Artificial blood is a colloidal substance, an emulsion carrying a compound of oxygen, electrolytes, plasma expander and some other compounds that act as a buffer. The plasma expander gives volume to the blood. The demand for blood for clinical purposes led to the development of artificial blood. Decades of research led to the discovery of an alternative to human blood by genetic engineering. This genetically engineered hemoglobin (blood) is known as rHB 1.1. It is produced by the process of fermentation and purification of cultivated genetically engineered E.Coli bacteria.
rHB 1.1 is thirty times more effective in the supply of oxygen than natural blood. The risk of contracting dreadful disease by blood transfusion is completely eliminated by the use of artificial blood and it also has a long storage life.
Saturday, January 29, 2011
Do Birds Sleep? Why Do They Not Fall Off Their Perches?
Yes birds do sleep and some do it standing on one leg. It is an arrangement of tendons that keeps the bird from falling off its perch. There is a tendon known as the flexor tendon from the muscle in the thigh that goes down to the leg, around the ankle and then under the toes. At rest, the weight of the bird makes the bird to bend down on its knees, tightening the tendons and closing the claws. That is why they do not fall of their perches.
Not only do birds sleep they can even be hypnotized into falling asleep by bringing our eyes close to the bird's cage and slowly closing our eyes pretending to fall asleep. The bird will follow suit and fall asleep. You can also make a bird in a cage go to sleep by simply covering its cage. This is because birds rely on sight and with the exception of nocturnal birds, bedtime is when it gets dark.
Not only do birds sleep they can even be hypnotized into falling asleep by bringing our eyes close to the bird's cage and slowly closing our eyes pretending to fall asleep. The bird will follow suit and fall asleep. You can also make a bird in a cage go to sleep by simply covering its cage. This is because birds rely on sight and with the exception of nocturnal birds, bedtime is when it gets dark.
Friday, January 28, 2011
How Do Trees Reduce Air Pollution?
Pollution is prevented by plants in many ways. The atmosphere contains many elements the ratio of which keeps changing from time to time due to our activities such as changes in land use, afforestation, deforestation and the burning of fossil fuels. This results in the production of large quantities of carbonmonoxide, aerosols, dust and methane.
Trees act in many ways to reduce pollution in the atmosphere by acting as a sink for carbonmonoxide. The process of photosynthesis synthesizes carbohydrates using the carbon monoxide in the atmosphere, sunlight and water. The resulting oxygen is sent into the atmosphere which living organisms need.
The atmosphere is also cooled by plants by a process known as transpiration where water vapor is released into the atmosphere.
Dust particles and aerosols settle on the dense foliage of the trees and as such as act as curtains and barriers.
Thursday, January 27, 2011
Why Do Raw Fruits Like Banana Ripen Faster When Kept In Rice Tins?
As already explained in a previous blog ripening is senescence or biological aging. And during this process a large quantity of ethylene is produced. When fruits are placed in an airy place there is the possibility of the ethylene produced getting lost in the air and thus these fruits ripen at a lower, normal pace.
The production of ethylene and the response of the fruit to the excess ethylene happens only when the fruit reaches a certain physiological age.
When unripe fruits are confined in a tin of rice or a sack, the time required to attain this critical stage of biological aging is shortened. The ethylene produced is also confined in the tin or sack and thus diffused more rapidly through the tissues of the fruit and the fruit ripens rapidly.
The banana fruit release a comparatively larger amount of ethylene than other fruits and it has been noticed that other fruits ripen faster if they are placed in a bag along with bananas.
The production of ethylene and the response of the fruit to the excess ethylene happens only when the fruit reaches a certain physiological age.
When unripe fruits are confined in a tin of rice or a sack, the time required to attain this critical stage of biological aging is shortened. The ethylene produced is also confined in the tin or sack and thus diffused more rapidly through the tissues of the fruit and the fruit ripens rapidly.
The banana fruit release a comparatively larger amount of ethylene than other fruits and it has been noticed that other fruits ripen faster if they are placed in a bag along with bananas.
How Do Fruits Ripen?
Senescence or biological aging of plants is associated with the ripening of fruits. It is influenced by the hormone ethylene and involves changes in acidity, color, flavor, texture and content. The production of ethylene increases nearly a hundred times.
When the ripening of a fruit begins, it involves a climacteric change ( a stage of fruit ripening associated with the production of ethylene and increased cell respiration). It sets off a series of biological changes such as lateral growth and loosening of cell walls. Fruits such as bananas, melons, apples, apricots and tomatoes. There are other fruits that are non-climacteric such as citrus, grapes and strawberries. These non-climacteric fruits do not require the production of additional ethylene nor do they have respiration bursts.
Color changes are due to the synthesis of carotenoids (organic pigments) and result in yellow or red color. Other compounds such as anthocyanins that give a fruit a red, blue or purple color depending on it pH value.
Textural changes are due to the limited degradation of cell walls and the activity of enzymes such as polygalacturonase and pectinesterase which plays an important role in the ripening of fruits.
Acidity in plants are due to the presence of citric acid (gooseberry, peaches and tomatoes), malic acid (plum, cherry, banana, apricot and apple) and both of these acids in grapes.
When the ripening of a fruit begins, it involves a climacteric change ( a stage of fruit ripening associated with the production of ethylene and increased cell respiration). It sets off a series of biological changes such as lateral growth and loosening of cell walls. Fruits such as bananas, melons, apples, apricots and tomatoes. There are other fruits that are non-climacteric such as citrus, grapes and strawberries. These non-climacteric fruits do not require the production of additional ethylene nor do they have respiration bursts.
Color changes are due to the synthesis of carotenoids (organic pigments) and result in yellow or red color. Other compounds such as anthocyanins that give a fruit a red, blue or purple color depending on it pH value.
Textural changes are due to the limited degradation of cell walls and the activity of enzymes such as polygalacturonase and pectinesterase which plays an important role in the ripening of fruits.
Acidity in plants are due to the presence of citric acid (gooseberry, peaches and tomatoes), malic acid (plum, cherry, banana, apricot and apple) and both of these acids in grapes.
Why Does An Apple Turn Brown On Being Cut?
There is iron in an apple in the form of ferrous ions which can easily oxidize into ferric compounds. This ferric compound is brown in color. When an apple is cut, its surface is exposed to the oxygen in the air and the ferrous ions get oxidized and convert into ferric compounds resulting in the surface turning brown.
Why Does Jasmine Bloom Only Night?
The blooming of flowers is due to non-directional responses to stimuli such as temperature, humidity and light irradiance and is known as "Nastic Movement". This movement usually takes place in the flat part of the plant that is oriented relative to the body of the plant. It typically takes place in petals and leaves that are bilaterally symmetrical.
Environmental changes send signals to the plant resulting in a differential growth between the lower and upper surfaces of the petals resulting in the blooming of flowers at different times of the day.
In the case of the jasmine flower, this response takes place at night fall due to change over from brightness to darkness. And as such the jasmine flower blooms only at night.
Environmental changes send signals to the plant resulting in a differential growth between the lower and upper surfaces of the petals resulting in the blooming of flowers at different times of the day.
In the case of the jasmine flower, this response takes place at night fall due to change over from brightness to darkness. And as such the jasmine flower blooms only at night.
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