Stories tagged Life Science

Sep
22
2011

Achatina fulica: the giant African land snail.
Achatina fulica: the giant African land snail.Courtesy motnworb
We’ve seen it before. Through the years the human race has had to endure attacks by giant creatures of all sorts.

First, a humongous lizard larger than any known dinosaur crushes Tokyo and incinerates the rubble with his bad breath. Then super-sized spiders from another dimension terrorize northern Wisconsin only to be reduced to sludge by clever scientists. Later, gigantic ants run amok in New Mexico destroying property and people until the US Air Force, Navy, AND the Army are called in to destroy them. And now on top of all that, there are reports that large numbers of giant snails are terrorizing south Florida. When will this madness end?!

Of course the first three examples are pure fiction. Godzilla never really existed, spiders from another dimension can’t enter ours through wormholes, and the idea of gigantic ants is just stupid. But unfortunately the giant African snails infesting south Florida are all too real. And as you can see by the accompanying photo these suckers are huge. Some can grow up to 15 inches in length and weigh two pounds! Think of the slime trail!

These giant African land snails (Achatina fulica) are illegal in many countries including the US, but it appears some have gotten in. The snails are sometimes used in a traditional African religious ceremony where practitioners ingest their slimy gastropod juices (goodness gracious!) and word is that a woman from Africa may have smuggled them through customs under her dress in 2010. Okay.

Like many invertebrates, giant snails are hermaphroditic, possessing both male and female reproductive organs. After mating each partner can produce offspring, as many as 200 at a time, and up to 1200 a year! These things are worse than rabbits… and as big as rabbits, too.

Look at the photo again. Whoa!

Two sisters in a residential neighborhood in Miami-Dade County discovered some of the snails in their yard and showed one to a fruit fly inspector who then alerted officials at Florida’s Department of Agriculture. The agency didn’t want to bother the armed forces so they canvassed about a square mile surrounding the sisters’ house on their own and hand removed all the giant African land snails they could find. A few days later they scoured the area again and found even more.

The problem with this particular species of giant snail is that it likes to eat about 500 different types of plants, and can sometimes carry a strain of non-fatal meningitis that’s contagious to humans through contact with the gastropod (like drinking its juices – duh), so eradication of A. fulica is deemed a high priority.

This isn’t the first time Florida has been invaded by giant African land snails. In 1966, the state spent about a million bucks getting rid of 18,000 of them.

SOURCES and LINKS
Story on abcnews.com
Miami Herald story
Online News website story
More photos of giant snails
More about giant African land snails

Aug
22
2011

Happy, happy, joy, joy!: A new study touts the positive effects of Personal Activity Interventions (PAIs).
Happy, happy, joy, joy!: A new study touts the positive effects of Personal Activity Interventions (PAIs).Courtesy Mark Ryan

"Got no checkbooks, got no banks,
Still, I'd like to express my thanks.
I've got the sun in the morning
And the moon at night.“

Words and music by Irving Berlin

The simple sentiments found in the lyrics of Irving Berlin’s “I’ve Got the Sun in the Morning and the Moon at Night” are at the core of a self-administered therapy technique that has proven helpful for folks who suffer from depression.

Researchers from the University of California-Riverside and Duke University in North Carolina recently reviewed medical literature regarding a technique known as Personal Activity Interventions (PAIs). PAIs involve using simple, self-administered techniques such as counting your blessings, acting kindly towards others, showing gratitude (i.e. writing thank you notes), and meditating positive feelings about others, among other things, and according to the study, showed significant positive results for people suffering from depression. The affliction can be disabilitating, and there are a lot of sufferers out there, something like 100 million people worldwide.

Depression, according the study, is “a heterogeneous condition with molecular and biochemical origins that are still not fully understood.” It goes on to say that the World Health Organization (WHO) estimates that less than 10 percent of those who do suffer get treated for it. The reasons for lack of proper treatment range from economic distress to stigma to the lack of medical resources and providers. When resources are at hand, conventional treatments usually involve patients talking with a therapist or taking pharmaceuticals, or both. But the authors note that the current drug therapy is not quite up to par.

