Case Control Study - 961 Words

Discussion In recent years, it has been suggested that miRNAs act as key regulators of gene expression networks. Like other genes, single nucleotide polymorphism in miRNA genes can affects their function at different levels, such as miRNA transcription, maturation and target specificity. Our study is the first report of mir 23a, mir155 and mir 196a2 polymorphism in the iranian MS patients. In this case control study we examined the impact of functional mir 155 rs767649, mir196a2 rs11614913 and miR-23a rs3745453 polymorphism on MS risk in a sample of Isfahan population. We found that miR-23a rs3745453 CT variant seem to increase the risk of MS in this population (OR =2.5). Compared with ridolfi et al. The results did not support an†¦show more content†¦Saumet et al. in 2008 observed that miR-23a~27a~24-2 is directly repressed by the PML-RARA oncogene. also in some study upregulation of miR-23a has been observed in cancers(22). Considerable up-regulation of miR-23a was reported by Meng and Gottardo in human bladder cancer and in malignant cholangiocytes compared to normal tissues. Furthermore, Mi et al. in their study showed that miR-23a was among several other miRNAs that have been differentially expressed between acute myeloid leukemia (AMLs) and acute lymphoblastic leukemia (ALLs). In addition, up-regulation of miR-23a/b along with miR-24 has also been identified in osteoblast cell line (20,21). An exonic MiR-155 with rs767649 (T/A) polymorphism in the upstream region of the pre-miR-155 gene is transcribed from the B-cell integration cluster (BIC) that is located on chromosome 21. It has been suggested that miR155 modulate host antiviral immune response by elevating type I IFN signaling. In some study This miRNA proposed to be involved in diverse biological processes, such as inflammation, differentiation, and immunity. Furthermore, dysregulation of miR-155 has been reported in viral infections and different cancers. Some study reported mir155 highly expressed in activated T and B cells as well as macrophage and dendritic cells(23). Our result suggested that rs767649 TT genotype have potential to act as a risk factor for MS(OR=2.5), also 94 % ofShow MoreRelatedFatty Acid Composition Of Adipose Tissue And Colorectal Cancer : A Case Control Study845 Words   |  4 PagesFatty acid composition of adipose tissue and colorectal cancer: a case-control study Colorectal cancer is considered as the third most common cancers worldwide that usually leads to the death of the patient. Studies have proved that lifestyle factors great influence the development and spread of cancer. Modifying the lifestyle can reduce the risk of getting colorectal cancer by 70%. It is noted that more consumption of red and processed meat increase the risk of developing colorectal cancer. HoweverRead MoreA Study On Sudden Infant Death Syndrome1664 Words   |  7 PagesBackground Information: The study took place in north Europe Scandinavian countries such as Denmark, Norway and Sweden. The local paediatrician from Norway and Sweden and the forensic institution of Denmark invited parents of sudden infant death syndromes (SIDS) to take part in the study. Sudden infant death syndrome is the sudden, unexpected and unexplained death of an apparently healthy baby. There were several aims behind the study. The main aim of the study was to overlook whether smoking wasRead MoreUnderestimated Due With An Inadequate Surveillance System1683 Words   |  7 Pagesthe increase in surveillance and intervention in both cases is the advancement in technology and increase in mobility of modern times and globalization. As a result of this, American economic stimulation in the Caribbean demanded surveillance increases; the possibility of travel by EHF victims/contacts from West Africa caused hysteria in the Western world and stimulated intervention from world and American health care authorities. 2. A case study outline for salmonellosis involves the identificationRead MoreDepression And Dementi Depression1276 Words   |  6 PagesSeveral studies have shown links between depression and dementia. Brommelhoff, Johansson, Fratiglioni, Gatz, McArdle, Pederson state, â€Å"there are three hypotheses that might explain the association† (Jorm, 2001). The first is that depression is a symptom that indicates the onset of dementia, also known as a prodromal feature. The second is that the two are independent illnesses; however, depression causes cognitive deficits, which lead to an earlier onset of dementia. The last argues that depressionRead MoreThe Association Between Low Hdl Blood Levels And Colonic Cancer1648 Words   |  7 PagesDyslipidemia is a pathological alteration of lipid and lipoprotein concentrations in the blood. It is one of the main elements of metabolic syndrome. Epidemiological studies have shown that persons with the metabolic syndrome have an increased r isk of colorectal cancer (CRC). One of the possible mechanisms is that lipids and lipoproteins have been found to be associated with neoplastic processes as well as inflammation, insulin resistance and oxidative stress. On the other side, some of the factorsRead MoreHuman Searches Of Databases Produced A Total Of 704 References And Abstract Records After Removal Of Duplicates.we Accessed 18967 Words   |  4 Pagespapers for further full text screening to determine eligibility. We found 1 ongoing study (Badlani 2009) and four studies (Hajebrahimi 2011; Lee 2011; Xu 2007; Yamanishi 2004) fulfilled the inclusion criteria. A flow diagram of the process of selecting studies is presented in Figure 1. Included studies    A total of 322 females with VD in four trials were randomly allocated to pharmacological interventions or control groups. In Hajebrahimi 2011, 40 females diagnosed with VD according to AUASS andRead MoreA word related presentation happens throughout the execution of occupation obligations and may put900 Words   |  4 Pagesis a vital device in danger evaluation and in the administration of exercises including treatment of risky substances.[1] There are numerous perilous substances for which there are no formal word related presentation limits. In these cases, danger banding or control banding methods might be utilized to guarantee safe handling.simple representation of presentation danger appraisal and administration progressive system focused around accessible data Word related Introduction Limits (Oels) have beenRead MoreEvidence Based Practice Worksheet On Patient Care1067 Words   |  5 Pagesenteral nutrition therapy. Results of two retrospective studies determined that by the 45th week of enteral nutrition administration, 85% of patients reached remission when compared to only 76% of remission in patients who were receiving an oral route of nutrition intake. However, all of the patients examined did exhibit a decrease in severity of the disease (P0.0001). Additionally, the Children’s Hospital of Philadelphia reported a retrospective study determined that 65% of 23 patients reporting withRead MoreViewing Cute Images Increases Behavioral Carefulness1370 Words   |  6 Pagesthem to use tweezers to remove plastic body parts without touching the sides of the compartments. The game served as an assessment of behavioral carefulness. Participants exposed to cute infant animals displayed greater improvements in fine-motor control from before to after the slide show. Lack of consistent changes in physiological measures ruled out general physiological arousal as an explanation. Results indicated that cuteness not only motivates people to nurture, but also enhances their abilityRead MoreEssay about Its Time To Make Marijuana Legal for Recreational Use 923 Words   |  4 Pa gesharmless to the adult user. Several studies have concluded that even long-term use of marijuana is not associated with an increased cancer risk. This includes cancers of the lungs, prostate, breasts, or cervix among others under current study. A recent population-based case-control study in 2009 even found that light marijuana usage over a 20 year period was associated with a lowered risk of head and neck cancer, and a 5-year-long population-based case control study found that even long-term heavy marijuana

Its Time for Open Adoption Essay - 1087 Words

Its Time for Open Adoption Based on statistics gathered by the United States Department of Health and Human Services Childrens Bureau, approximately 46,000 children found homes through the foster care system last year alone (Cumpston, 8b). It is hard to imagine that there is this unbelievable number of children adopted in just one year, and the process is still different for every family who goes through it. Only after much research, can one conclude that while handling an adoption, a process known as open adoption is the most beneficial for everyone alike. There are essentially two ways to adopt a child; one technique, known as an open adoption and one known as closed. Throughout the first quarter of the century,†¦show more content†¦As a result of the birth parents and the adoptive parents maintaining contact with each other, the adoptee is able to ask questions pertaining to why s/he was put up for adoption and consequently can better understand the events leading to the situation. This helps to wave a portion of the feelings of abandonment, common to many children after an adoption. Otherwise the sense of abandonment will more than likely carry over into the adult life and affect the way that person handles stressful situations (Open Adoption). Additionally, the adoptee will have access to background information readily provided by the birth parents, thus eliminating countless searches by the child when s/he is older. Many adopted children chase after their true identity their whole lives, in turn not finding anything but a few measly pictures or letters (Baran, p 235). In all reality, it makes sense that a mother who knows where her child is going, with whom, and in what kind of environment, will be, at the very least, relieved of a small amount of apprehension. In most cases, prior to the adoption, a legal document will be written up, agreed upon and signed by both sets of parents, therefore describing the extent of contact by the birth mother with the child.Show MoreRelatedAdoption Is A Important For Children994 Words   |  4 Pages Adoption Adoption is a practice that is as old as time. It was spoken of in the Bible and has been proven as a successful way to make sure unwanted children get a home and family. Adoption can be a positive experience for those who cannot have a child and want to provide a loving environment. There are some who feel that people should take responsibility for their actions if they have the child. While I do agree with accountability, sometimes being a parent is realizing when the better option forRead MoreEssay about The Advantages of Closed Adoption Over Open Adoption1092 Words   |  5 Pageswho I am. My whole life is messed up. It’s not my fault. It can’t be fixed,† said a girl adopted into an open adoption (Byrd). An open adoption is a process in which the birth parents and the adoptive parents know each other and are involved in the adopted child’s life. A closed adoption is when there is no contact at all and no identifying information is given between birth and adoptive parents (Byrd). While both are common to today’s society, closed adoptions allow opportunities for the adoptiveRead MoreAdoptees Have The Right Of Original Birth Certificates1086 Words   |  5 Pagesquestions, because of equality issues, and because of the doors it opens to adoptees that have empty holes in their history. First, adoptees have the right to have access to original birth certificates because they have questions. Questions about their health, questions about who they came, who they got their blue eyes from, and other such things. As Melinda Elkins Dawson, one of 200 newborns relocated to other states for adoption in Georgia in the 50’s and 60’s says, â€Å"Every adopted child has questionsRead MoreClosed Adoption : A New Home864 Words   |  4 PagesClosed Adoption About twenty years ago my Uncle Hosea had a son named Javion. He was the first boy out of all the girls my uncle had conceived, which made him very proud. However, due to some underlying circumstances, he was taken away from his mom and put into the system. He was somehow adopted and never seen again, nor has any information been given out to our family to help locate him. He had entered closed adoption, which is an irreversible system where parents give up their rights to know anyRead MoreEssay about Arguments for Open Adoption Records1721 Words   |  7 PagesFor those who are a part of the adoption world one of the most hotly debated issues is whether birth records should be open or closed to adoptees. With this issue comes strong feelings on both sides. In most states adoption records are fully sealed and inaccessible, unless the adoptee petitions the court. In 16 states these records are fully or partially available upon request with no court involvement, and also may depend u pon when you were born. In a few states records are completely prohibitedRead MoreEssay on Why Should Abortion be illegal?659 Words   |  3 Pages Abortion is taking the life of a new human being. Many people would say that it’s not human to kill another person but what makes abortion any different from that? The main reason why many women abort is because they’re too young and are scared of the impact a baby will make in there life, they don’t have enough money to support a child, or their relationship starts failing after finding out they’re pregnant. As a Christian I was taught that abortion is wrong and that only God can determine whoRead MoreOptions Other than Abortion Essay978 Words   |  4 Pagesabortion is one of many solutions to get rid of a baby that is not wanted or it’s not the right time to raise a baby; it is also one of the most controversial issues of our time. Abortion has it’s own effects on people and society mostly i n a bad way. Church and other religious groups are against abortion, while others in our society are supporters. There are some options other than abortion to solve this issue, such as: adoption, teen parenting, and more. â€Å"How many more women will be exploited, injuredRead MoreAdoption and Parent775 Words   |  4 Pagesthousand adoption cases take place each year. Adoption is the practice where the rights of biological parent(s) to the child are transferred to foster parent(s) permanently. Adoption of a child usually would take place at a tender age of the child’s life, so the child wouldn’t know of ever being adopted. Although this depends on if the child’s foster parents reveals to them the information of them being adopted. Usually a biological parent putting their child in foster care or up for adoption is allRead MoreAbortion Persuasive Essay755 Words   |  4 Pagesa chance at life. Adoption is one of these safe solutions. Kristi Burton Brown stat ed â€Å" In the USA, there are approximately two million infertile couples waiting to adopt†¦Ã¢â‚¬  The child that is considered a â€Å"mistake† could be the miracle that a couple has been waiting for. Adoptions can cost an enormous amount of money, however it proves that these families are not in it for the money, instead they are in it because they have waited to hold a baby that they can call theirs. Adoption is full of differentRead MorePersuasive Essay On Adoption1100 Words   |  5 PagesAdoption Adoption is a process whereby a person assumes the parenting of another, usually a child, from that persons biological or legal parent, and in so doing, permanently transfers all rights and responsibilities, from the biological parent or parents. Unlike guardianship adoption effect a permanent change in status and as such requires societal recognition. Adoption is a good process which helps children in different ways. I prefer to handle adoption worldwide and in all societies

