The Life Cycle Of Physarum Polycephalum

The Life Cycle Of Physarum Polycephalum In this practical, the life cycle of Physarum polycephalum is being studied. Slime Moulds refers to a wide range of several groups of different and controversial classifications. They have certain characteristics similar to those of animals, plants and fungi. Slimed moulds live in dark, moist habitats where there is abundance of food. They eat bacteria, protozoans, yeasts, fungi, decaying organic materials, and other microorganisms. They are mostly found in forests and lawns, under rotting logs and leaves. Cellular slime moulds live in moist soil or manure. Both types of the slime moulds move across their habitats using amoeboid movement, ingesting food by the process of phagocytosis, a form of endocytosis. Slime moulds may also use chemotaxis, following the chemical gradient given off by their food sources, to find food. Chemotaxis is used by cellular slime moulds when they aggregate. The cellular and plasmodial slime moulds have a motile phase when growth and ingestion of food occurs and an immotile reproductive phase, and they differ mainly in the motile phase. Plasmodial slime moulds begin as gamete cells that are either flagellated or amoeboid that fuses together and forms a zygote. The zygotes nucleus divides, but no cell walls form, resulting in a single celled multinucleate plasmodium that grows as the organism feeds and the nuclei continues to divide. The plasmodium moves in amoeboid fashion using cytoplasmic streaming in order to find favourable conditions and food, and may move several feet in a single day. The plasmodium continues to feed along as conditions are good, but when food runs short or its habitat becomes to dry, the plasmodium changes into a fruiting body, the next phrase in its life cycle it hardens and produces stalked sporangia that contain spores, often after moving to a drier or better lit location. The spores are released and will devel op into gametes to begin the life cycle again. There are four main stages in slime moulds which are vegative, aggregation, migration and culmination. In the vegetative stage, a slime mould is single and is known as amoeba and this will eat bacteria. In this case of this practical, the bacterium fed to the slime mould is the Physarum polycephalum. After the food preferences of the single cell are partially completed or most of the food preferences are completed, the slime mould will moved to its next stage of the life cycle which is known as the aggregation cycle. In this stage, a slime mould will reproduce and secrete cyclic AMP. Cyclic AMP will attract neighbouring cells together. As single celled slime moulds come into contact they will stick together through glycoprotein adhesion molecules. Once enough slime moulds have been attached to each other, they will move onto the next stage of the life cycle which is known as the migration stage. The multitude of slime moulds will form what is known as slugs. The slug is able to move towards heat and light. However, the cell in the slug will differentiate into two types of cell and they are both known as the prestalk and prespore cells. The prestalk cells will move towards the anterior end of the slug and the prespore cells will move towards the posterior end of the slug. The slug will then start to produce a fruiting body out of prestalk cells on the anterior end of the slug. However, it also starts to form spores out of prespore cells at the posterior end of the slug. This is when the posterior end of the slug will start to spread out as the anterior end of the slug starts to rise up into the air. This is when the last stage of the slime moulds cell cycle begins known as the culmination stage. The prestalk cells will form the base the form of the fruiting body. The pretalk cells form the cellulose stalk tube. The cellulose stalk tube pushes prespore cells to the top towards the fruiting body. This process will take around 8-10 hours and ends with a good fruiting body releasing mature spores that will become the single celled slime mould. The purpose of this practical is to examine the life cycle of the slime mould using the different food preferences. Each stage should be observed and recorded. This practical will force the slime moulds through each stage of the slime mould life cycle and a mature spores will be observed at the end of this practical. Method This practical started by preparing the petri dishes. This proportion of this procedure was done by the demonstrators. During this practical, I was provided with some phyrasum a genus of mycetozan slime moulds, and this was to investigate the different food preferences on chemotaxic behaviour. First of all I was provided with two agar plates one with water with no nutrient levels and the other second agar plate with corn meal agar with low nutrient levels. After the petri dishes were prepared, the next procedure was to inoculate the plates. The materials that I used for this procedure was an inoculated loop, and this was done by sterilising the loop over an open flame until the loop was red. Using the loop I removed a small piece of the slime mould with agar from the advancing margin (edge of the growth) and placed into the middle of the plate onto the two agar plates one with the water and one with the corn meal agar and streaked it onto the petri dishes. The water agar plate was the experimental where I had to put some food preferences; the corn meal agar plate was to be inoculated without any food to observe the cytoplasmic streaming for the following day. In the water agar plate, there was combination of food preferences including apple, chocolate, raising and jelly babies. I added one of each of the food and which was already cut and placed them in each of the corner near to the slime mould, and then both of the agar plates were incubated at 20oC for 12 hours, and they were observed using a dissecting microscope using the x40 magnification. Results Which food had the most growth and which type of food was most visible Different food choices Amount of growth chocolate Growth was quite visible was spreading Apple No growth at all not visible at all Raisin Big growth was spreading Jelly babies Big growth was spreading around the plate However there were not many results for this practical. Once the slime mould had food preferences containing a type of food source the cell together aggregated together to form a growth in the slime mould. In the plate with food sources there was a mixture of stalks with spores. However, in relation to this result Chocolate, Raisin, and jelly babies had the most growth and this was quite visible and was spreading around the plate and the growth was very visible and was being seen clearly. However, the majority of the agar plate with the food preferences in was covered in fruiting body as food preferences was placed all-round the plates and they were all spread out. This suggests that the food that had a high percentage of sugars the more growth it had, this has shown in my practical, however apple had the least growth as it mainly because it was sweeter than sugar and mainly its a fruit and dries up quickly and changes it colour so maybe thats the reason why it didnt show any growth at all. Discussion As both of the agar plates were incubated for 12 hours, and was at the temperature 20oC, the slime mould didnt develop through its life cycle as it was expected, which means it didnt achieve the purpose of my practical, as there were only growth near the food choices of chocolate and raisins, and only achieved the first stage of the life cycle, which was the vegetative stage. The vegetative stage was observed and recorded. The spores were quite visible on the petri dishes and they started to grow and eat the bacteria where the food preferences were placed. However, the observations shows us that the agar plate the corn plate without the food preferences added, the slime mould will aggregate together and move to the nearest food preferences that are available, so it can form a fruiting body, and create spores to hard and different environments. If unfavourable conditions had been a factor, the amoeba may have formed cysts rather than producing a fruiting body. However, the introduction of other factors on different plates of slime moulds may have possibly altered the differentiation of the growth of the slime mould. However, it is quite hard to tell since the slime mould was only kept for 12 hours and kept under room temperature and also kept on optimum conditions at all times.

