Monday, January 27, 2020
Input And Output Devices Computer Science Essay
Input And Output Devices Computer Science Essay The computer will be of no use unless it is able to communicate with the outside world. Input and Output devices are required for users to communicate with the computer. In simple terms, input devices bring information into the computer and output devices bring information out of a computer system. These input/output devices are also known as peripherals since they enclose the CPU and memory of a computer system. A hardware device that accepts inputted information and also has the capability of outputting that information. Good examples of an input and output devices are a floppy diskette drive and a hard disk drive. An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world. In computing, input and output, refers to the communication between an information processing system (such as computer), and the outside world. Inputs are the signals or data sent to the system, and output are the signals or data sent by the system to the outside. The most common input devices used by the computer are the keyboard and mouse. The keyboard allows the entry of textual information while the mouse allows the selection of a point on the screen by moving a screen cursor to the point and pressing a mouse button. The most common outputs are monitors and speakers. Output devices Examples of output devices Any peripheral that receives and/or displays output from a computer. To the right is a picture of an inkjet printer and a good example of an output device. Below is a listing of all the different types of computer output devices found on a computer. Sound card Video card Projector Monitor Speakers Printer Features and Functions Sound Card D:MMU fileSEM 3Computer Applicationsound card.jpg A sound card (also known as an audio card) is a computer expansion card that facilitate the input and output of audio signals to and from a computer under control of computer programs. Typical uses of sound cards comprise providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education, and entertainment (games). Many computers have sound capabilities built in, while others necessitate extra expansion cards to provide for audio capability. Video CardD:MMU fileSEM 3Computer ApplicationVideo_Card.jpg A video card, video adapter, graphics-accelerator card, display adapter or graphics card is an extension card whose function is to generate and output images to a display. Many video cards offer added functions, such as accelerated rendering of 3D scenes and 2D graphics, video capture, TV-tuner adapter, MPEG-2/MPEG-4 decoding, FireWire, light pen, TV output, or the ability to connect multiple monitors (multi-monitor). Other modern high performance video cards are used for more graphically demanding purposes, such as PC games. images7 Projector A video projector takes a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for meeting room presentations, classroom training, home theatre and live events applications. Projectors are widely used in many schools and other educational settings, connected to an interactive white board to interactively teach pupils. Monitor images5 A monitor or display (sometimes called a visual display unit) is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD), at the same time as older monitors use a cathode ray tube (CRT). Speakersimages8 Computer speakers, or multimedia speakers, are speakers external to a computer that disable the lower fidelity built-in speaker. They often have a low-power internal amplifier. The standard audio connection is a 3.5mm (1/8 inch) stereo jack plugs frequently colour-coded lime green (following the PC 99 standard) for computer sound cards. A plug and socket for a two-wire (signal and ground) coaxial cable that is generally used to connect analogy audio and video components. Also called a phono connector, rows of RCA sockets are found on the backs of stereo amplifier and numerous A/V products. The prong is 1/8 thick by 5/16 long. A few use an RCA connector for input. There are also USB speakers which are powered from the 5 volts at 200 milliamps provided by the USB port, allowing about half a watt of output power. Printerimages6 In computing, a printer is a peripheral which produces a hard copy (permanent readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are first and foremost used as local peripherals, and are attached by a printer cable or, in most new printers, a USB cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interfaces (typically wireless and/or Ethernet), and can serve as a hardcopy device for any user on the network. Person printers are frequently designed to support both local and network connected users at the same time. In addition, a small number of modern printers can directly interface to electronic media such as memory sticks or