Research Is A Dangerous Business for Some

When people talk about risk at work, they normally mean the risk of getting fired, getting hit by a bus, and probably encountering some minor accidents like electrocution while charging their electronics. 

Unlike these risks, the risks you encounter during research are far more unpredictable because you work with unpredictable subjects; the weather (climate scientists), wild animals (zoologists), chemicals (chemists), and sometimes, the product of your own research (physicists). Even in social sciences, the research is often far more dangerous than your average nine-to-five job.

One particular technique in behavioral psychology, called participant observation, involves taking part in the activities of those you want to study. For example, if you wish to study the drug cartel, you would need to actually get your hands dirty. Sociologist Mick Bloor, a professor at the Cardiff School of Social Sciences once ended up in a bar fight while studying male prostitution in Glasgow. Lorraine Dowler from the Pennsylvania State University was forced to flee when her interviewee became the target of a street-level assassination attempt. Social scientist Frank Burton woke up one morning to find a submachine gun pointed at him. The body of Ken Pryce was found washed up on a Caribbean beach after investigating criminology in Jamaica.

These are just of the few workplace hazards that face researchers at work. We have yet to include stories of marine biologists who have face sharks and other dangerous marine predators, zoologists battling malaria, herpetologists getting bitten by snakes, and conservationists and medical scientists battling fanatic animal-rights activists.

Image: www.the-scientist.com

In April 2013, an animal-rights group that calls itself Fermare Green Hill (or Stop Green Hill) occupied an animal facility at the University of Milan, Italy, at the weekend, releasing mice and rabbits and mixing up cage labels to confuse experimental protocols. Researchers at the university said that it will take years to recover their work. Michela Matteoli, a neurobiologist who works on autism and other disorders and lost most of her own research in the attack, says that she found some research students crying in the disrupted facility on Monday morning. Many of the animals at the facility were genetic models for psychiatric disorders such as autism and schizophrenia.

A study conducted in 1994 by Brian D Crandall and Peter W Stahl intended to investigate whether humans could digest bones. They trapped some shrews and after skinning and brief evisceration, they boiled one of the carcasses for approximately 2 minutes before swallowing it whole; head, limbs, body and tail. Without chewing.

So it's very disrespectful for anyone to brush aside any researcher's project and label them as useless.

Research is not just for geeks. It's also for James Bond. 

Toxic Birds Make For Sad Lice

Toxic Birds Make for Sad Lice.

Photo by John Dumbacher from
the California Academy of Sciences

SEM photograph from phthiraptera.info

Today's entry is a bit divergent from the norm.  I saw a giant biting fly nipping at one of my dogs this morning.  Besides pharmaceuticals, I wanted to know what natural defenses against insects were out there.  Alas, no toxic dog fur existed in my brief literature search, but I did come across toxic bird feathers that combat lice.

So without further delay, I present the birds with toxic (to insects) feathers.

Birds are host to an impressive diversity of external parasites, from insects (including lice, fleas, bugs and flies) to mites, ticks and even fungi and bacteria. These parasitic organisms can have severe negative effects on host fitness. Therefore, it is not surprising that birds invest a lot of time engaged in behaviors such as grooming, preening, dusting and sunning in attempts to rid themselves of their ectoparasites. A handful of unique birds from the genus Pitohui have an interesting physiological adaptation that may assist in the fight against parasite infestation: feather toxins.

Yes, toxic birds. The six species of Pitohui, which are endemic to New Guinea have been found to carry in their skin and plumage. These are the same potent toxins as those found in the skin of poison dart frogs (Phyllobates spp.) and are some of the most toxic natural substances known. The toxin present in the Pitohui is known as homobatrachotoxin and like all batrachotoxins is a neurotoxic steroidal alkaloid capable of de-polarising nerve and muscle cell membranes. The level of toxins present in Pitohui tissue varies between species and geographic location. The most toxic species is the hooded pitohui (Pitohui dichrous), from which merely handling an individual can cause numbness, sneezing, and irritation of the eyes and sensitive mucous membranes. It has been hypothesised that the high proportions of toxin present in the Pitohui skin and feathers could provide the bird with a barrier from ectoparasites that live and feed on skin, feathers and subdermal blood supplies.

batrachotoxins.

