Enamel is a vitreous glaze of various colours fused to the surface of gold, silver, copper, and other substances. The art of enamelling, which is of great antiquity, was practised by the Assyrians and by the Egyptians, from whom it may have passed into Greece, and thence into Rome and its provinces, including Great Britain, where various Roman antiquities with enamelled ornamentation have been discovered. The enamelled gold cup given by King John to the corporation of Lynn, in Norfolk, proves that the art was known among the Normans. The Byzantines of the 10th century produced excellent cloisonne enamels on a gold base, the cloisonne process consisting in tracing the design in fillets of gold upon the gold plate and filling up the small moulds thus formed with enamels the design appearing in coloured enamels separated by thin gold partitions or cloisons. In some cases, however, the enamels were filled into hollows beaten out in the gold plate, which formed part of the field.
In the 12th century the town of Limoges acquired the high reputation for inlaid enamels which it held until the 14th century, aud re-acquired in the 16th for its painted enamels. The costliness of the sculptured ground had led the Italians early in the 14th century to substitute the practice of incising the design on the face of the plate, and then covering it with a transparent enamel. The further step, which made the Limousin workshops famous, consisted in the method of superficial enamelling, in which opaque colours or colours laid on a white opaque ground were used. The Limoges school degenerated greatly in the 17th century, but its method with certain modifications in detail is still employed.
The basis of all kinds of enamel is a perfectly transparent and fusibleglass, which is rendered either semitransparent or opaque by the admixture of metallic oxides. White enamels are composed by melting the oxide of tin with glass, and adding a small quantity of manganese or phosphate of calcium to increase the brilliancy of the colour. The addition of the oxide of lead, or antimony, or oxide of silver, produces a yellow enamel. Reds are formed by copper, and by an intermixture of the oxides of gold and iron. Greens, violets, and blues are formed from the oxides of copper, cobalt, and iron.
In the middle of the 18th century enamelling was largely applied to the decoration of snuff-boxes, tea-canisters, candlesticks, and other small articles. Of later years it was extensively applied to the coating of iron vessels for domestic purposes, the protection of the insides of baths, cisterns, and boilers, and the like. Enamelling in colours upon iron was common, iron plates being thus treated by means of various mixtures, and words and designs of various kinds being permanently fixed upon them by stencilling, for advertising, signboards, etc.
A spa is a health resort at which natural waters or baths can be taken for therapeutic purposes. The name is derived from the town of Spa in Belgium, one of the oldest watering places. Many forms of natural waters exist, suitable for the treatment of various complaints, but the particular characteristics of the water is not the solefactor which gives a spa its therapeutic efficiency. The spas often provided a period of hygienic living to people who otherwise were deprived of it, and this often proved as beneficial as the waters themselves.
In its narrow, everyday use, vegetable is a word indicating any herb that is cultivated specially for table use in whole or part, such as the turnip (root), cabbage (leaves), broccoli (flowers), peas and beans (fruit). In its widest sense it includes all living things that are not animals - trees, shrubs, herbs, ferns, mosses, seaweeds, fungi, and the microscopic diatoms.
The unit of structure, the cell, is essentially the same in both animals and plants, but the combination of the cells into tissues and organs shows marked differences.
All animals depend for their food upon material originally elaborated by plants. The green plants alone have the power to construct this basic food material from elemental substances, and physiological processes different from those of animal assimilation are rendered necessary. The fungi approach the animals in this respect: they must feed upon material that has already done service as part of the structure of other plants or of animals.
The fine divisions of roots explore the soil in search of water in which are dissolved the salts of sodium, iron, potassium, phosphorus, calcium, sulphur, etc. The hairs with which the rootlets are clothed absorb this fluid by osmosis, and it is passed upward through the long vessels of the wood bundles until it reaches the cells of the leaf. These cells contain green bodies (chloroplasts) in their protoplasm, and it is these that impart the green colour to leaves and soft shoots. In the leaf-skin (epidermis) there are innumerable pores or stomata through which surplus water from the roots is evaporated and through which atmospheric air is admitted to the spaces between the leaf-cells.
