Social Network and Privacy Research Paper Example | Topics and Well Written Essays - 6500 words

Social Network and Privacy - Research Paper Example To realize this aim, five major objectives were set, based on which research questions were developed. The research questions became a guide for the researcher to collect primary and secondary data, with particular emphasis on primary data collection, where a questionnaire was prepared for 50 respondents selected from a university campus. All 50 respondents were users of social networking sites and had strong academic background in journalism and communication, putting them in a position to providing well informed answers to the questions on the respondent. The primary data collection emphasized largely on the attitude of the respondents towards privacy issues whiles using social networking sites. The primary data collection exercise was also committed to knowing the depth of knowledge on privacy issues with social media networks. Through secondary data collection also, the researcher had the opportunity of knowing what the hosts of social networking sites are doing to protect the pr ivacy of users. Salerno, J. et al. (2011). Social Computing, Behavioral-Cultural Modeling and Prediction: 4th International Conference, SBP 2011, College Park, MD, USA, March 29-31, 2011. Proceedings. New York: Springer. 37 Stewart, K. (2013). Social Network: An Extraordinary Guide on Social Networking for Business, Social Networking for Career Success, Social Network Marketing, Diaspora, Digital Age and More. Montgomery: Tru Divine Publishing. 37 Technology has long been with us but there is no denying the fact that the issue became very topical with the coming of the internet. Up to date, the internet is considered as the most transformed innovation in technological advancement (Zittrain , 2013). Quite so, the internet has several components and aspects that affect the lives of people in different way. The concept of social network had long

Juvenile Delinquency in Hidalgo County Research Paper

Juvenile Delinquency in Hidalgo County - Research Paper Example The violent crime rate is lower in the MSA where Hidalgo belongs because it is 319.20 compared to the Texas rate of 408.60 and the country rate of 386.9 (FBI, 2012).   In other words, the total crime rate in Hidalgo County is higher than the state, particularly its property crime rate, although it has a lower violent crime rate than the latter. When discussing gang presence in the Hidalgo, the Texas Fusion Center Intelligence and Counterterrorism Division of the Texas Department of Public Safety (2013) offers only a rough sketch of gang activities in the region where Hidalgo is in Texas Gang Threat Assessment 2012.   This report stressed that there are approximately more than 2,500 gangs in Texas and Hidalgo County is in a region where gang activity is highest.  There are several parts of Texas that have the highest concentration, and Hidalgo is one of them. Hidalgo is in Region 3, based on this assessment.   In Region 3, the most notable gangs are Tango Blast (Corpitos, Vall ucos), Texas Syndicate, and Texas Mexican Mafia (Texas Fusion Center Intelligence, 2013, p. 17).   Tango Blast engages in violence and Mexican cartels, Texas Syndicate commits violent crimes, as well as human and drug trafficking, while Texan Mexican Mafia is involved in organized crime, extortion, and distribution of black tar heroin (Texas Fusion Center Intelligence, 2013, p. 10).  To deal with these gangs, the state and county offices use different initiatives to tap the resources and systems of local, state and federal law enforcement and state and federal prosecutors.   In general, they integrate resources across intelligence, police, investigative, and prosecution agencies/individuals.  Ã‚  

Latin America colonial times Essay Example for Free

Latin America colonial times Essay ?4. How does colonialism engage with notions of spirituality, witchcraft, and/or (ritual) intoxication? You may analyze how the distinctions between orthodox and unorthodox practices were distinguished (and oftentimes blurred). You may look at Staden, the readings on witchcraft and â€Å"superstition,† etc. Beginning in 1492 when the Spanish under the crown of Castile invaded the Americas, where their first settlement was in Santo Domingo, their main motivations were trade and the spread of the Catholic faith through indigenous conversions and economic gain. Due to these objectives they intervened and attempted to change every facet of the indigenous way of life including their ‘notions of spirituality, witchcraft, and intoxication’. The indigenous population had formally been removed from the jurisdiction of the inquisition by order of King Phillip the second in 1571, however the native people of Mexico and other invaded lands of the Americas were still prosecuted on accounts of witchcraft or being Nauatil (witches). Colonialism engaged with notions of spirituality and witchcraft by asserting their dominance in attempts to completely annihilate these practices. They attempted to make sense of what they did not understand by attributing these happenings to witchcraft and condemning those prosecuted as witches. Further, as previously mentioned, they attempted to spread the Catholic religion by deeming the religious practices previously ‘inherited’ (treatise on Heathen superstition) by