A curator and department chair of Ornithology and Mammology at the California Academy of Sciences was the first to test if the presence of toxins in Pitohui feathers and skin would deter or kill chewing lice (order Phthiraptera). In order to investigate this he conducted a series of choice and lifespan experiments. Dumbacher found that when individual lice in the laboratory were given a choice of two feathers (one toxic Pitohui feather and one non-toxic non-Pitohui feather) there was a statistically significant preference against feeding or resting on the toxic feathers. Lice exposed to the highly toxic feathers of P. dichrous rarely showed signs of eating, with many becoming immobile and inactive. In some cases the louse would simply drop off the toxic feather. In a natural setting, immobility and lower feeding rates reduces the damaging effect of the lice and may even allow the birds to more easily remove or dislodge the parasites mechanically by preening or flying. Since this part of the study showed that the lice exhibited an active choice against the naturally toxic Pitohui feathers we can conclude that homobatrachotoxin has the potential to act as a repellent against these parasites.

The Curator also determined that the natural levels of homobatrachotoxin in Pitohui feathers greatly increased louse mortality. The results of the lifespan experiments showed that the mean lifespan of lice exposed to feathers of either high or low level toxicity was half that of those on nontoxic feathers. Interestingly, the mean lifespan of the lice on the toxic feathers was similar even though the toxin levels in P. ferrugineus are ten times lower than P. dichrous. Therefore, Pitohui feathers with lower toxin levels may not have been potent enough to repel lice during the choice experiments but were as effective in increasing louse mortality as the highly toxic feathers. Increased mortality in lice could have many benefits for the host. Less time spent on the host will reduce the negative effect of each individual louse.

One observation from the study was that non-toxic feathers showed obvious damage from lice feeding. This may be due to the extended life span offering additional feeding time, or the lice simply find nontoxic feathers more palatable. Further investigations may provide insight into additional  benefits, for example whether or not the potent toxin is able to reduce louse fecundity. If mating in lice is decreased then subsequent generations of lice are also reduced. Smaller populations would cause less irritation to the host and also be less visible to potential mates. Additionally, less ectoparasites would reduce time spent mechanically removing them and more time to invest in other activities. The results of Dumbacher's study suggest that the naturally occurring homobatrachotoxin found in the skin and feathers of the Pitohui repels and kills lice. The presence of a powerful toxin in skin and feathers has the potential to create a formidable barrier and protect the bird against infestation from ectoparasites.

Reference:

Dumbacher, J. P. (1999). Evolution of toxicity in Pitohuis: I. effects of homobatrachotoxin on chewing lice (order: Phthiraptera). The Auk, 116: 957-963.

How much water is there on Planet Earth?

How much water is there on Earth?

We often hear people say 70% of the Earth's surface is covered by water. Oceans and seas constitute the largest amount of water, roughly 96.5%. The rest exists in lakes, rivers, underground water sources, in our body, and in your pets.

That does sound a lot isn't it? In reality, it's really not that much.

The blue spheres in the picture above show the relative amount of Earth's water in comparison to the size of the Earth. Surprisingly small isn't it? But we have to remember that water spreads evenly over the entire planet forming a thin layer of liquid, and that's how the little blobs colour our Earth blue.

Let's start with the smallest blob, the one hanging above the state of Georgia. It represents the surface-fresh water sources in all the lakes and rivers on the planet, i.e. the water that we use everyday. The diameter of this sphere is about 56.2km, and the volume of this sphere is about 93,113 km3.

The intermediate sphere, above Kentucky, shows the Earth's liquid fresh water in groundwater, swamp water, rivers, and lakes. We get our fresh water from rivers and lakes, but underground water sources are most of the time unavailable. This sphere has a 272.8 km diameter, and a volume of 10,633,450 km3.

The largest blue sphere represents all the water on Earth-seas, oceans, lakes, rivers, underground water. That sphere has a radius of 1385 km, and the volume would be 1.386 billion km3.

So when you compare the amount of water that can be used to the amount of water that cannot be used, the percentage is pathetically meagre-only 0.0067% of the water on Earth is reachable and usable by humans and land animals. What's worst, a large amount of that water is heavily polluted especially those in congested cities in India and China, rendering them essentially unusable.

