²ʲв
:
³
ʳ
'
˳
˳
ϳ
'
㳿
Գ
Գ
Գ
Գ


The Curriculum of Auxiliary Schools

The curriculum of the auxiliary school is based on the principle of correcting education and upbringing. That is why, while all the subjects are within the child's range, they are also intended to make the greatest possible use of his intellectual and physical abilities and to further his development. The older children of the auxiliary school spend closely 40 percent of their study periods in workshop practice. An intensive study, based on the work of the auxiliary schools is now under way. It will determine ways and means for the further pedagogical and psycho-pedagogical assessment of the peculiarities of development of the mentally retarded child; the educational principles and methods in teaching general educational subjects; workshop training, etc. There is an intensive research for new audio-visual and other measures are being introduced to facilitate the learning process. Much is being done in the field of moral education, in studying relationships between the pupils of the auxiliary schools, through group study, work, games, etc.

Schools for the deaf teach a child his native language based on the principle of communication. Everything is done to teach the child to understand direct speech, and the use of finger-spelling is instrumental. The basic means of communication between deaf children during the first stage of their education finger-spelling, as their knowledge of the spoken and written language increases, in time becomes an auxiliary means, which aids in the better assimilation of the spoken language and a more accurate understanding of direct speech.

Unlike deaf children, the hard of hearing child proved to be able, on the basis of an oral understanding of direct speech, to acquire a small active vocabulary as it does not fully articulate the words. Schools for the hard of hearing are to create the necessary conditions for the maximum development of the pupil's limited speech. The curriculum and teaching methods in these schools call for systematic training in the basic components of language (vocabulary, phonetics and grammar). These schools have classes in pronunciation, lip-reading, corrective grammar and sound and letter practice. Individual tutoring is of special importance in developing the child's ability to hear.

One of the stages of this corrective work is preschool training and education, which make it possible to achieve good results in overcoming and preventing secondary defects.

In the past decade finger-spelling has been widely introduced in preschool establishments for the deaf. This has had a definite effect, both on their general development and in forming good speech patterns.

At present, special emphasis is being placed on the all-round clinical study of preschool age children who have hearing disorders, and on developing methods for the earliest possible diagnosis of these disorders. In studying these children, the degree of their impairment is taken into account, as well as their scope of vision, space perception, ability to think, personality and behaviour.

The deaf or hard of hearing child's ability to understand direct speech with the help of visual or tactile analysers has made it possible to draw up a special curriculum and methodological guide for teaching lip-reading and developing the child's hearing.

In reviewing the problems connected with teaching pronunciation, a new approach was developed concerning the influence of phonetic factors on oral speech. These studies have produced a new method of teaching correct pronunciation to the deaf.

Special Schools

At present, there are many special schools for children who are blind, partially sighted, or deaf or hard of hearing.

On the eve of the Second World War all handicapped and retarded children in a number of large cities of the country were fully cared for by the special school system and in many regional and territorial centers this task was close to being realized.

At present blind children and those with severely impaired eyesight, receive a complete secondary education in the course of 12 years of study. Deaf and hard of hearing pupils are given the same period to acquire the curriculum of the eight-year secondary education in 12 years.

Auxiliary schools (for mentally retarded children) with an eight-year term of study provide an elementary education and give children vocational training. There are special evening secondary schools for working adults who are blind, partially sighted, deaf or hard of hearing.

There are also special secondary schools for children with disturbances of motor function and special schools for children who are multiply handicapped.

Preschool establishments for the deaf and hard of hearing, the blind, the mentally retarded and children with speech defects have been developing successfully in the past decades.

Prior to entering school all children who have reached 6 years of age must have a thorough medical examination by a team of specialists at their district children's polyclinic. This examination is compulsory for every child entering school. Children who have serious defects of vision, hearing or speech and who find studying in a normal school too difficult are referred to a special school. These special schools have their own admission boards consisting of a child's psycho-neurologist, a speech therapist, a member of the administration of the special school and, when necessary, an ear, nose and throat or an eye specialist. These specialists do not only examine the child carefully, they analyse his entire case history. Based on this study the board determines the degree of his disability and the type of establishment he is to be referred to.

Schools for the deaf accept children who are completely deaf and dumb, as well as children who react to loud sounds but who do not differentiate between the sounds of speech or can discern only separate vowels. Schools for the hard of hearing accept children who understand normal speech at a distance of no more than 3 meters and who, as a result of defective hearing, subsequently suffer from under-developed speech.

