Use The Method Of Undetermined Coefficients
Use The Method Of Undetermined Coefficients1
Use The Method Of Undetermined Coefficients1. , y(0)=7, y’(0)=3 2. , y(0)=7, y’(0)=3 3. , y(0)=7, y’(0)=3 4. , y(0)=7, y’(0)=3 5. , y(0)=0, y’(0)=1 Genetically Modified Foods ST4 Learning Objectives ST 4.1 What Are GM Foods? ST 4.2 Methods Used to Create GM Plants ST 4.3 GM Foods Controversies ST 4.4 The Future of GM Foods ST 4.1 What are GM Foods? Defining Genetically Modified Foods • Genetically modified foods (GMOs): Derived from genetically modified organisms – Genetically modified organisms: Plants and animals of agricultural importance whose genomes have been altered – Modified via genetic engineering or recombinant DNA technologies Why make GM foods? • Address malnutrition – increase yield of food – More than 200 different GM foods have been created – Example: Golden Rice: A variety of rice that contains the vitamin A precursor â–ª Developed on a humanitarian nonprofit basis â–ª Purpose: To alleviate vitamin A deficiencies in developing world Making GMOs - Definitions • Transgenic organisms – genes are transferred from one organism to another – Done by genetic cloning • Cigenic: Used to describe genes transferred within a species Biotechnology – part of GMOs • Wide range of methods that manipulate organisms or their components to produce a product – Examples: isolating enzymes or producing wine, cheese, or yogurt Where are GM crops? • GM crops are grown in approximately 30 countries – 90 percent are grown in the United States, Brazil, Argentina, Canada, and India • In the US: – 93 percent of soybeans – 88 percent of corn – 70 percent of processed foods in the United States contain GM crop ingredients Who eats GM foods? • First GM food for consumptions – Flav Savr tomato • Production of GM foods shifted toward agriculture – 200 different GM crops are used as food or Livestock feed • AquAdvantage salmon are the only food source approved for consumption by humans Most prevalent GM crops: Herbicide-Resistant • Why have herbicide-resistant GM crops? – Weed infestations destroy 10 percent of crops worldwide – Herbicides that applied before seeding can be so efficient that they kill crop plants – Tillage damage from controlling weeds leads to soil erosion Highest produced GM food • Herbicide-tolerant GM crops are the most widely planted – 70 percent of GM crops are herbicide-tolerant Example: Contain a bacterial gene that confers tolerance to the broad-spectrum herbicide glyphosate (the active ingredient in Roundup) Second most prevalent GM: Insect-Resistant GM Crops • Makes plants resistant to agricultural pests • Insect damage is a serious threat to food production • Farmers use insecticides to combat issue Example: Bt Crops • Insect-resistant GM crops: Bt crops – Bt (Bacillus thuringiensis) is a group of soil- dwelling bacterial strains â–ª Produce Cry proteins, which are toxic to insects – Bt crops are engineered by scientists â–ª cry genes are introduced into plant cells â–ª The GM crop plant now can manufacture its own Bt Cry proteins, which kills the target pest when it eats the plant’s tissue GM crops for direct consumption • Examples are Rice, squash and papaya • Why?
To increase consumption of missing nutrients or vitamins whose absence results in some disease. • Example: Golden Rice – produces vitamin A – Why? 190 million children and 19 million pregnant women are vitamin A deficient – Between 250,,000 children become blind due to vitamin A deficiencies and half will die within 1 year of losing their sight. Vitamin A also is essential for the immune system. – Other methods of introducing vitamin A into the region have not worked Example: Golden Rice 2 • Golden Rice was genetically engineered to synthesize beta- carotene (precursor to vitamin A) • Geranlgeranyl-disphosphate is present in rice but the enzymes to convert it are not. • GM rice introduces the enzymes needed to make beta-carotene Controversy Regarding Golden Rice • Clinical trials show that the beta-carotene in Golden Rice 2 was efficiently converted into vitamin A • Golden Rice 2 is undergoing biosafety testing • Critics of GM foods suggest that Golden Rice will make farmers too dependent one one type of food • There are concerns about long-term health or environmental effects ST 4.2 Methods Used to Create GM Plants How to Create GM Plants • Creating GM plants: Two approaches 1.
