Robinson Crusoe Essays (509 words) - English-language Films

Robinson Crusoe Robinson Crusoe, by Daniel Defoe, is a story about a man and his extraordinary travels throughout the world. In the beginning, Robinson Crusoe travels out to sea against the will of his father. He learns to regret this, though, as he becomes enslaved, and later shipwrecked. He became shipwrecked on an island where was the sole survivor. As a shipwrecked man, he had few possessions and had to use his surroundings to survive. He painstakingly constructed his needs and wants until, after twenty-six years he was finally able to leave the island. Although very exciting and adventurous, Robinson Crusoe is more than just a story about a man's adventure and struggle to survive, it depicts one man's quest for spiritual salvation. In the beginning of the book, Robinson Crusoe is not a devout Christian. He disobeyed his parents when he ran away to sea. He called upon God only in times of trouble. He rarely used God's name unless to swear, and in turn blasphemed it. Although he coped with the hardships of slavery and suffered its wickedness, he took a slave of his own after he escaped from his master. This behavior does not represent a devout Christian nor does it represent a person with high moral standards. Later in the book Crusoe described his attitude when he said, "I had no more sense of God or His judgments ....... than if I had been in the most prosperous condition of life." This shows the reader that Crusoe was virtually unaware of God's presence. Later in the book he becomes aware, and after becoming shipwrecked on the island, Robinson Crusoe asked God for his survival. He later realized that he should have actually thanked God for helping him survive the wreck and for helping him survive on the island. This action marks Crusoe's change from a person who is unaware of God into a person who believed that God has control of the Earth and that God directly affects every man's life. After living on the island a few years Crusoe craved something to read. He decided to read the bible because it was the only book on the Island. He found that the Bible had answers for many of his problems. He mentions the quote, "I will deliver thee" and viewed it applicable to his life. Although the previously mentioned events are examples of Crusoe's growing faith towards God, there is one event that marks his true spiritual salvation. When Crusoe cried, "Jesus, Thou Son of David, Jesus, Though exalted Prince and Saviour. Give me repentance!" the reader is informed that Crusoe has become a Christian and has accepted Jesus Christ as his Savior. Throughout the rest of the book there are many exciting adventures and battles, and even though Crusoe finds his way off the island he never lost touch with God and his teachings. He became wealthy and remained spiritually sound as he spread his wealth not only to the church, but also to the people that helped him throughout life. The book ended on a good note as he gave tools and provisions to the people left on the island to help them survive. This event marked the end of Robinson Crusoe's quest for spiritual salvation.

Overview of London Ambulance System (Las) Disaster, 1992 Essay Example

Overview of London Ambulance System (Las) Disaster, 1992 Essay Example Overview of London Ambulance System (Las) Disaster, 1992 Essay Overview of London Ambulance System (Las) Disaster, 1992 Essay The London Ambulance Service (LAS) is world’s largest free ambulance service covering an area of more than 600 square miles with a population of 7 million people. On any given day, LAS transported more than 5,000 patients and handled more than 2,000 telephone calls. LAS employed over 2,700 people, including an operational staff of roughly 2,000 people. (Cited http://bobpinchbeck. com/College/Work/Papers/DispatchingFailure. htm) In the mid-1980s, the LAS emergency despatch system was run completely manually. The details of a call, such as the location and type of incident, were noted on paper and sent to a central collection point where duplicate incidents will be eliminated. Call details were then given to an allocator who selected which vehicle and crew to send. The details were next passed to a dispatcher who contacted the ambulance driver by radio or phone. Problems arise when paper details are lost, they were not able to track incident and there are difficulties in tracing how the original call had been dealt with. In order to improve the quality of the service, they introduced a Computer Aided Dispatch (CAD) system in 1992. It was developed by two companies, Apricot Computers, a UK based hardware manufacturer, and System Options, a small UK software developer. CAD is a method of dispatching services assisted by computer. The idea of the CAD system is that people from the dispatch centre are able to view and understand the status of all the units being dispatched and provides tools and mechanisms for monitoring the dispatcher so calls can be handled more efficiently. The system consists of several modules that provide services at multiple levels in a dispatch centre and in the field of public safety. These services include the following; Call input, dispatching, status maintenance Handling incident details and locations Field unit status and tracking Call resolution and disposition It also include interfaces that permits the software to provide services to dispatchers, call takers and field personnel with respect to control and use of analogue radio and telephony equipment. (Cited www. erichmusick. com/writings/06/las_failure. html) The London Ambulance Service decided to put their new CAD system in to operation on October 26th, 1992. After a few hours into operation it became observable to the ambulance crews and control room staff that there is something wrong with the new system. The crisis was a high event in the UK news during that time, which claimed a number of patients have died as a result of the system. The following problems occurred within the CAD system when it was first in operation: Patient’s emergency calls that were accepted appeared to be getting lost in the system caused an increasing number of call duplications. Rise in number of calls led to the callers being held by the call-queuing system for up to 30 minutes before they were dealt with. At some point earlier calls were overwritten by newer emergency calls coming into the system, leaving a large number of unanswered calls which caused a number of exception messages. The ambulance allocation system failed to recognize certain roads. Staffs had to revert to using a map and telephone to deal with ambulance dispatches, which ultimately led to more delays. There was a communication failure between the ambulances and the system. Ambulance either arrived late, did not arrive at all or arrive two at the same time. (Cited www. comp. lancs. ac. uk/computing/resources/IanS/SE7/CaseStudies/LondonAmbulance/LASFailure. pdf)

World Applications Of Statistics ANOVA and Nonparametric Tests Essay

World Applications Of Statistics ANOVA and Nonparametric Tests - Essay Example The variance in the data may be within the realm of chance. However, there may be other factors that are affecting his sales. By analyzing a small amount of data among a few groups, a non-parametric test can show which factor is the cause of the variance. Inferences can be drawn from ANOVA from very small sample sizes and limited data. This makes it practical to use when the cost of data collection is a consideration. While larger samples will increase the power of the test, small samples can be measured by their degree of variance and further increase the power of the test if the variance is small. Another lesson learned was that the analysis of variance is so complex that it is impractical to perform on a calculator. There are many computer programs that calculate ANOVA such as Excel and SPSS. Today, this complex area of statistics can be performed on a limited budget with a minimum amount of computer software. The simulation demonstrated that meaningful information about a varianc e among groups can be tested with limited resources. The concept of using small sample sizes makes analyzing business data convenient for small-scale operations. The knowledge that it can be done with Excel makes it even more valuable, as I am moderately proficient at using it. Another key feature of ANOVA is that it can work with ordinal or interval data. This is especially useful when gathering data through a questionnaire. In addition, ANOVA is able to measure the interaction between multiple factors.

