Wednesday, 20 March 2013

Brain tumor

A brain tumor, or tumour, is an intracranial solid neoplasm, a tumor (defined as an abnormal growth of cells) within the brain or the central spinal canal.

Brain tumors include all tumors inside the cranium or in the central spinal canal. They are created by an abnormal and uncontrolled cell division, usually in the brain itself, but also in lymphatic tissue, in blood vessels, in the cranial nerves, in the brain envelopes (meninges), skull, pituitary gland, or pineal gland. Within the brain itself, the involved cells may be neurons or glial cells (which include astrocytes, oligodendrocytes, and ependymal cells). Brain tumors may also spread from cancers primarily located in other organs (metastatic tumors).

Any brain tumor is inherently serious and life-threatening because of its invasive and infiltrative character in the limited space of the intracranial cavity. However, brain tumors (even malignant ones) are not invariably fatal, especially lipomas which are inherently benign. Brain tumors or intracranial neoplasms can be cancerous (malignant) or non-cancerous (benign); however, the definitions of malignant or benign neoplasms differs from those commonly used in other types of cancerous or non-cancerous neoplasms in the body. Its threat level depends on the combination of factors like the type of tumor, its location, its size and its state of development. Because the brain is well protected by the skull, the early detection of a brain tumor occurs only when diagnostic tools are directed at the intracranial cavity. Usually detection occurs in advanced stages when the presence of the tumor has caused unexplained symptoms.

Primary (true) brain tumors are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain.

history of chrysanthemum

Chrysanthemums were first cultivated in China as a flowering herb as far back as the 15th century BC.[2] The plant is renowned as one of the Four Gentlemen in Chinese and East Asian art. The plant is particularly significant during the Double Ninth Festival. The flower may have been brought to Japan in the eighth century AD[citation needed], and the Emperor adopted the flower as his official seal. The "Festival of Happiness" in Japan celebrates the flower.

The flower was brought to Europe in the 17th century[citation needed]. Linnaeus named it from the Greek word χρυσός chrysous, "golden" (the colour of the original flowers), and ἄνθεμον -anthemon, meaning flower.

Chrysanthemums entered American horticulture in 1798 when Colonel John Stevens imported a cultivated variety known as 'Dark Purple' from England. The introduction was part of an effort to grow attractions within Elysian Fields in Hoboken, New Jersey.[3]

Sunday, 3 March 2013

Huayna picchu

Huayna Picchu also known as Wayna Picchu (Quechua: "Young Peak") is a mountain in Peru around which the Urubamba River bends. It rises over Machu Picchu, the so-called lost city of the Incas, and divides it into sections. The Incas built a trail up the side of the Huayna Picchu and built temples and terraces on its top. The peak of Huayna Picchu is about 2,720 metres (8,920 ft) above sea level, or about 360 metres (1,180 ft) higher than Machu Picchu.

According to local guides, the top of the mountain was the residence for the high priest and the local virgins. Every morning before sunrise, the high priest with a small group would walk to Machu Picchu to signal the coming of the new day. The Temple of the Moon, one of the three major temples in the Machu Picchu area, is nestled on the side of the mountain and is situated at an elevation lower than Machu Picchu. Adjacent to the Temple of the Moon is the Great Cavern, another sacred temple with fine masonry. The other major local temples in Machu Picchu are the Temple of the Condor, Temple of Three Windows, Principal Temple, "Unfinished Temple", and the Temple of the Sun, also called the Torreon

Taj Mahal

The Taj Mahal (/ˈtɑː məˈhɑːl/ often pron.: /ˈtɑːʒ/;[1] Hindi: ताज महल, from Persian/Urdu: تاج محل‎ "crown of palaces", pronounced [ˈt̪aːdʒ mɛˈɦɛl]; also "the Taj"[2]) is a white marble mausoleum located in Agra, Uttar Pradesh, India. It was built by Mughal emperor Shah Jahan in memory of his third wife, Mumtaz Mahal. The Taj Mahal is widely recognized as "the jewel of Muslim art in India and one of the universally admired masterpieces of the world's heritage".[3]

