Critical Review of Nokia Essay Example | Topics and Well Written Essays - 1250 words

Critical Review of Nokia - Essay Example From this paper it is clear that decreasing the dependency ratios of the elderly people within the rural municipalities, the project also aims to facilitate in the delivery of better health services and assuring a sustained economic growth. The project, which includes both a literature review on the issue, and an evaluation of the present conditions through discussions, questionnaires, and interviews, will help us to understand the subject matter better by giving us a clear insight into the Finnish health care system, and the use of the technological innovations within this sector. The research question, suitably framed, takes into account the elderly population and the medical services in rural Finland, examines the entire field of medicine and innovative technology. The basic motivation behind this project is the viability of the Health book, is an â€Å"easy to use online medical networking service aimed at senior citizens, communities, hospitals and doctors†. The elderly population living within rural communities will benefit from this online health service by getting direct access to medical and social support without having to go out of their houses. The hypotheses that says ‘quality performing telecommunication connections and broadband accessibility make it possible for people in rural areas to live and work despite long distances’   is measurable both qualitatively and quantitatively. Qualitatively the data can be collected through theoretical studies of books, journals, and articles on the relationship between improved health ca re facilities, and innovative technologies and communications.  

The Physiological Effects of a Concussion on the Brain Research Paper

The Physiological Effects of a Concussion on the Brain - Research Paper Example On the basis of severity traumatic brain injury can be divided into mild, moderate and severe. Concussion or mild traumatic brain injuries are used to describe any injury in which the symptoms may or may not last. Neurologically a concussion is defined as an injury in which there is loss of consciousness for less than 30 minutes and post traumatic amnesia which lasts less than 24 hours. Concussions usually have good prognostic value as usually patient leads to full recovery. A concussion can cause pathophysiological changes to the brain in which there are metabolic and ionic processes due to the twisting of axons (Silver et al 3-6). A concussion occurs due to mild trauma to the brain. The cascades of physiological events that occur are an injury which is followed by abrupt neuronal depolarization. The depolarization excites the neurotransmitters and causes their releases which in turn lead to ionic misbalance and disruption in glucose metabolism. Coupling of neurotransmitters that are excitatory like the coupling of glutamate and the receptor of N-methyl-D-aspartate (NMDA) receptor results in additional depolarizing of the neuron with the ejection of potassium ions and inflow of calcium ions. This alteration in the balance of ions results in fluctuations in the physiology of the brain cells which may be acute or subacute. To counter the potassium-calcium misbalance, the pump of sodium and potassium starts to works with an increase need in ATP’s. This causes an increase in the glucose metabolism and ends in an energy crisis. Axonal twisting and stretching has proved to be the core pathology in the occurre nce of a concussion. The metabolic events that occur post traumatically are uncoupling of cerebral blood flow and glucose metabolism which results in energy emergency. Injection of calcium ions leads to impaired oxidative metabolism. Another physiological change affecting the motor functions of the brain is decreased

