Ecological niche From Wikipedia

Ecological niche From Wikipedia, the free encyclopedia Jump to: navigation, search Black smokers create ecological niches with their unusual environment In ecology, a niche (CanE, UK /? ni / or US /? n? t? /)[1] is a term describing the way of life of a species. Each species is thought to have a separate, unique niche. The ecological niche describes how an organism or population responds to the distribution of resources and competitors (e. g. , by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters those same factors (e. . , limiting access to resources by other organisms, acting as a food source for predators and a consumer of prey). [2] The majority of species exist in a standard ecological niche. A premier example of a non-standard niche filling species is the flightless, ground-dwelling kiwi bird of New Zealand, which exists on worms, and other ground creatures, and lives its life in a mammal niche. Island biogeog raphy can help explain island species and associated unfilled niches. Contents[hide] * 1 Grinnellian niche * 2 Eltonian niche * 3 Hutchinsonian niche * 4 Parameters * 5 See also * 6 References * 7 External links| [edit] Grinnellian niche The word â€Å"niche† is derived from the Middle French word nicher, meaning to nest. The term was coined by the naturalist Joseph Grinnell in 1917, in his paper â€Å"The niche relationships of the California Thrasher. â€Å"[3] The Grinnellian niche concept embodies the idea that the niche of a species is determined by the habitat in which it lives. In other words, the niche is the sum of the habitat requirements that allow a species to persist and produce offspring. For example, the behavior of the California Thrasher is consistent with the chaparral habitat it lives in—it breeds and feeds in the underbrush and escapes from its predators by shuffling from underbrush to underbrush. This perspective of niche allows for the existence of ecological equivalents and also empty niches. For example, the Anolis lizards of the Greater Antilles are a rare example of convergent evolution, adaptive radiation, and the existence of ecological equivalents: the Anolis lizards evolved in similar microhabitats ndependently of each other and resulted in the same ecomorphs across all four islands. [edit] Eltonian niche In 1927 Charles Sutherland Elton, a British ecologist, gave the first working definition of the niche concept. He is credited with saying: â€Å"[W]hen an ecologist says ‘there goes a badger,' he should include in his thoughts some definite idea of the animal's place in the community to which it belongs, just as if he had said, ‘th ere goes the vicar. ‘†[4] The Eltonian niche encompasses the idea that the niche is the role a species plays in a community, rather than a habitat. edit] Hutchinsonian niche Squirrels in public parks may have a different ecological niche than those with less human contact. The Hutchinsonian niche views niche as an n-dimensional hypervolume, where the dimensions are environmental conditions and the resources that define the requirements of an individual or a species to practise â€Å"its† way of life. The niche concept was popularized by the zoologist G. Evelyn Hutchinson in 1957. [5] Hutchinson wanted to know why there are so many different types of organisms in any one habitat. An organism free of interference from other species could use the full range of conditions (biotic and abiotic) and resources in which it could survive and reproduce which is called its fundamental niche. However, as a result of pressure from, and interactions with, other organisms (i. e. inter-specific competition) species are usually forced to occupy a niche that is narrower than this, and to which they are mostly highly adapted. This is termed the realized niche. The ecological niche has also been termed by G. Evelyn Hutchinson a â€Å"hypervolume. † This term defines the multi-dimensional space of resources (e. . , light, nutrients, structure, etc. ) available to (and specifically used by) organisms. The term adaptive zone was coined by the paleontologist, George Gaylord Simpson, and refers to a set of ecological niches that may be occupied by a group of species that exploit the same resources in a similar manner. (Simpson, 1944; After Root, 1967. )[citation needed] Hutchi nson's â€Å"niche† (a description of the ecological space occupied by a species) is subtly different from the â€Å"niche† as defined by Grinnell (an ecological role, that may or may not be actually filled by a species—see vacant niches). Different species cannot occupy the same niche[citation needed]. A niche is a very specific segment of ecospace occupied by a single species. Species can however share a ‘mode of life' or ‘autecological strategy' which are broader definitions of ecospace. [6] For example, Australian grasslands species, though different from those of the Great Plains grasslands, exhibit similar modes of life. [7] Once a niche is left vacant, other organisms can fill that position. For example, the niche that was left vacant by the extinction of the tarpan has been filled by other animals (in particular a small horse breed, the konik). Also, when plants and animals are introduced into a new environment, they have the potential to occupy or invade the niche or niches of native organisms, often outcompeting the indigenous species. Introduction of non-indigenous species to non-native habitats by humans often results in biological pollution by the exotic or invasive species. The mathematical representation of a species' fundamental niche in ecological space, and its subsequent projection back into geographic space, is the domain of niche modelling. [8] What is the ecological niche of a Slater? In:Insects [Edit categories] Answer: the slater's lives in dark places. uptake water by eatting food Rate This Answer Upper Hutt College Year 13 Biology Slater Study Achievement standard: biology 3. 1 Introduction to experiment: In this investigation of the ecological niche of the woodlouse, I chose to experiment the amount of soil moisture that the slaters tend to prefer. I chose this aspect, as moisture is a vital part in the survival of this small creature. Internet sources provided information of the woodlice that shows that they are from crustacean descent and formerly aquatic even though now they are terrestrial rather than water dwelling. Slaters are generally found in moist, dark places with decomposing plant matter. Enter Slater Diagram From two diagrams it is shown the area of the slaters lungs are near the rear end of the woodlouse and located inside the pleopod, these are where the gills are hiding. The Slater is a creature that receives its oxygen through moisture in its surroundings, which is why I chose to do an experiment on moisture and in which amount of water is most suited to their survival and not a threat. The Woodlouse also has no waxy layer on its body which means desiccation is easy compared to other bugs, this is another reason why the slater need moisture in its environment. Aim: The aim of this investigation is to experiment using woodlice and test on which amount of soil moisture they prefer. Hypothesis: I believe that the more soil moisture there is, the more slaters will be found in that area. Independent Variable: The independent variable of this experiment will be the amount of water that is to be added to the soil. This variable will be measured using millilitres and a measuring cup. The range of values for this will be: 0mls, 25mls, 50mls, 75mls and 100mls. To keep this experiment as fair and accurate as possible, the water will be the exact amount by myself getting down to eye level and pouring the water in little amounts to get the precise amount of water needed. Dependent Variable:

Application of social learning theory in psychology research Essay

‘Explaining substance use among Puerto Rican adolescents: a partial test of social learning theory’ is an article by Holly Ventura Miller, Wesley G. Jennings, Lorna L. Alverez-Rivera and J. Mitchell Miller. The article is a 2008 publication in the Journal of Drug Issues Volume 38, issue number 1. In this study, Miller et al (2008) seek to use social learning theory to understand substance use among Puerto Rican adolescents as part of the larger Hispanic group. The importance of social learning is assessed through finding out the effect of differences in an individual’s description of substance use as compared to the description that peers have. This study is based on the view that most adolescents who have friends who are in substance abuse also become substance abusers. Perceptions about drug abuse also seem to be similar with those held by the peers. Social interactions of the youths therefore seem to play a big role in learned behavior and perceptions. Miller et al (2008) have reviewed considerable literature on social learning theory more so the aspect of differential association in acquisition of socially unacceptable behavior. A cross-cultural application of social learning theory forms the center of this study where a group (288 youths) of Puerto Rican adolescents is chosen as the study sample. This study specifically focuses on how peer and personal perception of substance use influence alcohol, cigarette and marijuana use. The survey-type of study was carried among school going youths aged 14-19 years in San Juan, Puerto Rico. The subjects were selected from public and private schools with the sample size from public schools being considerably higher compared to that from private schools (69% versus 31%). The survey was conducted using questionnaires where several variables were assessed. Questionnaires administered in public schools were written in English whereas those issued in public schools were in Hispanic. The study excluded subjects who did not report being Hispanic since ethnicity was a very crucial variable. The adolescents were assessed of their behaviors as regards to alcohol abuse, cigarette smoking and marijuana use. Predictor variables were social learning (definitions on substance abuse) and sex. The control variables in this study were age and belonging to single-parent family. After statistical analyses (logistic regression analyses), it was found out that youths in private schools had a greater lifetime substance use and reported peer influence in the use of the three substances. In addition, males were likely to be involved in use of the three substances under study as opposed to females in both types of schools. In private schools, a significant difference in substance use was noted to exist between males and females. It is also notable that cigarette use among females in public schools was influenced by their views of smoking cigarettes as a favorable behavior. This was also the case with private school males. Personal definitions were also found to play a big role in alcohol consumption. Marijuana use was mainly due to the influence of peers’ definition as opposed to personal definition. Miller et al (2008) therefore concluded that if personal definitions of substance use are favorable, the likelihood of substance abuse is high. Peer definitions are also significantly important determinants of substance abuse as evidenced by marijuana use among Puerto Rican adolescents. Sex is also a determinant factor in influencing substance use. Article 2 The article ‘social learning, self control, and substance abuse by eight grade students: at tale of two cities’ by L. Thomas Winfree Jr. and Frances P. Bernat is a 1998 publication in the Journal of Drug Issue volume 28, issue number 2. In this study, Winfree and Bernat (1998) examine the effectiveness of the social cognitive theory and self control theory in predicting level of substance abuse among a group of eight graders in a large versus a small city. Among the substances the substances that the eight grade students are assessed of include alcohol, cigarettes, and marijuana among others. This sample is selected from Phoenix, Arizona and Las Cruces, N. M. the cities are choice for this study due to differences in types of crimes thus the authors of this study challenge that the two theories cannot be used to predict substance abuse among the two groups of youths. Winfree and Bernat (2008) argue that the social learning theory is viewed as being able to predict how people develop delinquent behaviors, as well as the environment that is likely to predispose one to delinquent behaviors. As such, it is viewed that substance abuse by youths can be predicted by the social learning theory as long as the social environment of the youth is well understood. On the other hand, Winfree and Bernat (1998) argue that the self control theory indicates that the level of self control determines human behavior especially in consideration of factors such as self interest and tendency to seek pleasure and not pain. In their study, Winfree and Bernet (1998) carried out a wide cross-sectional study in 11 localities including Phoenix and Las Cruces. The subjects who participated in this study gave an informed consent through either parents or guardians. Data was collected through the use of questionnaires and the surveyors helped the students in understanding the questions thus improving accuracy of data collected. Dependent variables in this study were use of different substances within the past one year. Social learning independent variables included neutralization, guilt, positive reinforcement and negative pushers. Self control independent variables included parental monitoring, impulsivity and risk-taking. After performing regression analyses, it was evident that there was a low level of substance abuse among Phoenix students who said that they would feel very guilty if their engaged in substance abuse. Higher levels of substance abuse in Phoenix sample was identified among students who agreed greatly to neutralizing statements about negativity of crime. In terms of self control, there was higher substance use among students who reported higher risk taking tendencies. However, parental control and impulsivity did not provide enough data for evaluation. In Las Cruces, it was observed that youths who had seen gangsters and viewed gangsters as having better lifestyles were likely to abuse substances. The same happened with neutralization of negativity of crime. Guilt was not a big determinant of substance abuse in Las Cruces. Conclusively, Winfree and Bernet argue that social learning theory and self control theory can be used to evaluate delinquency in adolescents. From the above two articles, social learning theory emerges as an important tool for predicting substance abuse. Counselors stand to benefit from the understanding of the application of social learning theory in this context since they can be able to associate a certain substance abuse problem to the social influences of the client. By identifying the source of the substance abuse problem using the social learning theory, the counselor is able to provide a way out of the delinquency or substance use. This would include subjecting favorable social environment and statements such that the substance abuse behavior is taken as a negative rather than a positive thing. It would also be helpful for the counselor to suggest a geographical relocation (e. g. school transfer) as an important way of creating the best environment (drug/crime-free environment) for adolescents. References Miller, H. V. , Jennings, W. G. , Alverez-Rivera, L. L. and Miller, J. M. (2008). â€Å"Explaining substance use among Puerto Rican adolescents: a partial test of social learning theory. † Journal of Drug Issues 38(1): 261+. Web. 15, July 2010. Questia. com. Winfree, L. T. and Bernat, F. T. (1998). â€Å"Social learning, self control, and substance abuse by eight grade students: at tale of two cities. † Journal of Drug Issue, 28(2): 539+. Web. 15, July 2010. Questia. com.