Othello Iago Essay Example For Students

Othello Iago Essay Iago has no conscience. He is an angry man and is happy to take down everyone around him to get what he wants: revenge. It is in Act 1, Scene 3, that he devises his evil plan. Here we can see inside Iago’s mind. It is easy to see that his primary motivation is jealousy: jealousy that Othello may have slept with his wife, and jealousy that Othello chose Cassio over him. As he plots his revenge, it is clear Iago respects and cares for no one. (Act 1, Scene 3, 378-381)I hate the Moor,And it is thought abroad that twixt my sheetsH’as done my office. I know not if’t be true,But I, for mere suspicion in that kind,Will do, as if for surety. Iago states here he suspects Othello may have slept with his wife. He is not sure of this, but declares that surety is not necessary. I believe Iago is not so much concerned with his wife being unfaithful, but that he can’t stand the thought that it may have been with Othello. (Act 1, Scene 3, 381-382)He holds me well;The better shall my purpose work on him. This shows how conniving Iago is. He will use the fact that Othello trusts him to get his revenge. (Act 1, Scene 3, 383-385)Cassio’s a proper man. Let me see now;To get his place, and to plume up my willIn double knavery. How? How? Let’s see. Here â€Å"double knavery† means to pull off one stunt and obtain two desired outcomes to get Cassio’s position (which he felt he deserved) and to make himself appear respectful for his ego’s sake. Another benefit of getting Cassio’s position is he can be closer to Othello. When he accomplishes this, he will be able to obtain even more trust from Othello and begin manipulating him to believe that Cassio and Desdemona are having an adulteress relationship:(Act 1, Scene 3, 386-389)After some time, to abuse Othello’s earsThat he is too familiar with his wife. He hath a person and a smooth disposeTo be suspected framed to make women false. Iago knows that Othello is a man of integrity and therefore, believes others to be so until proven differently. Iago has no respect for integrity and consequently, has no respect for Othello. This is obvious in his reference to Othello as an â€Å"ass† which can â€Å"tenderly be led by th’ nose.†(Act 1, Scene 3, 390-393)The Moor is of a free and open natureThat thinks men honest that but seem to be so;And will as tenderly be led by th’ noseAs asses are. One of the frightening things about Iago is that he takes what most of us see as good and uses those traits against them. There are several examples in this soliloquy. One example is when he refers to Cassio being a â€Å"proper† man. Proper means handsome in this context. Being handsome is positive but Iago will use Cassio’s handsomeness to evoke jealousy in Othello. Women are attracted to Cassio. Already amazed Desdemona â€Å"chose him,† a large, black scarred man, not conventionally handsome at all, it will be easy to convince Othello that Desdemona might be attracted to Cassio. Another example is that Iago will use Othello’s trustfulness and integrity. Iago knows Othello already trusts him. Iago will â€Å"play† an honest man who is loyal and loves his general. If this is the case, why would Othello believe for a minute that Iago is not telling him the truth?With this, revenge comes easy for Iago.

Rebecca By Du Maurier Essays - English-language Films,

Rebecca By Du Maurier As Daphne du Maurier finished her novel, she said to herself, "So it was. A finished novel. Title, Rebecca. I wondered if my publisher would think it stupid, overdone. Luckily (for me) he did not. Nor did the readers when it was published." Little did du Maurier know, her novel ended up becoming a great success. Soon after, Alfred Hitchcock made a film version of Rebecca that soon became an even greater success than the novel itself. There are many opinions as to which version is more effective. I believe that the novel was far more effective that the movie version for a number of reasons. One of the reasons that I feel that the original novel Rebecca was more effective than the movie version was that I think the novel held suspense in a better way. While reading the novel, my suspense was able to build up more and more as I read further on. The plot seemed to move slowly, without revealing too much information very quickly. It gave me a chance to think for myself what I thought would happen next, which got my imagination working. When watching the movie, I found that each event happened too quickly, which didn't give me much of a chance to think about what was going on. One example of this is when Rebecca's boat was discovered. In the novel, each event that happened during that time was explained slowly. Much detail was given and as I read on, my suspense was able to build up while I was waiting to find out what had really happened. In the movie, the events during that time went very quickly, and the information was just thrown at you and then it was over. Also, during the movie, the events kept on happening without any pause which didn't give you time to think, let alone gather up the information given. In the novel, one important event would happen, giving more information, and then the plot would slow down a bit, allowing me to gather my thoughts and form and idea of what I thought would happen next. Another reason why I thought the novel was more effective than the movie was that the movie didn't go into as much detail as the novel did. In the novel, every part of the plot was explained into such detail that I could imagine everything almost to the point that I felt I was right there in the story. Each and every character was explained so well that I could actually see them in my mind. One example of this is when du Maurier explained what Mrs. Davners was like. She was described with such an evil sense of passion that it actually sent a chill up my spine and I was able to feel a dark presence about the story every time her name was mentioned. In the movie, the plot moved very quickly and nothing went into much detail. The characters didn't have much significance because nothing was really told about them except from what you learned from the initial plot of the story. The last reason why I believe the novel to be more effective than the movie version of Rebecca is that the novel is able to get my imagination working more effectively. During the novel, things move slowly giving you time to form your own thoughts as to what is happening. The novel also takes more time and hints at things before giving the actual information about the truth to the whole story. This allowed me to use my imagination and add on to what I already knew about the story and then come up with my own idea of what I thought was going to happen. The best example of this is when Maxim was throwing the costume ball. While the protagonist, Mrs. de Winter, was trying to think of a costume, and then Mrs. Davners gave her the idea to use the white gown from the picture of Caroline de Winter, there were little hints that made me realize that there was something that wasn't being told. I thought it to be very unlikely that Mrs. Davners would help Mrs. de Winter, so I came to the conclusion that something bad was going to come of the whole situation. I was able to use my imagination and form my own ending to the situation. While watching the movie, I wasn't given the time or the pauses to allow me

Definition and Examples of the Habitual Present Tense

Definition and Examples of the Habitual Present Tense In English grammar, the habitual present is a verb in the  present tense  used to indicate an action that occurs regularly or repeatedly. It is also known as the present habitual. Typically, the habitual present employs dynamic verbs, not stative verbs, and it may be accompanied by an adverb of frequency such as always, often, or  seldom. Examples and Observations He  runs every morning in  New York. Twice around the reservoir. I know, because I go with him. I dont run, but I go.  (Wil Haygood, Sweet Thunder: The Life and Times of Sugar Ray Robinson. Knopf, 2009)In the movie 50 First Dates, Lucy Whitmore wakes up every day with no memory of the previous day as a result of an automobile accident that has virtually eliminated her short-term memory.His wife buys daily the food for that day in a permanent market of small stores and booths in the plaza in quantities so small as to astound and amaze an American housewife.(May N. Diaz, Tonal: Conservatism, Responsibility and Authority in a Mexican Town. University of California Press, 1966)Joshua Stillman must be old but nobody ever thinks of what his age might be, he is so very much alive. He goes to the city every day and comes back early every afternoon. As he so seldom talks about himself nobody knows exactly what he does except that it has to do with books and small print.(Katharine Reynol ds, Green Valley. Grosset Dunlap, 1919) Adverbs of Frequency with the Habitual Present Present tense is also used with active verbs to describe something that happens routinely or habitually. Like the present tense that is used for general statements of fact, the habitual present tense does not limit routine or habitual activities to a particular time span. Instead, it suggests a timeless quality; that is, the habit or routine that happens regularly also did so in the past and will do so in the future. Hurran uses his truck to carry food and water to his familys tent camps in the desert. When the present tense is used to describe a habitual or routine activity, it may have an adverb of frequency with it. Each Saturday, Hurran drives into town to get food and water supplies. He washes and waxes his truck each week. (Linda Bates, Transitions: An Interactive Reading, Writing, and Grammar Text, 2nd ed. Cambridge University Press, 2005) The Habitual Present and the Present Progressive The habitual present . . . is used with dynamic verbs to encode situations that occur habitually over time, even if the action is not being carried out at the moment of speaking. For instance, referring to the following examples, Tim may not actually be working, nor the leaves falling at the moment of speaking. Nevertheless, the recurrent situation holds as the normal course of things and is appropriately referred to by the present tense. Tim works in an insurance company. Many trees lose their leaves in autumn. Again, it must be pointed out that the plain present tense used for habitual and other meanings contrasts with the present progressive, which encodes an actual occurrence of a dynamic action observed in the process of happening, as in Tim is working late today. The trees are already losing their leaves. (Angela Downing and Philip Locke, English Grammar: A University Course, 2nd ed. Routledge, 2006)