Genetics of Retroviruses Essay Example | Topics and Well Written Essays - 1000 words

Genetics of Retroviruses - Essay Example The core contains two identical copies of the single stranded RNA genome. The RNA molecules are complexed with reverse transcriptase and tRNA. Other viral proteins like integrase are also components of the virion particle. The outer envelope glycoprotein (SU), is the major antigen of the virus, and is responsible for receptor binding. The trans-membrane glycoprotein (TM), holds the SU protein in the envelope, and is responsible for membrane fusion â€Å"All retrovirus genomes consist of two molecules of RNA, which are s/s, (+)sense and have 5 cap and 3 poly-(A) (equivalent to mRNA). These vary in size from ~8-11kb. Retrovirus genomes have 4 unique features: These two molecules are physically linked as a dimer by hydrogen bonds (co-sediment). In addition, there is a 3rd type of nucleic acid present in all particles, a specific type of tRNA (usually trp, pro or lys) - required for replication.† Gene order in all retroviruses is invariant: 5 - gag - pol - env - 3. The gag (group-specific antigen, core protein) gene encodes proteins that make up the nucleocapsid of the virus as well as a matrix layer, the two of which surround the RNA. The pol gene (RNA-dependent DNA polymerase) encodes three proteins, reverse transcriptase, which copies the RNA into DNA, integrase, which integrates the DNA into the host chromosome and protease, a protein that cleaves the Gag-Pol polyprotein into smaller protein products. The env gene encodes the envelope glycoproteins. â€Å"Some retroviruses have incorporated viral oncogene sequences.†( www.bookrags.com) The genomes of complex retroviruses, such as human T-cell lymphotropic virus (HTLV) cont ain additional genes (e.g., tax and rex) for regulatory proteins. R Region: A short (18-250nt) sequence which forms a direct repeat at the both ends of the genome, which is therefore terminally redundant.U5: A unique, non-coding region of 75-250nt

NORMALIZATION AND SQL DDL STATEMENTS Essay Example | Topics and Well Written Essays - 500 words

NORMALIZATION AND SQL DDL STATEMENTS - Essay Example Atomicity ensures that no incomplete transactions are ever executed by the system which ensures the state of data always remains stable despite any hardware/software failures. Consistency ensures that only those transactions will execute that do not violate any of the database consistency rules which ensures data remains valid. Isolation ensures uninterrupted single transaction processing e.g. the concurrent transaction requests are handled serially i.e. one transaction at a time. Durability ensures that transactions are logged and therefore transactions can be rolled back at any time. Database normalization is a set of guidelines that helps in organizing data efficiently which improves the overall performance of a DBMS. It helps remove data redundancy (does not allow duplicate data storage in multiple tables) which in turn reduces the space consumed by database. Furthermore, it improves data consistency by allowing only sensible and logical data dependencies between tables (e.g. a table stores only data that is related). There are five normal forms of database; 1NF, 2NF, 3NF, BCNF and 4NF. Mostly, normalization till the third form is enough for most database system applications. 1NF helps eliminate duplicate column from a table and identifies unique column(s) i.e. through primary key. 2NF separates data subsets into separate tables forming foreign keys. And 3NF ensures all columns in a table are dependent only on the primary key. The exercise helped in understanding the concept of ACID model and offered a hands-on approach to designing and optimizing a database design. It helped in practicing the application of the most widely used normalization guidelines on a previously formed database model. Furthermore, it also helped practice the DDL statements involved in the actual creation of a database application in

