Construction of the Space Colony: Challenges

Construction of the Space Colony: Challenges Construction The major problem regarding such a big and aspiring project is trying to reflect the imagined side of it into reality. Until now, this problem has been a rather unsolvable one, but with the modern day possibility of colonizing close to Earth celestial entities, like the Moon, and to rapidly create parts with 3D printers, it is possible to overcome it. The construction of the space colony has been a rather debated dilemma, being a very sensible issue, which regards huge amounts of funding and involvement. There have been issued 3 construction plans, which we will analyze and show the disadvantages of two of them, and the perks of the one I have chosen: 1. Terrestrial construction before the rapid development of space shuttles and the advanced repairing of satellites in space (a rather common action in modern times), the only solution, which seemed possible for the construction of such a project was building it as a whole on Earth. Even if it were more facile and faster regarding the actual construction process, shipping it on the orbit would be an impossible action. That amount of mass requires the usage of fuel of almost 4800 launchings, which will only increase the weight of the station and reduce the force to mass ratio of the engines used. Also, in order to generate that amount of force, to defy the gravitational pull, it would be required an incredible amount of energy, which is the equivalent of a handful of atomic detonations. The consequences for the environment would be horrific, if we succeed in lifting the station of the Earth, a very doubtful presumption. 2. Outer-space construction the safest bet for the construction plan of the station was, until now, an extra planetary building area. After realizing the fact that it would be impossible for any human engine to lift the station from Earth, it became clearly that, in order to have a functional construction plan, the station must be built on an orbit of our planet. With the present development of orbiting satellite repairs, the building of such an immense project seems actually achievable. The problem regarding this solution is represented by the fact that, besides the great difficulty of building such a complex architectural creation in a harsh, unfriendly environment, the actual process of the construction would take a huge amount of time to be accomplished. Also, the weak point of outer-space construction is the fact that it depends on terrestrial resources and on shipments from Earth. Because of the fact that a normal shuttle can normally carry, besides the crew, a weight of a sat ellite, there would be required over 6000 flights in order to bring all the materials and tools in outer-space. A normal ship can be used for about 10 space missions, so it would also require over 600 space shuttles. By adding the whole process of building and shipping, including the price of the materials that are required to complete the station, which will substantially diminish the Earth resources and will become more expensive by every transport, it has been estimated that the total cost of the station would be of 6023 trillion dollars, a sum which does not exist in the whole modern day economic system. 3. Moon construction after identifying the problems that outer-space construction has, mostly the fact that it does not present reliability, the Carpathia team decided that the best answer for the construction problem would be a celestial entity that has solid ground, but does not have a gravitational pull as powerful as Earths, and is closer to the orbit in which the future station will be placed. In other words, escape velocity here is much lower than on Earth and, so, breaking free from the gravitational attraction of the moon requires less energy and a lower speed (due to the fact that the gravitational constant is lower). Also, the location should have materials that can be mined and used in the construction of the station. The most suitable place, which met all the requirements from above, is represented by Earths natural satellite, the Moon. This project requires two major steps, first one being the colonization of the Moon with mining bases, that can gather resources which will be equipped with huge 3D printers in order to create the ships components, and the second one being the construction of the ship and its positioning in L4 Lagrange Point. Even if it may seem a far-fetched idea, colonizing the Moon with the modern day technology like remote control robots and printers that are able to receive information through radio waves at the speed of light is a reachable goal. The process will start with sending huge two-part mining robots with 10 space missions that will be assembled by the crew, having 5 mining machines. Also, they can be programmed to process the materials on spot into liquid metal, which will be used by the printers in order to create the parts. The 3D printers, being enormous machines, will be also sent in two missions, being assembled on the spot. After having the raw materials, established on the Moon, there will also be sent 10 shuttles, each carrying 10 robot workers, very versatile machines that can wield, cut and grab any form, and can also receive complex commands, like group commands in order to build major components, other mining machines or 3D printers to supplement the output of materials. All of the 3 types of machines will be solar powered, and will be controlled from a command-center on Earth. While the 3D printers will receive models of components and the number of copies needed, the mining robots will be fully controlled by a human being to avoid the risk of mistake. Using programming style similar to the one of the nabobs, the robotic workers will be issued a command and will have autonomy in fulfilling it. After the process of building the station has already started, we would be sent 20 more missions with 20 workers each to start and build the final station, which will be colonized with 11500 residents when completed. The station is made from sections (major and minor components) that will be each explained in their own chapter. Carpathia is being made mainly from carbon nanotubes which will be shaped into the form of 8 cylinders, being: Central Area, Lower and Upper Industry, Agriculture Area, Habitable Area, Animal Area and final Maintenance Zone. The solar panels as well as the computers and refined cables will be brought from Earth with the Space Elevator, not having necessary materials on the Moon to build them. Also, the engines required to maintain the spinning of the ship will be assembled on Earth and sent on the Moon by a space mission.   The second step, after the construction of the ship, will be moving it towards its final position. For this task, we will be using the engines that assure the rotation of the ship, by shifting them downwards and achieving Moon liftoff. We will then orientate the engines in order to use them as thrusters and send the space colony into the L4 Lagrange point. In conclusion, it can be safely said that, even if it involves a huge deal of resources and time, the Moon constructing solution is the most feasible one from all the other solution presented above, being more realistic than the terrestrial construction, and less costly than the outer-space construction.