"Response rates to a single antidepressant are generally considered to be 60%–70%, with over 80% of the drug effect accounted for by placebo effects. Even with this relatively high percentage of ‘‘responders’’ to drug treatment, initial pharmacotherapy produces remission in only 30%– 40% of the depressed population.“

Harnessing the Power of Positive Thoughts and Emotions to Treat Depression

This brings to mind how some new television commercials are touting taking an additional drug that may be helpful if your regular anti-depressant isn’t quite doing its job. They urge you to ask your doctor if the advertised drug is right for you. So, essentially what the drug companies are saying is if one of our drugs isn’t doing it for you, just take more. What happens when the new drug doesn’t work? I think you’re asking for trouble going down that road.

But I like this idea of using PAIs. The study claims the improvement rate from their use is remarkable and longer lasting than traditional talk and drug therapies. What’s particularly interesting is that PAIs carry almost none of the obstacles involved with conventional treatment methods. Often when a patient is in the depths of depression it can be difficult for them to find the motivation to seek out traditional therapies. The steps involved in finding a therapist, setting up an appointment, getting themselves to the therapist’s office, can appear daunting when struggling with depression. Many current anti-depressants can take weeks to become effective, or can produce unwanted side effects, or even carry a stigma of embarrassment for some patients. As mentioned before, the lack of economic resources or treatment accessibility can also block a patient from getting treatment. But doing Personal Activity Interventions involve none of those obstacles, and since PAIs are self-administered, any successful results can empower a user and bolster his or hers self-esteem. The method can also give an additional sense of accomplishment because the therapy doesn’t involve the aid of outside factors such as therapists and drugs. The resulting elevated mood can raise productivity and creativity levels, and enhance personal relationships.

So, empirically, PAIs seem to be effective in reversing a downward mood spiral. I figure anything that proves helpful in battling depression can’t be bad, and that includes traditional talk and drug therapies. It’s interesting to note that besides in Irving Berlin’s song some of the techniques found in the PAIs method such as expressing gratitude, wishing others well, and meditating can also be found in many 12-step recovery programs, such as Alcoholics Anonymous.

The review appeared in the Journal of Alternative and Complementary Medicine and is available free online to download here.

Eurekalert
More about depression

Aug
06
2011

Archaeopteryx (Thermopolis specimen): Has the iconic transitional fossil had its feathers ruffled by a recent discovery? Not really.
Archaeopteryx (Thermopolis specimen): Has the iconic transitional fossil had its feathers ruffled by a recent discovery? Not really.Courtesy Mark Ryan
China has been producing some remarkable and groundbreaking dinosaur fossils in recent years that have caused paleontologists to reconsider long-held views. A recently described feathered dinosaur is no different. Xiaotingia zhengi, discovered in the Jurassic shales of the Liaoning Province, has been in the news lately because it supposedly knocked the well-known, so-called proto-bird Archaeopteryx from its perch as the earliest bird.

The study by paleontologist Xu Xing and his colleagues from the Chinese Academy of Sciences in Beijing appears in Nature. Their research, it seems, has determined that Xiaotingia and Archaeopteryx share many features that make the two of them more bird-like dinosaurs than dinosaur-like birds. Do you see the difference there? I guess I do. Anyway, essentially what it means is that Archaeopteryx has been pushed back a little and is just a bit more distantly related to birds than previously thought. The classification places both Xiaotingia and Archaeopteryx in with avian-like carnivorous dinosaurs such as deinonychosaurs, dromaeosaurids, and troodontids. The recent spate of fossils coming out of China can’t help but alter some our old views of the middle to late Jurassic fauna. Many dinosaurs (including non-avian ones) living during that time were equipped with bird-like features: e. g. long arms, feathers, wishbones, etc. They were all over the place.

But all you diehards out there in the Archaeopteryx-is-a-bird camp need not despair just yet. Dr. Xu himself admits that some of the conclusions in the study are based on pretty weak evidence. Archaeopteryx continues to rank as an exceptional transitional fossil (along with Xiaotingia). Its place in the transition has just shifted slightly, that’s all. Further studies and new fossils will no-doubt shake up the branches of the avian family tree again.

