The Advancement Of The Internet - 888 Words

The advancement of the internet brought with it various other new programs, but social media networks topped the list with regard to terrorist organization recruitment tactics. The increase of social network sites and the lack of boundaries has allowed groups to post any information in an unrestricted forum. The vast reach of the numerous social media networks has revolutionized terrorist organization recruiting techniques by providing them with unlimited access to the global population. The eruption of technological advances has given several organizations a way to reinforce ideas, provide a sense of fitting in, build communication ties, and motivate support to those with little to no technical training (Torres-Soriano, 2013). In the beginning there was not as much access by users and organizations used social media networks to mainly disseminate policy (Torres-Soriano, 2013). Some of the most widely visited and reviewed social media sites are Facebook, YouTube, and Twitter, which provide access all around the world in various languages (Secara, 2015). By inspiring potential HVEs, terrorist organizations can gain support by providing a larger crowd of people to recruit from (Faria and Daniel, 2005). Homegrown Violent Extremists can be of any ethnicity, culture, or race, typically those of western culture who participate or plan to participate in ideologically-motivated extremist activities to promote specific objectives. These HVEs or potential HVE’s are looking forShow MoreRelatedThe Internet Has Changed The World Of Economic Advancement1433 Words   |  6 Pagescommunicates. The internet has become an integral part of America’s economic, political, and social life,† (Bill Clinton ). {2}In fact, the internet has affected nearly every aspect of our lives in ways that we will never fully realize. Obtaining an education has never been easier. {5}Through social medial , we are able to connect not just with our friends, but with the world.{4 }Flourishing greatly, online commercialism is a window to a world of economic advancement. {5 }With the internet at our disposalRead MoreOur Great Influential Advancement is the Internet Essay638 Words   |  3 Pagesinflu ential advancement of the past 100 years would be the internet. The internet single handedly changed the daily life of how people, businesses, and organizations interact on a global scale. Our economy has been greatly impacted by this invention, but it is difficult to quantitatively measure the impact due to its vastness. The internet comes with pros and cons, and in the following paragraphs I will present how we, as a society, have been affected by this invention. The internet has impactedRead MoreTechnological Advancements Have Increased Number Of Internet Enabled Devices1504 Words   |  7 PagesRecent technological advancements have resulted in an increased number of Internet-enabled devices, such as tablets and smartphones that can connect to corporate systems.These systems may also be running anywhere, including a public software-as-a-service (SaaS) cloud, a private cloud, or a hybrid cloud. Internet infrastructure services are also being targeted by hackers who want to take advantage of the reputation, bandwidth, and high uptime and availability.(Belding, 2014) Organizations face someRead MoreEducation and Students1205 Words   |  5 PagesWith advancements in technology, some students have chosen to complete their schoolwork through the Internet, rather than in traditional classrooms. Those who support a traditional classroom approach to learning argue that it provides more of an opportunity for students to interact with the teacher and other students. Those who feel that learning over the Internet is better argue that it allows students to learn anytime and anywhere they choose. Do you feel education is better provided in traditionalRead MoreTechnological Advancement And Its Impact On Technology975 Words   |  4 PagesChoose one area of technological advancement and the impact it is having on moving us toward a more globalized system. I believe that the area of technological advancement that have the most impact on moving us towards a global world are advancements in telecommunications. No matter what other technology advances we make, without the ability to communicate in real time instantly, we could not share technological advancements with other countries and people in other places to harness our collaborativeRead MoreTechnological Advancements Around The World Have Developed1609 Words   |  7 PagesTechnological advancements around the world have developed a unique platform for exclusive application technology as a critical tool useful in the definition of social as well as economic advancements. The extent to which different people can access the technological advancements is significant to the definition of how challenging it is for people to access the same technological advancements, hence the creation of a digital divide. The digital divide can be defined as the state of social inequalityRead MoreEssay on The Internet1096 Words   |  5 Pagesmight well remember it less as the time man walked on the moon and more as the time when the Internet was born. The Advancement Research Projects Agency Network, known as the ARPANET, was developed in the 1960s by the U.S. Department of Defense. This was the worlds first operational informational sharing network, and the predecessor of what we now call the Internet. Although the creation of the Internet was primarily to allow the sharing of resources, its true popularity came in the ability toRead MoreTechnology and Social Changes1225 Words   |  5 Pagesand the radio are examples of technological advances. These advancements have helped revolutionize the way people interact, meet, and conduct business. The increase of technology provides an influx of storage and retrieval, and in return it opens up the channels for knowledge and information. This then leads to better technological advances. All these changes then create concern as to how society will learn to deal with the advancements in technology. Computer technology allows the offices to connectRead MoreHow Technology Has Made It Easier For Students?1269 Words   |  6 Pagesand develop the power to reason or judge. This is evident in the way technology has made it easier for students to cheat, in how the internet provides wrong learning opportunities and in the way students respond to learning while being engaged with technology. Consider the idea that technology has made it easier for students to cheat due to technological advancements. In Rachel Ellaway’s article eMedical Teacher, enumeration is used to list the effects of digital cheating. For instance, â€Å"three aspectsRead MoreEvolution of Mass Communications Essay examples1151 Words   |  5 Pagesof the Internet. Although the impact has been large, the Internet was certainly not the first to revolutionize communications. When many cities started to arise and become industrial-based, there became a need for more technological advancements. When there was one change in the way of living, a domino effect occurred and many more advancements and developments took place. The mass communications of writing, printing, mass media and entertainment have all influenced how we use the Internet and new

