Poverty in the World Essay Example for Free

Poverty in the World Essay Many third world countries are faced by the challenges of poverty and unproductivity of land. The survival of the people who live in such nations depends mostly on aid from developed countries. There is a fact about the developed countries that needs to be addressed before the aid is delivered to the poverty stricken nations. The developed countries have gained that title due to the fact that they are way too ahead in terms of technology and industrialization. The returns they get from both domestic and foreign trade are redirected on further investment. Incase other nations faced by catastrophes; these returns are used to cover those in need of help. The intervention by these developed nations is a form of quick measures to calming situations down. Back at home, it is funny how the citizens from such nations struggle to make ends meet. Once foreign help is delivered to the nations that are faced by natural, human, or climatic catastrophes the people living in those countries assume that the aid comes from very rich countries. The truth of the matter of foreign aid is that once help is delivered from a certain country be it in form of money or food there are strings attached. If one country demands for help from another, there are possibilities that the national debt of that nation grows. On the other hand, if the help is in form of a donation through the international organizations it is likely that the help addressed the issue at hand and not the future. Going back to the issue of foreign aid and reduction of poverty; two crucial elements come to play. These include the issue being addressed and the type of aid being delivered. Foreign aid is mostly volunteered to suffering nations by developed nations. In other times, organizations and NGOs take responsibility to raise money that can be used to provide for the suffering lot. By assessing the nature of the issue that is being addressed, it can be told whether the form of aid aids in reducing poverty. Looking at the situation at the horn of Africa, the type of help that is being delivered to the starving communities in that region is food and medical supplies. Looking closely at the matter and others similar to that, it will be found out that foreign aid is not a form of borrowed capital but rather a last option. Foreign Aid cannot reduce poverty due to five reasons associated with the problems and the nature of help. First, foreign aid is delivered to rescue and not to prevent; second, it is given when the situation is almost escalating out of proportion; third, nations or parties that require foreign aid are marginalized and the living conditions don’t allow for any form of secondary benefit from the aid; fourth, starvation and disease outbreaks are mostly the problems requiring foreign aid to address the issue quickly; and finally, the nature of aid cannot be invested neither can it be used while other resources are redirected to other activities. The above reasons make foreign aid seem like some form of nutritional therapy’ whose importance is lengthening the period of survival as one witnesses the problems. The US and other nations have been donating relief food and vaccination to African nations and some Asian nations as well for a long time. However, it the aid is form of funds the situation changes from aid to assistance that requires repaying as times advances. Foreign aid d oes not come to the poor in form of basic needs but rather basic rescue. It would be otherwise if foreign aid was in form of compulsory jobs for the poor or mandatory quality education.

Examination and clarification of bioluminescence in marine creatures

Examination and clarification of bioluminescence in marine creatures In order to isolate bioluminescent bacteria from marine samples, one must have a better understanding of the phenomena of bioluminescence. Bioluminescence is a type of luminescence. The light that usually occurs at low temperatures is called luminesence [1]. Chemiluminescence, fluorescence is all the other types of luminescence and should not be confused with bioluminescence. As the result of a given reaction, emission of heat and light takes place, this phenomenon is referred to as chemiluminescence or in other words, chemiluminescence refers to the emission of light in an exergonic reaction. For example, if two reactants namely A and B react, it results in the formation of product, with an excited intermediate C and generation of light. [A] + [B] → [C] → [Products] +  light This is how a chemical reaction takes place [1]. When a substance that has absorbed light or any other radiation of different wavelength in the electromagnetic spectrum, an emission of light takes place by that substance, this is referred to as fluorescence.  In most cases, emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation which has a higher energy [1]. In simple language, bioluminescence is the emission of light from living organisms. One can also describe bioluminescence as chemiluminescence in living organisms. Further clarifications regarding the types of luminescence can be carried out with the help of an experiment that involves the use of glow or light sticks. A solution of luminol in DMSO, sodium hydroxide pellets, an aqueous solution of fluorescent dye and test tubes. Luminol is a versatile chemical that exhibits chemiluminescence, with a striking blue glow, when mixed with an appropriate oxidizing agent [1] [2]. Glow sticks are used to demonstrate the effect of temperature on the rates of chemical reactions. The glow sticks contain two chemicals that are mixed when the glass tube on the inside is broken. This initiates a chemical reaction that gives off light. Higher the reaction temperature, faster is the reaction, and more intense the chemiluminescence. Reaction rates increase about two times for every 10 °C rise in temperature [2]. The