Consumer behaviour in Cambodia Dissertation Example | Topics and Well Written Essays - 6250 words

Consumer behaviour in Cambodia - Dissertation Example This section will comprise the justification and description of the research methods that are to be put into practise in order to determine the consuming behaviour in Cambodia. The methods that will be adopted have been explained in detail so that a suitable pathway can be determined. The chapter will shed light on the research design, the methods and the philosophical approaches of the study. The chapter then proceeds to highlight the sampling method and the sample size of the study. The target population or the intended participants who will be approached will be also highlighted. In addition, this chapter will also emphasize on the process of data collection and how the collected data will be analysed in the subsequent section. Lastly, the study will state the ethical issues associated with the study and the limitation of the study. 3.2 Research Philosophy It is necessary for a researcher to make certain assumptions regarding the nature of reality which is to be studies (Daniel, 2 010). Apart from that, assumptions are also made about the knowledge produced and the research perspective. Figure 1 The figure above summarizes the approaches that can be used by the researchers in a research study. The approaches have been summarized in the form of epistemology, ontology, theory, perspective, techniques and methods. Each of these different approaches entails to a different way of performing the research. In general there are two research philosophies namely interpretivists and positivist (Blaxter, Hughes and Tight, 2006; Guba and Lincoln, 2005). Positivism is a philosophy of research which is based on the view that sociology must use the natural methods (Tobin and Joseph, 2006). However, that does not mean only use of experiments as there are several problems associated with experiments. The biggest one comes in the form of ethical violations. The researcher who believes in positivist philosophy believes that research works must be conducted with the help of quant itative methods. They principally aim to measure the social structures (Mehrens and Lehmann, 1987). On the other hand, interpretivists or anti positivists takes the other way round. According to their point of view, human being perceives and reflects on that basis and scientific studies are not appropriate for the study of society. They also believe that unlike objectives human being has the ability to alter their behaviour. Hence, the inference is that in order to understand the social action, it is necessary to understand the meaning and reason people perceive about the environment around them (Abbott, 2010; Connaway and Powell, 2010; Gordon, 2007; Snieder and Larner, 2009; Wilson, 2010). Another important finding of the study is that researchers who follows interpretivism philosophy believes that social research must be conducted with the help of qualitative method (Saunders, Lewis and Thornhill, 2009; Browne, 2006). This study seeks to investigate the consumer behaviour pattern of Cambodia and hence it clearly

Art Essay Example | Topics and Well Written Essays - 500 words - 48

Art - Essay Example This means the figure represent humanity in general. Borofsky prompts the viewer to compare the sculpture with what happens in our daily lives. In as much as the figures face away from one another, they are able to communicate through holding hands. This simply means regardless of the differences people might have in life, they still need each other for survival (Borofsky 1). The image of two people holding hands could have various meanings. For example, it could demonstrate children playing in a field. One child is a head of the other while the other one is running after him. The holding of hand is a symbol of love and affection between the children. This is a message to all viewers that they should love one another. It also means that people should always be active and happy in their daily lives. The images demonstrate people who are running while holding hands. The runners could be sportsmen in the field. This means it is important for sportsmen to work as a team while in a competition. They should also demonstrate the true spirit of sportsmanship by helping any injured person in the field. Lastly, they should know competition is not about being enemies but rather it is a game that demonstrates who is well equipped to win a duel One of the images has a person running while the remaining person has a raised hand though standing. The raised hand could be intended to direct the running person. This encourages viewers to avoid trouble and run away whenever it is necessary. This means that viewers ought not to fight back when wronged. Instead, they should walk away in peace in order to avoid confrontation that could be more disastrous resulting into loss of life. Borofsky starts his work with drawings. This is usually a demonstration of his thoughts that he transforms into an object. The object is usually an initial idea about human life. The idea could be happiness, love or sadness. He then converts the ideas into images that could be understood by

Critically analyse how changes in the role of information systems have Essay

Critically analyse how changes in the role of information systems have determined their use in the evolving competitive landscape of many industries - Essay Example The very first word that springs to our mind when we discuss Mp3 technology is "copyright". Inefficient copyright mechanisms can make or break the Music Industry as apparent from the yesteryears hype created by the Music Industry suing for piracy of their music through Mp3 versions of their copyrighted material. The digital age seems to have compromised the concept of copyright material and has had negative outcomes for the publishing, music and the computer industries. An important example of this is the peer-to-peer file sharing system of copyrighted music. The Napster and Grokster cases are a good illustration of the legal response of the industries .The copyright industries themselves have responded with new business strategies by providing legal download services.1The internet has been famously defined as a network of networks, and the denser these networks become; the more complicated it becomes to prevent the bane of copyright infringement and other intellectual property viola tions from occurring. 2Even though the courts have been willing to intervene where there has been an infringement of copyright, the practical difficulties of managing copyright violations arise whenever the "sheer scale" and "speed" of the internet causes high speed reproduction of the material to be achieved without actually being detected.Therefore my strategic analysis of the Mp3 technology involves the stress on DRM technologies to prevent heavy losses to the industry.Further discussion entails the emergence of Ecosystems with in this industry bringing about a collusion of the Singers,Record Labels and online Information service providers as well as the role played by governmental and legal agencies to protect the financial interests of the industry as illegal downloading and burning continue to compromise the industry's ability to invest in the new music talent of tomorrow. When assessing the purchasing trends of any industry it is pertinent to note that the buyers will display certain types of buying behaviors. The aim of assessing the competitive landscape of the Music industry it would be worth employing a Marketing Mix (MM) strategy to tap into the preferences of the consumer base(Laudon,and Laudon 2008).The diagram below shows five dimensions of the customer buying behaviour. Figure: THE FIVE KEY DIMENSIONS OF BUYING BEHAVIOUR (Jobber, 1998) The answer to these questions can be given through direct contact with consumers (in a retail environment) and increasingly by using marketing research for the Music Industry.However there are other issues at stake.The use of information systems for the sale purchase and management of the Music industry has harmed it more than benefitting it.No doubt the online music stores are a testimony to the blessings of the cost efficient era of E commerce and allow Ecosystems to develop in the cyber world thereby integrating the industry to bring about cheaper goods and services. (Laudon,and Laudon 2008).The era of digitalization for this industry began very positively as the dot.com bubble encouraged many small and large businesses to open online stores.Significant record labels also clamored to advertise their merchandise and labels online.The scale and magnitude of advertisement potential available online brought about a temporary boom in the Online Music industry while bringing fringe bene fits for the offline record labels but the entry of Kazaa, Grokster, EDonkey, and Bit-Torrent and their