Gears The Transmitters of Mechanical Power Essay Example for Free

Gears The Transmitters of Mechanical Power Essay A body under net force is under tranlational motion and a body under net torque is under rotational motion; but they both have something in common and that is both have kinetic energy. This energy can be exploited to do some useful work. The mechanical energy of an object can be used to move another object. Some examples can be a rotating shaft of a motor, which can be used to move a vehicle for public transport. But for this to happen the force, the torque, the mehanical energy or the mechanical power needs to be transmitted from one moving or rotating body to another body. How mechanical force or torque or energy or power is transmitted from one body to another body? There are many ways, many mechanisms like pulley, chain, gears etc. So what is a Gear? Gear is a device, a mechanism through which mechanical force, torque, energy or power is transmitted from one object to another. To draw an analogy gear has same role for mechanical energy that electrical wire has for electrical energy. No not just that role of gear is much more than that. Gears act to increase or decrease the velocity from one moving element to another moving element. This way they has analogy with transformers in electrical domain. A gear is a circular object with a large number of teeth on it and two gears physically engage with each other to transmit mechanical power. This is illustrated in the following picture (http://www. osha. gov/SLTC/etools/machineguarding/animations/gears. html). Figure 1: Two gears engaged with each other In the subsequent sections we will briefly talk about different terminology about gears and about different types of gears: In the most coomon configuration a gear is engaged with another gear. However, it can engage with any other device which has compatible teath. One interesting arrangement is a linear object with teath, which is also termed as Rack. If a gear is engaged with a rack then forms what is known a Rack and a Pinion. It should however, be noted that a rack can be seen as a segment of a gear with infinite radius. Now let us talk about two gears of unequal size engages with each other as in figure 1, above. This combination produces â€Å"mechanical advantage† i. e. angular spee and torque of the second gear is different from that of the first gear. Let us explore this important concept about gears. Mchanical advantage The physical interlocking of the teeth in a pair of gears ensures that circumference of these gears move at the same linear speed. As the angualr speed is circumferential speed divided by its radius; the bigger gear moves at smaller angular speed than the smaller gear engaged with it. Let us look at it from the number of teath consideration. Because the teeth of two engaging gears are locked one to one, by the time all the teeth of the smaller gear have passed the point of contact only a fraction of the teath of the bigger gear has done that. In other words he smaller gear rotates faster than the bigger gear. This results in the following formula (Angular Speed A) x (Number of teeth A) = (Angular Speed B) x (Number of teeth B) or, (Angular Speed A)/ (Angular Speed B) = (Number of Teath B) / (Number of Teath B) This ratio is nothing but Gear Ratio. Similarly, one can dertermine torque ratio. The bigger gear experiences larger torque and vice versa. The torque ratio is equal to the ratio of the radii of the two gears and is inverse of the velocity ratio. Larger torque implies smaller velocity and vice versa. This fact is in confirmity with the law of conservation of energy. In this discussion we have ignored the friction, which dissipates the energy. Velocity ratio being a geometrical term remain unaffected by friction, however there is loss in torque ratio due to friction and thus actual torque ratio is always less than inverse of the velocity ratio. Because, gear is not perfectly circular due to presence of teath on the circumference, there is something called ‘pitch radius’, which is some sort of average between the radius at the root of the teath and at the outer of the teath and is used for these calculations for velocity ratio. Torque ratio etc. The pitch radius depends on the point of contact of the two gears. Also this point of contact keeps changing over time. Due to