Sunday, November 11, 2012

Zombie Science

Katharine Harmon at Scientific American is fascinated by zombies ... in particular, animals whose parasites turn them into zombies. Here are three pieces from her ongoing series. (Sorry I'm late for Halloween with this post. Ah, well, zombies are always timely.)

Start by watching her 2-minute video on Scientific American's "Instant Egghead":

How Do Animals Become Zombies? Instant Egghead [Video]
Scientific American explains how animals--and possibly humans--can become real-life zombies
ZOMBIE WORLD: Parasites are responsible for many of the real-life zombies in the wild kingdom.Image: Instant Egghead
It may sound like something straight out of a horror movie, but many animals can come under the zombie-like control of parasites. So what about humans? Scientific American editor Katherine Harmon fills us in on the ghoulish side of Nature ...
[Note: The cat isn't our zombie here, in spite of the eyes. But house cats are the source a parasite, Toxoplasma gondii, which may infect 20% or so of us humans. T. gondii can change our hormone and dopamine levels, making us "more sociable, but also reckless".]


Then take a look at her overview article and slide show of zombie critters:

Zombie Creatures: What Happens When Animals Are Possessed by a Parasitic Puppet Master? [Slide Show]
From fungi to flies, some parasitic species have figured out how to control their host's behavior to get what they need. See what happens when bugs go really bad
ON THE DARK SIDE?: Some tiny organisms can make much larger animals do their dirty work for them. Find out how parasites can take control of bodies and minds.Image: STEVE YANOVIAK


And, finally, take a look at her most recent article on how being a zombie-ant fungus isn't without its dangers ... in the form of parasitic fungi of its own:
Undead-End: Fungus That Controls Zombie-Ants Has Own Fungal Stalker
A specialized parasite fungus can control ants' behavior. But that fungus also faces its own deadly, specialized parasites
ZOMBIE-ANT FUNGUS FEAST: New research is uncovering how zombie-ant fungus might control its hosts. But this parasite also has its own fungal threats.Image: Wikimedia Commons/David Hughes/
Maj-Britt Pontoppidan/PLoS ONE
An unsuspecting worker ant in Brazil's rainforest leaves its nest one morning. But instead of following the well-worn treetop paths of its nest mates, this ant stumbles along clumsily, walking in aimless circles, convulsing from time to time.
At high noon, as if programmed, the ant plunges its mandibles into the juicy main vein of a leaf and soon dies. Within days the stem of a fungus sprouts from the dead ant's head. After growing a stalk, the fungus casts spores to the ground below, where they can be picked up by other passing ants.
This strange cycle of undead life and death has been well documented and has earned the culprit the moniker: "zombie-ant" fungus—even in the scientific literature. But scientists are just learning the intricacies of this interplay between the Ophiocordyceps parasitic fungus and the Camponotini carpenter ants that it infects. Fossil evidence implies that this zombifying infection might have been happening for at least 48 million years. Recent research also suggests that different species of the fungus might specialize to infect different groups of ants across the globe. And close examination of the infected ant corpses has revealed an even newer level of spooky savagery—other fungi often parasitize the zombie-ant fungus parasite itself ...

Sunday, October 28, 2012

Eat Your Heart Out

Spoiler alert! This could spoil your appetite. Read and view on at your own risk.

(Donna, I'm sorry I didn't spot these before you left London. Though maybe a walk in the Richmond Deer Park was a better use of your limited free time.)

Spotted in time for Halloween by Ed Yong on The Guardian's website: "Herpes cupcakes! Smoker’s lung cake! The world’s most revolting (anatomically correct) cakes." And not just herpes: a full range of STD cupcakes (affectionately known as "STuD Muffins", I'm sure). Many more delights, including "a cup of flesh". All available (for a limited time only, ends today) at the cake shop at the Pathology Museum in London. All are edible. All depict some kind of morbidity.

As I understand it, you pay three and a half pounds, and you get what you get. Just like diseases in real life ... you don't get to choose, for the most part.

