Ultraviolet-a/b Advanced.

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BioStimz

BioStimz

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UVA led sources are relatively common and cheap however the shorter wavelength devices are quite expensive. Of course, someone could put a phosphor on a COB that would emit in that range if they can get the proper energy stimulation source
Why would you want to add supplemental UVA?
 
BioStimz

BioStimz

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i dont even recommend the wands because people use them too much and in very unsafe manners.
I heard those UVC-wands come with free
DNA-lesions & double-strand breaks ; )

~
 
GT21

GT21

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I heard those UVC-wands come with free
DNA-lesions & double-strand breaks ; )

~
It causes a bulge in a dna helix. If you get alpha or beta partical or even x rays mess you up pretty good ... Uvc is getting close to gamma and x rays.
 
Ignignokt

Ignignokt

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[Q
Why would you want to add supplemental UVA?

Clear, blue sky sunlight has a ratio of UVA/UVB of about 10 to 1. The UVB exposure causes a certain amount of damage. UVA light is linked to activating repair mechanisms. Proper reptile lamps are a good proxy for the spectral distribution ( UVA and UVB are still ranges of specific wavelengths ).

Here are a couple of papers that talk about this at a *very* detailed level. I'm still looking for one other paper that described the UVA role better.

https://www.gla.ac.uk/researchinsti...ts/theplantuv-bphotoreceptoruvr8/#d.en.248631

http://www.pnas.org/content/102/50/18225
 
BioStimz

BioStimz

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UVA light is linked to activating repair mechanisms.
Actually.... adding UVA to a grow is linked to trichome-mutations and heritable pre-mutagenic DNA lesions.

Let me know if you need some citations.
 
BioStimz

BioStimz

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Co-exposure to the UVA-spectrum significantly diminishes the increase in trichome-density that you'd normally see from a dedicated high-output T5 UVB-setup.

"If the UVB photon is missing from the light stream, or the intensity as expressed in µW/cm2 falls below a certain level, the phytochemical process will not be completely energized with only UVA photons which are more penetrating but less energetic, and the harvested resin spheres will have mostly precursor compounds and not fully realized THC.

Examples of an environment where the UVB photon would be missing from the light stream include all indoor cultivation"


Accumulation of Cannabinoids in Glandular Trichomes of Cannabis(Cannabaceae)
Paul G. Mahlberg &Eun Soo Kim
Pages 15-36 | Received 25 Apr 2003, Accepted 14 Nov 2003, Published online: 25 Sep 2008

https://www.tandfonline.com/doi/abs/10.1300/J237v09n01_04
 
BioStimz

BioStimz

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While interesting, this does not apply to the plant kingdom. Nice try though. :)

Speaking of nice tries.... you might wanna start hitting the textbooks:


"AIl types of UV radiation are known to damage various plant processes. Such damage can be classified into two categories: damage to DNA (which can cause heritable mutations) and damage to physiological processes.

UV-C radiation has been used as a mutagenic agent in plants, and it is known to reactivate the maize Mutator transposable element (Walbot, 1992).

To prevent mutation and/or cell death, UV radiation-induced DNA damage must be repaired before DNA replication. Repair of UV radiation-induced lesions may be of particular importance in plant pollen, especially in wind-pollinated species (Jackson, 1987).
"

Molecular Mechanisms of Ultraviolet Radiation-Induced DNA Damage and Repair
Rajesh P. Rastogi, Richa, [...], and Rajeshwar P. Sinha

~
 
BioStimz

BioStimz

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While interesting, this does not apply to the plant kingdom.

UV-A and visible light energy (up to 670–700 nm) are able to generate singlet oxygen that can damage DNA via indirect photosensitizing reactions [13].

13. Alscher RG, Donahue JL, Cramer CL. Reactive oxygen species and antioxidants: relationships in green cells. Physiologia Plantarum. 1997;100(2):224–233.
 
BioStimz

BioStimz

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The UVB exposure causes a certain amount of damage. UVA light is linked to activating repair mechanisms. I'm still looking for one other paper that described the UVA role better.

What you are describing is UVA being utilized as an energy source for photorepair of UVB-induced DNA damage by enzyme photolyase.

However --> There's a threshold for UVB-induced DNA damage.

Adding a dedicated UVB-source for increasing trichome-density is done with limited-exposure.

Adding a dedicated UVA-source during this process is counterproductive.

~
 
Ignignokt

Ignignokt

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UV-C radiation has been used as a mutagenic agent in plants

UV-C is not present at the earth surface. And ya. Its bad stuff. Pulling that out does not make your argument. It is important not to conflate the properties of the various wavelengths in the discussion.

My point is that human physiology is not even a good proxy for what happens in photosynthetic organisms. And then there are other factors in plant response from ancient environments where plants have adapted to conditions where the ozone layer had been destroyed, where carbon dioxide levels rose to levels that humans cannot tolerate (~4000ppm) and average temperatures were some 10 degrees centigrade higher than what they are now. These genetic responses are exploited by greenhouse growers to maximize production.

I am interested in your thoughts however I'm not really finding any evidence in what you are suggesting for proof.

I think we can agree that plants pretty much like the spectrum provided by the sun at the earth surface. That doesn't include UV-C unless there is no atmosphere. It does include some level of UV-B and a much larger component of UV-A. We get broadband radiation from the sun and our atmosphere filters out the shorter wavelengths significantly in the case of UV-B and completely in the case of UV-C. All of the studies about plant response with UV-C was stimulated by the ozone-hole crisis a couple of decades ago where everyone in agriculture went "Oh Shit" when they realized our food sources were in imminent danger of destruction on a global scale. The science was done so the politics could get on with solving the problem - Chlorofluorocarbons. Chlorine is a nasty element when you get to know her. Reactive as fuck.
 
scubascrog

scubascrog

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One place I've watched photon technology move along that edge is in semiconductor manufacturing. We have been shrinking chip design features smaller and smaller until the minimum feature size couldn't be imaged with anything but very short wavelength 'Deep UV'. The wavelength of the light used in the lithographic process became the limiting factor for down-scaling in complex CPU device manufacturing. It also helps they have loads of cash to throw at the problem, the sources are quite expensive.
Haha funny you say that. I built plasma reactors for lam research, PECVD is getting pretty damn insane with ALD replacing everything now. dont want to stand next to our gammas when they are running, you wont have any boys for the rest of your life! lol
 
Ignignokt

Ignignokt

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Haha funny you say that. I built plasma reactors for lam research, PECVD is getting pretty damn insane with ALD replacing everything now. dont want to stand next to our gammas when they are running, you wont have any boys for the rest of your life! lol
The trouble Intel has been having with 10nm process is no doubt a part of that replacement. I don't follow the journals like I used to do, I got hooked back when ram required 3 voltage sources to work. Folks don't know how much of technology is like being really, *really* good at spinning plates. It starts out kinda sketchy until you figure out the problems.
 
45North

45North

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UV-C is a destroyer! Pollen, mold, virus any biological. Not a toy to be taken lightly.
Treat it like a nuclear power plant.
It can be USED safely but mistakes are permanent.
45N
 
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