Schools for children with speech defects accept children with grave defects of speech who have normal hearing and are not mentally retarded. At present, everything possible is being done to overcome and prevent speech defects, both in special and in normal schools. The relationship between defects of oral speech and poor progress in learning to write has thus established that the progress a child makes in reading and writing in many ways depends upon his speech development. This knowledge has resulted in a unified system of combating defects of speech, writing and reading. It has been introduced in the school system and has shown good results.

:

 

Insects and Insecticides

The effective control of injurious insects demands knowledge of the habit of the insects themselves, so that they may be attacked at the most vulnerable points.

Insects differ greatly in their habits and life history that is why methods of control also may differ greatly not only with regard to individual insects but also with regard to crops that are attacked by them.

Insects that live mostly in the ground and injure the roots of plants must be controlled in a different way from those that feed on foliage.

Insects attacking the cereal crops cannot be treated in the same way as those attacking the fruit and leaves of garden or orchard crops.

Injuries to vegetable and other crops may be prevented by various cultural preventive measures, such as clean farming and crop rotation. Cultural practice can be relied on in the case of some crops but not of all of them. With most crops artificial or remedial methods must be practised, that is, the application of materials that either poison or kill insects by contact with their tissues.

These substances are known to be insecticides. Artificial methods may be classified as follows: 1) the application of poisons against biting insects; 2) the application of contact substances against sucking insects; 3) the use of poison gases.

When applying insecticides three factors must be taken into consideration: effectiveness against insects, cheapness of the material, and its application and harmlessness to insect hosts. Insecticides may be used in the form of sprays and dusts. Application of the insecticides in the form of a spray requires thoroughness of spraying. Dusting is often practiced too. In some cases, the results of the dust methods are very satisfactory and they give the possibility to protect orchards and fields at critical times. A large orchard can be treated in about one fifth of the time required by liquid spraying.

Insecticides are usually divided into three classes: internal poisons and those that kill by contact and fumigants.

Internal poisons are used against chewing insects and kill by being taken into the digestive tract.

The contact insecticides are not eaten but applied directly to the insect body and produce death in various ways: either by suffocation, by corrosive action, or by fumes that penetrate the breathing pores of the insects.

Until recently the modes of action of insecticides was not well understood. It was supposed that contact substances kill insects by stopping the breathing pores or plugging the tracheae, producing death by suffocation. Recent investigations show that insects are not readily suffocated. The volatile portions of kerosene, carbon, bisulphides, creolin, etc. are effective long before the liquid are absorbed by their tissues.

With the penetration of the volatile substances the nervous system is seriously affected, results resembling narcosis are produced and a disturbance of the respiratory activity occurs. Insect tissues soon become saturated when exposed to the vapours of the substances and death results through the inability of the tissue to absorb oxygen in the presence of these vapours.

The most effective poisons for the destruction of biting insects are Paris green, arsenite of lime, sodium fluoride.

The main substances used as contact insecticides against sucking insects are: lime sulphur wash, soap, kerosene emulsion, tobacco decoction, wiscible oils, pyretrum, lime dust, carbolic acid, emulsion DDT, benzine gexachloride and others.

The main poisonous gases are carbon bisulphide, hydrocyanic acid gas, sulphur dioxide fumes, tobacco, formalin, carbon tetrachlorid and others.

 

Blood Pressure

Blood pressure is a force exerted by the blood upon the walls of the arteries. The pressure in the arteries is initiated by the pumping action of the heart, and pressure waves can be felt at the wrist and at other points where arteries lie near the surface of the body. Blood pressure is strongest in the aorta, where the blood leaves the heart. It diminishes progressively in the smaller blood vessels and reaches its lowest point in the veins.

Blood pressure is dramatically manifested when an artery is severed or pierced, and the blood (under pressure) ejects in spurts. Since the heart can pump blood into the large arteries more quickly than it can be absorbed and released by the tiny arterioles and capillaries, there is always considerable inner pressure in the arteries. The contraction of the heart (systole) causes the blood pressure to rise to its highest point, and relaxation of the heart (diastole) brings the pressure down to its lowest point. Since blood pressure varies in different arteries, the pressure in the brachial artery of the forearm is used as a standard. It is measured in millimeters of mercury by means of an instrument known as a sphygmomanometer. The normal readings in young people are about 120 mm for systolic pressure and about 80 mm for diastolic pressure, commonly written as 120/80 and read as "one-twenty over eighty".