How does Harold's article on The Sopranos either complicate or further Essay

How does Harold's article on The Sopranos either complicate or further the arguments put forth in Garrett's text about TV Anti-Heroes and what they represent in our society - Essay Example This argument has been furthered by â€Å"A Man Never Never Land†, this is because the article postulated that the heroes of today have colossal psychological flaw; this is because they have a self-serving lies. They are normally filled with self-pity, venality, sloth, and lust. They are regarded to be self-deceiving and morally blind. Additionally, they are deemed obnoxious, unfaithful, and brash. This is supplements the argument of Garrett which that â€Å"We live in Post-World War II era†. According to Tony Soprano, the issue of morality was white and black; it was compared to Nazis vs. us. The Nazis were rated as bad people. However, in the war of today, the wrangles and conflict are ambiguous, including using torture. â€Å"A moral Never Never Land: Identifying with Tony Soprano† argued that people now have to employ morally unacceptable mechanism of fighting terrorists and the moral ambiguity is engraved in the upcoming anti-hero. Harold further explains that to add to the heroes that were heavily flawed, there are pressure from the prison system, big business, bureaucracy, and the structure of power that is full of bribe in conforming to forces that are not good. Rather they have rebelled against themselves, even if using the trickery a nd dishonesty could be portrayed as heroic. â€Å"A moral Never Never Land: Identifying with Tony Soprano† further argues that there is confidence crisis in the democratic leaders and processes that created a surrounding of nihilistic, disaffected, and cynical hero. This turning point during the Morally Deformed Hero Regime, happened with â€Å"A moral Never Never Land: Identifying with Tony Soprano†, when millions of people loved him. The ruthless sociopath and businessperson became close that the moral boundaries blurred in the regime of the hyper-competitive Darwinism. In the docket, both Nazis and Us failed in effecting the change in

Service Reflection Essay Example | Topics and Well Written Essays - 500 words

Service Reflection - Essay Example I once worked at an after school child program where it was my responsibility to help children with their homework. Being a person without very good English skills, I was worried that the children would not understand what was being said, so I was only able to help with mathematics. Mathematics is a universal language so I thought this would make up for my lack of English-speaking skills. It was my responsibility in this role to help children achieve their greatest successes, even when the children were difficult and hard to manage. This is part of Jesus’ teaching on servant leadership: To do unto others as one would have done unto yourself. I tried to remember this when working with small children, as they need a person who is willing to provide patience and understanding even when they are naughty. By not immediately responding to my own attitudes and concerns about my own weaknesses in English teaching skills, I realized that the children had many positive qualities that would help me reach them better. If I had not drawn on these teachings provided by the Holy Bible, I would not have been able to drop my own fears about insecurity. This is why I am thankful for having servant leadership qualities that were given to me by faith and conviction. When working with the children, I realized that they had many needs. Some of these needs were emotional and others were to have help in order to give them better academic successes. Only a good leader that understands the servant leadership beliefs of religion would be able to reject their own needs in order to provide a better learning experience for the small children. When working with one specific child named Patrick, who was very difficult to teach because of his behavior and attitudes, I realized that the many lessons inspired by Jesus Christ would help me to reach him better. I suddenly realized during the experience that this child needed someone who would be tolerant

How teaming in the workplace has affected the culture of the working Essay

How teaming in the workplace has affected the culture of the working person - Essay Example Group formation might be temporary or permanent. Following are some of the main types of groups: Roles are sets of behaviors that individuals occupying specific positions within a group are expected to perform. These roles might be assigned (e.g. managers or other work related roles) or pre-determined (like father, mother, etc). Roles help in clarifying responsibilities and obligations of the group members. A status is a position or a rank within a group. People are sensitive to status because it is related to desired outcomes (e.g. salary and perks). High status people have a higher access to key resources relating to survival. Sometimes even physical features play an important role in gaining a certain status (e.g. a beautiful secretary). People can boost their status by behavior (e.g. intimidation, anger and threat) Norms are the rules within a group indicating how its members should or should not behave. Adherence to norms is a necessary condition for gaining status and other rewards controlled by groups. This forms the basis of organizational behavior. It comprises everything that causes the group members to remain in the group. It leads to depersonalized attraction, i.e. liking for other group members stemming from the fact that they belong to the group and embody or represent key features (like hard work or creativity, etc). These include effects upon performance resulting from the presence of others. Increased and positive effects occur due to collaboration, while decreased and negative effects take place due to dependence upon others. This theory says that the presence of others induces conflicting tendencies to focus on the task being performed and on the audience. The more the audience, the more the conflicts and thus, the more nervous you get. Working together with others to obtain shared goals is called co-operation. They are achieved by making others

Cover letter Essay Example | Topics and Well Written Essays - 250 words - 5

Cover letter - Essay Example My most recent internship at the Commonwealth of Pennsylvania Capital provided an opportunity to develop strong office assisting skills. Prior to this experience, I spent several summers working with several other firms in their customer service departments, which enhanced my ability to work in a fast paced environment and resolve problems, which are all listed in your preferred qualifications for this position. From these past work experiences, I was also able to develop on my interpersonal skills while socializing within the teams we were in as well as in the entire firm. Granted this opportunity and basing on my ability to work, I believe I will be able to help GWSB to achieve its organizational objectives as well as cement a position as an organization in the corporate settings. Besides, I am quite familiar with the Microsoft Office applications, strong customer care skills and am also motivated to work with a diverse group of constituents (Ryan, 20). I would appreciate discussing this position with you in the near future. I would be glad to receive an interview call from you asking me to appear before your recruitment board. If you require any additional materials or information, I would be happy to avail it. Thank you for your