Taj Mahal is regarded by many as the finest example of Mughal architecture, a style that combines elements from Islamic, Persian, Ottoman Turkish and Indian architectural styles.[4][5]

In 1983, the Taj Mahal became a UNESCO World Heritage Site. While the white domed marble mausoleum is the most familiar component of the Taj Mahal, it is actually an integrated complex of structures. The construction began around 1632 and was completed around 1653, employing thousands of artisans and craftsmen.[6] The construction of the Taj Mahal was entrusted to a board of architects under imperial supervision, including Abd ul-Karim Ma'mur Khan, Makramat Khan, and Ustad Ahmad Lahauri.[7][8] Lahauri[9] is generally considered to be the principal designer.[10]

Dead sea

The Dead Sea (Arabic: البحر الميتAbout this sound al-Baḥr al-Mayyit,[4] Hebrew: יָם הַ‏‏מֶּ‏‏לַ‏ח, Yām HamMélaḥ, "Sea of Salt", also Hebrew: יָם הַ‏‏מָּוֶת, Yām HamMā́weṯ, "The Sea of Death"), also called the Salt Sea, is a salt lake bordering Jordan to the east and Israel and the West Bank to the west. Its surface and shores are 423 metres (1,388 ft) below sea level,[3] Earth's lowest elevation on land. The Dead Sea is 377 m (1,237 ft) deep, the deepest hypersaline lake in the world. With 33.7% salinity, it is also one of the world's saltiest bodies of water, though Lake Assal (Djibouti), Garabogazköl and some hypersaline lakes of the McMurdo Dry Valleys in Antarctica (such as Don Juan Pond) have reported higher salinities. It is 8.6 times saltier than the ocean.[5] This salinity makes for a harsh environment in which animals cannot flourish, hence its name. The Dead Sea is 55 kilometres (34 mi) long and 18 kilometres (11 mi) wide at its widest point.[1] It lies in the Jordan Rift Valley, and its main tributary is the Jordan River.

The Dead Sea has attracted visitors from around the Mediterranean basin for thousands of years. Biblically, it was a place of refuge for King David. It was one of the world's first health resorts (for Herod the Great), and it has been the supplier of a wide variety of products, from balms for Egyptian mummification to potash for fertilizers. People also use the salt and the minerals from the Dead Sea to create cosmetics and herbal sachets. In 2009, 1.2 million foreign tourists visited on the Israeli side.[citation needed]

The Dead Sea seawater has a density of 1.240 kg/L, which makes swimming similar to floating

Pyramid Giza

The Great Pyramid of Giza (also known as the Pyramid of Khufu or the Pyramid of Cheops) is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now El Giza, Egypt. It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact. Egyptologists believe that the pyramid was built as a tomb for fourth dynasty Egyptian Pharaoh Khufu (Cheops in Greek) over a 10 to 20-year period concluding around 2560 BCE. Initially at 146.5 metres (481 feet), the Great Pyramid was the tallest man-made structure in the world for over 3,800 years. Originally, the Great Pyramid was covered by casing stones that formed a smooth outer surface; what is seen today is the underlying core structure. Some of the casing stones that once covered the structure can still be seen around the base. There have been varying scientific and alternative theories about the Great Pyramid's construction techniques. Most accepted construction hypotheses are based on the idea that it was built by moving huge stones from a quarry and dragging and lifting them into place.

There are three known chambers inside the Great Pyramid. The lowest chamber is cut into the bedrock upon which the pyramid was built and was unfinished. The so-called[1] Queen's Chamber and King's Chamber are higher up within the pyramid structure. The Great Pyramid of Giza is the only pyramid in Egypt known to contain both ascending and descending passages. The main part of the Giza complex is a setting of buildings that included two mortuary temples in honor of Khufu (one close to the pyramid and one near the Nile), three smaller pyramids for Khufu's wives, an even smaller "satellite" pyramid, a raised causeway connecting the two temples, and small mastaba tombs surrounding the pyramid for nobles.