Religious and Architectural Sites of Florence Essay examples -- Archit

Religious and Architectural Sites of Florence According to the United Nations Educational, Scientific and Cultural Organization, Italy is home to some 60 percent of the world?s most famous works of art.? Of these, one-half are found in Florence (19).? Florence gained most of this collection during the fifteenth century, when the Florentines decided to move back from Gothic fashion to the more Romanesque style of art and architecture.? This return to the Classic style is known as the Renaissance, and Florence was its birthplace.? Renaissance artists prospered greatly on account of the financial support they received from wealthy citizens (such as the Medici family) and the church, which purchased numerous works of art (6).? Further, the Florentines were a people of great civic pride, and found a means of expressing that pride through awe-inspiring monuments and statues of their patron saints (13).? With the will and the means, Florence became the home of many impressive works that have lasted to-date.? In regards to its architecture, Florence was built over many years, being founded as a Roman colony in the first century BC (4).? It is therefore home to many buildings of Romanesque and Gothic style (6).? With the arrival of the Renaissance, buildings were made again in the classic style, which leads to the city?s diversity in architecture.? Similarly, ?many Florentine structures that outwardly exemplify architecture from earlier times also house interiors, typical of the renaissance? (6).? Illustrations of such changes can be seen among those buildings whose construction spanned the time when Florentines shifted from Gothic back to the Classical style. Santa Maria Del Fiore: One such example is Florenc... ...om/eb/article?eu=67262> 15.?The Baptistry?.? Vivifirenze.? 15 Nov. 2003 ? 16.?The Cathedral?.? Vivifirenze.? 15 Nov. 2003 17.?The Duomo and the Baptistry.? Vivifirenze.? 22 Nov. 2003 18.Weinberger, Martin.? Michelangelo the Sculptor.? New York: Columbia University Press, 1967. 19.Wright-Martin, Linda.? ?Florence ? Art Capital of Italy?.? Italy for Visitors.? 2 Nov. 2003 Sienna, original? Final Bell Tower.? Terrace by Francesco Talenti drawing of the Bell Tower. Source (8) Basilica di San Francesco, Assisi (http://www.bellaumbria.net/Assisi/san_francesco.htm) Giotto?s Tower at the Duomo (Furman, Spring 2000). Source:? (7)

Algebraic expressions.Elementary and Intermediate Algebra Essay

Algebraic expressions Introduction   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   In the introduction to Algebra, the first assignment for the first week will involve using real numbers in place of integers to simplify expressions. Everyone needs to take his/her time to grasp the rules and the steps which are followed in algebra as this will form a concrete base for the algebraic expression understanding. One needs to understand the mathematical fundamental elements so as not to incur problems in solving any algebraic problems. For instance, one needs to be clear with the properties of integers as these are the same properties which apply to the real numbers. The first step in dealing with equations is removing the parenthesis. If an equation requires you remove the parenthesis from the equation, distribution becomes a necessity. Like terms should be grouped together when multiplying the integers that are inside the parenthesis to perform any indicated operation (Dugopolski, M.(2012  ), 2, p.67).   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   The following is how I attempted to handle the assigned equations in the simplest form. In the left side of the page, I have put the mathematic equation, and in the right side there is my explanation of the steps I followed. 2a(a-5)+4(a-5) Equation =2a ²-10a+4a-20 remove the distributive properties from the parenthesis = 2a ² -6a-20 then we get the coefficient. =a ²- 3a – 10 then we simplify the expression. In the next equation, 2.  2w-3+3(w-4)-5(w-6) the equation =2w-3+3w-12-5w+30   remove the distributive properties from the parenthesis =2w+3w-5w-3-12+30 then we get the coefficients and. =15 combine them In the third equation, 3. 0.05(0.3m+35n)-0.8(-0.09n-22m) the equation =0.015m+1.75n+0.072n+17.6m remove the distributive property from the parenthesis =0.015m+17.6m+1.75n+0.072n simplify by putting the like terms together and =17.615m+1.822n combine them References Dugopolski, M. (2012  ). Elementary and Intermediate Algebra. New York, NY: McGraw-Hill. Source document

Free Essays on The Concious Of A Man

The Conscious of a Man The cruelty of war, the power of an alliance and the honor of a man are vividly described in Hernado Tellez short essay â€Å"Just Lather, That All†. In This short fiction story/essay Tellez tells a story that seems to real. It is almost as if he was describing what is going on today in Central and Southern American countries, such as Colombia. His story/essay is about one man who is caught in a dilemma during an encounter with his enemy. The dilemma of this man is his own conscious. It is strange how one mans conscious can go trough so many things, such as contradicting and asserting itself. And in this story/essay this occurs a lot as most of the story/essay is told from the conscious of the character. The character/man is a local barber who has great pride on his work, which is captured in a quote from pg. 700: â€Å"I am a good barber, the best in town, if I may say so†. He is also part of an alliance of rebels The dilemma of the barber starts when a Military group enters his work. The group is a team of soldiers whom haunts and kills rebels; and at the top of this group is a Captain named Torrez. Captain Torrez is a men who has a really bad image, he is painted in such a way that he resembles Fidel Castro in a line from pg. 699: â€Å"†¦he took off the bullet-studded belt that his gun holster dangled from. He hung it up on a wall hook and placed his military cap over it†. The barber is not pleased at all with this man being at his work â€Å"Damn him for coming because I’m a revolutionary†¦Ã¢â‚¬ (pg.701). The first thing that crosses the barber’s conscious is to kill the captain or to not kill the