Friday, August 16, 2019

HADOOP

 Hadoop
Hadoop - Data Science Tutorial - Edureka
Hadoop is a framework which helps us to store and process large datasets in parallel and in a distribution fashion.
Let’s focus on the store and process part of Hadoop.
Store
The storage part in Hadoop is handled by HDFS i.e Hadoop Distributed File System. It provides high availability across a distributed ecosystem. The way it function is like this, it breaks the incoming information into chunks, and distributes them to different nodes in a cluster, allowing distributed storage.
Process
MapReduce is the heart of Hadoop processing. The algorithms do two important tasks, map and reduce. The mappers break the task into smaller tasks which are processed parallely. Once, all the mappers do their share of work, they aggregate their results, and then these results are reduced to a simpler value by the Reduce process. To learn more on Hadoop you can go through our Hadoop Tutorial blog series.
If we use Hadoop as our storage in Data Science it becomes difficult to process the input with R Studio, due to its inability to perform well in distributed environment, hence we have Spark R.

Monday, September 3, 2018

Why do people sneeze?

Why do people sneeze?

When you sneeze, you are likely to hear one of these responses, ranging in inspiration from the medieval to the hygienic. Different cultures throughout history have interpreted a sneeze as either an auspicious sign or a bad omen, but it may be said that both are right: Sneezing is the good that gets the ill out.
“Sneezing is basically ‘nature’s broom,’” says Dr. James Banks, an allergist and immunologist in private practice in Arnold, Md. “It is a way our bodies purge foreign matter that has invaded our noses.”
Particulates are the usual suspects, including dust and common allergens like pollen or animal dander. Sneezing also expels unwelcome germs when we are sick, which has given rise to the sanitary concerns about honking away in public places. And for good reason: a single sneeze can produce some 40,000 aerosolized droplets containing a hefty amount of infectious organisms, according to a 1998 article in the American Journal of Infection Control.
It’s not just allergies and illnesses that can produce that familiar tickling in the nose. Banks explains: “People sneeze for a lot of reasons other than just getting something up their noses. Clinically speaking, we consider sneezing a non-specific reaction, because there are a lot of sources that irritate.”
For example, some people experience a round of sneezing after a large meal, which has led to the coining of the term snatiation, a combination of sneeze and satiation. There is also a phenomenon with a known genetic basis called the photic sneeze reflex, which causes about one-third of people to sneeze from looking at a bright light source, such as the sun. Sigmund Freud has even speculated on the kinky psychological origins of an otherwise innocuous sneeze.
“Overall, it is not a clear-cut reflex,” says Dr. David Kaufman, an associate professor in the department of otolaryngology at New York University Medical Center (an otolaryngologist is most often referred to as an ear, nose and throat specialist).
Like blinking or breathing, sneezing is a semi-autonomous reflex, meaning we exercise some conscious control over its mechanism – we can try to restrain ourselves or submit and start reaching for a tissue.
The act of sneezing itself, technically called sternutation, usually begins as an electrical signal that is triggered by a trespassing particle’s contact with nerve endings in the mucous membranes of our sinuses. This neural message then travels to the brain stem, which is located in the lower rear of our head where the spine connects to the brain and controls rudimentary bodily functions such as respiration and swallowing.
Once the command for a sneeze has reached the brain stem, an all points bulletin” is sent throughout the body’s musculature and a powerful, coordinated contraction takes place. Our eyes are forced closed, and other facial, chest and abdominal muscle groups are recruited as well. Some muscles actually anchor and brace us while in the throes of a nasal outburst to avoid unintended bodily injury.
“They keep us from jet-action, throwing ourselves across the room,” says Banks.
A typical sneeze has a velocity of about 100 miles per hour (160 kilometers per hour), an impressive hurricane squall, while a regular breath idles along at just 5 mph. That 20-fold increase usually serves to eject whatever it is that is causing the offense, but some people have to blast out several sneezes, oftentimes hilariously, before finally getting a well-deserved break.
Scientists have yet to come up with a good explanation for why most people sneeze the predictable two or three times, while others are wracked by staccato attacks. But the answer seems to lie in an individual’s unique immunological and neurological constitution.
“Multiple sneezes are more common in allergenic individuals, especially those with an ongoing chronic stimulus of some sort,” says Banks.
What if you hold in a sneeze? There is the often-repeated fear that an internal backfiring can burst capillaries in the sinuses or eyes, injure the delicate inner ears or even cause a stroke.
Dr. Clark Kaufman, a pediatric allergist in private practice in Lancaster, Pa., thinks this is unlikely. “It’s not dangerous,” he says. “Most people do it all the time and get away with it.” But he cautions that as your body may be trying to dislodge something, it’s probably not a good idea to hold back on a routine basis.
So chances are you won’t do any permanent damage if you quash that sneeze during a job interview or a date. To help suppress the urge, try placing your index finger under your nose.
“This sends sense signals to your brain using the same neural pathways that a sneeze does,” advises Banks. By doing this, you can “overload your neural circuitry” and prevent the sneeze from occurring.
In lieu of putting a finger to the face in a gesture that unintentionally mimics a mustache, Banks also recommends breathing through one’s mouth, as this will decrease turbulence in the nose and may help thwart the impending “atchoo.”
On the other hand, if you have a sneeze that refuses to come out or go away, and you’re grimacing awkwardly in public, close your mouth and inhale through your nose to further excite the nerve endings. This will assist in getting you across the threshold so the sneeze reflex kicks in, and then you can just let ‘er rip.
After all, if Freud is to believed, sneezing is actually sort of sexy – though don’t expect to hear “hubba hubba” the next time you do.