the indigenous population as acts of witchcraft. In his letter to Reverend Don Francisco Manso de Zunga, Hernando Ruiz de Alarcon a Spanish navigator of the sixteenth centaury wrote that the reasons behind attempting to completely eradicate the superstitious ways of the people he regarded as Indians was that some of their practices such as â€Å"drunkenness was not permitted to them even in their heathen state† and was punishable by death. (39) His reasons behind â€Å"scraping of drunkenness from the memory of humanity† (39) is that even to those who are believed to be Pagans or non believers (heathens) (39) it was prohibited, therefore once baptised and accepted as Christians it is was a sin to indulge in these acts. To increase the spread and conversion to Catholicism within the Indians, Alarcon, validates the eradication of their customs. Further in his letter Hernando Ruiz de Alarcon explains how by indulging in these superstition practices the Indians are harming themselves. He states â€Å"This (their drunkenness) is the cause of the total destruction of the health of their bodies, and consequently the sufficient and principal barrier to their preservation and increase† (39). Alarcon explains that the deepness with which these practices have fastened into the native American culture leads him to believe that â€Å"the ministers have entered late into their parishioners’ language. † (40). Here we get an indication that despite their conversion to Christianity, Alarcon believes there is no hope to change the Indians’ superstitious ways. In light of the Spaniards determination to spread the Christian faith they attempted to eradicate all other religious practices within the Americas. In his letter Alarcon states in his letter â€Å"others (superstitions) have a weak foundation, because a traditions of their false gods is hardly found among their stories† (39). He explains their previous religion had no concrete roots, they worshiped ‘false gods’ and it was illegitimate; therefore, all rituals and practices for this cause were superstitious. It is important for us to note that the work of finding and documenting the acts of superstition in Mexico was bestowed on Alarcon and therefore it was in his best interest to exaggerate the evidence he supposedly finds. Further, he admits that he is not fully capable to undertake this task because of his â€Å"defective intellect and small experience with writing† (40). In his Treatise on the Heathen Superstition Alarcon explores many aspects of the Mexican native population’s way of idolizing their god’s or goddesses, he attributes this act to an act of worshiping the devil. This is another example of how the Spanish used the notion of witchcraft to propel the spread of Christianity. In his treatise Alarcon states â€Å"and by this means they usually communicate with the devil, because he usually communicates with them when they are deprived of judgement with the said drink and deceives them with different appearances† (48). In this example we can see how Alarcon uses Christianity and the threat of the devil to abolish drunkenness. Alarcon also uses the Devil to explain phenomenons that were beyond the scope of the Spanish understanding. He states in his treatise, â€Å"they (the sages in Mexico) are always deceitful and ceremoniatic and seek to persuade people that they are consummate in knowledge, since they profess to know what is absent and to foresee what is in the future, which, it may be, is revealed to them by the Devil, who can, through knowledge and conjecture, foresee many future events. † (45). Due to the fact that Alarcon and other Spaniards at that time could not make sense of why the prophecies or futuristic readings of the native Mexican sages were holding true, they declared it an act of the Devil and therefore a form of witchcraft. Another example of the Spaniards condemning the unexplainable acts in the Americas is in the document â€Å"On her Deathbed, Maria de la Candelaria Accuses Michaela de Molina of Casting Spells† produced in Guatemala in 1696. In this text different testimonies of various people that witnessed the sickness of Maria de la Candelaria a girl servant. In the testimony of Dona Juana Gonzalez a Spanish woman and mistress of Maria, she states, â€Å"the reason that she presumes this (that Michaela de Molina had casted spells on Maria) is because her servant, Maria had some fights with [Michaela] and not with anyone else. † (170) The Spaniards and even the natives of Guatemala could not fathom why or how Maria was dispelling such large amounts of blood and various objects like stones, rags and hair from her mouth and nose therefore attempted to reason it by condemning Michaela in the act of witchcraft. It is important to understand why the Spanish were interested in Maria’s sickness. In Spain and other parts of Europe the acts of witchcraft were highly condemned. People were afraid of loosing their power and therefore they feared the unknown. They condemned it by illegalizing all forms of witchcraft. Further, the act of ‘drunkenness’ and other practices not coherent with the beliefs of Christianity were also attributed to witchcraft therefore abolishing witchcraft became a means to spread the Christian faith specially since the indigenous population had formally been removed from the jurisdiction of the inquisition by order of King Phillip the second in 1571.

