Microscopic-organisms

Sporozoites of the parasite Cryptosporidium parvum emerging from their oocyst to infect gastrointestinal epithelial cells.

Cryptosporidium, commonly known by the comic book supervillian name “Crypto,” is transmitted by ingesting water or food contaminated with Crypto oocysts. Once ingested, the oocyte ruptures, and the sporozoites contained within infect the gut of their new host, causing watery diarrhea. 

Though outbreaks occasionally occur in the developed world, few infected in those outbreaks die from Crypto. However, in the developing world, some of those infected with Crypto develop chronic disease and die, particularly small, malnourished children.

For more on Crypto and how scientists are tackling this tricky parasite, check out this article on NPR’s All Things Considered about the work being done by the Striepen lab at the University of Georgia Center for Tropical and Emerging Global Diseases.

Image courtesy Boris Striepen and Muthgapatti Kandasamy, University of Georgia Center for Tropical and Emerging Global Diseases

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First Animal to Survive in Space

Tardigrades or “Water Bears” are the only creatures that can survive the extreme conditions in the vacuum of outer space.

This dude might have discovered a new species of tardigrade too. :0

eartharchives.org
Tardigrades are one giant head
No one would argue that tardigrades got stiffed in the weirdness department. These teensy animals, also called water bears, look roly-poly under a microscope. Less than a millimeter long, they can survive extremes of heat, cold, pressure, and radiation that are deadly to most other lifeforms. Under duress, a tardigrade may curl itself into a dried-up ball called a tun, then stay in a state of suspended animation for years before returning to life. Now, researchers poring over the animal’s genes have found another oddity. The tardigrade, they say, is essentially one giant head.

I think this is the prettiest chart on the internet. I also find it one of the most useful.

There are three things I find interesting about it.  The first is that it shows you the major paradigm shifts in the evolution of life (prokaryotes, then eukaryotes, then multicellular life, etc.) and that they occur closer and closer together.  

The second is that it shows that more than half of the history of life is dominated by creatures less than a millimeter across.  That means that if there’s extraterrestrial biological life, it’s probably like that and not like us.  

The third thing is that it shows the occurrences of “snowball earths” - periods in Earth’s history when life drastically changed the climate.  We need to act quickly to stop and reverse global warming.  But I find it interesting that there have been times throughout geologic history when life has undermined itself just by going about its business.  The biosphere is not a smoothly functioning whole a la the Gaia hypothesis.  The world is better modeled by the Medea hypothesis.  We’re not the first creatures living in an unsustainable relationship with their environment.

Four (okay there’s a fourth thing), the whole late heavy bombardment thing is interesting.  Was there life before it that got wiped out?  How long after it did life start?  We don’t know.  (The graph is wrong to say with certainty that life started 4000 Ma.  We don’t know that.)  We don’t know how life started.  We barely know what the conditions of life are.  Hell, we don’t even know what life is.  

There are a lot of puzzles in this chart.  I think that’s why I like it so much.

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Look at this terrifying microscopic monster omfg.

Incredibly Small: Best Microscope Photos of the Year

Every year for nearly four decades, Nikon has received hundreds of entries in its Small World microscope photography contest. Every year, the images are more amazing, and this year’s winners – selected from nearly 2,000 submissions – are undoubtedly the best yet.

Super-close-ups of garlic, snail fossils, stinging nettle, bat embryos, bone cancer and a ladybug are among the top images this year. The first place winner (above) shows the blood-brain barrier in a living zebrafish embryo, which Nikon believes is the first image ever to show the formation of this barrier in a live animal

Read more…

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Comment Response: First Animal to Survive in Space

Science? Religion? Tardigrades? 42? Our piece received so much feedback that we had to ask Mike to respond to some of the most interesting, bizarre, and controversial comments.

He answers some funny ones too. xD

Soil is not just a bunch of little rocks, a spoonful of healthy soil contains many millions of beneficial microscopic organisms of various kinds that include beneficial species of bacteria, fungi, nematodes and protozoa that never cause disease or become pests. These are helpful species that perform vital “functions” in the root zone that can bring real benefits to your plants. Bacteria and protozoa are great micro-organisms in your soil. Bacteria break down dead organic matter. Certain types fix nitrogen - converting nitrogen from the air into a form plants can use.

Just keep swimming...

With the recent release of Pixar’s Finding Dory, many PSAs have been shared on social media to inform the masses NOT to keep a “Dory” fish, or blue tang (Paracanthurus hepatus), in a saltwater aquarium at home, citing a number of reasons.



What a beautiful fish this is. Picture credit.


Since “Dory” has never been successfully bred in captivity, blue tangs and many other types of marine ornamental fish are removed from coral reefs for the saltwater aquarium industry. Unsustainable removal of the many colourful reef fish as ornamental fish, especially at a time of global mass coral bleaching due to high sea surface temperatures from the El Nino Southern Oscillation phenomenon, will further inhibit the recovery of a coral reef ecosystem, which already does not look too good for the majority of the bleached corals.



Colourful reef fishes. Picture credit.


Bleached corals are corals that have lost their pigment, 98% of which came from microscopic symbiotic organisms, commonly known as zooxanthellae. Under stress like rising sea surface temperatures, corals can expel these very important symbiotic organisms as the zooxanthellae have been damaged by high water temperatures. If conditions return to normal on time (prolonged stressors will cause these corals to completely die), corals can then “catch” free-swimming, healthy zooxanthellae from the surrounding water to gain its vibrant colours again.



The mass bleaching seen in the most popular dive site at Pulau Payar Marine Park taken recently. 


So how do these fish help out when corals are recovering from a bleaching event? Many of these beautiful reef fish can feed on growing macroalgae (seaweed) which can tower and overshade corals if not “trimmed”. This is a vital process in a coral reef ecosystem because it allows for sunlight to reach the corals for the zooxanthellae to carry out photosynthesis. The food created by the zooxanthellae from photosynthesis are then shared with the corals and is the main source of energy for the corals. So even if the corals do get to recover from a bleaching event, they may still do badly if there are too many tall macroalgae growing on the corals.

Although irresponsible methods of ornamental fish are not the main cause of coral reef ecosystems failing (main causes are habitat destruction, overfishing for food, and climate change), their unsustainable removal exacerbates these negative impacts.

Therefore, let us try our very best to help these coral reefs thrive again by making informed decisions. 


Jonathan