With age, and the constriction of the small arteries and then the larger ones, blood pressure increases, so that at 50 years it is considered normal to have a systolic pressure between 140 and 150, and a diastolic pressure of about 90. Factors other than heart action and the condition of the arteries also influence blood pressure. Temporary high blood pressure usually occurs during or following physical activity, nervous strain, and periods of rage or fear. Therapy for persistent high blood pressure consists of sufficient rest, mild sedation (especially with pressure-reducing drugs), a diet low in salt and protein, and reduction in weight where there is obesity. Low blood pressure (hypotension) is considered to be advantageous if it is not caused by disease or injury.

Anemia is a condition in which the concentration of hemoglobin in the circulating blood is below normal. Such a condition is caused by a deficient number of erythrocytes (red blood cells), an. abnormally low level of hemoglobin in the individual cells, or both these conditions simultaneously. Regardless of the cause, all types of anemia cause similar signs and symptoms because of the blood's reduced capacity to carry oxygen. These symptoms include pallor of the skin and mucous membranes, weakness, dizziness, easy fatigability, and drowsiness. Severe cases show difficulty in breathing, heart abnormalities, and digestive complaints. One of the most common anemias, iron-deficiency anemia, is caused by insufficient iron, an element essential for the formation of hemoglobin in the erythrocytes. In most adults (except pregnant women), the cause is chronic blood loss rather than insufficient iron in the diet, and, therefore, the treatment includes locating the source of abnormal bleeding in addition to the administration of iron. Pernicious anemia causes an increased production of erythrocytes that are structurally abnormal and have attenuated life spans. This condition rarely occurs before age 35 and is inherited, being more prevalent among persons of Scandinavian, Irish, and English extraction. It is caused by the inability of the body to absorb vitamin B12 (which is essential for the maturation of erythrocytes) from food and is treated by repeated injections of vitamin B12.

 

Artificial Fertilizers

The three elements nitrogen, phosphorus and potash are the most valuable ingredients of the soil, for they are found in smaller quantities in proportion to their needs, and are more easily lost than some of the other elements. All other elements, besides these three, have no value except as fillers.

Although each element is essential to plant or animal growth, each of them has a specific function.

Nitrogen promotes leafage in plants. Green, luxuriant growth indicates a sufficiency of nitrogen. Often orchard trees have a great deal of foliage, which shows that an abundance of nitrogen is present in the soil. Phosphorus is found in some of the proteins, and since we find a greater amount of protein in the seeds than in the leaves and stems, it is thought that phosphorus plays an important part in seed formation. This element hastens root and stem growth, and especially seed growth, and for that reason hastens maturity, often an important factor in getting maximum yields. Potassium seems to assist in the formation of starch and sugar. As a consequence of the effect of potassium on leaf, root, and sugar in mangeles, the sugar production is more than double.

In animal bodies, nitrogen helps to make bone, tendons, muscles and other tissues. Phosphorus makes up a large part of the bones, ninety percent of bone content being lime and phosphorus. Potassium too aids in bone formation and other processes.

Kinds of Artificial Fertilizers. Just as there are essential elements in soil fertilizers, so there are, broadly speaking, three kinds of artificial fertilizers. Each is named after the element, which makes up the main ingredient: thus we have nitrogenous, phosphatic and potassium fertilizers.

Nitrogenous Fertilizers. The chief sources of nitrogenous fertilizers are: 1) slaughter-houses; 2) sodium nitrate mines and 3) cottonseed factories. Dried blood, tankage, and steamed bone meal come from the slaughter-houses. It was stated that the cheapest and most effective means of increasing the nitrogen in the soil was by growing legume crops. Occasionally such a crop may be ploughed under for the tops of legumes are richer in plant foods than the roots.

The legumes do not gather enough nitrogen from the air to add an appreciable amount of nitrogen to the soil where these crops are annually removed. Unless some legume is ploughed under, the balance in nitrogen may be maintained by the growing of a legume, but not increased. Consequently, manure, a legume crop, or artificial nitrogen, must be added if the balance of nitrogen in the soil is to be increased.