Some of these (as Ed notes) are delightfully repulsive. All would be loads of fun to have arrive on a plate at one's table. Here's one that probably won't put anyone off their feed. It probably fits the "eat your heart out" theme best. It's a fruit cake wrapped in marzipan ... with stitches.

I think my favorite are the Magotty Cupcakes. I'll put a photo at the bottom of this post so that the queasy among you can avoid it. But if you have the stomach, look at all 11 photos. They're really beautifully done. Happy Halloween!

Announcement from The Guardian website:

The world's most revolting cakes - in pictures

A repulsive cake shop is about to open at London's Pathology Museum graphically illustrating medical conditions and symptoms of disease in sugar, chocolate and sponge. Catch it while you can ...

 Eat Your Heart Out 2012 runs from 26–28 October at St Bart's Hospital, London

... and, as promised:

Tuesday, October 9, 2012

Two Stories about Birds by Ed Yong

I'm always on the lookout for bits about the physiology or anatomy of a bird that helps explain some unique behavior. Here are a couple of pieces by Ed Yong that fit that bill (sorry).

In this first story, Ed reports on some new thinking about why the New Caledonian crows are even better at innovative tool use than other corvids (crows, ravens, jays, etc.). You've probably seen some of the videos of New Caledonian crows using tools to get morsels of food, even using one tool to get another and using that second tool to get the food. (If you haven't seen the videos, Ed's piece has links to those, too.)

Smarter than the average crow, or just equipped with a face for fishing?

"Our intelligence clearly surpasses those of our primate relatives, even though other apes and monkeys also rank within the highest tiers of animal smarts. Likewise, the corvids – the group of birds that includes crows, ravens, rooks, magpies and jays – have very sophisticated brains for birds, but one species reputedly outclasses the rest. It’s the New Caledonian crow.

"Found in a Pacific island, this crow wields tools in a way that none of its relatives can match. It uses sticks to “fish” for grubs buried in dead wood, and can chosen the right tool for different jobs,combine tools together, and improvise from unusual materials. These abilities have fuelled the New Caledonian crow’s reputation as the top of the corvid class – an unusually intelligent member of an already intelligent family.

"But what if it just has the right face?" ...

And in a second story mentioned in the first one, Ed did a nice job of explaining why vultures, so sharp-sighted, are so very bad at avoiding the blades of the turbines in big wind farms.

Vulture blind spots lead to collisions with wind turbines

"Vultures have such large blind spots in their visual field that they cannot see objects directly in front of them when they fly. This discovery explains why vultures frequently collide with conspicuous structures such as wind turbines and power lines, despite having some of the sharpest eyes of any animal.

"This means that making wind turbines more conspicuous will do little to reduce collisions. 'You can paint them with bright stripes or hang things off them, but that won’t be effective,' says Graham Martin, an ornithologist at the University of Birmingham, UK, who led the study published this week in the journal Ibis. 'You’ve got to keep the birds and the turbines apart.'"

Reprogrammed Cells

This week, the Nobel Prize in Physiology or Medicine went to Gurdon and Yamanaka for work related to cloning and reprogramming somatic cells to pluripotency. New York Times: "Cloning and Stem Cell Work Earns Nobel".

Also this week, there were a couple of good reprogramming-related science stories:

Ed Yong wrote in The Scientist about success in reprogramming a type of brain cells (pericytes) into neurons in both mouse and human cell cultures ... without cell divisions.
Image  courtesy M. Karow et al., 2012
Growing New Neurons

"Making new neurons in the brain may not be as hard as once believed. Using just two proteins and without any cell divisions, scientists from Ludwig-Maximilians University Munich succeeded in reprogramming brain cells known as pericytes into neurons in both cultured cells from humans and mice."

And Katherine Harmon at Scientific American Blogs wrote about turning two types of mouse stem cells into viable mouse egg cells that were successfully fertilized and produced healthy baby mice.
Mouse pups from induced pluripotent
stem cell-derived eggs;
image courtesy of Katsuhiko Hayashi

Stem cells have been coaxed into creating everything from liver cells to beating heart tissue. Recently, these versatile cells were even used to make fertile mouse sperm. ... Now two types of stem cells have been turned into viable mouse egg cells that were fertilized and eventually yielded healthy baby mice.

