Essay --

Existentialism is a complicated and diverse set of theories and beliefs. Jean Paul Sartre’s beliefs are very complex as well in how he conveys them to the reader. He firmly believes that the actions of the person should be what they are and that the outside world should not shape a person. Through his play No Exit, each character would come to represent a key point in existentialism, authenticity, angst and absurdity. The definition of authenticity is to know oneself, accept it and be true to it. One major display of authenticity is the character of Inez and how she acts. The way she holds herself is very true to existentialism and that is due to her authenticity. She knows the kind of person that she used to be and even said it herself,† I was what some people down there called ‘a damned bitch.’ Damned already. So it’s no surprise, being here.†(p. 25). With this response, Sartre shows that Inez acknowledges her mistakes and flaws, she truly knows herself. This is a very free way of thought. It has much leeway into what a person could decide to do with their life or not and Inez decided to do whatever she set her mind to. She accepts what she has done; she even says â€Å"You know, I don’t regret a thing† (p. 25) and even embraces it, as her actions were practically a part of who she was as a whole. She does not care how she comes off to others, even if she is â€Å"rather cruel† (p. 26), she does what she wants and is how she wants to be. Another factor of authenticity shown is the rejection of stereotypes. For example, human feeling and going along with social norms pertaining to the consoling of those that are sad are what would be expected of a person in normal society but Inez goes on to say â€Å"Human feeling. That is beyond my range. I’... ... Absurd was the meaning Garcin came to realize about the room and Estelle and Inez. Overall, No Exit is a great work on part of Jean-Paul Sartre. In it he was able to include at least three of the very key facets of his beliefs in existentialism. They were Authenticity, Angst, and finally, The Absurd. The play had various examples in and of itself but most of them came from the characters and their behavior. Each character had a personality that fit very well into the certain mold that was a part of existentialism. Inez was sure of herself and who she was, Estelle was afraid to make any decision that could influence her as a person and finally Garcin took away or added meaning to the scheme of things. Sartre’s No Exit brought all of these facets together in a very cohesive fashion and overall showed how Existentialism can bring the best and the worst out of people.

MRI Radiation – Dangers & Benefits

Magnetic resonance imaging (MRI) is a new technology for making images of the brain and other parts of the body. The technique depends on detection of a phenomenon called nuclear magnetic resonance, and also sometimes called NMR scanning. The discovery and development of MRI imaging is one of the most spectacular and successful events in the history of medical imaging. The nuclei of some atoms in the body are composed of numbers of nuclear particles. Such nuclei can be detected by sending weak energy signals through very strong magnetic fields. The MRI machine consists of a set of powerful magnets and a source of energy in the same general range used for broadcasting radio. The radio signal is affected in predictable ways by the number of odd-numbered nuclei in its path (Oldendorf; Boller, Grafman and Robertson). The MRI Procedure The MRI contains the massive main magnet, which is always on. The unit structure is approximately six or seven feet high and equally wide. As a patient, you will lie on your back on a special table that slides into the magnet through a two-foot-wide tunnel in the middle of the machine. Whether you go in head or feet first depends on the tissue being imaged. Be prepares for a loud knocking noise; this is not a silent machine. The loud knocking noise is caused by the gradients (small magnets) expanding against the supporting brackets. The MRI scanner will able to pick out voxels (three-dimensional cubes) maybe only one millimeter on each side. It will make a two-dimensional or three-dimensional map of tissue type. The computer will integrate this information and create two dimensional images (the usual) or three-dimensional models. The whole procedure takes from 30-60 minutes (Moe). Advantages and Disadvantages Due to the nature of the magnetic probe used in MRI, this technique possesses several fundamental advantages: 1) tissue can be characterized in a number of ways, 2) any plane can be imaged 3) bone is invisible, so all anatomic regions can be examined, and harper images are produced 4) no contrast medium is required and 5) there is no ionizing radiation, which makes it safe for children and for repeated scanning of the same person 6) the level of detailed exceeds the detail of other imaging techniques. At