Calcium In Contraction Of The Heart

Calcium In Contraction Of The Heart In cardiac muscle, excitation-contraction coupling is mediated by calcium-induced calcium release from the sarcoplasmic reticulum through ryanodine receptors that are activated by calcium entry through L-type calcium channels on the sarcolemmal membrane. Although Ca2+ induced Ca2+ release triggered by the L-typed calcium current is the primary pathway for triggering Ca2+ from the sarcoplasmic reticulum, there are many other mechanisms that can also activate Ca2 + release from the sarcoplasmic reticulum such as Calcium induced calcium release (CICR) induced by T-typed calcium current, CICR triggered by calcium influx through Na+/Ca2+ exchange, and CICR mediated by calcium through tetrodotoxin (TTX)-sensitive Ca2+ current (ICa,TTX). As calcium is an important second messenger which is essential in regulating cardiac electrical activity as well as being the main activator of the myofilaments to which cause cardiac contraction. Mishandling of calcium is thought to lead many pathophysiological conditions. Knowledge of the mechanisms involved in regulating intracellular calcium and therefore contraction of the heart, may help to prevent and/or treat pathological conditions such as cardiac hypertrophy, arrhythmias or heart failure by using therapeutic agents targeted at modulating intracellular calcium. ACKNOWLEDGEMENT Firstly, I would like to show my deepest gratitude to my supervisor, Dr. Munir Hussain, who is a Senior Lecturer in Biomedical Sciences in University of Bradford for his innovative, supportive, expert, professional, kind and careful supervision, constant guidance and, academic support. Without his advice and guidance, my dissertation will not be finished with great success. I would also like to show my sincere thank to all the lecturers from Management Development Institute of Singapore (MDIS) and teachers in my student life for letting me gain strong knowledge in biomedical science field and essential knowledge to be in this stage and my student coordinator and stuffs from Student Service Unit (SSU) for their kind arrangement, support, encouragement and care. I would like to thank to all my friends who supported me both physically and mentally during my preparation for the dissertation. Last but not least, I would like to convey my special deep thank to my parents who always give me tender love, care and all supports all the time. Without their guidance, support and love, nothing can be achieved by me. LIST OF FIGURES Figure 1: Calcium transport in ventricular myocytes 3 Figure 2: Six possible mechanism of cardiac excitation-contraction coupling 9 LIST OF ABBREVIATIONS LTCC = L-type calcium channels CICR = Calcium induced calcium release ECC = Excitation-contraction coupling NCX = Sodium-Calcium Exchange SR = Sarcoplasmic Recticulum ICa = Calcium current ICa,T = T-type calcium current ICa,L = L-type calcium current ICa,TTX = Tetrodotoxin-sensitive calcium current RyRs = Ryanodine Receptor [Ca2+]i = Intracellular calcium concentration [Ca2+]Tot = Total concentration of Calcium PKA = Protein Kinase A LVH = Left Ventricular Hypertrophy HOCM = Hypertrophic obstructive cardiomyopathy Introduction In heart muscle cell, the depolarization of action potential is due to the entering of Na+ ions via voltage gated Na+ channels and it is called fast inward current. The immediate repolarization is not possible due to rapidly inactivation of Na+ channel and initial depolarization allow the entering of calcium through voltage-grated Ca2+ channels and it is called second or the slow inward current. The rate of sodium channels inactivation is more rapid than that of calcium channels so that Ca2+ enters into the cell providing the membrane potential to close to 0mV for some part of action potential of heart muscle (Reuter, 1984). Excitation-contraction coupling (ECC) is the process in which an action potential triggers a myocyte to contract. In excitable muscle cells, the excitation signal causes rapid depolarization that produces the physiological response of contraction. Calcium is a ubiquitous second messenger, important in both, regulating the electrical activity of the heart as well as stimulating the myofilaments directly to cause contraction (Bers, 2001). In mammalian cardiac myocytes, the process of ECC is mediated by Ca2+ influx from the extracellular space that triggers Ca2+ Calcium induced Calcium release (CICR) from the sarcoplasmic reticulum (SR) (Bers, 1991; Stern Lakatta, 1992). When action potential reaches the myocyte, causing it to undergo depolarization, which causes calcium ions to enter the cell through L type calcium channel located on the sarcolemma and thereby trigger calcium release from the SR. Calcium influx and the intracellular calcium concentration trigger the contraction of heart due to binding of Ca2+ to cardiac muscle fiber protein, troponin C. For activation of SR calcium release, the L-type calcium current is the most widely accepted mechanism thought to be responsible for CICR. However, SR calcium release can also be triggered by calcium influx through sodium-calcium exchange, calcium influx via T-type Ca2+ current or through tetrodotoxin-sensitive Ca2+ current, or Inositol (1,4,5)-triphosphate (but not so much in cardiac muscle). Declining of calcium level in the cells cause the detachment of calcium from myofilament and resulting in relaxation of the heart. There are four main pathways for Ca2+ transport out of the cytosol including SR Ca2+ ATPase, sarcolemmal Ca2+-ATPase or mitochondrial Ca2+ uniport and sarcolemmal Na+/Ca2+ exchange. (Bers, 2002). Since CICR is a positive-feedback mechanism, it has to be terminated which is essential for diastolic refilling of the heart. There are three main pathways for termination of calcium release such as local depletion of SR Ca2+, Ryanodine ( RyR) inactivation (or adaptation), and stochastic attrition. (Lukyanenko et al., 1998). Mutation in calcium channels can lead to life-threatening arrhythmias. The improper contractile function and abnormal heart rate associated with cardiac hypertrophy and heart failure is due to the mishandling of calcium in heart muscle cell (Pogwizd et al., 2001). In this dissertation, here I discuss about the key mechanism of how Ca2+ transport in cardiac ventricular myocytes. Moreover, I also discuss about how they are modulated and regulated as well as how they interact specifically. In addition, by knowing the subcellular mechanism of E-C coupling, here I discuss about how calcium is altering and getting mutated so as to cause cardiovascular diseases. The imp ortant molecular signaling pathways in contraction of heart will also be addressed. Figure 1. Calcium transport in ventricular myocytes. (Adapted from Bers, 2002) The figure shows the time course of an action potential, Ca2+ transient and contraction in rat ventricular myocytes, NCX, and other protein involved in contraction. Calcium channels in contraction of the heart In cardiac muscle, calcium has a role for the ability to make the cardiac cell to contract. There are five types of calcium channels; L, T, N, P/Q and R types. Among them, L-type and T-type calcium channels are two major types of calcium channels in the cells of cardiac tissues (Bean, 1989). L-type Ca2+ channels have many subunits in the heart such as ÃŽÂ ±1, ÃŽÂ ±2, ÃŽÂ ´ and ÃŽÂ ² subunits. The ÃŽÂ ±1 subunit is the dihydropyridine (DHP) receptors which are important for calcium entry into the cells (Liu et al., 2000). L-type calcium channels (long-lasting) can activates at more positive membrane potential (Em), at greater than -40mV and generate peak inward current at 0mV and slowly inactivated, and is sensitive to dihydropyridines (Tsien et al., 1987). Thus, the L-type Ca2+ channels are the majority of calcium channels responsible for entering of Ca2+ into the cardiac cell during phase 2 (plateau phase) of the action potential. On the other hand, T-type (tiny or tr ansient) Ca2+ channels cause the activation and inactivation at more negative membrane potential (Em) and dihydropyridines cannot block effectively (Nowycky et al., 1985). However T-type Ca2+ channels have faster kinetics than compared to L-type Ca2+ channels. During development and hypertrophy, T type calcium current is more prominent and the T-type current is typically small or absent in ventricular myocytes. The entering of Ca2+ into the cell by passing through I Ca,T is only responsible for smaller amount of Ca2+ than that passing through ICa,L. In most ventricular myocytes, T-type calcium current is almost negligible. It shows that the releasing and refilling is mainly provided by Ica,L. The amount of L-type calcium current and T-type calcium current is variable among cardiac myocytes. L-types calcium current is present in all cardiac myocytes whereas T-type calcium current have larger component in the canine Purkinje fiber (Zhou, 1998). Depolarization during the action potent ial causes activation of calcium current. During an action potential, the amount of calcium entry is limited by calcium dependent inactivation at the cytosolic side. L-type calcium channel is located at the sarcolemmal-SR junction where ryanodine receptors exist (Scriven et al., 2000). There is a negative feedback effect on Ca2+ influx and SR Ca2+ release during excitation-contraction mechanism. When there is increased Ca2+ influx or release, further release of Ca2+ is turned off. There are many isoforms of ryanodine receptors, (RyR1, RyR2, RyR3), among them, RYR2 is the cardiac isoform. RyR2 mediated release of Ca2+ from sarcoplasmic recticulum is an important step in cardiac E-C coupling in the heart. RyR2 is a Ca2+-gated channel (Nabauer et al, 1989). RyR2 is activated by Ca2+ influx through L-type Ca2+ channel or dihydropyridine receptor (Adachi-Akahane, 1996). Cytosolic Ca2+ is increased by the RyR2 opening and bind with contractile protein (troponin C) that trigger the contraction of heart. In ventricular myocytes, there are much more ryanodine receptors than dihydropyridine receptors. Therefore, four or ten RyRs can be associated with a single L-type Ca2+ channel (Bers et al., 1991). Defection in excitation- contraction coupling can occur due to either if RyRs channels sensitivity is altered for activation/inactivation or if the SR Ca2+ is depleted. There has been demonstrated in animal model of cardiomyopathy (Gomez et al, 1997). [Ca2+]i and Ca2+sparks [Ca2+]i and total [Ca2+] determine the development of contraction which produces both isometric