Media And Growth Of Bacteria

Media And Growth Of Bacteria To grow and reproduce, microorganisms require nutrients as their source of energy and certain environmental conditions. Adaptation to different habitats has been acquired by microbes living in the exposed environment. In the laboratory, however, these requirements are to be met by a culture medium. Therefore, media preparation is an essential aspect in microbial growth. There is a wide variety of media which can be used for laboratory purposes. Generally, similar procedures can be used in the preparation of media. In this practical, YT broth is prepared from yeast extract, trypton, NaCl and agar. YT broth is a commonly used bacterial Esherichia coli culture media in molecular biology. Usually, YT medium is applicable for phage DNA production. Compared to LB broth, YT is a richer medium in which it supports higher cell density and a longer growth period for E. coli. Bacteria are the most abundant and most important biological component as they involve in the transformation and mineralization of organic matter in the biosphere (Cho Adam, 1988; Pomeroy Wiebe, 2001). Generally, growth is defined as an increase in number of cells. Bacterial cell growth depends upon a large number of cellular reactions such as transforming energy. Syntheses of small molecules are performed to build macromolecules and to provide various cofactors and coenzymes for biochemical reactions. Polymerization of monomers builds the macromolecules in the bacterial cell. As the macromolecules accumulate in the cell, they are assembled into new structures with specific functions such as the cell wall, cytoplasmic membranes, ribosomes and flagella, if to name a few, and eventually lead to cell division. E. coli is used as a test organism in this practical for investigating the bacterial growth. Such a growing rod shaped cell bacterium elongates to approximately twice their original length and then forms a partition that constricts the cell into two daughter cells. This process is known as binary fission. A partition called the septum is formed by the inward growth of the cytoplasmic membrane and the cell wall from opposite directions. The septum continues to grow inwards until the two daughter cells are pinched off. When one cell separates from to form two daughter cells, one generation has occurred and the time required for binary fission is known as the generation time. Under the best nutritional conditions, the generation time of a laboratory E. coli culture is approximately 20 minutes (Buettner et al., 1973). The growth stages of bacterial cells are described in a growth curve consisting of the lag phase, exponential phase, stationary phase and death phase (Zwietering et al., 1990). In the lag phase, the bacterial cell begins to grow only after a period of time due to new environment being inoculated. The time interval of lag phase depends on the growth conditions and the history of the inoculum. If the growing culture is transferred into the same medium under the same conditions, there is no lag phase and exponential phase starts immediately. However, if the inoculum transferred is taken from the stationary phase in an old culture, lag phase is observed. This is because certain essentials of the cell have depleted and time is required for biosynthesis of new constituents. The lag phase is also observed when the cells are transferred from a rich culture medium to a poorer culture medium. In the poorer condition, the cells need to synthesize the essential metabolites that are not present i n the previous medium. Thus, time is needed by the cells to produce new enzymes. In the exponential phase, the cell divides to form two cells, both the total cell number and mass double but there is no change in the average cell mass. The cells are said to be in their healthiest state. The rate of exponential growth varies widely among microorganisms. The rate is influenced by environmental conditions and the genetic characteristics of the organism itself. In the stationary phase, the essential nutrients of the culture medium are used up and at the same time, the wastes produced by the bacterial cells accumulate in the culture medium. Thus, growth is inhibited. The exponential growth is ceased and the cells reach the stationary phase. There is no net increase or decrease in the cell number and hence the growth rate of the cells is zero. The cells enter the death phase of the growth cycle after reaching the stationary phase whereby cell lysis occurs. Figure 1: Typical growth curve of a bacterial population. The growth of E.coli is investigated under various cultural conditions, including effect of pH, temperature and aeration). Effect of pH is ascertained by preparing media of different pH values. Temperature is always a potentially limiting factor by affecting all chemical and biochemical processes and thus is viewed as an interactive factor (Pomeroy Wiebe, 2001). Aeration is done by shaking so that air space volume can be increased. As such, good and excellent aeration is stimulated. MATERIALS Media components (yeast extract, trypton, NaCl and agar), E. coli culture, 20x petri dish, 5250 ml conical flask and 1100 ml conical flask, plus cotton wool plugs in aluminium foil, Whatman paper METHOD Media Preparation The five 250 ml conical flasks and one 100 ml conical flasks were prepared and labelled as M1-M10 on the first day of practical. 