Books And Reading Essay Example for Free

Books And Reading Essay Topical Vocabulary 1. Categorisation: Children’s and adult’s books; travel books and biography; romantic and historical novels; thrillers; detective stories; science fiction/fantasy; non-fiction; pulp fiction. absorbing; adult; amusing; controversial; dense; depressing; delightful; dirty; disturbing; dull; fascinating; gripping; moralistic; obscene; outrageous; profound; whimsical; unputdownable. 2. Books and their parts: paperback and hardback; binding; cover; jacket; title; epigraph; preface; the contents list; fly leaf; bookplate; blurb; a beautifully printed book; a tome bound in leather; a book with dense print/ with loose pages. 3. Reading habits: to form a reading habit early in life; to read silently/incessantly/avidly/voratiously; to read curled up in chair; to read a child/oneself to sleep; to be lost/absorbed in a book; to devour books; to dip into/glance over/pore over/thumb through a book; to browse through newspapers and periodicals; to scan/ skim a magazine; an avid/alert/keen reader. 4. Library facilities: reading rooms and reference sections; the subject/author/title/on-line catalogue; the enquiry desk; computer assisted reference service; to borrow/renew/loan books; CDs and video tapes; rare books; to keep books that are overdue; books vulnerable to theft; to suspend one’s membership; to be banned from the library. I. Use the thematic vocabulary in answering the following questions: 1. Which books are you reading now? 2. Where is your favourite place to read? 3. Who is your favourite novelist? 4. Who is your favourite character? 5. Which contemporary author do you most admire? 6. Which is the first book you can recommend reading? 7. Which school text did you most enjoy? 8. What is your favourite children’s book? 9. Which book would you like to see filmed? 10. What is the most difficult book you have ever read? II. Work in groups. Find out about the last book each of your partners has read and make notes on these points: Author and title Type of book and what’s it about Reason for liking it Reason for recommending it to others III. Work in pairs. Choose the best alternative to complete these sentences: 1. Oliver Twist is a classic work of English . Literature non-fiction letters editions 2. The plot of the story was very exciting, but I didn’t find the . Persons people characters figurers 3. This book is a special edition for foreign readers, so there’s a(n) . Appendix glossary introduction preface table of contents 4. A novel is usually divided into several . Chapters units sections passages 5. If you need to find some information in a non-fiction book, look in the . Atlas blurb catalogue diary index review 6. Cambridge University Press is the of the book you’re reading. Author editor printer publisher 7. A great novel has a good plot and a strong . Communication meaning message significance 8. The book was marvelously and it was a joy to read. Stylistic tedious well-written wonderful 9. Ernest Hemingway is one of my American writers. Best favourite ideal most popular 10. The thriller was so exciting that I couldn’t . Let it down look it up pick it up put it down 11. Even the characters in the book are really interesting. Less minor small tiny 12. I’d like to that book when you’ve read it. Borrow hire lend loan IV. In these sentences three alternatives are correct and two are wrong. Choose the best three alternatives for each: 1. The character in the book is called Oliver. Central main principal principle top 2. I enjoy her books because her style is so very . Dull entertaining readable tedious true-to-life 3. I found that the characters in the story were very . Amusing believable informative likeable thrilling 4. There were so many twists in the plot that I didn’t really think it was . Accurate authentic convincing realistic true-to-life 5. She doesn’t read any fiction because she prefers reading . Biographies short stories textbooks non-fiction science fiction 6. I can’t books like those – they just send me to sleep. Bear carry enjoy stand suffer V. Fill in the gaps in these sentences with suitable words: 1. You can borrow books from a or buy them from a . 2. A writer can also be called an . 3. I can’t afford to buy the book in hardback, so I’ll wait till it comes out in . 4. I can’t remember the of the book, but I know it had a yellow . 5. A book that tells somebody’s life story is called a . VI. Match each word in the column with the explanation: Ballad, biography, novel, drama, poem, fairy tale, poetry, story, rhyme, novelette a) a story in prose, long enough to fill in one or more volumes, about either imaginary or historical people; b) piece of creative writing in verse form, especially one expressing deep feeling or noble thought in beautiful language, composed with the desire to communicate an experience; c) simple song or poem, especially one that tells an old story; d) the art of a poet, poems; e) tale about fairies of imaginary origin; f) branch of literature dealing with the lives of persons; g) play for the theatre, radio or TV; h) verse for small children characterized by sameness of sound of the ending or two more words at the ends of lines of verse; i) short novel (story in prose); j) account of past or imaginary events. VII. Read the following extract and make with your groupmates the list of the books you would like to read while travelling: The Book- Bag Some people read for instruction, ad some for pleasure, but not a few read from habit. I belong to that company. Let us admit that reading is just a drug that we cannot get along without. Books are necessary to me and I never traveled far without enough reading matter. But when I am starting on a long journey the problem is really great. I have learnt my lesson. Once I fell ill in a small town in Java and had to stay in bed for three months. I came to the end of all the books I had brought with me and knowing no Dutch had to buy the schoolbooks from which intelligent Javanese, I suppose, got knowledge of French and German. So I read again after twenty-five years the plays of Goethe, the fables of La Fontaine and the tragedies of Racine. I have the greatest admiration for Racine, but I admit that to read his plays one after the other requires a certain effort in a person who is ill. Since then I have made a point of travelling with a large sack full of books for every possible occasion and every mood. There are books of all kinds. Volumes of verse, novels, philosophical works, critical studies (they say books about books are useless, but they certainly make very pleasant reading), biographies, history; there are books to read when you are ill and books to read when your brain want something to work at; there are books that you have always wanted to read but in the hurry of life at home have never found time to; there are books to read at sea; there are books for bad weather; there are books chosen solely for their length, which you take along when you have o travel light, and there are the books you can read when you can read nothing else. (from W. Somerset Maugham) VIII. See how many authors and titles you can match: For Whom the Bell Tolls Charlotte Bronte A Perfect Stranger Charles Dickens Airport Walter Scott Sister Carrie Dan Brown Tom Sawyer Daphne du Maurier Pride and Prejudice Arthur Hailey Martin Eden Danielle Steel Of Human Bondage Ernest Hemingway Alice in Wonderland Mark Twain Ivanhoe Lewis Carroll Rebecca Jack London David Copperfield Theodore Dreiser Jane Eyre Somerset Maugham The Da Vinci Code Iris Murdock Black Prince Jane Austen IX. Read the text and agree or disagree with the statements below: An English author once wrote: â€Å"Some books are to be tasted, others to be swallowed or digested. † This quotation tells us how to read books of different kinds. Most travel books are to be tasted; it’s enough to dip into them and read bits here and there. If you are fond of crime stories (A. Christie, G. Simenon and the rest of modern favourites) you will read them quickly, you’ll â€Å"swallow† them. And then there are books that you’ll read slowly and carefully. If a book’s on an important subject, and a subject you’re interested in, you’ll want to chew and digest it. And you’ll want to weigh what the author says and consider his ideas and arguments. 1) Reading English fiction with a dictionary is very dull. 2) If the book is very exciting, you â€Å"swallow† it. 3) Nobody reads reference books for relaxation. 4) Reading thick science fiction books is tiring. 5) Very intelligent people don’t read detective stories. 6) Non-fiction books can’t be inspirational. 7) Travel books give you a lot of useful information. 8) Unfortunately many young people are not in the habit of reading poetry. 9) Great book-lovers never lend their books. 10) Lots of people buy books for their bright and beautiful jackets. 11) Bookcases and bookshelves are the best kind of decoration for a living-room. 12) It’s of no use collecting book issues of magazines and newspapers. X. Read the following passage and say if you agree with the author: Some people think that as more and more people have their TV-sets in their homes, fewer and fewer people will buy books and newspapers. Why read an article in the newspaper, when the TV news can bring you the information in a few minutes and with pictures? Why read a novel, when a play o television can tell you the same story with colour picture and action? Why read the biographies of famous men and women, when an hour-long television programme can tell you all that you want to know? Television has not killed reading, however. Today, newspapers and magazines sell in very large numbers. And books of every kind are sold more than ever before. Books are still a cheap way to get information and entertainment. Although some books with hard covers are expensive, many books are published today as paperback books, which are reasonably cheap. A paperback novel, for example, is almost always cheaper than an evening at the cinema or theatre, and you can keep a book forever and read it many times. Books in the home are a wonderful source of knowledge and pleasure and some types of books should be in every home. Every home should have a good dictionary. Every home should have an atlas of the world, with large clear maps. It might be expensive, but a good encyclopedia is useful, too, because you can find information on any subject. In addition, it is useful to have on your bookshelves other non-fiction books such as history books, science textbooks, cookery books, books about medicine and health, etc. It is equally important to have some fiction on your shelves, too. Then you can relax with a good story, or from time to time you can take a book of poems off your shelves and read the thoughts and feelings of your favourite poets. XI. Choose the best answer according to the information in the passage: 1. Which is easier to get the news from? a) newspaper b) the television 2. Which is usually quicker? a) to read a biography of a famous person b) to watch a TV programme about a famous person 3. Which is usually cheaper? a) a paperback b) an evening at the cinema 4. Which is usually cheaper? a) a paperback b) a hardcover book 5. Which is it most important to have in your home? a) non-fiction books, such as dictionaries and encyclopedias b) fiction, such as novels, short stories and books of poems c) a mixture of both: good non-fiction and your favourite fiction XII. Discuss the following questions with your partners: 1. Were your parents worried that you watched too much TV when you were younger? 2. Did you find TV more interesting than anything else when you were at school? 3. Programmes on what subject do you like most of all? 4. Can you learn all you want on TV? 5. Do you think you get more information from books or TV? 6. Is it easier for you to memorize facts watching TV or reading books? 7. What do you like more to read books or to watch TV? XIII. Different people enjoy reading for different reasons. You will read five people saying why they like reading novels. Which of them says that novels a) are good for improving language skills? b) make them forget their problems? c) add some adventure to their life? d) teach them how to act in certain situations? e) increase their knowledge of other cultures? Reading Novels Ricky: Oh, I love novels, especially if they have a good plot. I started reading them when I was 12, encouraged by my parents who were hoping I’d be a writer myself. As it happened, reading so much at an early age had an effect on my studies, my compositions were always very good! And I still read at least one novel a week. My own life isn’t terribly exciting, apart from my work, which is very interesting, nothing much happens. In the novels I read there’s always a lot going on, lots of thrilling events, and I can share in the experiences and problems of the characters. Ella: Well, I used to read only short stories. That changed when I moved to a new city and found myself in a job I didn’t really enjoy. I would get back home at about 5p. m. , make some supper and sit down to read a novel for the rest of the evening. Many of them are pretty unbelievable stories, and not particularly well-written. It’s not as if you can imagine yourself in any of those situations, but the thing is they take my mind off whatever’s worrying me. I’ve had long conversations about this with friends who think I should read better quality staff, but I know what I’m doing. Sally: Why I like reading novels? I remember as an adolescent, I used to read novels just so as to see how my favourite characters solved their problems. I thought I could then apply that to my own problems! And I’m not ashamed to say that’s still the case, that’s what I’m looking for in the novels I read, and that’s my reason for reading them. I always choose novels that are in a clear style, because I find complicated language difficult. And also I like the stories to be about countries and cultures I know well, because then I can understand the characters better. Tom: I think reading novels is helping me a great deal in my studies, and although I haven’t got much spare time, I always make a point of reading a couple of hours in the evening. I’m in my last year at secondary school, and frankly, reading novels is an excellent way of learning how people live in other countries, how they communicate with each other, what problems they have. That’s why I prefer novels with characters who are true to life, not the ones who have impossible adventures. I’m very lucky because my best friend also likes reading and we can often discuss what we’ve both read. Alex: I like reading novels because they help me develop the ability to write myself. I used to have real problems in producing a good piece of writing. It wasn’t that I lacked ideas, no, my teachers always said my compositions were interesting. But I couldn’t get my tenses right. That’s where reading novels helped. I don’t think you can learn much about other things from novels, because the situations are usually so unrealistic. Some people say that’s OK, if your life’s boring, you need the excitement of fiction. Well, my life’s exciting enough, so that’s not my problem. 1. Do you like to read novels? Why? 2. Do you think that reading makes a person intelligent? XIV. Comment on the following: 1. A house looks gloomy and joyless without books. 2. If the book is worth reading it is worth buying. 3. Books and friends should be few and good.