Journey Finding Nemo Free Essays

â€Å"Finding Nemo† highlights the adventures of a clownfish named Nemo, as he unexpectedly gets captured at the Drop Off and sent to Sydney. His dad, Marlin, and his friend, Dory, go in search of Nemo encountering many dangers of the ocean. While they continue finding him, Nemo meets new friends at a fish tank of a dentist clinic in which help him escape. We will write a custom essay sample on Journey: Finding Nemo or any similar topic only for you Order Now Towards the end, Marlin finds Nemo and together they go back to their home at the anemone. The film, â€Å"Finding Nemo†, is about the journey as Nemo travel from the familiar to the unfamiliar and the adventures that are encountered as Marlin searches for Nemo. For instance, Nemo arrives at his first day of school where he travels away from the anemone in which he lives to a new place. It is a thrilling experience which is suggested through the playful background music. Nemo’s facial expression also shows his admiration and amazement to the many colourful creatures of the sea which he has not seen before. He unpredictably gets caught in the hands of a diver due to his disobedience acts against his dad. He is taken to a fish tank where weeds and stones are artificial, space is greatly confined compared to that of the ocean and those that live in the tank including Gill, Peach, Bubbles, Jacques, Deb, Bloat and Gurgle, are the strangers in which become Nemo’s friends. The audience knows that the unfamiliar can be frightening as Nemo repeatedly says â€Å"Where’s my daddy? after his capture from the diver. Marlin on the other hand experiences the great dangers of the ocean which he has never thought of encountering as he warns Nemo that â€Å"the ocean is not safe. † His traumatic past through his loss of his wife and many clownfish babies makes him afraid of stepping out of his anemone; however, Nemo becomes the motivation for him to explore further abroad the sea. He swims to an isolated part of the sea where he meets the three sharks, Bruce, Anchor and Chum, and then for the first time travels across a large group of jelly fish and meets sea turtles of Sydney. Nemo’s and Marlin’s journey to the unfamiliar has led them to step out of their comfort zone and further explore the world that exists away from their home. It is very different to what they are used to, therefore leading them to adapt and become a well-informed individual they evolved into by the end of the film. How to cite Journey: Finding Nemo, Papers