force and rapid shortening (Moss, 2001). The strength of cardiac contraction can be changed by two ways: (1) by changing the extent and amplitude of the Ca2+ transient, (2) by altering the myofilament sensitivity to Ca2+. The sensitivity of myofilament calcium is increased by contracting the myofilament when the heart fills with blood resulting the contraction to be stronger. Caffeine and certain inotropic agents can enhance the myofilament sensitivity whereas the increased concentrations of phosphate and Mg2+ and acidosis reduce myofilament Ca2+ sensitivity. Ca2+ sparks is the process of spontaneous release of SR Ca2+ and it was described by using confocal fluorescence microscopy (Cheng et al., 1993). The release of SR Ca2+ via single L-type Ca2+ channel or RyRs openings generates Ca2+ sparks (Song et al., 1997). Ca2+ spark is activated by the Ca2+ entery through ICa (Cannell et al, 1995) . Ca2+ spark is triggered by the opening of single channel opening. There have been reported that spark probability can be depend on binding of two Ca2+ ions to the RyR (Santana et al., 1996). Thus, local cytosolic [Ca2+]i is important in the frequency of Ca2+ sparks and SR Ca2+ release. Moreover, the frequency of Ca2+ spark depends on the SR Ca2+ load (Cheng et al, 1993). When there is increased SR Ca2+ load, this may lead to increase the amplitude of Ca2+ spark. Therefore SR Ca2+ load is an important factor for Ca2+ release from SR. Role of Sarcoplamic Recticulum ECC and intracellular Ca2+ homeostasis are primarily regulated by sarcoplasmic recticulum (Bers, 1991). Once stimulation, calcium enters the cell, thereby stimulating the release of larger amount of calcium from SR resulting in activation of contractile protein and contraction of the heart. During cardiac relaxation, Ca2+ is taken up by SR by SR Ca2+ ATPase pump and Na+/Ca2+ exchange pump. The key SR Ca2+ release channel involved in cardiac contraction is RyRs and RyR2 is the cardiac isoform. The amount and fraction of Ca2+ release that depends on the level of SR Ca2+ load can release for a given ICa trigger (Shannon et al., 2000). Sensitivity of RyRs receptor to [Ca2+]i at high load of SR Ca2+ leads to increase spontaneous SR Ca2+ release. On the other hand, decrease in SR Ca2+ release (which is induced by ICa ) can be due to low SR[Ca2+] content. The lower the amount of the SR Ca2+ release, the more amount of Ca2+ enter the cells through Na+/Ca2+ exchange. When there is low concent ration in SR Ca2+, Ca2+ release from SR is turned off during E-C coupling. Furthermore, SR Ca2+ content depends on the heart rate and duration of action potential. Ca2+ concentration release from SR can be increased by more mount of Ca2+ enter into the cell, by decreasing Ca2+ efflux or increasing SR Ca2+ uptake. Phospholamben, an endogenous inhibitor of SR Ca2+ ATPase, is triggered by activation of cAMP-dependent or calmodulin-dependent protein kinase. When this phospholamben becomes phosphorylated, Ca2+ uptake by SR is increased and allows faster cardiac relaxation and declining of [Ca2+]i. Targeted knockout of phospholamben leads to hyperdynamic hearts with negative effects (Brittsan Kranias, 2000). Interestingly, lower SR Ca2+ uptake, reduced SR Ca2+ATPase gene and protein expression were seen in failing human heart (Pieske et al., 1995). On the other hand, there has been demonstrated that increased gene expression of sarcolemmal Na+/Ca2+ exchanger was seen in human failing hea rt (Reinecke et al., 1996). Regulation of Calcium current Ica can be variable physiologically and pharmacologically. During physiological sympathetic stimulation of heart, catecholamine stimulate beta-adrenegic receptors, which improve the force of contraction (inotropic effects) and relaxation (lusitorpic effects) and declining of [Ca2+]i. In addition, stimulation of ÃŽÂ ²-adrenergic receptor stimulates a GTP-binding protein that accelerates adenylyl cyclase for the cAMP production. cAMP activates PKA, which phospharylates severe protein such as phospholamban, RyR, L-types Ca2+ channels, myocin binding protein C and troponin I ( which are related to ECC). Activation and phosphorylation of L-type Ca2+ channels will cause Ca2+ release from SR causing contraction of the heart. Phosphorylation of troponin I and phospholamban stimulate the reuptake of Ca2+ release from SR and Ca2+ is dissociated from the myofilament and develops to cardiac relaxation (Lusitropic effect). The inotrophic effect of PKA (protein kinase A) activation is triggered by the combination greater availability of SR Ca2+ and increased calcium current. Open probability of RyR channels can also be modulated by protein kinase A. RyRs receptors are hyperphosphorylated in heart failure causing a diastolic leak of SR Ca2+. However, whether PKA-dependent phosphorylation will alter during excitation-contraction or not still remain controversial. Moreover, phosphorylation of L-type Ca2+ channels, phospholamban and troponin I are paralleled with activation of ß1-adrenergic receptors in ventricular myocytes that produce inotrophic and lusitropic effects. On the other hand, ß2-adrenergic receptors activation can give more restricted to the enhancement of ICa (Kushel et al., 1999). cAMP production can also be stimulated by the G-protein-coupled receptors such as prostaglandin E and histamine that will lead to little or no effect of inotropic effects (Vila Petroff et al, 2001). Other receptors will also regulate the signaling pathway. For instance, M2-musc arinic receptors activation can decrease cAMP and activation of PKA thereby decreasing Ca2+ entry and release. In addition, this pathway also enhances repolarization. The pharmacological effects of L-type Ca2+ channels are in which calcium sensitivity to dihydropyridines (nephedipine, amlodipine, nitrendine, nimodipine, nisoldipine). Ica is inhibited by most of DHPs and they are called Ca2+-channel blockers. In DHPs, there are two other types of specific L-type Ca2+ channel blockers (1) phenyalkylamines (eg. verapamil, D600) and (2) benzothiazepines (eg, diltiazem), and those agents can act together directly with the Ca2+ channel (Glossmann et al., 1985). Verapamil can inhibit the calcium channel in the open state but it require depolarization pulse) and this is called use dependent. The neutral ligands such as nitrendipine and nisoldipine inhibit ICa depend on the calcium channel whether they are in the opening state or inactivated state , and does not require depolarization pulse as they are voltage dependent than use dependent. Figure 2. Six possible mechanism of cardiac excitation-contraction coupling. (Adapted from Bers, 1999) The figure shows Ca2+ influx via ICa,L, Ca2+ influx via ICa,T,Ca2+influx through NCX, Ca2+ influx via IP3 ,Ca2+ influx via ICa,TTX and depolarization dependent Ca2+ influx. Calcium induced calcium release during E-C coupling There have been demonstrated that CICR in skinned ventricular myocytes (Fabiato and Fabiato, 1975). There was been proved that main pathway of E-C coupling in cardiac myocytes is by Ca entry through L-type Ca2+ channels and triggers SR Ca2+ release (Bers, 1991). When calcium channel becomes deactivates, before calcium channels close, calcium transient is induced by a large and short-lived ICa causing contraction. Moreover, Ca2+ channel activation in the absence of Ca2+ influx also cannot induce calcium release from the SR (Nabauer et al., 1989). There is supported that ICa activate SR Ca2+ release channel when there is a high concentration of Ca2+ buffer in the cell (Adachi-Akahane et al., 1996). Ca2+ release from SR is most commonly activated by L-type Ca2+ channels and this pathway is called Ca2+ induced Ca2+ release (CICR). There has been little doubt that E-C coupling occurs physiologically but there are other mechanisms which can exit in parallel and give rise to the functional effects. Ca influx via ICa,T In ventricular myocytes, T-type calcium channels is relatively small or absent but it is more prominent in the development and hypertrophy of the heart. Because of T-type calcium current is relatively small and rapidly inactivated, the total amount of calcium influx through T-type calcium current is absolutely small compared to calcium influx via ICa,L (Zhou, 1998). Moreover, T-type calcium current is negligible in most of ventricular myocytes. T-type Ca2+channels are not located at the SR junction, therefore the effectiveness of ICa,T as a trigger for Ca2+ release from SR is not effective as ICa,L. Furthermore, SR Ca2+ release by ICa,T is delayed on onset and slower than ICa,L. However, it can be significant in other cardiac cells such as some atrial cells and Purkinje fibers (Zhou and January, 1998). Since T-type calcium channel is non-functional in most of the myocytes of ventricle, it does not play a major role for ECC although it may function like ICa,L. So, ICa,T only plays a m inor role in triggering Ca2+ release from SR during action potential. Ca influx via Na+/Ca2+ exchange Although L-type Ca2+ current is a major role of CICR in contraction of the heart, some argued that the L-type Ca2+ channels could not be the only way to trigger the calcium release from SR. There is an alternative trigger of calcium release in mammalian cardiac myocytes (Chunlei Han et al., 2002). The result of Ca2+ release by Na+/Ca2+ exchanger has been proved by examination on rats (Wasserstorm and Vites, 1996), rabbit (Litwin et al., 1998) and guinea pig (Sipida et al., 1997). Immunofluorescence labeling shows that the exchanger current is present in the cardiac T-tubules system (Scriven et al, 2000). There are two ways of triggering Ca2+ release from SR by Na+/ Ca2+ exchanger. The first mechanism is Na+ current by increasing local [Na+]sm, increasing Ca2+ entry through Na+/Ca2+ exchanger and causing SR Ca2+ release (Levesque et al.,1994 ). The second one is that depolarization directly stimulates outward INa/Ca and Ca2+ release and contraction when L-type Ca2+ channel become bloc ked or at high positive Em (Levi et al.,1994 and Litwin et al.,1998 ). Increased intracellular sodium stimulate the Na+/Ca+ exchanger (Evans and Cannell, 1997 ) and, if INa is low ([Na+]i=10nM) or lower, the reverse current of the Na+/Ca2+ exchange could trigger Ca2+ release account for 25%. When [Na+]i=30nM, the contribution of Na+/Ca2+ exchanger increase up to 100%. Additionally, the exchanger current is more dependent on the temperature and changes in the intracellular sodium and calcium concentrations than compared to L-type calcium current. Furthermore, these changes