Image: healthfactshealthtips.com

Unfortunately there are still intellectually-retarded rich capitalistic buffoons somewhere who love to stand (or sit?) for hours on end in their showers and waste clean water needlessly while they imbibe in their sordid fantasy.

But to think on the positive side, it's amazing so many water-carrying asteroids actually hit the Earth during its infancy to result in that much water on Earth today.

So the factoid that the Earth is COVERED by water on about 75% of its surface is in fact still valid, but this does put that precious resource into perspective.


info: http://webcache.googleusercontent.com/search?q=cache:http://blogs.discovermagazine.com/80beats/2012/05/14/this-tiny-sphere-is-all-the-worlds-water/

8 Glasses of Water A Day--How Did It Come About?

I have always heard you need 8 glasses of water a day.  I nag my own children to come close to this level of H2O consumption. 

I prefer to get my liquids via Diet Peps but most if not all the medical advisers I've met thus far have said that drinking 8 glasses of plain water a day is a must, in addition to other liquid like coffee and soup. That sums up to like... 10 glasses of liquid a day?

Image: www.just-eat.co.uk

Do we really need that much water in our system everyday? Who proposed that ludicrous idea anyway?

It turns out that there is no scientific proof to back the "8 glasses of water a day" rule. It was first written by Dr. Frederick J. Stare, one of the top nutritionists in the U.S in a book co-authored with Dr. Margaret McWilliams in 1974.

Dr. Stare wrote that:

“How much water each day? This is usually well regulated by various physiological mechanisms, but for the average adult, somewhere around 6 to 8 glasses per 24 hours and this can be in the form of coffee, tea, milk, soft drinks, beer, etc. Fruits and vegetables are also good sources of water.“

So what he meant was actually:
You are recommended to gulp down 6 to 8 glasses of liquid per 24 hours and this can be in the form of flavored drinks, plain water, soup, or even fruits and vegetables.

But how did that become "8 glasses of water a day"?
Another nutritionist, Dr. Irwin Stillman, who created the populat "Stillman Diet" in 1967 was the one who actually propagated the idea of drinking 8 glasses of water a day.

 “[Dr. Stillman] insisted on a minimum eight 10-ounce glasses of water daily… The reason for the eight glasses of water is to provide sufficient water for the kidneys to use in washing away the fatty acids resulting from the breakdown of fat, says Dr. Stillman. A bit later, however, he writes, “The ‘why’ of this functioning is not fully understood.”“

So how much exactly the liquid do we need each day?
Well that depends on a plethora of factors: your activity level,  job, your routine, your health, the weather, etc. Athletes and  people who work out a lot obviously need more water. People who live in warmer regions obviously need more water. But for the average person, the amount of water needed is proportional to the amount of liquid excreted via urine, sweat, and evaporation, which is about 3 liters for men and 2.2 liters for women per day. That translates into roughly 9.23 glasses (325ml) and 6.77 glasses of liquid for men and women respectively. So the numbers stated by Dr. Stare are still valid.

But remember, 9.23 glasses of either tea, coffee, soup, or plain water.



info: http://www.mindthesciencegap.org/2012/10/22/you-need-to-drink-8-glasses-of-water-a-day-a-history-lesson/ 

Leeches

I used to take care of a colony of leeches for an exhibit.  Recently the topic resurfaced and I decided to wax poetic about these nifty creatures.

Alright this is going to be a really disgusting post for some people, so reader discretion is advised.

There are freshwater, terrestrial, and marine leeches, meaning, we cannot escape from this vampire. Like earthworms, leeches are hermaphrodites (an animal or plant that has reproductive organs normally associated with both male and female sexes). Some, but not all, leeches are hematophagous, meaning having a strong taste for blood.

Humans have coexisted with this parasite for ages. Now that we have moved away from the jungle, they followed us to dwell in our drainage system, man-made lakes and artificial forest. It's a common sight to see a leech slowly making its way in the drain sometimes, feeding on unwary dogs and cats that pass by. This creature even found its way into the hospital now, where doctors utilize its blooding sucking ability to withdraw clotted or contaminated blood from patients. Leech produces a special enzyme when it bites, which prevents blood from clotting, and thus it can suck on continuously until it is full. A string-thin leech would feed furiously until becoming as thick as our thumb.