Case Study Auditing and Assurance †Free Sample Solution

Questions: Case Study 1: As a result of work undertaken during the planning stage and audit evidence collected for the tests of controls stages of the audit, Robert Smith has determined that there is a low risk of material misstatement (low inherent and control risk) for the following account balances: Wages and salaries Electricity Repairs and maintenance Due to the expected reliability of these controls, Robert has undertaken extensive testing of the controls regarding these account balances, and has concluded that the controls are reliable. Required: Identify one substantive audit procedure for each of the account balances above that will provide sufficient appropriate audit evidence regarding the accuracy of that account balance. Case Study 2: You are reviewing your audit assistants work for Orange Pty Ltd for the year ended 30 June 2015, and note the following matters: Your audit assistant undertook a test of controls for 50 sales transactions. This test resulted in three errors. When planning the test, a tolerable error of 5 per cent had been established. The audit assistants working papers noted that none of the errors found were materials, either individually or in aggregate, and she therefore concluded that the controls were reliable. Your audit assistants working papers on the accounts payable testing contain the following notes and conclusion: In order to test accounts payable, I selected all balances over $100,000 and vouched these to supporting invoices. The sample selected comprised $2,565,650 of total accounts payable of $5,168,000. One invoice for $102,500 had been incorrectly recorded on the accounts payable listing, as the goods were not actually received until after year end. Given the error relates to only 4% of accounts payable tested, which would be a total error of $206,702 of the overall accounts payable balance, it is not material as this is less than the materiality level set for this audit and, therefore, no further work has been performed. I am satisfied that the accounts payable balance of Orange is fairly stated. Required: Comment on the appropriateness of your audit assistants conclusions in each of the above situations. Answers: Case Study 1 Substantive audit procedures for wages and salaries Robert had undertaken accrued wages as well as salary account at the end of accounting period. Most of the audit works on wage system performs at the time of interim period for substantive audit procedures (Whittington 2011). It confirms payroll costs as well as wages accruals as a final part of audits. Interim audit work on wages depends upon normal stages of recording, testing internal controls as well as evaluating for the same. It is advisable in using computer as an audit tool for testing data as well as audit software. It employs at interim period as well as final audit of wages. Testing data consists of data submission by an auditor for application controls like data validation checks. It uses valid as well as invalid transactions for checking operational control at the same time. It tests for ensuring accuracy levels as well as completeness of balances in respect with wages costs and payroll deductions. It enables observing clocking procedures as well as supervision levels in selected payroll agreed hours (Reding 2011). Wages and salaries needs to be audited as per the given rules as well as substantive audit procedures as far as possible. Auditors require proper evaluation in implementation of audit software for conducting audit report at the end of the financial year. Substantive audit procedures for electricity Robert needs to evaluate business in accordance with auditing procedures for assisting financial health of organization. Electricity is one of the expenses that are borne by companies and industries. Companies have different types of internal controls in case of expenses like electricity (Pflugarth 2011). Some invoices include certain signature levels as well as written contract requirements. It requires reasonableness check on ordinary variable expenses like electricity. Having bill from two electric companies taken from one location and causes in case of audit flag. It should have one electricity supplier for the same. Electricity should be received and paid on timely manner. Auditors require selection of random invoices for electricity bill. It needs proper original documentation in against paid amount as well as finding mistakes at the same time (Louwers 2011). Substantive audit procedures for repairs and maintenance Robert needs classify asset because it will; help in recording of fixed assets in correct form. It classifies as capital assets. It ensures capitalization of recording of major part of fixed assets. For