are larger in the microdomain or subspace (interaction between RyR receptors and L-type Ca2+ channels occurs) than compared to the rest of the cytoplasm (Vornanen et al., 1994). Although LTCC are faster than the exchanger current in triggering of Ca2+ release from SR, Ca2+ entry through the exchanger into the subspace is faster in beginning than L-type Ca2+ current when there is action potential stimulations becaus e the action potentials upstroke and sodium (inward) current is associated with rapid increase in [Na+]i. Therefore, any physiological stimulation or medication that alters the intracellular sodium becomes the regulator of calcium release from sarcoplasmic reticulum. Stimulation via hormone, such as activation of endothelin-1 (ET-1) receptor (Alvarez et al., 1999), and increasing frequency of action potential (Simor et al., 1997) will increase the intracellular sodium concentration, causing calcium release triggering via the Na+/Ca2+ exchanger by opposing to via the L-type calcium current. Ca2+ release from SR is slower via Ca2+ influx through Na+/Ca2+ exchanger than through L-type calcium channel (Spido et al., 1997) . Ca influx via TTX sensitive-Na channels Aggarwal and co-worker reported voltage-gated, calcium conducting sodium channel, (ICa,TTX), calcium entry via tetrodotoxin-sentive Na+ channels can also mediates CICR. This channel activates at membrane potential of -60mV and has faster kinetics than L-type Ca2+ channels. It can alter selectivity of cardiac Na+ channels triggers by either activation of agonist effects ÃŽÂ ²-adrenergic receptor or cardioactive steroids or cardiac glycosides, resulting Na+ channel prefer Ca2+ than Na channels and it is called slip mode or altered selectivity mode. The tetrodotoxin-sensitive Ca2+ influx can also trigger the SR Ca2+ release. The inotrophic effects of cardiac glycosides and ÃŽÂ ²-adrenergic agonists could be a novel mechanism. These effects could be triggered by SR Ca2+-pump activity and increased ICa or by Na+/K+ ATPase inhibition and also decreased Ca2+ efflux through Na+/Ca2+ exchange for cardiotonic glycosides (Borgatta et al., 1991). Moreover, one study in rat ventricular myoc ytes reported that Na+ current is activated by the phyosphoryation by protein kinase A or by the cardiotonic steroids. (slip mode conductance) (Santana, 1998). In addition, modified Na+currents conduct ICa,TTX which in turn triggers CICR. The relation between slip mode conductance and ICa,TTX is still controversial (Nuss, 1999). On the other hand, another study demonstrarted that Ca2+ current due to ICa,TTX or slip mode conductance is not related and identical. The reason is that the presence of cardiac steroids or activation of PKA is not a requirement for the detection of ICa(TTX). A small fraction of Na + currents can conduct ICa(TTX) even without phosphorylation of PKA (Nuss, 1999). Furthermore, TTX sensitive-Na+ channels cannot be inhibited by the blockers of T-type or L-type Ca2+ channels. Recently, one of studies showed that ICa(TTX) and T-type Ca2+channel coexit in guinea pig venricular myocytes because 10 mM mibefradil could block both ICa(TTX) and T-type Ca2+current (Heuba ch, 2000). Although this current is not the major current for triggering the CICR, its possible functional roles are important in normal heart cells such as promoting the sodium current activation and modulating rhythmicity of the heart. Ca influx via IP3 pathway Inositol (1, 4, 5) triphosphate could trigger Ca2+ release from SR and endoplamic reticulum in different cell types, they are called IP3 receptors. In ventricular myocytes, the major form of InsP3 is isoform 2 (Lipp et al., 2000). There are more InP3 receptors in atrial cells in ventricular myoctyes. Stimulation of IP3 signal transduction pathway can trigger the release of Ca2+ from SR via IP3 receptors which is located on SR. Even high concentration of InP3 in cardiac myocytes could trigger Ca2+ release from the SR, the extent of Ca2+ release from the SR are so much lower than CICR triggered by LTCC. Moreover, action potential cannot stimulate the InP3 production (Kentish et al., 1990). The production of InP3 contractile force is increased by cardiac alpha-adrenergic and muscarinic agonists (Poggioli et al., 1986). In addition, InP3 pathway only plays a very little minor role in cardiac EC coupling. To conclude for triggering Ca2+ release from SR, CICR in cardiac contraction is mai nly through L-type Ca2+channel.Other mechanisms that mentioned above show minor role in SR calcium release. Cardiac relaxation During an action potential, calcium entry into the cell is slow at the end of phase 2 and there is lowering of the cytosolic calcium concentration because calcium is taken back by the SR and removing of calcium from the troponin C and finally initial sarcomere length is restored. For relaxation and cardiac ventricular filling, Ca2+ have be removed from the cytosol to lower [Ca2+]i , causing relaxation. Cardiac relaxation to occur, Ca2+ must be dissociate from troponin C and it requires Ca2+ transport out of the cytosol primarily by four main pathways involving, sarcolemmal Na+/Ca2+ exchange, SR Ca2+-ATPase, sarcolemmal Ca2+-ATPase or mitochondrial Ca2+ uniport. There are selective inhibition for each transporter during cardiac myocyte relaxation and [Ca2+]i decline (Puglisi et al., 1996). SR Ca2+ uptake can be prevented by either thapsigargin or caffeine, complete removal of extracellular Na+ and Ca2+ can prevent sodium calcium exchange. Either carboxyeosin or elevated [Ca2+]i inhibi t sarcolemmel Ca2+-ATPase, and mitochondrial Ca2+ uptake can be inhibited by rapid dissipation of the electrochemical driving force for SR Ca2+ uptake by using protonophore FCCP. In rabbit ventricular myocytes, 70% of the activated Ca2+ removed by the SR Ca2+-ATPase from the cytosol, whereas 28% was removed by NCX, only 1% for sarcolemmal Ca2+-ATPase as well as mitochondrial Ca2+ uniporter remove 1% of calcium from SR ( the last two pathways are called slow systems). In rat ventricular myocytes, SR Ca2+-ATPase activity is higher due to more pump molecules in unit cell volume (Hove-Madsen Bers, 1993). On the other hand, Ca2+ removal via Na+/Ca2+ exchange is lower, 92% with SR Ca2+-ATPase, 7% with NCX, the slow systems with 1 % respectively. In mouse ventricular myocytes, the uptake mechanism is quite similar to rat, (Li et al., 1998) while the mechanisms of Ca2+ fluxes in human ventricular myocytes, guinea pig and ferret are more similar to rabbit myocytes (Pieske et al., 1999). In contraction and relaxation of myocytes, the amount of calcium removed from the cell during relaxation must be the same as the amount of calcium entry during contraction in each heart beat, if not, the cell may gain or lose the calcium. Defects in Ca2+ removal also can cause impair relaxation Termination of calcium release Although CICR is a positive-feedback mechanism, termination or turning off of the Ca2+is important for diastolic refilling of the heart. There are three major ways for terminations of Ca2+release include local SR depletion, RyR inactivation or adaptation and stochastic attriction (Sham et al.,1998; Lukyanenko Gyorke,1998). Stochastic attriction means L-type Ca2+ channels and all RyRs are closed simultaneously, then local [Ca2+]i will drop quickly to the sub-threshold level and disturbing the release from SR . However, this is only used for 1DHPR and 1-2 RyRs whereas they all will not close at once for other types of channels. In addition, local depletion of SR Ca2+ also may terminate SR Ca2+ but it cannot completely turn-off of release, because very long lasting Ca2+ sparks are found that will not decline with time (Satoh Bers, 1997). However other regions of SR can also limit local SR Ca2+ depletion. During a global Ca2+ transient, the whole SR Ca2+ declines. During a relaxation, SR Ca2+ depletion could lead to the turning -off global SR Ca2+ release. There are two types of RyR inactivation both of which depend on [ Ca2+ ]i .One of them is absorbing inactivation ( for example like Na+ channels), in which the ryanodine receptor cannot reopen until it recovers (Sham et al., 1998; Lukyanenko Gyorke, 1998). The another one is called RyR adaptation in which ryanodine after activation leads to a reduced open probability, but it can be reactivated by higher [Ca2+]i (Valdivia et al.,1995). RyRs inactivation could be important in reducing SR Ca2+ release events between each heart beats. To summarize, Ca2+ release during ECC is terminated mainly by a local RyRs inactivation and partial SR luminal Ca2+ depletion which leads to reduce RyR openings and variant of stochastic attrition also contributes. Role of calcium channels in cardiac hypertrophy, heart failure and arrhythmia Intracellular calcium is the major regulator of cardiac contraction. Therefore, altered cardiomyocyte regulation is important in arrhythmogenesis, cardiac mechanical dysfunction and cardiac hypertrophy associated with heart failure. Alteration in signal transduction pathways can also lead to loss of inotropic effects in heart failure. Defects in ECC have been reported in animal models of cardiomyopathy (Gomez et al., 1997). There is no E-C coupling depression was seen in pressure overload of cardiac hypertrophy with less sign of heart failure. (Rios et al., 1992). Cardiac hypertrophy is the enlargement and thickening of the heart muscle resulting in decreasing size of the chamber of the heart. Cardiac hypertrophy is the main cause of cardiac morbidity and mortality in cardiovascular system. It is associated with heart failure without myocardial infarction. Cardiac hypertrophy is associated with significant changes in myocardial contraction. These contractile dysfunctions are followed by changing in the whole-cell intracellular calcium transient. The pathogenesis and etiology of cardiac hypertrophy and heart failure related with the role of Ca2+ channels still remains controversial. of ÃŽÂ ² subunits of L-type Ca2+ channels (LTCCÃŽÂ ²) enhances the probability of channels opening as well as also favours the trafficking of the Ca2+ channels to the surface membrane leading to increase calcium current (Chen Y.H, 2004). Interestingly, there has been reported upregulation of LTCCÃŽÂ ² in failing human cardiomyocytes (Hullin et al, 2003). In aortic banding, L-type Ca2+ channels concentration is remain unchange in rats myocytes with hypertrophy ( Scamps et al.,1990), cats with pulmonary artery banding (Kleinman, 1988) cardiomyopathy in Syrian hamsters (Sen, 1994) ,and ventricular

