Bacteriophage Lambda Lysogenic Cycle Biology Essay

Bacteriophage Lambda Lysogenic Cycle Biology Essay Viruses are tiny agents that cause infections in a wide range of hosts including animals, plants, bacteria and other viruses. In particular, viruses that infect bacteria are called bacteriophages, bacterio meaning â€Å"bacteria† in Greek and phage meaning â€Å"to eat†. Bacteriophages are able to undergo lytic and lysogenic cycle to replicate; however, most undergo one or the other cycle to replicate. An example of a bacteriophage that is able to undergo both cycles is bacteriophage lambda (phage lambda). Bacteriophage lambda infects only the bacterium Escherichia coli strain k-12. Phage lambda is unique in its ability to turn replication genes on or off depending on the host’s condition. When E. coli is infected with phage lambda and the cell dies due to an environmental factor, the phage will switch from the lysogenic to the lytic replication cycle. Bacteriophage lambda was discovered by Esther Lederberg in 1950 while she was working in a laboratory with E. c oli strain k-12. Lederberg is considered a pioneer of bacterial genetics; she was also an immunologist and microbiologist. She flourished academically, receiving a doctorate from the University of Wisconsin where she worked with many other pioneers of microbiology, genetics and immunology, including: Andre Lwoff, Edward Lawrie Tatum, George Wells Beadle, Frances Crick and James Watson. While at the University of Wisconsin, Lederberg was using ultraviolet light on E. coli strain k-12 to mutagenize that specific strain of the bacteria. After prolonged exposure to the ultraviolet light, the bacteria stopped growing and its condition slowly began to deteriorate. An hour and a half after the exposure to the ultraviolet light ceased, the bacteria began to lyse (burst). This led Lederberg to the discovery of bacteriophage lambda. The E. coli sample that Lederberg was using was infected with bacteriophage lambda. The phage was not detected because it was in the lysogenic cycle, which meant that the phage was a prophage, and thus that the phage genome was integrated within the bacterial genome. Bacteriophage lambda sensed that the bacteria was about to die, so it switched its replication genes on and converted to lytic replication, therefore causing the cell to lyse and release the phage into the environment. Lederberg is also accredited with the discovery of induction; the process of when the lysogenic cycle is terminated and the lytic cycle is activated due to adverse conditions caused by ultraviolet light. Lederberg, along with her team of researchers, was awarded the Pasteur award in 1956. Viruses have many different anatomical structures depending on what kind of cells they infect. The anatomical feature that is similar throughout all bacteriophage is the capsid. The capsid or head is a shell made out of protein that contains DNA or RNA, depending on the virus. The capsid also contains some internal proteins. The capsid can have many different configurations, from a polygon-shaped sphere, like an icosahedral, or a rod-shaped helix. The main functions of the capsid are that it allows the virion to attach to its host via special sites on the surface, contains the internal proteins that allows the virus to penetrate the host cell membrane, which enables it to inject the infectious DNA or RNA into the host cell’s cytoplasm, and that it provides protection for the nucleic acid from the environment and digestion by enzymes. The capsid has structural subunits called capsomers that may contain one or many polypeptide chains. Some viruses have a secondary structure that protects the capsid itself, this is called an envelope. Not all viruses have an envelope; the envelope is made up of glyco-proteins and surrounds the entire capsid for optimum protection. The envelope has two lipid layers intermingled with protein molecules, a lipoprotein bi-layer, and also has a mixture of material that consist of the viral origin and some material from the me mbrane of the host cell. Besides a capsid, some viruses also contain a tail that is attached to the capsid which helps the virus penetrate the host cell’s outer membrane and allows the virus to inject the DNA or RNA into the host cell. The tail consists of two main structures: the tail fibers and a tail sheath. The tail fibers are tiny leg like formations that help the phage attach on to the bacterial cell by clinging on to the surface receptors. The tail sheath is a tube like structure that runs from the capsid to the tail fibers; the tail sheath digs into the cell membrane of the host and the DNA or RNA travels down the sheath and into the cytoplasm of the host and the infectious cycle begins. For viruses without tails, specialized spikes are protruding directly from the capsid that play a similar role to that of tails; the spikes are made up of proteins and help the virus invade the host cell. Bacteriophage lambda has a capsid with an icosahedral configuration that is 55 n anometers in diameter that contains 350-575 capsomers or subunits of 37,000 Daltons; the capsomers are positioned in groups of 5 and 6 subunits or pentamers and hexamers. The tail is 180 micrometers long and contains a single tail fiber that is 25 nanometers long. Bacteriophage lambda does not possess an enveloped capsid.

