Wet Lab. Cellular Replacement Therapy And Stem Cell Research Essay

Wet Lab. Cellular Replacement Therapy And Stem Cell Research - Essay Example When embryonic mouse stem cells were isolated more than 25 years ago, the significance of the discovery was soon realized. (Keller, 2005) there are many researchers and hold out hope for cellular replacement therapy arising from stem cell research. Specifically, embryonic stem cells, also known as ES - pluripotent cells are of great concern. They exhibit the potential to differentiate into a variety of final tissue types when they reach their ultimate, fully matured state. Embryonic stem cell lines are usually derived from a blastocyst, or in some cases an earlier stage of embryonic development. The 150 cells which at most comprise the blastocyst are able to differentiate into all types of body tissues. (Stem Cell Information, 2009) Most immediately, a pluripotent stem cell will give rise to the primary germ layers: ectoderm, mesoderm, and endoderm. From these layers, other cells and tissues differentiate but ultimately give rise to all internal organs of the future organism. (Schole r, 2007) Other types of stem cells, further in development also have uses in research and therapy; multipotent stem cells have some flexibility, but usually only within a closely related family of cells, such as cardiac tissue, blood cells. Furthermore, the cells can become Unipotent cells - which are not themselves per se, because they can only produce new cells of the exact same type. On the other end of the spectrum, are totipotent stem cells, these are fertilized zygotes which have the potential to grow into an entire individual, an embryonic stem cell from a blastocyst does not qualify.(Scholer, 2007) Cells can also be classified in terms of progenitor or precursor. Precursors exhibit recognizable traits of the function type they will become, while Progenitors are not outwardly committed to a cell type. (Rabbany et al. 2003) An extensive variety of proteins are responsible for differentiation of which much more research is needed. We are only now discovering the functions of re gulatory operators such as Shp2, or transforming growth factor-?, that aids in the expression of chorionic gonadotropin.(Burnham Institute, 2009), (Keller, 2005) A well-studied pathway is the process of hematopoiesis, by which stem cells give rise to various types of blood cells. (Mackey, 2001) There are essentially two branches to the hematopoietic differentiation process: the lineage beginning with a myeloid progenitor, and the lineage stemming from the common lymphoid progenitor. (Parslow et al. 1997) The lymphoid progenitor arises from the multi-potential Hemocytoblast. The lymphoid progenitor differentiates into what are described as T cells. Differentiation is possible into the natural killer cells, CD4 and CD8 types, known as large granular lymphocytes, from which no further cell lines arise. But the lymphoid progenitor can also become the small lymphocyte. This stem cell has the potential to become a T-lymphocyte helper cell, or a B lymphocyte, which can further differentiat e into plasma cells from which antibodies are produced. (Leishman et al. 2001), (Obeyesekere et al. 2004) But the hemocytoblast from which these types arise produces more cell types along the myeloid lineage. The myeloid progenitor can differentiate into four other cell lines; erythrocytes – otherwise known as oxygen-carrying red blood cells. Immature erythrocytes can be identified by the presence of a nucleus, since they are similar in size and shape to mature erythrocytes – but a nucleus is ejected from the cell upon reaching full differentiation. (Ownby, 2002) Another differentiation event results in mast cells, whose release of histamine and heparin is responsible for many allergic reactions including anaphylaxis. Myeloid progenitors can also

Knowledge Management Techniques Essay Example | Topics and Well Written Essays - 3000 words