captain. This question in his mind is what begins the entire dilemma. He had never had the captain so close to him and it was not known that he was a revel. But the barber knew one thing from the beginning; Torrez was a customer in his shop and not an enemy. This is clear through the entire story... Free Essays on The Concious Of A Man Free Essays on The Concious Of A Man The Conscious of a Man The cruelty of war, the power of an alliance and the honor of a man are vividly described in Hernado Tellez short essay â€Å"Just Lather, That All†. In This short fiction story/essay Tellez tells a story that seems to real. It is almost as if he was describing what is going on today in Central and Southern American countries, such as Colombia. His story/essay is about one man who is caught in a dilemma during an encounter with his enemy. The dilemma of this man is his own conscious. It is strange how one mans conscious can go trough so many things, such as contradicting and asserting itself. And in this story/essay this occurs a lot as most of the story/essay is told from the conscious of the character. The character/man is a local barber who has great pride on his work, which is captured in a quote from pg. 700: â€Å"I am a good barber, the best in town, if I may say so†. He is also part of an alliance of rebels The dilemma of the barber starts when a Military group enters his work. The group is a team of soldiers whom haunts and kills rebels; and at the top of this group is a Captain named Torrez. Captain Torrez is a men who has a really bad image, he is painted in such a way that he resembles Fidel Castro in a line from pg. 699: â€Å"†¦he took off the bullet-studded belt that his gun holster dangled from. He hung it up on a wall hook and placed his military cap over it†. The barber is not pleased at all with this man being at his work â€Å"Damn him for coming because I’m a revolutionary†¦Ã¢â‚¬ (pg.701). The first thing that crosses the barber’s conscious is to kill the captain or to not kill the captain. This question in his mind is what begins the entire dilemma. He had never had the captain so close to him and it was not known that he was a revel. But the barber knew one thing from the beginning; Torrez was a customer in his shop and not an enemy. This is clear through the entire story...

Critical Study of the Aetiology and Pathogenesis of Infantile Glaucoma The WritePass Journal

Critical Study of the Aetiology and Pathogenesis of Infantile Glaucoma Introduction Critical Study of the Aetiology and Pathogenesis of Infantile Glaucoma IntroductionEpidemiology of Primary Infantile Glaucoma Signs, Symptoms and Consequences of Primary Infantile GlaucomaPathology, Pathogeneses and Causes of Primary Infantile GlaucomaOptic Cup Asymmetry in Primary Infantile Glaucoma Secondary infantile glaucomaReferencesRelated Introduction The incidence of glaucoma in the young population is incomparable to the incidence in the adult population, as it is very rare in infants, nevertheless it can significantly affect a child’s life, as vision is vital for a young child. Signs and symptoms of infantile glaucoma can commonly be overlooked and this can cause a delay to the treatment process. The underlying causes of infantile glaucoma have been agreed upon by most authors, however the exact mechanism by which the structures in the young eye are affected are debatable. As well as primary infantile glaucoma, young children can also be affected by secondary infantile glaucoma, which again can significantly impact a young child’s life. This paper looks at the classifications, epidemiology, signs, symptoms, aetiology and pathogenesis of primary infantile glaucoma, as well as touching upon the causes of secondary infantile glaucoma. ‘Glaucoma is an Optic neuropathy with characteristic appearances of the optic disc and specific pattern of visual field defects that is associated frequently but not variably with raised intra-ocular pressure (IOP)’ (Kanski, 2003). The ciliary processes of the eye produce aqueous humor; this is then drained by the trabecular meshwork; Figure 1. A balance of this production and drainage maintains a normal IOP. The aqueous humor produced flows into the posterior chamber, then through the pupil and into the anterior chamber. The trabecular meshwork drains the aqueous humor through Schlemm’s canal. Open angle glaucoma occurs when there is a decrease in the outflow of aqueous through the trabecular meshwork, and angle closure glaucoma occurs when the iris adheres to the lens leading to a build-up of aqueous humor in the posterior chamber   (Kanski, 2003). In addition to open and closed angle glaucoma there are other types of glaucoma which are classified in Figure 2. There are several classifications of congenital and infantile glaucomas, the most accepted and simplified version is presented in figure 3. Primary infantile glaucoma is defined as ‘the result of isolated abnormal development of the anterior chamber angle structures’ (Myron Yanoff, 2009) Secondary infantile glaucomas are ‘associated with a variety of ocular and systemic syndromes and with surgical aphakia’ (Myron Yanoff, 2009). Primary congenital glaucoma is present at birth however it is not always recognised at this stage and sometimes it is diagnosed later during infancy or in early childhood. To minimise problematic visual development, recognition of primary congenital glaucoma must be as early as possible followed by respective treatment or therapy, allowing the child to lead a ‘normal’ life (A.Armstrong, 2008). Glaucoma in infants and young children is relatively rare and in some cases asymptomatic (Kanski, 2003). And so, if an increase in IOP is not detected at an early stage then there is a greater risk of blindness (Robert N. Shaffer, 1970). Some cases of glaucoma in infants are only recognised and diagnosed after several months or years at which stage sometimes significant glaucomatous damage has already occurred (Robert N. Shaffer, 1970). Most cases will present bilaterally nevertheless this does not rule out the fact that it can sometimes present unilaterally   (Robert N. Shaffer, 1970). Epidemiology of Primary Infantile Glaucoma Primary infantile glaucoma is extremely rare and occurs