Pregnant women like eating raw mangoes and tamarind. .

Craving for unusual food is considered as the first sign of pregnancy. In reality, although some women do get strong cravings, many do not. No one knows for sure what causes food cravings. Many women find that their senses of taste and smell are changed by pregnancy. For example, some women experience an odd metallic taste in their mouths very early in pregnancy (may be the first sign of pregnancy for an ‘experienced’ mother); others find that taste and smell are dulled. It is possible that these changes affect food likes and dislikes. Some people think that cravings happen in response to temporary deficiency of specific nutrients.

There is probably some truth in this, but it is not the whole story. We only need minute quantities of each vitamin and mineral-certainly not enough to justify a continual craving for just one food. for some women, food cravings may be a conscious or subconscious response to emotion. They may crave a favourite childhood food, or a food that is of special significance to their religion or culture. Cravings for unusual food may also be a private way of marking the special state of being pregnant. Rather than develop a food craving, many women find they suddenly go off certain foods or drinks like fried foods and coffee.

This is often related to pregnancy sickness, but may also be the body’s way of ensuring that they eat and drink wisely. Generally, there’s no harm in giving into food cravings, especially if doing so helps getting through phases like early morning sickness which can be pretty distressing. However this must be done in moderation. Eating a lot of one food only means eating less of other foods and therefore running the risk of becoming deficient in important nutrient. A craving for non-food item-such as ash or soap or toothpaste-is known as ‘pica’. Pica is potentially very harmful if indulged in and must be resisted. Also, substances like soaps and ash may prevent the absorption of nutrients and other food substances.

Technorati Tags: Pregnant,food,deficiency,truth,mineral,emotion,religion,culture,drinks,moderation,Pica,absorption,foods,substances,women,pregnancy,nutrients

Human papilloma virus

The viruses that contain DNA as their genetic material and can induce tumors are called DNA-tumor viruses. They are placed under Papova virus group. Papilloma virus is one type of Papova virus. They cause papillomas or warts of cutaneous and mucosal epithellia in human and other animals, therefore they are called Papilloma viruses. They are nearly 60 sub-types in the warts caused due to human papilloma virus. Transmission is by contact with virus either in living skin or in fragments of shed skin. Genital warts frequently spread by intercourse and perianal warts may reflect homosexual activity. There appears to be a close, if not causative, relationship with genital warts, especially due to HPV type 16 and 18 and carcinoma of the cervix. Nearly 80 per cent of cases with cervical carcinoma harbour one of these viruses. Cervical carcinoma is most common among women with several sexual partners. It is suspected that penile cancer is also due to these types of papilloma viruses.

Technorati Tags: Human,virus,Papova,Papilloma,animals,Transmission,fragments,Genital,intercourse,relationship,cases,Cervical,cancer,viruses,warts,carcinoma

Can Mosquito carry the AIDS causing virus?

Acquired Immune Deficiency Syndrome (AIDS) is caused by Human Immunodeficiency Virus (HIV). The Presence of HIV in blood, semen and vaginal secretion of infected people promotes the spread of the infection through sexual contact, exposure to contaminated blood and blood products. The virus can also be transmitted to the child from the mother. There is no concrete evidence to show that it is transmitted through insect bites.

However HIV does not replicate in mosquitoes. Scientists at centre for Disease control, Atlanta have proved that even in mosquitoes injected with HIV contaminated blood, the virus survives only for one hour. Further, studies on epidemiology of AIDS have provided no evidence linking mosquitoes with disease.Mosquitoes do transmit diseases like Malaria. In the case of AIDS they act as biological vectors and a certain period of time has to elapse for the parasite to become infective. The vector can transmit the infection only after the infectious agent undergoes a developmental process or multiplies in its body.

Is sucking a cut finger, good?