Once latched onto its victim, a leech will not release its bite easily. One recommended method of removal is using a fingernail to break the seal of the oral sucker at the anterior end of the leech, repeating with the posterior end, then flicking the leech away. As the fingernail is pushed along the person's skin against the leech, the suction of sucker's seal is broken, at which point the leech should detach its jaws.

A common but medically inadvisable technique to remove a leech is to apply a flame, a lit cigarette, salt, soap, or a caustic chemical such as alcohol, vinegar, lemon juice, insect repellent, heat rub, or certain carbonated drinks. These cause the leech to regurgitate its stomach contents into the wound and quickly detach. However, the vomit may carry disease, and thus increase the risk of infection.

Simply pulling a leech off by grasping it can also cause regurgitation, and adds risks of further tearing the wound, and leaving parts of the leech's jaw in the wound, which can also increase the risk of infection.

An externally attached leech will detach and fall off on its own when it is satiated on blood, usually in about 20 minutes (but will stay there for as long as it can).Internal attachments, such as nasal passage or vaginal attachments, are more likely to require medical intervention.

There are several cases of internal attachment happening in remote areas of the world. Three years ago, a nine-year-old girl was admitted to La Merced hospital in Peru with a headache that had lasted for two weeks and a strange “sliding sensation” in her nose. Her parents quickly discovered the source of the problem – a sizeable black worm lodged up her right nostril. They quickly sought medical help and it came in the form of Dr Renzo Arauco-Brown, who removed a seven-centimetre leech from the girl’s nose. Two more cases were found in 1997.  Both had been removed from the nostrils of young boys in 1997. Like the most recent case, these children had also been bathing in local lakes and streams, which is almost certainly how they picked up their vampire.

While most leeches are found on the skin, some also specializes in feeding on mucous membranes, such as those found in the nose, eye, vagina, anus and urethra.

As you can see, this animal will try anything in order to feed on our blood. And so, medical practitioners have come up with a way to satisfy the leeches' need, while clearing ailment off the patients. The use of leeches in medicine dates as far back as 2,500 years ago when they were used for bloodletting in ancient Egypt. All ancient civilizations practiced bloodletting including Indian and Greek civilizations. Hence, medical practitioners today have a strong reason to use this ancient method to cure sicknesses, but not for me please~ I still prefer the conventional injection-medicine method.

Isopods found in the most unusual places.

Yes you read that right.

Isopods are small marine crustaceans and not commonly a topic of blogs or household conversation.

Recently there has been a meme around the internet of an isopod on a fishes mouth. In fact, it was often presented as a guessing game and all sorts of guesses were baby fish, cleaner shrimp and all rather benevolent causes.

I knew this was not a baby fish. I didn't recognized the species initially, and the first thought that came to me was that those two were the undigested prey of the fish. But the marine biologist in me wasn't happy with the answer. Were they really the undigested prey of the fish? They looked nasty, with segmented body and evil little eyes. They have seven pairs of claws underneath their belly. SEVEN! What kind of animal that needs fourteen limbs?

So I dragged out the old Invertebrate Zoology text book for information for these animals, and ta-da! They were actually the parasitic crustacean called tongue-eating louse, Cymothoa exigua.

This animal enters fish through the gills, and attaches itself to the base of the fish's tongue. It suck the blood from the tongue, causing the tongue to slowly waste away-a condition called antropy. So it's basically eating away the fish's tongue. The louse will then attach itself to the muscle of the tongue, and the fish can use the parasite just like a normal tongue.

Image: threadless.com

The female is typically larger, and attaches itself on the tongue, while the smaller male usually attaches itself behind the female. The two creatures I found inside the fish, one of them was male and the other female.

Image: themanyfacesofspaces.com

Wikipedia says that the parasite is found mostly in the North and South American seas, until one was found in the United Kingdom in 2005, which means there are these parasites in the Atlantic as well.

Which brings me to another topic, ticks.  I hate them. Disgusting little creatures and they will be the subject of another blog entry. But these isopods remind me of tick on fish.  yeck.



info: http://www.dnr.sc.gov/marine/sertc/Isopod%20Crustaceans.pdf

The Curious Case of Mosquitoes

Life really sucks if you're a mosquito. Apart from the ability to master flight, there's no good in being a parasite--your dinner can turn around and smack you dead if you're not fast enough, and your food can cause your little body to overheat. 