this the velocity ratio and torque ratio is not constant and instead keeps changing over the period of engagement. These ratios (velocity and torque ratios) that we have discussed so far are gross values and changes from point to point on the gear teath. However, the shape of the tooth can be made such that the velocity ratio remains constant with time on short and long term basis. This is done in good quality gears, because fluctuations in the velocity ratio causes undue vibration, put extra stress on the teeth, which can in turn break as the laod and the speed are many times very high. Keeping the velocity ratio constant is also desired from the precision considerations in devices like delicate instruments, eatches, clocks etc. Now let us compare gears with other mechanisms of mechanical power transmission. Gears and other Means of Power Transmission: There are other mechanisms for mechanical power transmission such as chains, belts, pulleys etc. Each of these has its own advantages and limitations. However, none is as diverse as gears. The problem of slippage is often encountered with these devices and the gears have edge over othe mechanisms. Similarly gears have constant velocity ratio, which is not the case with other devices. However, gears are generally more costly, but this higher cost is initial investment only and is paid back many more times due to very high life of gears than other devices. In the subsequent sections we will talk about different types of gears. Spur gear These are the most simple common gear. This is nothing but a disk with teath projecting radially and the leading edges of the teeth are aligned parallel to the axis of rotation. These gears are used for power transmission between parallel shafts. Such a gear is shown in figur 1, above. Helical gear This is a refinement over spur gear. In this gear the leading edge of the teeth is set at an agle to the axis of rotation and not not parallel to the axis of rotation as in case of spur gear. Because the gear is curved, this makes the tooth to be a segment of a helix. Such a tooth engages more gradually than do spur gear teeth. Therefore, this gear runs smoothly and produces much lesser noise than the spur gear. Besides, helical gear can tranmit power between non-parallel shafts as well. A pair of helical gears can be engage in two ways the shafts can be oriented at at either the sum or the difference of the helix angles of the gears. These configurations of the shafts are known as parallel or crossed, respectively. The parallel configuration is the mechanically more sound than the crossed configuration. In this configuration, the helices of a pair of engaging teeth meet at a common tangent, and therefore, the contact between the tooth surfaces will, is a curve, which extends some distance across their face widths. On the other hand, the helices do not meet tangentially in the crossed configuration, and between tooth surfaces only point contact is achieved. Because of this (the small area of contact), crossed helical gears are and can be used with light loads only. Generally, helical gears come in pairs. The helix angle of one is the negative of the helix angle of the other in this pair and this pair is termed as having a right handed helix and a left handed helix of equal angles. When engaged in the parallel mode, these equal and opposite angles add to zero i. e. the angle between shafts is zero or the the shafts are parallel. When engaged in the crossed configuration, the angle between shafts is twice the helix angle of individual gears. However, it should be borne in mind that parallel configuration of gears and paralles shafts are two different things i. e. parallel configuration of axes may not always lead to parallel shafts. The helical gear is shown in figure 2, below (http://en. wikipedia. org/wiki/Image:Helical_Gears. jpg). Figure 2: Helical gears in parallel and crossed configurations Double Helical Gear This gear is known as herringbone gear as well. This was invented to overcome the problem of axial thrust caused by helical gear. Here teath are of V shape. In this, each gear can be visualized as two standard and mirror image, helical gears stacked. This configuration cancels out the thrust because each half of the gear thrusts in the opposite direction. These can be interchanged with spur gears without changing the bearings.