All Quiet On The Western Front :: essays research papers

All Quiet on the Western Front, directed by Delbert Mann, is based on the novel written by Erich Maria Remarque. It tells the story of a German schoolboy, Paul Baumer, and a group of his classmates, who journey from fantasies of heroic glory to the real horror of actual soldiering. Their journey is a coming of age tale that centers on the consternation of war and emphasizes the moral, spiritual, emotional, and physical deterioration suffered by the young soldiers. Paul Baumer is a 19-year-old volunteer to the German army during World War I. He and his classmates charge fresh out of high school into military service, hounded by the nationalist ranting of a feverish schoolmaster, Kantorek. Though not all of them want to enlist, they do so in order to save face. Their first stop is boot camp, where life is still laughter and games. â€Å"Where are all the medals?† asks one. â€Å"Just wait a month and I’ll have them,† comes the boisterous response. This is their last vestige of boyhood. War slowly begins to strip away the ideals these boy-men once cherished. Their respect for authority is torn away by their disillusionment with their schoolteacher, Kantorek who pushed them to join. This is followed by their brief encounter with Corporal Himmelstoss at boot camp. The contemptible tactics that their superior officer Himmelstoss perpetrates in the name of discipline finally shatters their respect for authority. As the boys, fresh from boot camp, march toward the front for the first time, each one looks over his shoulder at the departing transport truck. They realize that they have now cast aside their lives as schoolboys and they feel the numbing reality of their uncertain futures. After their first two days of fighting, they return to their bunker, where they find neither safety nor comfort. A grizzled veteran, Kat, suggests these ‘fresh-faced boys’ should return to the classroom. The war steals their spiritual belief in the sanctity of human life with every man that they kill. This is best illustrated by Paul’s journey from anguish to rationalization of the killing of Gerard Duval; the printer turned enemy who leaps into the shell-hole already occupied by Paul. Paul struggles with the concept of killing a â€Å"brother†, not the enemy. He weeps despondently as war destroys his emotional being. War destroys Paul and his friends. Those who physically survive the bombing, the bullets and bayonets are annihilated by physical attacks on their sanity.

