Researchers shed new light on skin-based immune system

[AussieNeil]

One thing I've learned recently from references provided by Cllcanada and SeymourB is that our immune protection in our skin is quite different from that in our blood, though signals resulting from say a cut, do trigger the arrival of the first defenders from our blood stream, our neutrophils. Seems that there is a lot still to learn about how our largest organ - our skin, protects us from outside infection:

gizmag.com/skin-immune-syst...

Issues with skin irritations get a regular regular airing on CLL forums, so it is encouraging to know that we are gradually learning more about what keeps us protected from what's not us .

Neil

[PaulaS Volunteer]

Beautiful dragonfly...

[SeymourB in reply to PaulaS]

Indeed! Great photography!

Here in New Orleans, we call them "mosquito hawks".

[PaulaS Volunteer in reply to SeymourB]

"Mosquito hawks" sounds like a good name. Is that because they eat mosquitoes, or because they look like enormous mosquitoes?

[SeymourB in reply to PaulaS]

They do indeed eat mosquitoes.'

en.wikipedia.org/wiki/Drago...

We were always warned not to kill them, because they are beautiful and helpful insects.

[AussieNeil Administrator in reply to SeymourB]

They are certainly beautiful and extremely well designed. I've often marvelled at their incredible aerodynamics as they flit around my backyard.

I actually had a small one in my bedroom yesterday that landed on the curtain and folded its wings. Somewhere I have photos of some that glow with an iridescent blue, but the camera just doesn't do them justice. They have extremely good eyesight, making it hard to capture them up close . Occasionally some that are more use to having people around will stop for a rest and let me get a good close up like the shot above.

[PaulaS Volunteer in reply to AussieNeil]

Yes Neil - I've seen some very iridescent little blue ones too, flitting round our garden pond. (Though from Seymour's link, I think those may be actually "damsel flies" because they fold their wings, which most dragonflies don't do).

I guess their good eyesight is another similarity to hawks.

[PaulaS Volunteer in reply to SeymourB]

Thanks SeymourB. I've learnt some new things from that Wiki link.

eg. "Dragonflies are among the fastest flying insects in the world. They can fly backwards, change direction in mid-air and hover for up to a minute".

Amazing. I certainly see the similarity to hawks!

[SeymourB in reply to PaulaS]

They're really large down here in Louisiana. People can joke about "bugs in your teeth" on motorcycles, but these are something you don't want to explain to a dentist or opthalmologist ... or next of kin.

At the right time of day in the swamp, the swarms reflect the light in a nice flicker, and you can hear the hum of the wings.

I didn't realize how many different varieties there are. Usually, I see just the big green ones in the city. But there's all kinds of colors:

npwrc.usgs.gov/resource/dis...

It's a shame I have such summertime allergies. I only see the ones in the yard and near the office.