luminol experiment demonstrates chemiluminescence and fluorescence. Luminol is oxidized (with molecular oxygen) in the presence of sodium hydroxide pellets. On shaking the test tube (containing luminol and sodium hydroxide pellets), oxygen is introduced into the solution. Hence chemiluminescence stops when the test tube is set aside [2]. When a fluorescent dye is added to the solution, the dye absorbs the light emitted by the luminol and re-emits light at a longer wavelength, changing the color, thus explaining the phenomena of fluorescence [2]. Bioluminescence is the emission of light observed in living organisms. Apart from bioluminescence, there are two other kinds of light emission that may take place from a living organism. These include: (I)Photosynthetic delayed light emission:. It is a weak red light which is emitted by all green plants and algae. This intensity is so low that one cannot see it, though it can be measured [3]. (II)Ultraweak light emission: this occurs in all organisms. It is due to various processes, mostly (but not always) involving molecular oxygen. It is regarded as a by-effect of metabolic activity, but doesnt have a biological function. It cannot be seen [3]. 2. Bioluminescence This is the best known biological luminescence phenomena, mostly because it can be observed using ones eyes only. The bioluminescence occurs among a variety of organisms ranging from bacteria, dinoflagellates, protozoa, sponges, mollusks, echinoderms, insects and fish. The majority of bioluminescent species live in the sea, although there are also many terrestrial bioluminescent insects, especially the beetles. It has been estimated that 60-80% of the fishes in the deep sea are bioluminescent [3]. (i) jellyfish (ii) lightfish (iii) fungi (iv) beetle Fig 2.1: The above pictures show bioluminescence in variety of organisms. The bioluminescent bacteria mainly falls under three genera namely   Photobacterium, Vibrio, and  Photorhabdus. Species within the genus Photobacterium and Vibrio generally exist in marine environment whereas the terrestrial species belong to the genus Photorhabdus. Species within the  Photobacterium  genus are generally light organ symbionts of marine animals, whereas the  Vibrio species exist as free-living forms as well as symbionts in the sea [4].The luminescence of these microorganisms should not be confused with the host organisms. Many fish and molluscs species which have been regarded as bioluminescent organisms have been shown to glow by the light of symbiotic bacteria [3]. The bacteria forms a symbiotic relationship with the host organism as it is provided with a nutrient rich environment for its growth and the host organism has the benefit of camouflage and protection from its predator. Some of the bioluminescent bacteria are obligate symbionts that fulfill their nutritional requirements only from the host, hence they cannot be grown in the laboratory as they cannot be separated from the host organism [4]. Apart from sharing a symbiotic relationship with the host organisms, some of the bioluminescent bacteria are also parasitic in nature, for example, the species in the genus Photobacterium and Vibrio infect the male crustaceans whereas the species in Photorhabdus genus infect terrestrial insects such as caterpillars with nematodes acting as an intermediate host for the bacteria. Majority of the bioluminescent bacteria present on the surface of the marine organisms act as non-specific parasites. The bacterium that resides in the guts of some marine organisms such as crustaceans produces chitinase (an enzyme) that facilitates the decomposition of chitin which is present in their exoskeleton. The different species of bioluminescent bacteria differ from each other in a number of properties including the optimal growing conditions i.e. the nutritional requirements and optimal growth temperature, and the reaction kinetics of the enzyme luciferase involved in light generation. However, the morphology of all bioluminescent bacteria is the same i.e. they are rod-shaped, gram-negative microorganisms with flagella facilitating motion. Bioluminescent bacteria are also capable of growth when the supply of molecular oxygen is limited; therefore they are also examples of facultative anaerobes. Despite the physiological diversity among different species of bioluminescent bacteria, all these microorganisms utilize highly homologous biochemical machineries to produce light. The onset and the energy output of this light-producing molecular machinery are tightly regulated under a central signaling pathway [4]. 2.1 Bioluminescence by squids: Light-emission by most of the marine organisms belongs in the blue and green  light spectrum.This is due to two reasons, firstly because the blue-green light (wavelength around 470 nm) transmits farthest in water, and secondly because most of the organisms are sensitive only to blue light, lacking pigments for the visualization of longer or shorter wavelengths[1]. Squid changes the color of the light emitted i.e. either blue or green light depending on its surrounding temperature. In case of squids, it produces green light when swimming in warm water and blue light in cold water [5]. During the day, the squid resides in the deep waters rather than on surface waters. The sunlight that falls on the deep waters has been filtered with only blue light remaining. The squid matches this color by turning on its blue photophores (photophores are light producing tissues). During the night, the squid is present on the shallow water. The moonlight at shallow depths has not been filtered to a greater extent, as a result both blue and green light remains. The squid matches this color by turning on both of its green and blue photophores [5]. Fig 2.1.1: The picture shows squids bioluminescence [5] 2.2 Advantages of Bioluminescence: There are four main advantages attributed to bioluminescence: Camouflage, attraction, repulsion, and