Business Management Proposal Essay Example | Topics and Well Written Essays - 1500 words

Business Management Proposal - Essay Example (Rigby, 2005) The basic aim of the proposal would be to develop a modification of law based on the marketing plan for Visual Management Systems Ltd for expansion into the southern States of the country. Apart form this central theme it would also be looked upon there should be enough opportunity and specified methods to penetrate and expand market segments for the company in relation to the use and capability of the CCTV related security technology from the parameters of marketing and for this aspects too your moral and legislative help is extremely needed. The world is in the midst of an all-purpose technological revolution based on CCTV related security technology, defined here as visual security, software related surveillance techniques, and CCTV related security equipment. The macroeconomic benefits of the CCTV related security technology revolution are already apparent in some economies, especially the United States and United Kingdom. Historical experience has shown that such revolutions have often been accompanied by financial booms and busts, and the CCTV related security technology revolution has been no exception. But, while spending on CCTV related security technology goods is likely to remain stable ... While technological change is an ongoing process, there are periods during which technological progress is especially rapid, resulting in new products and falling prices of existing products that have widespread uses in the rest of the economy. Such periods are generally identified with CCTV related security technology revolutions. (Hood, 2003) Earlier examples include textiles production and steam power in the industrial revolution, railroads in the nineteenth century, and electricity in the early twentieth century (the automobile could also be included, but its development was relatively gradual). The effects of such revolutions have generally occurred in three (often overlapping) main stages. First, technological change raises productivity growth in the innovating sector; second, falling prices encourage capital deepening; and, finally, there can be significant reorganization of production around the capital goods that embody the new technology. (Hall, 2006) The growth of the CCTV related security technology sector in the 1980s was an important development for the economy, but it spurred relatively little policy or media interest. True, CCTV related security technology was recognized as a driver of comparative advantage for the US and the UK and there were a few initiatives involving industrial policy and military preparedness, CCTV related security technology was of interest primarily to specialists. (Prawer, 2005) A unique confluence of forces certainly came together in the 1990s: rapid technological advances in the technology sector; widespread recognition that security could be used to comparative advantage as well as process it; the rapid

Nurse Roles & Functions Essay Example | Topics and Well Written Essays - 250 words

Nurse Roles & Functions - Essay Example Alternatively, nurses also play instrumental roles in CQI by ensuring that they follow the prescribed rules and systems set by the healthcare organization. Nurses must also improve their service provision approaches to avoid errors experienced in the workplace. The various types of organizational hazards encountered while working at a local hospital entail injuries, accidents, inadequate equipment and congestion (Vincent, 2010). The preventive strategies that should be implemented to prevent workplace-related injuries include the provision of safety gears like gloves, cleaning the wards and the procurement of more equipment. The safety issues in health care, such as prevention of blood borne illnesses is to ensure that nurses use gloves when attending to patients (Vincent, 2010). The prevention of needle stick equipment is by disposing all the used syringes at the correct dump bins where children and other people cannot access them. The prevention of back injury can be handled by avoiding carrying of heavy items or placing medical equipment at places where others cannot overstretch to reach them (Vincent,

November Rain :: English Literature Essays

November Rain I pass a shop display and view my reflection in the glass-a well built man of thirty with a tanned complexion, dark eyes and hair. I seem to have a certain charm and grace that can-and does-go down very well with the ladies. I open the door, pull out the chair, buy the drinks and surprise them with gifts. I stay at their flats after a night out; I leave my belongings there. You could say that I’m just a bachelor with a lust for living-if I wasn’t married. I’ve been married ten years and it feels like 40. It was great at first-nights out in clubs, at parties, flirting, teasing and loving each other, or at least touching each other. We had no children to hold us down and a whole world of fun to experience. Then, it stopped. I can’t remember when, where or how. What I know is that for ten years I’ve been bound to this woman and all the practices of such a colourful marriage have been tried and are jaded; the feelings no longer evident. She is abrupt with her answers and retorts for the most part and otherwise silent, so we both have seemed to have taken our own practices elsewhere, fallen into another person’s arms and experience the same feelings anew. I walk on by, get into my shining convertible (which is now speckled with signs of yet more rain) and speed away. I step into the hall of my home in Chicago, Illinois, and into the kitchen. Rain cascades down the windowpane, such has been the case for much of Novmber. There is a plate of spaghetti Bolognese waiting right on the counter for me. I heat it up, and take it to my study, letting the aroma waft right past my nose. Turning on the stereo, I settle back in my leather, over-cushioned armchair with a long, relaxed sigh. The stereo always starts on Classic Rock radio station. Hard rock, that’s what I love best. I open the Wall Street Journal, sub-consciously listening to the music in the background. Bliss. â€Å"Blackwater shares have†¦Ã¢â‚¬  (Music in background): â€Å"When I look into your eyes, I can see a love restrained, but darlin’ when I hold you, don’t you know I feel the same†Ã¢â‚¬ ¦I look up to see the source of this slightly familiar song: â€Å"November Rain† by Guns N’ Roses. â€Å"†¦both know hearts can change, and it’s hard to hold a candle in the cold November rain†¦Ã¢â‚¬ 