Medicine Manufacturing: Steps Involved and Types

Medicine Manufacturing: Steps Involved and Types Introduction: There are various types of medicines ranging from veterinary to medicines for human usage. Over the course of time, conscientious and diligent research has been put into improving the quality and effectiveness of medicines. There are hundreds of thousands of medicines available today meant for different ailments but this galore of medicines can be divided into three basic categories Tablets Syrups Gel Every medicine available comprises of two main constituents: Active ingredient and Additives/Excipients. The main remedy is the active ingredient. Whereas, the additives are added to inculcate rigidity, to increase the quantity so that the raw materials can be easily processed and to dissolve certain active ingredients. All human medicines that are produced on industrial scale must go through extensive testing and if its deemed fit for human usage it is produced commercially. There are various standards that are set to test the quality of medicines such as: European directorate for the quality of medicine (EDQM) and U.S pharmacopeial convention (USP). Tablet Manufacturing: In order to make the process more intuitive a specific product (Aspirin) will be discussed. 1. Raw materials: Phenol Sodium hydroxide Carbon dioxide Acetic anhydride Hydrogen Corn starch Water 2. Weighing: The corn starch, the active ingredient, and the lubricant are weighed separately in sterile canisters to determine if the ingredients meet pre-determined specifications for the batch size and dosage amount. 3. Mixing: The corn starch is dispensed into cold purified water, then heated and stirred until a translucent paste forms. The corn starch, the active ingredient, and part of the lubricant are next poured into one sterile canister, and the canister is wheeled to a mixing machine called a Glen Mixer. Mixing blends the ingredients as well as expels air from the mixture. The mixture is then mechanically separated into units, which are generally from 7/8 to 1 inches (2.22 to 2.54 centimeters) in size. These units are called slugs. 4. Dry Screening: Next, small batches of slugs are forced through a mesh screen by a hand-held stainless steel spatula. Large batches in sizable manufacturing outlets are filtered through a machine called a Fitzpatrick mill. The remaining lubricant is added to the mixture, which is blended gently in a rotary granulator and sifter. The lubricant keeps the mixture from sticking to the tablet machine during the compression process. 5. Compression: The mixture is compressed into tablets by a punch machine. On single-punch machines, the mixture is fed into one tablet mold known as dye cavity by a feed shoe, as follows: The feed shoe passes over the dye cavity and releases the mixture. The feed shoe then retracts and scrapes all excess mixture away from the dye cavity. A punch of the size of the dye cavity descends into the dye, compressing the mixture into a tablet. The punch then retracts, while a punch below the dye cavity rises into the cavity and ejects the tablet. The feed shoe returns to fill the dye cavity again, it pushes the compressed tablet from the dye platform. 6. Coating: Tablets may be coated to reduce swallow difficulties or target specific part of the body where the coating will dissolve and take effect. Coating is done by adding desired coating solution to the drum along with the tablets. Blowers are used to rapidly dry the coated tablets and prevent sticking. 7. Testing: The compressed tablets are subjected to a tablet hardness and friability test, as well as a tablet disintegration test. 8. Packaging: The tablets are transferred to an automated bottling assembly line where they are dispensed into clear or color-coated polyethylene or polypropylene plastic bottles or glass bottles. The bottles are topped with cotton packing, sealed with a sheer aluminum top, and then sealed with a plastic and rubber child-proof lid. A sheer, round plastic band is then affixed to the circular edge of the lid. It serves as an additional seal to discourage and detect product tampering. Syrup Manufacturing: 1. General manufacturing procedure: Syrups should be carefully prepared in clean equipment to prevent contamination. Three methods may be used to prepare syrups. Solution with heat Agitation without heat Percolation Although the hot method is quickest, it is not applicable to syrups of volatile ingredients. When using heat, temperature must be carefully controlled to avoid decomposing and darkening the syrup. Syrups may be prepared from sugars other than sucrose (glucose, fructose), non-sugar polyols (sorbitol, glycerin, propylene glycol), or other non-nutritive artificial sweeteners (aspartame, saccharin) when a reduction in calories properties is desired, as with the diabetic patient. The non-nutritive sweeteners do not impart the characteristic viscosity of syrups and require the addition of viscosity adjusters, such as methylcellulose. The polyols, though less sweet than sucrose, have the advantage of providing favorable viscosity, reducing cap-locking (which occurs when sucrose crystallizes), and in some cases acting as co-solvents and preservatives. 2. Cough syrup manufacturing process: Traditional cough mixtures are formulated around a syrup at 60-75% concentration which is made from sucrose, malt dextrin, glucose, invert syrup etc. The remainder is made up of thickening agents, stabilizers and active ingredients. Manufacturers of cough mixtures generally produce their own syrups as this offers greater control of product quality. The manufacturing process must achieve several functions: Dissolving of the sugars to form a syrup Hydration of powdered ingredients Blending ingredients of widely different viscosity Suspension or dissolving of active ingredients The end product must be smooth, agglomerate-free and homogeneous. High Shear mixer is used for mixing. Gel manufacturing Process: 1. Raw materials: Aluminium Acetate, Povidone Iodine, Propylene glycolCremophor RH 40, Lutrol F 127, Cetylstearyl alcohol, Cremophor A 6, Liquid paraffin, Parabene(s), Alpha-Bisabolol, Triethanolamine, Kollidon 30, Benzoyl peroxide, Betamethasone valerate etc. 2. Heating: The temperature should be high enough to ensure the intimate mixing of liquid phase and to prevent the premature crystallization and congealing of its components. Ointments preparation involves separate oil and water phases containing the required ingredients, heating each phase to between 60-70Â °C. 3. Mixing: Mechanical mixers, such as a steel jacketed kettle with agitator are commonly used to prepare semisolid preparations in pharmaceutical industry. The use of mechanical shear or a combination of fusion processes and mixing can be used to facilitate the dispersion or dissolution of the ingredients in the base to form a single-phase ointment. Time, temperature, and mechanical energy input are the three major variables in the manufacturing of semisolid preparations. 4. Emulsification: After the mixing process, the mixer is send to the emulsifier where the immiscible layers are forced to form an emulsion. 5. Cooling: Cooling rate can influence the final product quality. Different cooling rates after melting, mixing, and emulsification steps should be investigated as a process variable. The most important aspect of manufacture is to ensure all ingredients are fully dissolved and well mixed before packing and that the formulations contain suitable effective preservatives. Mixing is continued with cooling until the cream/gel is formed. 6. Packaging: After cooling, the gel is packed. In suspension, mixing of the bulk must be continued during packing to ensure even dispersion of the active ingredients at all times.

