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Genetic Algorithms is the area of interest of well-known authors and researchers at the present moment. Genetic Algorithms are an optimization technique David Goldberg has written and researched about. Various applications in a variety of domains ranging from Medial Science to Bioinformatics to Engineering and Business related problems are making use of Gas to make searching efficient.
Approximately two million Americans require warfarin to prevent blood clotting, and the determining factors of Warfarin are ambiguous and for that reason research is being done to find out the factors that play a role in determining Warfarin dose. It is already established that genes hold all the characteristics of an individual. Time and effort in huge amounts is being invested in this area of research. Research shows that genes play one-third part in determining a stable dose in warfarin. Effects of VKORC1 and CYPP2C9, the two genes involved in warfarin dosing, have been and are under study by numerous well-known researchers.
A genetic algorithm (GA) is a search technique used in computing to find exact or approximate solutions to optimization and search problems. Genetic algorithms are categorized as global search heuristics. Genetic algorithms are a particular class of evolutionary algorithms (EA) that use techniques inspired by evolutionary biology such as inheritance, mutation, selection, and crossover. Genetic algorithms are implemented in a computer simulation in which a population of abstract representations (called chromosomes or the genotype of the genome) of candidate solutions (called individuals, creatures, or phenotypes) to an optimization problem evolves toward better solutions.
The evolution usually starts from a population of randomly generated individuals and happens in generations. In each generation, the fitness of every individual in the population is evaluated, multiple individuals are stochastically selected from the current population (based on their fitness), and modified (recombined and possibly randomly mutated) to form a new population. The new population is then used in the next iteration of the algorithm. Commonly, the algorithm terminates when either a maximum number of generations has been produced, or a satisfactory fitness level has been reached for the population. If the algorithm has terminated due to a maximum number of generations, a satisfactory solution may or may not have been reached.
A typical genetic algorithm requires:
A genetic representation of the solution domain,
A fitness function to evaluate the solution domain.
A standard representation of the solution is as an array of bits. The fitness function is defined over the genetic representation and measures the quality of the represented solution.
Once we have the genetic representation and the fitness function defined, GA proceeds to initialize a population of solutions randomly, and then improve it through repetitive application of mutation, crossover, and inversion and selection operators.
GAs are excellent for all tasks requiring optimization and are highly effective in any situation where many inputs (variables) interact to produce a large number of possible outputs (solutions).
It can quickly scan a vast solution set. Bad proposals do not affect the end solution negatively as they are simply discarded. The inductive nature of the GA means that it doesn't have to know any rules of the problem - it works by its own internal rules. This is very useful for complex or loosely defined problems.
Warfarin (also known under the brand names Coumadin, Jantoven, Marevan, Lawarin, and Waran) is an anticoagulant. warfarin was found to be effective and relatively safe for preventing thrombosis and embolism (abnormal formation and migration of blood clots) in many disorders. Despite its effectiveness, treatment with warfarin has several shortcomings. Many commonly used medications interact with warfarin, as do some foods, and its activity has to be monitored by frequent blood testing for the international normalized ratio (INR) to ensure an adequate yet safe dose is taken. Warfarin and related 4-hydroxycoumarin-containing molecules decrease blood coagulation by inhibiting vitamin K epoxide reductase, an enzyme that recycles oxidized vitamin K to its reduced form after it has participated in the carboxylation of several blood coagulation proteins, mainly prothrombin and factor VII. For this reason, drugs in this class are also referred to as vitamin K antagonists.
Warfarin is prescribed to people with an increased tendency for thrombosis or as secondary prophylaxis (prevention of further episodes) in those individuals that have already formed a blood clot (thrombus). Warfarin treatment can help prevent formation of future blood clots and help reduce the risk of embolism (migration of a thrombus to a spot where it blocks blood supply to a vital organ). The type of anticoagulation (clot formation inhibition) for which warfarin is best suited, is that in areas of slowly-running blood, such as in veins and the pooled blood behind artificial and natural valves. Thus, common clinical indications for warfarin use are atrial fibrillation, the presence of artificial heart valves, deep venous thrombosis, and pulmonary embolism (where the embolized clots first form in veins). Warfarin is also used in antiphospholipid syndrome. It has been used occasionally after heart attacks
When initiating warfarin therapy ("warfarinization"), the doctor will decide how strong the anticoagulant therapy needs to be. The target INR level will vary from case to case depending on the clinical indicators, but tends to be 2-3 in most conditions. In particular, target INR may be 2.5-3.5 (or even 3.0-4.5) in patients with one or more mechanical heart valves.
Getting the wrong amount of warfarin can be dangerous - if the dose is too high, patients could bleed profusely, if it's too low, they could develop life-threatening clots.
RELATION OF INR AND PROTHOMBIN TIME (PT)
Medical dictionary describes INR as "International normalized ratio: A system, commonly called the INR, established by the World Health Organization (WHO) and the International Committee on Thrombosis and Hemostasis for reporting the results of blood coagulation (clotting) tests. All results are standardized using the international sensitivity index for the particular thromboplastin reagent and instrument combination utilized to perform the test."
An INR is useful in monitoring the impact of anticoagulant ("blood thinning") medicines, such as Warfarin (Coumadin). Patients with atrial fibrillation often take anticoagulant medications to protect against clots that can cause strokes. While taking Warfarin, patients have regular blood tests to monitor their INR. Just as patients know their blood pressure numbers, they also should know their Warfarin (Coumadin) dosage and their INR.
The prothrombin time (PT) and its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) are measures of the extrinsic pathway of coagulation. They are used to determine the clotting tendency of blood, in the measure of warfarin dosage, liver damage, and vitamin K status. The reference range for prothrombin time is usually around 12-15 seconds; the normal range for the INR is 0.8-1.2.
Prothrombin time (PT) is a blood test that measures the time it takes for the liquid portion (plasma) of your blood to clot.
CLINICAL METHOD OF PTRESCRIPTION
Warfarin, an anti-coagulant, is prescribed to patients suffering from diseases such as pulmonary embolism, atrial fibration and artificial valves
How the Test is Performed?
The health care provider uses a needle to take blood from one of your veins. The blood collects into an airtight container. You may be given a bandage to stop any bleeding. If you are taking a medicine called heparin, you will be watched for signs of bleeding.
The laboratory specialist will add chemicals to the blood sample and see how long it takes for the plasma to clot.
Why the Test is Performed?
Your doctor may order this test if you have signs of a blood clotting disorder.
When you bleed, the body launches a series of activities that help the blood clot. This is called the coagulation cascade. The PT test looks at special proteins (called coagulation factors) that are involved in this event, and measures their ability to help blood clot.
Factor I (fibrinogen)
Factor II (prothrombin)
The normal range is 11 to 13.5 seconds. The PT result will be longer in persons who take blood thinners.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean?
When any of the blood clotting factors are lacking or not working properly, the PT is prolonged.
Increased PT may be due to:
Bile duct obstruction
Disseminated intravascular coagulation
Vitamin K deficiency
Coumadin (warfarin) therapy
Factor VII deficiency
Factor X deficiency
Factor II (prothrombin) deficiency
Factor V deficiency
Factor I (fibrinogen) deficiency
This test is often done on people who may have bleeding problems. The risks of bleeding and hematoma in these patients are slightly greater than for people without bleeding problems. In general, risks of any blood test may include:
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Multiple punctures to locate veins
Stated below is the formula used to calculate INR using PT:
INR = (PT patient / PT normal )ISI
. PT patient is the patient's PT result expressed in seconds.
. PT normal is the laboratory's geometric mean value for normal patients expressed in seconds.