References:
Story at Pharyngula
New York Times story

Jul
12
2011

The Route: We will be entering at entry point #16 Moose/Portage River and exiting at entry point #43 Bower Trout Lake.   The route was designed to expose us to a wide range of use areas within the BWCAW.
The Route: We will be entering at entry point #16 Moose/Portage River and exiting at entry point #43 Bower Trout Lake. The route was designed to expose us to a wide range of use areas within the BWCAW.Courtesy The Great Pack Out
In honor of National Public Lands Day (9/24/2011), my brother and I are going to spend two weeks paddling over 120 miles across the Boundary Waters Canoe Area Wilderness (BWCAW) documenting and collecting all the trash that we find. My brother and I have been paddling in the BWCAW for 23 years and over the last few years have noticed an increase in the amount of garbage we encounter on portages and at campsites. So we started wondering how much trash is actually out there. Is it isolated to the highly used areas near the edges or endemic to the entire BWCAW? In doing some research on the wilderness we discovered that the BWCAW comprises less then 1% of the U.S. National Wilderness Areas yet receives greater then 10% of the recreational activity. What effect does this recreational density have on the quality of the wilderness?

No one really knows. Studies have not been completed. That’s why my brother and I have decided to check it out. We are going to paddle the BWCAW from west to east documenting, collecting, and packing out all the trash we encounter along the way. We will inventory and catalog everything we find and create trash density maps to aid wilderness resource managers focus education and clean up efforts. Who knows, maybe we will inspire others to clean up the BWCAW next year on National Public Lands Day and every day.

Check out our blog for updates and we'll check in following the trip to report our findings.

Jul
11
2011

Have you ever wanted to get involved in scientific research, but figured you weren't qualified? It turns out that scientists need help from people like you all over the world. Citizen science has been a popular pastime for nerdy types for quite a while, and now, online projects are connecting citizen scientists using social media.

Spiral Galaxy: Citizen scientists sort through images like this one from the Hubble Space Telescope at Galaxy Zoo.
Spiral Galaxy: Citizen scientists sort through images like this one from the Hubble Space Telescope at Galaxy Zoo.Courtesy NASA

What is citizen science, you ask? It takes many forms, but the ultimate goal is for normal folks like you and me to lend our time and abilities to scientists--to collect data, tag birds, photograph species--the list goes on. Amateurs help scientists by extending their observational reach--a network of 40 citizens all over the country can make more observations than 2-3 scientists in one location. They also help scientists by performing simple tasks that can be time-consuming but don't ultimately require specialized training.

Whether you're interested in plants, animals, climate, weather, pollution, or astronomy, there are plenty of ways to get involved--Cornell Lab of Ornithology's Citizen Science Central is a clearinghouse of citizen science projects. Some examples include:

You can even use your computer to model climate change. In these projects, it's important to follow directions from the scientists, to make sure your data and other contributions are usable. But no matter how you get involved, it's a great way to help develop a better understanding of the world around us, which helps pave the way for a better future.

May
23
2011

Tibicen linnei: An annual cicada
Tibicen linnei: An annual cicadaCourtesy Bruce Marlin (via Wikipedia Creative Commons)
Summer is heading our way and soon the familiar buzzing of cicadas will fill the air. But for some, particularly in the southern and eastern United States, the buzz will become a loud symphony of sound. That's because, this year, the Great Southern Brood will (actually already has in some places) reappear and millions of the insects will soon be crawling out of the ground to overwhelm us with their vast numbers and cacaphonic chorus.

Relax. Last weekend's rapture was a bust (or was it?), and there’s nothing to worry about in the biblical sense. It’s merely the latest appearance of Magicicada neotredecim and M. tredecim, two closely related species of cicada that show up every 13 years in the United States to fill the treetops with their buzzing song.