Oh yeah, and some neighbors will hunt you down and suck the blood right out from your belly.

According to a study in the journal Current Biology, Chloé Lahondère and Claudio R. Lazzari found out that these little vampires excrete and hang on to a single bead of blood to reduce the heating effect via evaporation.

High temperatures can have deleterious effects on insects' physiology. But some insects are dependent on warm-blooded host. And since they do not sweat like us, there must be some kind of cooling strategy to keep them from dying.

The scientists conducted a real-time infrared thermographic analysis of mosquitoes' body temperature during feeding on both warm blood and sugar solution. They found that anopheline mosquitoes can decrease their body temperature during blood feeding thanks to evaporative cooling of fluid droplets, which are excreted and maintained at the end of the abdomen. The mosquitoes that excrete a drop of blood have lower body temperatures than those that don't.

Image: cosmosmagazine.com

But life isn't just about keeping cool at the dining table. Engorged mosquitoes have to be wary of their hungry neighbors too, because they will attempt to steal your food, right out from your belly.

A technician from the Department of Entomology, University of Georgia reported that she saw a mosquito taking blood from another engorged one.

So the scientists prepared two groups of Aedes mosquitoes; one group allowed to dine on a chicken, while another starved. Right after the feeding, the starved ones were put together with the engorged mosquitoes, which remained motionless. The scientists reported that the starved individuals were attracted to the engorged mosquitoes and attempted to feed. Some eventually succeeded in taking blood from their burdened neighbors.

Aedes aegypti feeding on an engorged Aedes aegypti. Image: "Mosquitoes Feeding On Engorged Moquitoes", A. Burns Weathersby, Hyong-Sun Ah, John W. McCall.

I ain't sure about you, but I prefer to stay human.

So as we head into summer BBQ season remember your flying friends and all the trouble they go through for a quick meal. Then smack them down.

info:

http://www.scientificamerican.com/podcast/episode.cfm?id=mosquitos-use-drop-of-blood-to-keep-11-12-15

http://citebank.org/sites/default/files/MN_V31_N1_P110-111.pdf

How The Zebra Got Its Stripes?

So the other day I was driving my kids around and they asked how did the zebra gets its stripes.

The explanation I saw from documentaries stated that zebra evolved its stripes to confuse the lion.

Lions are color blind,as are many cats,  so a group of rampaging zebras can be extremely confusing and headache-inducing. With the tall African savannah grasses, one can easily see that the stripes, combined with the tall grasses could easily break up the lines of a zebra and be confusing to predators.  Sounds right, so I figured that wrapped up that little science lesson.  But I got home and did some research on the subject.

I found an entirely plausible other reason for the strips. Gabor Horvath and colleagues from Hungary and Sweden have come up with another explanation: zebra's stripes ward off blood-sucking parasites.

Image: animals.howstuffworks.com

Like us, animals hate parasites too, and one parasite, the female horseflies (tanabids) can deliver one hell of a bite. Like female mosquitoes, they feed on mammal blood for reproduction, and they carry diseases too.Locally mosquitos transmit the dinofilaria (Heartworm) parasite to dogs and cats, so it makes sense from an evolutionary viewpoint to develop a natural "Frontline" so to speak.

Image: en.wikipedia.org

They lay their eggs on stones or vegetation close to water, guided by the horizontally polarized light reflected from the water surface. And these evil vampires are also guided to their meals via horizontally polarized light reflected from animal skin.

Image: whatis.techtarget.com

To test this, the team traveled to a horsefly-infested farm in Budapest and set up three horse model; a white, a dark, and a striped model. Interestingly, the striped model was the least attractive to horseflies. The team also varied the width, density, and angle of the stripes, and found out that narrower stripes attracted fewer tanabids.

The team pointed out that developing zebra embryos start out with a dark skin, only to develop white stripes afterwards. It's possible that evolution has favored the development of zebra stripes to confuse color-blind predators, as well as ward off blood-thirsty vampires.