The chloroplasts in these cells have the power to utilise solar energy in decomposing the carbon dioxide of the air, and the cells retain the carbon, setting free the oxygen. Water from the roots is broken up also into its elements, hydrogen and oxygen, and with these plus carbonstarch is formed. This, converted into grape sugar, is passed from cell to cell to parts of the plant whore it is needed for the production of new cells, wood, bark, leaves, or fruit. Starch is the material from which are made all the organic substances produced by the plant.
The surplus over present requirements is stored up as reserves in seeds, enlarged roots or stems, bulbs, or tubers for renewed growth or floral display at a later season. Waste products are converted into resins, oils/wax, or alkaloids - many of these being of considerable economic value to man. Part of the water stream from the roots passes by osmosis from cell to cell, where it is necessary in order to keep the protoplasm in an active condition; any insufficiency is followed by a flagging of the tissues, the drooping of leaves and young shoots. In addition to the absorption of carbon by the protoplasts for building purposes, the leaf-cells also take up oxygen from the atmosphere and give off carbon much as animals do.
As the plant respires without lungs and assimilates without digestive organs, so also it can effect movements without a muscular system and react to external stimuli without a nervous system. It is sensitive to light and heat; many plants have distinct night and day positions for their leaves. It responds positively and negatively to the force of gravity, the root going down into the earth and the stem rising into the air. The growing tip of a stem or shoot commonly nutates, i.e. moves from side to side or in a circle or ellipse. The plant can orientate itself, i.e. take up a definite position in regard to the incidence of light or other external stimulus. These movements appear to be controlled largely by alterations in the position of the mobile chloroplasts.
The reproductive process is, in essentials, similar to that of animals, the ovules or seed-eggs in the ovary requiring to be fertilised by male sperms represented by the pollen grains produced in the anthers. The result of such fertilisation is to cause the ovule to develop into an embryo capable of further development under suitable conditions into a plant resembling the parent. Research Vegetable
Coral is a vast commune made up of tiny marine organisms called polyps, which are related to sea anemones.
Corals are of two types: perforate and imperforate. Perforate corals have porous skeletons with connections between the polyps through the skeleton. Imperforate corals have solid skeletons. Many corals have different growth forms. They can be plocoid as in Tubastrea coccinea (orangecup coral) and Favia fragum (golf ball coral). They can also be meandroid in which corallites form a series within the same walls, as in the species Dendrogyra cylindrus (pillar coral). Other growth forms include cocoid, spherical shaped and phalecoid, as in Eusmilia fastigiata.
Corals can obtain food in a variety of ways. Reef-building corals rely on the photosynthetic products of zooxanthellae for the majority of their nutrients. However, corals also capture zooplankton for food using their tentacles.
Coral is essential to the world's eco-system as it absorbs vast quantities of carbon dioxide from the water and converts it into calcium carbonate. More carbon dioxide is absorbed by the world's coral reefs than by the rain- forests on land. In 1998 70% of the world's coral was destroyed by a freak weather system, leading to fears that global warming could increase. Research Coral
Egger moths is a name given to members of the family Lasiocampidae, some members of which are also called lappet moths. All the members of the family are densely covered with scales, and in the male the antennae are beautifully pectinated. In all cases the eggs are smooth, sometimes spotted like those of a bird. The mother sometimes covers the eggs with her own hairs. The caterpillars are very hairy, the hair in some instances having irritating properties. The cocoons are compact and closely woven, and in some cases have a thin layer of calcium oxalate on the surface giving them the appearance of an eggshell. Research Egger Moth
Nutrition is the strategy adopted by an organism to obtain the chemicals it needs to live, grow, and reproduce. The term is also applied to the science of food, and its effect on human and animal life, health, and disease.