in one out of 10,000 births (MillerSJ, 1966). It accounts for 0.01% to 0.04% of cases of total blindness (A.Armstrong, 2008) (Vincent P Deluise, 1983) In the Irish childhood population primary open angle glaucoma is the cause of blindness for 4% of the population. (Morin JD, 1974) The majority of cases in the US and Europe present with bilateral primary infantile glaucoma; 65%-80% (Moller, 1977). It is also well-known that it occurs greater in males compared to females with a ratio of 3:2 respectively (Vincent P Deluise, 1983). This is proven by a study with 125 infants from Westerlund, 76 of whom were male i.e. nearly 61% were males (Vincent P Deluise, 1983). On the other hand in Japan, this is no longer true and the ratio is actually reversed (Vincent P Deluise, 1983). In another study based in Japan out of 46 children with primary infantile glaucoma 63% were actually female (Vincent P Deluise, 1983). In the majority of cases the development of primary infantile glaucoma is found to sporadic, and so it is non-familial and nonhereditary, but approximately 10% of cases are familial, transmitted to the child via autosomal recessive inheritance (Vincent P Deluise, 1983). Signs, Symptoms and Consequences of Primary Infantile Glaucoma Children are commonly referred to the Ophthalmologist due to clinical evidence of corneal oedema. Primary infantile glaucoma is commonly misdiagnosed, hence causing a delay in the correct diagnosis, as it may initially show symptoms similar to conjunctivitis such as a ‘red eye’ (Becker B, 1965). There will also be evidence of the classic triage; epiphora, blepharospasm and photophobia. (Becker B, 1965). Further examination will reveal megalocornea (enlarged corneal diameter), buphthalmos (enlarged globe), Haab’s striae (breaks in Descemet’s membrane) and optic nerve head changes (Becker B, 1965). Buphthalmos; figure 4, or ocular enlargement, occurs in primary infantile glaucoma because the globe of neonates is still distensible (Vincent P Deluise, 1983). Collagen of the cornea and scleral have not hardened enough, so expansion of the fibrils occurs due to an increase in IOP (Vincent P Deluise, 1983). This therefore causes stretching to occur in several structures of the infant eye; such as the cornea, the anterior chamber angle, the sclera, the optic nerve, scleral canal and the lamina cribrosa (Becker B, 1965). This explains why ocular enlargement due to glaucoma does not occur in adults, as the globe is no longer distensible and collagen fibres of the cornea are sclera are hardened hence expansion doesn’t occur in adults. It is agreed that delayed therapy of infants with glaucoma, will result in a poor visual outcome for the infant, which could have been prevented or at least minimised. To understand why some infants had more advanced glaucoma than others; a study with 24 infants and children was conducted (David J. Seidman MD1, 3 March 1986). Their signs and symptoms were noted. The parents of the infant were asked to indicate whether they had noticed either epiphora or photophobia and only 32% said their infant had these symptoms. A small 21% of infants presented with only signs of glaucoma, noticed by the parents but no symptoms. And finally the majority of infants, 90%, actually did have signs when presenting to the physician. It has been noted that signs of infantile glaucoma are more difficult to notice when it is bilateral, as in all 3 cases where the physicians failed several times to refer the infant to an ophthalmologist the glaucoma was in fact bilateral   (David J. Seidman MD1, 3 March 1 986). A normal value for the corneal diameter of a neonate is approximately 10mm, an increase to 12mm or greater, along with expansion of the corneal-scleral junction, is usually due to increased IOP (Kwitko, 1973). Enlargement of the cornea due to an increase in IOP is most likely to occur up to the age of three (Scheie, 1955) after which the sclera may become deformed up to age ten (Mann, 1957). Breaks occur in the endothelium and Descemet’s membrane due to the increase in IOP which also causes stretching in these layers (Vincent P Deluise, 1983).   ‘Haab’s striae form as endothelial cells lay down new basements membrane (Descemet’s membrane) and hyaline ridges develop. Breaks in Descemet’s membrane from increased IOP rarely occur after age three’ (Vincent P Deluise, 1983).   Increased IOP also causes slow expansion of the sclera of the neonate. A ‘bluish’ scleral appearance is seen due to thinning of the sclera, causing the choro id to be more apparent (Vincent P Deluise, 1983). As the neonate becomes older and growth occurs the expansion of the sclera no longer occurs due to a build-up of extracellular connective tissue (Vincent P Deluise, 1983). Even if the IOP decreases back to a value within normal the globe does not usually return to normal size (Vincent P Deluise, 1983). Studies have shown that myopia and astigmatism are the consequence of an increase in the axial length of the globe, figure 5 (Robin AL, 1979). Robin et al also found that ‘In contrast to adult eyes, the scleral canal in children apparently enlarges with high IOP. Thus, disk cup size increase in children could occur from neural tissue loss, from scleral canal enlargement, or from a combination of the two processes’ (Robin AL, 1979). ‘Myopic astigmatism and anisometropia are particularly common in cases of unilateral or asymmetric primary infantile glaucoma’ (Vincent P Deluise, 1983).   A study carried out by Broughton and Parks found that all of their patients with unilateral primary infantile glaucoma had anisometropia; on the affected side an average difference of 4.93D of myopia was found (Broughton WL, 1981 May). Optic nerve changes which occur in adults with glaucoma are very different to the optic nerve changes which occur in children with glaucoma. At first Becker Shaffer initially thought that cupping in primary infantile glaucoma was a process which was gradual however it was soon discovered that optic nerve changes in primary infantile glaucoma could also occur early and rapidly (Becker B, 1965). In adults with optic nerve changes which occur due to an increase in IOP the change is very unlikely to be reversible, however in infants optic nerve cupping which occurs due to an increase in IOP can be reversed once the IOP is returned back to normal (Vincent P Deluise, 1983). The most accepted and most reasonable hypothesis which aims to explain why cupping is reversible in neonates is based on the fact that the connective tissue of the lamina cribrosa is not matured (Quigley, 1977 Sep). However there are cases when even though the pressure has decreased back to normal the Optic nerve head damage does not reverse, this is due to one of two reasons. Firstly it is possible that some of the stretching is permanent ‘with remoulding of the connective tissue’   (Vincent P Deluise, 1983). Secondly it could be due to ‘a loss of glial and axons’ (Vincent P Deluise, 1983).   ‘Adult optic nerve heads with their dense connective tissue investments are more resistant to remoulding, indicating that cupping is caused by permanent loss of glia and axons’ (Vincent P Deluise, 1983). Pathology, Pathogeneses and Causes of Primary Infantile Glaucoma The explanation for the increase in IOP in primary infantile glaucoma has been described using Barkan’s membrane theory. This theory is based on the fact that the anterior chamber angle is covered by a thin and imperforate membrane, which inhibits aqueous outflow, which in turn leads to raised IOP (Vincent P Deluise, 1983). According to the theory, this raised IOP is treated by goniotomy when the surface tissue of this membrane is detached, and so â€Å"the peripheral iris falls posteriorly,† subsequently there is aqueous outflow and a decrease in IOP (Vincent P Deluise, 1983). Worst also agreed with the Barkan membrane theory, â€Å"†¦in congenital glaucoma the chamber angle is filled with a band of persistent mesodermal tissue (persistent uveal meshwork or persistent pectinate ligament). This tissue completely covers the fetal corneoscleral system, but is not the cause of the obstruction to aqueous outflow in its own right. It is the presence of an imperforate surface layer on this persistent mesodermal tissue, which is the only cause of obstructed outflow. This surface membrane, Barkans membrane, is probably an endothelial surface, which normally breaks apart, but which persists in congenital glaucoma† (Worst, April 1968). There is no well supported histopathologic evidence to support Barkan’s membrane theory, despite this Worst still believes that the theory along with its concepts are valid, he says â€Å"though histopathologic proof of this structure is almost completely lacking†¦this has little influence on the probability th at this concept is valid† (Worst, April 1968). So if Barkan’s membrane theory has insufficient evidence to explain the cause of an increase in IOP in congenital glaucoma, then what is the alternative? There is some histopathologic evidence which aims to explain in detail the anterior chamber angle and its histopathology in infants with primary infantile glaucoma see Figure 6 (Vincent P Deluise, 1983). Anderson thoroughly researched the development of the trabecular meshwork in infantile glaucoma. He said that earlier thoughts were that â€Å"the anterior chamber recess deepens by atrophy of the rarified tissue that in the earlier stage separated the trabecular meshwork and ciliary body.† He then confirmed that later thoughts highlighted the function of cleavage into the loose tissue, as there was no proof of atrophy (D.R.Anderson, 1981). These views may have seemed correct at the time however, evidence has proven that cleavage or atrophy are not the only explanations of the process of development. Both cleavage and atrophy would cause the uveal tract to become fragmented from the shell of the cornea and sclera as well as the tissue of the trabeculae (Fig 7A) (D.R.Anderson, 1981). This would result in extension of the ciliary muscle to the peripheral iris and on the posterior surface of the peripheral iris would be the ciliary processes (D.R.Anderson, 1981). However this does not actually occur, in fact the ciliary muscle and the ciliary processes continue to adhere to the envelope of the cornea and sclera although compared to their earlier position they do become depressed (Fig 7B) (D.R.Anderson, 1981). Anderson found that there is an overlay of the ciliary muscle in particular the ciliary processes over the trabecular meshwork; however they are subsequently depressed behind the scleral spur (D.R.Anderson, 1981). He found that â€Å"This repositioning can be explained only by a posterior sliding of the uveal tissues in relation to the cornea and sclera, presumably due to a differential growth rate of the various tissue elements† (D.R.Anderson, 1981). He concluded that this course of repositioning was not simply due to the â€Å"sliding of the uveal tract along the inner side of the sclera. There is also a repositioning of the various layers within the uveal tract in relation to one another: initially the innermost muscle fibers have a position relatively more anterior than the outermost fibers† (D.R.Anderson, 1981) Anderson also found that compared to the ciliary muscle the ciliary processes are at first a lot more frontward, as time passes both become level behind the scleral spur and meshwork (D.R.Anderson, 1981). So, far it has been established that primary infantile glaucoma occurs because the anterior chamber does not develop normally. At what stage of development do these changes or lack of changes occur? It has been noted that at week twelve of development â€Å"a wedge shaped mass of mesenchyme can be identified at the anterior chamber angle i.e. at the junction of the papillary membrane and the lateral margins of the cornea. Within this wedge shaped portion of the tissue there is a row of small capillaries, which are lined with mesoderm-derived vascular endothelial cells† (A.Armstrong, 2008). At the beginning of the fifth month â€Å"early trabeculae are apparent separated by intervening spaces† (A.Armstrong, 2008) subsequently the capillaries fuse to form the canal of Schlemm, this is continuous with the collector channels as well as the scleral vessels (A.Armstrong, 2008). â€Å"The meshwork becomes specialised into inner uveal trabeculae, numerous intermediate layers of lamellar corneoscleral trabeculae, and a more loosely