the present time, there are also several disadvantages 1) he complexity and high cost 2) the long scan time, 3) the noise isolation experienced by patient during scan and 4) the exclusion of substantial fraction of patients dues to pacemakers, metallic artifacts, and inability to cooperate. Furthermore, magnetic strength can be a dangerous thing. Stories abound the magnet’s power to pull metal objects (such as paper clips, keys, scissors, stethoscopes, IV poles, and even oxygen tanks) toward the patient and into the machine. Even worse, accidents have occurred with metal inside a patient. After an MRI, a metal worker went blind because the magnet moved microscopic metal particles in his eyes, damaging their surrounding structures. A survivor of and aneurysm died during an MRI because the magnet tore off the metal clips holding together a blood vessel in her brain, causing her to bleed to death. The patient must stay absolutely motionless during the procedure. (Minor motion does not have as much impact on a CT scan.) Therefore, a sedative is often necessary for a child having an MRI scan. The first three of these are under active development, and improvement can be expected. However, gradient coil noise, pacemakers and metallic artifacts are more fundamental problems for which solutions are not yet apparent (Stergiopoulos). MRI in association with CT Magnetic resonance imaging is another method for displaying anatomy in the axial, sagittal, and coronal planes. The slice thickness of the images vary between 1 and 10 mm. MRI is especially good for coronal and sagittal imaging, whereas axial imaging is the forte of CT. One of the main strengths of MRI is its ability to detect small changes (contrast) within soft tissues, and MRI soft tissue contrast is better than that found in CT images and radiographs. CT and MR imaging modalities are digital-cased technologies that require computers to convert digital information to shades of black, white and gray. The major difference in the two technologies is that in MRI the patient is exposed o external magnetic fields and radio frequency waves, whereas the patient is exposed to x-rays during a CT study. The magnetic fields used in MRI are believed to be harmless. MR scanning can be a problem for people who are prone to develop claustrophobia because they are surrounded by a tunnel-like structure for approximately 30-45 minutes. The external appearance of an MRI scanner or machine is similar to a CT scanner with the exception that the opening is the MR gantry is more tunnel-like. As in CT, the patient is comfortably positioned supine, prone, or decubitus on a couch. The couch moves only when examining the extremities. The patient hears and feels a jackhammer-like thumping while the study is in progress. The underlying physics of MRI is complicated and strange-sounding terms proliferate. Let’s keep it simple: MRI is essentially the imaging of protons. The most commonly imaged proton is hydrogen, as it is abundant in the human body and is easily manipulated by a magnetic field. However other nuclei can be imaged. Because the hydrogen proton has a positive charge and is constantly spinning at a fixed frequency, called the spin frequency, a small magnetic field with a north and south pole surrounds the proton. Remember that moving charged particles creates a surrounding magnetic field. Thus, these hydrogen protons act like magnets and align themselves within an external magnetic field or the needle of a compass. In the MR scanner, or magnet, short bursts of radio frequency waves are broadcast into the patient from radio transmitters. The broadcast radio wave frequency is the same as the spin frequency of the proton being imaged (hydrogen in this case). The hydrogen protons absorb the broadcast radio wave energy and become energized, or resonate. Hence, the term magnetic resonance. Once the radio-frequency wave broadcast is discontinued, the protons revert or decay back to their normal or steady state that existed prior to the radio wave broadcast. As the hydrogen protons decay back to their normal state or relax, they continue to resonate and broadcast radio waves that can be detected by a radio wave receiver set to the same frequency as the broadcast waves and the hydrogen proton spin frequency. The intensity of the radio wave signal detected by the receiver coil indicates the numbers and locations of the resonating hydrogen protons. Although human anatomy is always the same no matter what the imaging modality, the appearances of anatomic structures are very different on MR and CT images. Sometimes it is difficult for the beginner to differentiate between a CT and an MR image. The secret is to look to the fat. If the subcutaneous fat is black, it is a CT image as fat appears black on studies that use x-rays. If the subcutaneous fat is white (high-intensity signal), then it has to be an MR. next, look to the bones. Bones should have a gray