memory cards, or to image capture devices such as digital cameras, scanners; some printers are combined with a scanners and/or fax machines in a single unit, and can function as photocopie rs. Printers that include non-printing features are sometimes called Multifunction printers (MFP), Multi-Function Devices (MFD), or All-In-One (AIO) printers. Most MFPs include printing, scanning, and copying in the middle of their features. Advantages and Disadvantages of Output Devices No Output devices Advantages Disadvantages 1 Monitor Comparatively cheap and reliable, can display text and graphics in a wide range of colures. They are also quiet and do not squander paper. No enduring copy to keep and unsuitable for users with visual problems. 2 Printer The purchase cost is low and the running costs are very low. They can print fairly quickly, particularly if you remember that multiple copies are being printed in one print run. They are robust and can operate in harsh environments. If several sheets of self-carbonating paper are placed into the printer then the impact will produce duplicate copies. The printing quality is low these printers produce low to medium quality black and white printing and can only print low resolution graphics. Because of the impact of the pins against the paper, these printers can be quite noisy. 3 Projector Enables a lot of people to be able to see something even from a distance Image quality may not be as good when projected. 4 Speakers Cheap and generally available.Ãâà Capable of producing very high quality sound. They are an analogue device so the digital sound signal has to be converted, usually by a sound card. Input Devices A hardware device that sends information to the computer. Without any input devices a computer would simply be a display device and not allow users to interact with it, much like a TV. To the right are a Logitech trackball mouse and an example of an input device. Below is a listing of all the different types of computer input devices found on a computer. Example of Input Devices Keyboard Gamepad Digital camera Mouse (pointing device) Microphone Webcam Joystick Scanner MIDI Keyboard Features and Functions for input devices Keyboard20071004_razer_lycosa In computing, a keyboard is an input device, partially modelled after the typewriter keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys at the same time or in sequence. While most keyboard keys produce letters, numbers or signs (characters), other keys or real-time key presses can produce actions or computer commands. Gamepad D:MMU fileSEM 3Computer Application350__1_full_game_pad_001.jpg.png A gamepad (also called Joypad or control pad), is a type of game controller held in the hand, where the digits (especially thumbs) are used to offer input. Gamepads generally feature a set of action buttons handled with the right thumb and a direction controller handled with the left. The direction controller has traditionally been a four-way digital cross (also named a Joypad, or alternatively a D-pad), but most modern controllers as well (or as a substitute) feature an analog stick. Digital Camera images Most digital cameras function in much the same way as a traditional camera that uses film to record images, except that in place of the film, images are captured and preserved in the cameraà ¢Ã ¢Ã¢â¬Å¡Ã ¬Ã ¢Ã¢â¬Å¾Ã ¢s digital memory, which may be built-in or which may be on a detachable memory card. Mouserazer_naga_1 In computing, a mouse (plural mice, mousses, or mouse devices.) is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the users hands, with one or more buttons. It sometimes features other elements, such as wheels, which allow the user to perform a variety of system-dependent operations, or extra buttons or features can additional control or dimensional input. The mouses motion typically translates into the motion of a cursor on a display, which allows for fine control of a Graphical User Interface. Microphone images1 A microphone (colloquially called a mic or mike) is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal .Microphones are used in many applications such as telephones, tape recorders, karaoke systems, hearing aids, motion picture production, live and recorded audio engineering, FRS radios, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic checking or knock sensors. Web Camimages4 A webcam is a video capture device connected to a computer or computer network, frequently using a USB port or, if connected to a network, Ethernet or Wi-Fi. The mainly popular use is for video telephony, permitting a computer to act as a videophone or video conferencing station. This can be used in messenger programs such as Windows Live Messenger, Skype and Yahoo messenger services. Other popular uses, which include the recording of video files or even still-images, are accessible via numerous software