Why does hair turn grey?

The color of hair - black, blonde, brown etc. - is determined by a pigment called as Melanin which is produced at the root of our hair follicles. Because of a variety of reasons the production of Melanin can stop. When this happens the hair loses its color and shows up as grey or white. One important and natural reason for hair to become grey is ‘age’.  As we grow old, the cells which produce melanin die. This unwanted milestone is achieved by different people at different time depending on genes, the legacy we carry from our parents. This is why some children develop grey hair at a very early age. 

Other than aging, the production of melanin can impede because of:  

• Lack of nutritious food, especially vitamin B. In some cases eating well balanced food also may not help as our body will not or have lesser ability to absorb few of the required vitamin.
• Ailments like thyroid, anemia, poor functioning of liver or kidney.
• Stress. Still a debated issue but few research reports indicate that stress can damage the cells which produce Melanin.   

The best and easiest way to avoid grey hair is to eat good well balanced food, abstaining from smoking, and eating tobacco, avoiding stressful thinking (easily said than done!). 

References: All above information is obtained from following sites: 

• http://www.zippy-health.com/grey-hair-notable-pointers-regarding-infant-greying 
• http://www.wisegeek.com/why-does-hair-turn-gray-as-we-age.htm    
• http://hubpages.com/hub/What-Causes-Hair-to-Turn-Grey-Vitamin-Remedies-for-Grey-Hair    
• http://www.dailymail.co.uk/health/article-1192561/Its-official-stress-really-does-make-hair-grey-protects-cancer.html#ixzz1Qgr9BLBq

How does an air-cooler work?

Think of the cool air you enjoy every time you sit beside a lake, beach etc. Air-cooler works on the same principle – Evaporative cooling.

Molecules on the surface of water are restless! Because of their acquaintance with surrounding air molecules they are relatively more energetic (molecular collisions). The moment they gain sufficient kinetic energy, they elope (overcome the shackles of intra-molecular forces). Result is moist air which is cooler. 

Let’s apply this concept on air-cooler.

The pump circulates water through the lateral pads (the dry grass thing). When the hot air in the room comes in contact with it, the surface water evaporates and cools the air. The rotating fan blows the cool air into the room. The amount of cooling depends on the humidity of the room. Lesser the humidity better it is - Less humidity means less water content in air, so it can suck in more.

My mum was complaining that all neighbors have fixed their coolers in windows. My dad never does that for her. While I was listening to her, it suddenly struck me why it’s done. Obvious again – Continuous supply of fresh dry air for cooling. This also means that unlike the common (?) belief we should not close all doors and windows. The moist air should keep moving out ensuring that humidity in the room is not high.

Thanks to this question, I revisited few fundamentals I learnt and forgot– Evaporation, humidity etc.

Why do we yawn?

Let’s start with fundamentals. Normally, when we breathe in, we inhale oxygen and our body uses it up. The body makes a waste product called as carbon dioxide that is exhaled from the lungs when we breathe out.

When we are sleepy, bored or tired, we breathe more slowly. So, our brain makes us take an extra breath, which is deep and long called a yawn, so that you can take in more of oxygen and give out carbon dioxide fully.

Yawning is an involuntary action that causes us to open our mouths wide and breathe in deeply. We know it's involuntary because we do it even before we are born. Research shows that 11-week-old fetuses yawn.

One question which I am still pursuing (googling is more appropriate word!) - What's behind this mysterious chain reaction of yawning?

References:

http://www.pediatriconcall.com/kidscorner
http://www.howstuffworks.com
http://www.coolquiz.com

What is JET LAG?

On my current trip to USA, I have been experiencing two things like never before - some strange discomfort and often encountering the phrase JET LAG. The rest of the story is based on my (res)earch to know how these two things are connected.

Jet lag also known as time zone change syndrome or desynchronosis is considered a sleep disorder that can affect everybody who travels across multiple time zones in airplanes. It happens due to de-synchronization between the body's internal time clock and local environmental cues. Our internal clock - also called circadian rhythm - which tells our body when it's time to be awake and when it's time to be asleep, is disrupted by jet lag. The more time zones crossed, the more likely we are to experience jet lag.Oxygen levels in an airplane cabin could also play a role in jet lag. As air pressure is relatively low in the airplane cabin, the amount of oxygen in the blood is reduced. A decrease in the quantity of oxygen can have an effect on physical and mental abilities, making us more sluggish, exhausted, and lacking in energy.


The symptoms of jet lag can be quite varied, depending on the amount of time zone alteration. It could be - headaches, fatigue, irregular sleep patterns, insomnia, grogginess, irritability, mild depression, constipation, diarrhea, nausea, ear aches and swollen feet.

Few simple yet interesting learning’s for me are:

 - The symptoms of jet lag are usually more obvious when someone travels east, rather than west. This is because the body finds it easier to adapt to a somewhat longer day (in the west) than a slightly shorter one (in the east).  Hence the condition is NOT associated to the distance of the flight, but to the trans-meridian (East-West) distance travelled. For example, a 10 hour flight from Europe to southern Africa does not cause jet lag, as travel is primarily north-south. A 5 hour flight from west to eastern coast of the United States may well result in jet lag.


- Sunlight is a key factor on the internal clock. This is because the pineal gland, a part of the brain that influences circadian rhythms, reacts to varying levels of environmental light. Retina of the eye transmits the light-levels to brain which is then sent to pineal gland. At night, the pineal gland releases the sleep-promoting hormone melatonin which stops during the day. This means, one way to adjust to new time zone is by exposing oneself to daylight.


Now who can get Jet-lagged? Anybody, regardless of frequency of travel and any age can build up this condition. However, it is more common in individuals over 50 years and is relatively rare in children.

Any way we can prevent this annoying lag? Yes we can to some extent, through few precautions.

1) General belief is that a drink will relax and make trip easy. Unfortunately, alcohol and jet lag do not mix.

2) Drink plenty of fluids, try staying hydrated before and after your flight. And yes, the best fluid is water.

3) Get some sleep. If it is night time at your destination while you are on your flight, try and get some sleep.

4) Keep active. Walk around the cabin occasionally, and regularly stretch your arms and legs when you sit.

Another easy way is to adjust your watch so that it matches the time of your destination. This will help adjust more quickly to your new time zone.