Genetic engineering

Genetic engineering, also called genetic modification, is the direct human manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest. The introduction of new DNA does not require the use of classicalgenetic methods, however traditional breeding methods are typically used for the propagation of recombinant organisms.

An organism that is generated through the introduction of recombinant DNA is considered to be a genetically modified organism. The first organisms genetically engineered were bacteria in 1973 and then mice in 1974. Insulin-producing bacteria were commercialized in 1982 and genetically modified food has been sold since 1994.

The most common form of genetic engineering involves the insertion of new genetic material at an unspecified location in the host genome. This is accomplished by isolating and copying the genetic material of interest using molecular cloning methods to generate a DNA sequence containing the required genetic elements for expression, and then inserting this construct into the host organism. Other forms of genetic engineering include gene targeting and knocking out specific genes via engineered nucleases such as zinc finger nucleases or engineered homing endonucleases.

Genetic engineering techniques have been applied in numerous fields including research, biotechnology, and medicine. Medicines such as insulin and human growth hormone are now produced in bacteria, experimental mice such as the oncomouse and the knockout mouse are being used for research purposes and insect resistant and/or herbicide tolerant crops have been commercialized. Genetically engineered plants and animals capable of producing biotechnology drugs more cheaply than current methods (called pharming) are also being developed and in 2009 the FDA approved the sale of the pharmaceutical protein antithrombin produced in the milk of genetically engineered goats.

Genetic engineering alters the genetic makeup of an organism using techniques that introduce heritable material prepared outside the organism either directly into the host or into a cell that is then fused or hybridized with the host.^[1] This involves using recombinant nucleic acid (DNA or RNA) techniques to form new combinations of heritable genetic material followed by the incorporation of that material either indirectly through a vector system or directly through micro-injection, macro-injection and micro-encapsulation techniques. Genetic engineering does not include traditional animal and plant breeding, in vitro fertilisation, induction of polyploidy, mutagenesis and cell fusion techniques that do not use recombinant nucleic acids or a genetically modified organism in the process.^[1] Cloning and stem cell research, although not considered genetic engineering,^[2] are closely related and genetic engineering can be used within them.^[3] Synthetic biology is an emerging discipline that takes genetic engineering a step further by introducing artificially synthesized genetic material from raw materials into an organism.^[4]

If genetic material from another species is added to the host, the resulting organism is called transgenic. If genetic material from the same species or a species that can naturally breed with the host is used the resulting organism is called cisgenic.^[5] Genetic engineering can also be used to remove genetic material from the target organism, creating a gene knockout organism.^[6] In Europe genetic modification is synonymous with genetic engineering while within the United States of America it can also refer to conventional breeding methods.^[7] Within the scientific community, the term genetic engineering is not commonly used; more specific terms such as transgenic are preferred.

Biotechnology

Biotechnology (sometimes shortened to "biotech") is a field of applied biology that involves the use of living organisms and bioprocesses in engineering, technology, medicine, and other fields requiring bioproducts. Biotechnology also utilizes these products for manufacturing purposes. Modern use of similar terms includes genetic engineering as well as cell and tissue culture technologies. The concept encompasses a wide range of procedures (and history) for modifying living organisms according to human purposes — going back to domestication of animals, cultivation of plants, and "improvements" to these through breeding programs that employ artificial selection and hybridization. By comparison to biotechnology, bioengineering is generally thought of as a related field with its emphasis more on higher systems approaches (not necessarily altering or using biological materials directly) for interfacing with and utilizing living things. The United Nations Convention on Biological Diversity defines biotechnology as:^[1]

"Any technological application that uses biological systems, living organisms, or derivatives thereof, to make or modify products or processes for specific use."

In other terms: "Application of scientific and technical advances in life science to develop commercial products" is biotechnology. Biotechnology draws on the pure biological sciences (genetics, microbiology, animal cell culture, molecular biology, biochemistry, embryology, cell biology) and in many instances it is also dependent on knowledge and methods from outside the sphere of biology (chemical engineering, bioprocess engineering, information technology, biorobotics). Conversely, modern biological sciences (including even concepts such as molecular ecology) are intimately entwined and dependent on the methods developed through biotechnology and what is commonly thought of as the life sciences industry.

An Illustrated History of Computers

The first computers were people! That is, electronic computers (and the earlier mechanical computers) were given this name because they performed the work that had previously been assigned to people. "Computer" was originally a job title: it was used to describe those human beings (predominantly women) whose job it was to perform the repetitive calculations required to compute such things as navigational tables, tide charts, and planetary positions for astronomical almanacs. Imagine you had a job where hour after hour, day after day, you were to do nothing but compute multiplications. Boredom would quickly set in, leading to carelessness, leading to mistakes. And even on your best days you wouldn't be producing answers very fast. Therefore, inventors have been searching for hundreds of years for a way to mechanize (that is, find a mechanism that can perform) this task.

The abacus was an early aid for mathematical computations. Its only value is that it aids the memory of the human performing the calculation. A skilled abacus operator can work on addition and subtraction problems at the speed of a person equipped with a hand calculator (multiplication and division are slower). The abacus is often wrongly attributed to China. In fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians. The abacus is still in use today, principally in the far east. A modern abacus consists of rings that slide over rods, but the older one pictured below dates from the time when pebbles were used for counting (the word "calculus" comes from the Latin word for pebble).

In 1617 an eccentric (some say mad) Scotsman named John Napier invented logarithms, which are a technology that allows multiplication to be performed via addition. The magic ingredient is the logarithm of each operand, which was originally obtained from a printed table. But Napier also invented an alternative to tables, where the logarithm values were carved on ivory sticks which are now called Napier's Bones.

