OF OCEAN, PLASTIC & BUGS: AN INTERVIEW

 OF OCEAN, PLASTIC & BUGS: AN INTERVIEW

 (in Eng?ish)

It’s a Wednesday, a big one, like a XXXL size one or so, but not a fatty Jabba the Hutt-big one, with all those soggy minutes and hours overflowing from its borders toward a much fitter Thursday [not Tuesday of course, since time, especially the soggy one, can’t overflow into the past, you know, otherwise the arrow of Miss Entropy (a dominatrix/nutritionist with a passion for basic physics, sloths, tattooed double chins and, of course, archery) gets all grumpy (Miss Entropy, not the arrow, which never gets grumpy because it’s very much into meditation, masters the art of self-control, aaand has a strong relationship with Mr. Valium) and you don’t want to mess with Miss Entropy and her arrow, especially when she’s all grumpy -well, maybe you can handle that if you’re a cat used to weird boxes full of guns (or of cyanide tablets and baskets of acids, or of hatching alien eggs, or of four very robust dudes who bet who would have eaten more lentils at lunch and the “it’s digestion time baby!” is going to begin…-]. No, put it simply, it’s a The Rock-big, a Ivan Drago-big, a Thor-big, a Steve Buscemi under steroids-big (… Ok, maybe not this unsettling) Wednesday.
And PiPs is floating like a feather of light on a blue sea. Under a blue sky. With its legs astride of a blue, slender, beautiful board (ok, not the same of the following pic, but, you know, whatever...).
Waiting for The wave.

 

[The pictures of the ocean (a) the surfboard (b) and of the plastic material (c) are adapted from Public Domain images by @sciencemug (source: Wikimedia Commons)]

But not far from PiPs there’s a wild bunch of blue (and of other colors too) pieces of plastic trash that, on the cry of “Nobody puts Baby in a corner!” (oddly enough, plastic rubbish near the shores collectively refer to themselves as “Baby” - nobody really knows why- while the plastic mush in deep water goes by the name of “Vida”) is ready to steal the perfect coming wave from PiPs, while, on the beach, some rubber masks, a couple of parachutes, a tanned heap of creased bucks and a pair of limping mustaches just passing by, seem to enjoy the show.
PiPs knows it’ll be a rough ride, above all ‘cause the plastic stuff can count on a legion of bacteria living on them, and those tiny little bugs can surely surf (and also make a really funny impression of Steve Buscemi under steroids, but that’s another story...)
So PiPs is all tense, focused and already starting to row with its skinny arms to jump on the back of that wave when a woman bravely approaching the surly school of plastic+bugs distracts it and make it lose the moment… (*)

Pips by SM

PiPs- Hey Miss, watch out, they’re nasty stuff! Who’re you anyway, and what are you doing here?

Ass. Prof. AMB

Ana Maria Barral- I am Ana Maria Barral, Assistant professor at National University in the balmy region of Southern California and I study the microbes that live on ocean plastic and, along with other life forms that live on it, make the so-called plastisphere. What I do here is hanging squares of different types of plastic that floats in the ocean. I am curious to know what kind of microbes attach to them when they are freshly out floating in the beach. We know quite a bit what kind of microbes live on them once they have disintegrated into tiny particles and are out in the ocean gyre. But we know little if the plastic floating close to the coast can carry any risks.

P- Cool, so you study the (coastal) plastiphere [which, by the way, I first thought to be the commercial name –the common one being “the in-real-need-of-a-hell-of-a-ton-of-wide-spectrum-antibiotics-before-they-eventually-stop-working round thingy”- of a super fancy biotech XXI century version of the old disco ball, with, instead of all those banal little mirrors so âgé, a whole load of multi-bioluminescent bugs flashing in sync with the music (hey, I should patent it, maybe I’ll get rich by that and finally realize my dream to retire in a very exclusive url of the dominion “.whateverudreamcomestrueinheredudeevenifuarebutareallystupidpostwithoveractivearmpits”…)].
 

The plastiphere according to PiPs (by @sciencemug)

 [The picture of the disco ball is a Public Domain image adapted by @sciencemug (source: Wikimedia Commons)]

Anyway, Prof. Barral, why do you study precisely bacteria and their near shore floating plastic shacks? I mean, why don’t you study, I dunno, how come there’re sea stars but not sea black-holes; or why betters don’t ever wager on seahorses; or who, among bacteria, mosquitoes, cockroaches, rats and drivers who don’t use blinkers, is gonna inherit the world when you humans are gone; or whether, given all the plastic floating on the seas of the world, all the people undergoing plastic surgery risk, afterwards, to go to bed and then to suddenly awaken in the middle of the You-Name-It Ocean with only a pair of leaking water wings around their arms and with a splintered mirror floating aside them on which it is written, with some cheap lipstick, “welcome home”?
And, above all, professor, how come you ended up studying precisely bacteria and their near shore floating plastic shacks? Did you lose/win a bet (on a rigged seahorse race, maybe?)

AMB- I came from the school that bacteria were bad and caused diseases, so when the whole idea of microbes living in us and on us, and being so important to shape our health came out I was amazed. A great book that just came out on this is Ed Yong’s “I contain multitudes“, I really recommend it. So I am curious about microbes in general and how they impact our lives. On the other hand I love the ocean, I live close to the ocean and I feel very strongly about plstic pollution. So when this project was presented to me I jumped on the opportunity.
As for the how

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

(PART 1)

(PART2)

  

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

by @sciencemug

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.

