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1.3 Minerals and rocks

To begin with, it is necessary to explain the meanings of the two terms ‘minerals’ and ‘rocks’.


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1.1 About this unit

Science is all about knowledge, what we know about the material world and the Universe in which our world is just a microscopic speck. The aim of scientists is to extend the frontiers of this knowledge so that we can understand more about the physical Universe and the life within it.

Scientists acquire knowledge by engaging in four fundamentally important and connected tasks. The first is observation: they observe the natural world and the space beyond it, and both describe and r
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Learning outcomes

By the end of this unit you should be able to:

  • explain the difference between a mineral and a rock;

  • describe the textural differences between igneous, sedimentary and metamorphic rocks;

  • account for these differences in terms of the processes that produce these rocks;

  • classify igneous rocks according to their grain size and mineralogical composition;

  • recognise the difference between a body fossil and a trace fossil;

    <
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References

N. Carlson (2007) ‘Physiology of Behaviour’ 9th International Edition. Boston: Allyn and Bacon.

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8 Websites for further information:

Primers on drug addiction:

For general in
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5.3.2 Conclusion after reading this article:

The paper suggests that the factors that had long been considered responsible for neurodegenerative disease are also important for normal neuronal function. For example, they exert a physiological homeostatic effect by reducing excitatory transmission in Author(s): The Open University

5.2 Neural ageing: article 2

In the article presented here by Esteban (2004) entitled ‘Living with the enemy: a physiological role for theβ-amyloid peptide’, Trends in Neurosciences, 27, pp. 1–3, the author introduces us to a very important molecule implicated in the aetiology of Alzheimer's disease. However, the β-am
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5.2.2 Calorie restriction

Since the publication of Osborne, Mendel and Ferry's paper (Science, 1917, Vol 45, pp. 294–5) calorie restriction has been the most reliable method of extending the lifespan of laboratory animals. These results have been confirmed by many researchers and have been extended to a variety of verteb
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5.2 Neural ageing: article 1

Now read Neural Ageing Article 1: Concar, D. (2001) ‘Forever young’, New Scientist, 171, pp. 26–27.

Click to view 'Concar article'

4.7 Ageing brains: hope for the future

Due to the enormous progress in the field of molecular and cell biology, new avenues in brain research have opened up.
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4.6 Consequences of neural ageing

While we are beginning to understand the underlying molecular and cellular changes that take place in the ageing brain, the consequences of these changes are all too familiar. As people age, their mental competence may change and their ability to cope with the demands of everyday life may alter. A decline in
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4.2 Definitions of ageing

The term ‘ageing’ carries a number of different meanings. It encompasses changes that occur at many levels, from the population down to the molecular. Even at a single level, ageing does not represent a single process, but many processes, which may operate independently. Therefore, the challenge of defining ageing is more complex than it might first
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3.1.2. After reading this article:

The chapter by Teesson et al. (2002) will have presented you with a clearly written initial orientation to addiction. The article introduced addiction at several different levels of explanation in what the authors term a ‘biopsy chosocial model’ (p. 47). Such an integrated model is at the heart of the app
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3.1 Addiction article 1

The first selected reading provides a wide ranging review of the theories associated with addiction illustrating how the subject can be investigated at a number of different levels of analysis. The second article explores one particular level further, the pharmacology of drug addiction, and asks why specific drugs are more likely to induce addictive behaviour.


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2.2 Specific issues in addiction

  1. The term ‘addiction’ carries a number of different meanings. The word is generally used with reference to drugs (e.g. heroin, nicotine, alcohol), where a person is described as being ‘dependent on’ or ‘addicted to’ a substance. Also, substances are described as ‘addictive’ or ‘non-addictive’, implying that addiction is an intrinsic property of the substance. Some people are addicted to food. Given that food is necessary, in what sense is
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2.1 Introduction

Professor Trevor Robbins of Cambridge University, an expert in cognitive neuroscience, commented that:

Our understanding of the nature of drug addiction over the last few decades has depended on several important theoretical insi
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2.1.2 Diffraction and interference of light

When light, or indeed any type of wave, passes through a narrow aperture, it will spread out on the other side. This is the phenomenon of diffraction. For example Figure 17 shows the diffraction of water waves in a device called a ripple tank. The extent to which waves are diffracted depends on the size of the aperture rel
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1.5.5 Point spread function and angular resolution

The image of a point-like source of light (such as a distant star) obtained using a telescope will never be a purely point-like image. Even in the absence of aberrations and atmospheric turbulence to distort the image, the image of a point-like object will be extended due to diffraction of light by the telescope aperture. The bigger the aperture, the smaller is the effect, but it is still present nonetheless. The intensity of the image of a point-like object will take the form shown in
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