instance, repair and maintenance costs treated as expenses as well as significant amount spent for asset improvement at the same time (Leung 2011). It ensures capitalization of additional asset values in an overall manner. Auditors requires in examining selected repair and maintenance work for supporting essential transactions for determination of capitalization of repair costs. Audit procedures for repairs and maintenance include presentation as well as disclosure in the financial statements. It requires testing details in account balances uses by auditor professional in the near future. Professional judgment determines in scrutinizing balanced accounts in case of repairs as well as maintenance in the most appropriate way. Variation as well as allocation ensures examining invoices fo r future analysis purpose (Hooks 2011). Case Study 2 (1). On reviewing Orange Pty Ltd, it is noticed that occurs three potential sampling errors on 50 sales transactions. On planning test, it got around 5 percent tolerable errors that need consideration as far as possible. Audit risk includes uncertainties for sampling attributes for factors at the end of financial year (Hall and Hall 2011). It includes aspects from audit risk like sampling risk as well as non-sampling risk. It provides reliable information from the internal control of audit transaction in Orange Pty Limited. It accepts uncertainty caused from cost and time requirements for future analysis purpose. It examines data as well as adverse consequences in possible erroneous conclusion from data sampling techniques. Sample evaluation relates with likelihood from existing monetary misstatements as well as deviations in and from prescribed controls on proportionate terms. It selects non-statistical analysis for statistical sampling that affects auditors decision-making process (Aren s 2011). (2). Part A After evaluating Orange Pty Ltd annual report, it tests for account payable options as selection of balances $100000 and vouched for supporting invoices. Sampling requires testing accounts payable for current liabilities for Orange Pty Limited. It ensures acquisition of goods for resale by the manufacturer (Whittington 2011). Accounts payable refers as obligations for credit transactions at the same time. It reports gross method as well as net method in purchase assertions in case of cost of goods sold. It requires reconciliation of accounts payable ledger in accordance with control account for future analysis purpose. It ensures purchase cut offs in determination of purchased goods for analytical procedures. It involves cash disbursements in recording payables in the most appropriate way. In case of audit report, auditors need to calculate receivable reports at the same time. Sampling selected consists of $2565650 that totals amounting to accounts payable as $5168000. Invoices compr ises for $102500 as it is incorrectly recorded. It ensures accounts payable in listing of goods in way of account payable options as mentioned in the balance sheet of Orange Pty Ltd. Auditors need to review at the trend lines of sales as well as accounts payable as unusual trends. It helps in measuring accounts payable collection period at the same time (Hall and Hall 2011). Part B In this particular question, errors records only 4% of accounts payable tests for total error of $206702. It sets for materiality set in audit process in final audit process in the most appropriate way. On critical analysis, it is stated that Orange Pty Ltd is fairly stated in the financial statements in the near future. Auditors requires in reviewing selected credit memos as per audit report analysis. It assess entries related to provision for bad as well as doubtful debts as per the business environment (Whittington 2011). Auditors need to evaluate in the account payable attributes as per the test errors for future analysis purpose. It records auditing errors for setting solutions for the material misstatement in the financial statement analysis of Orange Pty Limited. Reference List Arens, A. (2011).Auditing, assurance services ethics in Australia. Frenchs Forest, N.S.W.: Pearson Australia. Hall, J. and Hall, J. (2011).Information technology auditing and assurance. Mason, Ohio: Thomson/South-Western. Hooks, K. (2011).Auditing and assurance services. Hoboken, NJ: Wiley. Leung, P. (2011).Modern auditing assurance services. Milton, Qld.: John Wiley. Louwers, T. (2011).Auditing assurance services. New York: McGraw-Hill Irwin. Pflugarth, G. (2011).Auditing, assurance and ethics handbook 2011. [Frenchs Forest, N. S. W.]: Pearson Australia. Reding, K. (2011).Internal auditing. Altomonte Springs, Fla. Whittington, O. (2011).Principles of auditing other assurance services. [Place of publication not identified]: Irwin Mcgraw-Hill.