Saliva which is secreted in the oral activity contains many substances which have antibacterial and antiviral activity. These include immune globulins such as IG-A, G, M which help clump the bacteria. Also there are lysozymes which destroy the bacterial cell wall. A protein lactoferrin found in the saliva also help in inhibiting multiplication of bacteria by interfering with iron utilization by the germs. The physical effect of sucking out the infecting material implanted during the cut also plays an important role. Forcibly bleeding the finger and flushing it with running water is equally effective in prevention of bacterial contamination. Even though the biochemical contents of saliva are good, the microbiological contents are not. The oral cavity has been recognized as an area of dangerous microbial contamination and exposing the skin with a cut to such an environment might be inviting trouble.

Why Black Stripe is bordering a color TV screen?

The black bordering is the envelope of the picture tube. The picture tube has to withstand the high atmospheric air pressure, because the glass envelope is evacuated. In older TVs, a special glass or plastic shields were placed before the picture tube to protect any glass from hitting the viewer in case of an implosion. But modern TVs incorporate implosion protection without any shield. In one arrangement a metal rim band called kimcode is held around the tube by a tension strap. The black bordering is nothing but this metal band for implosion protection, which prevents the glass from spilling over if the implosion happens.

How Rainbow colors have seen on CD?

Display of colors by a CD can be understood in terms of the working of a plane optical reflection grating. It is a flat optical device whose surface is ruled/striped with a set of closely and uniformly spaced lines, such that light is reflected by the gaps and absorbed by the lines. When light falls on a plane reflection grating, it is scattered in all directions by each of its reflecting stripes.

These waves from individual gaps are termed wavelets. When we look at the grating from a distance, wavelets from different stripes travel different distances to reach the retina of our eye. Their crests do not reach a given point at the same time. Usually crests of some wavelets and troughs of others reach a point. troughs have the property of partially or totally nullifying crest and vice versa, depending on their strengths. In this case the wavelets are said to interfere destructively.

But for certain orientations of the grating, it so happens that troughs of all wavelets reach a point together, enhancing the effect of each other. The wavelets are then said to interfere constructively. Ordinarily, when light falls on a grating, wavelets corresponding to all wavelengths are sent out by the reflecting gaps. Since the conditions of constructive interference hold good only for some particular wavelength, light intensity at the receiving point is exceptionally high only for that wavelength. Light from the grating from the related direction is thus rich in the corresponding color. Similarly light from slightly different direction is rich in another color. A CD has a data recording track, which spirals from its outer periphery to the inner circular boundary. This takes many tens of thousand rounds about the CD's center.

When examined along a radius of the CD, it is found to have a structure similar to that of a reflection grating- a set of almost straight tracks running perpendicular to the radius and separated by gaps. Therefore, like a grating the CD also displays colors.

Euro norms

Euro norm are meant for regulating vehicular emissions in Europe. The norms are expressed in terms of the weight of pollutants such as carbon monoxide (CO), hydrocarbon, oxides of nitrogen (NOx) and particulate matter emitted per kilometer of vehicular run with load. These ceilings have been fixed for various categories of vehicles. For instance, there are emission levels for petrol-driven and diesel-driven vehicles based on the capacity of the engines. The pollution measurements under engine idling conditions without application of load on the vehicles does not reflect the exact quantum of various pollution emitted by the engines in reality.

In any internal combustion engines, as the speed or acceleration is increased, the time allowed for combustion of the fuel is varied than the idling condition. This variation is different in a carburetor engine and in a fuel injection petrol or diesel engine. In a carburetor engine, the CO will be maximum at idling speed. In a diesel engine, the smoke will be maximum upon sudden acceleration. The Euro norms adopt certain specified driving cycles related with time Vs speed. During these cycles of operation of the engine, the mass of each exhaust gas component is evaluated. The mass is exhaust gas volume. Exhaust gas is generated when the vehicle is operated on a chassis dynamometer according to certain standard driving cycles which stimulate driving conditions in urban traffic.

Why warm up is need before playing physically?