Knowledge Management Techniques - Essay Example This research will begin with the definition of knowledge management as the tools, techniques and strategies to retain, analyse, organise, improve and share business expertise. This definition of knowledge management seems incomplete for the reasons mentioned in the following discussion. The definition restricts knowledge management to the business sector only, whereas in my view knowledge management engulfs almost all the real world issues. However the generalization indicated through the terms â€Å"tools†, â€Å"techniques† and â€Å"strategies† makes this sound more appropriate. In practice knowledge management cannot be defined or expressed through specific terminologies. This is because the current meanings associated with the modern tools and gadgets may not be able to cope up with the growing pace of the phenomenon that drives knowledge management. To me the span of knowledge management is ever expanding. The endless limits of data generation and spread o f knowledge owing mainly to globalization are just a few of the factors that contribute to this paradigm of thought. Knowledge management is the effective learning processes associated with exploration, exploitation and sharing of human knowledge (tacit and explicit) that use appropriate technology and cultural environments to enhance an organisation’s intellectual capital performance. The definition explains knowledge management as a combination of processes that are performed on knowledge. These processes are â€Å"exploration†, â€Å"exploitation† and â€Å"sharing†. ... With this description the ever growing meanings of knowledge management cannot be justified. This definition categorically covers the aspects related to technology and cultural environments. The main purpose of the whole exercise indicated in this definition is to improve the organization’s working in terms of intellect. The most useful characteristic narrated in this definition is â€Å"effective learning†. For learning to be effective it needs some scope or domain in which it can be exercised. Generally there is no such thing as ineffective learning. The definition highlights the relevance learning and its respective domain. Definition 3: â€Å"Knowledge – the insights, understandings, and practical know-how that we all possess – is the fundamental resource that allows us to function intelligently. Over time, considerable knowledge is also transformed to other manifestations – such as books, technology, practices, and traditions, - within organis ations of all kinds and in society in general. These transformations result in cumulated expertise and, when used appropriately, increased effectiveness.† (Wiig, 1993) Evaluation: The definition proclaims that the basic entity that works behind intelligence is knowledge. This declaration may refer to the logical exploitation of knowledge as â€Å"intelligence†. Seemingly the words may hold broader sense than expected. The term â€Å"traditions† takes this definition very close to the real life phenomena. The assertion can be seen through the usage of term like â€Å"society†. Books, technology, practices and traditions are considered as varieties of appearances of knowledge. In my view these may also be considered as means or medium of knowledge transfer and usage. Knowledge encompasses both i.e. individual and

Maximizing profits in market structures Essay Example | Topics and Well Written Essays - 1000 words

Maximizing profits in market structures - Essay Example Monopoly – The monopoly is the only producer of a particular good or service; therefore, it has a downward-sloping demand curve. If the firm sells its product at a high price, it will be able to sell only a small quantity because few people would be able to afford it, and there are not substitutes. If the firm would wish to sell more units of the product, it will have to lower its prices (Mankiw, 2009). The type of product may be homogeneous or differentiated and the monopoly firm has full control over its price (Jain & Khanna, 2009). Oligopoly – An oligopoly is a market with only a few suppliers. Because they are so few, actions taken by one seller creates an impact on the other sellers, such that they become interdependent upon each other. They therefore tend to behave pursuant to certain strategies depending on the actions of the other firms (Mankiw, 2009), and there are situations that alternatively present opportunities for conflict and for cooperation. The product may be homogeneous or differentiated (Jain & Khanna, 2009). ... For monopolies, P > MR = MC (price exceeds marginal costs). The firm first determines the output quantity at which it will produce, at the point where marginal revenue and marginal costs are equal. The demand curve is thereafter used to determine the highest price the firm may charge in order to sell the quantity determined. This is so because the demand curve tells the quantity buyers are willing to buy at a certain price. Oligopoly – For oligopolies, the profits a firm makes depends to a great deal of what its competitors make, because there are so few of them supplying the market. Based on this observation, game theory has been developed, the method by which a firm in an oligopoly tries to predict how its competitors will react if it makes a strategic move. For instance, in an oligopoly it is generally observed that firm will lower their price in response to a price reduction by one of the other firms, particularly if the product they produce is homogeneous. However, if one of the firms raises its prices, the other firms do not automatically follow. The reason for this is that the firms whose prices are viewed as too high in comparison with its competitors would lose its buyers to those firms with lower prices, because their products are deemed to be easily substitutable with each other. The result is a kinked demand curve. Barriers to entry Competition - In a competitive market, the barriers to new entrants are low and few, if any, thus the market is open to many sellers and the products are undifferentiated as to be easily substituted. Everybody sells at the same price, and there is always demand at that price. Monopoly - For natural monopolies, barriers to new entrants are high because the