Advertisement: Advertising and Media Literacy Education Essay

Children cannot escape them. They stare at them from every nook and corner. The highways, the roadways, streets all have hoardings, banners, posters screaming about the goodness of the product they are advertising. Newspapers have columns and columns, pages and pages devoted to advertisements. Greatest curse of modern times for children is advertisements. Advertisement reminds the children to buy new things and no wonder they are brainwashed and pester their parents to buy it for them. However, advertisement is a good way to tell about the products. They inform the children about new technology or trend. Similarly, advertising may also have a negative impact on today’s youth. Junk food ads encourage children to eat unhealthy food, which is often portrayed as fun. See more: Defining research problem and setting objectives Essay Another advantage of advertising is it gives media literacy education. Children need to know that they are being bombarded by messages (both good and bad) every day. They need to be taught how to discern these messages from an early age and to decide how to react to the messages. They also teach them other good things. In addition, advertising is making children feel that without their product, you’re a loser. Kids are very sensitive to that. They become most emotionally vulnerable. Advertisement also educates children and is very informative. How would children cope without news and catching up with what goes around in the society? For instance, sometimes kids do not understand what the commercial is about and they are not yet fully developed. If they see something that is not appropriate then they will start telling other kids of their age which is not okay for them. Kids are exposed to things that can be misunderstood and take things negatively. What is more is that the advertisements targeting children’s aim to promote the products and services, which cater for children’s needs and have no damaging intention at all. Overall, I believe that advertising has both advantages and disadvantages. However I believe that in most cases the benefits outweigh the disadvantages. I do believe that ads should be more strictly monitored, especially during children’s viewing hours. Harsher penalties should apply to people who infringe any laws and more people should be hired to patrol exactly what is played on ads. Children see, children do.