Experiment is to investigate the rate of reaction between hydrochloric acid and calcium carbonate :: GCSE Chemistry Coursework Investigation

Experiment is to investigate the rate of reaction between hydrochloric acid and calcium carbonate Hydrochloric acid + Calcium Carbonate Þ Calcium Chloride + Water + Carbon Dioxide 2HCl (aq) CaCo3 (s) CaCl2(s) H2O (aq) CO2 (g) There are a number of variables in this experiment and these are listed below as input variables and outcome variables. The input variables are the ones that I can change in order to affect the experiment and the outcome variables are the ones I will measure to see how the input variable has affected it. Input Variables --------------- Amount of calcium carbonate Amount of hydrochloric acid Surface area of calcium carbonate Concentration of hydrochloric acid Temperature of hydrochloric acid Introduction of a catalyst Outcome variables ----------------- Amount of calcium chloride released Amount of water released Amount of carbon dioxide released Change in weight Out of these variables I will use concentration as my input variable and amount of carbon dioxide released as my outcome variable. You can see how I will use and measure these variables in the method section of this investigation. My preliminary results can be found in appendix 1. These show what measurements of the input variables I decided to use and why I decided this. Prediction ========== I predict that as the concentration of the hydrochloric acid decreases the rate of reaction will decrease and therefore the time taken for 75ml of gas to be released will increase. The reason I believe this is that chemical reactions occur when particles of the reacting substances collide. Increasing the number of the particles increases the number of collisions per second and this increases the reaction rate. In the reaction between hydrochloric acid and calcium carbonate you can increase the number of particles in two ways. The first of these is to increase the surface area of the calcium carbonate. Although this does not directly increase the number of particles, it does increase the number of particles that are available for the H+ ions to react with. This is shown in diagram 1 of appendix 2. The second way to increase the concentration in my experiment is to increase the concentration of the hydrochloric acid. By doing this you increase the number of H+ ions available to react with the calcium carbonate and therefore the number of collisions per second between the two increase. If the number of collisions per second increases then the reaction rate will increase. This is demonstrated in diagram 2 of appendix 2. In order to gain perfect results I would have to use the following weights of each component of the formula and introduce nothing else into the equation. All of the weights are in grams CaCO3 + 2HCl Þ CaCl2 + H2O + CO2

Process Essay - How to Write a Good Essay :: Process Essays

Process Essay - How to Write a Good Essay I present the following; boiled down into the form of a list it may be easily understood by all teachers of writing, even those whose first name is for all intents and purposes "Coach." 1. Get a sheet of paper. This law is thought by some to have been superceded by the advent of computer technology. However, it is still an important first step in that it leads to the following: 2. Sit at a desk with the paper on it, scribbling senseless doodles, silly faces, and, if you are so inclined, the name of an object of affection surrounded by hearts, flowers, and, again if you are so inclined, barbed wire. 3. Start feeling guilty for wasting so much time and begin staring off into space waiting for the muse to start blowing you kisses or for inspiration to shoot a lightning bolt through the top of your head. 4. Hum. 5. Begin tearing pieces of the paper off and put them in your mouth. Chew. Swallow if necessary. 6. Now that you are ready to write your first draft, turn on your computer and/or word processor and begin cruising the Internet or wiping dust off of your screen with the aforementioned paper or your thumb, whichever is more convenient. 7. Remember that you've done no research. Go to the shelf and pick up a volume of the World Book Encyclopedia, preferably "P-R." "Q" always has some interesting topics in it. 8. Finally settle--after combing through a few more volumes--on something to do with Wombats. 9. Remember that the instructor actually gave you a list of possible topics from which to choose. 10. Search in vain for the list of possible paper topics your instructor gave you from which to choose. 11. Call up your friend who is also taking the class and beg her for the list. 12. Meet for coffee. Forget about the list. 13. Call her the next day and ask her to just read a few of the topics over the phone to you. 14. Listen in horror as she says: "You did know this paper is due tomorrow, didn't you?" 15. Go to the library. 16. Research by checking out randomly selected books on vaguely related topics. 17. Highlight like mad. 18. Look at the stack of books for a good long while.