Monday, October 1, 2012

Cryptobiotic Soil Crusts

Very informative post by Chris Clark on "Cyanobacteria, the desert soil, and you" at Pharyngula. I learned a lot. I'll include a bit of Clark's post below, but the whole thing isn't all that long ... and it's good.

Soil crust in Utah | J. Brew photo
"Cryptobiotic soil crusts, also referred to as cryptogamic soils, or just plain “crypto,” are pretty common in arid lands that haven’t been disturbed for a while. They’re alive, as indicated by the  suffix “biotic”: living communities of half a dozen different kinds of organisms: cyanobacteria, green and brown algae, fungi, lichens, mosses and liverworts. The “crypto” part means that when conditions are less than optimal, the organisms that make up the crust can go dormant, seeming to die off — “hiding” their life. Cryptobiotic.

"The crusts develop in places where there isn’t enough moisture to maintain a soil vegetative cover: no trees, no sod, no leaf litter, no humus. They usually start with filamentous cyanobacteria, which grow mats similar to fungal mycelia penetrating the top inch or three of soil. Cyanobacteria photosynthesize and many of them fix nitrogen, so  all they need to grow is water and a few soil nutrients. When it’s wet they extend their filamentous sheathes into the soil, which is exactly as sexy as it sounds, and then when the drought comes the cyanobacteria shrink back but the sheathes — made of polysaccharides, mainly — stay behind.

"Sometimes the crusts begin with green algae instead of cyanobacteria, often in places where the base soil is more acidic. Sometimes the two foundational phyla coexist, and sometimes a crust’s bedrock filament mat will shift from one to the other if soil pH shifts. Over time an entire swath of soil can become riddled with the filaments, and other organisms colonize them. Lichens are common crust inhabitants, as are free-living fungi, and the fungal hyphae from both add to the sturdiness of the crust. Mosses often join the cryptobiotic crust community, as do liverworts ..."

Sunday, September 30, 2012

Ben Goldacre

Ben Goldacre,
This week I've read a couple of pieces by Ben Goldacre, a doctor who writes a regular column called "Bad Science" in The Guardian and has written columns for The British Medical Journal, among other rags. The excerpt from his book Bad Pharma, called "The drugs don't work: a modern medical scandal" is good. Even more approachable, and somewhat broader in its target, is his TED video from this summer, "What doctors don't know about the drugs they prescribe".

In both the excerpt and the TED talk, he uses a case where he, a doctor probably more careful than most, was misled into prescribing a drug later shown to be not only ineffective, but harmful.

Two of my favorite science writers, Ed Yong and Carl Zimmer, got me reading Goldacre.

The Short List (29 Sept 2012)

Ed Yong's "Missing Links" list this week was short (nearer 60 than 100+), because he was traveling. My favorites from his list are all photos or short videos.

Ed Yong at Not Exactly Rocket Science

Some videos and photos (with and without text)
WOW! Watch from INSIDE a mussel’s shell, as a starfish shoves its stomach in and starts digesting [Rusten: fascinating in spite of the hyperdramatic Peter Coyote voice-over]
Hummingbirds are just as efficient when flying backwards or hovering forward. [Rusten: not exciting video, but amazing how utterly stable their flying is in different wind conditions]
A hummingbird skeleton  next to an elephant bird femur [Rusten: Wikipedia for elephant bird]
Drones. Crap. [Rusten: I liked the third video on tiny bot swarms. Hadn't seen the toy, armed drone helicopter.]

Friday, September 28, 2012

Friday Bits

Here are a couple of stories that appeared today, one semi-technical, the other not technical at all.

Ed Yong, "Thanks to one gene, this fly needs a cactus to escape Neverland"
Without feeding on the Senita cactus, a Sonoran desert fly can't transform from larva to adult.
Story teaser:
In North America’s Sonoran desert, there’s a fly that depends on a cactus. Thanks to a handful of changes in a gene called Neverland, Drosophila pachea can no longer make chemicals that it needs to grow and reproduce. These genetic changes represent the evolution of subservience – they inextricably bound the fly to the senita cactus, the only species with the substances the fly needs.