The Cholula Massacre by Cortes

The Cholula Massacre by Cortes The Cholula massacre was one of the most ruthless actions of conquistador Hernan Cortes in his drive to conquer Mexico. Learn about this historic event. In October of 1519, Spanish conquistadors led by Hernan Cortes assembled the nobles of the Aztec city of Cholula in one of the city courtyards, where Cortes accused them of treachery. Moments later, Cortes ordered his men to attack the mostly unarmed crowd. Outside of town, Cortes Tlaxcalan allies also attacked, as the Cholulans were their traditional enemies. Within hours, thousands of inhabitants of Cholula, including most of the local nobility, were dead in the streets. The Cholula massacre sent a powerful statement to the rest of Mexico, especially the mighty Aztec state and their indecisive leader, Montezuma II. The City of Cholula In 1519, Cholula was one of the most important cities in the Aztec Empire. Located not far from the Aztec capital of Tenochtitlan, it was clearly within the sphere of Aztec influence. Cholula was home to an estimated 100,000 people and was known for a bustling market and for producing excellent trade goods, including pottery. It was best known as a religious center, however. It was home to the magnificent Temple of Tlaloc, which was the largest pyramid ever built by ancient cultures, bigger even than the ones in Egypt. It was best known, however, as the center of the Cult of Quetzalcoatl. This god had been around in some form since the ancient Olmec civilization, and worship of Quetzalcoatl had peaked during the mighty Toltec civilization, which dominated central Mexico from 900–1150 or so. The Temple of Quetzalcoatl at Cholula was the center of worship for this deity. The Spanish and Tlaxcala The Spanish conquistadors, under ruthless leader Hernan Cortes, had landed near present-day Veracruz in April of 1519. They had proceeded to make their way inland, making alliances with local tribes or defeating them as the situation warranted. As the brutal adventurers made their way inland, Aztec Emperor Montezuma II tried to threaten them or buy them off, but any gifts of gold only increased the Spaniards insatiable thirst for wealth. In September of 1519, the Spanish arrived in the free state of Tlaxcala. The Tlaxcalans had resisted the Aztec Empire for decades and were one of only a handful of places in central Mexico not under Aztec rule. The Tlaxcalans attacked the Spanish but were repeatedly defeated. They then welcomed the Spanish, establishing an alliance they hoped would overthrow their hated adversaries, the Mexica (Aztecs). The Road to Cholula The Spanish rested at Tlaxcala with their new allies and Cortes pondered his next move. The most direct road to Tenochtitlan went through Cholula and emissaries sent by Montezuma urged the Spanish to go through there, but Cortes new Tlaxcalan allies repeatedly warned the Spanish leader that the Cholulans were treacherous and that Montezuma would ambush them somewhere near the city. While still in Tlaxcala, Cortes exchanged messages with the leadership of Cholula, who at first sent some low-level negotiators who were rebuffed by Cortes. They later sent some more important noblemen to confer with the conquistador. After consulting with the Cholulans and his captains, Cortes decided to go through Cholula. Reception in Cholula The Spanish left Tlaxcala on October 12 and arrived in Cholula two days later. The intruders were awed by the magnificent city, with its towering temples, well laid-out streets and bustling market. The Spanish got a lukewarm reception. They were allowed to enter the city (although their escort of fierce Tlaxcalan warriors was forced to remain outside), but after the first two or three days, the locals stopped bringing them any food. Meanwhile, city leaders were reluctant to meet with Cortes. Before long, Cortes began to hear of rumors of treachery. Although the Tlaxcalans were not allowed in the city, he was accompanied by s ome Totonacs from the coast, who were allowed to roam freely. They told him of preparations for war in Cholula: pits dug in the streets and camouflaged, women and children fleeing the area, and more. In addition, two local minor noblemen informed Cortes of a plot to ambush the Spanish once they left the city. Malinche's Report The most damning report of treachery came through Cortes mistress and interpreter, Malinche. Malinche had struck up a friendship with a local woman, the wife of a high-ranking Cholulan soldier. One night, the woman came to see Malinche and told her that she should flee immediately because of the impending attack. The woman suggested that Malinche could marry her son after the Spanish were gone. Malinche agreed to go with her in order to buy time and then turned the old woman over to Cortes. After interrogating her, Cortes was certain of a plot. Cortes' Speech On the morning that the Spanish were supposed to leave (the date is uncertain, but was in late October 1519), Cortes summoned the local leadership to the courtyard in front of the Temple of Quetzalcoatl, using the pretext that he wished to say goodbye to them before he left. With the Cholula leadership assembled, Cortes began to speak, his words translated by Malinche. Bernal Diaz del Castillo, one of Cortes foot soldiers, was in the crowd and recalled the speech many years later: He (Cortes) said: How anxious these traitors are to see us among the ravines so that they can gorge themselves on our flesh. But our lord will prevent it....Cortes then asked the Caciques why they had turned traitors and decided the night before that they would kill us, seeing that we had done them nor harm but had merely warned them against...wickedness and human sacrifice, and the worship of idols...Their hostility was plain to see, and their treachery also, which they could not conceal...He was well aware, he said, that they had many companies of warriors lying in wait for us in some ravines nearby ready to carry out the treacherous attack they had planned... (Diaz del Castillo, 198-199) The Cholula Massacre According the Diaz, the assembled nobles did not deny the accusations  but claimed that they were merely following the wishes of Emperor Montezuma. Cortes responded that the King of Spains laws decreed that treachery must not go unpunished. With that, a musket shot fired: this was the signal the Spanish were waiting for. The heavily armed and armored conquistadors attacked the assembled crowd, mostly unarmed noblemen, priests and other city leaders, firing arquebuses and crossbows and hacking with steel swords. The shocked populace of Cholula trampled one another in their vain efforts to escape. Meanwhile, the Tlaxcalans, traditional enemies of Cholula, rushed into the city from their camp outside of town to attack and pillage. Within a couple of hours, thousands of Cholulans lay dead in the streets. Aftermath of the Cholula Massacre Still incensed, Cortes allowed his savage Tlaxcalan allies to sack the city and haul victims back to Tlaxcala as slaves and sacrifices. The city was in ruins and the temple burned for two days. After a few days, a few surviving Cholulan noblemen returned, and Cortes bade them tell the people that it was safe to come back. Cortes had two messengers from Montezuma with him, and they witnessed the massacre. He sent them back to Montezuma with the message that the lords of Cholula had implicated Montezuma in the attack and that he would be marching on Tenochtitlan as a conqueror. The messengers soon returned with word from Montezuma disavowing any involvement in the attack, which he blamed solely on the Cholulans and some local Aztec leaders. Cholula itself was sacked, providing much gold for the greedy Spanish. They also found some stout wooden cages with prisoners inside who were being fattened up for sacrifice: Cortes ordered them freed. Cholulan leaders who had told Cortes about the plot were rewarded. The Cholula Massacre sent a clear message to Central Mexico: the Spanish were not to be trifled with. It also proved to Aztec vassal states- of which many were unhappy with the arrangement- that the Aztecs could not necessarily protect them. Cortes hand-picked successors to rule Cholula while he was there, thus ensuring that his supply line to the port of Veracruz, which now ran through Cholula and Tlaxcala, would not be endangered. When Cortes finally did leave Cholula in November of 1519, he reached Tenochtitlan without being ambushed. This raises the question of whether or not there had been a treacherous plan in the first place. Some historians question whether Malinche, who translated everything the Cholulans said and who conveniently provided the most damning evidence of a plot, orchestrated it herself. The historical sources seem to agree, however, that there was an abundance of evidence to support the likelihood of a plot. References Castillo, Bernal DiÃŒ az del, Cohen J. M., and Radice B.  The Conquest of New Spain. London: Clays Ltd./Penguin; 1963. Levy, Buddy.  Conquistador: Hernan Cortes, King  Montezuma, and the Last Stand of the Aztecs.  New York: Bantam, 2008. Thomas, Hugh.  The Real Discovery of America: Mexico November 8, 1519. New York: Touchstone, 1993.