The most common genus of cicadas in the US is Tibicen and unlike Magicicada, cicadas in the genus Tibicen appear annually, not periodically. After a 2-3 year stint as nymphs, Tibecen cicadas emerge into their adult stage. The full-grown insect measures about 1-2 inches in length with long translucent wings and distinctive green, brown, and black markings on the middle of its body. Generations overlap so they show up every year and can be heard in many areas, including Minnesota, during the hot and steamy Dog Days of summer buzzing to high heaven. It’s that shrill, grating noise that builds in the air and sounds like someone is cutting up cement blocks with a chainsaw. As deafening as it can be, I like the sound, in much the same way I like the smell of rotting leaves in the fall, it triggers memories.

But I’m not sure how I’d feel about Tibicen's cyclical cousins - those belonging to the Magicada genus - that show up all at once in mass periodical emergences and put on huge choruses of buzzing. There are seven species that do this in the US, three in 13-year cycles, and four in 17-year cycles. Periodical cicadas are categorized into broods numbered in Roman numerals from I to XXX. The thirteen-year cycles occupy XVIII–XXX; seventeen-year cycles number I–XVII. Only about 15 broods are still recognized. There are still only seven cyclical species but some species emerge happen at different times in different regions, hence the number of broods. This year it will be a 13-year cycle called Brood XIX , and it is the largest of the 13-year cycles in terms of geography.

The numbers involved in a periodical swarm are huge but, as Vanderbilt biologist Patrick Abbot explains, the vast numbers increase the possibility of available mates and serve as a way to overwhelm the cicadas many predators, which include birds, snakes, turtles, spiders and wasps, and even fungi. It’s interesting that the periodical emergences have evolved into separate prime number cycles. The reason is probably to reduce competition between broods.

“Say you have two populations, one which emerges every five years and one which emerges every 10 years. Then they would emerge simultaneously every 10 years," Abbot said. "Whereas the period between simultaneous emergences between populations with 13- and 17-year cycles is 221 years."

Occasionally, two cyclical broods have been known to emerge simultaneously but usually the overlap is minimal. For example two 13-year broods rising at the same time but in adjacent regions.

During a brood’s synchronized emergence the number of individuals can be daunting. Some emergences have been estimated to contain something like 1.5 million cicadas per acre of land. That amounts to 800 tons (!) of biomass busily buzzing within a square mile of forest. Think of that!

But despite the huge numbers involved in a cyclical emergence, cicadas are pretty harmless, and don’t voraciously eat up crops like locusts do, nor do they sting or bite. The most damage done is by females when they make “v”-shaped slits in the bark of a twig to lay their eggs (I suppose this could feel like a sting if she mistakes your arm for a tree branch). But, come on, even this is nothing compared to a plague of locusts wiping out the summer corn crop.

The word cicada is Latin and means “buzzer” Very apropos, don’t you think? The males of the species spend a lot of time trying to get the attention of female cicadas by vibrating a membrane on their exoskeleton called tymbals. Each time the muscles contract or relax the tymbals they produce a click. Portions of the exoskeleton such as the abdomen or thorax help amplify the sound. The rapid vibration causes a shrill and (possibly annoying) buzzing, and each of the world’s estimated 2500-3000 species has its own distinct sound. The females, by comparison, make a rather boring click with their wings to attract males (I suppose the male cicadas don’t think it boring). You can replicate the female clicking by snapping your fingers in rapid succession a couple times.

When periodical cicada eggs hatch the nymphs drop down and burrow deep into the ground where they spend most of their lives sustaining themselves for several years ingesting fluids from tree roots and developing through five juvenile stages. Scientists suspect soil temperature triggers the emergence. When it reaches 64 degrees F., the nymphs head for the surface. It seems the likely catalyst since emergences in warmer, southern regions take place sooner than those farther north. Whatever the case, when they do emerge, the nymphs crawl up and attach themselves to nearby vegetation where they eventually molt out of their skins. They don’t begin adult activities until after their exoskeletons harden. So for the first 4 to 8 days after molting, they pass through a stage called teneral (meaning soft and tender) before the exoskeleton is complete. The adult stage of a cicada lasts anywhere from a couple weeks to a few months. Very short in comparison to their other life stages.

People eat cicadas in several areas of the world. And the females are meatier and more desired. I suppose the insect is a good source of protein but – there’s no way I’m ever doing that - I’d never eat one. Maybe I shouldn’t say “never”. Some Native American tribes supposedly survived times of famine by eating cicadas.