Warming of body raises temperature from 1 to 2◦F, in order to reduce the viscosity of muscle to have better mobility, range of motion, stretch reflexes for better power in muscle and cardiorespiratory adjustment of supply of blood, oxygen and glucose as per demands of effort during playing. The warm-up exercises include rolling, stretching, flexing and agilitic movements to develop coordinated complex movements of neuromuscular function (mechanism of reciprocal stimulation and inhibition). This thereby, prevents incidence of injury of musculo-skeletal structures, improve efficiency of muscular effort (ergonomics). Lack of adequate warming up before playing develops bodily and psychological problems.

Can we fry food with water instead of oil?

We can not. boiling point of water is lower than oil. Food materials contain water in an occluded form or as water of hydration. We fry food essentially to remove this water. For this, the food needs to be heated beyond the boiling point of water (100 deg Celsius). If we use water as the frying medium, the water from the food cannot be removed as the medium itself gets vapourised. However, oil can be heated to more than 150 deg Celsius without charring the food. Being nonvolatile at this temperature, heat from the oil facilitates frying.

Why do lemon drops make white spots on the floor?

Lime juice contains 6-10% of citric acid. Cement is a complex mixture of calcium silicate and calcium aluminates. When drops of lime juice fall on the floor, a chemical change takes place. One of the products is calcium citrate which gives a white colour on these spots.

Ants can find their way to hidden sweets...

Antennae, the two hair-like structures on the head of the ants, help them in locating sweets. These chemoreceptors help them to perceive smell and taste through minute sensilla, or sensory cells. These sensilla can detect accurately the smell in the air. It points towards the origin of the smell by detecting accurately the changes in the concentration of the odoriferous particles. If the sweet are wrapped in paper bags or any other wrappers having minute holes, the odour carried by the air will be sensed by the sensilla. If the antenae are removed, ants cannot identify the smell and distinguish them from other foods.

Is identical twins have same fingerprints?

It is believed that the development of a unique fingerprint ultimately results from a combination of gene-environment interactions. One of the environmental factors is the intrauterine forces such as the flow of the amniotic fluid around the fetus. Because identical twins are situated in different parts of the womb during development, each fetus encounters slightly different intrauterine forces from their sibling, and so a unique fingerprint is born.

Mechanism of Remote control in TV

In earlier days, remote controls were based on Ultrasonics. The controlling circuitry included a hand held transmitter and a TV-based receiver circuit. Electronic filters and stepper motors were used to allow/select certain frequencies and perform various functions depending on the key pressed. But the recent remote controls use Infra-red rays and a special binary coding mechanism. The code, intensity and wavelength of the IR wave, help to select different functions. Depending on the key pressed, a signal is sent out by IR source, say, an injection laser diode (ILD). IT generates a code in a parallel format. This is converted to a series format by a shift register. This signal is received by photo-sensitive devices such as an avalanche photo diode at the receiver. Here another shift register is used to convert the code back to a parallel form. This operates a one-of-n-decoder, which selects one function from a set of 'n' predefined functions and executes it.

Fire is Hot?

Chemical reactions can be either exothermic (heat liberation) or endothermic (heat absorption). Oxidation reactions are exothermic and reduction reactions are endothermic. Combustion is an oxidation reaction and hence is exothermic. All liquid, solid and gaseous fuels contains any one of the three combustibles constituents viz, carbon, hydrogen and sulphur. When a fuel is burnt the heat liberated makes the products of combustion hot. The products of combustion are carbon dioxide, water vapor and sulphur dioxide. Along with these, the unused oxygen in the atmospheric air supplied for combustion and also the entire quantity of nitrogen which is the major constituent in the air are also heated. That is why fire is hot.

Why we feel sleepy while reading?

Feeling sleepy while reading for many is due to the posture in which they read. While reading a person rarely moves, this lack of physical activity causes decreased blood flow to muscles, which results in accumulation of lactic acid (a product of incomplete combustion in the cells). This lactic acid is a highly reducing or oxygen absorbing agent, which quickly reacts with oxygenated blood. This ensures lack of oxygenated blood flowing to the brain, which makes is feel sleepy. To tackle this problem we must avoid reading in a single stretch, instead its better to take some breaks and indulge in physical activity at short intervals.