Critical Analysis of studies regarding Austim and whether vaccinations Essay

Critical Analysis of studies regarding Austim and whether vaccinations are the cause - Essay Example the disorder is not been linked to ignorance or carelessness but is linked to MMR vaccination, which is used to immunize children against measles, mumps and rubella. It is hypothesized that since 1980, when the vaccinations was made available to people from all the classes in the society, the development in autism has increased substantially (KNOW. . ., n.d., para 5). Not only that, but because of this hypothesis, parents are concerned about the reliability of the vaccination to such an extend that even the scientific studies contradicting this hypothesis are not helping to develop trust in safety of vaccines. There are numerous studies conducted by scientists and researchers to find if MMR vaccine causes development of autism and most of the studies have found no evidence of relationship between MMR vaccine and increase in risk of developing autism. Smeeth et al., in their article ‘MMR vaccination and pervasive developmental disorders: a case-control study’, describe a study conducted to find out if there was any relationship between the MMR vaccine and the increase in the risk of autism. The intention of the study was to see if MMR vaccine causes autism (Smeeth et al., 2004, p.963). The method that was used to study if an increase in risk of autism or other PDD’s is associated with MMR vaccine was a case control method(Smeeth et al., 2004, p.963). The data of the population for study was taken from UK General Practice Research Database (GPRD), which was set up in 1987. The strength of this study was the availability of the data that consisted of electronic clinical records of the patients registered with all the practices in England and Wales and hence, was not limited (Smeeth et al., 2004, p.963). The data also

Mirrors in the art Essay Example | Topics and Well Written Essays - 1000 words

Mirrors in the art - Essay Example Mirrors were used in European art with the development of Christianity. The symbols of beauty, inner-knowledge, vanity, and fertility of the mirror are expressed. As they became more popular and more accessible, mirrors were used in self portraits and in paintings. It is an important point to make that might not be clear. As the church became the controlling facture in Europe, there started to be sub-cultures. It can be explained with music. All pieces of music were written for the church. "Folk songs" were written with the same music but with different words. As with music, the mirror was used to show two aspects: one aspect done for the church and a second aspect done for the people. The symbols and position of the mirror will be looked at in the 15 and 16th century then it will be compared to the 19th 20th century where the church no longer controlled culture across Europe. Van Eyck's, Marriage portrait of Giovanni Arnolfini and his wife . The mirror, showing 180Â ° vision of the room, shows the full window and how bright it is outside. There is a third person in the mirror. Some say it is a self portrait of Van Eyck. The frame has the scenes of Christ. This is a perfect illustration of church, fertility, light, enlightenment and the mixture of society with the Church. Diego Velazquez, the Spanish painter born in 1656, painted the scene The Maids of Honor. It shows a group of children and their servants, the child of Philip IV, the king of Spain, is watching Velazquez paint an oil canvas. The viewer has to look carefully to find the secret of the painting. On the back wall, he can see the reflexion in the mirror of a couple. He notices that there are the children looking forward and someone in the hallway who is looking in. The man and woman in the mirror are the parents of the princess, the King and Queen of Spain. Philip IV was in the last years of his life and did not want to be painted. There is speculation as if it is the royal couple being painted. Ve rmeer's Girl with a Pearl Earring shows purity. Her earring is a sign of what is going on in her world. The women in his paintings are educated, knowledgeable and enlightened. The light displayed by the earring is bright as a mirror. One can imagine seeing his own reflexion. Most of the young women in his paintings wear pearl earrings. This one has a mirror like quality. Though Degas shows his danseurs in mirrors, he has not left the impressionist school in his later painting, At the Milliner, (Lazzari & Schlesier 60). It must be noted that the woman is looking into a mirror that we cannot see. We know it is a mirror because her friend is looking away. It would have

Barbie-Q Essay Example for Free

Barbie-Q Essay In Sandra Cisneross Barbie-Q, a sudden abundance of flawed Barbie dolls makes the child narrator accepts her own identity and discards societys ideals of women. The initial storyworld is that of materialism and perfection. What the narrator values in her dolls and what she plays with them could be seen as a reflection of her own self image, of what she thinks she should look like and what kind of life she should live. From the first few lines of the story it becomes clear that the narrator of the story is a little girl. She describes the outfits of her barbies, as if reading from the package, to her friend. Yours is the one with mean eyes and a ponytail. Striped swimsuit, stilettos, sunglasses, and gold hoop earrings. The dolls mean eyes reveals the authors critical attitude towards the ideal it represents. This attitude also shows in the title of the story. The Narrator uses second person, as if directly adressing the reader. Who she is talking to is never defined in the story, but it is clear that she is talking to a fellow child. The narration mainly uses only first and second person, which realistically recreates the world of a little girl, where the narrator and her friend are the only people and Barbie dolls the only things that matter. In the second paragraph, the girls repeat societys gender roles in their play: Every time the same story. Your Barbie is roommates with my Barbie, my Barbies boyfriend comes over and your Barbie steals him, okay? The invisible Ken doll could be seen as the authors way of emphasising her point about societys assuptions of young womens interests. The author makes the scene strange enough to catch the readers attention. The flea market scene describes the mundane reality of the narrators neighbourhood which is contrasted with the girls aspirations that are projected to barbie dolls that represent a different social background and lifestyle. The narrator lists the items in the flea markets just like she did with her dolls: Lying on the street next to some tool bits, and platform shoes with the heels all squashed, and a fluorescent green wicker wastebasket, and aluminum foil, and hubcaps, and a pink shag rug, and windshield wiper blades, and dusty mason jars, and coffee can full of rusty nails. This emphasises the contrast. The initial story world is disrupted in the flea market scene as the narrator finds flawed Barbies for sale. This scene develops in the next paragraph as the narrator gets all the Barbies she dreamed of, only all of them damaged by a fire. In the last paragraph, the narrator seems to accept her own social background as she understands that it doesnt matter that they cant afford all the new Barbie dolls. So what if we didnt get our new Bendable Legs Barbie and Midge and Ken and Skipper and Tutti and Todd and Scooter and Rickie and Alan and Francie in nice clean boxes and had to buy them on Maxwell Street, all water-soaked and sooty. The narrator describes her flawed Barbie: And if the prettiest doll, Barbies MODern cousin Francie with real eyelashes, eyelash brush included, has a left foot thats melted a little-so? This statement could be seen as having a wider meaning, that the child also accepts her own flaws and ends her quest for perfection defined by society.

Essay --

â€Å"America the land of opportunities is currently going through one of the worst poverty rates in over 50 years† said Michael Karibian researcher and journalist on poverty. Many people are in poverty and they have no one to blame but themselves. People remain in poverty for the reason that they do not have the desire to change and be successful and take charge of their own life; anyone can avoid poverty although the problem is people’s attitudes towards change. It can be easy to simply give up and blame others for their misfortune but in reality those people only have themselves to blame for their own misfortune in life. Getting out of poverty is difficult but it is not impossible for those who are willing to take control of their lives and no longer be a victim of thee own mistakes. America has opportunities for everyone who desires to avoid poverty by making smart choices, getting a good education and neglecting bad influences. People are quick to blame the government for all the poverty in America when in reality they only have themselves to blame for their own misfortune. â€Å"They didn’t run as fast as everyone else, and if they ran faster, they’d do better† said Allan G. Johnson. The point of this quote is that if people do not try to get themselves back up they will not succeed and stay where they are at. It is true that there are uncontrollable external factors built into politics that can intensify the challenges to make the smartest choices, which are not always the easiest or obvious, but the blame must be placed on individuals because poverty has a partial but direct correlation to individuals choices they make. A reason for the poverty rates in America are because communities have established a poverty culture. An article ... ... the line by trying them. Girls who get pregnant at a young age have no one to blame but themselves unless they were raped. All these things can happen to both rich people and poor people although people that live in poverty will have a harder time getting past all the negative influences then rich people, but that does not mean it is not impossible for them to have a successful life as long they focus on being successful anyone form any background can make it in life. Living in poverty is not a matter of bad luck it is a matter of individuals lacking the determination to be someone in life and always trying to take the easy way out. Those who are determined in life can be anything they want no matter their background. America has opportunities for everyone who desires to avoid poverty by making smart choices, getting a good education and neglecting bad influences.

