The 5Ws and H of Science continues…


How much blood do newborns have?

THE important component to keep a human alive is blood. Blood is a liquid found in blood vessels. Blood is made of plasma, red blood cells, white blood cells and platelets. Blood is pumped from the heart to all parts of the body. Bloods helps to distribute oxygen and nutrients to all the parts of the body so they can keep functioning. Blood carries carbon dioxide and other waste materials from the lungs, kidneys, and digestive system to be removed from the body. Blood also fights infections, and carries hormones around the body. The amount of blood in our body differs based on the age group. The total blood volume in body can be predictable based on the age and weight of the child. The total blood volume in newborn babies will contain 80ml per kg of body weight. Babies from 1 to 12 months need about 75ml per kg of body weight. The amount of blood in pre-term babies, is about 90 ml per kg of body weight.

What is anosmia?

IT’S a blessing to have a sense of smell. We can smell the scent of flowers, taste food and detect odours. Have you ever thought about what it would be like if unable to smell something? Anosmia is a complete loss of the ability to detect smells. This condition may be temporary or permanent. Anosmia is usually not serious, but it can have a profound effect on a person’s quality of life. Without the sense of smell we won’t be able to define whether we are in a safe situation or dangerous situation. In certain situations, like a gas leak or smoke from fire, we won’t be able to smell. The most common reason for anosmia in most people is due to a stuffy nose caused cold or allergies. Once, the cold runs its course, a person’s sense of smell returns. Old age may also cause the loss of sense of smell. Apart from that, medical conditions such as brain tumours or head traumas will affect the brain and nerves and cause permanent loss of smell.

How does addiction work?

THE word “addiction” is derived from a Latin term for “enslaved by” or “bound to.” Anyone who has struggled to overcome an addiction understands why. Addiction exerts a long and powerful influence on the brain that manifests in three distinct ways: craving for the object of addiction, loss of control over its use, and continuing involvement with it despite adverse consequences. Addiction changes the brain, first by subverting the way it registers pleasure and then by corrupting other normal drives such as learning and motivation. Addiction is today recognised as a chronic disease that changes both brain structure and function. Just as cardiovascular disease damages the heart and diabetes impairs the pancreas, addiction hijacks the brain. This happens as the brain goes through a series of changes, beginning with recognition of pleasure and ending with a drive toward compulsive behaviour. In nature, rewards usually come only with time and effort. Addictive drugs and behaviors provide a shortcut, flooding the brain with dopamine and other neurotransmitters. Our brains do not have an easy way to withstand the onslaught. Over time, the brain adapts in a way that actually makes the sought-after substance or activity less pleasurable. People who develop an addiction typically find that, in time, the desired substance no longer gives them as much pleasure. They have to take more of it to obtain the same dopamine “high” because their brains have adapted—an effect known as tolerance. At this point, compulsion takes over and the person needs to continue with the substance, not being able to function properly without it.

How good is green tea?

GREEN TEA has been used in various ways, including as a stimulant, diuretic and to help improve heart health. The leaves are steamed or pan-fired unlike black tea leaves in order to prevent the fermentation process. Green tea contains high amounts of polyphenols and powerful antioxidants that have been shown to help fight disease. If you find green tea having a slightly bitter flavour, that’s from the catechins which are a specific type of polyphenols specifically found in green tea. Adding lemon to your tea can help cut the bitterness. Green tea is known to reduce high levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). It is also used to improve mental alertness and thinking, lower glucose levels, lower blood pressure, and to treat many other conditions. Studies have shown that women who regularly drink tea, including green or black tea, appear to have a lower risk of developing ovarian cancer. Green tea extracts have been reported to cause liver and kidney problems in rare cases.

How do photocopy machines work?

THE technology underpinning this ubiquitous piece of machinery came about 75 years ago, when inventor Chester Carlson used static electricity created with a handkerchief, light and dry powder to make the first copy on Oct 22, 1938. Today, most photocopiers use a technology called xerography, a dry process that uses electrostatic charges on a lightsensitive photoreceptor to first attract and then transfer toner particles (a powder) onto paper in the form of an image. Heat, pressure or a combination of both is then used to fuse the toner onto the paper. It is predicted that photocopiers will eventually become obsolete as the use of digital documentation increases; however for now it remains widely used.

What makes a tattoo permanent?

HAVE you ever really thought about the chemistry of tattoos? What exactly is in those inks, and how safe are they? Tattoo application uses a mechanised needle to puncture the skin and inject ink into the dermis or second layer of skin just below the epidermis. The process involves damaging the skin, causes a tiny wound. Your body responds to all wounds by sending macrophagesto close the wound and swallow up any foreign invaders and dispose them in the blood stream. In the case of tattoo ink, he pigment particles are too large for the macrophages to destroy, so they get stuck in the dermis. A tattoo will fade if your immune system ever succeeds in breaking up the pigment particles, yet that is not usually the case. Tattoo inks are solutions comprised of a carrier and a colourant. The carrier is the fluid that is used to transport the colourant to the application location. It may contain glycerin, water, isopropyl alcohol, and witch hazel. Tattoo colourants are typically pigments intensely coloured compounds that can reflect light in the visible region of the light spectrum. Now make you wonder are there very real risks involved with inks and the tattoo process? Yes they do. The most common risk is an infection. Other known adverse reactions are allergic-hypersensitivity and auto-immune reactions, inflammation, and interferences with medical diagnoses and treatment.

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The Petri Dish is malaysia’s first dedicated science newspaper. Through The Petri Dish we aim to engage the public on the latest developments on biotechnology.