will see if there is a math expert who can help with some advice.

Donna

[ALANG]

Alright I have found the Final Data.

I went in and rechecked and got these final data.

As of now I have 40 animals for both. With has an average of 47 degrees. And Without has an average of 37 degrees.

So do I use the standard deviation for the expected values on chi square?


-Alang

[donnahardy2]

Hi Alang,

Check out the original article on magneto reception in cattle and look at the circular diagrams used for displaying the data. This paper also has other useful background information for your project.

http://www.pnas.org/content/105/36/13451.full

The authors used a rayleigh test to determine the significance of the results. It will be helpful to see if the same analysis can be used for your data. The circular diagrams are very helpful in seeing the data.


Donna

[ALANG]

Hello,

Thanks for the link.

Please tell me if the following is fine.

So using the data, will it be fine if I find the average of 0 and 45, and use that as the expected value (22.5) for without powerlines. And an average of 45-90 (62.5) for with powerlines on the chi square?

If so, I found the degree of freedom and found the chi square, and found out the P value. It was shown that my data was very significant. With a P value of 0.00007951 .

How is that?

[ALANG]

~Final~

Ok here We go

Without Power Lines:!

37 degrees Average
37.5% 45-90
62.5% 0-44

With Power Lines:!

49 degrees Average
65% 45-90
35% 0-44

So to find the degree of freedom I do n-1. N is for categories. So 2 categories minus 1 is 1.

Then to find chi square, I used the average of 0-45 and 45-90 and used the answer as the expected value.

How does this sound?

-Alang

[donnahardy2]

Hi Alang,

You have done an excellent job in calculating the significance of the results using the traditional method that I had suggested.

After I reread the original reference article yesterday, I realized the original authors used a different method based on circular statistics, comparing their data to what would occur if results are random. This method, called Rayleigh distribution, and the math for this is complicated. I will try to find out if there Is a simpler method for doing this type of analysis.

What level of math are you taking at the moment? You seemed to understand the p values based on comparing the standard deviation of two groups of data. Your p values are definitely statistically significant.

Your project is due soon, so please proceed with the final write up of your results, but don't do the final pasting until we can confirm the data analysis method.

Your results section should be two half circles (one from no power lines; one with power lines) with each data point recorded on the angle from -90 to +90 degrees.

Donna

[ALANG]

Good evening,

I'm a 9th grader taking algebra 2. Ive studied a bit of statistics though.

I'll complete the conclusion and result part of the regional science fair application tonight.

[donnahardy2]

Hi Alang,

Thanks for your reply. The calculus equations required for the original analytical method are too complex for this project. I think you should be fine with the calculations you have done.

In your discussion, make sure that you evaluate the following:

1. Results of the control animals to the expected random results (percent in 0 to 45 degree angle vs percent in 45-90 degrees)

2. Results of power line grazing animal vs expected random results. (percent in 0 to 45 degree angle vs percent in 45-90 degrees)
If results were random, you would expect the distribution in the two angle groups to be equal, and your results clearly show there is a difference and more animals are aligned towards magnetic north.

3. Control group vs grazing animals. Is there significant difference between the two groups?


Good luck!

Donna

[ALANG]

Alright, Thanks I will.

How does this look for an abstract:

Farmers herding their cattle or sheep have noticed that, when grazing, their herds face the same direction. Some may believe that this alignment is due to the wind, or exposure to the exposure to the sun. Magnetoreception is a widespread sensory ability that are used by over 6 vertebrate classes. In this study, herds on google earth will be observed to determine their magnetoreception. I hypothesized that if high voltage power lines are located near herds of cows, the cows' ability to sense magnetic North will be adversely affected. To test this hypothesis I used Google Earth, Power Point, Excel, protractor. First I selected 10 pastures, 5 having close proximity to power lines, and 5 without proximity to power iines.While choosing the pastures I had to make sure that they weren't on mountain slopes, or in the immediate vicinity of human settlements. Next. I found the magnetic North by using an online tool. Following, I used the magnetic North to evaluate body direction. Finally I analyzed my data. The data shows that the closer you are to power lines the farther the angular value is to 0 degrees. It was found that 65% of grazing animals that were situated between 45-90 degrees, and 35% situated between 0-44 degrees (With proximity with power lines), while grazing animals without proximity with 37.75% of grazing animals were situated between 45-90 degrees, and 62.5% situated between 0-44 degrees. The experimental results supported my hypothesis that power lines adversely effect the magnetoreception of grazing animals.

Also this is my title: ____

Is there anything that doesn't make sense and that I should fix?

-Alang

[donnahardy2]

Hi Alang,

Your abstract is comprehensive and very good, however, it's a little long. You did include the essential elements of an abstract including the introduction, problem statement, procedures, results and conclusions. I would recommend just a few edits (deletions) to streamline it a little. What do you think about this version? It still seems a little long, so see if you can cut any more words without losing the essential meaning. The deleted sentences were good, so should definitely be in your project report.