100 ml of YT broth was prepared in 250 ml flasks, with the composition as trypton 1.6%(w:v), yeast extract 1%(w:v), and NaCl 0.5%(w:v). The pH was adjusted to those shown in table 2.1, followed by autoclaving. 500 ml agar was prepared in 1L flask, in which composed of YT broth and agar (13.5 g/L). The prepared medium was autoclaved. The agar was poured on 20 petri dishes. Inoculation Day 2 was begun with inoculating M1 to M8 with 1.0ml E. coli, while M9 and M10 as control set. Incubation was performed at 37Â °C for 24 hours. Whatman paper was dried overnight. Analysis Prior to an analysis, the culture was well shaken and the sampling was done under aseptic condition. Measurement of cell density and variable cell (as colony forming units, cfu) After the overnight incubation, a 3.0ml aliquot of each culture was taken and the absorbance was measured at 660nm. M9 and M10 was used as the blank. Data obtained was tabulated. Measurement of final pH of broth The final pH of the cell culture was measured. The results were also recorded in table 2.1. Measurement of CFU At day 3, a serial dilution was done from 10-2, 10-4, 10-6, 10-8 to 10-10. Hockey stick spreading technique was performed to plate out the sample. Two replicates were done for each plate, labelled a and b respectively. The culture was incubated at 37Â °C for 24 hours. The changes were observed and recorded on the next day, and thereby determining the CFU, as what recorded in table 2.2(a) and 2.2(b). Measurement of biomass The Whatman paper dried was weighed and the initial weight was recorded. A 10ml aliquot of the content of the flasks was filtered using the Whatman paper by washing with distilled water. The paper together with the content was dried in oven at 70Â °C overnight. On the next day, the final weight was measured and thereby obtaining the net weight gain of the filter paper. The result was recorded in table 2.3. RESULTS The pH change and the absorbance values measured were recorded in table 2.1. Flask M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 Pre-incubation pH 4.0 7.0 10.0 7.0 4.0 7.0 10.0 7.0 7.0 7.0 Post-incubation pH 3.96 7.08 10.16 7.16 4.13 7.21 9.93 7.73 7.12 7.14 OD660nm 0.108 1.267 0.01 0.916 0.191 1.906 0.056 1.812 0.0 0.0 Growth condition No shaking (with air space) No shaking (without air space) Shaking at 200 rpm (with air space) Shaking at 200 rpm (without air space) Table 2.1: pH change and absorbance measured for M1 to M10 CFU for plate labelled a and for plate b was calculated using the formula below, which was then recorded in table 2.2(a) and 2.2(b) respectively. CFU = colony number x dilution factor = x cfu/0.1ml = ? cfu/ml Table 2.2(a): CFU for plate labelled a Flask M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 Dilution (10-4) 55 22 0 >300 1 161 0 >300 0 0 CFU/ml 5500000 2200000 0 TMTC 100000 16100000 0 TMTC 0 0 Dilution (10-6) 0 13 0 185 0 24 0 3 0 0 CFU/ml 0 130000000 0 1850000000 0 240000000 0 30000000 0 0 Flask M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 Dilution (10-4) 13 >300 0 >300 0 >300 0 >300 0 0 CFU/ml 1300000 TMTC 0 TMTC 0 TMTC 0 TMTC 0 0 Dilution (10-6) 0 3 0 89 0 32 0 4 0 0 CFU/ml 0 30000000 0 890000000 0 320000000 0 40000000 0 0 Table 2.2(b): CFU for plate labelled b The biomass was calculated using the formula below and was recorded in table 2.3. Biomass (g/ml) = Flask M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 Initial weight of filter paper 1.14 1.16 1.14 1.17 1.19 1.15 1.16 1.19 1.16 1.17 Dried weight of filter paper 1.15 1.17 1.14 1.17 1.20 1.17 1.16 1.19 1.16 1.17 Mass Difference 0.01 0.01 0.0 0.0 0.01 0.02 0.0 0.0 0.0 0.0 Biomass (mg /ml) 0.001 0.001 0.0 0.0 0.001 0.002 0.0 0.0 0.0 0.0 Table 2.3: Biomass DISCUSSION From the tables in the result section and observation, we analyze the growth of E. coli under various pH and aeration condition. Measuring OD and calculating CFU give relevant and supportive information to our experiment. However, the biomass calculated is not applicable to accurately ascertain the factors affecting the growth as some errors occurred during the measurement of biomass, probably. Cell density and variable cell OD stands for optical density which indicates the wavelength of light. In this practical, OD660 measures the light absorbance by