Knowledge Management Techniques Essay Example | Topics and Well Written Essays - 3000 words

Knowledge Management Techniques - Essay Example This research will begin with the definition of knowledge management as the tools, techniques and strategies to retain, analyse, organise, improve and share business expertise. This definition of knowledge management seems incomplete for the reasons mentioned in the following discussion. The definition restricts knowledge management to the business sector only, whereas in my view knowledge management engulfs almost all the real world issues. However the generalization indicated through the terms â€Å"tools†, â€Å"techniques† and â€Å"strategies† makes this sound more appropriate. In practice knowledge management cannot be defined or expressed through specific terminologies. This is because the current meanings associated with the modern tools and gadgets may not be able to cope up with the growing pace of the phenomenon that drives knowledge management. To me the span of knowledge management is ever expanding. The endless limits of data generation and spread o f knowledge owing mainly to globalization are just a few of the factors that contribute to this paradigm of thought. Knowledge management is the effective learning processes associated with exploration, exploitation and sharing of human knowledge (tacit and explicit) that use appropriate technology and cultural environments to enhance an organisation’s intellectual capital performance. The definition explains knowledge management as a combination of processes that are performed on knowledge. These processes are â€Å"exploration†, â€Å"exploitation† and â€Å"sharing†. ... With this description the ever growing meanings of knowledge management cannot be justified. This definition categorically covers the aspects related to technology and cultural environments. The main purpose of the whole exercise indicated in this definition is to improve the organization’s working in terms of intellect. The most useful characteristic narrated in this definition is â€Å"effective learning†. For learning to be effective it needs some scope or domain in which it can be exercised. Generally there is no such thing as ineffective learning. The definition highlights the relevance learning and its respective domain. Definition 3: â€Å"Knowledge – the insights, understandings, and practical know-how that we all possess – is the fundamental resource that allows us to function intelligently. Over time, considerable knowledge is also transformed to other manifestations – such as books, technology, practices, and traditions, - within organis ations of all kinds and in society in general. These transformations result in cumulated expertise and, when used appropriately, increased effectiveness.† (Wiig, 1993) Evaluation: The definition proclaims that the basic entity that works behind intelligence is knowledge. This declaration may refer to the logical exploitation of knowledge as â€Å"intelligence†. Seemingly the words may hold broader sense than expected. The term â€Å"traditions† takes this definition very close to the real life phenomena. The assertion can be seen through the usage of term like â€Å"society†. Books, technology, practices and traditions are considered as varieties of appearances of knowledge. In my view these may also be considered as means or medium of knowledge transfer and usage. Knowledge encompasses both i.e. individual and