Concurrency Control In Distributed Database Systems Information Technology Essay

Concurrency Control In Distributed Database Systems Information Technology Essay Concurrency control is a very important issue in distributed database system design. This is because concurrency allows many transactions to be executing simultaneously such that collection of manipulated data item is left in a consistent state. Database concurrency control permits users to access a database in a multiprogrammed fashion while preserving the illusion that user is executing alone on a dedicated system. Besides, it produces the same effect and has the same output on the database as some serial execution of the same transaction. Concurrency control in distributed system is achieved by a program which is called scheduler. Scheduler help to order the operations of transaction in such a way that the resulting logs is serializable. There have two type of the concurrency control that are locking approach and non-locking approach. In term of locking approach, two-phase lock is widely used and purpose for centralized or distributed database system. Before distributed database systems accessing some part of database, it must adopt a locking mechanism such as each transaction has to obtain a lock. After that part is locked by other transaction, the access request will be block and the transaction who making reauest has to wait. Two-phase locking will cause the deadlock problem. This locking induces high communication cost because of the deadlock problem. Whereas in term of non-locking approach which is divided into two type which are Timestamp ordering (TO) and Serialization Graph Testing (SGT). Timestamp ordering utilizes unique transaction timestamp for determining the serialization order. It divided into three different modes that are basic, conservative and optimistic modes. For Serialization Graph Testing, it has been most attractive log class until 1987 because it is known as the largest known class of serializable logs. There are some limitations that can found in those two approaches. However, there are some solution that can used to solve the problem and will be discuss more detail in the below. 2. Type and the issue of concurrency control 2.1 Two -phase locking Two -phase locking is a widely used concurrency control technique to synchronize accesses to shared item. Each data item has a lock associated with it. The scheduler will first examine the associated lock before a transaction (T1) may access a data item. If there is no transaction holds the lock then the scheduler will obtains the lock on behalf of T1. When another transaction T2 hold the lock, the T1 has to wait until T2 to gives up the lock. The scheduler will give the T1 the lock after the T2 release the lock. Scheduler must ensure that there is only one transaction can hold the lock at a time and only one transaction can access data item at a time. They are two types of locks associate with data item that is read locks and write locks. Figure 1 below show that the transaction T1 and T2 follow the two-phase locking protocol. Figure 1: Transaction T1 and T2 with 2-phase locking protocol However, there is an important and unfortunate property of two-phase locking schedulers is that they are subject to deadlocks. For instances, the classic deadlock situation in which neither of two processes can proceed that is one must release a resource and the other one needs to proceed. Besides that, deadlock also arises when the transaction try to strengthen read locks to write locks. To ensure that there is no transaction is blocked forever, the scheduler needs a strategy for detecting the deadlock. In addition, two-phase locking is suffer from sensible delays due to a node needs to send message to all nodes and must receive acknowledgement from all nodes to discover a deadlock. The messages will exchange between nodes to get decision of transactions commit. The whole system will stop since not discover the deadlock immediately and a natural of distributed system make deadlock treatment very difficult. Moreover, the message that due to commit and deadlock treatment make high traffic on network which is makes need of special kind of networking. Time Figure 2: A spatial schedules of T1 and T2 in state of deadlock T1 wait for T2 to release read lock on y2 T3 wait for T1 to release read lock on x1 T2 wait for T3 to release read lock on z3 Figure 3: A wait-for graph for the spatial schedule of Figure 2 There are two type of graph that show as above which is a spatial schedule of T1 and T2 in the state of deadlock. Another graph show that the wait for graph for the spatial schedule of the figure 2 above. Each node of the graph represent the transaction, the edges represent the waiting for relationship. Furthermore, concurrency control also deals with starvation. The starvation occurs when a particular transaction consistently waits or restarted and never gets a chance to proceed further. In a deadlock resolution it is possible the same transaction may consistently be selected as victim and rolled-back. This type of limitation is inherent in all priority based scheduling mechanism. The wound-wait scheme a younger transaction may always be aborted by a long running older transaction which may create starvation. Besides that, the two phases in locking method also may cause to dirty read and cascading abort. The problem of dirty read is arises when assume T1 and T2 are executed interleave. For this condition, the T1 will get the exclusive locks for record. Supposedly, T1 release locks immediately after doing updates while T2 acquires that locks and does its update. If the T1 fail before it commits due to certain of reason, then it will return value to original value. T2 will continue to its execution with uncommitted data and this will cause an error on the system result. On the other hand, the problem of cascading abort arises when if a transaction aborts. There may have some other transaction already used data from an object that the aborted transaction modified it and unlocked it. If this happen, any such transaction will also have to be aborts. 2.2 Timestamp ordering technique Timestamp is a monotonically increasing variable indicating the age of an operation or a transaction. The larger of the timestamp values indicate that more recent event or operation. Timestamp ordering technique concurrency mechanism were considered suitable for distributed database systems since transaction to be rolled back can be determined locally at each site. It involves a unique transaction timestamps in place of conventional locks. This technique is based on the idea that an operation is allowed to proceed only if all the conflicting operations of older transaction have already been processed. For instance, when a transaction accesses an item the system will check whether the transaction is older than the last one which is accesses the item. If this is the case that transaction proceeds, otherwise ordering is violated and the transaction is aborted. Besides that, the serializability of the transaction is preserved and requires knowledge about which transaction are younger tha n the others. In the implementation of a distributed timing system, each site in the distributed system contains a local clock or a counter. This clock assumed to tick at least once between any two events. This event within the site is totally ordered. If the total ordering of event at different sites, it need to assigned a unique number to each site and the number is concatenated as least significant bits to the current value of local block. Moreover, each message contains the information about the local time of their site of origin at which the message is sent. There are many concurrency control method on timestamp ordering technique. One of the method is basic timestamp ordering (BTO) which is for each data item x, the largest timestamp of any write operation on data item x and the largest timestamp of any read operation on data item x which are denoted by R_TS (x) and W_TS (x) respectively. The basic timestamp ordering technique is easy to distribute and the transaction to be aborted will immediately be recognized when the operation are being scheduled. This type of method will not deal with deadlock problem because the locks are not used and operations are blocked. Hence, an atomic commitment mechanism is necessary to provide the reliability. 3. Improvement of issue concurrency control 3. 1Deadlock resolution The preceding implementation of two-phase locking makes the transaction to wait for unavailable locks. When the waiting is uncontrolled will cause a deadlock. The situation of deadlock can be characterized by wait-for graph, that graph indicates which transaction is waiting for which other transaction. There are three type of general technique are available for deadlock resolution that are deadlock detection, deadlock prevention and timeout strategies. 3.1.1 Deadlock Detection Deadlock detection is a transaction wait for each other in an uncontrolled manner and is only aborted if a deadlock occurs. It can be detected by explicitly constructing a wait-for graph and searching it for cycles. Victim which is one transaction on the cycle will abort when cycle is found and thereby breaking the deadlock. There are a few victim selection criteria will be consider. First is the Current Blocker, this current blocker will pick the transaction that blocked the most recently. Secondly, Random Blocker which is a process of picks a transaction at random from the participants in the deadlock cycle. Third is the Min Locks that is to pick a transaction that is holding the fewest locks. Fourth is the Youngest which is picked the transaction with the most recent initial startup time. Lastly is the Min Work and responsible to pick the transaction that has consumed the least amount of physical resources (CPU + I/O time) since it first began running. In order to minimize the cost of restarting the victim, usually the victim is based on the amount of resource that use by each of transaction on the cycle. Each of the two-phase lockings scheduler can be easily construct the waits-for graph based on the waits-for relationships local to that scheduler. But this is not efficient to characterize all deadlocks in the distributed system. To increase the efficiency, more global wait-for graphs have to combine with local waits-for graph. For the centralized two-phase locking will not have this type of problem since there only consist of one scheduler. In order to construct global waits-for graph, there consist of two techniques which are hierarchical and centralized deadlock detection. For the hierarchical deadlock detection, the database sites are organized into hierarchy with deadlock detector to each node of the hierarchy. Deadlock divided into many sites. Deadlock involve a single site are detected at that. Whereas deadlock involve more than two sites of the same region detected by the regional deadlock detector. On the other hand, one site is designated the deadlock detector in the centralized deadlock detection. Every few minutes, each scheduler has to send its local wait-for graph to the deadlock detector. Then the deadlock detector combines the local graph into a system wide waits-for graph by constructing the union of the local graph. Although both of the technique mention above differ in detail but it involve periodic transmission of local waits-for information to one or more deadlock detector sites. 3.1.2Deadlock Prevention Deadlock prevention is a cautious scheme in which transaction is restarted when the system is afraid that deadlock to be occurring. In the process of deadlock prevention, the scheduler will test the requesting transaction which is name (T1) and the transaction that currently owns by the lock (T2) when a lock request is denied. When T1 and T2 pass the test, T1 is permitted to wait for T2 as usual. Otherwise, one of the two is aborted. There are a few prevention algorithms that are Wound-Wait, Wait-Die, Immediate-Restart and Running Priority. In the Wait-Die prevention algorithm, if a lock request from transaction T1 leads to a conflict with another transaction T2, then T1 started time earlier than T2 and block the T1 otherwise will restarted T1. The deadlock prevention will know as nonpreemptive if T1 is restarted. By this technique deadlock are impossible since there is only one transaction can be blocked by a younger transaction. In the Wound-Wait algorithm, if T1 started running before T2 then restarted T2 otherwise blocked T1. This type of algorithm is known as preemptive which is older transaction run though the system by killing any one that they conflict with and continues waiting onlt for older conflicting transaction. The scheduler must ensure that T1 wait for T2 so that deadlock cannot occur. There is a better approach can be assign priorities to transaction and to test priorities to decide whether T1 can wait for T2. If T1 has the lower priority than T2 then T1 will wait for T2. When they have same priorities, T1 cannot wait for T2 or vice versa. This test will prevents the deadlock to occur since every edge in the waits-for graph T1 has a lower priority than T2. In addition, the Immediate-Restart algorithm also will overcome the deadlock by simply restart T1 since there is no transaction is ever blocked. Besides that, preordering of resources is a type of deadlock avoidance technique that used to avoid restarts altogether. It requires predeclaration of locks which mean that each transaction obtains all its locks before execution. The priority of transaction is the number of the highest number lock on it and the data item are numbered and each transaction request locks one at a time in numeric order. Although this techniques can avoid the deadlock occur but it forces locks to be obtained sequentially which is tends to increase response time. 3.1.3 Timeout strategic In the timeout strategic, a transaction whose lock request cannot be granted is simply placed in the blocked queue. When the wait time exceeds some threshold value then the transaction will restarted. Timeout will restart transaction that involves in deadlocks in the detection strategies whereas in prevention strategic it may also restarted some transaction that are not involved in any cycle. 3.2 Strict 2 Phase Locking (S2 PL) In order to prevent cascading problem and dirty read, Strict 2 Phase Locking mechanism is apply. The executed transaction holds all its lock to the every end until it is committed or aborts. For the dirty read, the executed transaction does not release any of exclusive locks until it commits or aborts. S2PL has important role in the two phase locking problems. In first time transaction it need a lock on a data item, acquires it and all locks of a transaction released together when the transaction terminates and has a few resource wasting. Figure 4 below show the S2PL mechanism. Figure 4: S2PL mechanism 3.3 Ordering by Serialization Number (OSN) method There exists a new method for concurrency control in distributed system which increases the level of concurrent execution of transaction and known as ordering by serialization number (OSN). The deadlock is prevented by this method since it works in the certifier mode and uses time interval technique in conjunction. In order to provide serializability, it combines with time interval technique with short term locks. Scheduler is distributed and the standard transaction execution policy is assumed. The read and write operations are issued continuously during transaction execution. The write operations are performed on the private copies of the data that issue by the transaction. The transaction is certified and its operation will applied to database when a validation test is passed by the transaction at the end of transaction. Otherwise, the transaction will restart if the test validation is not passed. To find the serialization number for a transaction, the largest serialization number of certified transaction will read item x. The largest serialization number of certified transaction which have written item x will record along the data item x which is known as RSN(x) and WSN(x). There consist of four types of short term locks in this OSN method that are R-lock, W-lock, Certified Read lock, Certified Write lock. The R-lock and W-lock normally used when read or write the data item. It responsible to protect the data item forms two conflicting operations of concurrent transaction. Whereas Certified Read lock (CR-lock) and Certified Write lock (CW-lock) are used during the validation test while a transaction is searching for a valid time interval. These lock are held until either the transactions operation are applied to the database or the transaction is aborted. The deadlock of short term locks is prevented by a few steps. Firstly, R-lock or W-lock is obtained at any order. Since transaction do not require any other lock before releasing a particular R-lock or W-lock deadlock does not appear. Secondly, employing the preordering for deadlock avoidance can prevent the deadlock of the CR-lock and CW-lock respectively. Although this method requires the access set of transaction to known in advance but this disadvantage eliminated in the OSN method. This is because CR-lock and CW-lock requires by the time of certification. Besides that, if a transaction requires both CR-lock and CW-lock on data item x the system will grants them both when both of these locks are requires at once. 4. Conclusion In this study, the performance of concurrency control protocol on top of a comprehensively modeled high-speed network is evaluated. It found that there exist of some issue within the concurrency protocol such as deadlock and starvation in the two-phase locking. The weaknesses that occur in another concurrency protocol that is timestamp ordering. By the way, there are also discussing about the effective way to make improvement of the concurrency control by using three types of deadlock resolution to solving the deadlock problem. The deadlock resolution included deadlock detection, deadlock prevention and timeout strategic. Furthermore, a precise definition of deadlock in term of existence interval of an edge is given and these help provide a better understanding of deadlock detection is distributed system. Besides, this paper also discuss the complete specification of a secure version of two phase locking protocol. The interaction between the protocol and the standard failure recovery procedures were discuss and modification to the commit and restart procedures were proposed. 5. Reference Abdou R. Ali and Hany M. Harb, Two Phase Locking Concurrency Control in Distributed Database with N-Tier architecture, 2004. S. M. Wu and D. L. Pan, FUTURE TREND ON CONCURRENCY CONTROL IN DISTRIBUTED DATABASES SYSTEM DESIGN , 1988. Sang H. Son and Rasikan David, Design and Analysis of A Secure Two-Phase Locking Protocol, 1994 Shapour Joudi Begdillo, Fariborz Mahmoudi and Mehdi Asadi, Improving Strict 2 Phase Locking (S2PL) in Transactions Concurrency Control, 2007 PHILIP A. BERNSTEIN AND NATHAN GOODMAN, Concurrency Control in Distributed Database Systems, June 1981 RAKESH AGRAWAL, MICHAEL J. CAREY, MEMBER, IEEE, AND LAWRENCE W. McVOY, The Performance of Alternative Strategies for Dealing with Deadlocks in Database Management Systems, 1987 UGUR HALICI AND ASUMAN DOGAC,MEMBER,IEEE, Concurrency Control in Distributed Databases Through Time Intervals and Short-Term Locks,1989