organised cribriform meshwork† (A.Armstrong, 2008). The inner surface of the meshwork is lined with cuboidal cells, perforations of these cells occur onwards from 15 weeks (A.Armstrong, 2008). Communication between the meshwork and the anterior chamber occur via these cuboidal cells (A.Armstrong, 2008). Between the sixth and ninth month development of the anterior chamber occurs (A.Armstrong, 2008). It presents â€Å"as a chink in the mesoderm between the iris root and the developing trabeculum. If the mesoderm does not entirely regres s in this region, an impervious layer may remain bridging the angle between the iris and the cornea and which impedes access of aqueous to the trabecular meshwork† (A.Armstrong, 2008). Figure 8: Comparision of optic cup asymmetry in normal infants with unilateral glaucoma infants. Taken from (Richardson, April 1968) Optic Cup Asymmetry in Primary Infantile Glaucoma It has been established that chronic open angle glaucoma is found to be bilateral and symmetrical to a certain extent, however some meticulous studies may find that there is somewhat of asymmetry in the cupping of the optic discs (Richardson, April 1968). Nevertheless the asymmetry of the discs can be used to diagnose early signs of glaucoma (Richardson, April 1968). Although optic disc cupping is assessed in infantile glaucoma it is not used as prominently compared to chronic open angle glaucoma (Richardson, April 1968). One of the reasons for this is due to the obvious fact that it is not as easy to conduct ophthalmoscopy in infants especially with added factors such as hazy corneas, miotic pupils (Richardson KT, 1966). It is also a common misconception that cupping in the optic nerve occurs at a very late stage and so it is no longer relevant to aid diagnosis (Richardson, April 1968). The opposite is actually true, as changes to the optic disc in infantile glaucoma occur relatively early on, hence valuable factor to aid prognosis (Shaffer.RN, 1967). To emphasise the importance of asymmetry of optic discs in infantile glaucoma compared to chronic glaucoma, the following study was conducted by Kenneth Richardson. Normal newborn infants, 96 hours old or less, were randomly chosen and their optic discs were assessed. Out of 468 it was found that only 11 infants had optic cup asymmetry, 2.3%; figure 8 (Richardson, April 1968). Similarly Snydacker found that out a random 500 adults only 15 had any sign of asymmetry, 3% (SyndackerD, 1964). Going back to the infants it was found that only 3 out of the 11 actually had marked asymmetry between their optic cups i.e. only 0.6%; figure 8 (Richardson, April 1968). A very different but much predicted result was found when Shaffer conducted a slightly different study (Shaffer.RN, 1967). 27 infants with unilateral glaucoma were assessed and it was found that 89% or 24 out of 27 had marked asymmetry; figure 8 (Shaffer.RN, 1967). In other infantile glaucoma studies Schaffer also found that 61% (52/85) patients had optic cups with a disc diameter greater than 1/3 in comparison to 2.6%(26/936) normal newborns who had optic cups with a disc diameter greater than 1/3 (Shaffer.RN, 1967). The above data provides vital evidence supporting the views that optic disc assessment in newborn infants is extremely important and any asymmetry in optic cupping is very significant as ‘normal’ infants are expected and likely to have symmetrical optic cups. Hence any asymmetry of cupping could be indicative of congenital glaucoma. Also it can be said that optic cupping assessment is of more importance in congenital glaucomas â€Å"since these cases are prone to follow a more asymmetrical course than adult glaucomas† (Richardson, April 1968). In order chronic glaucoma in order to be able to determine whether cupping is physiological or pathological the disc appearance must be tracked over many years. Whereas in newborns the cupping is expected to be symmetrical at birth therefore any asymmetry should be and can be picked up at birth (Richardson, April 1968). Secondary infantile glaucoma There are several causes of secondary infantile glaucoma, the most important is ocular trauma and this is due to the fact that ocular trauma is common in young infants. Blunt trauma to the eye causes compression of the globe which in turn leads to a temporary increase in IOP. When a blunt object hits the eye its cause indentation of the cornea, this then forces the aqueous humor â€Å"laterally against the anterior chambers angle structures and backwards against the iris and lens† (Robert N. Shaffer, 1970). Thereafter â€Å"in the anterior segment the iris sphincter ruptures† (Robert N. Shaffer, 1970) the ciliary body could become separated from the scleral spur or it may just be split or torn (Robert N. Shaffer, 1970). Likewise the trabecular meshwork may become ruptured, consequently leading to glaucoma (Robert N. Shaffer, 1970). Traumatic iritis is another cause of secondary glaucoma. Blunt ocular trauma can cause inflammatory cells and increase in proteins in the aqueous humor, in the early stages. These cells along with the protein molecules then cause obstruction of the trabecular meshwork. (Robert N. Shaffer, 1970) Oedema of the trabecular meshwork will also lead to resistance in the outflow of the aqueous. Even though there is an increase in the resistance of outflow, the IOP will remain within a normal range and in some cases it may actually be lower than normal because the blow will have caused depression of the ciliary body along with hyposecretion (Robert N. Shaffer, 1970). Anterior chamber haemorrhage (hyphema) occurs due to trauma or injury to the eye. Small haemorrhages are unlikely to clot, however large haemorrhages may fill the anterior chamber and cause compression of the meshwork which in turn leads to an acute increase in IOP (Robert N. Shaffer, 1970). Another cause of secondary glaucoma is recession of the anterior chamber angle. â€Å"A significant percentage of traumatic hyphemas results from a longitudinal cleavage of the ciliary body† (Robert N. Shaffer, 1970). A chain of damage reactions which occur to the trabecular meshwork following this will decrease the outflow and lead to glaucoma. Contusion cataract can be caused by blunt