The Concept of the Ecosystem

I bequeathe myself to the dirt, to grow from the grass I love;

If you want me again, look for me under your boot-soles."

- Walt Whitman

In this lesson, we will learn answers to the following questions:

    What is an ecosystem, and how can we study one?

    Is the earth an open or closed system with respect to energy and elements?

    How do we define "biogeochemical cycles," and how are they important to ecosystems?

    What are the major controls on ecosystem function?

    What are the major factors responsible for the differences between ecosystems?

Introduction - What is an Ecosystem?

An ecosystem consists of the biological community that occurs in some locale, and the physical and chemical factors that make up its non-living or abiotic environment. There are many examples of ecosystems -- a pond, a forest, an estuary, a grassland. The boundaries are not fixed in any objective way, although sometimes they seem obvious, as with the shoreline of a small pond. Usually the boundaries of an ecosystem are chosen for practical reasons having to do with the goals of the particular study.

The study of ecosystems mainly consists of the study of certain processes that link the living, or biotic, components to the non-living, or abiotic, components. Energy transformations and biogeochemical cycling are the main processes that comprise the field of ecosystem ecology. As we learned earlier, ecology generally is defined as the interactions of organisms with one another and with the environment in which they occur. We can study ecology at the level of the individual, the population, the community, and the ecosystem.

Studies of individuals are concerned mostly about physiology, reproduction, development or behavior, and studies of populations usually focus on the habitat and resource needs of individual species, their group behaviors, population growth, and what limits their abundance or causes extinction. Studies of communities examine how populations of many species interact with one another, such as predators and their prey, or competitors that share common needs or resources.

In ecosystem ecology we put all of this together and, insofar as we can, we try to understand how the system operates as a whole. This means that, rather than worrying mainly about particular species, we try to focus on major functional aspects of the system. These functional aspects include such things as the amount of energy that is produced by photosynthesis, how energy or materials flow along the many steps in a food chain, or what controls the rate of decomposition of materials or the rate at which nutrients are recycled in the system.

  Components of an Ecosystem

You are already familiar with the parts of an ecosystem. You have learned about climate and soils from past lectures. From this course and from general knowledge, you have a basic understanding of the diversity of plants and animals, and how plants and animals and microbes obtain water, nutrients, and food. We can clarify the parts of an ecosystem by listing them under the headings "abiotic" and "biotic".

  

ABIOTIC COMPONENTS

               

BIOTIC COMPONENTS

Sunlight                Primary producers

Temperature     Herbivores

Precipitation      Carnivores

Water or moisture           Omnivores

Soil or water chemistry (e.g., P, NH4+)   Detritivores

etc.        etc.

All of these vary over space/time

By and large, this set of environmental factors is important almost everywhere, in all ecosystems.

Usually, biological communities include the "functional groupings" shown above. A functional group is a biological category composed of organisms that perform mostly the same kind of function in the system; for example, all the photosynthetic plants or primary producers form a functional group. Membership in the functional group does not depend very much on who the actual players (species) happen to be, only on what function they perform in the ecosystem.

Processes of Ecosystems

This figure with the plants, zebra, lion, and so forth illustrates the two main ideas about how ecosystems function: ecosystems have energy flows and ecosystems cycle materials. These two processes are linked, but they are not quite the same (see Figure 1).

Philippines makes climate change resolutions

25 January 2011 [MediaGlobal] In the Philippines, floods and landslides marked a traumatic entry into 2011. Affecting more than 1.3 million people and causing approximately $28 million worth of property damage, the calamity of these disasters attests to the devastating consequences of poor urban planning, especially with the emerging hazards of climate change.
Set along the Pacific typhoon belt, the 7,107 islands that comprise the Philippines are persistently besieged by natural disasters. Last year’s 11 tempests caused massive destruction, especially October’s category-five “super” Typhoon Megi assault on Manila and the nearby provinces of Isabela and Cagayan. Within a month, floods submerged these regions before they had a chance to recover.
Just after the December holiday season, another heavy downpour incited flashfloods and landslides, turning New Year preparations into rescue operations. The National Disaster Risk Reduction and Management Council (NDRRMC) reported a human toll of 53, which included deaths from drowning, electrocution, and from the collapse of a chromite mine tunnel outside of Butuan City.
“This brought to the fore the institutional weaknesses of the country’s urban management systems,” pointed out UN Human Settlements Programme (UN Habitat) spokesperson Sharad Shankardass. “These problems were compounded by climate change, requiring a completely new dimension to urban planning and management.”
The recent calamities are the worst that the country has seen in decades. A tragic 2006 landslide wiped out the village of Guinsaugon in Southern Leyte, killing more than 1,000 people. In September 2009, flashfloods devastated Manila in the aftermath of Typhoon Ondoy, which poured down an alarming 455-millimeter rainfall in 24 hours, surpassing the 250-millimeter record of 2005’s Hurricane Katrina.
The persistent vulnerability of urban areas is due mostly to the lack of useful data for reliable planning, implementing faculty for mandated strategies and programs, and a central institution for urban planning and management, explained Shankardass to MediaGlobal.
Urban centers in the country evince poor structural planning, with deficient drainage systems and waterways, inadequately-constructed infrastructures, and unregulated settlements. In terms of atmospheric facilities, most of these cities lack early warning devices and compatible equipment to project impending risks.

“These problems were compounded by climate change, requiring a completely new dimension to urban planning and management,” Shankardass stated.
The downpours are especially ominous, considering the La Niña phenomenon, an unusual increase of heavy rainfall, which the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) forecasts to peak in the first quarter of 2011.