How many muscles does it take to smile?

How many muscles does it take to smile?

Baby and mom both have smiles on their faces, but whose grin takes more effort?

You've likely been told (or read in a forwarded e-mail) that it takes fewer muscles to smile than it does to frown, and that, in light of this fact, you should smile more often. There are quite a few numbers that get tossed around when this line is used. Some claim it takes 43 muscles to frown and 17 to smile, but open Aunt Milda's chain letter and you might be surprised to learn it takes 26 to smile and 62 to frown. And some naysayers claim it's quite the opposite, that in fact it takes more muscles to smile than to frown.
When we make facial expressions, we're essentially transmitting a packet of information that can be received, read and interpreted by others. By contracting or expanding our facial muscles in different degrees and combinations, we can produce thousands of different messages that provide cues to our overall emotional state, our short-term feelings about our immediate environment, our mental well-being, our personality and mood, our physical health, our creditability and whether or not we view others as being creditable.

Skin Anatomy

Skin Anatomy

The skin is composed of several layers. The very top layer is the epidermis and is the layer of skin you can see. In Latin, the prefix “epi-” means “upon” or “over.” So the epidermis is the layer upon the dermis (the dermis is the second layer of skin). Made of dead skin cells, the epidermis is waterproof and serves as a protective wrap for the underlying skin layers and the rest of the body. It contains melanin, which protects against the sun's harmful rays and also gives skin its color. When you are in the sun, the melanin builds up to increase its protective properties, which also causes the skin to darken. The epidermis also contains very sensitive cells called touch receptors that give the brain a variety of information about the environment the body is in.
The second layer of skin is the dermis. The dermis contains hair follicles, sweat glands, sebaceous (oil) glands, blood vessels, nerve endings, and a variety of touch receptors. Its primary function is to sustain and support the epidermis by diffusing nutrients to it and replacing the skin cells that are shed off the upper layer of the epidermis. New cells are formed at the junction between the dermis and epidermis, and they slowly push their way towards the surface of the skin so that they can replace the dead skin cells that are shed. Oil and sweat glands eliminate waste produced at the dermis level of the skin by opening their pores at the surface of the epidermis and releasing the waste.
The bottom layer is the subcutaneous tissue which is composed of fat and connective tissue. The layer of fat acts as an insulator and helps regulate body temperature. It also acts as a cushion to protect underlying tissue from damage when you bump into things. The connective tissue keeps the skin attached to the muscles and tendons underneath.