Computer Studies

1 GCSE Computing Revision Booklet This booklet has been created to provide an overview of each of the topics that you need to revise. Each section is broken down and guidance given on what you need to know. Use it in conjunction with your own revision techniques, e. g. mindmaps, to prepare for the exam. Name: †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 2 Fundamentals of Computer SystemsYou need to be able to: (a) define a computer system (b) describe the importance of computer systems in the modern world (c) explain the need for reliability in computer systems (d) explain the need for adherence to suitable professional standards in the development, use and maintenance of computer systems (e) explain the importance of ethical, environmental and legal considerations when creating computer systems. What is a computer sys tem? At its very basic, a computer system nothing more than an input, a processor and an output. InputProcessor Output A computer system will usually have some storage capability and more often now – a way of communicating with other devices. Computers are all around us and I’m not just talking about your desktop or laptop computer. Your â€Å"smartphone†, your games console, your ipad, even your Sky+ or freeview recorder is a computer system of sorts. 3 Computer systems are integral parts of our lives. Think about all the computer systems you or your parents use on a daily or weekly basis: Running washing programmes and sensing when clothes are dry.On-board computers to control everything from engine efficiency to voiceactivated MP3/Bluetooth hands-free system. Cashless catering system in school to add and subtract money from your account. Self-service checkouts in supermarkets that scan, weigh, take payment and give change. Contactless card payment systems whe re a small RFID (radio frequency ID) tag is embedded into the card and read when the card is near. RFID technology – often used in library books and shops to detect theft, also has future applications in â€Å"smart† clothes and food products.Imagine the RFID tag in your clothes tells the washing machine how to wash them. Or a smart fridge that knows when the milk is past it’s sell-by date and adds it to your online shopping list. Since we rely so much on technology there are huge problems when it goes wrong! If a supermarket checkout system goes down this could result in lost sales of thousands of pounds. However, if an automated system, like those onboard aircraft fails then it could end in disaster! 4 Why do we need to use the same professional standards when developing and maintaining computer systems?Without standards to adhere to we risk developing systems that are not compatible with each other. Would you be happy if your Nokia mobile could only call othe r Nokia mobiles? Standards also improve the quality of the computer system and its maintenance by ensuring that best practice is followed and people don’t cut corners. Considerations when creating computer systems: The Data Protection Act 1998 provides protection for all information stored on a computer system. It requires the person who owns the system to store the information securely and only use it for the purpose it was originally gathered for, e. . the school holds data on you for the purpose of your education; it cannot sell this data to companies who may wish to sell you things. The speed of progress means that many gadgets become old and obsolete quite quickly. This means there are potentially stockpiles of old technology which could end up in landfill. Many companies now recycle these by selling reconditioned devices to other countries or cannibalising the parts to be used again. Websites like Google use huge server-farms around the world. These buildings are full o f computers running 24/7.There is an impact on the environment from the huge amount of electricity needed to run these server-farms. Technology enables us to do many things. But are they always right? Google’s Street View caused controversy when it was launched after people said that taking photos of their houses was an invasion of privacy. Social networking sites, like Facebook, have made it easier to share information but have made it difficult to set privacy settings. You can now be tracked using GPS technology and Facebook places! Is this the â€Å"Big Brother† state? 5 Computer SoftwareYou need to be able to: (a) explain the need for the following functions of an operating system: user interface, memory management, peripheral management, multi-tasking and security (b) describe the purpose and use of common utility programs for computer security (antivirus, spyware protection and firewalls), disk organisation (formatting, file transfer, and defragmentation), and sy stem maintenance (system information and diagnosis, system cleanup tools, automatic updating) (c) discuss the relative merits of custom written, off the shelf, open source and proprietary software.Operating System functions Memory management User interface The OS manages the transfer of data between the CPU, RAM and main storage (e. g. hard drive) The OS provides the user with a way of controlling the functions of the computer without resorting to machine code. It can be graphical (GUI), e. g. Windows or text-based [no mouse] (CLI – Command Line Interface), e. g. MSDOS. The OS manages the input and output devices connected to the computer, including things like keyboard, mice and printer. The OS allows more than one program to be run at once so users can switch back and forth between applications easily.The OS provides security features to restrict access to the system or particular files. Peripheral management Multi-tasking Security When trying to remember the functions of a n Operating System – think MUMPS! Memory mgt, User interface, Multi-tasking, Peripheral mgt and Security. 6 Utility programs Type Security Purpose Detects and protects the computer against virus threats. Quarantines infected files. Spyware Detects and removes spyware (small protection programs that quietly monitor what you are doing) Firewall Restrict communication in and out of the computer from the applications that are running.Formatting Sets up a hard drive, memory stick or card into a format that the computer can use to store/retrieve data. The process of formatting erases any data that was previously on the storage medium. File Transfer Allows movement of files from one location to another, either locally or via memory stick/FTP to another computer. Defragmentation Re-organises the data on the hard drive to improve read/write access times. System info & Provides information about the diagnosis system in order to help with diagnosis of problems. System cleanup Removes te mporary files and tools compresses/archives unused files to increase free storage space.Automatic Uses the Internet to check the OS updating is up-to-date and applies software patches/fixes as necessary. Program Antivirus Security Security Disk Operations Disk Operations Disk Operations System Maintenance System Maintenance System Maintenance 7 Software development Custom written Developed specifically for a particular organisation. (a. k. a. bespoke/inAdv: custom made to meet exact purpose house) Disadv: very expensive and need technical expertise to develop. Off-the-shelf Developed by a software company to be sold to the general public. Adv: cheaper than developing it yourself and tech support available.Disadv: inflexible – might not do everything you want it to do. Open source Written by general public for everyone else to use. Source code provided so software can be tweaked. Adv: allows anyone to use/adapt the software to meet their needs, collaborative approach to develo pment which can lead to better quality software. Disadv: by making source code available to all, provide opportunity for people to â€Å"take advantage† of software installed on users’ computers compromise security. Proprietary Written by developer and allowed to be used by others but with certain restrictions, e. . can’t adapt software. Source code is hidden. Adv: can allow for different versions of same software, e. g. educational version with limited functionality or fullfunctionality version costing more. Disadv: source code cannot be inspected so may contain spyware or other malicious features within the software. 8 Computer Hardware Definition: Computer hardware refers to the physical parts of a computer and related devices. Internal hardware devices include motherboards, hard drives, and RAM. External hardware devices include monitors, keyboards, mice, printers, and scanners.The internal hardware parts of a computer are often referred to as components, wh ile external hardware devices are usually called peripherals. Source: www. techterms. com Inputs and Outputs (Peripherals) You need to be able to: understand the need for input and output devices (a) (b) describe suitable input devices for a wide range of computer controlled situations (c) describe suitable output devices for a wide range of computer controlled situations discuss input and output devices for users with specific needs. (d) Inputs and outputs are the computers way of communicating with us – the user.Without inputs or outputs our system would be quite limited. Imagine a calculator which didn’t allow you to type in numbers or display the answer on the screen! Here are some of the common input devices used: Keyboard The keyboard, along with the mouse, is one of the most used input devices. Once you get the hang of where the keys are, it allows people to enter textbased data quickly into the computer. A numerical keypad (found on most keyboards on the right) provides a fast way for accountants and people who work in finance to enter numbers. 9 There are some interesting variations on the keyboard:Roll-up keyboard (portable – can be rolled up and stuffed in laptop bag) Wireless keyboard (no need for messy wires, frees up user needing to be near computer) Laser Projection (projects a keyboard layout on to any surface; sensors detect which â€Å"keys† have been pressed) Mouse The computer mouse is another common input device. It allows the user to interact with the software on screen. The mouse is quite versatile, with at least two buttons and the ability to move in any direction. However, it can be difficult to be precise – e. g. drawing using the mouse is quite hard! Mice have also undergone a few changes over the years as well:Laptop touchpad (touch-sensitive pads that allow the mouse to be controlled by just a finger) Trackball (the user moves the pointer on-screen by moving rolling the ball; the unit doesnâ€℠¢t move around like the mouse) Optical Mouse (old mice used balls which used to get clogged with dirt and grease – new mice use small cameras to detect movement instead). 10 Other Input Devices Scanner Scanners convert physical documents and photos into digital format. They can be used in conjunction with special software to automatically read handwriting and convert it into computer text. This is called Optical Character Recognition.Some tickbox forms are scanned in, like the Census form or your multiple choice Science exams; this is called Optical Mark Recognition. Touchscreen Touchscreens have been around for years in one form or another. The latest versions, like the Apple ipad interface use multi-touch technology to allow greater control. Microphone Microphones convert analogue sounds into a digital format that the computer can understand and playback. Sounds are usually recorded as . wav or . mp3 files (the latter uses compression to make the file size smaller and is mo re likely to be used to store music tracks).Digital Camera Digital cameras convert live images into digital format. Photos are usually stored as JPEG files. The quality and size of the picture is determined by the number of megapixels the camera is capable of detecting, e. g. photos taken with an 8 megapixel camera are made up of 8 million pixels. 11 Webcam Webcams capture live video feeds and using appropriate software can then transmit those across a network. Sensors Sensors measure the physical world and translate that into a digital format that a computer can understand. There are various sensors that detect ll manner of things: movement, light, heat, moisture, gases (e. g. carbon monoxide levels), location (GPS), etc. For example, the iPhone has an accelerometer so it knows which way round it is to ensure the screen is rotated the correct way. Output Devices Printer Printers produce physical documents and photos from digital files. Most photo printing is done by inkjet printers which can be expensive to run. Laser printers use toner cartridges which are more expensive initially but can print more pages before being replaced. 12 Monitor/screen Monitors/screens provide the visual output from the computer system.Most computer monitors and mobile phones use colour LCD (liquid crystal display). Speakers Working the opposite way to the microphone input, the speaker converts digital sound into analogue waves. 3D Printer A 3D printer uses lasers and a special kind of plastic to build physical 3D shapes from drawings made using CAD software (computer aided design). The object is built up layer by layer. The whole process can take many hours before the final product is finished. They are often used for creating prototypes in manufacturing, e. g. Dyson uses them to create prototype parts for their products.They are still very expensive but the price is coming down. Motor A motor can be driven with precision by a computer system. Often used in manufacturing, e. g. bu ilding cars, motors are used to control robotic arms. 13 Input and output devices for specific needs Keyboards have been adapted for users with limited movement in their arms/hands. A keyboard designed to minimise the movement of your hands. Trackballs have also been used where users only have limited motor ability. They can be used by hands or feet, like the one below: A foot-operated mouse, ideal for people with limited/no mobility in their arms.For quadriplegic users, there are two alternatives to using the mouse or keyboard. The first is voice-recognition; this involves the user reading a passage of text from the screen so the computer â€Å"learns† their voice pattern. They can then use special software to control the computer using voice commands. The technology is getting better but can still make mistakes. The second is eye-tracking which uses small cameras mounted on the monitor to detect eye movement and move the cursor to the point where the user is gazing. A mouse click is made by blinking slowly.Stephen Hawking uses a special device to allow him to communicate. An infra-red sensor detects twitches in the cheek muscle below his eyes in order to enter words and then his device generates a computer synthesised voice to read them out loud. 14 Internal Hardware Devices (Components) Central Processing Unit (CPU) You need to be able to: (a) state the purpose of the CPU (b) describe the function of the CPU as fetching and executing instructions stored in memory (c) explain how common characteristics of CPUs such as clock speed, cache size and number of cores affect their performance.The purpose of the CPU is to Fetch and Execute instructions stored in memory. It acts as the brain of the computer and controls the rest of the system. INPUTS and OUTPUTS CPU RAM 15 Fetch Execute Cycle (using Little Man Computer) Download the software: http://www. cs. ru. nl/~erikpoll/III/lmc. Allows you to quit out of the current program and go back to the Start This d isplays which phase of the fetch/execute cycle we are currently in. The program that is currently being carried out. The current instruction is the one in line with the phase display. Provides the name of the current instruction, along with it's op code and operand.This explains what the little man is doing at each stage as he follows the program. Fetch phase Before the little man can carry out an instruction, he needs to find out which instruction he has to carry out. He does this by first getting the value from the program counter (The thing that looks like a green mushroom in a block of wood), and then fetching the value from the corresponding address in memory. The Program Counter The little man uses the value in the program counter to decide which address in memory he should get the next instruction from.After getting the value, but before going and getting that instruction, he increments the program counter, so that it has the correct value in it when he visits it next time. M emory Memory can be used to store programs, and data. In the fetch phase of the fetch execute cycle we are only interested in the fact that we can get instructions from the memory. 