Magnetoreception is a widespread sensory ability that is used by many animals to determine location and for navigation.and has recently been reported in cows. In this study, I studied the orientation of individual animals in herds of grazing cows using images from Google Earth. I hypothesized that if high voltage power lines are located near herds of cows, the cows' ability to sense magnetic North will be adversely affected.

To test this hypothesis I used Google Earth, Power Point, Excel, protractor. First I selected 10 pastures, 5 having close proximity to power lines, and 5 without proximity to power lines and compared the orientation of the cows to magnetic north. If magnetoreception is present, I would expect a higher percentage of animals to be between 0 and 45 degrees of magnetic north, and fewer animals to be between 45 and 90 degrees.

In pastures close to power line 65% of grazing animals that were oriented between 45-90 degrees, and 35% situated between 0-44 degrees. In pastures without proximity to power line 37.75% of grazing animals were situated between 45-90 degrees, and 62.5% situated between 0-44 degrees. The experimental results supported my hypothesis that power lines adversely effect the magnetoreception of grazing animals, P= 0.00007951

Donna

[ALANG]

Good Evening

I have looked through the abstract you wrote, and I fixed a few things such as the usage of "i". Please inform me of any discrepancies.

Magnetoreception is a widespread sensory ability that is used by many animals to determine location and for navigation, and has recently been reported in grazing animals. In this study, the orientation of individual animals were studied in herds of grazing animals using images from Google Earth. It hypothesized that if high voltage power lines are located near herds of cows, the cows' abilities to sense magnetic North will be adversely affected. To test this hypothesis Google Earth, PowerPoint, Excel,and a protractor were used. First, 10 pastures were selected, 5 having close proximity to power lines, and 5 without proximity to power lines. Thereafter, the pastures were examined and compared the orientation of the cows to magnetic north. If magnetoreception was present, a higher percentage of animals were expected to be between 0 and 45 degrees of magnetic north, and fewer animals to be between 45 and 90 degrees. After the experiment was carried out to completion, the data showed that in pastures close to power lines, 65% of grazing animals that were oriented between 45-90 degrees and 35% situated between 0-44 degrees. In pastures without proximity to power lines, 37.75% of grazing animals were situated between 45-90 degrees and 62.5% situated between 0-44 degrees. The experimental results therefore, support my hypothesis that power lines adversely effect the magnetoreception of grazing animals, P= 0.00007951.



Please look through my conclusion too:

The purpose of the experiment was to investigate the effect of high voltage power lines on the magnetoreception of grazing animals. After completing the experiment, it was shown that the data was deemed highly significant using the probability value. As the data table and circular statistic graphs show, grazing animals tend to be more aligned with the magnetic north with the absence of proximity to power lines. Grazing animals near power lines had an average of 49 degrees (65% of grazing animals were situated between 45-90 degrees, and 35% situated between 0-44 degrees), while grazing animals without proximity to power lines had an average of 37 degrees (37.75% of grazing animals were situated between 45-90 degrees, and 62.5% situated between 0-44 degrees. According to the data and results, the hypothesis was supported, i.e, If high voltage power lines are located near herds of cows, the cows' ability to sense magnetic North will be adversely affected. This experiment relied heavily on attaining data and pasture pictures from Google Earth. Perhaps this experiment could be further improved if the uncontrolled parameters are attended to, such as the type of grazing animal chosen. Additional investigations will be conducted by taking visits to various dairy farms to ensure that there is one type of grazing animal being tested. Also, future analysis could include the comparison of the alignments with the magnetic North of cows, horses, buffalos, donkeys, and deers and observing the variations.

[dcnick96]

Hello. What an interesting project. You have made great progress and have received excellent advice so far.

I commend you for trying statistical analysis before taking any courses. It is not an easy subject! I believe you want to determine whether there is a "difference of means" between your two populations (with and without power lines). The best statistical test for this type of data is the "2 sample t test." This test determines whether there is a significant difference between 2 population means. You can read more about it here.
http://vassarstats.net/textbook/ch11pt1.html

Don't panic with all the math. Thankfully, there are many online calculators that do it all for you. A good one is here.
http://graphpad.com/quickcalcs/ttest1.cfm

Certainly write back if you have more questions. You are doing great!
Good luck!
Deana

[ALANG]

Hello,

Thanks for your input. I performed the T - test and here are my results :http://prntscr.com/9x9vmb

Did I do it right?

-Alang

[dcnick96]

If you entered your data and chose "unpaired t test," then, yes. That is correct.

Now, can you interpret the results? What do these numbers mean (what conclusions can you make?) with respect to your experiment?

[ALANG]

Yeah, that's what I did .

What is the difference between paired t test, and unpaired t test?

What does the T, DF, and standard error of difference mean under Intermediate values used in calculations?

What exactly does SD and SEM mean?

Other than that. I can conclude that my hypothesis was proven correct and that grazing animal's magnetoreception is affected by powerlines.