We become unconscious when hit on the head

The brain is made up of millions of delicate nerve cells suspended in a clear cerebro-spinal fluid which acts as a partial shock absorber, encased inside the skull. It controls all our activities. When the head is injured in an accident the brain absorbs the force and results in a total black out and the person loses consciousness. On regaining consciousness the person will appear to be dazed and confused. this condition is temporary and termed as 'concussion'. However on receiving the blow the thick muscular flap covering the entire brain substance termed 'dura' starts to bleed or swell, then the person may become unconscious as it compresses the brain. This depends on the impact of the hit and the extend of the damage caused to the brain. This condition is termed as 'insuccession'. Noted symptoms of insuccession are: blurred vision, headache and pain in the neck region, frequent giddiness, vomiting and loss of consciousness.

Sweating before heavy rain...

Sweating, also called perspiration, is a continuous process. As the sweat glands, present below the skin, secrete sweat, it evaporated into the atmospheric air depending on the humidity (moisture content) of the air. If the air is dry (low humidity) the evaporation is fast. But, before rain, the atmospheric air is saturated with water vapour and so the evaporation of sweat slows down. As a result the sweat accumulates on the skin giving us a feeling that we sweat more.

What is the principle of breath analysers to detect drunken-driving?

Breath analyser is a device used by police to test drivers suspected of being drunk. This device use the reduction-oxidation reaction. A sample of the driver's breath is drawn into the breath analyser, where it is treated with an acidic solution of potassium dichromate. The alcohol (ethanol) in the breath is converted to acetic acid. In this reaction the ethanol is oxidised to acetic acid and the chromium in the orange-yellow dichromate ion is reduced to green chromic ion. The alcohol level in the blood is determined readily by measuring the degree of the color change from orange-yellow to green, read from a calibrated meter in the breath analyser.

What is Polaroid Sunglass?

Polaroids are thin and large sheets of crystalline polarising material capable of producing plane polarised beams of large cross section. In 1852, it was discovered by researchers that synthetic small needle shaped crystals of iodosulphate of quinine possess the property of polarizing light. These crystals are not stable. A polaroid sheet is prepared from the suspension of these crystals of nitrocellulose. To impart stability, its thin sheet is mounted between two sheets of glass or celluloid.

It can also be obtained by stretching a thin sheet of polyvinyl alcohol strained with iodine. When such a sheet is subjected to a large strain, the molecules get oriented in the direction of applied strain. If the Stretched sheet of polyvinyl alcohol is heated in the presence of a dehydrating agent such as hydrochloric acid, it becomes strongly stable. Each polaroid sheet is enclosed between thin glass plates so as to provide mechanical support.

Polaroids are of two types. H-polaroid and the k-polaroid. The main difference is that k-polaroid are not strained with iodine.

What is the mechanism of Microwave oven?

Microwave ovens cook with the radiation similar to radar waves. In an ordinary oven, heat first hits the outside of the food and works its way inward. But in microwave oven, radiation goes through the food, bounces off the floor or wall of the oven and goes through the food again. The radiation changes its polarity or its '+'ve and '-'ve direction several billion times a second. The rapidly oscillating microwave radiation acts on the water in food because of a special property of water, ie. water molecule has a '+'ve and '-'ve end - Oxygen and Hydrogen. Every water molecule responds to the reversal of microwave field by reversing itself, twisting back and forth billions of times a second. By the twisting water molecules rub against other molecules, they generate friction, which causes the food to heat up and cook rapidly.

Artificial Blood...

Artificial blood is an emulsion of an oxygen carrying compound, a colloidal substance, plasma expander, electrolytes and a few other buffer compounds. The huge demand for human blood for patient care has led researchers to develop artificial blood. The research (which dates back to the Fifties) is focussed on human recombinant haemoglobin and perfluorocarbons. The artificial haemoglobin rHb 1.1 has oxygen binding characteristics similar to that of HbA in red blood cells. Using recombinant DNA technology rHb 1.1 can be produced in required quantities. Perflurocarbons also dissolve a greater amount of oxygen than RBCs. Its solubility for carbon dioxide is three times that for oxygen. These blood substitutes have different boiling points, molecular structures and gas solubilities. Once they are used up, they form colourless, odourless and stable compounds which can be safely expelled.