16 Execute phase Once the little man knows which instruction he is going to perform, he has to set about actually doing it. This is the ‘Execute' phase of the fetch execute cycle. For each instruction the little man will perform a series of tasks.For instance, for an input instruction, the little man will go to the input tray, take the value he finds there, and go and put it into the calculator. For an add instruction, he will take a value from memory, and add it to the value presently in the calculator. Once the execute phase is complete, the little man will start the cycle again, and head to the program counter to get the value of the next instruction he has to fetch. The Input and Output trays These are what we (the user) use to communicate with the little man. We provide him with data via the in put tray, and when he's ready, he provides us with data via the output tray.Calculator (Arithmetic Logic Unit – ALU) On a ‘real' computer, this would be the Arithmetic Logic Unit (ALU). It’s basically a calculator that will carry out arithmetic operations. Memory Memory is accessed during the execute phase when we need to store or access data. It is possible to overwrite your programs when putting data into memory though, so be careful where you put it. Following a program (Decoding instructions) The program is a series of instructions made up of an op code and operand (either data or the address where data is stored).For example: Op code Operand 1 2 3 4 5 6 7 800 801 802 9 Load Store Add Subtract Input Output Halt Skip If Negative Skip If Zero Skip If Positive Jump 2 means â€Å"Store† 2 99 99 refers to the memory address where little man should store the data. These can be stored as binary bit patterns, e. g. 10 could refer to the op code (2) above and 1 1000011 could refer to the memory address (99). Remember 2 in binary is 10 and 99 is 11000011. This would give the bit pattern for the above instruction as 1011000011 Q. How does little man (CPU) know the difference between data or an instruction?It all depends on which phase of the cycle the CPU is in, e. g. in the Fetch phase the CPU knows it is an instruction. In the Execute phase the CPU knows it is data. Op codes understood by LMC 17 Characteristics which affect performance Clock Speed This is the number of cycles that the CPU can complete in one second (measured in Hertz or Hz) A faster clock speed means the CPU can process more instructions per second. For example a 1MHz processor can process 1 million instructions a second; whereas a 1GHz processor can do 1000 million instructions in the same time.This is the A larger cache size means holding area for more data can be held and data from the it’s less likely that any cycles are wasted. A RAM. It ensures the CPU smaller cache size and is always busy fast clock speed may with data. result in a bottleneck between the RAM and CPU. A dual-core processor or This is the quad-core processor is 2 number of processing cores to 4 times faster than a conventional chip as they the CPU has. A can process simultaneous dual-core has instructions. two and is able to process two instructions simultaneously in the same cycle. Cache sizeNumber of Cores It is important to balance all of the above to avoid â€Å"over-speccing† one area and creating bottlenecks elsewhere. 18 Memory You need to be able to: (a) describe the difference between RAM and ROM (b) explain the need for ROM in a computer system (c) describe the purpose of RAM in a computer system (d) explain how the amount of RAM in a personal computer affects the performance of the computer (e) explain the need for virtual memory (f) describe cache memory (g) describe flash memory (h) discuss how changes in memory technologies are leading to innovative c omputer designs.RAM and ROM Both are needed in a computer system but for different reasons. In a computer computer, ROM (Read Only Memory) is used to store all the instructions (the BIOS – Basic Input/Output System) to get the computer up and running. It seeks out the amount of memory, input and outputs available to it and then loads up the operating system. In some computer systems, like your washing machine, the ROM stores the software to control the hardware, as well as data such as cooking/washing times etc.RAM (Random Access Memory) is used as temporary storage for instructions and data between the inputs, outputs, secondary storage (e. g. hard drive) and CPU. The larger the RAM, the more instructions/data can be held in quick access memory without needing to use Virtual memory; this can improve performance. Random Access Memory Read Only Memory Volatile (forgets everything when power switched off) Non-volatile (remembers content even if power switched off) Can be writte n to and read from Can only be read from (not written to) Usually measured in Gigabytes (Gb) For the BIOS, usually measured in Kilobytes (Kb) 9 Virtual Memory Depending on the size of the RAM, it is not always possible to store all the running programs in the RAM at once and the computer will start running low on memory and slow down. This is where virtual memory comes in. It stores the data that the RAM isn’t actively using on the hard drive to free up the RAM. Then, when the CPU needs the data it pulls it back from the virtual memory on the hard drive. As far as the CPU is concerned, all the programs are running from the RAM. The operating system sets up a page file on the hard drive to be used for virtual memory.This is usually set at twice the size of the amount of RAM, e. g. 1GB of RAM should have a 2GB page file. Cache Memory This has been explained in the CPU section on page 17. Flash Memory Flash Memory is often referred to as solid-state storage, which means that the re are no moving parts. It’s similar to RAM but is non-volatile which means when the power is cut off, it still remembers the content). Flash memory is used in USB memory sticks and memory cards for digital cameras and some games consoles, e. g. Sony PSP.Future developments in Memory technologies Physical Size & Capacity Costs Speed Power Memory chips have become more compact (storing more bits per chip) which has lead to smaller computing devices and larger capacities. The cost of memory has fallen which means it is now affordable to have large amounts of RAM available. Read/write times are improving which mean faster access and better performance. Memory chips are more power-efficient meaning portable devices work for longer between charges and batteries can be smaller and lighter. 20 Secondary StorageYou need to be able to: (a) explain the need for secondary storage (b) describe common storage technologies such as optical, magnetic and solid state (c) select suitable stora ge devices and storage media for a given application and justify their choice using characteristics such as capacity, speed, portability, durability and reliability. Secondary storage is needed for when we want to store files permanently or semi-permanently. We might want to transfer files between computers by using portable secondary storage media. Storage TechnologiesCodes data using microscopic dips on the surface of the disc. Units Optical Codes data using small changes in magnetic fields. Magnetic Uses non-volatile memory chips to store bits of data Solid State Candidates should be able to: (a) define the terms bit, nibble, byte, kilobyte, megabyte, gigabyte, terabyte Bit 1 Nibble 4 bits Byte 8 bits Kilobyte (Kb) 1,024 bytes Megabyte (Mb) 1,024 kilobytes Gigabyte (Gb) 1,024 megabytes Terabyte (Tb) 1,024 gigabytes 21 Storage Media Comparison Storage Medium CD Method Optical Capacity Medium 650-700Mb Small 1. 4Mb Large 1Gb to 2+ Tb Speed Fast access Portability Lightweight and fl at Lightweight and flat Heavy and not designed to be carried around. Requires integrating into computer system. Medium-weight. Plugs into computer USB or Firewire port. Lightweight and small. Durability and Reliability Easily scratched and will then not work. Can only be written to once. Can be snapped. Can be damaged by strong magnets or heat. Quite reliable but can crash – when the read/write head crashes into the platter. Sometimes happens on laptops when dropped. Can be damaged by magnets.Same concerns as internal hard drive. Floppy Disk Magnetic Slow access Internal Hard Disk Magnetic Fast access (dependent on speed of motor RPM – rotations per minute) Portable Hard Disk Magnetic Large 40Gb to 640Gb Medium-fast access (dependent on connection method, e. g. USB cable) Flash drive (USB stick or memory card) Blu-ray disc DVD (Digital Versatile Disc) Solidstate Optical Optical Medium/Larg Medium-fast access e (dependent on connection 1Gb to 64Gb method, e. g. USB cabl e or card reader) Large Fast access 50Gb Large Fast access 4. 7Gb Not affected by magnets.Quite hardy. Can be dropped without damaging contents. Easily scratched and will then not work. Easily scratched and will then not work. Lightweight and flat. Lightweight and flat. 22 Binary Logic You need to be able to: (a) explain why data is represented in computer systems in binary form (b) understand and produce simple logic diagrams using the operations NOT, AND and OR (c) produce a truth table from a given logic diagram. Computers use binary as it's a lot simpler. Each CPU is made up of millions of transistors which can only have two states (ON/OFF).Anything can be converted into a binary number so a computer can understand, process and store it. NOT Gate NOT Truth Table Input Output 0 1 1 0 Flips the input, e. g. 0 becomes 1 and 1 becomes 0. AND Gate a b Waits for 1 on both inputs before outputting a 1. AND Truth Table Input Input Output a b 0 0 0 0 1 0 1 0 0 1 1 1 OR Gate a b Wait for 1 on either input before outputting a 1. OR Truth Table Input Input Output a b 0 0 0 0 1 1 1 0 1 1 1 1 You can practice with NOT, AND and OR gates using the following website: http://logic. ly/demo/ 23 Representation of data in computer systemsNumbers You need to be able to: (a) convert positive denary whole numbers (0-255) into 8-bit binary numbers and vice versa (b) add two 8-bit binary integers and explain overflow errors which may occur (c) convert positive denary whole numbers (0-255) into 2-digit hexadecimal numbers and vice versa (d) convert between binary and hexadecimal equivalents of the same number (e) explain the use of hexadecimal numbers to represent binary numbers. Denary and Binary conversions Numbers greater than 1 can be represented in binary by using more bits. e. g. 129 can be represented in 8 bit (byte) binary as 10000001.Denary Binary 128 1 64 0 32 0 16 0 8 0 4 0 2 0 1 1 This means that if you put a 1 on each increased by double bit (i. e. 11111111) the highest denary for each new bit added to the left. number 8 bits (a byte) can store is 255; 128+64+32+16+8+4+2+1 = 255. Notice how the number To convert binary into denary, just add together the denary numbers above each bit that has 1 in it, e. g. 10000001 = 128 + 1 = 129. To convert a denary number into binary, find the highest value that will go into it and then continue down the number of bits with the remainder until there is nothing remaining. 4 For example, to convert 44 into binary 8-bit format: 44 is smaller than 128 and 64 so we place 0s in those bits: Denary Binary 128 0 64 0 32 does go into 44 with remainder of 12, so we place a 1 in that bit: Denary Binary 128 0 64 0 32 1 The remainder of 12 is smaller than 16 so we place a 0 in that bit: Denary Binary 128 0 64 0 32 1 16 0 8 does go into 12 with remainder of 4, so we place a 1 in that bit: Denary Binary 128 0 64 0 32 1 16 0 8 1 4 does go into 4 with with nothing remaining, so we place a 1 in that bit: Denary Binary 128 0 64 0 32 1 16 0 8 1 4 1 nd 0s in all the remaining bits: Denary Binary 128 0 64 0 32 1 16 0 8 1 4 1 2 0 1 0 Therefore 44 as an 8-bit binary number is: 00101100. 25 Adding two binary numbers together Adding two binary numbers together is not as scary as it sounds or looks. It uses the same principles at the denary number system (Hundreds, Tens, Units). For example: Work from right to left, like you do when adding denary numbers using HTUs. 00010010 + 00010100 0+0=0 0+0=0 0+0+1 1+1=0 0+0=0 0 0 11 0 0 1 1 0 0+0=0 1+0=1 0+1=1 (carried over) = 1 (carry 1)Let’s convert it back into denary to check it is correct: Denary 128 Binary 0 16 + 2 = 18 Denary 128 Binary 0 16 + 4 = 20 Denary 128 Binary 0 32 + 4 + 2 = 38 64 0 32 0 16 1 8 0 4 0 2 1 1 0 64 0 32 0 16 1 8 0 4 1 2 0 1 0 64 0 32 1 16 0 8 0 4 1 2 1 1 0 So as 18 + 20 are 38. Then we know the binary calculation is correct! 26 Hexadecimal Numbers Programmers started to use hexadecimal to reduce mistakes and make it easier for them to underst and than using lots of 0s and 1s. Denary and hexadecimal conversions Hexadecimal uses a base 16 system = 0-9 and then A-F.That means that the denary number 15 is equal to F in hexadecimal. The denary number 16 is equal to 10 in hexadecimal (which means 1 lot of 16) The highest denary number represented in 8-bit (byte) binary is 255 and was represented by 11111111. In hexadecimal this would be represented as FF (15 lots of 16 + 15). Confused?! Remember, F in hexadecimal represents 15. Therefore F0 would be 15*15=240. The second F is 15, therefore FF = 240+15 = 255. To convert denary to hexadecimal you can divide the number by 16. For example, to convert 141 into hexadecimal do the following: 141 / 16 = 8 remainder 13. /16 = 0 remainder 8. Therefore, working from right to left, the hexadecimal number is 8 13 (and 13 is represented as D in hex) so it would be 8D. Alternatively, convert the denary number into binary and then binary to hexadecimal. 27 Binary to hexadecimal conversions To convert binary to hexadecimal you need to break it down into nibbles (blocks of 4 bits). For example, 141 as a binary number is: 10001101. The two nibbles are 1000 and 1101. Converting each nibble into denary we can see that 1000 = 8 and 1101 = 13.Remembering that 13 = D in hexadecimal then 141 would be represented as 8D. To convert hexadecimal to binary you just reverse the process. Convert each part of the hexadecimal number into nibbles of binary numbers. For example: Hex Denary Binary 8 8 1 4 0 nibble D 2 0 1 0 8 1 4 1 nibble 2 0 1 1 HELP! This conversion chart below may help to make sense of it all! Denary 0 1 2 3 4 5 6 7 Binary 0000 0001 0010 0011 0100 0101 0110 0111 Hexadecimal 0 1 2 3 4 5 6 7 Denary 8 9 10 11 12 13 14 15 Binary 1000 1001 1010 1011 1100 1101 1110 1111 Hexadecimal 8 9 A B C D E F 8 Using binary to represent characters You need to be able to: (a) explain the use of binary codes to represent characters (b) explain the term character set (c) describe with exampl es (for example ASCII and Unicode) the relationship between the number of bits per character in a character set and the number of characters which can be represented. Computers use the ASCII (American Standard Code for Information Interchange) format to use binary codes to represent numbers, letters and special characters. It uses 8-bits (byte) to represent each character, so every character has it’s own unique 8-bit ASCII code.Using the ASCII character set on the next page we can convert characters into binary numbers. For example, Isambard would be represented in binary as: I s a m b a r d = = = = = = = = 73 115 97 109 98 97 114 100 = = = = = = = = 0100 1001 0111 0011 0110 0001 0110 1101 0110 0010 0110 0001 0111 0010 0110 0100 Notice how the capital I is different from the lowercase i in the ASCII format. An upper and lower case version of each letter is present in the chart to enable the computer to tell the difference between them. If you remember what we said about binar y numbers back on page 23 then you know that 8-bits (a byte) can store up to 255 in denary.This means that the ASCII format can have up to 255 characters represented in a character set. 29 American Standard Code for Information Interchange character set Note: You don’t need to remember these codes for your exam but just be aware of how it works. 30 Using binary to represent images You need to be able to: (a) explain the representation of an image as a series of pixels represented in binary (b) explain the need for metadata to be included in the file such as height, width and colour depth (c) discuss the effect of colour depth and resolution n the size of an image file. Images on the computer are made up of lots of individual pixels (small squares of colour). If you zoom into any image enough times you will see these little blocks of colour. We can use binary numbers to represent each pixel. In a simple image, where there are only two colours (colour depth of 1) then we can si mply use a 1 for one colour, and 0 for another. For example, look at this small 3 x 3 pixel image below. The 1s represent the black colour and the 0s represent the white. 