trauma. â€Å"If the cataract intumesces, a phacogenic pupillary block glaucoma may result. If the cataract becomes hypermature the lens cortex which is liquefied may leak into the anterior chamber†¦Ã¢â‚¬ , (Robert N. Shaffer, 1970) a macrophage response occurs and these cells then cause an increase in IOP as they block access of the aqueous to the trabecular meshwork. (Robert N. Shaffer, 1970) This is known as phacolytic glaucoma. Dislocation of the lens most likely occurs due to trauma, and if the lens after dislocation ends up in the anterior chamber then pupillary block glaucoma is l ikely (Robert N. Shaffer, 1970). Secondary glaucoma is usually the result of a laceration to the globe. A blunt blow, by a child’s fist, is often very serious as the smaller size of the fist does not allow the orbit to provide protection and the blow lands straight on the eye (Robert N. Shaffer, 1970). Intra-ocular foreign bodies can also cause glaucoma; particles which contain iron will oxidise and can be toxic to structures within the eye such as the trabecular meshwork (Robert N. Shaffer, 1970). Severe iritis can lead to glaucoma, and transient or chronic glaucoma can result from inflammation of the trabecular meshwork with increased resistance to outflow (Robert N. Shaffer, 1970).   Inflammation of the cornea can also cause secondary glaucoma, due to further inflammation of the meshwork leading to obstruction of the aqueous outflow (Robert N. Shaffer, 1970). It is well-known that glaucoma can be induced by steroids. An increase in IOP can be induced by prolonged use of topical steroids, in susceptible individuals. Ocular tumours uncommon in children, however if one is present it can sometimes lead to secondary glaucoma (Robert N. Shaffer, 1970). Retinoblastoma, a well-known and common tumour found in the young can also cause glaucoma. The tumour will invade the anterior chamber angle structures; iris and trabecular meshwork. There is a very strong link between prenatal rubella infection and glaucoma and it is now well agreed upon that prenatal rubella can in fact cause glaucoma. It is estimated that rubella infantile glaucoma occurs in 2-4% of children with congenital rubella syndrome (Robert N. Shaffer, 1970). It usually presents in the first six months of life and the symptoms are identical to those of primary congenital glaucoma; an enlarged oedematous cornea which is cloudy, a deep anterior chamber and the classic high IOP (Robert N. Shaffer, 1970). Clinically it is found to be almost impossible to distinguish rubella infantile glaucoma from primary congenital glaucoma (Robert N. Shaffer, 1970). In conclusion, it has been determined that although rare conditions both primary and secondary infantile glaucoma can significantly affect the life of a child. Hence examination of the optic discs at birth is vital to ensure that any asymmetry of optic cups is detected and the possibility of the newborn developing glaucoma is known immediately, as it has been proven that infants with glaucoma are significantly more likely to show asymmetry of optic cupping compared to ‘normal’ infants. If the glaucoma is not detected at birth it is vital that healthcare professionals are able to recognise the signs and symptoms of infantile glaucoma so it can be treated before any significant damage has occurred, as it has been proven that the majority of children present with all or some of the signs and symptoms of glaucoma yet they are either overlooked by the parents or misdiagnosed by clinicians. In relation to the pathogenesis of infantile glaucoma significant evidence or lack of has proven that Worst along with Barkan’s Membrane theory are no longer valid. Vital histopathologic evidence undermines the theory; in fact Anderson has provided substantial evidence to prove that repositioning, sliding, cleavage and atrophy play a significant role in the development of primary infantile glaucoma. Along with the histopathologic evidence it can be concluded that Anderson’s findings can be accepted. References A. Edward Maumenee, M. (1962). Further observations on the pathogenesis of congenital glaucoma. TR. AM. OPHTH J. SOC, VOl. 60, 140-162. A.Armstrong, R. (2008, December 12th). Congenital Glaucoma; The genetics of primary congenital glaucoma. Optometry Today, pp. 40-43. Becker B, S. R. (1965). Diagnosis and Therapy of the Glaucomas. St Louis: CV Mosby. Broughton WL, P. M. (1981 May). An analysis of treatment of congenital glaucoma by goniotomy. Am J Ophthalmol. , 91(5):566-72. Ching Lin Ho, F. a. (September/October 2004). Primary Congenital Glaucoma: 2004 Update. Journal of Pediatric Ophthalmology and Strabismus , Vol. 41:271-288. D.R.Anderson. (1981). The development of the trabecular meshwork and its abnormality in primary infantile glaucoma. Trans Am Ophthalmol Soc, 79:458-85. David J. Seidman MD1, L. B. (3 March 1986). Signs and Symptoms in the Presentation of Primary Infantile Glaucoma. PEDIATRICS , Vol. 77 No. pp. 399-404. Harley, R. D. (1983). Pediatric Ophthalmology. Saunders. John S Crawford, J. D. (1983). The Eye in Childhood. New York: Grune and Stratton. Kanski, J. J. (2003). Clinical Ophthalmology A Systematic Approach. Butterworth Heinemann. Kwitko, M. (1973). Glaucoma in Infants and Children (ed 2). New York: Appleton-Century-Crofts. Mann, I. (1957). Developmental Abnormalities of the Eye. Philadelphia: JB Lippincott. MillerSJ. (1966). Genetic aspects of glaucoma. Trans Ophthalmol Soc U K., 86:425-34. Moller, P. (1977). Goniotomy and congenital glaucoma. Acta Ophthal, pp. 55: 436-442. Morin JD, M. S. (1974). Primary congenital glaucoma: a survey. Can J Ophthal, pp. 9:17-28. Myron Yanoff, J. S. (2009). Ophthalmology. Mosby Elsevier. NEI. (1968-date). Glaucoma. Retrieved February 2011, from National Eye Institue: nei.nih.gov/health/glaucoma/glaucoma_facts.asp Quigley, H. (1977 Sep). The pathogenesis of reversible cupping in congenital glaucoma. Am J Ophthalmol., 84(3):358-70. Richardson KT, S. R. (1966). Optic nerve cupping in congenital glaucoma. Am J. Ophth., 62: 507. Richardson, K. T. (April 1968). Optic Cup symmetry in normal newborn infants. Investigative Ophthalmology, 137-140. Robert N. Shaffer, D. I. (1970). Congenital and Pediatric Glaucomas. USA: The C. V. Mosby Company. Robin AL, Q. H. (1979). An analysis of visual acuity, visual fields, and disk cupping in childhood glaucoma. Am J Ophthal , 88(5):847-58. Scheie, H. (1955). Symposiumon congenital glaucoma: Diagnosis, clinical course and treatment other than goniotomy (ed 2). Trans Am Acad Ophthalmol Otolaryngol 59, pp. 309–321. Shaffer.RN. (1967). New concepts in infantile glaucoma. Canad J. Ophth, 2: 243. SyndackerD. (1964). The normal optic disc. Ophthalmoscopic and photographic studies. Arch Ophthal, 58:958. Vincent P Deluise, D. R. (1983). Primary Infantile Glaucoma (Congenital Glaucoma). 28(1). Worst, J. G. (April 1968). Congenital glaucoma Remarks on the aspect of chamber angle: Ontogenic and pathogenic background and mode action of goniotomy. Investigative Ophthalmology, 7:127-134.