Fantastic facts about the human body

Fantastic Facts about the Human Body




1. Approximately 80-90% of what we perceive as "taste" actually is due to our sense of smell.
2. Your heart beats about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times.
3. Your body has about 5.6 liters (6 quarts) of blood. This 5.6 liters of blood circulates through the body three times every minute. In one day, the blood travels a total of 19,000 km (12,000 miles)- that's four times the distance across the U.S. from coast to coast.
4. The heart pumps about 1 million barrels of blood during an average lifetime - that's enough to fill more than 3 super tankers.
5. If all arteries, veins, and capillaries of the human circulatory system were laid end to end, the total length would be 60,000 miles, or 100,000 km. That's nearly two and a half times around the Earth!
6. Even though its thickness averages just 2mm, your skin gets an eighth of all your blood supply.
7. The skull looks as though it is a single bone. In fact, it is made up of 22 separate bones, cemented together along rigid joints called sutures.
8. If a human adult's digestive tract were stretched out, it would be 6 to 9 m (20 to 30 ft) long.
9. Red blood cells may live for about four months circulating throughout the body, feeding the 60 trillion other body cells. Red blood cells make approximately 250,000 round trips of the body before returning to the bone marrow, where they were born, to die.
10. Human hair grows about 1/4 inch (about 6 millimeters) every month and keeps on growing for up to 6 years. The hair then falls out and another grows in its place.
11. The average healthy mouth produces about 600 milliliters of saliva each day. That's enough to fill a 12-ounce soda bottle.
12. The fastest nerve cells are carrying messages along their axons at an amazing 130 yards per second (268mph)

Secret of nail

The nail files: 30 things every woman should know

The nail files: things every woman should know

Women rely upon their nails to accessorise any outfit.
Yet they can also attract bacteria and infection - as well as revealing a great deal about our inner health.
Here, we present the secret nail files . . .
1. Nails are mostly made from keratin, a fibrous protein substance also found in hair. Although fingernails may seem brittle and easily broken, in fact because they are 96 per cent proteins, arranged in lengthwise, twisting strands, their structure is 40 times more resistant to fracture than stone.
2. Nails need to be pliable - if they were too tough they would simply split and crack. It is the presence of fat and water molecules between the layers of keratin that makes flexible as well as shiny.
3. The pink part of the nail is known as the nail bed. This contains the capillaries that bring nourishment to the area just beneath the cuticle, known as the matrix. The matrix is where new cells are generated, making nails grow.
The whole nail, from its white tip to its pink bed, is known as the nail plate, and the crescent moon at its base is called the lunula.

Disease from mouth

Discovering what lives in your mouth

Bacteria give clues to cancer and gum disease

our mouth is a great place for micropests to dwell. Glistening white plateaus, dark crevices, and slimy surfaces boast steamy temperatures of 95 degrees Fahrenheit. The microbes bathe in a saliva-induced humidity of 100 percent, and eat a lavish diet of sugar and other carbohydrates. It’s so lush and varied, researcher Donna Mager refers to it as a mini-jungle. Mager is a fellow in oral medicine at the Forsyth Institute, an independent research institution in Boston. Forsyth scientists, most of whom are on the faculty of the Harvard School of Dental Medicine, have found 615 different species of bacteria – and they’re still counting. “In one mouth, the number of bacteria can easily exceed the number of people who live on Earth,” notes Sigmund Socransky, associate clinical professor of periodontology at Harvard. Years of detecting and identifying mouth tenants have revealed that those living in healthy mouths can be remarkably different from those living in diseased mouths. Some bacteria increase in number, while others decrease. By comparing communities of microbes in healthy people with those in the mouths of those with oral cancer, Mager has found a pattern that she expects will lead to the early diagnosis of oral cancers.