The entire story Essay Example For Students

The entire story Essay Whilst eating the lamb as requested my Mary Maloney, the four policemen (within the house) discuss amongst themselves of the different possibilities of the type of weapon used and its possible whereabouts. One of the policemen concedes that its on the premises itself and ironically probably right under our very noses whilst Mary Maloney starts giggling in the other room.  Like Lamb to the Slaughter, The Adventure of the Speckled Band subverts the conventions of the genre from the very beginning itself, the title. When one hears the Adventure of the Speckled Band theyre most likely to be intrigued and quite keen to read the story. We will write a custom essay on The entire story specifically for you for only $16.38 $13.9/page Order now Another way in which Doyle subverts the conventions of the genre is by using a fictional narrators (Holmes assistant-Watson) point of view. This is evident as Doyle has presented the complete story as a memoir of Dr. Watson. It can also be seen that the first paragraph isnt directly related to the events that took place and is more of an introduction to a recollection of Dr. Watson. The narrator also states that he made a promise to a lady not to reveal these matters and has only done so due to her untimely death; intriguing the readers and making the story sound more realistic. The fact that the accounts are supposed to be secretive further creates intrigue within the readers as it is human nature to be attracted to secretive information. Doyle uses Dr. Watsons point of view to make it sound less fictional and more autobiographic; giving the readers a sense of authenticity and make the entire story more realistic.  Using Watsons point of view also helps the main character (Holmes) look far more superior and intellectual than he is, as Watson himself is portrayed to be in awe of Holmes, this is shown when Watson admits that I had no keener pleasure that in following Holmes in his professional investigations. Once Holmes and Watson had arrived in the living room to meet Miss Stoner, the dialogue between Holmes and Miss Stoner and Watsons descriptions were used to help build suspense e.g. when Holmes points out precise details about Miss Stoners journey to Waterloo, she is startled. The readers were probably expected by Doyle to have a similar reaction.  After the brief disclosure of her families past, she then explains the sudden change in character that took place within Dr. Roylott; regularly holding feuds with the local residents and neighbours.  Despite the extensive statement by Miss Stoner regarding her family, the readers havent yet read about the reason behind Miss Stoners concerns; building tension in the readers mind ever so slightly. The tension starts to increase when Miss Stoner describes the follow up to her sister Julias death. The tension builds from the point where Miss Stoner admits of having A vague feeling of impending misfortune, this is also breaking conventions Miss Stoner, a major character in the story is shown to have had an instinctive impression that something bad was going to take place. The tension alleviates slightly once Holmes starts asking a couple of questions regarding the deaths and Miss Stoner hesitates to confirm that she heard the whistle and the metallic clang. The tension builds up when Miss Stoner concludes that her sister certainly was alone due to the lack of any marks of violence upon her sister Julia. Leading the readers to think that an unconventional and mysterious form of crime has took place.  Tensions build up once again when Miss Stoner calls her late sisters bedroom a chamber, suggesting to the readers that Miss Stoner herself felt uncomfortable about being in that room and thought of it as a prison cell. After Miss Stoner had left Holmes office, the tension turns down whilst Holmes and Watson discuss the different possibilities, until suddenly, the door was dashed open by Dr. Grimesby Roylott. .uee16744cdc27bc6378de50e750b00645 , .uee16744cdc27bc6378de50e750b00645 .postImageUrl , .uee16744cdc27bc6378de50e750b00645 .centered-text-area { min-height: 80px; position: relative; } .uee16744cdc27bc6378de50e750b00645 , .uee16744cdc27bc6378de50e750b00645:hover , .uee16744cdc27bc6378de50e750b00645:visited , .uee16744cdc27bc6378de50e750b00645:active { border:0!important; } .uee16744cdc27bc6378de50e750b00645 .clearfix:after { content: ""; display: table; clear: both; } .uee16744cdc27bc6378de50e750b00645 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .uee16744cdc27bc6378de50e750b00645:active , .uee16744cdc27bc6378de50e750b00645:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .uee16744cdc27bc6378de50e750b00645 .centered-text-area { width: 100%; position: relative ; } .uee16744cdc27bc6378de50e750b00645 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .uee16744cdc27bc6378de50e750b00645 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .uee16744cdc27bc6378de50e750b00645 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .uee16744cdc27bc6378de50e750b00645:hover .ctaButton { background-color: #34495E!important; } .uee16744cdc27bc6378de50e750b00645 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .uee16744cdc27bc6378de50e750b00645 .uee16744cdc27bc6378de50e750b00645-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .uee16744cdc27bc6378de50e750b00645:after { content: ""; display: block; clear: both; } READ: Oedipus Rex EssayA war of words erupts between Holmes and Roylott. However Holmes is hesitant to involve himself in a verbal confrontation thus decides to shrug off any comments made by Dr. Roylott with humour.  After sometime the most anticipated and tense part of the story begins when Holmes and Watson enter Stoke Moran through Late Julia Stoners bedroom.  The tension dies down when the readers discover that there were no whistling noises of any sort for at least 3 hours after midnight, until suddenly Watson hears the whistle, which he describes to be a gentle, soothing sound. Tensions suddenly shoot up as Watson states that Holmes used his cane to lash savagely at the bell pull. A short hiatus in tension occurs amidst all the tensions when suddenly both Holmes and Watson hear an immensely loud shriek. Holmes is quoted to have said Its all over.  Tension is finally built up when Holmes and Watson make their way to Dr. Roylotts bedroom with Watson carrying an Eleys No.2. They are shocked to see the two perpetrators of the murder, one alive, one dead. Here also Doyle breaks the conventions as the murderer dies by his own weapon.

