Why Do Bees Build Hexagonal Cells?

Have you ever wondered why bees build hexagon-shaped cells?

I have some odd things that keep me up late at night.  This is one of them.  In researching bee-keeping (an item on my bucket list) I keep going back to one simple question. Why do bees make hexagonal shaped cells? Isn't it fascinating? Why hexagon? Why not other shapes? Why not triangles or octagons? And these apparently simple, instinct-driven creatures could build the perfect-six-sided-hexagon which, when you stack them up together, form a perfect array of honeycomb.

Image: www.bee-hexagon.net

More than 2000 years ago, Marcus Terentius Varro proposed an answer to this question. He thought maybe honeycomb built of hexagons can hold more honey and require less building wax, and this answer has since been called "The Honeybee Conjecture".

Supporting this hypothesis is that first up, we all know that honeycombs store honey. Honey is what sustains the entire colony, so obviously it's very precious. A typical colony consists of 100,000 individuals, so you need a lot of honey to keep them alive. To store that much honey, you'll need a warehouse big enough to store them, but small enough to prevent thieves like the Japanese Giant Hornets (as long as your thumb), bears and other creatures from breaking in. In fact a single cell is just big enough to let a single worker pass through.

The Japanese Giant Hornet is at least five times larger than the honey bee. Image: waynesword.palomar.edu

So you need to start with a shape. Shapes like circle, pentagon, heptagon and octagon are bad shapes because you can't stack them up together without leaving gaps. And when you're talking about building a place to store as much honey as possible, every gap is considered a waste of space.

So that leaves us with triangle, square and hexagon. Out of these three, why hexagon?
It turns out that hexagon uses the least wax to produce compared to triangle and square of the same cross-sectional area.

To produce a square with area, A=100cm2, the circumference is 40.0 cm.

To produce a triangle with area, A=100cm2, the circumference is 45.588 cm.

To produce a hexagon with area, A=100cm2, the circumference is only 37.224 cm.

Ironically, the one with the least number of sides (triangle) is the one that requires the most wax to build.

This means that by building hexagon-shaped cells, the bees can reduce the usage of wax, which is also made from honey (now that makes sense).

Now one could think there are a lot of calculus loving bees out there engineering perfect hives.  But if we revisit our friend Darwin, we can easily see how less effort, plus more energy equaled a more successful hive and thus the genes for geometry learned bees get passed along.

Now that i've got the hexagonal hive business all sorted out, I need another problem to ponder late at night.

Not quite a Man O'War

Image via Wikimedia

Velella is the scientific genus of this amazing colonial animal. Firstly; By-the-wind Sailor, what a wonderfully romantic name!  They get it from their lifestyle which is similar to our very own Portuguese Man o’ War, although they are much smaller and clearly a lot less famous. Sailors reach about 7 centimetres across and have quite a tough, rigid sail to harness the wind. It’s actually made of chitin, like insect exoskeletons. The sail I mean, not the wind. Like the Man o’ War, individuals have sails that bear either left or right into the wind so that when thousands are washed up on a beach, another few thousand have been sent in the opposite direction. When you have one sail and no oars or boat propeller I suppose something like that is necessary. A 50-50 chance is better than none at all! Surrounding the sail are rings of air filled tubes to provide buoyancy.

Image via Wikipedia

Despite the lovely name and care-free (until you hit the rocks) life style, By-the-wind Sailors are Cnidarians, which means they are meat eating, stinging creatures. In this case the tentacles are short, only about 1 cm long, and hang down below the edge of the disc and into the sea. They feed on tiny plankton of various kinds and seem to be completely harmless to humans, clearly a terrible disaster for their chances of fame. Why are they harmless? Likely because their stinging cells are too short to penetrate our protective skin.

It looks like most people consider By-the-wind Sailors to be made up of hydroid colonies, again, much like the Portuguese Man o’ War. Instead of one, big animal, it’s actually made up of lots of little ones that work together. It looks like others disagree and prefer to see it as something more like a floating, upside down Sea anemone with a sail on its foot. The entire concept of a colony of animals living as one is amazing and a modality us humans should learn from.