Cat in the Rain Interpretation Essay Example for Free

Cat in the Rain Interpretation Essay Topic: The symbol â€Å"cat† in â€Å"Cat in the rain† (Ernest Hemingway) In many of his stories, Ernest Hemingway used symbols to express the profound meaning of those stories. In â€Å"Cat in the rain†, the poor kitty is the main symbol since it expresses much about the theme of the story. In my opinion, the cat symbolizes three things such as a baby, the couple’s relationship and the wife herself. Initially, the cat is symbolic of a baby. The first reason is the cats here stands for something little and vulnerable which is like a baby. Moreover, when it â€Å"was crouched under one of the dripping green tables†, it appears to be so pitiful, which evokes the wife’ caring and protective instinct of a mother. She feels sorry for it because â€Å"It isn’t any fun to be a poor kitty out in the rain†. She calls it â€Å"she† like it is a human. In addition, although the cat is gone, she still wants to have the cat â€Å"sit on my lap and purr when I stroke her†. In short, the wife sympathizes with the cat and wants to treat it lovingly, which is very mother like. Therefore, a baby is the first thing the cat symbolizes. Next, the cat is also a symbol of the couple’s marriage. The little cat silvering in the rain stands for the unstable marriage of the couple. When the wife sees that poor kitty, she immediately goes to save it. She is willing to go through the rain, which signifies the struggles obstructing her. At the end, she cannot have the cat, in other words, cannot save her deteriorating marriage. In contrasts to the wife’s eagerness, her husband seems to be so indifferent since he is reading all the time:†the husband went on reading†, â€Å"George was on the bed, reading†, â€Å"he was reading again†, â€Å"he was reading again†. Although he does propose to go get the cat, it is just a half-hearted offer. It is only the wife who wants to save the relationship, and without the help of her husband, it cannot be saved. In brief, the marriage of the couple is the next thing that the cat is symbolic of. Last but not least, it is the wife herself that is the most important meaning of the cat. When the cat is first described, it is called â€Å"she†, which is intentionally link the cat and the American girl. She is also nameless like a little poor cat lacking attention from other people. The husband says that he will get the cat but later he does nothing, which is like the way he tries to care about his wife but does not satisfy her needs. Therefore, when the wife sees the cat in the rain, she sympathizes with it, she wants it to sit on her lap and stroke it. It is also her inner desire to have someone treat her lovingly like that. In a nutshell, the wife is the last and clearest meaning of the cat in the rain. The story â€Å"Cat in the rain† may seem to be uncomplicated; however, it has much deeper meanings which are partly expressed through the symbol â€Å"cat†. This symbol, which is interpreted to symbolize three things, plays an important role in helping the readers to better understand the theme of the story.