If you live in or are visiting an area that is or will soon be overrun by an invasion of the Great Southern Brood, rather than cowering in a corner and wailing and gnashing your teeth, head outside, go for a walk, and take in a symphony of cicada songs. While you’re out there enjoying the summer day, you can get even more involved by trying some of these neat cicada experiments. It will take your mind off the fact that you’re surrounded by 800 tons of buzzing biomass.

SOURCES and LINKS

Cicada Central
Magicicada.org
Vanderbilt release
Cicada Mania page

May
14
2011

A male in New Mexico has been confirmed as being infected with the bubonic plague; and has earned the distinction of being the first person to get it this year. The Black Plague, a flea-borne disease, has never gone completely away and individuals in some remote areas are at some risk for catching it. There are about a dozen cases in the United States from bubonic plague annually.

Plague patient admitted to New Mexico hospital

The first person in the United States this year to have the bubonic plague is a 58 year old man from New Mexico. Who this man is has not been released yet. Time states it is being kept secret for now. There are certain plague symptoms. The male had them all. He was admitted with a fever, abdominal and groin pain along with painfully swollen lymph nodes. In plague patients, lymph glands swell to the point where they're visible, which in the Middle Ages came to be referred to as a "bubo," hence the name "bubonic plague.". Wikipedia explained that "bubo" means lymph nodes. It is ancient Greek.

No need to bring out the dead

On average, there are 13 bubonic plague cases annually while 1 to 40 are typically reported, the CDC states. Without treatment, 50 to 90 percent of cases will end in death. That number drops to 15 percent when treated properly. In 2003, the World Health Organization recorded 2,118 cases in nine nations and 182 deaths. Of those cases, 98.7 percent were in Africa, as were 98.9 percent of the deaths. Most cases in the United States occur in New Mexico, according to the Miami New Times. In 2009, there were 6 New Mexico plague cases. Since 1949, there have been 262 cases total. Until the middle of the 20th century, small plague outbreaks were common. The Los Angele Times states that only then did it start to become uncommon. Outbreaks were noted in San Francisco from 1900 to 1908, and epidemics occurred in Oakland in 1919 and LA from 1924 to 1925. The plague was a real issue in 1924 in LA. There were 37 people killed from it.

Comes from fleas

"The bubonic plague, or the Black Plague or Black Death, is caused by a bacteria carried by fleas called Yersinis Pestris. Plague-infected fleas spread it by feeding on small rodents for instance prairie dogs, rats, chipmunks and ground squirrels. Individuals with pets or rodents near can have the fleas on the animal. Then, the flea can jump to the human. The disease is caused when people are bitten by fleas carrying the bacteria. There is a lot of risk in the Southwest. This is where it is the greatest. New Mexico is home to half of all cases, but other cases have occurred in Arizona, California, Nevada and Oregon. Unless the disease becomes pneumonic plague in the lungs, it is non-infections in individuals. It can help to have antibiotics. This has to be within the first 24 hrs of symptoms though.“

Articles cited

Time
Miami New Times
Centers for Disease Control
World Health Organization
Bubonic plague on Wikipedia
Los Angeles Times

Apr
26
2011

Dinosaur art: One of the many dinosaur statues created during the Science Museum of Minnesota's Diggin' Dinosaurs competition in 2007. This one resided near the Lake Harriet bandshell in Minneapolis, MN.
Dinosaur art: One of the many dinosaur statues created during the Science Museum of Minnesota's Diggin' Dinosaurs competition in 2007. This one resided near the Lake Harriet bandshell in Minneapolis, MN.Courtesy Mark Ryan
Over at the Smithsonian's Dinosaur Tracking blog, dinosaur maniac Brian Switek has a cool article about a little girl named Annabelle who had visited New York's Museum of Modern Art (MoMA) recently and was miffed that it didn't contain any dinosaurs ("You call yourself a museum", she spewed on a comment card). Switek covers the usual early and well-known dinosaur artists such as Benjamin Waterhouse Hawkins, Charles Knight, and Rudolph Zallinger and also mentions not only some of today's science illustrators, but also a guy I found really interesting named Allan McCollum who makes some very unusual dinosaur artwork using bone casts and other methods. He creates the dinosaur art for art's sake rather than scientific Occasionally, I've come across other dino art for art's sake, even here in the Twin Cities. Some readers will remember a few years back when the Science Museum of Minnesota held a competition called Diggin' Dinos that involved local artists painting several colorful dinosaur statues in celebration of the museum's 100th anniversary. There was a ton of dinosaur art created then, and some of the statues can still be found around the Twin Cities. Maybe the MoMA would be interested in exhibiting some of those, so next time poor Annabelle visits there she won't be disappointed.

