www.photomacrography.net :: View topic - Possible bacteria swarm ring
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Possible bacteria swarm ring

 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Photography Through the Microscope
View previous topic :: View next topic  
Author Message
Thomas Ashcraft



Joined: 07 Aug 2006
Posts: 133

PostPosted: Sat Aug 12, 2006 10:35 am    Post subject: Possible bacteria swarm ring Reply with quote

Hi microscopists.

I made a hasty movie webpage of what I think is a "bacteria swarm ring."

As I live in the rural mountains of New Mexico the only information I have access to on these subjects is what I can glean from internet resources. I am teaching myself microbiology and if I am incorrect in any info I hope you will correct me!

http://www.heliotown.com/Bacteria_swarm_ring.html

Anybody ever encounter this phenomenon?

Also, I am still experimenting with efficient web movie formats. If these movies do not play for you then see the note at the bottom of the webpage. ( especially Safari browser users) I really hope the movies play without problem.

Kind regards to all,
Tom

.
Back to top
View user's profile Send private message Visit poster's website
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 18504
Location: Richland, Washington State, USA

PostPosted: Sat Aug 12, 2006 12:25 pm    Post subject: Reply with quote

Thomas,

Your movies are superb. Can I ask you to summarize what camera and video-processing tools you are using?

Thanks for posting download info about QuickTime 7.1. On Windows XP, I confirm that your movies play fine using QuickTime 7.1 with Internet Explorer 6.0.gobbledygook and Mozilla Firefox 1.5.0.6. Netscape 7.1 shows your movies as text, as you indicated that Safari might, and the same workaround applies (save to file and launch separately).

The movies also play well in VideoLAN (http://www.videolan.org/), which is a free open-source player.

They did not play for me using Windows Media Player or WinAmp.

About the bacteria, sorry, but I'm a newbie myself. Your hypothesis makes a lot of sense and the movies are pretty convincing, but I don't have anything independent to add.

--Rik
Back to top
View user's profile Send private message Visit poster's website
Thomas Ashcraft



Joined: 07 Aug 2006
Posts: 133

PostPosted: Sat Aug 12, 2006 2:15 pm    Post subject: Reply with quote

Rik wrote: " Can I ask you to summarize what camera and video-processing tools you are using?"

Hi Rik,

Thanks for the feedback and especially for testing the movies in different browsers. It seems that whatever format you use for movies there are compromises. I am leaning now towards this Quicktime .mp4 protocol because I believe it will be supported thoroughly in the near future if not presently.

My methods are : I use a Canon S3 IS still camera in movie-mode. I researched cameras and this one seems to have the best movie capability for my purposes which are these short specimen type movies specifically for a computer screen.

I record the rather large individual .avi files to a 1 gigabyte camera memory card and dump this into my Mac . ( Same process would go for PC) In the Mac I can edit the clips using I-Movie. In I-Movie then you can compress your .avi files into many different formats and qualities to make smaller file sizes for efficient sharing over the internet.

I wasn't satisfied with the basic choice of I-Movie compressions so for a while I tried the DivX compresser which was good quality but I did not like their advertising attached to my movies. Then I recently learned about Quicktime Pro 7 ($29.99 USD) which now has an improved codec/compression feature which makes a .MP4 movie. I am still working out the kinks with this compresser but it does a comparable job to DivX, (although it takes longer to execute the compression) but the final file sizes are smaller it seems.

Some people complain about the Canon S3 IS movie-mode in that it makes only large .avi files. I don't mind this. With a full quality original .avi file I can process it into various forms. I think some newer cameras will be moving to record in smaller .mp4 files only but I believe that the compression process will cause many artifacts ( like soft edges, blotchy backgrounds, hue shifts, and stuff like this.) When I compress my movies from .avi to .mp4 ( or DivX for that matter) some movies lose appreciable quality and are throwaways. At least with the original large .avi file I can have it for the future as advancements are made in compression.

I know I am forgetting a lot but feel free to ask anything else.

And thanks again for your feedback.

Tom

PS: I made a couple other sampler pages showing what the camera is capable of :
http://www.heliotown.com/Micromovies_Quicktime7.1_sampler.html
And one in DivX mode:
http://www.heliotown.com/Canon_S3_IS___Sampler.html
Back to top
View user's profile Send private message Visit poster's website
Charles Krebs



Joined: 01 Aug 2006
Posts: 5763
Location: Issaquah, WA USA

PostPosted: Sat Aug 12, 2006 3:20 pm    Post subject: Reply with quote

Tom... I see the exact thing fairly regularly. I don't know the cause, but my guess is that it has something to do with oxygen depletion under the central area of the cover slip. It is very common to find that all manner of protists and many bacteria tend to congregate toward the edges, and particularly corners, of the coverslip as the slide is observed over time. So much so that I will at times deliberately "search" the center section just to see what remains. Often not much at all. However if there happens to be a bubble of air trapped under the slip is is not unusual to find a heavy concentration of critters around the circumferance of the bubble.

The ring of bacteria that you have illustrated so well always seems to occur just a small distance in from the edge of the cover slip. There may be some sort of chemical "attraction" as the number of bacteria increase in the most favorable oxygen/nutrient portions of the slide. (No explanation as to why they don't ever seem to run right to the very edge.)
I have never noticed any ill effects on other creatures that appeared to be caused by the bacteria. Actually, I have observed a variety of creatures feasting on the congregated bacteria.

I think you have a sample the contains large numbers of certain bacteria, the oxygen level in the water is already very low, and as it decreases rapidly due to the cover slip, the more "advanced" creatures go first.
Back to top
View user's profile Send private message Visit poster's website
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 18504
Location: Richland, Washington State, USA

PostPosted: Sat Aug 12, 2006 9:33 pm    Post subject: Reply with quote

Tom, thanks for the info about video tools. It was very timely, as you can see by my other posting. I had not played with QuickTime Pro for quite a while -- long enough that my license had expired, but another $30 for a tool that solves a big problem is money well spent. That H.264 codec does work very well. The Windows version of QuickTime Pro seems to be pretty buggy -- it hangs a lot, sometimes for 30 seconds, sometimes forever -- but with occasional restarts it gets the job done.

--Rik
Back to top
View user's profile Send private message Visit poster's website
bernhardinho



Joined: 13 Aug 2006
Posts: 560
Location: Germany

PostPosted: Sun Aug 13, 2006 6:38 am    Post subject: Reply with quote

Hi Thomas,

that is an interesting phenomenen indeed. Bacteria strike back!!! Normally you would call that a very good food supply situation for the protists that use to multiply like hell in such splendid conditions. You would expect the protists feeding on the bacteria and not the other way round, wouldn't you?
The microworld never stops to amaze me!!

Bernhard

P.S. sorry, but I haven't got an explanation, by no means!!
Back to top
View user's profile Send private message Visit poster's website
Thomas Ashcraft



Joined: 07 Aug 2006
Posts: 133

PostPosted: Sun Aug 13, 2006 7:26 am    Post subject: Reply with quote

Bernhard, Charlie, Rik and everyone,

I think Charlie's explanantion is correct. I let the water evaporate down too far and the environment became oxygen deprived. Too much leaf matter and not enough oxygen exchange.

My first thought in witnessing it all was that the ring might be a predatory strategy by the bacteria since the rotifers seemed not to be able to pass through and recoiled when entering the wall of bacteria.

In any case, interesting stuff for sure.

Tom
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Photography Through the Microscope All times are GMT - 7 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group