Calorimeter used for calorimetry

Calorimeter used for calorimetry Introduction What is a Calorimeter ? Definition: A calorimeter is a device used for calorimetry, the science of measuring the heat of chemical reactions or physical changes as well as heat capacity. The word calorimeter is derived from the Latin word calor, meaning heat. Differential scanning calorimeters, isothermal micro calorimeters, titration calorimeters and accelerated rate calorimeters are among the most common types. A simple calorimeter just consists of a thermometer attached to a metal container full of water suspended above a combustion chamber. To find the enthalpy change per mole of a substance A in a reaction between two liquids A and B, the liquids are added to a calorimeter and the initial and final (after the reaction has finished) temperatures are noted. Multiplying the temperature change by the mass and specific heat capacities of the liquids gives a value for the energy given off during the reaction (assuming the reaction was exothermic.). Dividing the energy change by how many moles of X were present gives its enthalpy change of reaction. This method is used primarily in academic teaching as it describes the theory of calorimetry. It does not account for the heat loss through the container or the heat capacity of the thermometer and container itself. In addition, the object placed inside the calorimeter show that the objects transferred their heat to the calorimeter and into the liquid, and the heat absorbed by the calorimeter and the liquid is equal to the heat given off by the metals. Functions: As one of the devices used in the science of calorimetry, the calorimeter plays an important role in measuring heat capacity in a number of secure environments, as well as the physical changes that occur with the incidence of specific chemical reactions. This is some information about the general function of the calorimeter and how measuring calories related to the process of identifying heat capacity. Calorimeter is a term that is derived from the Latin word calor, which literally translates to heat. While most people understand the concept of calories as they relate to weight gain or loss, fewer individuals are aware that calorie content is determined by the ability of the substance to generate heat or energy as a result of the consumption. What the calorimeter actually does is identify the rate and scale of the production of that heat or energy and translates into numerical designations that can be used to adequately measure the production and the assimilation of heat and energy. Thus, when thinking in terms of counting calories, what is actually happening is thinking in terms of how much heat and energy will be generated and expended as a result. Calorie measurement has several important applications. One of the most common has to do with health matters. Because the calorie content of some foods is judged to be quite high, the result is that the energy or heat created by the consumption of the foods must make best use of that produced energy. If there is no efficient use of the calories, then the result is energy stored in the form of fat for later consumption. That is why the calorimeter is so important. Proper measuring of calories allows people to more properly plan food intake to ensure that the body has enough heat or energy to function, but does not store excess energy as fat. Types of calorimeter There are a number of different types of the calorimeter that help to measure energy and heat production: 1 :: Adiabatic Calorimeters An Adiabatic calorimeter is a calorimeter used to examine a runaway reaction. Since the calorimeter runs in an adiabatic environment, any heat generated by the material sample under test causes the sample to increase in temperature, thus fuelling the reaction. 2 :: Reaction calorimeters A reaction calorimeter is a calorimeter in which a chemical reaction is initiated within a closed insulated container. Reaction heats are measured and the total heat is obtained by integrating heat flow versus time. There are four main methods for measuring the heat in reaction calorimeter: Heat flow calorimetry Heat balance calorimetry Power Compensation Constant Flux 3:: Bomb calorimeters A bomb calorimeter is a type of constant-volume calorimeter used in measuring the heat of combustion of a particular reaction. Bomb calorimeters have to withstand the large pressure within the calorimeter as the reaction is being measured. 4:: Constant-pressure calorimeter A constant-pressure calorimeter measures the change in enthalpy of a reaction occurring in solution during which the atmospheric pressure remains constant. 5:: Differential scanning calorimeter In a differential scanning calorimeter (DSC), heat flow into a sample—usually contained in a small aluminum capsule or pan—is measured differentially, i.e., by comparing it to the flow into an empty reference pan. 6:: Isothermal titration calorimeter In an isothermal titration calorimeter, the heat of reaction is used to follow a titration experiment. This permits determination of the midpoint (stoichiometry) (N) of a reaction as well as its enthalpy (delta H), entropy (delta S) and of primary concern the binding affinity (Ka). 7:: X-ray micro-calorimeter The detector and X-ray micro-calorimeter, works by sensing the heat pulses generated by X-ray photons when they are absorbed and thermalized. X ray micro-calorimeter diagram. The temperature increase is directly proportional to photon energy. This invention combines high detector efficiency with high energy resolution, mainly achievable because of the low temperature of operation. Micro-calorimeters have a low-heat-capacity mass that absorbs incident X-ray (UV, visible, or near IR) photons, a weak link to a low-temperature heat sink which provides the thermal isolation needed for a temperature rise to occur, and a thermometer to measure change in temperature. 8:: High-energy particle calorimeter In particle physics, a calorimeter is a component of a detector that measures the energy of entering particles. 9:: Heat-loss calorimeter Cross-section view of a heat-loss calorimeter. The heat developed inside the cell is collected by the inner copper cup. Then, it flows through the silicone-rubber which serves as a thermal resistor and the outer copper cup, to the flowing water surrounding the outer copper cup. 10:: Gas calorimeter A gas calorimeter which uses an ultrasonic resonator is in prototype state. It is based on the following mechanism: Periodic temperature changes are produces in the gas-filled resonator cavity by heat absorption, These temperature changes lead to variations of the velocity of sound c via the temperature dependence of c, The change of the velocity of sound results in periodic changes of the tuning of the ultrasonic resonator, The detuning of the resonator is measured by lock-in techniques, The device is simultaneously calibrated an additional heat source at a frequency different from the one to be measured. Gas calorimeter types: Junkers Gas Calorimeter Also known as Gas Calorimeter, Junkers Type Used for determination of calorific values (1000 Kcal/m3 26000 Kcal/m3) of fuel / flue gases at low pressures (2† to 12† W.G) Boys non-recording gas calorimeter The P5615 Boys Gas Calorimeter Set supplied by Cussons has been developed, from apparatus designed by the late Sir Charles Boys F.R.S., to provide a simple but accurate method of ascertaining the calorific values of a wide range of gaseous fuels currently in use. As such it is a necessary item of equipment in any thermodynamics laboratory and is applicable to craft and vocational courses in gas engineering and technology. DESCRIPTION The two main items of equipment in the apparatus are the Boys non-recording gas calorimeter fitted with appropriate burners in the base, and a precision, Hyde type gas meter with a capacity of 2.0 litres/rev consisting of a specially designed measuring drum housed in a gas-tight casing and sealed with water. The whole set is manufactured to a very high standard and is supplied with all necessary accessories including thermometers with reading lenses, measuring vessels and a general purpose set of four burners for town and coke oven gas, natural and methane gas, butane, propane, acetylene, ethylene and propylene. Tru-Therm H Gas Titrator Gas Calorimeter The Tru-Therm Model H real time natural gas calorimeter is a continuous measurement calorimeter instrument that determines calorific Heating Value, Specific Gravity, and WOBBE measurement of natural gas, with continuous rate of update of 10 seconds. Calorific Heating Value is determined by the stoichiometric micro combustion of natural gas. Natural gas and air are supplied to a small instrumentation burner (about 1/2 inch cube) where the flame temperature is directly measured by a thermocouple. The thermocouple provides a signal to the Measurement Engine Control Computer, which in-turn regulates the flow rate of gas to achieve the maximum temperature of combustion. This occurs at the Stoichiometric Point. The gas flow rate that corresponds to this temperature is determined by a precision flow-meter which is sensed by the Measurement Engine Control Computer. Differential Thermoelectric Tritium Gas Calorimeter A device for measuring the amount of any reactive gaseous component in a single gas or in a mixture of two or more gases. The device comprises a reaction chambre, at least one means for supporting a removable catalyst suitable for catalysing the reaction between the reactive component and the gas or gases and at least one heat sensor for detecting and measuring the heat produced or absorbed by the reaction between any reactive component and one or more other gases Exhaust Gas Calorimeters The Exhaust Calorimeter comprise a multi-tube exhaust gas heat exchanger in which the exhaust gases pass through the tubes and the cooling water flows outside the tubes. An exhaust gas sampling point with shut off cock is provided. The cooling water circuit is fitted with a flowmeter on the inlet and a flow control valve on the outlet side. Note that the unit must be arranged for contra flow that is the exhaust gas and cooling water must flow through the heat exchanger in opposite directions. Temperature measuring points are provided for exhaust gas inlet and outlet, and cooling water inlet and outlet. The instrumentation is sufficient to enable the heat content of the exhaust gases to be accurately determined.