Why the MoMA Should Have Dinosaurs

Apr
22
2011

Meat: Is it your good friend, or old enemy? Tell us.
Meat: Is it your good friend, or old enemy? Tell us.Courtesy Another Pint Please...
Ok, Buzzketeers, buckle up for some meaty issues, juicy discussion, and humorless punnery. But first:

Do you eat meat?

Let me say off the bat that this isn’t a judgment thing. Yeah, I am judging you, but only on your grammar, clothing, height, gait, pets, personal odor, and birthday.

But not on your diet. So there will be no bloodthirsty carnivore or milquetoast vegetarian talk here. Y’all can have that out on your own time.

This is more of what I like to call an entirely unscientific poll about meat, the future, and your deepest secrets. (Depending on what you consider secret.)

When you get to the end, you can see what everyone else voted.

Tell us, do you eat meat? (click here for the poll)

Or jump right to the results.

Or go ahead and discuss this stuff.

Apr
16
2011

For some reason paleontology news this week seems to cover the whole sensory gamut. First off, there’s a new discovery in China of a Mesozoic mammal named Liaoconodon hui that adds more transitional evidence regarding the evolution of the reptilian lower jaw into the middle ear bones found in mammals. The research was done by paleontologists from the American Museum of Natural History and the Chinese Academy of Sciences.

The guys over at Witmer Lab write about being involved in a study of the evolution of olfaction from small theropod dinosaurs to modern birds. The olfactory bulb is the part of the brain that detects odor, and it seems some modern birds inherited a pretty good sense of smell from their dinosaurian ancestors. Here's some video about it from the Witmer Lab site.

In the seeing department Jennifer Viegas over at Discovery News has a slide show presentation (with text) about a new study appearing in Science that suggests some dinosaurs and other prehistoric reptiles were nocturnal. The study is based on the sceleral ring and larger eye sockets found in the fossil remains of some prehistoric animals. Larry Witmer also mentions the subject on his blog (it’s located below the olfaction post).

Touch and taste – the last two senses - are covered in a new study of lice evolution at the University of Illinois-Urbana, and with the discovery of a new, toothy dinosaur in New Mexico.

Kevin Johnson, an ornithologist at the UI-Urbana, proposes that since lice seem to specialize in the way they annoy their host animals, it’s likely that lice that cause today’s birds to nit-pick, scratch and preen, are descended from lice that pestered feathered dinosaurs. You can read about Johnson’s research here.

Ghost Ranch, New Mexico: The red beds here have produced fossils of a new early carnivorous dinosaur.
Ghost Ranch, New Mexico: The red beds here have produced fossils of a new early carnivorous dinosaur.Courtesy Mark Ryan
Lastly, Daemonosaurus chauliodus ("evil spirit reptile with outstanding teeth") is a new carnivorous dinosaur species found recently at Ghost Ranch in New Mexico. The buck-toothed theropod more-than-likely feasted on all the other creatures it shared its environment with 200 million years ago during the Triassic (yes, I know I’m probably stretching the taste sensory categorization here but I needed something). The discovery of Daemonosaurus in a block of Coelophysis remains is important because it alters scientific thought on the early history of carnivorous dinosaurs. The study was led by vertebrate paleontologist Hans-Dieter Sues of the Smithsonian and appears in the journal Proceedings of the Royal Society B. You can also read about it at Dinosaur Tracking.