Bacteria Reproduction Essays - Bacteriology, Bacteria, Prokaryote

Bacteria Reproduction Bacteria are microscopic singular celled organisms grouped in the prokaryote kingdom. They have a seemingly simple internal structure but that is not so the internal structure of a bacterium is quite complicated . Bacterial growth is generally studied in cell cultures by "visible count" estimation which shows an apparent growth curve. (Stephenson 50) The growth curve shows the stages of bacterial growth within a cell culture. (Thimann 623). Bacteria can survive in a number of different extreme environments from extreme heat to little water. Bacterium have a internal structure that is more complicated than it seems at first. The first part of the bacterium is the plasma membrane which is a selectively permeable barrier that is the boundary of the cell. (Prescott 40) The next portion of a bacterium is the cytoplasmic matrix. The cytoplasmic matrix is the substance lying between the plasma membrane and the nucleoid. (Prescott 45) Although it is generally featureless in a microscopes it can be packed with ribosomes and is generally highly organized. (Prescott 45) The next one is the nucleiod of a bacterium.(Prescott 40) This is the area within a bacterium in which the genetic material of the cell is located. (Prescott 49) The nucleiod itself is not defined by a membrane but is an irregularly shaped region of the cell. (Prescott 50) The gas vacuole of a bacterium is used for buoyancy in aquatic environments. (Prescott 40) This is demonstrated by filling a bottle with Cyanobacteria stopping it with a stopper and then hitting the stopper with a hammer.(Prescott 45) The sudden pressure increase causes the gas vacuole to collapse so the bacteria sink to the bottom of the bottle.(Prescott 47) The inclusion bodies within a bacterial cell are storage for different substances such as carbon, phosphate and other substances. ( Prescott 40) The cell wall of Bacteria gives the bacteria shape and protects it from the outside environment. ( Prescott 40) The flagella of bacteria are tail like appendages of cells that are used for movement. (Prescott 40) The method usually used for estimating the growth of bacteria is the " viable count" method. (Stephenson 50) When the total count of the bacteria is plotted against time it shows a growth curve. (Stephenson 50) Such curves are divided into eight differing phases.(Thimann 623) The first phase of the growth curve is an initial stationary phase in which no growth occurs. (Thimann 623) The second phase is one of an increasing rate of growth these first two phases constitute the lag phase. (Thimann 623) The reason for the lag phase is this when you first put bacteria in a culture they need time to get into a state of growth called the embryonic stage. (Thimann 625) This stage can be identified by observing the cells. The bacteria grow to a greater size than normal. (Thimann 625) The third phase is called the logarithmic growth stage.(Stephenson 50) During logarithmic growth stage the rate of increase remains constant and the cell size returns to normal. (Stephenson 50) The fourth phase is one of decreasing cell growth with many cells dying off. (Thimann 623) The fifth phase of cell growth is where the cells reach the maximum population of bacteria that the medium can support with growth and death balanced out. (Thimann 624) The sixth phase is one of increasing death rate. (Thimann 624) The seventh phase is the "logarithmic" death phase which is the inverse of the logarithmic growth phase. (Thimann 624). The eighth and final phase of the growth curve is one of decreasing death rate. (Thimann 624) In this stage a small amount of bacteria can live almost indefinitely provided that the medium is still inhabitable. (Thimann 624) This curve shows the bacteria's limitations dependent on your constants and variables within the growth curve experiment. The level of aeration the temperature and nutrient levels all are variables that lead to different results in this experiments. Bacteria can grow in many harsh conditions. One type of classification for bacteria is based on the temperature at which a bacterium can survive. The thermopile bacteria are bacteria that can survive at temperatures of forty-two to one hundred degrees Celsius or more.(Edwards 2) These bacteria are generally found around hot geological sites such as volcanoes and geysers.(Edwards 2) Another class of bacteria are the Acidophiles. Acidophiles are Bacterium that can survive and reproduce within an extremely acidic environment.(Edwards 34) Their environments are highly acidic soils in mining and geothermal areas.(Edwards 34) Oligotrophs are bacteria that can survive on little organic matter such as carbon (Edwards 93) They

A Review of Intelligence for an Age of Terror (Treverton, 2009). The WritePass Journal