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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 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

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 people “the [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

BACTERIA vs HUMAN CELLS: 1 to 1 (FINAL) PT1/3

by @sciencemug

The ratio between bacteria and human cells in the human body is 1 to 1 and not, as commonly thought till now, 10 to 1.
The updated estimate has been provided by three scientists from Israeli and Canadian universities in a study published on the science journal Cell.
(A pre-print version of the paper is avaiable also on bioRxiv, a free online archive for unpublished research papers in the field of life sciences).

PART 1/3

Part 2
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Ooooh, hallo dear English speaking-reading-hearing visitor, welcome back to me, @sciencemug, the blog/podcast/twitter account which tells science stories, masters the ancient art of napping en plein air, breeds race sloths (for adrenaline addicted betters who like to stretch as much as possible the adrenaline-producing suspense of the races) aaand which sometimes (but not this time) talks to you thanks to the voice that is kidnapped, via a voodoo-wireless trick, from a veeery very very dumb dude.
Aaand which does all of this in Eng?ish, a language that is to proper English what a sneeze is to an authentic expression of free will and a student loan is to a cascade of donuts+pizza which plunges into a pool full of prosecco, gold and diamonds (and beautiful shoes if you’re a lady) and that is surrounded by sexy half naked women/men holding signs that say: “all of this is for you [YOUR NAME], for free. Come and get it!”

Today I’m gonna tell you the story of the death of a semi-scientific almost urban legend about numbers, bacteria and human cells!

by @sciencemug

Soo, the story goes like this: a biology student, Ron Sender, a medical doctor, Shai Fuchs and a biology professor, Ron Milo (aka the SFMs) join their efforts to debunk the myth that, in the human body, bacteria outnumber human cells by 10 to 1.
Well, in the human body… Let’s say in the human body of an healthy adult male between 20-30 years of age, weighing 70 kg (oooooh for your brain’s sake, get over all this “I don’t know the Metric System-SI gnè gnè gnè”… Look, it’s more rational, efficient and simple than yours, besides being used worldwide. Stop whining and learn it!) and 170 cm in height that scientists use as the reference human being (aka Mr. Ref) since 1975 [when The International Commission on Radiological  Protection (alias ICRP) publishes the 480 pages long “Report of the Task Group on Reference Man, ICRP Publication 23” which addresses the need to define a reference individual for the studies regarding humans and the risks and consequences of radiations exposition (1)].
 
Ok, let’s say that it’s true that a looot of bacteria (belonging to more than “10,000 microbial species (2))” -at least in the healthy Western population- live in and on you, and that they “inhabit just about every part of the human body (2)” (skin, up the nose, mouth, guts and so on). But the news is that the number of these microorganisms, the SFMs say, is smaller than thought.
 
First of all the science trio gets to the roots of the 10:1 myth, digging deep into the science literature and finding out that all the recent papers that report the 10 to 1 ratio refer to just one study published in 1977 by Savage (aaand good luck if you want to read it for free… By the way, in case you find it, please send me a copy of it).
Now, this study, the SFMs say, is a solid piece of science work, but, although “referenced over 1000 times in the literature often in the context of the estimate for the vast overabundance of bacteria over human cells” (Sanders et al, 2016; (P)) its 10 to 1 estimate is just a rough calculation. Above all, Sender and lab coat pals precise, it isn’t meant at all to become “the cornerstone of an entire field” (P), being this one the human microbiome field, namely the research area which sees human beings as ecosystems formed by human cells and a plethora of other life forms, mostly bacteria (i.e. the microbiota).
Moreover, our three science myth-busters add, ironically the very same 1977 Savage study refers to another paper by Luckey dated 1972 (again, good luck if you wanna read it) for the total amount of bacteria harbored by humans (FIG1).
 

The chain of citations (adaptation of a figure of Sander et al, 2016 paper by @sciencemug)

 FIG 1

This 1972 Luckey’s paper says that you human beings live with 10¹⁴ bacteria, assuming that your alimentary tract have a capacity of about 1liter (and thus of roughly 1kilogram) and that it contain 10¹¹ bugs per gram (gram: see above, you “gné gné gné”) (FIG2).
 

by @sciencemug

[Hamlet's image is a Public Domain pic adapted by @sciencemug (source: Wikimedia Commons)]

FIG2

Soooo, dear listener, being you the smart ecosystem you are, I guess you’re probably wondering why the ‘70s science guys and all the science community after ‘em focus only on the bacterial population of the alimentary tract to determine how many microbes inhabit your whole body, right? I mean, I can feel you thinking “hey, wait a min dude – sorry, pal, but technically I’m not a dude (and also non technically, I’ve to say)…- I’m much more than my mouth stomach and bowels, c’mon, I’ve a couple of lungs (just to mention something) eyes, a lot of skin, those funny thingies I can’t figure out why be there, yeah, those… I mean, really, I’ve got a lot of stuff of me other than mouth stomach and bowels!”.
Aaand yeah, you’re right dear visitor, you’re the proud owner of lungs, eyes, skin and the non-bowel rest, but, science at hand, the ‘70s lab guys were right to focus on the alimentary tract to quantify the microbiota members of the human body, and even our science myth-busters SFMs back ‘em up on this. Well, more or less.
Actually our science trio specifies that, of the whole human alimentary tract, the relevant part is only