programs, applications and devices. Webcams are known for low manufacturing costs and flexibility, making them the lowest cost form of video telephony. The term webcam may also be used in its original sense of a video camera connected to the Web ceaselessly for an indefinite time, rather than for a particular session, generally supplying a view for anyone who visits its web page over the Internet. Some of these, for example those used as online traffic cameras, are expensive, rugged professional video cameras. Joystickimages A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer. A popular variation of the joystick used on modern video game consoles is the analogy stick. The joystick has been the principal flight control in the cockpit of many aircraft, chiefly military fast jets, where centre stick or side-stick location may be employed. Joysticks are also used for controlling machines such as cranes, trucks, submerged unmanned vehicles, wheelchairs, surveillance cameras and zero turning radius lawn mowers. Miniature finger-operated joysticks have been adopted as input devices for smaller electronic equipment such as mobile phones. Scannerimages3 In computing, a scanner is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning wands to 3D scanners used for industrial design, overturn engineering, test and measurement, orthotics, gaming and other applications. Mechanically driven scanners that move the document are typically used for large-format documents, where a flatbed design would be impractical. MIDI Keyboardimages2 A MIDI keyboard is a piano-style digital keyboard device used for sending MIDI signals or commands to other devices connected to the same interface as the keyboard. MIDI is an acronym for Musical Instrument Digital Interface (protocol). The basic MIDI keyboard does not produce sound. In its place, MIDI information is sent to an electronic module capable of reproducing an array of digital sounds or samples that resemble traditional analog musical instruments. These samples are also referred to as voices. Advantages and Disadvantages of Input Devices No Input Devices Advantages Disadvantages 1 Digital Camera No film is needed and there are no film developing costs Unwanted images can be deleted straight away Images are already digital and can easily be transferred to a computer and edited or transferred over the Internet Special image editing software can allow a huge range of adjustments and special effects to be tried Images often have to be compressed to shun using up too much expensive memory. 2 Joystick Easy to learn to use.Ãâà Very simple design so they can be reasonably priced. Control can be a bit crude as the directions in simple joysticks are limited to forward, backwards, left and right.Ãâà Better models offer diagonal movement or better. 3 Keyboard dependable for data input of text and numbers. Usually supplied with a computer so no additional cost. Specialized keyboards are available. Users may be slow for not very accurate typists. Slow for accessing menus etc. and difficult to use if you want to move objects around the screen. Difficult for people unable to use keyboards through paralysis or muscular disorder. 4 Microphone Voice recognition software can be used to convert your voice into text or to control menu options on a phone system. Stored audio files can take up a lot of memory. Voice commands can be difficult to recognise by the software. 5 MIDI keyboard Data from a musical instrument is easily captured and edited with a computer. MIDI files are small. MIDI files can be recorded on one type of instrument and played back on another. Audio cannot be recorded directly as an audio file such as MP3. The playback depends on the instrument/computer sound card so may not sound the same as the original. Only the note and the timing are stored. 6 Mouse Ideal for use with desktop computers. more often than not supplied with a computer so no additional cost. All computer users tend to be familiar with using them. They need a flat space close to the computer. The mouse cannot easily be used with laptop, notebook or palmtop computers. (These need a tracker ball or a touch sensitive pad called a touch pad). 