U.S. Morning Call: Obama, governors weigh budget proposals
Dec 4 - With just a few weeks remaining before the onset of tax hikes and spending cuts, a bipartisan delegation of governors is set to meet with President Obama to go over solutions.
Author(s): No creator set

License information
Related content

Donna Britt: 2012 National Book Festival
Donna Britt appears at the 2012 Library of Congress National Book Festival. Speaker Biography: Washington Post columnist Donna Britt has spent her life surrounded by men -- her three brothers, two husbands and three sons. When her brother Darrell was killed by police 30 years ago, Britt unconsciously sought to help other men the way she couldn't help Darrell. Her new book, "Brothers (& Me): A Memoir of Loving and Giving," navigates Britt's life through her relationships with men, resulting in a
Author(s): No creator set

License information
Related content

2.854 Manufacturing Systems I (SMA 6304) (MIT)
As the first in a sequence of four half-term courses, this course will provide the fundamental building blocks for conceptualizing, understanding and optimizing manufacturing systems and supply chains. These building blocks include process analysis, queuing theory, simulation, forecasting, inventory theory and linear programming. This course was also taught as part of the Singapore-MIT Alliance (SMA) programme as course number SMA 6304 (Manufacturing Systems I: Analytical Methods and Flow Models
Author(s): Gershwin, Stanley

License information
Related content

Content within individual OCW courses is (c) by the individual authors unless otherwise noted. MIT OpenCourseWare materials are licensed by the Massachusetts Institute of Technology under a Creative C

Resource #10138
UNSPECIFIED - UNSPECIFIED Keywords:UNSPECIFIED
Author(s): No creator set

License information
Related content

Integrative Biology 131 - Lecture 02: Skeletal System

General Human Anatomy. UC Berkeley lecture with Professor Marian Diamond. The functional anatomy of the human body as revealed by gross and microscopic examination.

read more


Author(s): EduTube

License information
Related content

Rights not set

Student Affairs State of the Division
On September 25, 2012, the Division of Student Affairs at the University of California Berkeley held its first State of the Division event. This event was hosted by the Vice Chancellor who provided an overview of the state of affairs of the division. It included presentations by the Director of HR and Budget, Executive Director Student Service Systems, and Director of the Career Center, who discussed the strategic budget planning process, student systems technology, and the opening of the new C
Author(s): No creator set

License information
Related content

4.4 Reducing nutrient availability

Once nutrients are in an ecosystem, it is usually much harder and more expensive to remove them than tackle the eutrophication at source. The main methods available are:

  • precipitation (e.g. treatment with a solution of aluminium or ferrous salt to precipitate phosphates);

  • removal of nutrient-enriched sediments, for example by mud pumping; and

  • removal of biomass (e.g. harvesting of common reed) and using it for thatchi
    Author(s): The Open University

    License information
    Related content

    Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

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 2.0 Licence

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

Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

7.7 Physical hazards

In any laboratory, potential hazards arise from the use of electrical equipment. The legal requirements relating to the use and maintenance of such equipment are contained in the ‘Electricity at Work Regulations 1989’ (EAW). The regulations require certain safety objectives to be achieved but do not prescribe in detail the measures to be taken. Instead, precautions should be selected appropriate to risk depending on particular work activities.

‘Portable’ electrical equipment –
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

5.2 Cryogenic liquids and ionising radiation safety

5.2.1 Cryogenic liquids

There are a number of hazards associated with cryogenic liquids, the main one being that when accidentally released the liquid expands hugely to form a gas (600 times in the case of nitrogen). The formation of such a large volume of gas can lead to asphyxiation in confined areas.

The other main hazard is cold burns (frostbite).

    Author(s): The Open University

    License information
    Related content

    Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

4.1 Vitamin A deficiency

Vitamin A, more properly known as retinol, is an important chemical intermediate in a number of biochemical processes in mammals. It is involved in vision, and is found in the rod cells of the retina of the eye. These cells are particularly important in seeing at low light levels, and night blindness is a symptom of vitamin A deficiency (VAD). Vitamin A is also involved in the proper functioning of the immune system. Children suffering from VAD are prone to serious infections, and often die f
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

Learning outcomes

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

  • understand more about the science that underlies the development of genetically modified organisms and in particular how gene transfer is brought about;

  • know something of the potential benefits and uncertainties associated with gene transfer and the high levels of technical ingenuity involved;

  • be better able to understand the science that underpins the development of Golden Rice and understand why the u
    Author(s): The Open University

    License information
    Related content

    Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

1 How do organisms acquire iron?

Metals are an essential part of biological chemistry. Of all the trace elements, iron is the most important, especially as it is present in many essential enzymes and proteins. But how do organisms acquire the iron from their surroundings? Clearly, organisms need to absorb iron biochemically before it can be used in proteins. Also, some method of replacing lost iron quickly is needed: for instance, how is blood replaced once it has been lost through a cut? This prompts the question: what bioc
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

Introduction

In this unit we will see that, despite having a high natural abundance, iron is in very short supply because of the insolubility of its oxides and hydroxides. A result of this is that organisms have developed methods for the uptake, transport and storage of iron. For example, iron storage in mammals, including humans, is achieved by ferritin, which stores iron as a hydrated iron(III) oxide – an example of biomineralisation.

This unit is from our archive and is an adapted extract from
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

1.3 Protein secondary structure

From our consideration of the steric constraints that apply to peptide bonds and amino acid residues in a polypeptide, we have already begun to discuss some of the factors that determine how the backbone of the polypeptide folds. The conformation adopted by the polypeptide backbone of a protein is referred to as secondary structure. Whilst it is true to say that all proteins have a unique three-dimensional structure or conformation, specified by the nature and sequence of their amino a
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

1.1 So what's it all about?

iSpot is a website aimed at helping anyone identify anything in nature. Once you've registered, you can add an observation to the website and suggest an identification yourself or see if anyone else can identify it for you. You can also help others by adding an identification to an existing observation, which you may like to do as your knowledge grows. Your reputation on the site will grow as people agree with you identifications. You may also like to visit our forums which offer lively debat
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

1.6.4 Drop-towers revisited

In Section 1 we described how research into near weightless conditions can be carried out on Earth by using a drop-tower or a drop-shaft (Figure 41). We are now in a position to examine drop-shafts in more detail (Example 3).

Figure 41
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

1.5.5 Derived functions and derivative notation

Given the function x(t) that describes some particular motion, you could plot the corresponding position–time graph, measure its gradient at a variety of times to find the instantaneous velocity at those times and then plot the velocity–time graph. If you had some time left, you might go on to measure the gradient of the velocity–time graph at various times, and then plot the acceleration–time graph for the motion. This would effectively complete the description of the m
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

1.5.4 Functions and the function notation

In Figure 25, the position x of the car depends on the time t. The graph associates a particular value of x with each value of t over the plotted range. In other circumstances we might know an equation that associates a value of x with each value of t, as in the case of the equation x = At + B that we discussed in Section 3. You can invent countless other ways in which x depends on t: for instance x = 
Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

1.5.3 A note on functions and derivatives

This subsection introduces two crucially important mathematical ideas, functions and derivatives, both of which are used throughout physics.


Author(s): The Open University

License information
Related content

Except for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share