Describe two theories which explain the occurrence of schizophrenia

This paper sets out to look at the mental illness of Schizophrenia and will examine two theories on the cause of this disorder and how they relate to genetics and the environment. The two theories we will discuss are, ‘The Dopamine Theory’ and ‘The Genetic Theory’ Schizophrenia is a chronic and disabling brain disorder which is characterized by gross distortion of reality. The name ‘Schizophrenia’ derives from the Greek words skhizein meaning â€Å"to split† and Phrenos (phren) meaning â€Å"mind† (Taylor, 2011). The condition is categorised by either Positive or Negative Symptoms which are unique to each individual. Individuals suffering from positive symptoms of the disorder experience on-going episodes of psychosis affecting their ability to distinguish, what is real or imagined. Positive symptoms can be defined as symptoms of behaviour that are present but should be absent; they include behaviours such as delusions, hallucinations, fragmented thinking and unusual patterns of speech or behaviour. Negative symptoms on the other hand are the absence of normal behaviours which result in symptoms such as flattened emotional response, inability to express pleasure, apathy, poverty of speech and social withdrawal (Norman, 2004: 365). Schizophrenia is a very complex disorder, and despite on-going debates, researchers have failed to identify one single cause of the disorder, however, it would appear that the consensus is that both biological and environmental factors could play an important role in the occurrence of the illness. One of the most well debated theories on the cause of Schizophrenia is the dopamine theory. The dopamine theory postulates that schizophrenia occurs as a result of hyperactivity of the neurotransmitter dopamine in the synapse. There are four main dopamine pathways which have been implicated in the disorder of Schizophrenia and they are; the Nigrostriatal pathway which is involved in motor control, Tuberoinfundibular pathway associated with sensory processes and the Mesolimbic and Mesocortical pathways which are connected to memory, motivation and emotional responses (Stahl, 2002: 10). Research has given much attention specifically to the mesolimbic pathway which is a brain circuit dependent on dopamine. The mesolimbic pathway is often referred to as the ‘reward pathway’ due to its key role in linking certain behaviours to the sensation of pleasure, such as those associated with the use of psychostimulant drugs like amphetamine, MDMA (Ecstasy) and cocaine (Stahl, 2008: 272). The evidence to support the theory that mesolimbic dopamine plays a role in Schizophrenia, follows logically from the treatment of the disorder with antipsychotic drugs such as chlorpromazine and fluphenazine. These drugs work by blocking dopamine D2 postsynaptic receptor sites, which inhibits the binding of dopamine, thus reducing positive symptoms (Seeman, 2011). Furthermore, several studies have suggested that the use of Psychostimulant drugs (such as amphetamines and cocaine), which work by enhancing dopamine neurotransmission, have been shown to induce psychotic symptoms such as hallucinations, delusions and disorganised speech and thinking, all of which demonstrate a marked resemblance to the positive symptoms exhibited in patients with Paranoid Schizophrenia (Laruelle, et al. , 1996; Breier, et al. , 1997; Abi-Dargham, et al. 1998). Although some research has implicated excess dopamine as a possible cause of schizophrenia, there is still much controversy surrounding this theory. It could be argued that the theory is reliable because research demonstrates that alterations in levels of dopamine either exacerbate or reduce symptoms, however, there are limitations with this theory, as blocking of the dopamine D2 receptor sites will only have an impact on the positive symptoms of schizophrenia, and not the negative symptoms such as apathy, speech and working memory, which are associated with the mesocortical pathway (Wayandt, 2006: 130). It has been suggested by Stahl (2008), that the reason for this may be, that unlike the mesolimbic pathway which is hyperactive in dopamine, the mesocortical pathway may already be deficient in dopamine, therefore blocking of the D2 receptors in the mesocortical pathway could further increase negative symptoms. Swerdlow (2010: 359) suggests that an argument against the dopamine hypothesis may be that some patients may be unresponsive to the more traditional neuroleptic drugs such as chlorpromazine which acts upon the D2 receptor sites. However, studies conducted by Brier and Buchanan (1996) on the use of a new atypical anti-psychotic drug called clozapine, claimed to show a 40-60% improvement in symptoms for patients of schizophrenia who did not respond to the traditional neuroleptics (Pincus & Tucker, 2003: 119). Clozapine still plays a role in blocking the D2 receptor site but with less intensity than traditional antipsychotics. However, it