Factors Affecting Climate

Factors Affecting Climate There are many different factors that affect climate around the world. The most important factors are:- †¢Distance From The Sea †¢Ocean Currents †¢Direction of Prevailing Winds †¢Relief †¢Proximity To The Equator †¢The El Nino Phenomenon †¢Recently, it has been accepted that human activity is also affecting climate. Distance From The Sea (Continentality) The sea affects the climate of a place. Coastal areas are cooler and wetter than inland areas. Clouds form when warm air from inland areas meets cool air from the sea. The centre of continents are subject to a large range of temperatures.In the summer, temperatures can bevery hot and dry as moisture from the sea evaporates before it reaches the centre of the continent. Ocean Currents The Ocean Currents of the World http://www. itl. net cean currents can increase or reduce temperatures. The diagram to the left shows the ocean currents of the world. The main ocean current tha t affects the UK is the Gulf Stream. Can you see where the gulf stream is? The Gulf Stream is a warm ocean current in the North Atlantic flowing from the Gulf of Mexico, northeast along the U. S coast, and from there to the British Isles.The Gulf of Mexico has higher air temperatures than Britain as it's closer to the equator. This means that the air coming from the Gulf of Mexico to Britain is also warm. However, the air is also quite moist as it travels over the Atlantic ocean. This is one reason why Britain often receives wet weather. The Gulf Stream keeps the west coast of Europe free from ice in the winter and, in the summer warmer than other places of a similar latitude. The chart below was the first chart drawn of the Gulf Stream. It was drawn by Benjamin Franklin in 1770.The Gulf Stream – As Drawn By Benjamin Franklin http://www. cnmoc. navy. mil. educate Direction of Prevailing Winds Winds that blow from the sea often bring rain to the coast and dry weather to inland areas. Winds that blow to Britain from warm inland areas such as Africa will be warm and dry. Winds that blow to Britain from inland areas such as the Netherlands will be cold and dry in winter. Britains prevailing winds come from a south westerly direction over the Atlantic. The winds are cool in the summer and mild in the winter. Relief Climate can be affected by mountains.Mountains receive more rainfall than low lying areas because the temperature on top of mountains is lower than the temperature at sea level. That is why you often see snow on the top of mountains all year round. The higher the place is above sea level the colder it will be. This happens because as altitude increases, air becomes thinner and is less able to absorb and retain heat. Proximity To The Equator The proximity to the equator affects the climate of a place. The equator receives the more sunlight than anywhere else on earth. This is due to its position in relation to the sun (see right).The diagram shows that the equator is hotter because the sun has less area to heat. It is cooler at the north and south poles as the sun has more area to heat up. It is cooler as the heat is spread over a wider area. The Earth's Position in Relation to the Sun http://www. itl. net El Nino El Nino, which affects wind and rainfall patterns, has been blamed for droughts and floods in countries around the Pacific Rim. El Nino refers to the irregular warming of surface water in the Pacific. The warmer water pumps energy and moisture into the atmosphere, altering global wind and rainfall patterns.The phenomenon has caused tornadoes in Florida, smog in Indonesia, and forest fires in Brazil (see below) Devastation Caused by a El Nino-generated tornado in Florida http://news. bbc. co. uk Smog In Indonesia http://news. bbc. co. uk El Nino Causes Forest Fires in Brazil http://news. bbc. co. uk Human Influence The factors above affect the climate naturally. However, we cannot forget the influence of humans on ou r climate. We have been affecting the climate since we appeared on this earth millions of years ago. In those times, the affect on the climate was small.Trees were cut down to provide wood for fires. Trees take in carbon dioxide and produce oxygen. A reduction in trees will therefore have increased the amount of carbon dioxide in the atmosphere. The Industrial Revolution, starting at the end of the 19th Century, has had a huge effect on climate. The invention of the motor engine and the increased burning of fossil fuels have increased the amount of carbon dioxide in the atmosphere. The number of trees being cut down has also increased, meaning that the extra carbon dioxide produced cannot be changed into oxygen.

Positions and Duties on Board a Pirate Ship

Positions and Duties on Board a Pirate Ship Each of the members of the crew of a pirate ship had a specific position to play and a set of duties to go along with that role. A pirate ship was an organization much like any other business. Life on board a pirate ship was much less strict and regimented than on board a Royal Navy or merchant vessel of the time, but there were still duties that had to be done. There was a command structure, and different men had different jobs to make sure that everything went smoothly. Well-run and organized pirate ships were more successful, and ships that lacked discipline and leadership generally didn’t last very long. Here is a list of the common positions and duties on board a pirate ship. Captain Hulton Archive/Stringer/Getty Images Unlike in the Royal Navy or merchant service, where the captain was a man with a great deal of experience and complete authority, a pirate captain was elected by the crew, and his power was only absolute in the heat of battle or when giving chase. At other times, the captains wishes could be dismissed by a simple majority vote of the crew. Pirates tended to like their captains to be neither too aggressive nor too meek. A good captain had to know when a potential victim was too strong for them, without letting weaker quarry get away. Some captains, such as Blackbeard or Black Bart Roberts, had great charisma and easily recruited new pirates to their cause. Navigator It was hard to find a good navigator during the Golden Age of Piracy. Trained navigators could use the stars to figure out their latitude, and therefore could sail from east to west with reasonable ease, but figuring out longitude, north to south, was much harder and involved a lot of guesswork. That was fairly important: pirate ships often ranged far and wide. â€Å"Black Bart† Roberts worked much of the Atlantic Ocean, from the Caribbean to Brazil to Africa. If there was a skilled navigator on board a prize ship, pirates would often force him to join their crew. Sailing charts were also valuable and were confiscated as booty when discovered on board prize ships. Quartermaster After the Captain, the quartermaster was probably the most important man on the ship. He was in charge of seeing that the Captain’s orders were carried out and handled the day-to-day management of the ship. When there was plunder, the quartermaster divided it up among the crew according to the number of shares each man was due to receive. He was also in charge of discipline in minor matters such as fighting or minor derelictions of duty. More severe offenses went before a pirate court. Quartermasters often inflicted punishments such as floggings. The quartermaster would often board prize vessels and decide what to take and what to leave. Generally, the quartermaster received a double share, same as the captain. Boatswain The Boatswain, or Bosun, was in charge of the ship itself and keeping it in shape for travel and battle. He looked after the wood, canvas, and ropes that were of vital importance on board. He would often lead shore parties when supplies or repairs were needed. He oversaw activities such as dropping and weighing the anchor, setting the sails and keeping the deck clean. An experienced Boatswain was a very valuable man. They often got a share and a half of loot. Cooper Wooden barrels were very valuable, as they were the best way to store food, water, and other necessities of life at sea. Every ship needed a cooper  or a man skilled in making and maintaining barrels. Existing storage barrels had to be regularly inspected. Empty barrels were broken up to make space on small ships. The cooper would quickly put them back together if they stopped to take on food and water. Carpenter The carpenter was in charge of the ship’s structural integrity. He generally answered to the Boatswain and would fix holes after combat, keep the masts and yardarms sound and functional, and know when the ship needed to be beached for maintenance and repairs. Ships carpenters had to make do with what was at hand, as pirates usually could not use official dry docks in ports. Many times they would have to make repairs on some deserted island or stretch of beach, using only what they could scavenge or cannibalize from other parts of the ship. Ship’s carpenters often doubled as surgeons, sawing off limbs that had been wounded in battle. Doctor or Surgeon Most pirate ships preferred to have a doctor on board when one was available. Pirates frequently fought–with their victims and with one another–and serious injuries were common. Pirates also suffered from a variety of other ailments, including venereal diseases such as syphilis and tropical illnesses like malaria. If they spent a long time at sea, they were vulnerable to vitamin deficiencies like scurvy. Medicines were worth their weight in gold: when Blackbeard blockaded the port of Charles Town, all he asked for was a large chest of medicines. Trained doctors were hard to find, and when ships had to go without one, often times a veteran sailor with some common sense would serve in this capacity. Master Gunner If you think about it for a minute, you’ll realize that firing a cannon must be a tricky thing. You have to get everything right: the placement of the shot, the powder, the fuse... and then you have to aim the thing. A skilled gunner was a very valuable part of any pirate crew. Gunners usually were trained by the Royal Navy and had worked their way up from being powder-monkeys, young boys who ran back and forth carrying gunpowder to the cannons during battles. The Master Gunner was in charge of all of the cannons, the gunpowder, the shot and everything else that had to do with keeping the guns in working order. Musicians Musicians were popular on board. Piracy was a tedious life, and a ship could spend weeks at sea waiting to find a suitable victim. Musicians helped to pass the time, and having some skill with a musical instrument brought with it certain privileges, such as playing while the others were working or even increased shares. Musicians were often forcibly taken off of the ships of their victims. On one occasion, when pirates raided a farm in Scotland, they left behind two young women†¦ and brought a piper back to the ship instead.