A Review of Intelligence for an Age of Terror (Treverton, 2009). Introduction A Review of Intelligence for an Age of Terror (Treverton, 2009). IntroductionConclusionsReferenceRelated Introduction This book by Treverton (2009) is argued here to be a vitally important area of work that looks specifically at the way in which the use of intelligence has naturally had to change as a result of modern society. Interestingly, although there is a clear aim not to apportion blame specifically for the recent atrocities, the author indicates that he feels there is a link between the United States and their flawed approach to intelligence and the high profile terror attacks that have taken place in the US. Significantly, the author is very careful not to apportion blame or finger point and maintains a balanced and critical approach when trying to establish a link and to look at the role of intelligence. Main Arguments Presented In this book, the author actually goes on to break down the failures, in order to try to identify the impact that the specific shortcomings are having on the magnitude and nature of the target of the threats. He recognises in this analysis that, in many cases, the intelligence approaches are enshrined in the Cold War security approaches of looking at the organisation and the tactical decisions of the intelligence offerings, rather than focusing on the actual threats that are being faced in the current climate (Riley et al 2005). One of the main aspects of the book which provides added value to the information that is being presented is that, although the author spends time identifying the failings, he also spends some considerable time looking at the way in which the changes he suggests could be implemented, in practice. As a professional with experience in the field, this shows and adds considerable value to what would otherwise be a potentially academic discussion. In order to achieve this, the author takes a very pragmatic view, with the initial stage being to look at the nature of the risks that are looking at being targeted from intelligence operations. He states that recognising the threats is the first step towards then being able to recognise the way these should be handled. It is this pragmatic approach which looks at both the practical reality and the academic study that makes this book so informative in the area of intelligence being used in the terror context. The author follows themes and after identifying them he then goes on to look at how intelligence should be reformed to deal with the modern challenges. In order to identify the best way to deal with intelligence and to look at the reform of intelligence culture, there is a need first to consider the actual route of the threat and where it emanates from. One underlying argument and theme which is presented by the author here and which adds particular value to the discussion, in the opinion of the reviewer, is to look at the role of the nation state as being at the root of the changing dynamic. For example, during the Cold War, the focus of terror attacks was typically nation states and as such the intelligence gathering focussed on these entities. As time has passed, the nation states have become much more than simply target areas. Nation states can often offer a great deal of information that adds to the knowledge and understanding of the general issues of intelligence. Increasingly however in the modern context, the non-state actors play a vitally important role and it is argued by the author here that much of the role of the modern intelligence officer is to look at understanding the distinctions and various nuances that exist within these non-state actors, in such a way that their own motivation and actions can be better understood (p.141) Linked to this thread of discussion and again a vitally important aspect of the role of intelligence is that there are considerably more individuals, groups and entities that are involved in the area of intelligence gathering to prevent terrorism. With this increased number of people involved, the author places a great deal of focus on the idea that, whilst agencies may well have the technology to share information, they do not necessarily have the appropriate policies in place and therefore the underlying policies need to be reviewed, if modern challenges are going to be dealt with. As an overall position, the author maintains that there needs to be a reasonable means of supplying information across all relevant actors and to ensure that the information which is being presented is relevant and measured, so that the correct people can react quickly and appropriately. By focusing on some of the practical difficulties faced in the current climate, it is argued here that the author gains a much higher degree of legitimacy than other academic analyses in this area may achieve; in particular, the author recognises that it is necessary to take a balance between the need to improve security, but also to provide privacy and security for individuals’ information (Snowden, 2002). He notes that paying attention to legality and legitimacy is in fact increasingly important to the anti-terror efforts and that there then needs to be a total review of the policies associated with anti-terror activities as the main way of managing and combating such issues. He supports this by suggesting that factors such as encouraging intelligence authorities to create a method whereby they can share information with other entities in a constructive and balanced manner is as important, if not more so, than the actual intelligence itself. Conclusions On balance, it is argued that this book presents an interesting and well informed opinion on the modern challenges facing the intelligence industry. By being an author who has practical experience in this area, it is suggested that this allows the text to gain legitimacy and also to take a more rounded view of the challenges being faced. Finally, providing practical and well backed up suggestions for the future means that this text presents real value to the area of intelligence and counter terrorist activities. It is concluded, therefore, that this is a well-balanced and informative text that fills a gap within the current understanding of the intelligence industry. Reference Riley et al., (2005) State and Local Intelligence in the War on Terrorism, Santa Monica, CA: RAND Corporation Snowden, D (2002) Complex Acts of Knowing: Paradox and Descriptive Self-Awareness, Journal of Knowledge Management, Special Issue, September. Treverton, G. (2009). Intelligence for an Age of Terror. Cambridge: Cambridge University Press.