Should we do the same to ward off mosquitoes? Who knows, perhaps I will develop a line of striped clothing for hikers and make a fortune warding off blood sucking insects. At the very least it may save you from a Lion attack.


info: 
Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes, Ádám Egri et. al, J Exp Biol 215,  March 1, 2012  736-745. 

Evolution of the Whale

Evolution of the Whale

The Blue Whale is the largest living creature on the planet.  It is hard to believe it evolved from  a land mammal roughly the size of a dog. While this is accepted as science fact, I have had many a discussion with those unwilling to believe this. But who cares~ no one believed in Max Planck in the first place, not even himself, and everyone was laughing at Charles Darwin when he suggested that we are closely related to macaques.

The cetaceans (whales, dolphins and porpoises) are marine mammal descendants of land mammals. Their terrestrial origins are indicated by:

• Their need to breathe air from the surface;
• The bones of their fins, which resemble the limbs of land mammals
• The vertical movement of their spines, characteristic more of a running mammal than of the horizontal movement of fish.

The question of how a group of land mammals became adapted to aquatic life was a mystery until discoveries starting in the late 1970s in Pakistan revealed several stages in the transition of cetaceans from land to sea.

This animal existed 50 million years ago by the rivers of southern Asia, walking on slender legs tipped with hooves, and takes to the water whenever it senses danger

It is called Indohyus (meaning India's pig)

and it is the earliest known relatives of today's whales and dolphins.

According to molecular evidence, the closest living relatives of whales are, quite surprisingly, the artiodactyls, a group of hoofed mammals that includes deer, cows, sheep, pigs, giraffes, camels and hippos, yet not a single one of them bears even a passing resemblance to whales and dolphins. Among the group, the hippos are evolutionarily closest and while they are at least at home in water, their family originated some 35 million years after the first whales and dolphins did.

Even though Indohyus had the elegant legs of a small deer and walked around on hooves, it also had features found only in modern and fossil whales.

It's jaws and teeth were similar to those of early whales, but the best evidence was the presence of a thickened knob of bone in its middle ear (involucrum). This structure helps modern whales to hear underwater, it’s only found in whales and their ancestors, and acts as a diagnostic feature for the group.

We should, however note that this animal IS NOT the direct ancestor of whales, it is only a sister group to the ancestors of whales. Got it?

So why did they go aquatic? Scientists speculate that whales developed from an Indohyus-like ancestor that fed on plants and possibly small invertebrates on land, but fled to water to escape predators. Over time, they slowly turned into meat-eaters and evolved to swim after nimble aquatic prey.

For a much more in-depth comparison see http://en.wikipedia.org/wiki/Evolution_of_cetaceans

Info gleaned from http://blogs.discovermagazine.com/notrocketscience

How Does Fire Behave in Zero Gravity?

Most of us don't know how fire behaves in zero gravity. 
Well... the movies were wrong.

Let's look at this picture.

Image: ynput.com

Trying to come up with a plausible explanation?
Allow me to enlighten you instead.

Fire needs oxygen, and that's readily available in Earth's atmosphere. Out there in space we have meager(practically none) supply of oxygen, and so astronaut cannot start a fire in outer space. If there's an explosion out there in space, the fire would quickly die away rather than burning the whole thing into ashes.

Image: cinem7.com

In the spacecraft, on the other hand, is a totally different story. We have ample supply of oxygen in a spacecraft, but no gravity, which is why we often see videos of astronauts floating about in spacecraft. Here, fire can start but it doesn't behave the way it does on Earth.

Image: futurecamping.com

On Earth, gravity pulls the air onto the ground, and so we have plenty of air around us. When fire burns, it heats up the air around it, causing circulation of air--hot air rises whilst cool air gets pulled downward. The section of air close to the fire rises and pulls the fire with it. This circulation of air is the reason behind the characteristic shape of fire we see here on Earth.

But in a spacecraft hanging above us in the orbit, there is no gravity. So there is nothing to pull the air downwards--meaning there is no air circulation. It still burns the oxygen around it but there is no gravity to pull cool air downwards to enable any air circulation. The fire starts but it just stay there. It doesn't flicker as it does on Earth and if there is nothing to propel fresh air(in this case, oxygen) towards it, the fire would slowly die away.

Savvy?