CELTA Language Task Essays

CELTA Language Task Essays CELTA Language Task Essay CELTA Language Task Essay I have chosen an authentic article, for it gives students taste of real language in use, and provides them with valid linguistic data for their unconscious acquisition (Swan 1 985, p. 85). Furthermore, an authentic text provides learners with opportunities to experience language as it is used beyond the classroom (Nana 1999, p. 80) as opposed to scripted texts. Thus, an authentic text proves to be more essential to LET for it should engage and challenge students at this level. Believe there are no words that are crucial to an overall understanding of the article. Ere with Harmer (2001 , p. 272) with reference to pre-teaching: by giving them some or all those words, we deny them a chance to practice tackling authentic texts. Nonetheless, I would elicit some lexis to make sure the students have understood the text and managed to guess the meaning from the context. This however would be done ATA later stage of the lesson. Lead in/prediction: At the beginning of a typical English languag e lesson it is good to lead-in by activating the students schema, which is their pre-existent knowledge of the world (Cook, 69, 1989). By encouraging students to use what they already now, the opportunity for language learning is maximized. I would begin by displaying the main picture and the heading of the article, then ask the class to work in pairs. The students would be asked to predict what the topic of the newspaper article is (Appendix 1. 0). This is a very student centered activity which creates interest in the content of the text and activates schemata. Once the discussions quiet down, class feedback would be gathered. To ensure the students read for gist in the next activity, would only flag up three predictions on the board for the students to verify. This stage will leave the dents with a good reason to read (Harmer, p. 288). Skimming (Reading for gist): would ask the students to skim read the article (Appendix 2. 0) and ask them to discuss in pairs whether the predictions they made earlier were correct or not before doing a class discussion. However, to ensure that students gist read only I would give learners 3 minutes, so that they do not read the article intensively. This task is used to develop the students sub-skill Of reading for gist, or skimming (Scrivener, p. 185). Also to make students better readers, it is important to raise awareness that its not always essential to understand very word, as this could cause students to use their dictionaries and pause from reading (Scrivener, p. 153). Reading for further detail (Intensive reading In order to develop the sub skill of reading for further detail, set a series of true/false questions (Appendix 3. 0). The activity will test whether the student! Gained maximum information from the text (Harmer, p. 70). The true and false activities can fall both into reading for specific information and reading for detail, therefore it is very important to formulate appropriate questions, which will require the learner to read to find further detail as opposed to pacific piece of information. In order to have the students focus, they would work on their own, underlining the excerpts of text where they found an swers. Once done with reading and answering true/false statements, the students peer check and discuss their answers among themselves, referring to the highlighted text. Bellyacher quoted in (Alison, peg. 102) states that if there is a climate of trust and support in the classroom, then the students ARP more likely to contribute. One way of developing this is to allow pair checking of answers before open-class checking answers, the students will then be ore likely to contribute during the open class discussion. This promotes communicative language teaching. Furthermore, this would give me an opportunity to monitor student discussions. Once the conversation naturally quiets down I would gather whole class feedback. Nominating a student and also asking them to expand on their reasoning, as well as asking further questions or even getting their personal views. This is an important stage of the lesson, as Scrivener points out a lesson without feedback is teaching dhal proceeds forward without reference to what impact this is having on the g. 73). This is to show their engagement with the text, as opposed to simply answering true/false statements. This could be done with some follow up questions, as Harmer (2007, peg. 75) says, we should always ask the students where in the text they have found the answer, as it provoke a detailed study of the text. Post-reading free discussion The last activity is a free discussion, which would allow me to monitor further for any errors in meaning, form or pronunciation (MAP) while the students discuss their own opinions on these inventions in groups of four. Would first vie an example in the form of my own opinion to present the language in context and encourage students to express their thoughts on the topic. The purpose of the post reading task is to allow the students to utilize the studied vocabulary. I would then gather feedback from the class, nominating group members to summaries what their team has discussed, whether they agree with the creators or not. Having the chance to monitor two major discussion in the class, should at this stage have gathered some errors that the students have made, either with meaning, form or pronunciation. I have left his to the end, as interrupting student discussions to correct an error could be embarrassing, and would disrupt the flow of the lesson. Whereas, towards the end of the lesson it is easy to grab class attention and go through some of the errors together, eliciting the correct MAP from the students, in order to give them a chance to correct their mistakes and fossil the correct form. Reading like listening are receptive language skills and developing these skill: is key to increasing student comprehension and appreciation of the English language. Thus, a well-structured lesson which follows the SEA (Engage, stucco ND activate) stages is essential to the learners development.

What role does technology play in development Essay

What role does technology play in development - Essay Example Knowledge and technology should be considered together otherwise development is hampered. Nowadays information and communication technologies are the potential for the development. Therefore it is necessary to pay attention to distribution and application of these technologies in order to give equal rights to developed and developing countries (Wehelive, 2005, p. 39). This research paper considers technology and development with regard to information society. The works by Bell, Schumacher, Smith, Ovitt, Steinberg, Castells and others are focused on thee discussion of connection between technology and development. The majority of researchers claim that technology and development are closely connected and technology is considered to be a crucial factor in a modern society. On the other hand, inequity of technology distribution between developed and developing countries may be a drawback of development. Moreover, technological progress may be an obstacle to development. Thus it is relevant to discuss not technology, but intermediate or appropriate technology as it is suggested by Schumacher and Ovitt. Daniel Bell is focused on the study of the information society. His writings are mainly focused on three main issues: post-industrial information and workforce; the second one is about information flows; the third is focused on the discussion of connection between computers and the information revolution. Bell has always connected the society first with goods and then with services. Furthermore, Bell draws parallels between information and knowledge (Duff, 1998, p. 373). He emphasizes the significance of theoretical knowledge and its importance for a modern society. Thus Bell’s claim about the post-industrial society concerns theoretical knowledge as the only way to successful development. He suggests knowledge to be codified into symbols and be applied

Audio Culture Essay Example | Topics and Well Written Essays - 2000 words

Audio Culture - Essay Example In those days, radio content was most based on speech programming later by the introduction of Television media radio diverted its major entertainment towards musical programming (Crook, 2011). The purpose of this paper is to analyze different radio texts to present a discourse by evaluating the social, cultural, political and economic contexts. Four different audio programs have been selected for the analysis of radio based on programming, production, audience and cultural context. The analysis will be categorized broadly into Conversation Analysis and Discourse Analysis focusing on a use of music, sound, text and technology in different sorts of programs by different presenters. Conversation Analysis is defined as a method of analyzing the audio or video tapes for discovering how the participants of the conversation in the audio understand each other’s points and respond accordingly with the main focus on generation of sequences of action (Wooffitt, 2005). Or in other words the purpose of Conversation Analysis is to reveal the tactic reasoning procedures and sociolinguistic capabilities triggering the production and evaluation of the audio conversation in an organized sequence of interaction (Hutchby, 2006). Discourse Analysis or Critical Discourse Analysis is a method of understanding how social power (radio) is used or abused in relation with spoken or written languages. The method particularly focuses on studying the dialectal relationship with the discourse aspect of the social practices and the structure of society (Tolson, 2006). It is a news show presented by Victoria Derbyshire. The show includes news on social and cultural issues, political news and sports news in the United Kingdom and all around the world. Based on the conversation analysis the presenters interact with each other only when it’s necessary, like to hand over the conversation from one person to another. The news show is led by Victoria Derbyshire dominantly as she goes