Robert Krulwich, "The Best College Prank Of The 1790s (With Bats, Poop & Grass)"
A simple story of a bit of eco-terrorism (ok, my anachronism, not his) over 200 years ago carefully designed to help introduce British gardeners to the wonders of guano. (With illustrations by Benjamin Arthur.)
Story teaser:
When William Buckland was a kid, an undergraduate at Oxford in the late 1790s — around the time George Washington had just finished being President — he pulled a prank that was so rude, so smart, and so biologically sophisticated for his day, I think he deserves a second crown, this one for Best Use of Grass Ever.

Tuesday, September 25, 2012

Why's this so good?: Banaszynski

[from Nieman Storyboard]
The whole "Why's this so good?" series at the Nieman Storyboard is a great resource for writers. But Jacqui Banaszynski's contribution, "No. 36: Alice Steinbach and one boy's vision", on Steinbach's Pulitzer Prize-winning 1985 piece, "A Boy of Unusual Vision" in the Baltimore Sun (PDF) is magnificent.

In fact, Banaszynski's whole reading list for her Intermediate Writing class, which you can find on the Nieman Storyboard's What's on your syllabus? page, would, with her annotations, be a great way to remind oneself of what writing can be.

Banaszynski won her own Pulitzer for Feature Writing in 1988 "for her moving series about the life and death of an AIDS victim in a rural farm community" in the St Paul Pioneer Press and Dispatch, titled "AIDS in the Heartland" (PDF).

The Pursuit of Balance

A nice little post at The Last Word on Nothing reminded me of the ever-changing cairn garden near one of the old lime kilns in the Pogonip near UCSC. The photo at left, taken in the fall, doesn't have enough contrast to do the cairn-builders justice. The cairns are always changing, sometimes incorporated into mazes, sometimes riding the limbs of surrounding trees as well as inhabiting the ground.

Follow the links in Nijhuis's post to more wonderful balanced stone sculptures. The beautiful, fanciful, and sometimes astounding ones by Adrian Gray were new to me.
I recommend going to his site and watching the two BBC videos of Gray working with stones on the beach. Goldsworthy, less a rock-balancing specialist, is always amazing.

Michelle Nijhuis, "The Pursuit of Balance"
Top of the story:

My neighborhood, as I've mentioned, is an interesting place: At our weekly potlucks, we speculate on everything from the number and sex of the next batch of goat kids (money's on two girls) to the efficacy of bourbon as mouthwash (not promising, sadly). Last week, a guest announced that he was on his way to a stone-balancing celebration in Flagstaff, Arizona. Was this a competition, we asked? No. Just a bunch of people stacking stones? Well, yes, but it's more fun than it sounds. Do you leave the stacks for other people to find? Yup.

"Just Google it," he finally said, giving us a beatific smile.

So I did, and found that yes, a bunch of people gathered in Flagstaff this past Sunday to stack stones. It seems to be habit-forming: this was the third international gathering of stone balancers, and balancers have even written an "Art Manifesto of Stone Balance" with ethical guidelines. (No glue, no bolts, no wires. Just gravity.) For some, such as artists Adrian Gray and Andy Goldsworthy, stone balancing is high art. For others, it's a meditative practice or just a prankish pastime ...

[Photo in Nijhuis's post from Flickr user jayul.]

Monday, September 24, 2012

Plants Are Cool, Too!

Botanist and biodiversity scientist Chris Martine at Bucknell University has begun an online project called "Plants Are Cool, Too!" to spur interest in plants as part of understanding biodiversity. The first two in a series of roughly 15-minute videos are out on YouTube (PlantsAreCoolToo) and highlighted in a little promo piece from Bucknell, "The dawn of adventure biology". In each video, Martine goes into the field with folks who are exploring the world of plants and their histories. They're well done and worth watching.

The first episode, on "The Pale Pitcher Plant", explores its ecological setting in the Southeastern US and dissects its "stomach" to show both how it collects the insect food it needs in a soil-nutrient-poor habitat and how other critters collaborate in breaking down those unfortunates the plant has trapped.