Image Wikipedia

Either way, By-the-wind Sailors are all either male or female. When they mate, they first produce thousands of tiny larvae that are free flowing plankton. These are about 3 mm across and are slightly brown because of their friends; inside their bodies are tiny microalgae that can gain energy from the Sun and provide some to their host. They are effectively paying for bed and board, which is nice of them. Eventually, the jellyfish will release sperm or eggs into the water to create new By-the-wind Sailors. It is a pretty odd life cycle, but then Cnidarians are utterly immersed in oddity so we’ll just have to get used to it.

These are rather common finds along the beaches in the late summer and fall. Loads of them get washed up all along the West coast of the US every year and they’ve even done the same in good ol’ Blighty. They look lovely with their rich, blue colours and concentric circles, yet there doesn’t seem to be great deal written about them. Shame. Looks like the Portuguese Man o’ War has stolen all the limelight!

How Do Tornadoes Form?

via Scientific American:

Yesterday the middle of American was hit hard by tornados. Illinois and surrounding states suffered devastating losses. and damage. Tornadoes occur on every continent except Antarctica, but more form over the central US than anywhere else in a zone called Tornado Alley. That's because conditions in the alley are ideal for creating tornadoes.

Warm humid air low on the ground moves north from the Gulf of Mexico and collides with cool dry air high above the ground  rolling in from the Rocky mountains. The collision of air masses creates a supercell, a massive thunderstorm that has a strong rotating updrafted air.

The difference in speed between the faster high winds and the slower low winds causes the air in between to rotate around the horizontal axis. If one end of the rolling air gets caught in the updraft, it's being upwarded into the funnel cloud. Its spin gets tighter and faster and the cloud becomes longer. Rain or hail from the thunderstorm can then push down on the tail of the funnel cloud until it reaches the ground, forming a tornado.

The top wind speed of most tornadoes is usually under 110 miles an hour and most are on the ground for less than 10 minutes. However, extreme tornadoes are truly extreme. The longest tornado path was cut by the tri-state tornado on March 18th 1925. It tore up property for 219 miles and was on the ground for well over 3 hours and killed 747 people. Always respect Mother Nature and the weather, and pay attention to those weather alerts.

It has been a while....

Yes folks, it had been a while.

First a few thing.

1. The blog is officially just over a year old. 

2. Due to circumstances I should have more time to write and focus on it for the short term.

So I do apologize for allowing things to slide for a bit.

Jonathan

How Does Snake Venom (Hemotoxin) Affect You?

WARNING - Not for the faint of heart.

Snake venom is one of the most sophisticated bio-weapon in the natural world. A single drop of cobra venom is enough to kill several men in a few hours. 

There are three different types of snake venom: hemotoxin which affects blood, neurotoxin which affects your nervous system, and cytotoxin which affects your muscles.
To develop antivenom, we need to first understand how venom works.

I recently watched a video that features a Russell's viper, one of the most feared snakes in the world. Its venom is hemotoxic, and the video shows how it affects human blood.

The video shows a wrangler milks the venom, which is then mixed with a glass of blood.

Look at the fangs!

 Within seconds, the blood clots into some form of jelly-ish solid matter.

According to wikipedia,

The coagulant in the venom directly activates factor X, which turns prothrombin intothrombin (that causes coagulation) in the presence of factor V and phospholipid. 

In the dRVVT (dilute Russell's viper venom time) assay, low, rate-limiting concentrations of both Russell's viper venom and phospholipid are used to give a standard clotting time of 23 to 27 seconds.

If diluted Russell's viper venom could induce blood coagulation in 23 seconds, imagine the time needed to clot your blood if you're injected with pure viper venom. 5~6 seconds?

Of course, blood clotting is just one of the many symptoms of viper bite. You would get necrosis (death of cells) near the bite, low blood pressure, vomiting, facial swelling, and kidney failure. Death would soon follow if untreated.

Necrosis from a Rattle Snake bite. Image: rattlesnakebite.org

Even if you do survive the bite, chances are that you would suffer damage to your pituitarygland, a  hormone-secreting gland situated at the base of the brain, causing it to stop secreting the vital homeostasis-regulating hormones, a condition called hypopituitarism.

I now have a new found respect for vipers.



video link:
http://www.youtube.com/watch?v=4WvnjCkLbvY 

info: 
http://en.wikipedia.org/wiki/Daboia#Venom 
http://www.wisegeek.com/how-does-snake-venom-affect-the-human-body.htm 
http://en.wikipedia.org/wiki/Hemotoxin

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.