Dream Interpretation of the Film Lost Highway Essay -- Lost Highway Mo

Dream Interpretation of the Film "Lost Highway" Cop: Do you own a video camera? Renee: No. Fred hates them. Fred: I like to remember things my own way. Cop: What do you mean by that? Fred: How I remembered them. Not necessarily the way they happened. A dream can mean everything, or it can mean nothing. According to Freud, if we take its contents seriously, it has the potential to reveal things about ourselves that we scarcely believe could be true. But often the fragmented oddness of such a vision damages its credibility, and one is left wondering how something so disjointed could contain insight of any value. Such is the dilemma with "Lost Highway," a movie seemingly bent on walking its viewers down one path, and then, when they begin to understand the nature of it all, to abruptly change course and begin anew. Hitchcock's "MacGuffin" - the term he coined to refer to the apparent plot of a story, which is merely a cover for the underlying, more important thread - is both irrelevant and vital in this film. The viewer will watch what is happening, trying to get a sense of the plot, but the plot, really, is unimportant. The very nature of plot demands a sense of linearity, and this movie lacks such a characteristic. However, th e plot is also the most important aspect of the film, because, ultimately, almost everything each character does seems to be part of a dream in the mind of the central character, Fred Madison. Consequently, what happens is not merely manifest content to be brushed aside. Hidden within it is the latent content which will give the viewer an understanding of what is happening in the mind of this man. How do we know it is a dream and not merely poor story-telling? How do we know... ...on to detail complements this approach quite well. In either case, the effect works. One of the most difficult tasks in a movie is to let the viewer inside the mind of one of its characters. This is much easier in literature, which can employ the faculties of narration and omniscience. In a film with no such leisure, a director must rely on images and dialogue alone to accomplish this feat. To visually represent the emotions of a character can only be well-executed in a few distinct ways. One such, effective way is to film the dreams and fantasies occurring in the mind of that character. Lynch's approach works, and Fred's emotional and psychical states of being are clear, if the viewer can just look past the manifest to find the rich, latent content buried beneath. Bibliography Gay, Peter, ed. The Freud Reader. New York: W.W. Norton & Company, Inc., 1989.

Energy Consumption Essay -- Renewable Energy Essays Papers

Energy Consumption Continuing expansion of the world population results in increasing demands for energy to support human existence. I will concentrate on countries that use a lot of energy from fossil fuels, as well as examine countries that are increasingly becoming dependent on alternative forms of energy, such as nuclear energy and hydroelectricity, and others including geothermal and solar energy. The fossil fuels I am going to examine are coal, natural gas, and oil. Within the sector of oil, I will specifically show the demand for petroleum imports. I will also concentrate on renewable energies, such as nuclear energy, hydroelectricity, geothermal, and solar energy consumption. Some forms of energy are rapidly depleting, such as oil, coal, and natural gas, and if countries do not increasingly diversify their reliance upon fossil fuels, there will be economic tragedies in the near future. Recognizing this problem, countries around the world are relying more and more on renewable energies, not only for the economic benefits, but also for the environmental benefits which resul t in healthier living conditions for all human beings. Coal is a fossil fuel that poses serious threats to our environment, including greenhouse gases, acid rain, and air pollutants. It has the lowest consumption rate among all fossil fuels. Among all countries, Japan had the highest consumption rate of over 150 million tonnes of oil equivalent (Mt’s). This country accounts for one forth of the world’s total coal imports, which reached 659 Mt’s (Key World Energy). Countries need to focus on alternative renewable sources of energy so they can become more self reliant. This is important because economies are so susceptible to price fluctuations, an... ...asteful way most of us use energy. So, if you want to do something personally to save the planet, think about what kind of car you own and how you use it. Works Cited 1. Academic. OFFSTATS. 22 January 2004. Key World Energy Statistics 2003. 2. Academic. OFFSTATS. 31 January 2004. International Renewables Information. 3. Academic. OFFSTATS. 31 January 2004. Statistical Review of World Energy 2003. 4. â€Å"Million Tonnes of Oil Equivalent.† 1 February 2004. 5. â€Å"Petroleum Products.† 1 Frebraury 2004. 6. Renewables in Global Energy Supply. 22 January 2004.

The Double Helix Essay -- Double Helix Essays

The Double Helix    "The discovery of the structure by Crick and Watson, with all its biological implications, has been one of the major scientific events of this century." (Bragg, The Double Helix, p1) In the story of The Double Helix, James Watson tells of the road that led to the discovery of life's basic building block-DNA. This autobiography gives insight into science and the workings within a professional research laboratory that few members of society will ever be able to experience. It also gives the reader an idea of the reality of life for one scientist and how he struggled with the problem of DNA. However, the author's style is marked by his lack of objectivity and inclusion of many biased opinions and personal prejudices.    One example of this ongoing subjective style can be seen in Watson's writing on women, particularly in his dealings with Rosalind Franklin. The fact that Watson believes that all women are good for is pleasure and keeping house can be seen in the word choice and style of several passages throughout The Double Helix. These passages' subjects include Rosalind Franklin's appearance, appeal, and acceptance of the double helix model and concept.    In the first several chapters of The Double Helix, James Watson gives detailed descriptions of the places and people who were of some importance in this charade of science. Watson wrote of his personal history and of how he arrived at the Cavendish Laboratory in Cambridge. In this laboratory was a yet-unknown thirty-five year old man named Frances Crick . When Watson joined the team at Cavendish it was to help continue studies on the structure of proteins. Some of the people in the lab that Watson mentioned were Sir Lawr... ...be shed. In comparing several passages written about Rosalind Franklin, it can be seen that Watson carried a certain style and pre-determined opinion of women and their place in society. In the first passage written about Rosy's appearance, Watson criticizes her choice of dress and then tries to blame her family for the way she turned out. The second passage dealt with Rosy as a presenter and her appeal to the audience, particularly Watson. In the final passage, Watson is shocked to find that Rosy can be rational and was not always being outrageous. By examining the amount of objective and subjective material in three of Watson's passages, it is viable that his style can be fingerprinted by his lack of objectivity and by his splashing of personal opinions.    Works Cited Watson, James. The Double Helix. WW Norton & Company, New York London. 1980.