7 Scanner Flat-bed scanners are very accurate and can produce images with a far higher resolution than a digital camera. Can produce very large image files which need a lot of computer memory to view and edit. Types of Pointing Devices pointing stick.jpg The is a small number of examples of pointing devices are pointing stick, touch screen, touch pad, joystick. A pointing stick is a pressure sensitive small nub used like a joystick. Its more frequently than not found on laptops embedded between the G, H, and B keys. It operates by sensing the force applied by the user. The corresponding mouse buttons are commonly placed just below the spacebar. It is also found on mice and some desktop keyboards. Touch Screen images13 A touch screen is a device embedded into the screen of the TV Monitor, or System LCD monitor screens of laptop computers. Users interrelate with the device by physically pressing items shown on the screen, either with their fingers or some helping tool. Touch screens could be used in couple with stylus pointing devices, while those powered by infrared do not require physical touch, but just differentiate the movement of hand and fingers in some minimum range distance from real screen. Touchpadimages9 A touchpad or track pad is a flat surface that can detect finger contact. Its a motionless pointing device, commonly used on laptop computers. At least one physical button normally comes with the touchpad, but the user can also generate a mouse click by tapping on the pad. Advanced features include pressure sensitivity and special gestures such as scrolling by moving ones finger along an edge. Joysticksjoystick.jpg Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer. A popular variation of the joystick used on modern video game consoles is the analog stick. Joysticks are also used for controlling machines such as cranes, trucks, and underwater unmanned vehicles. Types of Keyboard What is Keyboard? Keyboard is a set of typewriter that enable to you to enter data into the computer. The key on the computer keyboard got alphanumeric keys, punctuation keys, and special keys. There are several types of keyboard. For examples, notebook keyboard, PDA stylus, Tablet PCs, Wireless keyboard, and Ergonomic keyboard. For notebook keyboard will with the screen and the CPU. Keyboards on laptops and notebook computers more often than not have a shorter travel distance for the keystroke and a reduced set of keys. They may not have a numerical keypad, and the function keys may be placed in locations that different from their placement on a standard, full-sized keyboard. The layout is based on the 104-key Windows design, except the keys are crammed into the available space. There is no numeric keypad, but you can see the labels on keys in the middle of the keyboard where it is superimposed (the letter J has the numeral 1 on it, K is 2, and so on). The Fn key in the lower left i s used to activate particular options when used in combination with the function keys at the top of the keyboard. z_011204note.jpg PDA Stylus images11 PDA stylus is a touch type keyboard. That a keyboard is needed for extensive typing, a person can use a fold up keyboard. The fold-up keyboards have all of the room of usual keyboards, yet still compact. Tablet PCs Keyboard Tablet PCs keyboard is the the majority common peoples in the world using. It use to type any data into the computer. It have a place for number keys, alphanumeric keys, punctuation keys, and special keys. Wireless Keyboard imagesCAH7GN2X.jpg Wireless Keyboard is the newest keyboard that came out this few years. The keyboard can use without wire, but the others function are same with the normal keyboard that we use. Ergonomic Keyboard images112 Ergonomic keyboard is computer keyboard designed with ergonomic considerations to minimize muscle strain and a host of related problems. An ergonomic keyboard may decrease muscle strain and reduce risk of Carpal Tunnel syndrome, but there is no clear evidence of benefit. After a user takes the time to adjust to this style of keyboard, these keyboards can make typing easier, faster and less awkward. The keys separated into two or three groups, allowing the user to type at a different angle than the typical straight keyboard. Types of Printer Printer is classified into 3 types. There are impact printer, nonimpact printer and specialty printer. The example of impact printer is Dot-matrix. Dot matrix printers are still commonly used in low-cost, low-quality applications like cash registers, or in demanding, very high volume applications like invoice printing. dot matrix printer.jpg The nonimpact printers have Inkjet and Laser. For the Inkjet, operate by propelling variably-sized droplets of liquid or molten material (ink) onto almost any sized page. They are the most ordinary type of computer printer for the universal consumer. The laser is a common type of computer printer that rapidly produces high quality text and graphics on plain paper. But the price will more expensive than others. laser.jpgliquid inkjet.jpg Inkjet Printer Laser Printer Specialty Printersmultifunction.jpg The specialty printers have multifunction, plotters and thermal printers. A multifunction printer is an office machine which incorporates the functionality of multiple devices in one, so as to have a smaller footprint in a home or small business setting or to provide centralized document management/ distribution/ production in a large-office setting. A typical multifunction printer may act as a combination of some or all of the