E. coli cultures, which correspond to the E. coli cell density in a given volume. OD660 determines whether the cells are ready for making cell stocks or as a competent cell. In other words, it can be said that in this part, OD660 was used to ascertain the quantity of E. coli grown in the YT broth after incubating overnight at 37Â °C. Flasks M1 to M8 were inoculated with 1.0 ml of E. coli culture. The result showed that growth had occurred. On the other hand, M9 and M10 served as the control set in which inoculation of bacteria was not applied, in addition to acting as blank during analysis with spectrophotometer. From table 2.1, it was shown that the OD of both M9 and M10 appeared to be zero. This shows that there was no sign of growth of E. coli in the two flasks. Spreading of plates was done in class II laminar flow cabinet. Sterile operation in cell culture is vital where it can affect the CFU of E. coli. This minimizes the chance of culture contamination. On top of that, the safety of the operator is ensured (Betler, 2004). From the aspect of CFU, as what shown in table 2.2(a) and 2.2(b), there was abundant of cells in M2, M4, M6 and M8. The cell density was still high even with the dilution of 10-6. Therefore, it was determined that E. coli has the optimum growth pH at 7.0. Effect of broths pH on growth Different growth condition gives different OD values. Optimum pH of E.coli growing in a culture at 37oC is around 7.0. E.coli is not able to tolerate under extremely alkaline and acidic environments because most of the enzymes found in the bacterium are very pH-sensitive. These enzymes carry out the important processes in E.coli. When there is extreme change in pH, enzymes in E.coli become denatured. Denature of enzymes in E.coli can lead to all sorts of interruptions to biochemical processes or even causes death of the E.coli. From table 2.1, it was found that there was no growth of E.coli in both flask M3 and M7 with pH 10.0; as the absorbance measured were 0.01 and 0.056 respectively. Whereas, there were some E.coli grow in flask M1 and M5 with pH 4.0, which have OD recorded 0.108 and 0.191 respectively. Thus, it can be concluded that E.coli seems to be more tolerate to lower pH (acidic condition) than higher pH (alkaline condition). Since pH 7.0 is the optimum pH for the growth of E.coli at 37oC, there were many colony of E.coli growing on the agar plates which spread with the sample from flask M2, M4, M6 and M8. There are some changes in the pH before and after the incubation. This is because there is formation of inhibitory products such as organic acids during the growth of E.coli in the YT nutrient broth. Effect of aeration on growth pH of medium is determined by medium composition, buffers, cellular metabolism and aeration. NaCl is used as buffer, where the depletion of this organic buffer will cause an E. coli reaches its maximum pH limit. Hence, care has to be taken to balance the organic buffer, sugar content and aeration medium because low aeration leads to production of acids; High aeration causes cells to use organic acids as carbon source, and thus increases the pH of medium. In brief, selected aeration also helps in maintaining cells pH. Theoretically, shake flask incubator reduces the solid and liquid inter-phase, thus minimizing the mass transfer. Increased speed and momentum cause cells to lyse among themselves. Increased speed also increases the formation of foam, thus trapping gas and resulting less gas in the liquid. Since cells require nutrients for survival, absence of gas as nutrient source will cause cells to die. Hence, shaking flask actually plays an important role in bringing an improvement to mass transfer between the gas phase outside the shake flask and the liquid phase inside the shake flask. Shake flask incubator can provide a suitable environment by ensuring sufficient transfer of oxygen gas to the cell culture by appropriate mixing. Agitation will increase the aeration of the bacterial growth of E.coli. This is because oxygen is important for high density growth of E.coli cells. Agitation is controlled by the shaking speed of a shaker incubator. Thus, from the observation, Whatman paper with content from M6 has bigger biomass than others. The biomass of M6 is 1.0 mg/ml. This is because flask M6 has been shaken at 200rpm and the flask contains air space which helps in the growth of E.coli cells. Therefore, the media without shaking or without air space or without both of these growth conditions has less growth of E.coli. Thus, M6 has the best growth condition for E.coli if compared with other media. However, from the observation in this experiment, there is more E.coli colony grows in M8 (growth condition with shaking at 200rpm but without air space) than M6 (growth condition with both shaking at 200rpm and with air space) in the culture with serial