Science related photos

Monique

You're on to me!

Andre

You may want to read up on Moniques hobbies, drizzle,

My guess would be Caenorhabditis elegans

Andy Resnick

I'm guessing a GFP-transfected c. elegans. What's the construct?

Monique

Yes, these are transfected and integrated (by gamma radiation) constructs. Simplified, the constructs are the following:

1) myo-3-promotor::GFP (GFP expressed in the body wall muscle cells)

2) generic-promotor::mCherry::H2B (Cherry marking histones in all cells); hypodermal-promotor::GFP::TBA-1 (alpha tubulin marked in hypodermal cells); myo-2-promoter::GFP (GFP expressed in the pharynx, an easy to visualize marker for transgenic animals).

Ms Music

Oh my....... Thank you Lisab, that is VERY entertaining! I just may wind up wasting my entire Friday afternoon with that applet. Much MUCH easier than making teeny pinholes and razor blade slits. And now drizzle can make his/her own big grins. It DOES appear to have the same results as all my photos with the different pinholes or slits. The biggrin IS interesting, but a kitty face is even cooler. Must not lose my job must not lose my job must not lose my job.......

Andy Resnick

Very nice- do you/your lab make the constructs? I'm wondering specifically about the GFP::TBA-1....

Gad

Wow Lisa VERY entertaining indeed, thanks. I thought of doing a dotted circle, amazing!



Of course, my BIG grin

Andy Resnick

That is really cool- thanks for the link!

Monique

Yes we make the constructs ourselves and if certain transgenics already exist, we just cross the strains to make doubles. It really is a miracle that you can attach GFP to a tubulin monomer and have it form a functional molecule. There is a concentration dependency though, you need to titrate the amount of construct you inject in order to get transgenics, too much of it is toxic to the cell. The second picture was just a snapshot of a worm that I took when I was screening for double homozygotes of the transgenes, you should see the cells in division! Unfortunately I can't show such a picture, those pictures first need to be published somewhere else

Andy Resnick

I guess this is a science-y photo- see if you can figure it out:



I was playing around with the autofocus feature and decided to point the camera that our TV (crt display). When it focused, the moire' pattern appeared in the viewfinder- it's a pentaprism, not a LCD display- even though I could not see it normally.

It's definitely real- it moves depending on the orientation of the camera to the tv, and is not part of the electron beam- I took a series of exposures at 1/30, 1/60, 1/125, etc... and the pattern remained.

It was tricky getting the image re-scaled; the pattern is quite sharp and distinct- try to capture the phenomenon yourself- it was trivial with autofocus.

Any ideas?

Gad

Mouse trap!

Just kidding

Borek

No CRT here to check, but looks interesting.



Is it scientific enough? That's just a rock on the Swedish coast, but if you know what you are looking at, traces of the ice age are obvious. It is not just this rock, all rocks around have similar marks, and all point in the same direction. This particular picture was taken around N 58 deg 45' 32.31" E 11 deg 10' 51.87", but plenty of similar places around.

Andy Resnick

heh... yeah, I needed a white screen to get the best contrast. That is an intro shot from "Between the Lions"...

Andy Resnick

A colleague here buys scrap wafers for use as substrates- they are super-flat, clean, and absurdly cheap. He gave me one to play around with, and here's the results.

First, oblique illumination- some gooseneck lighting off to the side, using a 4x epiplan:




Two points to note: First, the etchings act as (reflection) diffraction gratings, and second, the color changes with rotation angle.

Now a photo combining oblique and epi-illumination (8x epiplan): the field stop was closed down quite a bit, and the contrast is tough because of the difference in illumination.



The difference in imaging is striking- there is no color in epi-illumination, and the contrast is reversed. This is why I have had problems taking pretty pictures using epi-illumination, unless other contrast methods (such as DIC) are employed. The other common epi-illumination contrast method is darkfield, and here's an image taken using a 16X epiplan HD (darkfield) objective- this is a 100% crop:



Clearly, I'm having trouble getting a finely focused image- the viewfinder just isn't good enough, as these fine details are not visible though the viewfinder.

Andy Resnick

Upon Andre's suggestion, I've tried playing around with an 'extended depth of focus' algorithm. Similar to (confocal) microscopy image stack manipulation, the idea is to take a large number of photos and assemble together only the 'in focus' portions, resulting an an image with both high resolution and large depth of field: two optical properties that act in opposition.

I took a series of images of a 1/32" ball bearing resting on foam, using my 25 mm luminar and my 16mm luminar, and these are the results:

(16mm)


(25mm)


I'm not happy with the results- I think there's entirely too much high-frequency noise in the edges of the foam, which may not be clear in the scaled-down images. There are ways to adjust the algorithm- just like deconvolution, there's many, many adjustable parameters, and blindly twiddling values is an exercise in frustration.

One fun aspect to the 16mm: if you can make out the purplish disc in the dead center of the sphere, that's from the frame taken when the center of the sphere was located at the front focal plane of the lens (autoreflection), which lets me image the lens itself.

Andy Resnick

Not very science-y, but somewhat interesting.

I went deep into my back catalog, and pulled out some bullets I recovered during my time as a USAF contractor- these were lying all over the place, from live-fire exercises. I don't know what type they are, but they weigh about 420 grains, which I think makes them 50-cal, probably vehicle-mounted..

As for science, call it a study in plastic deformation. Also, the high-magnification shots look very similar to modeling clay/moonscapes.

Andy Resnick

I had a few minutes to play around this week- I took some color interference photos of water on glass using the microscope (10X lens here)




This is a small section of the whole frame.

This is a variation of the method we developed back at NASA to image fluids in the vicinity of a contact line as part of a dynamic wetting experiment. The fringes indicate the local thickness of the water, and it's possible to measure the absolute thickness to fairly high accuracy. There, we used a monochromatic source and broadband mirrors instead of the dichroic filters normally present in fluorescence cubes to illuminate the sample.

Here, I used the broad-band output of a metal halide lamp through a five-color (Sedat) cube. The cube doesn't have any excitation filters- those are mounted back at the source. The dichroic mirror and emission filters are designed to allow fluorescence with multiple fluorochromes, and without using an excitation filter to select a particular color, I can basically use the cube as a broadband mirror.

An important point is that the source is fiber coupled- this increases the spatial coherence, which improves the fringe visibility. If I had an aperture stop in the epi-illumination path, I could probably increase the contrast even more.