Sneeze

Sneezing is a reflux mechanism initiated by irritation on the nasal outer membrane. The irritants stimulate pain fibres in the trigeminal nerve supplying the nasal epitheleum, which transmit afferent nerve fibres the medulla oblongata. Efferent nerve fibres from the medulla oblongata initiate a strong inspiratory effort where in about 2.5 litres of air is inspired. This is followed by strong contraction of the respiratory muscles (including abdominal muscles) building up a high intrapulmonary pressure of about 00 mm Hg. This leads to an explosive outflow of air at velocities reaching upto 965 km/hr.

Is animals having mole like human?

A mole is nothing but, melanin pigments deposited on the inner layer of skin (dermis), also called as nevus. It is congenital. Sometimes hairs grown on them. The mole may appear suddenly or existing one change it's color and size. These changes may be an indication of cancer. Melanin pigments are found in all animals, especially in mammals. Because of hairs, moles are not seen distinctly.

Why doctors instructed to take some medicines after food and some before food?

Medicines absorbed into our body system by interfering with food. So the amount of drug that enters the blood and reach the site of action is altered. Based on this mode of action doctors prescribe them to take before or after.Some drugs may be known as not to cause any side reaction when taken in empty stomach and can be fully absorbed by blood stream. This kind of drugs to be taken before food. Some medicines should be taken along with warm plain water, to avoid any reaction between components in milk, curd or tea. But, most of the drugs are advised to take after food. Because it may irritate the stomach by increasing the acid secretion leads to discomfort or pain, chest burning, nausea and vomiting. To avoid these, drugs should be taken after food.

How apple turns to brown on being cut?

The enzyme polyphenol oxidase makes this change. On being cut only, the enzyme is activated by contact with air. The enzyme reacts with carbohydratee in the fruit and form brown color on the cut surface. If cut apple is immersed in an ascorbic acid, this color change will not happen. Because the ascorbic acid inhibits the activity of enzyme. Another one reason: Iron is present in apple in the form of ferrous ions. When cut apple is exposed to air ferrous ion is oxidised to ferric ion which is brown in color.

About Wisdom Teeth...

Third molars or Wisdom teeth usually do not appear until after the age of 17 because until then there is not enough room in the Jaw to allow their growth. Sometimes, even in adulthood, there is not enough room for third molars, whih is why many people have them removed. Indeed, only a minoriy of the population have properly developed third molars in good alignment.

How can we decrease the melting point of ice?

The way is by adding salt. A substance dissolved in a liquid lowers the freezing point or melting point of that liquid. When salt is added to ice at room temperature, some of the ice melts and cools the salt to zero degrees Celsius. The salt solution thus produced cannot remain in equilibrium with ice at zero degrees. It is possible only when the ice at the freezing point of the solutions melts taking the necessary latent heat o fusion from the salt solution, whose temperature is consequently lowered. More salt thus dissolves, keeping the solution saturated and the process continues till the temperature of the solution is reduced to -21 degree Celsius. Only at this point, ice is in equilibrium with saturated salt solution. When 23 per cent of salt is added to ice, the freezing point is lowered to -21 degree Celsius.

Boiled Water lose taste. Why?

Natural water contains a few substances (gases, oxygen and Carbon-dioxide, Sulphates, iron, Carbonates of Calcium and Magnesium) dissolved in it. This constituents make not only taste but also hardness to the water. When boiling the water, the dissolved gases are released and hardness is removed. Some insoluble substances such as carbonates and hydroxides are formed which get deposited on the surfaces and the bottom of the vessel as scales. This separation from water deprives its taste.

Why Vehicle tyres are not filled with water?