dilution 10-4. Theoretically, there should be less E.coli colony grows on the plate which spread with the culture from M8 since flask M8 has less flavour growth condition for the growth of E.coli. This unexpected observation may be because the sample with serial dilution 10-4 is not well shaken before take 1.0ml of aliquot to spread on the plate. From our result, it was again determined that the growth rate of E. coli is not affected by shaking. This is proven through our experiment where there was no significant difference in yields with or without shaking cultures. When air is supplied, however, shaking cultures shows a higher yield than static cultures. The main purpose of shaking cultures at 20 rpm is to mix thoroughly the nutrient concentration in broth, with constant temperature, 37Â °C. 37Â °C is the optimum growth temperature for E.coli. Shaking prevents cells localizing at the bottom of the broth which causes a faster depletion of nutrient as time passes. Nutrients still present in the broth but cells may not accessible to them. Hence, shaking minimizes areas of high and low nutrient concentration. The amplitude of the vibration controls the intensity of fluid mixing. Shaking broth brings advantage to non-motile cells because it enables the metabolism rate to continue, in addition to benefiting mobile cells by redu cing energy on mobility. Besides, shaking increases the aeration of broth which leads to a higher yield of E. coli. From the OD values, OD at pH 7 shows the highest value for both shaking and non-shaking media because pH 7 is the most suitable medium for growth of E.coli. However, pH 7 from shaking broth has a comparatively higher OD reading compare to non-shaking broth due to shaking enhances the growth of E.coli. However, OD of pH 4 is far higher than OD of pH 10 because E.coli can still grow on pH 4, but pH 10 does not really support growth of E.coli. As for M9 and M10, both broths do not show any OD reading value because no E.coli culture is added into both broths. When pH and vibration are held constant (i.e. pH 7 with shaking), broth with aeration shows a higher OD value compare to non-aeration. This means that a higher E.coli cell density in aerated broth compare to non-aerated broth. When other factors are held constant, air space does not significantly affect E.coli yields, because E.coli is a facultative anaerobe, which means E.coli is able to produce energy during aerobic respiration and switch to anaerobic respiration when oxygen is depleting in the environment. Thus, E.coli grows in both with or without air space broth. Supposedly, colony forming unit (CFU) in plates from medium with air space has a higher growth amount compare to medium with no air-space. This is because E.coli cells produce a large quantity of acetic acid with no air-space, and thus reducing the pH of broth and does not favour the growth of E.coli. Acetic acid inhibits growth condition under anaerobic growth condition. However, according to our result, when the pH and vibration are held constant (both of pH 7 and with no shaking), CFU is greater in non air space compare to with air space. This may be due to errors occur where the mouth of broth is not tightly covered which leads to entranc e of oxygen molecules into the broth. CONCLUSION Sterile medium such as sterile YT broth is essential for bacteria growth. The optimum pH for the growth of E. coli is 7.0. Excellent aeration promotes growth of bacteria to a further extent than what good aeration does. QUESTIONS Write a flow chart for the above protocol before you start work. Label all the conical flasks from M1 to M10 Add 100ml YT broth to flasks M1 to M3 and M5 to M7 Adjust the pH of the media to 4.0,7.0 and 10.0 using either HCL or NaOH Autoclave and allow to cool to room temperature For flask M4 to M8, autoclave 200ml of the medium in a bigger container and then pour the cooled medium into the sterile 100ml conical flask Inoculate flasks M1 to M8 with 1.0ml of E.coli culture under aseptic conditions Incubate with or without shaking as indicated from the table Prepare M9 and M10 under the same conditions as for flask M2 and M6, but do not add any inoculum Prepare and autoclave the agar After an overnight incubation,take 3.0ml aliquot of each culture and measure the absorbance at 660nm Do a serial dilution from 10-1 to 10-5 in a sterile microfuge tube and plate out 0.1ml of the sample at 10-4 to 10-5 in YT agar media Incubate at 370C overnight Determine the cfu/ml of the original culture and tabulate data Measure the final pH of the cell culture and tabulate results Filter 10ml aliquot of the content of the flasks using pre-weighted Whatman paper dried in an oven at 800C overnight Measure the net weight gain of the filter paper as an indication of biomass Tabulate results Discuss your results with respect to the effect of pH of