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Wednesday, July 27, 2016

SO LONG, PHILAE!

Goodbye Philae! by PiPs, Bernards & by @sciencemug
Goodbye Philae! by PiPs, Bernards & by @sciencemug

Today's the day when, to save its power [(which is lower and lower given it's generated by solar pannels and the Sun is 520 million km (and going) away now)], European Space Agency (ESA) spacecraft Rosetta (the piece of human immagination, technology, intelligence, hard work and ambition which for ten years (2004-2014) chased, and finally, on 6 August 2014, reached Comet 67P/Churyumov-Gerasimenko) is switching off the tool used to communicate with its lander Philae, which is on the comet and silent since last summer (9 July 2015).

Goodbye, lander-pal Philae, enjoy your slumber and your view.
And thanks for all the fish... No, sorry... For all the amazing science and your epic landing!

The sciencemug gang.

Wednesday, July 13, 2016

BACTERIA vs HUMAN CELLS: 1 to 1 (FINAL) PT3/3

(PART2)
  
Don't lose the brand-new
"Oddities & Bloopers: The Researcher's Fun Corner"
at the end of the post!

Ooooh, welcome back for the third -and, I do promise, last- time in this topic, dear English thinking-reading visitor. I’m @sciencemug, the blog/twitter-account/podcast (on occasion)/e-shop that tells you science stories, competes in the “2016 Combing-Stylist For Bald People Contest (2016C-SFBPC)” (with serious possibilities to get to the semifinals against a url of Tuvalu specialized in doing the perm to invisible wigs for particularly unsettling ceramic dolls) and that does all of it in Eng?ish, a language that is to real English what Brexit and this are to good ideas.




In this post, dear visitor, it is going to end the story about three scientists (Mr. Sender, Dr. Fuchs, Prof. Milo, aka the SFMs) who debunk the myth that, in the human body, bacteria outnumber human cells by 10:1.

The SFMs (by @sciencemug)
The SFMs (by @sciencemug)

The SFMs first find out the actual number of bugs living in/on the body of a refernce human being (an healthy, adult, 1.70m high, 70kg heavy, 20-30 years old male aka Mr. Ref): 3.9x1014.
The science trio, then, calculates the number of human cells that make Mr. Ref’s body:
3x1014.

Oh just to clarify dear listener, 10 to the 14 means a 1 followed by 14 zeroes, which means your human body is made of 1hundred thousand billion cells. In the Milky Way there are, NASA says, about 1 hundred billion stars, meaning that the cells that make your body, dear human listener, are 1 thousand times more than aaaall the stars that make the whole galaxy...

Ok, let’s procede with the post.
After calculating the just menditoned numbers, our fine researchers can thus show that the real bacteria vs human cells ratio in the human body is not 10 to 1 as thought for ages, but indeed an almost perfect 1 to 1, which is a ratio so finely balanced that every time one of you, dear human beings, goes number two, well, human cells end up winning the ratio-competition since every “number two initiative” means loosing 1/3 of the members of the bacteria gang!
 

Sooo to finish the story of the SFMs, dear visitor -and for this blog to go back and train for the 2016C-SFBPC which first prize is a tour of all the forty nine major sites of the dominion “.havingaballohyeahbigtime”- only the two questions you, smart-ass visitor, probably asked yourself, your “monster from the ID” of reference and, implicitly, me, must be answered:
1)Ok, the ratio is 1:1 in […] Mr. Ref, but what about the non-Mr. Refs all around the world, like […] women, overweight people, babies?
2)WHY?! Why [the SFMs] invest so much time in understanding what’s the actual bacteria:human-cells ratio in the human body [instead of, I dunno, looking for answers to some essential biological and philosophical questions of life, like, for instance, the reason why your dearest bladder always tells you that you have to pee the exact very moment you start being in/into a place/situation/piece of apparel which does not allow you to pee]?


Weell, dear visitor, here come the answers.
 

Answer one. As you, by now, know, the bacteria vs human cell ratio basically depends on: colon volume (CV) & bugs density in the colon (BD) for the bugs side; number of Red Blood Cells-Erythrocytes (i.e. the hematocrit; He) & blood volume (BV) for the human cells side.
Ok? Ok!
 

by @sciencemug
by @sciencemug

So, let’s start with women.
A “standard” 1,63m tall [according to the 2002 Publication by the International Commission on Radiological Protection (ICRP2)(1)] mirror of Venus [aka Lady Ref] has a CV of  about 430ml, that is similar to the about 410ml CV of the standard 1.70m Mr. Ref.
As for the BD, well visitor, science literature doesn’t report, so far, any gender-specific differences about this parameter.
Let’s go to the He and BV now. Lady Ref has a He 10% and a BV 20-30% lower than those of Mr. Ref.
So, putting together these values, the SFMs “expect the bacteria to human cell ratio to increase by about a third in women”(P).
 

Big guys, here we come.
In obese peoplethe [CV] increases with weight and plateaus at about 600 ml, i.e. about 50% higher than that of the standard man value(P), and the BD is similar to that of Mr. Ref.
As for the human cells count, well, obesity implicates an increase of adipose tissue, and this grows in two ways: the adipocytes stretch and get very big (hypertrophy), they grow in number (hyperplasia) (2). So, as for the hypertrophy, well dear visitor, you see for yourself that the cell count doesn’t change with this. As for the hyperplasia, there the fat cells number goes actually up. However, the SFMs have shown that adipocytes in Mr. Ref are a negligible 0.2% of the total human cells, so even if their number rises a bit that doesn’t impact on the final cell count in a sensible way.
Moreover