is also responsible for blocking a variety of other receptor sites including dopamine D4, 5-HT (serotonin), norepinephrine, acetylcholine, and histamine (Moses, 2012). With this in mind, it could be said that dopamine does not operate in isolation, and may form only part of the etiology in the manifestation of Schizophrenia. What is clear is that the dopamine theory is far from conclusive, which would suggest that much more research is needed to examine the role that other neurotransmitters may play in the disorder. Furthermore, if dopamine does play a primary role in schizophrenia then this leads us to the question, what causes this dysfunction in the dopamine neurotransmitters? Studies to date have identified that several of the genes which are closely linked with Schizophrenia are directly involved in dopaminergic pathways (Howes & Kapur, 2009); this therefore leads us to a further conclusion that genetics and gene mutation may play a key role in the development of schizophrenia. Evidence suggests that there is a strong genetic predisposition to developing the disorder and the more closely someone is related to an individual with Schizophrenia, the higher the chance of them developing the disorder themselves (Nolen-Hesksema, et al. , 2009). Family, Twin and adoption studies demonstrate that there are higher concordance rates between monozygotic (Identical) twins than there is with dizygotic (non-identical) twins. Studies conducted by Gotteman (1991) found that dizygotic twins had a 17% risk factor if their twin sibling had the disorder; however, for monozygotic twins, the rate increased to a more significant 48%. Further studies have revealed that children of schizophrenic parents showed similar concordance rates of 46%, however, children born to schizophrenic mothers but adopted by non-schizophrenic mothers only showed a risk factor of 17% (Kalat, 2009: 451). These findings suggest that Schizophrenia is not entirely genetic, and that environmental factors may also play a role in the development of the disorder. However, in giving strength to the genetic theory, new research in epigenetics has found that, whilst monozygotic twins share the same DNA, there are variations in the levels of methylation detected in a gene called ST6GALNAC1, which has been found in individual schizophrenic twins (Times, 2011). Whilst these changes in segments of DNA offer some explanations for the discordance in monozygotic twin studies in Schizophrenia, it is suggested that these mutations develop as a result of environmental influences (Coghlan, 2011: 16). Moving on, it has become apparent, that both dopamine and genetics play an important role in the predisposition towards schizophrenia. However, evidence appears to suggest that, whilst an individual may have a predisposition, this is not a guarantee that they will develop the disorder. Theorists believe that for those individuals who do have a predisposition towards schizophrenia, environmental factors can greatly influence the development and life course of the condition. One environmental factor which may be linked to the dopamine theory is the associated risk between prenatal exposure to viral infections and adult onset of schizophrenia (Psychiatry, 2011). Research suggests that prenatal environmental insults such as viral induced anaemia in the first and second trimesters, may lead to deficiency in myelination of neurons and dysfunction in the dopaminergic pathways (Brown, 2011). In support of this claim, a study by (Aguilar-Valles, et al. , 2010) used rat models to produce viral induced iron deficiency, and found that the biochemical and behavioural changes which occurred in the rats were characteristic of those found in adult schizophrenia. Moreover, Brown (2011) also suggests that iron deficiency significantly contributes to de novo mutations in DNA, and this may be due to a possible disruption of oxidation in the cells. Consequently, researchers have also identified significant representation of de novo mutations in Schizophrenics (Krebs & Rouleau, 2011). De novo mutations do not occur as a result of hereditary factors, but instead, are alterations which take place around the time of early conception (Reference, 2012). These findings may support the theory that prenatal environmental insults could be responsible for the increased risk in someone developing the disorder. Furthermore, this may also offer some explanation for the manifestation of schizophrenia in individuals who have no family history of the disorder. In conclusion, schizophrenia still remains one of the most perplexing and misunderstood disorders faced by mental health professionals. It is evident that dopamine, genetics and the environment all play a role in schizophrenia, however not one of these factors appears to work in isolation. In short, it would appear that the environment interacts with both biochemical and genetic factors and determines whether or not an individual is likely to develop the disorder.