communication. Camouflage Some squids by using the phenomena of bioluminescence defend themselves against predators by producing light (a soft glow) on their ventral surface to match the light coming from above and making their presence indetectable to the potential predators(just as a darker dorsal surface makes aquatic organisms difficult to detect from above. Some can also change the color of their luminescence to match moonlight or sunlight. This is referred to as counterillumination [1]. Attraction Bioluminescence is also used as to attract prey by several deep sea fish, such as the anglerfish. A dangling appendage or a light-emitting rod that extends from the head of the fish that carries the bioluminescent bacteria attracts small animals to the front of its mouth. Fig 2.2.1: Anglerfish lures its prey by using bioluminescence [4]. The cookie cutter shark also uses bioluminescence for luring its prey. A small patch on its underbelly remains dark and tends to appear as a small fish to large predatory fish like tuna. When these fish such as tuna try to consume the small fish, they themselves become prey for the the shark. Dinoflagellates have an interesting twist on this mechanism. When a predator of plankton is sensed through motion in the water, the dinoflagellate luminesces. This in turn attracts even larger predators, which then consume the would-be predator of the dinoflagellate. The attraction of mates in fireflies during the mating season is another proposed mechanism of bioluminescent action. This is done by periodic flashing in their abdomens to attract the potential mates [1]. Repulsion Certain small crustaceans also use bioluminescent chemical mixtures. A cloud of luminescence is emitted, which confuses and then repels a potential predator while the crustacean escapes to safety. This is also shown in some squids [1]. Communication Bioluminescence also plays a direct role in communication between bacteria. It promotes the symbiotic induction of bacteria into host species, and sometimes also plays a role in colony aggregation [1]. 2.3 Biochemistry of the Bioluminescence Reaction As mentioned earlier, bioluminescence is defined as emission of light by living organisms arising from exothermic or exergonic chemical reactions. It is due to the substrate-enzyme complex of luciferin-luciferase within the cytoplasm of the cell. Luciferin refers to any light-emitting compound whereas luciferase is an enzyme. The luciferin-luciferase complex differs among species. In 1887, a scientist named Raphaà «l Dubois isolated light producing chemicals from the piddock, which is a clam that stays in the burrow. He discovered that on placing the clam in cold water, light was seen in the water, that glowed for several minutes, indicating that a light producing chemical was extracted from the clams tissues. He also observed that if he made a hot-water extract from another clam and added this to the original cold-water extract, he could reactivate the light reaction. Dubois called his hot-water extract luciferin and the cold-water extract luciferase. The reaction produces a molecule that is in an electronically excited state. After the molecule gives off energy, it goes back to the ground state and a photon of light is released [2]. Bacterial luciferase is the main enzyme that is used in the phenomena of bioluminescence. Apart from the involvement of luciferase, there are certain other enzymes that supply and regenerate the substrates of luciferase. In bacteria the expression of the genes related to bioluminescence are encoded by an operon called the lux operon.  The lux operon is a 9 kilobase fragment that controls bioluminescence through the catalyzation of the enzyme luciferase. The lux operon has a known gene sequence of luxCDAB(F)E, where lux A and lux B code for the components of luciferase, and the lux CDE codes for a fatty acid reductase complex that makes the fatty acids necessary for the luciferase mechanism. Lux C codes for the enzyme acyl-reductase, lux D codes for acyl-transferase, and lux E makes the proteins needed for the enzyme acyl-protein synthetase. Apart from these genes, there are two more genes namely luxR and luxI that play an important role in the regulation of the operon [1]. Other ge nes including  luxF,  luxG, and  luxH, whose functions are neither clearly defined nor apparently necessary for bioluminescence are also found in some  lux  operons [4]. Fig 2.3.1The arrangement of luxCDABE operon [4] Luciferase is a heterodimer consisting of two different polypeptide chains- alpha and beta (molecular mass 40 kDa and 37 kDa, respectively, and encoded by the  luxA andluxB genes, respectively). The active site is located within the alpha-beta subunit. Absence of beta subunit leads to light emission of a weaker intensity. Studies have shown that the crystal structure of V. harveyi luciferase interacts and forms complex binding patterns between several side chains and backbone amides of the alpha and beta subunits. Studies also reveal that the function of the beta subunit is to act as a supporting scaffold by assisting in the conformational change of the subunit during the catalysis [4]. Fig 2.3.2: Bacterial luciferase structure [4]. Fig 2.3.3: The rectangular box highlights the inter-subunit interactions (ionic attractions, hydrogen bonds, hydrophobic interactions) that play an important role in the assembly of bacterial luciferase enzyme [4]. Bacterial luciferase uses reduced flavin mononucleotide (FMNH2), molecular oxygen, and long chain fatty aldehyde as substrates. During the reaction, the oxidation of FMNH2  and aldehyde concomitant takes place along with the reduction of molecular oxygen and emission of energy, which is released as blue/green light ( MAX~ 490 nm). The energy level of the photon that was produced when the excited electron on the flavin chromophore returns to the ground state is indicated by the characteristic