Biolistic method 2. Agrobacterium tumefaciens-mediated transformation • Both methods target plant cells growing in vitro – Plant tissue is cultured that is grown in presence of nutrients or hormones – Cultured cells form clumps that will form roots – The rooted plant develops into a normal plant Biolistic Method – Physical method of introducing DNA to cells – Particles of heavy metals (gold) are coated with the DNA that will transform the cells – These are introduced to cells in vitro using a gene gun – Plants with gene are selected for the desired phenotype Agrobacterium-Mediated Technology • Utilizes bacteria Agrobacterium tumefaciens, a soil microbe that infects plant cells and causes tumors • These characteristics are conferred by Ti plasmid • After Agrobacterium infection, the Ti plasmid integrates a segment of DNA (T-DNA) into plant genome How scientists use the Ti Plasmid • Scientists remove T-DNA and replace with cloned DNA of genes desired • Agrobacterium tumefaciens inserts T-DNA portion of plasmid into host cell’s nuclear genome How to ensure gene of interest insert into plants • Use selectable markers – The rates of successful T-DNA integration and expression are low – Only 1 in 1000 cells is successfully transformed – Selectable markers allow scientists to distinguish between transformed and nontransformed products (colonies, plants, tissues, etc.) Negative Selection • Involves a marker gene: An antibiotic-resistant marker – Example: Hygromycin-resistance gene • The marker gene and a promoter are introduced into plant cells along with the gene of interest • Cells are grown in medium containing hygromycin • Only cells that express the resistant gene survive Positive Selection • Positive selection – One example involves the marker gene encoding PMI: Phosphomannose isomerase enzyme – Catalyzes interconversion of mannose 6- phosphate and fructose 6-phosphate – This enzyme is common in animals but not plants – Plant cells that express pmi gene survive – Can be positively selected by growing cells on mannose-containing medium Example: Roundup-Ready Soybeans • Roundup-ready soybeans – GM plant with resistance to the herbicide glyphosate, the main ingredient in Roundup – Glyphosate interferes with EPSPS genes which synthesize some amino acids in plants – EPSPS are not present in humans How to make the GM soybean plasmid – Utilized Agrobacterium strain Ctp4 epsps gene since it is resistant to glyphosate – E35S – cauliflower mosaic virus promoter – CTP4 – directs EPSPS into chloroplasts – Biolistic technique introduced the plasmid – Selected for by spraying plants with glyphosate – Farmers can spray Roundup on crops and kill only weeds, not their crop of soybeans Method of making Round-up Ready Soybeans How Golden Rice 2 was made • Ti plasmid was used to create Golden Rice 2 – Plasmid contained several genes â–ª crtl gene: Carotene desaturase cloned from bacteria â–ª Psy gene: Phytoene synthase cloned from maize â–ª Pmi gene: Phosphomannose isomerase cloned from E. coli – selectable marker â–ª Glu promoter directs transcription in endosperm â–ª Ubi1 promoter allows transcription in all tissue Method of making Golden Rice 2 Gene editing • Make single nucleotide/single gene changes/deletions without introducing foreign DNA • Not considered genetically modified • Using – ZFN – zinc finger nuclease – TALEN – transcription activator-like effector nuclease – CRISPR-Cas • Examples: – Potato with increased storage life – Pigs resistant to viruses – Double-muscled pigs – White button mushroom that does not turn brown – already in stores The Future of GM Foods: Transgenic salmon • Transgenic salmon is likely to receive marketing approval soon • The AquAdvantage salmon grows twice as fast as a non- GM Atlantic salmon, reaching market size in half the time.
Paper For Above instruction
The "Method of Undetermined Coefficients" is a systematic technique used to solve particular types of nonhomogeneous linear differential equations, especially those with constant coefficients. This method involves assuming a specific form for the particular solution based on the nonhomogeneous term and determining the coefficients by substituting into the original differential equation. This paper will explore how to apply the method of undetermined coefficients, with an example illustrating its step-by-step process, including initial conditions such as y(0)=7 and y’(0)=3.
To demonstrate the method, consider a second-order linear differential equation of the form:
\[
y'' + ay' + by = g(t)
\]
where \(a\) and \(b\) are constants, and \(g(t)\) is a function whose form determines the choice of the particular solution. For example, if \(g(t)\) is a polynomial, exponential, sine, or cosine function, the method provides a structured approach to determine the particular solution.
The solution process involves two main parts: solving the homogeneous equation and then finding a particular solution. The homogeneous equation:
\[
y'' + ay' + by = 0
\]
has a general solution based on the roots of the characteristic equation:
\[
r^2 + ar + b = 0
\]
Once the homogeneous solution \(y_h\) is found, the particular solution \(y_p\) is guessed based on the form of \(g(t)\), using the method of undetermined coefficients.
Suppose \(g(t)\) is a polynomial of degree n. If \(g(t)\) is an exponential function, then the particular solution will involve exponential terms. For sine or cosine forms, sinusoidal functions are used.
Taking the example \(g(t) = ke^{mt}\), the particular solution takes the form \(A e^{mt}\), where \(A\) is an undetermined coefficient.
The method proceeds by substituting \(y_p\) into the original differential equation and solving for the undetermined coefficients. Once both the homogeneous and particular solutions are known, the complete solution is:
\[
y(t) = y_h + y_p
\]
The initial conditions \(y(0)=7\) and \(y’(0)=3\) are then used to find the constants in the general solution.
In practical applications, such as in engineering or physics, the method of undetermined coefficients simplifies solving complex differential equations where the form of \(g(t)\) is known and suitable.
In summary, the method of undetermined coefficients is a powerful analytical tool for solving certain classes of differential equations by systematically guessing the particular solution's form and solving for unknown coefficients through substitution and initial conditions.
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