the media and aeration on bacterial growth and reasons for your observations. In addition to nutrients, the pH of the growth medium is also important for E.coli growth rate and cell density. The optimal growth pH for E.coli is near neutral. E.coli cells can grow reasonably well over a range of three pH units (from pH 5.5 to 8.5). Extreme pH beyond this range will significantly decrease the cell growth rate and may sometimes even cause cell death. The minimum and maximum growth pHs for E.coli are pH 4.4 and 9.0 respectively. E.coli cells appear to tolerate a more neutral pH better than a high pH. This is clearly shown as E.coli grows well at pH 7 as shown on plate M2, M4,M6, and M8.In fact, extended exposure of E.coli cells to a high pH causes cell lysis. This is the reason why no colonies were found on plate M3 and M7. At the saturation or stationary phase, the pH of the E.coli culture in commonly used media is near its pH limits. pH is another limiting factor for cell growth in addition to nutrition exhaustion and accumulation of toxic metabolites. E.coli cel ls can also use sugars such as glycerol and glucose as carbon or energy sources. When the E.coli cells use these sugars as carbon sources, they will produce acetic acid and therefore lower the medium pH. Carefully balancing the sugar contents, and aeration conditions can maintain the culture medium pH near E.coli optimum growth pH or within the range of the three pH units. Low aeration conditions lead the cells to produce acids. High aeration conditions allow the cells to use organic acids as carbon source and increase medium pH. Selected aeration conditions can also help cells maintain its medium pH. Do your data on absorbance at 660nm correlate with the cfu/ml and biomass data? Explain. The data on the absorbance at 660nm correlates with cfu/ml as a lower OD660nm gives a high cfu/ml and vice versa. But the data of absorbance does not correlate with the biomass. Despite the inherent inaccuracy of the method, if the procedure is adequately controlled and calibrated the estimation of microbial numbers by optical density should be sufficiently accurate for use in preparing inoculum for cfu/ml testing. Would you expect to obtain the same data if you were to scale up the experiment using a 1000L fermenter? Explain your answer. No, as the size and volume of the fermentor increases, the volume and density of the E.coli culture will increase too so the CFU/ml will also increase.

Morals and Ethics of Cloning :: Argumentative Persuasive Topics

Morals and Ethics of Cloning Cloning is the process of taking cells from a donor, placing them in a culture dish where the nutrients are   minimal, so the cells stop dividing and switch their "active genes". The cells are then put next to an unfertilized egg. The nucleus is sucked out of the egg leaving an empty egg cell containing all the cellular machinery necessary to produce an embryo. An electric shock is used to fuse the egg and cell together. A second shock is then used to mimic the act of fertilization and help begin cell division. After the egg has successfully moved to the stage of an embryo it is then placed in to the uterus of a surrogate mother. When born, all the genes are the same as the donor of the cell. In 1997 Dr. Ian Wilmut, a British scientist successfully cloned a sheep named Dolly.   This turned the scientific world upside-down. The success of the experiment is considered by all as an amazing achievement in science. However, ethics and morals must surface to regulate cloning. It is understood that individuality is the most important part of life. Individuality is given to a person at birth and considered a right they will have for rest of their life. There is also a fear that the clone may only be produced to live the life of the clone, thus causing severe emotional damage as well pain and suffering for the clone. The progression of the clone may be limited, the advance in idea development will slowly die off. Evolution could come to a halt, because with clones, diversity will be limited and there will not be as many advances in society. The cells, in all humans, will all be the same and there will not be a process of natural selection and diversity. Another controversial question facing the cloning process is: How will the clones be treated? The emotions of the clones need to be taken in to consideration, after all they are humans too. "What is common to these various views, however, is a shared understanding that being a 'person' is different from being the manipulated 'object' of other peoples desires and expectations"(Biomedical Ethics).   People, as clones, will be studied, prodded, and poked which in turn will cause much unwanted anxiety and emotional distress.   There will also be problems with relationships between parents and the clone for understandable reasons.