color. Studies have shown that point mutations at the flavin chromophores binding site brings about a change in the color emission spectrum of bacterial bioluminescence, indicating that the distinctive emission color depends not only on the chromophore, but also on the electronic nature of the chromophore-binding microenvironment in luciferase. Aside from bacterial luciferase, some luminescent bacteria also carry fluorescent proteins to; distinguish themselves from other strains by modulating the emission color [4]. For continuous light emission, constant supply of the substrates should be maintained by the enzymes coded by the Lux operon. In addition to bacterial bioluminescence, all the other biological luminescence systems (such as fireflies, coelenterates and dinoflagellates) also utilize molecular oxygen as the oxidizing agent in their luminescence biochemistry, and the processes involved in the reduction of the molecular oxygen serves as an energy sink, draining the reducing power of the substrates. High energy unstable intermediates are formed that dissipate the potential energy of the excited chromophore in the form of light. In this regard, molecular oxygen can be considered to serve as a key to unleash the energy deposited in FMNH2  and fatty aldehyde for bacterial bioluminescence [4].   Fig 2.3.4: The pathway [4] For example, in case of fireflies luciferin reacts with oxygen, with luciferase acting as an enzyme aided by cofactors such as calcium ions, thus emitting light. 2.4 Quorum sensing: The definition of quorum sensing states that it is a type of decision making process used by decentralized groups to coordinate behavior [1]. From the biological aspect, there are many species of bacteria such as Vibrio fischeri, Escherichia coli, Salmonella enterica, Pseudomonas aeroginosa that use quorum sensing to coordinate their gene expression according to the local density of their population. It was first discovered in Vibrio fischeri [1]. Since Vibrio fischeri uses quorum sensing, it constantly produces signaling molecules called as autoinducers. These bacteria have a receptor that recognizes these signaling molecules. When the autoinducers bind to these receptors, it results in the transcription of certain genes, including those for inducer synthesis. There are less chances of the bacterium recognizing its own signaling molecules, hence for the activation of gene transcription, the cell must also encounter signaling molecules from the local environment. Autoinducers and inducers are interchangeably used. If there is less number of same types of bacteria present in the local environment, then the concentration of the inducer decreases to zero thus inactivating the gene transcription. But if the population of the bacteria increases, the concentration of the autoinducers increases, thereby resulting in the activation of gene transcription, thus causing bioluminescence. Therfore, quorum sensing plays a very important rol e in the regulation of luxCDAB(F)E expression in bioluminescent bacteria [1] [4] . Fig 2.4.1: Chemical structure of the autoinducers of bioluminescent bacteria [4] The autoinducer is a metabolic product that diffuses easily across the cellular membrane [4]. Fig 2.4.2: The fig. shows the role played by an autoinducer in the mechanism of quorum sensing [4]. Marine bioluminescent bacteria that is not present as a symbiont (free living bacteria) does not emit light. This is because for the emission of light, accumulation of autoinducers is necessary and this is possible only in a nutrient rich environment which is provided to the symbiotic bacteria [4]. 2.5 Applications of bioluminescence: One of the major applications of bioluminescence is the development of biosensors. A biosensor is a device that detects, records, and transmits information regarding a physiological change or the presence of various chemical or biological materials in the environment. Some bacteria have been designed that gives off a detectable signal when in presence of a pollutant (e.g. toluene) that it likes to consume [6]. In terms of using the phenomena of bioluminescence, efforts are being made to engineer agricultural plants that show luminescence when need watering [1]. As the primary function of bacterial luciferase is to catalyze the emission of light, this feature together with generation of the aldehyde substrate by fatty acid reductase can be successfully produced in other bacteria, by the transfer of the  luxCDABE genes, which convert nonluminescent bacteria into light emitters [4]. Fig 2.5.1: The insertion of the foreign  luxCDABE structural genes into the organism such as E. coli confers the organism the ability to emit light [4]. The ability of the non-luminescent bacteria to emit light by means of recombinant DNA technology has provided researchers an easy alternative to measure and detect the growth and living conditions of bacteria. The phenomena of bacterial bioluminescence are used in the detection of pathogenic bacteria in human food sources. By culturing a food sample in the presence of a recombinant bacteriophage (vector) carrying the  luxCDABE insert, one can readily determine the contamination by bacteria in the food source. In addition, the light emitting property of the  luxCDABE genes has been employed as a reporter of gene expression for studying regulatory controls involved in affecting the efficiency of RNA polymerase in initiation and transcription at different promoters. Then the  luxCDABE genes are under the control of an environmentally regulated promoter (e.g., promoters whose efficiency is highly sensitive to the level of mercury, arsenic, or other pollutants), the structural  lu x genes can function as a biosensor, whose expression will monitor the presence of toxic waste in the environment. In the pharmaceutical industry, genetically modified bacteria carrying the lux genes have been utilized to evaluate the efficiency of antibiotics in fighting against bacterial infections in mammals; with animals such as mice, pigs, and monkeys serving as potential human models. In this screening procedure, the lesser the intensity of luminescence in the infected organs/tissues, the more efficient the antibiotics against bacterial infection; therefore, bacterial bioluminescence serves as an indicator of bacterial growth allowing the proper dosages of antibiotics to be determined and effective treatment to be established [4].   