medullary canal and a white cortex on radiographs and CT images. The medullary canal contains bone marrow, and the gray is due to the large amount of fat in bone marrow. On a MR image, nearly all of the bone appears homogenously white as the bone marrow is fat that emits a high-intensity signal and appears white. Also, on MR the cortex of the bone will appear black (dark or low intensity signal), whereas on CT images the cortex is white. Soft tissues and organs appear as shades of gray on CT and MR. Air appears black on CT and MR. air appears black on CT and has a low-intensity signal (black or dark) on MR (Moe). Intraoperative MRI At present, MRI is, by far, the most useful imaging modality for visualizing intracerebral tumors. It provides the most clear, detailed, and comprehensive diagnostic information regarding the tumor ad surrounding normal structures. The introduction of MRI and image-guided technology into the operating room thus allows the surgeon to use high-quality, current image data that reflect the surgical reality of brain tissue deformations and shifts that occur after the bone flap has been turned, the dura opened, and the resection begun. Today’s intraoperative MRI systems can be classified into two main groups: 1) the high field strength systems and 2) the low compact systems. Both types of systems have advantages and disadvantages. The high-field strength systems (0.5-1.5 T) are typically mounted on a stationary gantry and have gradient capabilities sufficient to produce full head images of quality comparable to that of diagnostic MRI. Magnetic resonance imaging can satisfy these requirements for therapy. It has excellent anatomic resolution for targeting, high sensitivity for localizing tumors, and temperature sensitivity for online treatment monitoring. Several MRI parameters are temperature sensitive; the one based on the proton resonance frequency allows relatively small temperature elevations to be detected prior to any irreversible tissue damage. Thus, the location of the focus can be detected at relatively low powers, and the accuracy of targeting can be verified. In addition, using calibrated temperature-sensitive MRI sequences, focal temperature elevations and effective thermal doses may be estimated. Such thermal quantification allows for online feedback to ensure that the treatment is safe, by assuring that the focal heating is confined to the target volume and below the level for boiling. Thermal assessment predicts effectiveness by assuring that the temperature history is sufficient to ensure thermal coagulation (Moore and Zouridakis). Conclusion Since the first availability of commercial instruments at the beginning of the 1980s, clinical MR has expanded rapidly in terms of both medical applications and the number of units installed. First considered to be expensive method to create images of inferior quality, it has since established itself as a clinical tool for diagnosis in previously inconceivable applications, and the potential of the method is still not exhausted. MRI has led to the first-scale industrial application of superconductivity and has brought about a grater public awareness of a physical effect previously known only to a handful of scientists. Up to now, the growth and spectrum of applications of MR have exceeded all predictions. The most recent development is that of rendering brain functions visible. Cardiac MR can display coronaries and analyze perfusion of the myocardium and hemodynamics of the heart. Thus, MRI is entering the domain of nuclear medicine. An interesting new application of MRI is its use as an imaging modality during minimal invasive procedures such as ablation, interstitial laser therapy, or high intensity focused ultrasound. With temperature-sensitive sequences, the development of temperature and tissue damage can be checked during heating and destroying of diseased tissue. The sensitivity of MRI to flow helps the physician to stay away from vessels during an intervention. MRI is also used for image-guided surgery, e.g., resection of tumors in the brain. Special open systems have been designed for such purposes, and dedicated non magnetic surgery tools have already been developed (Erkonen and Smith). Works Cited: Boller, Franà §ois, Jordan Grafman, and Ian H. Robertson. Handbook of Neuropsychology. Vol. 9. New York: Elsevier Health Sciences, 2003. Erkonen, William E., and Wilbur L. Smith. Radiology 101: The Basics and Fundamentals of Imaging. 2nd ed. New York: Lippincott Williams & Wilkins, 2004. Moe, Barbara A. The Revolution in Medical Imaging. New York: The Rosen Publishing Group, 2003. Moore, James E., and George Zouridakis. Biomedical Technology and Devices Handbook. New York: CRC Press, 2004. Oldendorf, William. Basics of Magnetic Resonance Imaging. Boston: Springer, 1988. Stergiopoulos, Stergios. Advanced Signal Processing Handbook: Theory and Implementation for Radar †¦ New York: CRC Press, 2001.      