Image Of Man Essays - Gender, Masculinity, Biology, Free Essays

Image Of Man Essays - Gender, Masculinity, Biology, Free Essays Image Of Man The Image of Man Essay Throughout the past few centuries, man has been notorious for his masculinity. However, masculinity was labeled by the changing societies and ideals, creating different aspects of manliness. By objectifying human nature, people began to stereotype. By stereotyping, it mad it easier for people to understand by perceiving and to a great extent passing judgment on another human being. The stereotype of masculinity seemed to arise somewhere in between the second half of the eighteenth century and the nineteenth century. With the beginning of the modern age, Europe started to enter a more visually oriented age, therefore making the formation of the male body become key. Europeans began to homogenize, or look at man as a type, rather than an individual. They believed that there was no reason for individual change and wanted the men to accept measure up to the ideal of masculinity. Masculinity was strengthened due to the positive stereotyping, however for those that did not conform to this label or fit in with the ideal, were negatively stereotyped. Nationalism and masculinity went hand in hand. As masculinity became adopted as part of the national stereotype, they initiated their growth together. Mass stereotyping was bourgeois orientated. At first, mass stereotyping was for intended purposes of being and open ended process, yet it eventually turned into a distinct a mbition. Women, during this period, projected chastity and innocence. While men and women were thought of as not equal, they were thought as to compliment each other. Racism, especially towards the Jewish and Africans, became clear and developed from the judgment of masculinity. Because the ideal had already been set and put into play, the counter parts, Jewish, Africans, or others, had no room to advance. The ideal of masculinity started to sway as the Enlightenment approached and came. The model was of humanistic spirit, rather than the anatomy and returned to the ideas of socialist men such as Max Alder. However, this shot at changing the normative male stereotype failed. The bourgeois was the main component in shaping the modern man. But, there were previous contributing factors to the molding of this masculine stereotype. Medieval ideals lasted well into modern times. Chivalry was a main factor and to be called a coward was a great insult. The duel had been a ritual since the sixteenth century and was fought for male honor. Aristocratic ideals consisted of the linkage of blood, or lineage and descent. Theses ideals were primarily based on warrior caste. The ingredients in forming this modern masculinity, was through the combination and adjustment of both aristocratic and bourgeois classes. This merging of classes started to reflect in the way society saw man. By the end of the eighteenth century the standard of masculinity was measured by looks, appearance, and behavior. In Germany, the bourgeois male code of honor was used as a status symbol. Jewish people were gradually excluded. And the elite fraternities would have male dueling. In France, the d uel was not to kill, but to display manly qualities. By the end of the nineteenth century, the emphasis was basically pointed at justice and equality. If a man defends his honor for sole purpose of appearing honorable, the honor code ceases to fulfill its original function and becomes a travesty. (20, endnote #21) This justice and equality began when the duelers would handshake at the end of a match. Duels went on and became a form of exercise and meant not only moral toughness, but physical as well. The duels along with other undertakings started to set a standard, which becomes known as the new masculine modern stereotype. The masculine ideal valued the physical, moral, and visual perceptions, and became a symbol of society and nation. The Enlightenment focused on the joining of the body and spirit. Johann Kaspar Lavaters theory comprised of seeing people through their physical, such as their color, nose, eyes, and bodily structure. He stated that the Greeks were more beautiful th an the people of today and if a man could base his beauty on the Greeks then they would attain moral posture. This general principle was derived from actual concrete evidence such as engravings and statues. With the turn