3. Laboratory Experiment 3.1 Sample Collection: After the literature study, it was decided that squid will serve as a sample for this experiment as it is readily available in the U.A.E. fish market. A fresh catch was taken as a sample for this experiment. Since some of these microbes i.e. bioluminescent bacteria are also found in seawater, seawater sample from Sharjah was also collected for this experiment. 3.2 Methodology for the isolation of bioluminescent bacteria from squid: Materials Required: Squid Luminescent Broth (Appendix 1) Luminescent Agar (BOSS Medium) (pH=7.3) (Appendix 2) Procedure: 1. The squid is placed in a beaker and just enough 3.0% NaCl solution is added such that approximately 10-20% of the sample is above the level of the liquid as shown in fig 3.2.1. The NaCl solution preserves the squid by preventing any other microbial growth other than that of bioluminescent bacteria, as required. Fig 3.2.1: Squid placed in a beaker containing NaCl solution. 2. The flask is then kept for incubation in a cool dark room (18-22 °C) and is observed at intervals up to 24 hours. The room is darkened totally such that the flask can be observed for luminous areas on the sample. Sometimes the squid secretes ink that might hinder the view of luminous areas on the squid. In order to prevent this, the NaCl solution is changed when required. 3. Four petriplates of Luminescent Agar (formula above) are streaked from four different luminous areas on the squid. Forceps and craft knife are required and it is used one at a time in the burner for its sterilization. The knife and forceps are then cooled for a while. Squid is held with the forceps and its skin is gently scraped of that shows luminescence with the tip of the knife. The scraped off skin is transferred on to a sterile inoculating loop for streaking on the plates. 4. The plates are then kept for incubation in the cool room (18-22 °C) for 24 hours. (No more than 48 hours.) 5. After observing luminous isolated colonies, these isolated colonies are individually streaked on to a new plate of Luminescent Agar and incubated as above. Fig 3.2.2: Streaked petriplates 6. One or more of the more brilliant colonies is then chosen and streaked onto a slant of Luminescent Agar. The agar slants are incubated overnight or until luminescent growth is seen and then refrigerated. 7. From the agar slants, flasks of Luminescent Broth are inoculated. The flasks are then placed in the shaking incubator for 10-15 hrs at 18-22 °C. [8] The flasks that show bioluminesence is then used for studying the growth curves and characterization of the bioluminescent bacteria. Result and Inference: No luminous colonies were observed from the squid on the first attempt, even though the squid did show luminous areas on its body surface. The failure can be attributed to the fact that streaking was not carried out on the same day it showed luminescence. However, on the second attempt, out of the four petriplates that were streaked with the skin of the squid, only one petriplate showed six luminous colonies. Fig 3.1.3: The above pictures are a reference as to how colonies appear when placed in light (left picture) and dark (right picture) [10]. The colonies that appeared during the course of my experiment (only six in number) were not so densely populated as observed in the pictures above. These six colonies were then streaked on six different petriplates containing Luminescent Agar. The picture below shows bioluminescence in the streaked petriplates. Fig 3.2.4: The picture below shows bioluminescence in the streaked petriplates. The agar slants were also prepared from the petriplates. The six flasks containing Luminescent Broth were then inoculated with culture from the agar slants. The flasks were then kept in the shaking incubator for 18-24 hrs. at room temperature. Out of the six flasks containing Luminescent Broth, only three flasks showed microbial growth. The bacterial cultures were then used for growth curves. 3.3 Methodology for the isolation of bioluminescent bacteria from seawater sample: Materials Required: Seawater sample was collected from Sharjah. Seawater Complete Agar (Appendix 3) Procedure: 1. Seawater sample is collected in a clean container 2. Two plates of SWC agar medium were then prepared. 3. The two plates were then pipetted with 0.1 ml and 0.2 ml of seawater sample respectively. 4. The samples were thoroughly spread over the surfaces of the plates with a L-shaped glass rod. 5. The plates are then inverted after the samples have absorbed into the agar (about 5 minutes) and then kept for incubation at room temperature. 6. The plates were then examined after 18-36 hours. [7] Result and Inference: The plates did not show any luminous growth. This maybe because the sample that was collected was not from deep water as bioluminescent bacteria tends to be present in deep waters. Since no growth was observed, further steps involving the preparation and inoculation of agar slants and luminescent broth could not be carried out. 3.4 Bacterial Growth curve of the isolates: Out of the six flasks that contained Luminescent Broth, only three flasks showed microbial growth. The three flasks that showed microbial growth were then again inoculated into three flasks containing luminescent broth. Their O.D. (optical density) values were measured after every 30 minutes (for 5 hrs) at 530 nm using UV-visible spectrophotometer. The initial O.D. value should be set at 0.05 so that there is sufficient bacterial culture in the broth. The values then helped us in determining the bacterial growth curves. Fig 3.4.1: UV-visible spectrophotometer [11] Procedure: 1. The machine along with the monitor screen is turned on using the switch. 