0 0 0 1 0 0 0 1 31 That is the principle behind storing images as binary. However, we also need to know a few other things about the image in order to display it correctly, i. e. its height, width and colour depth. Image Metadata Height Width Colour depth Resolution The height of the image in pixels The width of the image in pixels The number of bits available to represent each pixel The pixels per inch (PPI) – if the pixels per inch is high, then the resolution and image quality is also high.Without this metadata the computer would not be able to reconstruct the image properly. Colour Depth In a simple 1-bit colour depth image, we can only display two colours. However, in an 8-bit colour depth image (like the gif format), we can display 256 colours (one for each binary number from 00000000 to 11111111). In a 24-bit colour depth image (like the jpeg format), we can display just over 16 million colours! If we use more bits to store each pixel, then the file size will be larger. That is why . gif images are often smaller in file size than . peg images. Resolution If the image has a higher resolution, it has more pixels to store data about and is therefore larger in size. If the image is lower resolution, this means that there are less pixels per inch, which means less pixels to store data about and is therefore smaller in size. 32 Using binary to represent sound You need to be able to: (a) explain how sound can be sampled and stored in digital form (b) explain how sampling intervals and other considerations affect the size of a sound file and the quality of its playback.Sound is stored in the computer by taking samples of the sound wave at regular intervals and converting those into binary numbers (using an analogue-to-digital convertor). The computer can then re-create the sound by reve rsing the process. The file size and quality of the sound recording is affected by the sample rate and bit rate. The sample rate refers to the number of samples taken each second. It is measured in Hertz (like the CPU clock speed). If the sound wave is not sampled at a higher enough rate, this can lower the quality of the sound recording, but the file size would be smaller.If the sound wave is sampled at a higher sampling rate, this will increase the quality of the recording, but the file size will be much larger. The bit rate refers to the amount of bits used to store the different levels of sound at each sampling interval. The more bits, the greater range of levels that can be distinguished. This also has the affect of increasing the file size if the bit rate is high (e,g. 16-bit instead of 8-bit). 33 Computer Communications and NetworksNetworks You need to be able to: (a) explain the advantages of networking stand-alone computers into a local area network (b) describe the hardwar e needed to connect stand-alone computers into a local area network, including hub/switches, wireless access points (c) explain the different roles of computers in a client-server and a peer-to-peer network (d) describe, using diagrams or otherwise, the ring, bus and star network topologies (e) describe the differences between a local area network and a wide area network such as the Internet explain the terms IP addressing, MAC addressing, packet and (f) protocols (g) explain the need for security measures in networks, such as user access levels, suitable passwords and encryption techniques (h) describe and justify network policies such as acceptable use, disaster recovery, failover, back up, archiving. Why network? Allows computers to communicate with each other and share resources, e. g. peripherals (printers, scanners), storage, internet access. Data Packets Information is sent around a network in data packets. Data is broken down into packets to be sent over the network and ofte n may take different routes to get there. It contains info on where it needs to go (the address) and the packet number and an error-checking facility to ensure the packet arrives intact and can be put back together in the right order. 34Basic components of a local area network (LAN) Client/ Computer Hub, Switch or Router See next page for explanation of each. Server In a Client-Server network, the server handles the logins, applications and file storage. Modem Interfaces between the Internet and the network. Shared Peripherals Networks allow peripherals like this printer to be shared by all the computers on the network. Internet 35 Hub, Switch or Router? These are not the same. You need to know the difference between them. Hub A hub receives all data sent over the network and sends it to all the other devices on the network. Only the device who the data packet is for will acknowledge it; the other devices will ignore it.A switch is bit more intelligent than a hub and it learns which devices are on the network (and their port number/address) and only sends the data packet to the computer who is the intended recipient. This is more efficient than a hub as it doesn’t result in lots of unnecessary network traffic. A router is cleverer still than both hubs and switches. It can re-direct network traffic and deal with different packets in different ways. It can protect the computers on the network by hiding them from the outside world (i. e. a firewall). Some routers have a modem built-in and wireless capabilities. Most homes have a 4-port wireless broadband router to access the Internet. This combines the router and modem functions. Switch RouterWireless access points don't require a physical connection and therefore are suited for a variety of different devices and provide access to network over an area, e. g. iPad or smartphone. IP address The IP address (Internet Protocol) is a computer's unique address on the network, e. g. 192. 168. 0. 1 is usually your home router's address. On the Internet, each website has its own or several IP addresses. 36 MAC address The MAC address (Media Access Control) is a hexadecimal number that is unique to that particular device. Hey! Did you know that there are 281,474,976,710,656 possible MAC addresses in the world? That’s a lot of MACs baby†¦ huh huh! Network Protocols Protocols are a set of standards and guidelines that tell computers how they should handle the sending and receiving of data over the network.TCP/IP (Transmission Control Protocol and Internet Protocol) Used to exchanged data between computers on a network and route packets between networks and over the Internet. Used on WWW to transfer webpages and web content from the website host server to the computer requesting the page. Used to transfer files between computers over a network. Used to transport emails. HTTP (HyperText transfer Protocol) FTP (File Transfer protocol) SMTP (Simple Mail Transport Protocol) LAN or WAN? A L AN is a Local Area Network which is usually set-up within a certain area, e. g. a building or group of buildings – hence the term â€Å"local†. A WAN is a Wide Area Network which is usually on a nationwide or worldwide scale. The Internet is an example of a WAN – a series of interconnected LANs. 7 Network Topologies A network can be set up in three main ways: Ring 4 3 5 1 2 All the computers are linked together in a ring and data packets are sent one way round. For example in the diagram above to get from PC 1 to PC 5 the data needs to go through PCs 2, 3 and 4. It can’t go anti-clockwise back to PC 5. Drawbacks: If there is one break in the ring then the network breaks down. Also not very efficient as a lot of network traffic doesn’t take the most direct route. Bus All the computers are connected to a central bus. You can add and take away computers easily in a bus network as the computers are connected to the central bus, rather than between one another.Drawbacks: Only one computer can use the bus at once which means only one computer can communicate at a time – the others have to wait until the bus is free before sending their data; this makes it slow. If a computer connected to the bus breaks down, then the network still runs but if the central bus breaks down then so does the whole network. 38 Star 4 3 5 1 2 All the computers are connected to central server. The server can handle multiple communications at once and re-directs traffic over the network. More computers can be added or taken away without affecting the network. Drawbacks: If the main server fails then the network goes down. Client-server and peer-to-peer networks In a Client-server network, the server acts as the main computer handling login requests, user storage, etc.The client could be any computer. The user can log on to any client and still access their stuff on the server. In a Peer-to-peer network, each computer shares information equally and pl ays an equal role in the network. Network Security Part of Data Protection Act 1998 requires companies who store data electronically to keep it safe and secure. Without security then anyone could hack into the network and intercept data packets. Confidential data packets should be encrypted so if they are intercepted they are unreadable. There may be a need to prevent unauthorised access to particular areas of the system; this could be controlled by passwords and different user levels, e. g. n the school a student can only access the student shared drive, whereas teachers can access both the student shared drive and the staff shared drive. 39 Network Management Policies Disaster recovery In the event of the system failing there needs to be plans in place to get the network up and running again as quickly as possible. Many organisations, such as banks, have a disaster recovery plan which may mean relocating to a different location (if the building is no longer accessible). Failover a nd backups If there is a power cut, many networks have UPS (uninterrupted power supplies) which are large batteries with enough charge to keep the network going long enough to shut it down correctly. If a hard drive fails, there is usually a backup which can take the strain.Networks are often backed up at least daily and these backups are stored off-site or in a fire-proof safe so in the event of a disaster in the building, the data is still intact. Maintenance Sometimes data needs to be kept but is not accessed regularly. This data can be archived off onto tape to help free up space on the network. Acceptable Use It is important for the network to have an acceptable usage policy to provide users with guidelines about what they can and can’t do using it. For example, it would use up vital network bandwidth if some users decided to play a network game or download the latest torrent from the Internet. If users start file sharing copyrighted materials, like music, using the netw ork then there is a legal issue to consider as well. 40 The InternetYou need to be able to: (a) describe the nature of the Internet as a worldwide collection of computer networks (b) describe the hardware needed to connect to the Internet including modems, routers etc (c) explain the need for IP addressing of resources on the Internet and how this can be facilitated by the role of DNS servers (d) explain the importance of HTML and its derivatives as a standard for the creation of web pages (e) describe common file standards associated with the Internet such as JPG, GIF, PDF, MP3, MPEG (f) explain the importance of compressing files that are transmitted via the Internet (g) describe the differences between lossy and lossless compression. What happens when you type in a web address in your browser? When you enter a web address in your browser, it heads off via your modem to your ISP’s (Internet Service Provider) domain name servers (DNS).These computers store the IP address(es) for each website and directs your request to the relevant server hosting the webpage you want to view. The information is then sent back to your ISP and then back to your computer. Why HTML? HTML (HyperText Markup Language) provides a standard format which any computer with web browser can interpret and display the pages. It allowed the World Wide Web to get going as there was a universal standard that everyone could now use to share information. 41 Common file formats used on the Internet . html . jpg HTML Web page JPEG image Used to store webpages Used to store photos as can show up to 16. 7 million colours. Used for simple graphics and short animations – can show up to 256 colours.Used to store noneditable documents for viewing on the Internet using the free Adobe viewer software. Used to store music tracks. Compressed to make downloading faster. Used to store videos. Compressed to make downloading faster. Used for Adobe Flash files to add interaction and/or animations to websites. Used to store video files playable using free Apple viewer software. .gif Graphic Interchange format image .pdf Adobe Portable Document format .mp3 MP3 Music format .mpg MPEG video format .swf Shockwave Flash format .mov Apple Quicktime format Why compress on the Internet? The Internet can be slow at times, especially in it’s early days relying on early 56Kbps modems as opposed to the 3-4 Mbps average.Therefore if you could compress the files that were being sent on the Internet, then you sent smaller files, and smaller file sizes meant faster downloads. It also frees up the network and avoids clogging up the bandwidth. 42 Lossless versus Lossy Compression Lossless compression Compression used means the original file stays completely intact and unchanged. Used for text documents, data files and executable programs where it would not be desirable for parts to be lost. Used for multimedia files, i. e. sound, images, video. Lossy compression Compression which involves discarding parts of the file which won’t be noticed if they are not present.For example, it is possible to remove some data within an image and your brain fills in the gaps. Take a look at the images of the dog below: Source: wikipedia. org The image has more compression applied to it as you go from left to right. Even though the image on the right in heavily compressed, we can still see it is a dog. Our brain fills in the gaps. 43 Databases What is a database? A database is a persistent organised store of data which can be easily and quickly searched. They are most commonly used for Marketing, e. g. loyalty cards. Huge databases are searched for patterns in customer’s buying habits and then targeted coupons are mail shot to customers.The school has several databases to store everything from your behaviour logs and Brunels, to your address, date of birth and even how much money you have on your lunch card! Data handling software, such as Microsoft Access, allow users to: add tables, define fields and validation (create) add/edit/delete data (maintain) run queries to extract information from the database (interrogate) DBMS (Database Management System) Many large databases use a database management system (DBMS). This system separates the data stored from the data handling applications used to maintain and interrogate the database. Feature Concurrent usage Security Recovery & Backup Data integrity Why is this good? Allows multiple users to use the database at the same time Provides bility to allow/restrict data access to individuals or applications Provides backup solution and recovery tools to ensure data is not lost in event of failure Enforcing data integrity by ensuring data is consistent and adheres to the rules Relational databases A flat-file database is when all of the data and fields are stored in one table, e. g. an excel spreadsheet full of names and addresses – see below: 44 A relational database is when that data is separated i nto individual tables (entities) that are linked by a primary key (which appears in each table). Student Student ID First name Surname Class Class ID Student ID Teacher ID Teacher Teacher ID Name SubjectIn the example above, the STUDENT, CLASS and TEACHER are all tables (entities) in the database. The id is the unique piece of information (the primary key) that identifies each instance of a student, class or teacher. We couldn’t use First Name as the primary key in STUDENT as many people share the same first name – it isn’t unique enough! The advantage of separating the data into different entities is to avoid data redundancy – when the same data is stored in several places in the database. Let’s imagine if we stored the information above in a flat-file database (all in one table) – it would look something like this: Duplicated data Can you see the duplicated information?Not only does this use up space but it is easier to make a mistake (and lose data integrity) if we only update one of the records. E. g. if Miss Parsons gets married and her name changes to Mrs Smith then we need to make this change for every record in the database. If are using a relational database, because the Teacher’s name is stored in a separate table and linked to the rest of the entities, we only need to update it in the TEACHER table once. In the CLASS entity, both Teacher ID and Student ID are foreign keys (primary keys that when linked to another table become foreign keys in that table). Components of a relational database Tables Represents the entity in the database. Fields and primary keys are defined and data stored in the table. Create) Forms Provide a customisable user interface to add/edit and delete data (Maintain) Queries Allow data that meets specific criteria to be extracted and displayed (Interrogate) Reports Displays the results of queries in a customised format designed to be printed Querying a database 45 When interrogat ing a database, you need to specify the fields you wish to display and the criterion you will use to search. E. g. if you were searching for a car on a car supermarket website you might search using the make of the car you wanted: Make = â€Å"Ford† You could also use logical operators such as (NOT equal to), < (less than), > (greater than), = (greater than or equal to). E. g. Mileage