printer, scanner, photocopier, fax and email. Plotterplotter.jpg Plotter is a computer printing device for printing vector graphics. In the past, plotters were generally used in applications such as computer-aided design, though they have generally been replaced with wide-format conventional printers. It uses a pen that moves over a large revolving sheet of paper. Thermal Printerthermal.jpg A thermal printer produces a printed image by selectively heating coated thermo chromic paper, or thermal paper as it is generally known, when the paper passes over the thermal print head. The coating turns black in the areas where it is heated, producing an image. Two-color direct thermal printers are capable of printing both black and an supplementary color (often red), by applying heat at two different temperatures. Types of Monitor Monitor is an output device that resembles the television screen and uses a Cathode Ray Tube (CRT) to display information. The monitor is associated with a keyboard for guide input of characters and displays the information as it is keyed in. It also displays the program or application output. Like the television, monitors are also available in different sizes. Liquid Crystal Display (LCD) LCD was introduced in the 1970s and is now applied to display terminals also. Its advantages like low energy consumption, smaller and lighter have paved its way for usage in portable computers (laptops). Devices used to get sound, video, and images into the computer Video capture is one of the most important hardware to be used for multimedia work on a personal computer. Video-capture results will depend on the performance and capacity of all of the components of your system working together. Video capture from analog devices like video camera requires a special Video capture card that converts the analog signals into digital form and compresses the data. Video-capture card use various components of the computer to pass frames to the processor and hard disk. For high-quality video, a video-capture card must be able to capture full-screen video at a high rate. For example for a full-motion video, the card must be capable of capturing about 35 frames per second at 720 by 480 pixels for digital video and 640 by 480 for analog video. To determine what settings will produce the best results for your projects, you must be careful in defining these parameters. A sound card is a device that attaches to the motherboard to enable the computer to input, process, and deliver sound. The sound card generates sounds; records sound from analog devices by converting them to digital mode and reproduce sound for a speaker by reconverting them to analog mode. Creative Labs Sound Blaster is a standard sound card, to the extent that some people use the name as a generic term. A video adapter provides extended capability to a computer in terms of video. The better the video adapter, the better is the quality of the picture you see. A high quality video adapter is a must for you while designing your multimedia project. Conclusion Described is an input and output device for inputting or outputting data of an electronic equipment. The input and output device is designed for being detachably mounted to the electronic equipment in at least two different positions. The input and output device features a first contacting arrangement which, independent of the selected position in the mounted state of the input and output device on the electronic equipment, electrically comes in connection with a second contacting arrangement present on the electronic equipment. In one embodiment, orientation of the device may be varied, thereby enabling it to be coupled to a receiver by a bayonet connection and with a set of contacting arrangement engaging the second contacting arrangement in any orientation. Furthermore, described is an operating and display module, as well as to a combination of an electronic equipment and an input and output device that can be detachably mounted thereto.
Sunday, January 19, 2020
Pre 1914 Prose Study Mary Shelleyââ¬â¢s ââ¬ÅFrankensteinââ¬Â Essay
à He nearly succeeds in catching it at the North Pole where Captain Walton rescues him. Exhausted he die and Frankensteinââ¬â¢s monster vows to kill himself before disappearing into the ââ¬Å"distance and darknessâ⬠. Chapter five begins with Victor Frankenstein revulsion of the monster he has created and Shelley describes the creatureââ¬â¢s vile features that shriek terror into the reader alone. In revolt Victor leaves the room at the very disgust of what he was brought into this world and attempts to gain his precious ââ¬Å"sanctuary of sleepâ⬠. While he sleeps he dreams of seeing Elizabeth his one love, however as he plants his first kiss on her lips her features change and he appears to eventually hold the dead corpse of his dead mother. He wakes up to find the monster by his