2. The necessary adjustments are then made in the program. 3. For auto zeroing the sample, the blank (broth in which are bacteria is growing) is placed in the cuvette. The cuvette is then placed in the holder. 4. The O.D. values of all the three samples are measured after every 30 minutes for 5 hrs. 5. The optical density vs. time graph is then plotted for all the three samples. Observation Table: Table 3.4.1: Sample 1 Time (in hrs.) O.D. values 0 0.08 0.5 0.09 1 0.12 1.5 0.16 2 0.21 2.5 0.28 3 0.38 3.5 0.5 4 0.71 4.5 0.99 5 1.14 5.5 1.41 Table 3.4.2: Sample 2 Time (in hrs.) O.D. values 0 0.05 0.5 0.06 1 0.08 1.5 0.12 2 0.16 2.5 0.21 3 0.25 3.5 0.38 4 0.44 4.5 0.48 Table 3.4.3: Sample 3 Time (in hrs.) O.D.values 0 0.13 0.5 0.15 1 0.18 1.5 0.23 2 0.3 2.5 0.38 3 0.53 3.5 0.71 4 1.04 4.5 1.16 5 1.37 Result and Inference: Graph 3.4.1: Bacterial growth curve of sample 1 Graph 3.4.2: Bacterial growth curve of sample 2 Graph 3.4.3: Bacterial growth curve of sample 3 The bacterial growth curves of all the three samples suggest that the cultures are still in their exponential phase. The 0.D .values should be measured for a much longer duration so that the stationary and the death phases can also be observed. The broth was kept overnight in the shaking incubator at 18-22 °C. Next morning, only one of the samples showed bioluminescence indicating that the bacterial culture has grown to that level when the lux genes are switched on. Fig 3.4.2: The picture is a reference as to how a flask containing Luminescent Broth shows luminescent growth [6]. The bioluminescence that was observed during my experiment was of low intensity. 3.5 Luminescence (light emission intensity) curve studies on the isolates: For the growth curve studies, agar slants were used to streak on to the petriplates, for the isolation of bioluminescent bacteria. The same set of agar slants were used to revive the culture. The revived culture was then streaked on to the luminescent agar petriplates to study the luminescence curve. However, contamination was observed in the petriplates, even though luminescent colonies were formed. Majority of the colonies that were formed were circular in shape and opaque with a dense material in the centre. Some of the colonies were circular and translucent. These colonies were then again used for sub-culturing. Contamination was again observed in the petriplates. This might be attributed to some error in the methodology of streaking the petriplates. Finally, after five attempts, successful isolation of bioluminescent bacteria took place. These bacteria were then inoculated in the flasks containing luminescent broth. After an over night incubation, these flasks showed bioluminesc ence. These samples were then taken for measuring their light emission studies with the help of an autoanalyser. The luminescence is measured after every one hour. It is measured in terms of counts per second (cps). Meanwhile, the samples are kept in the shaking incubator. Fig 3.5.1: Perkin-Elmer Auto-analyzer [12] Procedure: 1. The machine along with the monitor screen is turned on using the switch. 2. The luminescence mode is then chosen. 3. The wells in the microtitre plate containing the sample are then chosen in the protocol editor. 4. The program is then started. 5. The luminescence of all the three samples is measured after every 1hour. 5. The optical density, luminescence vs. time graph is then plotted for all the three samples. Observation Table: Table 3.5.1: Bacterial Sample 1 Time (hrs.) Cell Density(O.D.) Light emission Intensity (cpu) 0 0.0785 0.5 0.0926 1 0.1189 1.5 0.155 2 0.2139 2.5 0.2826 3

Chicago’s Brownfield Initiative to Reclaim Urban Sprawl and Economic Re

Chicago’s Brownfield Initiative to Reclaim Urban Sprawl and Economic Resources Introduction Brownfields are abandoned, idled or underused industrial and commercial properties where expansion or redevelopment is complicated by real or perceived contamination. In 1993, representatives from the Chicago Departments of Environment, Planning and Development, Buildings, Law, and the Mayor Office came together to develop a strategy for promoting cleanup and redevelopment of the City’s brownfields. The city developed a three- pronged initiative based on this strategy. This paper will focus on Chicago’s efforts to reclaim urban sprawl and return the city’s abandoned or underused properties to productive use. Background information will be provided as well as the issues that concerned the development and an analysis of the procedures, the policies utilized and the outcome. Background Two miles west of the Loop, many of Chicago's communities have devolved into crumbled cement and poverty. Major streets are both populated with teenagers, clusters of children moving with care, fast food joints and liquor stores and abandoned buildings. There is virtually no economic development in these communities. Tucked between these grid points of workaday urban blight are the vestiges of a once vibrant west side. However, this vision has been replaced and now stands factories and buildings that have been long neglected by owners or simply abandoned. These properties have come to be known as "brownfields," their smoked glass windows concealing potential environmental disaster. The new caretakers are homeless squatters, who relentlessly tear the buildings to pieces. Ragged demolition crews, pushing stolen shopping carts, are constantly in t... ...wnfield issues. Sources Cited: Bartsch. Charles. "Financing Brownfield Cleanup and Redevelopment:. 22 March 2001. www.nemw.org/brownfin.htm Sustain The Environmental Information Group. Beyond Sprawl-Chicago Area Land Use Guide. 22 March 2001. www.sustainusa.org/landuseguide/3economics.html United States Environmental Protection Agency. Brownfields Showcase Community. Washington, DC. Nov. 1998. www.epa.gov/brownfields/ United States Environmental Protection Agency. Brownfields Supplemental Assistance. Washington, DC. April 2000. www.epa.gov/brownfields/ United States Environmental Protection Agency. Regional Brownfields Assessment Pilot. Washington, DC April 1997. www.epa.gov/brownfields/ Williams, Drew. "Brwonfields: Chicago starts Reclaiming Its Urban Sprawl". 22 March 2001. www.pollutionengineering.com/archives/1996/pol0601.96/06reprot.htm

