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Investigating flagellates, plankton and filter feeders
How do we enter the strange and fascinating world of small organisms? How do scientists explore their habits, growth, and rather intriguing behaviours? In this album, scientists from Italy, the US and the UK reveal some of the technologies and techniques they use to investigate the behaviour of small aquatic organisms such as flagellates, plankton and filter feeders. In the audio track, Dr David Robinson of The Open University talks about some of the problems and rewards of investigating very sm
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Investigating fungi: the wood-wide web
How fundamental are fungi to a forest's eco-system? And how can they be utilised to reclaim barren land and grow sustainable plantations for economic markets? In this album, scientists from the UK and Malaysia explore how fungi form constructive and cooperative partnerships with other plants and trees, and how such symbiosis can be used for economic and environmental benefit. In the audio track, Professor David Robinson of The Open University delves deeper into the techniques scientists use to l
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Investigating spiders: life on a thread
Whether you find spiders fearful or fascinating, they are to be admired for their web-spinning and prey-catching techniques, and the remarkable methods they use to move from one place to another. In this album, researchers in Denmark and the United States use an 8-legged robot and a virtual spider, high-speed photography, a hot air balloon and a rowing boat to explore the biophysics of spiders. In the audio track, Dr David Robinson of The Open University explains how advances in technology allow
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Bottled Water
Have you ever wondered where bottled water comes from and what impact this has on the environment? This informative, animated video looks at the complete process of producing bottled water and strives to answer the question, 'Bottled water - who needs it?' Highlighting the effects this has on the carbon footprint, we learn how bottled water is disseminated worldwide. This material forms part of the course U116 Environment: journeys through a changing world.Author(s): The iTunes U team

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Earth and Life
This series of tracks focuses on geological phenomena, Gaia theory and volcanoes. Included is a discussion on Climate Change and whether the uplift of Tibet caused global cooling. Material is taken from The Open University Course S269 Earth and Life. The iTunes U team. The iTunes U Team at The Open University produce audio and video podcasts
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Introduction

James Clerk Maxwell produced a unified theory of the electromagnetic field and used it to show that light is a type of electromagnetic wave. This prediction dates from the early 1860s when Maxwell was at King's College, London. Shortly afterwards Maxwell decided to retire to his family estate in Galloway in order to concentrate on research, unhindered by other duties. He was lured out of retirement in 1871, when he became the first professor of experimental physics in the Cavendish Laboratory
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Introduction

Energy from sources other than fossil or nuclear fuels is to a large extent free of the concerns about environmental effects and renewability that characterise those two sources. Each alternative source supplies energy continually, whether or not we use it. Many alternative sources of energy have been used in simple ways for millennia, e.g. wind and water mills, sails, wood burning - but only in the last two centuries has their potential begun to be exploited on an industrial scale. Except fo
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Introduction

Many people have the impression that underground water occupies vast caverns, such as those in the Derbyshire Peak District, flowing from one cavern to another along underground rivers. This is a common misconception: underground caverns are fairly rare, but huge quantities of water exist underground, within rocks. This is because many rocks contain pores, spaces that come in all shapes and sizes. In sediments, and consequently sedimentary rocks, there are often pores between grains which can
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Introduction

Polymers are materials composed of long molecular chains that are well-accepted for a wide variety of applications. This unit explores these materials in terms of their chemical composition, associated properties and processes of manufacture from petrochemicals. The unit also shows a range of products in which polymers are used and explains why they are chosen in preference to many conventional materials.

This OpenLearn course provides a sample of level 3 study in Author(s): The Open University

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Detecting Down’s syndrome in the unborn fetus
Downs syndrome is the condition that is screened for the most in pregnant women because of the increased risk with the increasing age of mothers. This free course, Detecting Downs syndrome in the unborn fetus, describes several bioanalytical tests, and how these are used in conjunction with scans to screen and diagnose the condition.Author(s): Creator not set

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Conclusion

  1. Eutrophication is a process in which an ecosystem accumulates mineral nutrients. It can occur naturally, but is usually associated with human activity that releases nutrients into the environment.

  2. Anthropogenic eutrophication has caused a widespread loss of biodiversity in many systems. Recent attempts to reverse the process are proving difficult and expensive.

  3. Symptoms of eutrophication are most readily seen in aquatic sys
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3.2.5 Sediments

Sediments have a variable but complex role in nutrient cycling in most aquatic systems, and are a potential 'internal' source of pollutants. Release of phosphorus from lake sediment is a complex function of physical, biological and chemical processes and is not easy to predict for different systems. Nitrogen is not stored and released from sediments in the same way, so its turnover time within aquatic systems is quite rapid. Nitrogen concentrations tend to fall off relatively quickly followin
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2.4.2 Saltmarshes

Marsh plant primary production is generally nitrogen limited, so saltmarsh vegetation responds readily to the artificial eutrophication that is now so common in nearshore waters. Eutrophication causes marked changes in plant communities in saltmarshes, just as it does in freshwater aquatic and terrestrial systems. Biomass production increases markedly as levels of eutrophication increase. Increases in the nitrogen content of plants cause dramatic changes in populations of marsh plant consumer
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1.2 Resource availability and species diversity

A wide range of ecosystems has been studied in terms of their species diversity and the availability of resources. Each produces an individual relationship between these two variables, but a common pattern emerges from most of them, especially when plant diversity is being considered. This pattern has been named the humped-back relationship and suggests diversity is greatest at intermediate levels of productivity in many systems (Figure 1.5).

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6.2 Non-covalent bonding in site-specific binding

The affinity of a protein for DNA is determined in thermodynamic terms by the free energies of the individual components compared to the free energy of the DNA-protein complex. DNA binding proteins, which contain different binding motifs, demonstrate a wide range of thermodynamic strategies.

The affinity of a site-specific DNA binding protein for its specific DNA sequence is generally of the order of 104−107 times greater than its affinity for non-specific sequen
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5.1 Introduction

The integrity of DNA as a genetic material is of paramount importance to an organism, and a multitude of proteins exist that serve to prevent or reverse damage to the DNA. However, like all biological macromolecules, DNA decomposes spontaneously. The reasons for the ease of decomposition of DNA are intimately linked to the chemical structures of the constituent bases and phosphodiester-linked sugars. The limited stability of DNA may be integral to the molecular basis of evolution. If DNA were
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4.1 The varied structures of RNA

RNA is a versatile cellular molecule with the ability to adopt a number of complex structural conformations. Although RNA is often thought of as a single-stranded molecule it is actually highly structured.

SAQ 19

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Torsional energy can be taken up by alternative DNA conformations

The energy introduced into DNA by twisting has great potential as a regulatory mechanism, since the free energy can be stored in a variety of different high-energy conformations along the chain.

SAQ 14

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Base stacking

Although the base pairing brought about by hydrogen bonding is responsible for the specificity of the base interactions, much of the stability of a duplex nucleic acid is due to interactions that result from base stacking. If you look back at Figure 3a, you will notice that, when seen from a side view, our schematic r
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Acknowledgements

Except for third party materials and otherwise stated (see terms and conditions). This content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence

Grateful acknowledgement is made to the following sources for permission to reproduce materia
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