FOSS Research Assignment Essay

FOSS (Free and Open Source Software) had some trouble in 2006 when Microsoft submitted 235 patents that were allegedly violated by FOSS. Microsoft created these patents in order to collect royalties from companies in the â€Å"free world† (companies/people using free software). Eben Moglen of the Free Software Foundation contended that software is a mathematical algorithm and is not patentable. Moglen wrote, â€Å"It’s a tinderbox. As the commercial confrontation between free software and software-that’s-a-product becomes more fierce, patent law’s going to be the terrain on which a big piece of the war’s going to be fought.† FOSS has powerful corporate patrons and allies. So if Microsoft ever tried to sue Linux distributor Red Hat for patent infringement, for instance, OIN might sue Microsoft in retaliation, trying to enjoin distribution of Windows. In the 1970s and 1980s, software companies relied mainly on â€Å"trade secrets† doctrine and copyright law to protect their products. But everything changed in the 1990s. The copyright law was providing less protection to software than companies hoped for and the â€Å"trade secrets† doctrine was becoming unworkable because the secret itself (the source code) had to be revealed to an unlimited number of other people/companies. With the internet, Microsoft applied for 1,411 patents in 2002. By 2004 they submitted 3,780 patents. After that Microsoft had three choices. First they could do nothing and donate the patents to the development community. Second they could start suing other companies that were using their patents. Or third, they could begin licensing its patents to other companies for either royalties or access to their patents, which would be a cross-licensing deal. So they took the third option. Microsoft later made a deal with Novell. They agreed not to sue each other’s customers for patent infringement, which is okay because it’s something that Richard Stallman’s GPL doesn’t address. Novell then agreed to give MS a percentage of all its Linux revenue through 2011. Microsoft decided it would pay Novell $240 million for â€Å"coupons† that could sell to customers, who would then trade in the coupons for subscriptions to Novell’s Linux server software. They also paid a â€Å"balancing payment† for the patent part of the deal. So now all of the FOSS developers are in fear because â€Å"the big boys† aka MS could purchase their version of Linux through a vendor such as Novell while getting protection from lawsuits and letting the â€Å"little guys† to fend for themselves. But without the little guy developers, the future of high-quality FOSS is undetermined. So the Free Software Foundation drafted a new version of the GPL that would prevent anyone else from using the original copy’s loophole that MS exploited. But Moglen had another thought. The fact that MS was selling coupons that people/companies could trade in for Novell subscriptions meant that MS was now a Linux distributer and went against the terms of the GPL, and was in fact in violation themselves. So Moglen wrote that if MS continued to issue these coupons after the new GPL takes effect, it would be waiving its right to bring patent suits against all Linux users. Moglen kept his promise and the new version of the GPL was released that July. Microsoft and Novell proceeded with their deal. But Moglen’s revisions will prevent other companies from making any more deals like the Novell one. Microsoft hoped that the deal with Novell would be a model it could use it to collect royalties with other companies of free software. So the bridge from MS to FOSS failed, but we are now closer than ever to â€Å"patent Armageddon.† The bridge with MS needs to be burned and the patent system needs to be shut down. Moglen says â€Å"The free world says that software is the embodiment of knowledge about technology, which needs to be free in the same way that mathematics is free. Everybody is allowed to know as much of it as he wants, regardless of whether he can pay for it, and everybody can contribute and everybody can share.† Works Cited Article: â€Å"Microsoft takes on the free world† Link: http://money.cnn.com/magazines/fortune/fortune_archive/2007/05/28/100033867/index2.htm