Prehistoric Life During the Devonian Period

Prehistoric Life During the Devonian Period From a human perspective, the Devonian period was a crucial time for the evolution of vertebrate life: this was the period in geological history when the first tetrapods climbed out of the primordial seas and began to colonize dry land. The Devonian occupied the middle part of the Paleozoic Era (542-250 million years ago), preceded by the Cambrian, Ordovician and Silurian periods and followed by the Carboniferous and Permian periods. Climate and Geography The global climate during the Devonian period was surprisingly mild, with average ocean temperatures of only 80 to 85 degrees Fahrenheit (compared to as high as 120 degrees during the preceding Ordovician and Silurian periods). The North and South Poles were only marginally cooler than the areas closer to the equator, and there were no ice caps; the only glaciers were to be found atop high mountain ranges. The smallish continents of Laurentia and Baltica gradually merged to form Euramerica, while the giant Gondwana (which was destined to break apart millions of years later into Africa, South America, Antarctica, and Australia) continued its slow southward drift. Terrestrial Life Vertebrates. It was during the Devonian period that the archetypal evolutionary event in the history of life  took place: the adaptation of lobe-finned fish to life on dry land. The two best candidates for the earliest tetrapods (four-footed vertebrates) are Acanthostega and Ichthyostega, which themselves evolved from earlier, exclusively marine vertebrates like Tiktaalik and Panderichthys. Surprisingly, many of these early tetrapods possessed seven or eight digits on each of their feet, meaning they represented dead ends in evolution since all terrestrial vertebrates on earth today employ the five-finger, five-toe body plan. Invertebrates. Although tetrapods were certainly the biggest news of the Devonian period, they werent the only animals that colonized  dry land. There was also a wide array of small arthropods, worms, flightless insects and other pesky invertebrates, which took advantage of the complex terrestrial plant ecosystems that started to develop at this time to gradually spread inland (though still not too far away from bodies of water). During this time, though, the vast bulk of life on earth lived deep in the water. Marine Life The Devonian period marked both the apex and the extinction of the placoderms, prehistoric fish characterized by their tough armor plating (some placoderms, such as the enormous Dunkleosteus, attained weights of three or four tons). As noted above, the Devonian also teemed with lobe-finned fish, from which the first tetrapods evolved, as well as relatively new ray-finned fish, the most populous family of fish on earth today. Relatively small sharkssuch as the bizarrely ornamented Stethacanthus and the weirdly scaleless Cladoselachewere an increasingly common sight in the Devonian seas. Invertebrates like sponges and corals continued to flourish, but the ranks of the trilobites were thinned out, and only the giant eurypterids (invertebrate sea scorpions) successfully competed with vertebrate sharks for prey. Plant Life It was during the Devonian period that the temperate regions of the earths evolving continents first became truly green. The Devonian witnessed the first significant jungles and forests, the spread of which was aided by the evolutionary competition among plants to gather as much sunlight as possible (in a dense forest canopy, a tall tree has a significant advantage in harvesting energy over a tiny shrub). The trees of the late Devonian period were the first to evolve rudimentary bark (to support their weight and protect their trunks), as well as robust internal water-conduction mechanisms that helped to counteract the force of gravity. The End-Devonian Extinction The end of the Devonian period ushered in the second great extinction of prehistoric life on earth, the first being the mass extinction event at the end of the Ordovician period. Not all animal groups were affected equally by the End-Devonian Extinction: reef-dwelling placoderms and trilobites were especially vulnerable, but deep-sea organisms escaped relatively unscathed. The evidence is sketchy, but many paleontologists believe that the Devonian extinction was caused by multiple meteor impacts, debris from which may have poisoned the surfaces of lakes, oceans, and rivers.

Unit V AAssessment#3 Oxidative Stress Essay Example | Topics and Well Written Essays - 250 words

Unit V AAssessment#3 Oxidative Stress - Essay Example In order to eavaluate thr ability of particulate air pollution to promote oxidative stress, six adult pathogen free Sprague-Dawley rats were obtained from Taconic Farms in New York,USA, and fed with conventional laboratory diet and water ad libium.Three of the rats were exposed to filtered air (control group) and the other three were exposed to concentrated ambient particles (CAPs). Throughout the study, all rats were awake and unrestricted. At 1, 3 and 5 hours, two rats: 1 from filtered air and 1 from CAPs , were removed and analysed. The rats that were exposed to CAPs aerosols for 5 hours showed significant oxidative stress. The rats showed significant increase in lung and heart water content (about 5% , p According to Gurgueira, et al., (2002 p.260), the generation of ROS can induce cellular oxidative stress and biological effects,including DNA damage.In most aerobic cells, electron –transport chains are located in mitochondria and the endoplasmic reticulum . The electron –transport chains are the major source of ROS produced in vivo (Gurjar, et al., 2010: p.190). Gurgueira, S. A., Lawrence, J., Coull, B., Murthy, K. G. G., & Gonzà ¡lez-Flecha, B. ( 2002). Rapid increases in the steady-state concentration of reactive oxygen species in the lungs and heart after particulate air pollution inhalation. Environmental Health Perspectives, 110(8),