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| == '''[[NMR spectroscopy]]''' ==
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| '''NMR spectroscopy''' (MR spectroscopy, NMR or Nuclear Magnetic Resonance Spectroscopy) measures the energy differences between the spin states of nuclei in the presence of a magnetic field by using radio frequency electromagnetic radiation.<ref> I. I. Rabi.(1937) Phys. Rev., 51 652</ref><ref>N. Bloembergen, E. Purcell and R.V.Pound. (1948). Phys. Rev. 73, 679.</ref> <ref>F. Bloch, W. Hansen, and M.E. Packard, (1946) Phys. Rev. 69, 127.</ref> The energy differences between the spin states of the nuclei depend upon the nature of the atom and are influenced by its environment. However, NMR spectroscopy is not limited to measurement of the energy differences between the spin states. NMR signals are also influenced by the motion of the nucleus and the rotational motion of the molecule within which the observed nucleus resides. Therefore, NMR spectroscopy provides static (structure and composition) as well as dynamic information regarding the system of interest, e.g., [[protein]]s, [[DNA]] and other natural products.
| | ==Footnotes== |
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| Pulses of radio-frequency electromagnetic radiation can be used to perturb the nuclear spin systems in a variety of ways; the time dependent response of the system of interest can be recorded and analyzed:
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| * to correlate different spectral properties of nuclei and/or
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| * to extract information regarding interactions between nuclear spins within the same molecule and/or
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| * to obtain information regarding intermolecular interactions.
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| The amplitude, frequency, phase and duration of pulses of radio-frequency electromagnetic radiation, as well as static and dynamic position dependent magnetic fields, can be varied in many combinations giving rise to a wide variety of NMR spectroscopic experiments.
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| NMR spectroscopic techniques are used extensively for structural elucidation of natural products and for quantitative analysis of components of complex mixtures such as body fluids. However, its applications are not limited to these systems; and
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| NMR spectroscopy has been used for the study of matter in disordered, ordered and partially ordered systems such as gases, liquids, [[quantum fluids]]
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| <ref>D.D.Osheroff, W.J.Gully, R.C.Richardson and D.M.Lee, Phys. Rev. Lett. (1972) 29, 920 </ref> <ref>http://nobelprize.org/nobel_prizes/physics/laureates/1996/lee-lecture.pdf </ref>, | |
| superconductors, solutions, amorphous solids, crystalline solids, [[liquid crystals]], membranes and living organisms. NMR spectroscopic methods have also found use in [[quantum computing]].
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| ''[[NMR spectroscopy|.... (read more)]]''
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| ! style="text-align: center;" | [[NMR spectroscopy#References|notes]]
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The Mathare Valley slum near Nairobi, Kenya, in 2009.
Poverty is deprivation based on lack of material resources. The concept is value-based and political. Hence its definition, causes and remedies (and the possibility of remedies) are highly contentious.[1] The word poverty may also be used figuratively to indicate a lack, instead of material goods or money, of any kind of quality, as in a poverty of imagination.
Definitions
Primary and secondary poverty
The use of the terms primary and secondary poverty dates back to Seebohm Rowntree, who conducted the second British survey to calculate the extent of poverty. This was carried out in York and was published in 1899. He defined primary poverty as having insufficient income to “obtain the minimum necessaries for the maintenance of merely physical efficiency”. In secondary poverty, the income “would be sufficient for the maintenance of merely physical efficiency were it not that some portion of it is absorbed by some other expenditure.” Even with these rigorous criteria he found that 9.9% of the population was in primary poverty and a further 17.9% in secondary.[2]
Absolute and comparative poverty
More recent definitions tend to use the terms absolute and comparative poverty. Absolute is in line with Rowntree's primary poverty, but comparative poverty is usually expressed in terms of ability to play a part in the society in which a person lives. Comparative poverty will thus vary from one country to another.[3] The difficulty of definition is illustrated by the fact that a recession can actually reduce "poverty".
Causes of poverty
The causes of poverty most often considered are:
- Character defects
- An established “culture of poverty”, with low expectations handed down from one generation to another
- Unemployment
- Irregular employment, and/or low pay
- Position in the life cycle (see below) and household size
- Disability
- Structural inequality, both within countries and between countries. (R H Tawney: “What thoughtful rich people call the problem of poverty, thoughtful poor people call with equal justice a problem of riches”)[4]
As noted above, most of these, or the extent to which they can be, or should be changed, are matters of heated controversy.
- ↑ Alcock, P. Understanding poverty. Macmillan. 1997. ch 1.
- ↑ Harris, B. The origins of the British welfare state. Palgrave Macmillan. 2004. Also, Oxford Dictionary of National Biography.
- ↑ Alcock, Pt II
- ↑ Alcock, Preface to 1st edition and pt III.