Strategic Management Strategic Planning - 1460 Words

When it comes to strategic management many defined it as the management that link strategic planning decision-making. It is sometimes over looked unless it is specifically brought up when it comes up in strategic planning. With this management in place an organization can achieve its long-term goals. As well as plan out its future goals and endeavors for the organization to be successful. Strategy itself has many forms and levels as well; it is broken down into smaller parts of planning. For strategy there are usually four parts to it. Having the overall Idea is the first step, it consist of everything what you are trying to accomplish and what is trying to get done. After that you go into how to do it and break down the procedure of what you are trying to do as well. After you have the planning and operational level, when you plan and let the operation of the plan go into effect. Implementation is the last step when you actually put all of your planning into affect and see the re sults of it as well. Strategic management consists of six key elements, using these tools can assure a successful strategic plan. These tools are; Vision, Mission, Core Value, Strategic areas of Focus, Strategic Goals, and Action Plan. When creating a successful strategic management plan you must include these elements. Each is necessary in creating a blueprint that will not crumble. Having the correct vision of a strategic plan can help you plan out and create a mental picture for theShow MoreRelatedStrategic Planning : Strategic Management1707 Words   |  7 Pages1. How do you conduct your strategic planning? Strategic planning is a joint endeavor that involves field operations, headquarters and mission support. The agency’s strategic planning practices entail brainstorming new ideas, implementing innovations and reflecting on past practices in developing action plans to improve daily functions, upcoming operations and immediate response actions to crisis situations. T he operational plan or warning order provides mission critical information regarding equipmentRead MoreStrategic Management : Strategic Planning986 Words   |  4 Pagesit comes to strategic management many defined it as the management that link strategic planning decision-making. It is sometimes over looked unless it is specifically brought up when it comes up in strategic planning. With this management in place an organization can achieve its long-term goals. As well as plan out its future goals and endeavors for the organization to be successful. Strategy itself has many forms and levels as well; it is broken down into smaller parts of planning. 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Otherwise, without a clear strategy, an organisation could face difficulties in achieving its mission, as every business venture requires an elaborate approach, skilfulRead MoreStrategic Management : Strategic Planning3081 Words   |  13 PagesIntroduction Strategic planning in business management is a highly important portion of management as it involves development of plans to ensure growth, success, and above all else, profit. If not analysed correctly a poorly formed strategic plan can result in reduced profit margins. When analysing strategic planning as a discipline, there theorists which develop frameworks to assist managers in how to develop a strategic plan. Of these, Porter’s Five Forces Framework (5FM) is among the most influentialRead MoreStrategic Planning And Strategic Management Essay2359 Words   |  10 Pagesthe overall strategic management process. According to Abraham (2012), â€Å"Strategic management is nothing less than steering and managing a company to be successful over time—not just for the next quarter or year, but for the long term.† (sec. 1.1). Many questions will be answered during this process. â€Å"What direction should the company go in, what industry will it compete in, and w hat products or services will be featured?† (Abraham, 2012, sec. 1.1). Strategic planning and strategic implementationRead MoreStrategic Planning And It Management1424 Words   |  6 PagesStrategic planning is the process of determining a companys long-term goals and then identifying the best approach for achieving those goals (Wikipedia). This process aligns strategic planning with overall organization planning by assessing organizational objectives and strategies, setting the organizational mission and mandate, assessing the external environment and setting policies, objectives and strategies (Wikipedia). A study completed in 1999 revealed that less than 40% of US businesses includedRead MoreStrategic Planning As An Effective Tool Of Strategic Management1486 Words   |  6 Pageslook at the processes of strategic planning as an effective tool of strategic management in business organizations. It finds for effective strategic planning it requires top level managersâ€℠¢ to take an active role in defining the strategic direction of the organization. It requires good working relationships between the planning staff, managers, and the top level management team. In creating an environment which recognizes strategic planning as a tool of strategic management, we will review one of theRead MoreStrategic Management and Planning3167 Words   |  13 PagesStrategic Planning and Management Development Throughout the business industry the people who are most associated with the business process has found strategic planning and management development requires constant shifting back and forth between long-run and short-run thinking (Dess and Miller, 5). 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Who Killed Princess Diana And Dodi AlFayed Free Essay Example, 1000 words

Who Killed Princess Diana and Dodi Al Fayed Lecturer: Who Killed Princess Diana and Dodi Al Fayed The press court settled on the limousine driver and the paparazzi as the killers of Princess Diana and Dodi AlFayed. Few evidences were given that lead to this theory. First and as A. Cowell wrote in his article â€Å"Negligent Driving Killed Diana, Jury Finds† at the New York Times that the driver who also was the Ritz’s hotel head of security was off duty for few hours before he had to drive Princess Diana and Al Fayed. Following that, when the driver was off duty, he was drinking alcohol, and this has been reassured when his blood samples were tested; by this, the court concluded that the driver was drunk when he was driving. When the driver was trying to escape from the paparazzi, he was not on his healthful mind; therefore he could not escape well. In 2008, the article â€Å"Jury: Princess Diana, Boyfriend Dodi Al Fayed Killed by the Driver, Paparazzi† on Fox N ews adding the mentioned theory, that the fast moving limousine was slammed into a concrete pillar while being chased by the photographers on cars and motorcycles. We will write a custom essay sample on Who Killed Princess Diana And Dodi AlFayed or any topic specifically for you Only $17.96 $11.86/pageorder now They similarly reported that the blood tests of the driver result showed that he was three-times over the national drunk-driving standard. They also add that Diana and Dodi were not wearing seat belts and this was a key cause to their death, as seat belts prevented many fatal injuries reducing them to 45% as the Highway Safety Research Center reported. The Fox news continues by saying nine photographers were charged, but the chargers were thrown by 2006, not stating why they were thrown. Therefore, the royal family, paparazzi, Al Fayed enemies, and Diana herself are all argued reasons on the semi-mysterious death of Princess Diana. Gossips were arguing that the British throne was the stirrer to Princess Diana’s death. The media had reported this story in different ways. Emery wrote in his article Who Killed Princess Diana that Diana by marrying the Muslim, Dodi AlFayed, would embarrass the royal family, as he will be the stepfather of Princes William and Henry. This would make sense since the royal family is Christian and it will hurt their reputation if they had a Muslim member in their family. However, Emery mentioned that close friends denied the marriage rumors. According to Emery, † It was suggested that an agent of MI6, the British intelligence service, was present at the scene, posing as a member of the press. It was suggested that a mysterious vehicle, a white Fiat Uno, was used by the conspirators to block the limousines path, forcing it to collide with the pillar† (1).