Limitations and Contraints of Marketing Essay

Finance: Marketing costs money, having an advertisement broadcasted on television or on a radio costs a significant amount of money. Gathering research on marketing for your business will also cost a lot of money. Organisations with low finance may have to resolve on gaining data for the organisation that is â€Å"cheap† and acquired from secondary sources which a lot of the time isn’t exactly precise but it’s still better than nothing. Time Constraints: Time is extremely important for any organisations. Fashion organisations would need to time the release of new brands effectively; it’s pointless releasing a new range of winter clothing in the middle of summer. Another good example is the battle between Samsung and Apple, these two organisations will be patient and wait for the other to release information on their new product, so if Samsung released information about their new mobile being Water proof then Apple could then go away and use that information to their advantage and make their phones water proof also. Reliability of Data: Data can be acquired in many different ways, what’s important however is if the data you’re receiving is reliable or not. Primary and secondary sources are extremely important to organisations; it can be the vital difference between gaining reliable data and receiving poor data. Research on data costs money, and the better the data, the more likely the organisation will have to fork over a lot of money, which then greatly effects finance limitations and constraints. Legal and Ethical: The data protection act is the best example for Legal and Ethical Constraints. The data protection act means market researchers can only collect and hold specific data, and the data they do collect has to be kept secure and only used for lawful purposes. Any data collected has to be collected for a reason.

Pricing Strategy of Soft Drinks Today Essay

We will basically focus on the pricing strategies adopted by these two affluence companies, how the change in the strategy of one of them reflects in the strategy of the other. {text:bookmark-start} Entry barriers in soft drink Market: {text:bookmark-end} The several factors that make it very difficult for the competition to enter the soft drink market include: Network Bottling: Both Coke and PepsiCo have franchisee agreements with their existing bottler’s who have rights in a certain geographic area in perpetuity. These agreements prohibit bottler’s from taking on new competing brands for similar products. Also with the recent consolidation among the bottler’s and the backward integration with both Coke and Pepsi buying significant percent of bottling companies, it is very difficult for a firm entering to find bottler’s willing to distribute their product. The other approach to try and build their bottling plants would be very capital-intensive effort with new efficient plant capital requirements in 2009 being more than $500 million. The advertising and marketing spend in the industry is very high by Coke, Pepsi and their bottler’s. This makes it extremely difficult for an entrant to compete with the incumbents and gain any visibility. Coke and Pepsi have a long history of heavy advertising and this has earned them huge amount of brand equity and loyal customer’s all over the world. This makes it virtually impossible for a new entrant to match this scale in this market place. Retailer Shelf Space (Retail Distribution): Retailers enjoy significant margins of 15-20% on these soft drinks for the shelf space they offer. These margins are quite significant for their bottom-line. This makes it tough for the new entrants to convince retailers to carry/substitute their new products for Coke and Pepsi. To enter into a market with entrenched rival behemoths like Pepsi and Coke is not easy as it could lead to price wars which affect the new comer. {text:bookmark-start} SWOT Analysis: {text:bookmark-end} Strength: Weakness: Opportunities: Threats: {text:bookmark-start} Various cola brands products Available: {text:bookmark-end} {text:bookmark-start} Pricing Strategy: {text:bookmark-end} {text:bookmark-start} Coke – Price {text:bookmark-end}. {text:bookmark-start} Pepsi – Price {text:bookmark-end} {text:bookmark-start} Pricing strategy for Buyer and Suppliers: {text:bookmark-end} Suppliers: The soft drink industry have a negotiating advantage from its suppliers as most of the raw materials needed to produce concentrate are basic commodities like Color, flavor, caffeine or additives, sugar, packaging. The producers of these products have no power over the pricing hence the suppliers in this industry are weak. This makes the soft drink industry a cheap input industry which helps in increasing their gross margin. Buyers: The major channels for the Soft Drink industry are food stores, Fast food fountain, vending, convenience stores and others in the order of market share. The profitability in each of these segments clearly illustrate the buyer power and how different buyers pay different prices based on their power to negotiate. These buyers in this segment are somewhat consolidated with several chain stores and few local supermarkets, since they offer premium shelf space they command lower prices, the net operating profit before tax (NOPBT) for concentrate producer’s is high. This segment of buyer’s is extremely fragmented and hence has to pay higher prices. This segment of buyer’s are the least profitable because of their large amount of purchases they make, it allows them to have freedom to negotiate. Coke and Pepsi primarily consider this segment â€Å"Paid Sampling† with low margins. NOPBT in this segment is very low. Vending: This channel serves the customer’s directly with absolutely no power with the buyer. {text:bookmark-start} Effect of competition and Price War on Industry profits: {text:bookmark-end} In the early 1990’s Coke and Pepsi employed low price strategy in the supermarket channel in order to compete with store brands. Coke and Pepsi however in the late 90’s decided to abandon the price war, which was not doing industry any good by raising the prices. Coke was more successful internationally compared to Pepsi due to its early lead as Pepsi had failed to concentrate on its international business after the world war and prior to the 70’s. Pepsi however sought to correct this mistake by entering emerging markets where it was not at a competitive disadvantage with respect to Coke as it failed to make any heady way in the European market. {text:bookmark-start} Pricing Strategy used for market capitalization: {text:bookmark-end} Price is a very important part of the marketing mix as it can affect both the supply and demand for soft drinks. The price of soft drinks products is one of the most important factors in a customer‘s decision to buy. Price will often be the difference that will push a customer to buy our product over another, as long as most things are fairly similar. For this reason pricing policies need to be designed with consumers and external influences in mind, in order to effectively achieve a stable balance between sales and covering the production costs. Till the late 1980s, the standard SKU (Stock Keeping Unit) for a soft drink was 200 ml. In 1989, when Indian government opened the market to multinationals, Pepsi was the first to come in. Thums Up (a product of Parle) went up against the international giant for an intense onslaught with neither side giving any quarter. Around 1989, Pepsi launched 250 ml bottles and the market also moved on to the new standard size. When Coke re-entered India in 1993, it introduced 300 ml as the smallest bottle size. Soon, Pepsi followed and 300 ml became the standard. With large population and low consumption the rural market represented a significant opportunity for penetration and market dominance. Competitive pricing was the key. Then the capacity went from 250ml to 300ml, aptly named MahaCola. This nickname gained popularity in smaller towns where people would ask for â€Å"Maha Cola† instead of Thums Up. The consumers were divided where some felt the Pepsi’s mild taste was rather bland. In 1993 Coca-Cola re-entered India after prolonged absences from 1977 to 1993. But Coca-Cola’s entry made things even more complicated and the fight became a three-way battle. That same year, in a move that baffled many, Parle sold out to Coke for a meager US$ 60 million (considering the market share it had). Further, as the demand changed, both Pepsi and Coke introduced 1 liter returnable glass bottles. RGB 250ml 1989 Rs 8 RGB 300ml 1993 Rs 9 RGB 300ml, 1994 Rs 9 RGB 300ml 1996 Rs 11 Pet bottles 1 liter, 2 liter 1996 Rs 25, Rs 42 RGB 300ml 1997 Rs 7 Pet bottles 1 liter, 2 liter 1997 Rs 20, Rs 38 RGB 200ml, 300ml (negligible) 2002-03 Rs 5, Rs 11 Pet bottles 500ml, 1 liter, 1. 5 liter, 2 liter 2002-03 Rs 18, Rs 25 Can 330ml 2002-03 Rs 35. {text:bookmark-start} Penetration pricing: {text:bookmark-end} In the past (in 2002-03), Coke had already targeted rural consumers by bringing down the entry price (Rs 5 a bottle) for its product. Now, it has stepped up distribution of its 200-ml (priced at Rs 7 and Rs 8) returnable-glass-bottles. To surmount the penetration policy of Coke, Pepsi too came up with the same Price penetration policy by launching products like â€Å"Chota Pepsi† with the price of Rs 5 to challenge the coke product. The small size was basically used to target rural market to make new customer habitual to it. {text:bookmark-start} Conclusion: {text:bookmark-end}.

