Q (or Query) fever is a disease that is caused by the bacterium Coxiella burnetii. The bacterium is passed to humans by contact with infected animals such as sheep, cattle, and goats, which are the main reservoirs of the microorganism. The...

QĀḌĪ. A qāḍī is a judge responsible for the application of Islamic positive law (fiqh). The office originated under the rule of the first Umayyad caliphs (AH 40–85/661–705 CE), when t...

The Qajar dynasty in Persia (present-day Iran) spanned 130 years, beginning with Agha Mohammad Qajar in 1795 and ending with Ahmad Shah in 1925. It was a period in Persian history that saw substantial British and Russian regional influence...

(1998 est. pop. 190,000). Karshi, in the southern part of the republic of Uzbekistan in Central Asia, is an ancient city on the old trade route between Afghanistan and Samarqand. Situated in a fertile oasis of the Kashka Darya River, today...

QI is one of the most complex and multifaceted terms in all of Chinese philosophy, religion, and science. No single word can translate it adequately. Its root meaning is "moist emanation." Steam, clouds, and mist are qi, and ...

Qigong refers to Chinese mental and physical exercises that cultivate qi (ch'i). Daoist in origin and often associated with healing, longevity, and enlightenment, these practices increase suppleness, develop relaxation, and improve ...

In 221 BCE, the King of Qin concluded the invasion of the Warring States and established the Qin Empire, declaring himself the "First August Emperor of Qin." Having conquered Qi, Chu, Yan, Han, Zhao and Wei, the Qin Emperor envisioned a dyn...

(2002 pop. 5.3 million). A remote province in western China, Qinghai (Blue Sea) has a population that includes Han Chinese and Tibetans, as well as Mongols and Kazakh, Hui, Salar, and Tu minorities. The capital Xining (Western Peace) has a...

Qingming is the second-most-important seasonal festival, after the Lunar New Year, involving ancestral veneration in China. The term literally means clear and transparent, or brightness, implying the arrival of spring, after the dark and c...

(1875–1907), Chinese revolutionary and advocate of women's rights. Qiu Jin (Ch'iu Chin) was born into a well-to-do family in China's Shaoxing, Zhejiang Province. She received a good education, but at the age of ...

(2001 pop. 873,000). Approximately 130 kilometers south of Tehran, Qom is situated in a semiarid interior basin of central Iran along the Qom River, which flows down from the Zagros Mountains, through Qom, and into the large Darya-e Namak ...

A quadratic equation is an equation of the second degree, meaning that for an equation in x, the greatest exponent on x is 2. Quadratics most commonly refer to vertically oriented parabolas—that is, parabolas that open upward or dow...

Quadriplegia A complete paralysis of the arms, legs, and trunk, usually occurring after a severe injury to the spinal cord between the fifth and seventh vertebrae. Spastic quadriplegia is a condition present at birth often accompanied by v...

Qualia The word quale (or qualia ) derives from the Latin for "quality." As used by C. I. Lewis (1929) and those following him, it refers to the qualities of phenomenal individuals, such as color patches, tastes, and sounds. ...

Qualitative analysis involves determining the composition of an unknown compound or mixture. Qualitative analysis can also analyze a mixture to determine the precise percentage composition of the sample in terms of elements, radicals, and ...

Quality management (QM), also called total quality management (TQM), evolved from many different management practices and improvement processes. Quality management is not specific to managing people, but rather is related to improving the ...

The Quan Tangshi (Complete Tang Poems) is the most complete collection of Tang dynasty (618–907 CE) and Five Dynasties (907–960 CE) verse. It consists of 900 fascicles, with 48,900 works by more than 2,200 writers. The compil...

Quantitative analysis involves measuring the proportions of known components in a mixture. Whereas qualitative analysis involves identifying what materials are present in a sample (quality), quantitative analysis involves determining how m...

Quantitative traits are those that vary continuously. This is in contrast to qualitative traits, in which the phenotype is discrete and can take on one of only a few different values. Examples of quantitative traits include height, weight,...

Quantum chemistry involves the application of the principles of quantum theory to chemistry. Quantum chemistry helps predict the way atoms combine to form molecules, and the way molecules interact with each other. Applications of quantum c...

Quantum computing refers to the current theoretical use of quantum physics in the processing and memory functions of computing. Certain properties of atoms or nuclei could allow the processing and memory functions to cooperatively function...

Quantum electrodynamics (QED) is a scientific theory that is also known as the quantum theory of light. QED describes the quantum properties (properties that are conserved and that occur in discrete amounts called quanta) and mechanics as...

Relativity and quantum theory, the foundations upon which all of modern physics rests, were developed in the first quarter of the twentieth century. Their accuracy in predicting the results of experiment or observation is astounding; the s...

LIGHT In the everyday sense of the word, it seems like a simple thing: but it is a subject for serious consideration. I am exploring here the role of light in relativity, not its nature. Light has always been a benchmark of the highest spe...

A quantum state is the condition a quantum mechanical system is in. The state is usually described by a wave function. It is different from classical states of systems in that the quantum system has separate, discrete levels, whereas the s...