bedside peering at him and in anguish runs out of his rented apartment and through the town with paranoid strides fearing he will see the monster at every turn. He finds refuge in the courtyard while lost in his daydreams of the monstrosity he has created, he notices his good friend Clerval and brings him to his accommodation before he has time to think properly. When he reaches his apartment he Is overjoyed that the monster is no longer in the vicinity and welcomes Clerval into his rented home. Dr Frankensteinââ¬â¢s content emotions are quickly destroyed as he imagines seeing the monster lurching for him and breaks down to a fit. Clerval worries for his friends health and nurses him back to health after witnessing Victors fluctuating emotions. Shelley was part of the romantic novelist of the earlier 19th century, who like Shelley used Gothic elements to add provoke terror in a reader. Descriptions such as ââ¬Å"Corpse of my dead mother in my armsâ⬠and â⬠Shrivelled complexions all are examples of gothic elements, though the more mysterious and alluding comments such as ââ¬Å"I saw the dull eye of the creatureâ⬠give the impression this creature isnââ¬â¢t alive and that it is an inanimate object been brought to life through personification elaborated descriptions full of eccentric adverbs. Shelley was a naturally beautiful writer who could conjure sentences as if they flowed from a river of her knowledge. She uses great amounts of writing styles inspired probably from the intellectuals she grew up around. There is a great contrast in sentence length with short lines such as ââ¬Å"How ill you areâ⬠and sentences that contain over fifty words for instance; ââ¬Å"I took refuge in the courtyard belonging to the which I inhabited; where I remained during the rest of the night, walking up and down in the greatest agitation, listening attentively, catching and fearing each sound as if it were to announce the approach the demonical corpse to which I had so miserably given lifeâ⬠. Repetition is also a trait of Shelleyââ¬â¢s writing style; ââ¬Å"Save me, save meâ⬠and ââ¬Å"Dear, dear friendsâ⬠are both examples of repetition. The use of her adjectives stipulate her close use of gothic rudiments with dark and mystifying words such as ââ¬Å"Drearyâ⬠, ââ¬Å"Miserablyâ⬠and ââ¬Å"Hideousâ⬠, yet also her choice of colour reflect on her gothic style such as ââ¬Å"dull yellowâ⬠. Another topic to indulge in is Shelleyââ¬â¢s use of contrast in a variety of elements. Colour is again is used in contrast for gothic descriptions such as ââ¬Å"Lustrous Blackâ⬠and ââ¬Å"Pearly Whiteâ⬠a common metaphor. The actual pace of the narrative is not an unexpected contrast to build tension and fear, and is commonly used in all sorts of genres and mediums, like songs and television. This practice can be used to build many emotions from love to action yet works just as well if not the best with fear. She uses a contrast of dream and reality this could be because her original idea for the plot came to her in a dream. Yet, however it seems in either the sub consciousness or actual consciousness it is always a horrific period. Finally a contrast in emotions is very blatant such as joy, revulsion and terror all blend together with Frankensteinââ¬â¢s original image of a beautiful creation to its consequential repulsiveness. This brings me to my final point of Mary Shelleyââ¬â¢s use of fluctuating emotions to provoke the sense of fear in the reader. Frankenstein expects a beautiful creature to be born of his labour, yet is shocked when he unveils his creation for the first time â⬠How can I describe my emotions at this catastropheâ⬠. Horror soon sets in at the monstrosity and almost failure of his dream sets in ââ¬Å"But now that I have I have finished the beauty of the dream of the dream has vanished and breathless horror and disgust fill my heartâ⬠. This quickly turns to frightened â⬠I did not dare return to the apartmentâ⬠, again his emotions fluctuate to a paranoid loneliness ââ¬Å"Like one when on a lonely road, Doth walk in fearâ⬠and finally a huge contrast for the previous emotions to happiness â⬠I felt suddenlyâ⬠¦ calm and serene joyâ⬠. Shelley fluctuates Frankensteinââ¬â¢s emotions so rapidly is almost becomes difficult to follow them, yet perhaps this is the desired effect as the confusion only adds the horror you are reading. To conclude, Mary Shelley one of the greatest female novelist of her time if not history efficiently and captivatingly uses techniques, which are still used today in writing. They are not restricted to but she certainly chooses over others mainly are predominately gothic elements; common of early 19th century ââ¬Å"romanceâ⬠authors. She also makes use of the fluctuating emotions, contrast and language as I have described in earlier paragraphs. Benjamin Semens Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Mary Shelley section.