Reflective Log on Safeguarding

During your induction we discussed the importance of reflection, and ways in which this can be done. Below are some key questions you should consider after undertaking a training session You are expected to complete a reflective log following each of the workshops you attend. This will be used as evidence towards your qualification so the more detail you include the more criteria you will cover. Key questions to think about? Why did you choose to attend the workshop? Safeguarding is one of the most basic and the most important thing that effects the working of any setting.This course was an eye opener to me in various aspects and I Lana to attend more of these to touch up on what I have learnt. What did you hope to learn from attending the workshop? To gain insight into the guidelines, policies, procedures for safeguarding chiders and young people. To know how to respond to evidence of concerns where a child or young person may be abused. Did the workshop meet your expectations? Yes. It was very informative and touched on lots of Issues. Was there anything that you didn't understand or need further guidance with? Not much. In depth or more detailed will help. But this was Just a one day workshop.What have you learnt from attending the workshop? How to respond In case of abuse or harmful evidence surrounding children, The various policies , procedures and guidelines on safeguarding. Understood the importance of working In Ana environment where communication has to be very effective. And to work In partnership with various other organizations which regard to children safety. How have you cascaded your learning to your team? Yes. How has the workshop Impacted on your practice? I am more vigilant and I am more confident as I know what to do and what can be done. How has your learning benefited your setting?Being a volunteer I did not have much knowledge of basics. I am now more confident and I know I can rely on my team to support me whenever need arise.. Where wil l you go next? Do you need further Information/training? A regular touch up on the course would be beneficial. Please give examples wherever possible to support your reflections. I now know about the LESS. The context of mute agency working. The signs/ forms and effects of abuse. WHat to look out for. Indemnifying the delftware kinds of abuse psychological, emotional, physiochemical and financial. Reflective Log on Safeguarding By vaudevillian's Yes.It was very informative and touched on lots of issues. Was there anything that How to respond in case of abuse or harmful evidence surrounding children, The importance of working in Ana environment where communication has to be very effective. And to work in partnership with various other organizations which regard to How has the workshop impacted on your practice? You go next? Do you need further information/training? A regular touch up on the The context of mute agency working. The signs/ forms and effects of abuse. WHat to look out fo r. Indemnifying the different kinds of abuse psychological, emotional, physiochemical and financial.