Phosphate Fertilizers come from phosphate rocks and slaughterhouses. The rocks are ground into fine powder. The product is called "Rock Phosphate". The bones of animals slaughtered in the packinghouses are made into fertilizers. The phosphorus content of these fertilizers ranges from 10 to 25 percent, the average being probably 12.5 to 15 percent soluble phosphorus. The rock phosphates contain from 20 to 30 percent phosphoric acid. The phosphate fertilizers are probably the most important fertilizers, considering their value in growing plants.

To make possible the growth of clover or other legumes and the consequent addition of nitrogen from the inexhaustible supply in the air, it is necessary to maintain or to increase the amount of phosphorus in the soil.

More about Insects

Insects possess an external skeleton composed of a series of segments which is divided into three well defined regions: head, thorax and abdomen. The head bears a pair of antennae, a pair of compound eyes and often three simple eyes or occelli. Three pairs of legs are born on thorax and in the adult condition two pairs of wings can be seen. Some insects have only one. The wings are modified in different ways: in the butterflies, they are covered with scales; in the beetles, the front wings are hard and horny and are known as wing-covers under which the hind wings are folded when in repose. In many true bugs, the front wings are of leathery texture except the tip, which is membranous. In the female, the abdomen is often provided with a sharp ovipositor.

The mouth-parts of insects are adapted for feeding in various ways and on all kinds of plant tissue. There are chewing insects. These are insects such as grasshoppers whose mouth part is provided with a pair of hard horny jaws or mandibles with which the insect is able to bite off portions of plant tissue which are then swallowed.

There are sucking insects, which have the mouth parts modified to form a beak containing four bristles united into a slender tube with which they puncture the tissues of the plant and suck out the juice.

Plant lice and true bugs belong to this group of insects. Some flies belong to the group of lapping insects. The mouth-parts of such insects are developed into a tongue-like organ with which they are able to lap or lick up liquids.

Insects breathe through a series of openings called spiracles extending along the side of the body. These openings connect with tubes called tracheae which subdividing again and again, extend to all parts of the body.

Most insects with the exception of some scale insects and certain forms of plant lice reproduce by means of eggs.

The newly hatched insect usually bears little resemblance to the adult. As it increases in size, its skin becomes too small, a new skin is formed beneath the old one and the latter is discarded. This is called molting. The period between two molts is called an instar. The number of instars varies in different insects from three to six or seven. Five is the more common number.

Some insects have an incomplete metamorphoses. That is, when the change from immature condition to the winged adult takes place without any material change in form. In others the transformation is

Magnesium

Magnesium has long been known as the lightest of our engineering metals. This metal, silvery white in color, has a specific gravity of only 1.74. Aluminum, the next lightest structural metal, is l1/,, times heavier; zinc is 4 times heavier; iron and steel are 4V2 times heavier; and copper and nickel are 5 times heavier. Magnesium does not occur in the free state but is very abundant in nature, constituting 2.5 pet of the earth's crust in the form of various ores. It is the third most abundant structural metal, being exceeded only by iron and aluminum.

Magnesium is unique, however, in that in the form of magnesium chloride it also exists in the oceans. Sea water is the source most widely used for production in the United States but magnesium is also commercially produced from magnesite, dolomite, and other ores as well as from certain inland brines.

Not only is magnesium potentially very abundant but it is in addition a very versatile metal and can be shaped and worked by practically all methods known to the art of metal working. It can be cast by sand, die, and the various permanent-mold methods; extruded into an endless variety of shapes and rolled into sheet, plate, and strip. Magnesium is readily forged and can be formed into useful shapes by drawing, bending, spinning, impact extrusion, and other standard methods. The joining of magnesium is accomplished by gas, arc and electric-resistance welding methods and by brazing, bolting, and riveting. The machinability of magnesium is unsurpassed by that of any other structural metal and magnesium is often selected for an application because of this characteristic. The chemical and electrochemical properties of magnesium also provide the bases for important commercial uses.

Because of the two outstanding characteristics, availability and workability, magnesium is now considered to be destined to become one of the world's common structural metals. This is in contrast to conditions existing only about a decade ago, before sea-water plants had been developed and before common metal-working techniques had been sufficiently adapted to magnesium fabrication.

© 2013 wikipage.com.ua - wikipage.com.ua |