Friday, January 10, 2020
Biology Dna Research Pape Essay
DNA is a tool of great use throughout the world. Especially when it comes to the field of forensic science, DNA is the most important tool of all. What is DNA? DNA, short for deoxyribonucleic acid, is a group of molecules that hereditary information in which guides development and functioning throughout the body. ââ¬Å"DNA is to justice as a telescope is to the stars; not a lesson in biochemistry, not a display of the wonders of magnifying glass, but a way to see things as they really are.â⬠(Barry Scheck and Peter Neufeld, Actual Innocence) DNA profiling was first developed by two different scientists on opposite ends of the world: Sir Alec Jeffreys (UK) and Kary Mullis (US). Jeffreys came up with DNA fingerprinting and Mullis came up with a method called polymerase chain reaction (PCR). In 1984, Sir Alec Jeffreys, a professor from the University of Leicester, discovered a way of using DNA analysis through fingerprinting. () DNA fingerprinting method used variations in the gene tic code in order to identify individuals. During Dr.Jeffreysââ¬â¢ research, he found that certain regions of DNA contained DNA sequences that were repeated over and over again. He also found that the number of repeated sequences present in a sample can differ between individuals. (John M. Butler) Fingerprinting was first used in an immigration case to determine the identity of a British boy, who was detained from his family when they had emigrated from Ghana to the United Kingdom. The first time DNA testing was used forensically with the police was in a major case of two young girls who were sexually assaulted. In 1986 Lynda Mann and Dawn Ashworth were raped and brutally murdered. Investigators found traces of blood and semen at the sceens. Both crimes were committed in the same village which led police to determine that these crimes were committed by the same man. A man of the village had confessed to both murders. When his blood sample was compared to the semen recovered there was no match to either sample. Police were determined to find the man that did this so they conducted a mass screen to collect blood samples from every male in all the surrounding villages. Over 4000 men were tested and none of them came up as matches. A year later a woman had reported to the police that she had overheard a man bragging about how he had pretended to be his friend, Mr. Colin Pitchfork, and gave a blood sample for him. Police brought in Mr. Pitchfork for questioning and ask him for a blood sample as well. The test results came back and determined that he was a positive match for bothà samples of semen that were collected from the crime scenes. Colin Pitchfork was then sentenced to life in prison. (The Blooding, 1989) During the same year, Kary Mullis with the help of the human genetics team at the Cetus Corporation came up with the PCR technique. Polymerase chain replication is a biochemical technology in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence. At first when used Mullis didnââ¬â¢t want to use thermal cycling because he wanted it to react on its own but in later findings he saw that by using the thermal cycling it sped up the process. Thermal cycling of the DNA is when the samples of DNA go through cycles of heating and cooling of the DNA reaction in order for DNA melting and enzymatic replication of DNA. The first time that PCR was used was in a forensic case dealing with evidence of locus. Soon after PCR was publicized scientist began to develop many new kinds of PCR. Throughout history technology has helped to produce more ways of using DNA as a forensic tool. According to the East Midlands Forensic Pathology Unit, ââ¬Å"although accurate and reproducible, this original method of analysis required the use of a large amount of high quality DNA, which is not always recovered during forensic investigations. Two big breakthroughs occurred during the late 1980s and early 1990s that would form the basis of DNA profiling techniques as they are recognized today.â⬠(East Midlands Forensic Pathology Unit, 2010) ââ¬Å"An alternative class of DNA marker, the microsatellite or short tandem repeat (STR) marker and an alternative method for DNA visualization, PCR amplification and fluorescent labeling would greatly increase the sensitivity of DNA profiling methods and increase their use for criminal investigation,â⬠stated Saferstein (Forensic Science: From the Crime Scene and Lab, 2012). Another new development with DNA was Hair DNA Typing. In 1996, the FBI initiated a program to compare human head and pubic hairs through mitochondrial DNA. When pulled from the head, hairs have a follicular tag, which is basically a piece of tissue surrounding the hairââ¬â¢s shaft near the root. This follicular tag is of great importance because that is the main source of DNA of hair. Recently in the summer of 2011, a cold-case murder of a five year old girl in 1993 was solved by using DNA hair analysis. At the time of the murder police had suspected the gi rlââ¬â¢s next door neighbor, forty-one year old Nick Stofer, but because of the lackà of evidence the police could not build a case against him. Police had taken blood and hair samples from Stofer but hair DNA typing was not around at the time. According to the head detective in charge, Collins, the scent tracking dogs that had helped them to locate the body continued to follow the scent and led them back to Stoferââ¬â¢s house. ââ¬Å"We wanted to put the cuffs on (Stofer) so bad, but we couldnââ¬â¢t because the evidence was not there,â⬠stated Collins, ââ¬Å"So over time, the pain, the anguish of not being able to do that kept the fire alive and it was terribly frustrating. Thatââ¬â¢s why weââ¬â¢re here today. It may be therapy for us to be able to say itââ¬â¢s over. All of the work the police and the family and everyone put into it finally came to a conclusion.