Which two metals combined together give the higher voltage when reacting with acid :: GCSE Chemistry Coursework Investigation

Which two metals combined together give the higher voltage when reacting with acid Introduction In this investigation we will find out which two metals combined together give the higher voltage when reacting with acid. The metals used will be:  · Aluminium  · Zinc  · Iron  · Tin  · Lead  · Nickel  · Copper To make a prediction on what metals will be the ones that give the highest voltage when combined together you need to find out if the position in which the metals are at in the reactivity series would make a difference, and if it does, how? You also need to find out how the metals react with acids. We know that the higher the metal is in the reactivity series, the stronger it will react with an acid. Theory Batteries have chemicals inside to store energy. When two different metals that are connected by a wire are placed into an acid, a potential difference (voltage) is produced. This occurs because the metals react with the acid forming Hydrogen acid, a metal salt solution and an electric charge. The charge flows from the most reactive metal to the least reactive metal. Equipment The equipment used will be:  · Acids  · Metals  · Wires  · Voltmeters  · Beakers  · Measuring cylinders  · Stop watches  · Sandpaper Method Collect all the equipment and place it as it is shown on the diagram above. Choose around 10 pairs of metals and place one pair in the beaker, and connect them both with a wire. Put them in for a few seconds, and voltage will be produced when the two metals react with the acid forming hydrogen, a metal salt solution and an electric charge. This charge will flow from the least reactive metal to the most reactive metal. Measure the voltage with the voltmeter and write it down. Do this for every pair of metal you have chosen, and then find out which ones are the most reactive and which ones are the least. Prediction I predict that the highest metal in the reactivity series and the lowest metal in the reactivity series from the metals we are using will produce the highest voltage. I think this because voltage is also called potential difference, so this shows that there is more power when the difference between the metals is larger. This means that the voltage in the metal which is lower in the reactivity series must have a higher voltage to the metal that is most reactive to make my prediction correct. I think that the highest the difference = the higher the voltage. I also predict that changing the acid will change the ending result. I think that the stronger the acid, the higher the voltage.