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Trading at Noon: Red envelope to battle Redbox
Dec 12 - Verizon and Coinstar are set to launch a streaming service, 'Redbox Instant' to take on video rental giant Netflix.
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Artists at Google: Mayday 五月天
Talks at Google welcomed Mayday to Google headquarter in Mountain View, California for an exclusive talk to discuss their work and how they're reaching fans across borders. Google+ Global Marketing Director Marvin Chow interviewed Mayday on November 28th, 2012. Mayday also held a concert, live streamed around the world, later that night for YouTube Presents. Watch their exciting performance here: http://www.youtube.com/watch?v=ZUXVS4ILYBY Mayday An influential rock band from Taiwan. With footp
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Long Live the Loophole

Editor's Note: Although negotiations concerning the "fiscal cliff" seem to be at an impasse, the one thing both Democrats and Republicans agree on is their desire to close tax loopholes. That is bad news for the economy, because as Ludwig von Mises said, "Capitalism breathes through those loopholes." Closing loopholes to "broaden the tax base" has been a supply
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The loss of a DNA base causes an abasic site

Hydrolysis of the deoxyribose Cl'–base linkage results in the complete loss of a purine or pyrimidine base, resulting in what is called an abasic site, an event with obvious genetic consequences. This hydrolysis reaction is much more likely to occur at purine bases, resulting in depurination of the DNA (Table 3a<
Author(s): The Open University

2.5 Obesity and brain reward systems

Very palatable foods, especially those high in fat and carbohydrate may be potent stimuli for neural pathways in the brain. Direct evidence for this idea has been found in recent studies of non-human animals. For example, it is known that many types of both natural (i.e. food, sex) and drug (e.g. cocaine or amphetamine, opiates, nicotine) rewards are able to stimulate activity within a brain pathway that innervates the ventral striatum at the base of the forebrain (Author(s): The Open University

2.3 Broadband spectra

The broadband spectrum is the spectrum over all the observed wavelength ranges. To plot the broadband spectrum of any object it is necessary to choose logarithmic axes.

  • Why is it necessary to use logarithmic axes?

  • Because both the spectral flux density, Fλ, and the wavelength vary by many powers of 10.

Author(s): The Open University

Introduction

Active galaxies provide a prime example of high-energy processes operating in the Universe. This unit introduces the evidence for activity from the spectra of some galaxies, and the concept of a compact active galactic nucleus as a unifying model for the observed features of several types of active galaxy. It also develops the key skill of applying arithmetic and simple algebra to solving scientific problems.

This course is an adapted extract fromt he course Author(s): The Open University

Acknowledgements

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Readings

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Other third party material is acknowledged as it appears within the content of the unit.

Reading 1: Miller, S. (2001) ‘Publ
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3.1 Introduction

On an autumnal morning in November 1994, a group of people gathered at Regent's College, London, conscious that they were making history. The purpose of the meeting was to discuss an important issue: plant biotechnology and how it should be regulated in the UK. At the time, the genetic engineering of plants was emerging as a technology of great potential for the development of new pest-resistant, higher yield crops, although the technique hadn't attracted the degree of media attention and pub
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Acknowledgements

The content acknowledged below is Proprietary (see terms and conditions) and is used under licence. This content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence

Grateful acknowledgement is made to the following sources for permission to reproduce material in this unit:


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3.6.2 Experiencing the pregnancy

If a woman does find herself pregnant, what can she expect? Pregnancy is a time of enormous physical and emotional changes, and these are often difficult to cope with. To begin with, the physical effects of early pregnancy can be extremely unpleasant. The nausea and vomiting of morning sickness can be very severe, and although in many women the symptoms abate after a while, in others they persist right through the pregnancy. Sickness is thought to be due to the high levels of progestogen circ
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3.1 Introduction

The simplest and oldest way of storing surface water is in reservoirs and this has been done for thousands of years. Most reservoirs are still built to increase water supplies, but some are also built for other purposes, especially for generating hydroelectric power and for protection against floods. The Tennessee River in the United States, for example, has reservoirs to trap and store water that would otherwise cause floods, the water being released when the height of the river falls to saf
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6 Direct heating using geothermal energy

In the same way that waste heat from conventional power stations can be used for direct heating of buildings, and in industrial production and horticulture, low-grade geothermal energy has considerable potential. Many existing developments, such as those in Iceland, use spent fluids from geothermal electricity generation. Areas of natural hot springs are an obvious target, but it is also relatively simple to exploit normal heat flow using either natural groundwater or a variety of heat-exchan
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4 Locating high-enthalpy geothermal fields

The search for potentially useful geothermal fields focuses initially on locating rocks that have been chemically altered by natural geothermal fluids, as well as looking for obvious surface features of geothermal activity such as geysers and hot springs. Measurements of fluid flow through the field allow estimation of its likely economic potential.

When a promising resource has been located exploration wells are drilled. However, given the high pressures and temperatures typical of a g
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2.7 Summary

  1. Eukaryotic cells contain numerous distinct types of membrane-bound compartment. Transport vesicles move proteins and other molecules between the compartments.

  2. Proteins contain signalling sequences or patches that specify their destination compartment.

  3. Proteins destined for lysosomes, secretion or the plasma membrane are synthesised in the ER, transported to the cis Golgi, modified in the Golgi apparatus, and sorted and pa
    Author(s): The Open University

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3.6.2 The JAK–STAT pathway

Another important protein kinase pathway is the JAK–STAT pathway. Cytokines (Section 2.2), are frequently used for signalling between cells of the immune system. Cytokine-induced signal transduction cascades are often direct pathways to the nucleus for switching on sets of genes. Janus kinases (JAKs, named after the two-faced Roman god) are a particular
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3.6.1 The MAP kinase pathway

The MAP kinase pathway is so called because the last component of the pathway was originally identified as a kinase activity in EGF-stimulated cells – hence the name ‘mitogen-activated protein kinase’ (MAP kinase), as it stimulates cell growth and proliferation.

  • What is the mechanism of activation of the EGF receptor?

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1.7 Localization of signalling proteins

Since signalling proteins cannot diffuse as rapidly as small second messengers, they need be close to their downstream target in order to be able to function. Where they are located with respect to both their subcellular position and their immediate neighbours is therefore vitally important. The plasma membrane is usually the initial location, and proteins can be attached to the plasma membrane in various ways (Author(s): The Open University

6.2 Catalytic mechanisms

In general terms, the following mechanisms operate at the active site of an enzyme to bring about the conversion of substrate to product:

  1. Charged groups at the enzyme active site alter the distribution of electrons in the substrate. By affecting the electron distributions in key atoms in the substrate, the enzyme can destabilise existing bonds and favour the formation of new bonds. This principle is illustrated below, using as an example the hydrolysis
    Author(s): The Open University

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