The Importance of the Role of the Teacher Essay -- Education Teaching

The Importance of the Role of the Teacher The future of the world is in the hands of the children. Whether the future be a positive or negative one depends on the children and the education they receive. The education of a child is so valuable that one needs to consider the importance of the child's education. Also, one needs to consider how to go about nurturing those bright minds so one day they can become independent individuals. As Educators, one needs to be aware of the short-term effects as well as the long-term effects in which education may play on the child's views of the world. In order to be able to provide a good education to a child, it is necessary for there to be a place in which both the educator and student can meet in equal terms. In order for this to occur there has to be a bond between the teacher and student. Without this bond it is impossible for both parties to set goals, work out those goals together and finally accomplish them. A sense of understanding between both the teacher and student is imperative. A point where both parties meet and are aware of the responsibilities each one has to each other. Both the teacher and student need to be aware of each other's roles and how important those roles play in the achievement of the educator and student. For example, the teacher serves as the provider of information, as well as the one that holds the power in a class. "They hold the grades, and usually students perceive them as holding the knowledge, too" (Zawodniak 124). The way teachers use this power defines the perspective of their pedagogy, the teacher's perspective of the art of teaching. The approach the teacher takes and how much knowledge she would like to deliver to the class depends on th... ... free to speak their mind without being intimidated of the teacher. Once students feel free to speak their mind, they will grow mentally, physically and emotionally, eventually becoming an individual who has learned from the teacher to respect and value knowledge. By working together teachers and students will "achieve a pedagogy that is truly student-centered" (Zawodniak 131), a relationship that is open, honest, and has one goal in mind: that education is the future, and our students hold that future. The power of the future is knowledge, respect it and value it. Works Cited: Cheney,Lynne V. "PC: Alive and Entrenched." The Presence of Others. T Second ed. New York: St. Martin,1997. Zawodniak, christian. "I'll Have to Help Some of You More Than I Wan t>To":Teacher Power, student Pedagogy." The presence of Others. Second ded. New York: St. Martin, 1997.

Slavery :: Slavery Essays

Thesis: Slaves managed to be the main beneficiaries of a movement so entirely unintended for them because, in a series of coincidences brought about by certain effects of Northern progress and improvement, the promotion of their interests became profitable to to the concerns of other classes. Counter-argument: some might argue that slaves could not have been the primary beneficiaries of the progress and improvement taking place in the North in 19th century america b/c there were very few slaves in the north; they were primarily concentrated in the south which was little affected by these changes and with slaves being so remote from the situation, how could they have benefited from it? --while the south obviously did not experience the level of transformation that the north and midwestern regions underwent, it did not go untouched by this era of change--it apparently made southerners even more sealed in their determination to "preserve their way of life based on slavery,"as evidenced by their attempt to secede from the Union. Merely the fact that they reacted so strongly to the changes they perceived in the North indicates the force of the effect that progress had on them. --the very fact that there were few slaves in the north and so many in the south only contributed to the progress-fueled growing distinction between the North and South, the former of whom could not understand--likely because there were so few slaves in the North--the "semifeudal economic and social system" to which the South was "hopelessly attached" due to their dependence on slavery (p. 5, Sheriff). Point: Wage laborers necessary to the realization of improvements in the 19th century began to be perceived as a morally inferior permanent underclass--this elicited fears & changes in opinion involving progress--some (i.e. Bethel society) began to think that one man's (the businessman's) profit came at another's (the worker's) expense--brought about increasing desire for moral reform--leading to 2nd Great Awakening--which in turn led to popularity of abolitionist sentiment. Point: Decreasing reliance on slavery as a necessity to the maintenance of a stable economy, coupled with the still-strong Revolutionary ideals of liberty & equality, drew attention to injustices inherent in slavery. --slaves were necessary before because men were trying to produce huge quantities to ship over to England, at first to pay back their joint-stock companies and then to secure their stability in the "New World." but in the 19th century people were settled into their ways of life, and farmers did not feel such urgency to overproduce.