Internal and External Factors Affecting Four Functions of Management Essay

Internal and External Factors Affecting Four Functions of Management - Essay Example However, an organization that does not reflect on these factors is likely to flop since the external and internal factors will have dire consequences on its performance. To begin with, technology is one factor that has significant effects on the performance of an organization. In the current developing and developed world, many organizations are embracing technology to perfect service and product delivery. Some organizations were formed long before technology was enhanced. However, these organizations are benchmarking other organizations that have incepted technology in its operations. For instance, IKEA was formed in 1943, when technology was not enhanced. However, the organization has been able to enhance its technology to continue giving savored services. Apparently, it is considered that organizations that embrace technology continue to give unparalleled services and products to its customers. This is one factor that has enabled IKEA to attract a large market niche for its products. With improvement in technology, the organization has been able to offer high quality products and services. However, the induction of enhanced technology comes with i ts challenges and setbacks. First, the organization has to settle on technologies that will offer quality services. The technology should offer maximum utility to substantiate the investment in the technology. Secondly, technology is a huge investment which needs massive resources. Therefore, the organization has to collect massive resources in ensuring it is improving in its performance. Lastly, technology requires apt decision making. The organization has to make sensitive decisions on acquiring the stated technology. The second factor that affects the four functions of management is globalization. Globalization is a factor that has improved the performance of many businesses across the globe. Organizations that embrace globalization are likely to reflect a better performance than other organizations that are operating in a defined location. Spreading to other geographical regions exposes the organization to vast markets which create a greater demand for products and services. For instance, IKEA has embraced globalization by opening stores in many places of the world. Initially, the organization recorded low profits and revenue due to its location. However, the management decided to increase its market share by opening other stores in other countries. This has proved a positive approach as the business continues to sprout (Caglar, Kesteloo and Kleiner, 2012). Though this is a big investment, it is also a source of large amounts of revenue. For instance, IKEA has opened large stores in Sweden, Croatia, China and Germany. Previously, the organization was specialized in offering services in Europe. However, with the influence of globalization, it started offering services and products in many parts of the world. Apparently, the biggest stores that the organization has initiated are not situated in the same geographical region. The largest stores in the organization’s name are in Stockholm, Shanghai, Shenyang, Tianjin and Berlin. This shows that the organization is recording a positive performance from the diversity of its market niche. The availability of many markets across the globe ensures the

What are the benefits and weakness of using focus groups Essay

What are the benefits and weakness of using focus groups - Essay Example Assuming these to be correct, structured group discussion is a relevant procedure to obtain people’s opinions, feelings and perceptions, although the interactions between group members have to be borne in mind. (Blankenship, Breen, G.E. and Dutka, A., 1999, 61) The information obtained can be about what each person feels and thinks, but it can also be influenced by a phenomenon such as ‘groupthink’, through which people conform to what others believe. In judging the popularity and the effectiveness of focus groups, it is important to assess the advantages of the method as well as its limitations. In adult education, focus groups perhaps offer a more concrete opportunity for participants and researchers to learn from the process (Field, 2000, 330), being a powerful way of engaging with professionals, policy makers and end-users. The benefits of using such an iterative process in which ‘people’s views and understandings are shared, debated, challenged and changed’ (Field 2000, 325) are more important than the potential disadvantages. Morgan (1999, 142) notes that the majority of the published articles about focus groups refers to the use of this method along with other methods, such as individual in-depth interviews or with surveys. In the research process, focus groups can be used at different points: at the preliminary or exploratory stage of a study; a preparation for decisions about the precise objectives and design of the study; for the collection of the main data; in the closing period of a study to interpret findings, or to generate further perspecti ves for research. Use of focus groups can be seen in applied research as a strategy for collecting data, especially when doing qualitative research to tap peoples subjective experiences (Sullivan, 2001, 23) Focus groups do not invade peoples privacy in order to come to