Tube-Tyre

When vehicle moves on uneven roads, the tyres filled with air absorb the shocks and make the ride comfortable. Fundamental property of air is compressibility and it enables he shock absorbing capacity. Air gets easily compressed to smaller volumes on application of pressure. Against this, water is not compressible. Hence, the shock generated on the tyres will be passed on to the vehicle leads to discomfort. In addition, wate filled tyres increase the rolling resistance of vehicles because of its weight. So a part of the engine's power and fuel is wasted to overcome this resistance.

Why Cough syrups are mixed by alcohol?

Cough syrups are composed of menthol and natural extracts, for carminative and antitussive actions. Some Natural extracts are water-insoluble, so alcohol is used as a solvent. Hydroxyl group (R-OH) of alcohol increases miscibility via inter molecular hydrogen bondin with solute particles. This enhances the syrup to be absorbed easily by the body. In addition menthol used as a preservative in pharmaceutical preparations to prevent microbial growth, stabilisers by preventing coagulation of solute particles during storage.

Is there any possibility to get cancer in the heart?

Rarely, cancer occurs in the heart aslo.Two classification are there: 1. benign(non-cancerous) and 2. malignant (cancerous). Malignant tumors are classified as primary tumors and secondary tumors. Primary tumors are arising from an organs and secondary tumors are spread from other organs by irect extension or by tumor particles carried through blood and lymphatic stream and get deposited in new organs.

Cardiac tumors are arise from the wall of heart chambers and from the heart muscle. Analytical studies show that 75% of heart tumors are benign and the remaining 25% are malignant. Benign tumors of the heart are Myxoma (40.8%), Lipoma (14.1%), Fibroelastoma (13.2%), Rhabdomyoma (11.3%), Fibroma (5.3%) and heamangioma (4.7%).  Likewise, Malignant tumors of the heart are Angiosarcoma (31.2%), Rhabdomyosarcoma (20.8 %), Mesothelioma (15.2%), Fibrosarcoma (11.2%) and Lymphoma (5.6%).

Secondary malignant tumors can spread through the blood stream to the heart from the kidneys, uterus, stomach, colon and lungs. Direct extension of the tumours from the lung to the heart can also occur. After complete removal of the benign tumors under open heart surgery, the cure rate is almost 100%, whereas the success rate is limited in malignant tumors depending upon further spread of this tumor to other vital organs.

Common Fever...

When the fever is frequent and spread widely such fever is called common fever. The fever differs in different regions: Malarial fever, fever due to presumed viruses and typhoid are common in tropical regions. Symptoms of fever are bodyache, headache and shivering. Bout of shivering followed by sweats and the fever comes down. This entire cycle repeats itself daily or an alternate days.When the season changes, viral fever is accompanied by cold and couh or by transient rash and may be confused with measles. Headache, bodyache and rigors can accompany the fever. Typhoid is a common fever when summer season comes. It due to unhygienic sanitary conditions, drinking unclean water or eating unclean food.The pathogen, Salmonella typhi is responsible for this fever. The symptoms of typhoid fever are loss of appetite, abdomen in the pain, skin rash, constipation and diarrhoea.

How insects enter into Mangoes?

The Scientific name of mango nut weevil is Sternochetus mangiferae Fabr. When Mango fruit in tender stage the weevil puncture the mango and lay about 12-30 eggs. These punctures turns to black or brown marks on the skin. The gum-like substance is secreted and oozes out of the puncture and cover the eggs. These punctures heal in due course as a result of fruits' rippening.

Sometimes, the black marks can be seen even on ripe fruits. From egg to larvae, in a week, larvae is legless. They tunnel through the developing unripened pulp and enter the tender nut which is soft. The nut hardens when fruit matures. The larvae thrive on the cotyledons of the nut. they pupate there after 21 days and dark brown adult emerge. Their life cycle is 35-50 days. Rarely, the adult weevil comes out. So their attack increases the number of fallen fruits. The weevil uses the oxygen present in the fruit for respiration. Thee beetle generally attacks soft-pulped varieties such as neelam, rumani and padhiri.