A Clockwork Orange vs. No Country for Old Men

The movies A Clockwork Orange and No Country for Old Men are both very violent and action movies, but they are quite different in the way they are expressed. Both movies tell disturbing stories about men who killed other people but because of different reasons. This gives us a good reason to compare and contrast these two movies.First, let us look at A Clockwork Orange. This movie is all about Alex de Large, a teenager who is the leader of a gang of criminals. Alex and his friends habitually take in drugs, rob, rape, beat up and kill people, without any remorse or regret. They actually enjoy having pleasure at the expense of others. They have no actual purpose in doing these things, just having their own fun.Alex and his gang do their own thing without a care in the world, not thinking about the authorities or the people around them, not even their own families. Alex himself causes the crack in his friendships with those in his gang when he keeps on making fun of Dim and becomes over bearing over them.Dim and the rest of the gang start making plans on their own, without telling their leader Alex. The story takes a turn when Alex’s friends betray him during a failed robbery, after he hit the woman of the house in the head. They actually hit him on the head and left Alex passed out, to be captured later on by the police.Alex enters a new chapter in his life when the woman he hit eventually died. He was then charged with murder and was sentenced to 14 years in prison, and his friends were not captured because they all turned on him. As Alex was being processed into the prison, his self-pride is being broken down little by little when the prison guards and warden talked down on him and put him in his right place.As 2 years go by, you may think that Alex might be making some progress because of his closeness with the prison chaplain, and his growing interest in the Bible. He also told the chaplain of his desire to be â€Å"changed†. But the scenes where we can see Alex’s real fantasies and daydreams show us that that is really not the case. It seems that he is just interested in doing whatever it would take to gain some favors and get out of prison.Alex finally gets his chance when he hears about a new treatment that would make imprisoned criminals change and would help them stay out of prison. He takes his chances and even presents himself to the Minister so that he would be chosen for the treatment. You might think that Alex might have been having his doubts when he almost didn’t sign the contract, but he did anyway.Things become worse for Alex when he actually goes through the treatment; he cannot do the things he used to want to do! Every time he has the urge for violence or sex, Alex would involuntarily retch and feel nauseous. This is because the Ludovico treatment actually conditioned Alex to react as such. The government and the scientists actually think that the treatment is a success, and they eventually re lease Alex.As soon as Alex goes out of prison, it seems like all of the bad things he did in the past finally caught up to him. All of the pain he caused in the lives of other people all went back to him, making him suffer. His â€Å"redemption† comes in an unexpected way, when he jumps out of a window to escape the pain being inflicted upon him by one of his past victims.The movie’s last scene shows Alex in the hospital, and it seems that he’s back to his old self. It seems that Alex might get away with what he wants to do, after all.

Benihana Of Tokyo Essay

1. What is the Benihana concept? The Beninhana of Tokyo, basically a Japanese Steak House has a very unique concept in terms of the idea of watching the food being cooked live on the table in front of eyes. Benihana featured traditional Japanese cuisine experience in the urban U.S metropolis. It was the first introducer of Hibachi Cooking style in USA, celebrating the cooking of food so alive and entertaining. This experience comes with Teppanyaki tables which accommodated eight people and live cooking of food with service being provided by a chef and a waitress. The concept featured a chef dramatically preparing meals while engaging the eaters around him at the Teppanyaki Table which gave a totally new dining experience. The chefs were mostly trained for the showmanship and the Benihana form of cooking from Japan. This gave a feeling of exclusivity as each table had its own chef and waitress resulting in high engagement and participation from customers end. Benihana not only started with an adopted innovative cooking experience (something that did not exist in USA Before) but also featured Japanese historical authenticity in its design layouts and interior dà ©cor, the walls, ceilings, beams, artifacts and lightings were all from Japan to create a Japanese effect in the restaurant. 2. How does Benihana`s cost structure differ from that of a typical sit-down restaurant? The cost structure of Benihana differs a lot from that of a typical-sit down restaurant resulting in lesser costs and higher profit: Rocky borrowed the method of Hibachi Table to counter the problem of availability and cost of labor and by eliminating the need for a conventional Kitchen, the cost of labor was around 10%-12% of sales as compared to industry average of 30%-35%. By reducing the menu to simple three entrees the wastage was reduced and can cut food costs by 30%-35% compared to the industry average of 38%-48%. The cost of beverages as percent of sales was 20% for Benihana as compared to the industry average of 25-30% resulting in higher gross profit. Due to parental management relationships with the staff, the management salaries were around 4% of Benihana as compared to the industry average of around 6% were lower. Though the sites were chosen carefully but the rent was usually lower for benihana around 5% compared to industry average of 9%. Benihana on average advertised more than the industry and deliberately sent advertising messages to position it differently. Benihana spend 10% of its sales on advertising while the industry only spends 2%. Net Profit after income tax was relatively higher than the industry average for benihana.