Cash Basis vs. Accrual Basis Accounting Essay

Accrual accounting doesn’t just focus on cash flows, instead, it also reflects other resources that are provided and consumed by business operations during a period. This method measures resources provided by business operations by revenue. The measure of resources used to earn revenues is expenses. The difference between revenues and expenses is net income/loss. Accrual basis net income provides a better measure of performance because it attempts to measure the resource inflows and outflows generated by operations during the reporting period, which may not provide the same amount of cash inflows and outflows. Accruals involve transactions where the cash outflow or inflow takes place in a period after the expense or revenue recognition. â€Å"Selling on credit and projects that provide revenue streams over a long period of time affect the company’s financial condition at the point of the transaction. Therefore, it makes sense that such events should also be reflected on the financial statements during the same reporting period that these transactions occur†. (Investopedia, 2013). While cash basis is the difference between cash receipts and cash disbursements from providing goods and services. For cash basis accounting, a transaction happens only when money is exchanged. â€Å"Revenues are reported on the income statement when cash is received from the customers. Expenses are reported on the income statement when cash is paid out. This is one of the problems with cash basis accounting because adjusting entries help ensure that all revenues earned in a period are recognized in that same period, regardless of when cash is received†. (Averkamp, 2004). For accrual basis accounting, â€Å"revenues are recorded on the income statement when they are earned, which more often than not occurs before cash is received. Expenses are recorded on the income statement in the period when they occur/expire which is often in a different period from when the payment is made. This method of accounting provides a better picture of the company’s profits during an accounting period because the income statement will report all of the revenues actually earned during the period and all of the expenses incurred in order to earn the revenues. This method also helps because it reports all the assets that were earned are reported and all the liabilities that were incurred are reported†. (Averkamp, 2004).

Theories: Criminology and Capable Guardians

Individual Theories Maria Silva CJS/240 Farrell Binder 02/16/2013 There are several theories that influence adolescents are motivated to commit crimes, while other adolescents in similar situations are not. The theories that consist of adolescents committing crimes are based on the routine activities theory, general deterrence theory, specific deterrence theory, biochemical theory, neurological theory, genetic theory, psychodynamic theory, behavioral theory, and cognitive theory.I will talk about the routine activities theory and the general deterrence theory and focus on the bad issues in which adolescents choose to commit a crime. The routine activities theory consist of three variables; â€Å"the availability of suitable targets, the absence of capable guardians, and the presence of motivated offenders. † (Juvenile Delinquency: The Core, 2005) First, the suitable targets; homes that seem very wealthy are more easily to be the crime target. Wealthy homes can contain valuable things such as, jewelry, safe box with cash, cameras, DVD’s, and anything worth value for the offender to make quick money.It is stated that many delinquents do not like to travel to commit their crimes they look around their surroundings, and speak to other children about what they have inside their homes. This is fairly easy for delinquents to commit crimes, and engage other to join in on the crime. They look for unlock homes, expensive cars and valuables worth stealing. Second, the lack of capable parents, in which adolescents feels that if they commit a crime they will unlikely to get caught. Since they believe that their crime will not be caught by a police officer, neighbors, parents, relatives, and homeowners, they will continue to commit crimes.Adolescents or delinquents look for specific safe places to commit their crimes and go undetected from certain types of guardians. Adolescents look around and see where there’s no movement around neighborhoods, where ho mes are left unattended and these become the easy targets for the offenders. In certain neighborhoods, where society is highly, there is more monitoring from guardians such as patrolling of officers, friends, family, and neighbors are less likely to be the target of their homes, and be burglarized, and broken into. Other types of capable guardians are video cameras, and alarm systems and help capture these offenders.Third, variable for routine activities theory would be motivated offender, in which adolescents are more highly motivated to commit a crime. They consist of mostly teenage boys, and unemployment. Motivated offenders select their targets based upon on the value, visibility and accessibility. Motivated offenders may choose not to break-in an unoccupied home, because the presence of a suitable target, because he feels that a guardian, such as a neighbor may spot him, captures him, or phone an officer. Another theory that is motivated in adolescents for them to commit a crim e would be general deterrence theory.General deterrence; â€Å"concept holds that the choice to commit delinquent’s acts can be controlled by the threat of punishment. † (Juvenile Delinquency: The Core, 2005). Offenders will fear of committing crimes, if they know how severe the punishment may be, if they commit the crimes. General deterrence focusses on the prevention of crime and does not focus on the offender, but the offender receives punishment in the public eye or media in order to deter other citizens to commit crimes. As well, that general deterrence theory tries to reduce the probability of committing crimes in the general population. General deterrence results from the perception of the public that laws are enforced and that there is a risk of detection and punishment when laws are violated. † (www. sociologyindex. com) All these theories have a huge effect, routine activities theory and general deterrence theory is more important for adolescents to be aware of. For instance, general deterrence theory is effective for the public, because it shows the punishment of an offender may be and at times it can be severe, helping others not to commit the same crime or any other form of crimes.Routine activities theory are helpful, but needs more of it, for example, more patrolling officers, neighborhood watch committees, more camera surveillance, and more activates or programs for adolescents. Having these types of surveillance, might help reduce crime, because offenders would see that they are watched constantly, and might be afraid to be caught. References: Juvenile Delinquency: The Core, 2005 www. sociologyindex. com

Changing trends in employment Essay Example | Topics and Well Written Essays - 2750 words

Changing trends in employment - Essay Example The increased flexibilization process and deregulation of the labour market from both high and low income countries have, over the years, presented new challenges, especially with the intensification of the market competition in search for decreased production costs. The liberalization of the trade schemes plays a key role in reinforcing the competitive pressures of the global markets. As a result, such developments result in profound changes in technological, production, innovation, employment conditions, and the structures of firms (Alvesson 2001, p. 863). By 1980s, the economic restructuring was enhanced through the decentralization of the production. The institutional changes at the micro level ranged from outsourcing and downsizing to changes in the skill requirement, transformations and work organizations towards the workforce composition. The liberalization of trade has also played a key role in changing the requirements in skills and employment due to the dynamics and the relative wages (Scarborough 1999, p. 8). This shifts the labour intensive production processes to the low-wage countries. These transformations impact differently to both men and women, and the variation is dependent on several factors. The feminization of the labour force continues at both domestic and international levels. This has led to increased participation of women labour force as well as deterioration of the working conditions in jobs previously dominated by males (Balakrishnan & Huang 2000, p. 43-7). Changes in employment have profoundly affected the productive processes and have transformed modes and functions for most firms. This has, in turn, affected the labour relations and employment conditions. The structures in labour markets have been reorganized and destabilized. The changing production landscape at micro-level has increased job opportunities as well as generation of new employment positions. The changes in the micro level of

Information strategy Coursework Example | Topics and Well Written Essays - 1250 words

Information strategy - Coursework Example They may be reluctant to the concept and benefits of consultation and communication. In contrast/consultation and information is likely to be effective in workplaces where the customs is based on an open administration style. Employment relationship behaviours history in the organization can also act as an enabler or an inhibitor to effective consultation and information. Organizations with a history with adversarial relations and those where there has been no tradition of employee participation experience the greatest barriers to shifting to a culture of employee participation. Where there are established relationships through trade unions and partnership working employees may be more open to the opportunities accessible by the directive to review consultation planning. Creating a mixed constituency committees, for example, combining trade union and non union employee’s legislative body may pose serious challenges in the information sharing practices. Practical challenges may come arise from an imbalance of legal rights, expertise, and support between the two groups. Detailed factors must be taken into deliberation when introducing planning tailored to geographically dispersed organizations and those in small organizations. The consultation and information needs to be the same in these organizations whether in large or single site organization. The challenges in a smaller organization revolve around the need to achieve the accurate balance among formality and informality in communication. Question 2 Successful enterprises are built on change; businesses operate in a dynamic environment where the response to changing markets may of benefit to evaluate in hours and days instead of months and years. So responsiveness and adaptability will be of great success. Agent based process administration systems combine the latest distributed computing technology with agent based techniques by providing an intelligent conservatory and alternative to workflow administ ration systems. The advantages associated with agent based process management include, intelligent decision making where management strategy and policy can be represented with a variety of perspectives. Explicit resource management represents the limitation and the value of resources to manage and support the business activities. Anticipation in this process plans the task and schedule available resource anticipation in the business management. APMS react to changing circumstances and have the capacity to generate alternative execution pathways in reacting to specific exceptions. APMS can distribute over multiple platforms across the organization activities using the latest computing technology which is full of open across the machines and operating systems. APMS presents an alternative technology to working flow systems. The major one they offer an alternative vision of how organizations can be planned and managed. The method takes the service oriented view of business procedure ma nagement, where coordinating and resourcing of actions to support an edge to edge business process by relating consultation and collaboration between customers and source agents. Question 3 Workflow management systems have centralized workflow engine unlike APMS which consist of independent systems that represents the respective concerns of various organization units involved the

Land Law Essay Example | Topics and Well Written Essays - 2500 words - 3

Land Law - Essay Example e above it is necessary to discuss the difference between joint tenancies and tenancies in common in order to determine whether property can be transferred to another by a will. It is also necessary to examine the way in which registration can occur with regard to ownership of the property in order to determine whether all five friends would be entitled to be entered on the property register. There also needs to be a discussion in relation to the fact that Ben is only 17 when the property has been bought, as well as a discussion in relation to the differing amounts invested by each in the property. There are two forms of co-ownership of property, which are joint tenancies1 and tenancies in common2. A joint tenancy is a collective ownership of that property. When a joint ownership is created there is unity of ownership amongst the parties3. As a result of this unity of ownership the sale or disposal of the property has to be done collectively. The Council of Mortgage Lenders allows up to four persons to be entered onto the title deeds of the property, although other persons can contribute towards the purchase price of the property. Persons not entitled to be entered onto the register will acquire a beneficial interest in the property only, although, it might be possible for them to be included on the register at a later date, if one of the four named persons either sells their share of the property or dies. Joint tenancy agreements create the right of survivorship4. Under a joint tenancy all persons have an equal share in the property. When one of the joint tenants dies, their share of the property will be divided amongst the surviving tenants. Joint tenants cannot sell their share of property to anyone other than one of the joint tenants, and they cannot transfer their share in a will. Joint tenancies are classed as unseverable5. None of the other tenants can force one of the parties to sell their share of the property and any decision to sell must be a