Nutrition involves the study of the basic nutrients required to sustain life, their bio-availability in foods and overall diet, and the effects upon them of cooking and storage. It is also concerned with dietary deficiency diseases. There are six classes of nutrients: water, carbohydrates, proteins, fats, vitamins, and minerals. Water is involved in nearly every body process. Animals and humans will succumb to water deprivation sooner than to starvation. Carbohydrates are composed of carbon, hydrogen and oxygen. The major groups are starches, sugars, and cellulose and related material (or ' roughage'). The prime function of the carbohydrates is to provide energy for the body; they also serve as efficient sources of glucose, which the body requires for brain functioning, utilisation of foods, maintenance of body temperature. Roughage includes the stiff structural materials of vegetables, fruits, and cereal products. Proteins are made up of smaller units, amino acids. The primary function of dietary protein is to provide the amino acids
required for growth and maintenance of body tissues. Both vegetable and animal foods are protein sources. Fats serve as concentrated sources of energy, and protect vital organs such as the kidneys and skeleton. Saturated fats derive primarily from animal sources; unsaturated fats from vegetable sources such as nuts and seeds. Vitamins are essential for normal growth, and are either fat-soluble or water-soluble. Fat-soluble vitamins include A, essential to the maintenance of mucous membranes, particularly the conjunctiva of the eyes; D, important to the absorption of calcium; E, an antioxidant; and K, which aids blood clotting. Water-soluble vitamins are the B complex, essential to metabolic reactions, and C, for maintaining connective tissue and cell functioning. Minerals are vital to normal development; calcium and iron are particularly important as they are required in relatively large amounts. Minerals required by the body in trace amounts include chromium, copper, fluoride, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, and zinc. Research Nutrition
Erwin Neher is a German cell physiologist. He was born in 1944 at Landsberg in Germany and trained originally as a physicist in Munich and at the University of Wisconsin. While working at the Max Planck Institute of Psychiatry in Munich, he took a year-long sabbatical to work with the physiologist Sakmann at Yale University. He shared the Nobel Prize for Physiology or Medicine in 1991 with Bert Sakmann for his studies on ion channels and beta-endorphin. Neher and Sakmann developed the patch-clamp technique in 1976 to measure the electrical activity of very small portions of cell membranes. This technique revolutionized the study of ion channels.
To perform the technique a glasspipette with a tip diameter of about one micrometer is pressed against a cell and slight suction is then applied to seal the cellmembrane against the pipette. The technique allows the flow of ions through a single channel and transitions between different states of a channel to be monitored with a time resolution of microseconds. Using this method, Neher and Sakmann investigated the effect of beta-endorphin on the membrane of cells. Beta-endorphin is a neurohormone secreted by the pituitary gland and an opiate that has been found to play a clinical role in the perception of pain, behavioural patterns, obesity, diabetes, and psychiatric disorders. Neher and Sakmann demonstrated that beta-endorphin acts not only on nerves in the brain to regulate their secretion of neurotransmitters but also, via calcium channels, acts on the walls of arteries in the brain. Research Erwin Neher
Baron Jons Jakob Berzelius (John James Berzelius) was a Swedish chemist. He was born in 1779 and died in 1848. He studied medicine at Upsala, and after holding one or two medical appointments was appointed lecturer in chemistry in the Stockholm military academy in 1806, and the following year professor of pharmacy and medicine. In 1808 he became a member of the Academy of Sciences at Stockholm, in 1810 director, and in 1818 its perpetual secretary. In 1818 the king made him a noble, and in 1835 a baron. He was also a deputy to the National Assembly.
He discovered selenium and thorium, first exhibited calcium, barium, strontium, tantalum, silicium, and zirconium in the elemental state, and investigated whole classes of compounds, as those of fluoric acid, the metals in the ores of platinum, tantalum, molybdenum, vanadium, sulphursalts, etc, and introduced a new nomenclature and classification of chemical compounds. In short, there was no branch of chemistry to which he did not render essential service. His writings comprise an important Text-book of Chemistry, View of the Composition of Animal Fluids, New System of Mineralogy, Essay on the Theory of Chemical Proportions, etc. He was the founder of electrochemical theory and designed the system of chemical symbols still in use. Research Jons Jakob Berzelius
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Abbreviations
Research Aldebaran