â⬠ââ¬Å"Over time, DNA analysis has advanced,â⬠said Katie Featherston, forensic scientist at the Colorado Bureau of Investigation. ââ¬Å"In 1993 it was not available at the CBI lab, but over time we have been able to deal with samples that are smaller and smaller, and/or less pristine. Those advances allowed us to do the DNA analysis on this case.â⬠In the end Stofer was found guilty but could not be arrested because Stofer had passed away a few years before. (ABC, September 2011) The final major part of the DNA typing process is the way it is collected and preserved. If not taken care of properly the DNA will not hold up as evidence for a court case. Any piece of clothing or material that is found in a crime scene is to be taken care of lightly with minimum contact. (Criminalistics,2007) Safety considerations and the avoidance of contamination calls for the wearing of face masks, latex gloves, shoe covers, and possibly coveralls. In most forensic labs and teams, evidence is required to be photographed and collected in either a paper envelope or a plastic Ziploc bag. According to scientist by the evidence being kept in these envelops and bags itââ¬â¢ll keep the evidence from being damaged. Also if there seems to be any possibility of fingerprints at the scene anything with a surface will be dusted and taken to get a genetic fingerprint to compare to in the system. (Anthony J. Bertino, Forensic Science) Since DNA typing was discovered there have been many inventions. At home DNA tests, paternity tests, genetics testing. Now a days technology is so advanced with DNA typing that women who are pregnant now can know if their baby will come out with brown, red, blonde or no hair, if their baby will have blue, green, brown, or hazel eyes. They can even find out if their child will have any genetic disorder. All because of Jeffreysââ¬â¢ and Mullisââ¬â¢Ã discoveries with DNA. So as you can see throughout the years DNA typing has changed drastically throughout the years. It went from being something of an experimental value to an important foren sic tool. And with the help of technology it has gotten even better. Not only is the typing helpful but the DNA, itself is a major part of it. Without DNA none of these analyses would be possible. DNA has change science and the world all at the same time.
Thursday, January 2, 2020
The Nature of Justice in Society and the Individual...
The study of Ethics is a diverse one encompassing many topics and having many applications. Some of the age-old questions inherent to Ethics refer to the nature of justice. Justice is the one of the oldest concepts in existence and as such has been discussed by many a philosopher over the ages. Plato discussed Justice at length and this paper will discuss the following questions relating to justice based upon his findings: what is Platoââ¬â¢s account of the nature of justice for the individual, how does Plato build his account, why does Plato take it that the claim made by Thracymachus is altogether mistaken ââ¬â if indeed he does? Plato finds that justice is the harmonious balance of the three elements of the soul.â⬠¦show more contentâ⬠¦This is like the case in which writing too small to be read, using eyes alone and solitary from a frame of reference, might be capable of understanding if it were to be found writ large elsewhere. ââ¬Å"â⬠¦we shall expect to find that the individual soul contains the same three elements and that they are affected in the same way as are the corresponding types in society,â⬠(Plato 54). Therefore, Plato makes his case through his plan for an ideally just society. Plato believes that in many ways a minimal state is best; it provides for benefits of specialization, division of labor, and the capability to meet the needs of the people. The problems with a minimalist society are that some people within the society will always want luxuries, some people outside the society will want to take the benefits of the society, and that the benefits of the society are incapable of being guarded by guardians alone. This last point is made clear through Platoââ¬â¢s explanation that the presence of guardians requires the allocation of power to certain portions of society; any time that power is allocated it must be checked. Platoââ¬â¢s question is: who will guard us from the guardians? This question is not easily answered without causing a pattern of infinite regression; for to add more guardians is simply to create more of the problem. Plato also discusses the possibility of a luxurious state. In this state the needs of the people are met,Show MoreRelatedJustice Is The Legal Or Philosophical Theory Of Justice1503 Words à |à 7 PagesJustice is the art which gives to each man what is good for his soul. 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