The second episode, on "Fossilized Forests", heads to Clarkia, Idaho, and a set of sediments where leaves were trapped 15 million years ago at the bottom of an inland lake created when lava flows blocked a river. The leaves aren't just fossils. They're the actual leaves that can still be lifted from the sediments. Their structure and color have been preserved, and folks are trying to recover their DNA.

Saturday, September 22, 2012

Mystery in the Fields

An intriguing three-part series "Mystery in the Fields" by Sasha Chavkin and Anna Barry-Jester reports that a mysterious and deadly form of chronic kidney disease is killing tens of thousands of young farm workers from Sri Lanka and India to Central America. There are clues that may link all of the cases, but researchers remain uncertain.

The impressive investigative project, part of it done in collaboration with PRI's The World, includes the three stories, helpful infographics, a photo slideshow, and two short videos by Anna Barry-Jester.

The stories as listed on the project website:

Ed Yong pointed out the first of these stories in his weekly "Missing Links" post at Not Exactly Rocket Science: "A mysterious kidney disease is killing young farm hands continents apart. Is there a connection?"

Corruption & Manipulation in a GM Story

Handling of a recent story about GM crops and health raised questions about science writing, integrity, and skepticism. Science journalists called out some of their colleagues and those who tried (and, in some cases, managed) to manipulate them. Lots of discussion of this case among science writers. Other folks may find the tale interesting as well.

First a link to Deborah Blum's post at Knight Science Journalism Tracker:

"A rancid, corrupt way to report about science"
Top of the story:
The quote in the headline on this post comes from Carl Zimmer's blog, The Loom, in a commentary on coverage of recent European study on possible health effects of eating GM crops. To give you the short version, the study authors appear to have practiced some very questionable science and some - and cynical - manipulation of the science media.

And then the story as outlined very briefly by Ed Yong in this week's "Missing Links" post at Not Exactly Rocket Science:

Lots of panicked headlines this week about GM-corn that supposedly led to tumours in lab rodents. The study’s incredibly weak – here’s an incisive analysis by SciCurious and another good one by Deborah Mackenzie at New Scientist. And here’s the real headline: reporters were prevented from even seeking outside opinions about the paper. Not only weak science but an absurd use of the embargo system.

Dew-Covered Insects (photos)

Thanks to Ed Yong for including a link to this wonderful set of photographs in his weekly "Missing Links" post at Not Exactly Rocket Science:

Macro Photographs of Dew-Covered Dragonflies and Other Insects by David Chambon

Here are just three images (reduced in size) to give you a taste of what you'll find on the site itself. And follow the links on the site to many more by Chambon and other photographers.



Thursday, September 20, 2012

The Birth of the New, The Rewiring of the Old

This is a nice update from Carl Zimmer at The Loom on a (now) 24-year-old experiment, explaining something "weird" that happened in one of the serial cultures 4 years ago: the appearance and then improvement of citrate-eating E. coli in one of the flasks. "World domination soon follows."

Carl Zimmer, "The Birth of the New, The Rewiring of the Old"

Top of the story:
The Birth of the New, The Rewiring of the Old
  In 1988, Richard Lenski, an evolutionary biologist now at Michigan State University, launched the longest running experiment on natural selection. It started with a single microbe–E. coli–which Lenski used to seed twelve genetically identical lines of bacteria. He placed each line in a separate flask, which he provisioned with a scant supply of glucose. The bacteria ate up the sugar in a few hours. The next day, he took a droplet of microbial broth from each flask and let it tumble into a new one, complete with a fresh supply of food. The bacteria boomed again, then starved again, and then were transferred again to a new home. Lenski and his colleagues have repeated this procedure every day for the past 24 years, rearing over 55,000 generations of bacteria.

I first reported on Lenski's experiment 12 years ago, and since then I've revisited it every few years. The bacteria have been evolving in all sorts of interesting ways, and Lenski has been able to reconstruct the history of that evolution in great detail, thanks to a frozen fossil record. Every 500 generations Lenski and his students sock away some bacteria from each flask ...