The effect gases derived from fossil fuel combustion have on the Biosph

The year is 2985; we begin with the life of Elizabeth Ferguson. Elizabeth wakes up and begins her day; she took off her stationary nighttime breathing apparatus and attached her portable apparatus and fills a spare tank to hold her oxygen ration for the day. She begins her morning jog, marveling in the ambrosial sight of the vivid, swirling yellow sky, the sky was miraculously clear today and she could fathom the faint blue haze that she had once seen in her childhood â€Å"a classic sign of pollution† these words rang out in her mind as clearly as bells chime, she immediately reminisced upon her many professors who had drilled this fact into her mind ever since she could remember. Her mother’s tales were leagues apart from the professor’s lessons, her mother often conveyed the blue skies of her childhood, the lack of swarms of flying matter too small to be distinguished by the human eye but dense enough to be seen as a thick mist, she also spoke of the time in w hich the breathing apparatuses that were issued to us were unneeded as you could breathe the air without a mask without adverse effects. Elizabeth often shared her mother’s stories with her fellow peers in class. These stories were swiftly recanted by her professors as simply old wives tales. Later, she returned home after the jog and began the sanitation process, removing the particulate matter that had created a fine covering of dust over her skin, she knows that this is one of the most important processes and that if it is not completed swiftly she will be bedridden with many melanomas from the toxic film. After her sanitization she adorns herself in the coverings that will protect her from the rain that is forecasted for today. Rain is one of the most dangerous substances ... ...hat will take the Earth millions of years to filter. These gases, all released through natural tectonic and chemical reactions within and on the surface of the Earth Carbon dioxide and sulfur dioxide both released through volcanoes and particulate matter through the burning of matter. These gases, while necessary to sustain the biospheres homeostatic state are being released into the biosphere at a far greater rate than the earth can sustain the symbiotic recycling methods that have been built up since the earth’s formation 4.7 ±.1 billion years ago via the combustion of fossil fuels. If our behavior as energy consumers on Earth, our only home, the only home for not only us but the entire animal kingdom will become a desolate, uninhabitable rock floating drearily throughout space a shadow of its past glory. Would you want your children to live in Elizabeth’s world?

The benefits of sward renewal

Philip Creightonl, Michael O'Donovan2 and Laurence Sha11002 Grassland Science Research Department Animal ; Grassland Research and Innovation Centre Teagasc Athenry and Moorepark2 Introduction Grassland in Ireland including rough grazing accounts for over 90% of agricultural land use. Lolium perenne (Perennial ryegrass) is by far the most widely sown grass species accounting for over 95% of forage grass seed sold each year. It produces a dense sward, highly acceptable to livestock with the ability to produce high dry atter yields, especially in spring and autumn reducing the seasonality of production.Achieving good performance from grass is dependent on having high quality perennial ryegrass/clover swards. This paper will outline the important aspects of reseeding pasture, what's happening at farm level, why and when reseeding should be completed, its benefits and costs. What is happening at farm level? A recent survey of a proportion of co-op suppliers from Kerry, Connaught Gold and Glanbia (Creighton et al. , 2011) found a number of significant findings from a eseeding perspective, these are listed below. i. v'. ‘x.Regular reseeding took place on 50% of participants farms, 25% reseed infrequently, 25% never reseed. Of those reseeding, 50% of participants reseed 2-4ha/year, 20% 8. 0 Soil K Index 2 3 4 Soil K ranges (mg/ 0-50 51-100 101-150 > 150 K application rate (kg/ha) 110 75 50 Slurry is a good option to maintain nutrient status. With the increased cost of compounds (P and K) slurry should be used in reseeding, 1000 gallons of slurry at 7% DM is equivalent to 4kg N, 3kg P and 19. 5kg K. At soil index 3, slurry (3000gals/ac) is sufficient to supply the P and K nutrients.Weed control The best time to control docks and all other weeds is after reseeding. By using a post emergence spray seedling weeds can be destroyed before they properly develop and establish root stocks. Established weeds can seriously reduce the yield potential and economic lifetime of the reseeded sward. From the survey information it is clear that only 50% of farmers are applying a post emergence spray, resulting in over 90% of surveyed farms having problems with dock infestations.To ensure that a post emergence spray can be applied reseeding should be targeted for the spring or early autumn when establishment conditions are much more suitable and the opportunity for weed control is guaranteed. The post emergence spray should be applied approximately 6 weeks after establishment Just before the first grazing takes place. With weed control it pays to be proactive, spraying when grass is at the two leaf stage works well. Grazing management of reseeded swards Care needs to be taken when grazing newly reseeded swards.The sward should be razed as soon as the new grass plants roots are strong enough to withstand grazing (root stays anchored in the ground when pulled). Early grazing is important to allow light to the base of the plant to encourage tillering. Light graz ing by animals such as calves, weanlings or sheep is preferred as ground conditions may still be somewhat fragile depending on establishment method used. Grazing new reseeds with larger animals can create high levels of tiller pulling. The first grazing of a new reseed can be completed at pre grazing yields of 600-1000kg DM/ha. Frequent grazing of the reseeds at light covers (