Netflix – Essay

Identify key issues, problems and opportunities facing Nettles. It may be helpful to consider the fact that the Nettles business model evolved through many strategy revisions. What caused them to make each shift? Were the shifts driven from the top or bottom? Is this easier for a small or large company? The key issue that was facing Nettles early on was the selective market of people that were into the DVD market. Most were still with VS. market at this time and it gave them a small problem during start-up.But, with that changing market they new that consumers will soon turn to DVD's and leave behind their old technology of VS.. They also faced the problem of most Blockbuster being a 10 minute drive from at least 70% of U. S. Populated homes. This makes their whole sales pitch of people not having to leave their homes to rent movies even harder due to the number of available Blockbusters. With Nettles no late fee policy this made it easier for them to get more sales because Blockbust er charged late fees.Also, they came across the problem of half the movies they shipped were the new releases. This made under stocking when customers wanted them and overstocking when the movie was not new anymore. They fixed this problem by making the recommended movies for consumers because this expanded their horizons on other movies other then the new ones. They also had a distribution problem because they only had one distribution center. All these shifts were driven from the top. With the growing customers and profits they have learned what consumers wanted.They held surveys to find out what movie a customer wants and the movie recommendation system helped expand the nonuser's movie choices. They even got special packages and were tied into the USPS for their delivery services that got perfected over time. This Is easier for them as they became a large company and made deals and expanded with the profit and knowledge they had about customers from their surveys. (B) How did di sruptive versus incremental innovations play out in the Nettles versus Blockbuster story? Is VOID disruptive or incremental? What roll does diffusion of innovation and adopter categories play?Timing of entry? Disruptive Innovation played a role In the beginning and start-up for Nettles. When they first opened and should to the DVD population this was disruptive. From then on they made incremental innovations along the way from the video recommendations to the shipping services. These were smaller steps done from learning from customers and growing in popularity. Also, their growing profits made innovation easier and affordable for the company. VOID Is disruptive Innovation because It Is a totally new marketing approach by the company.VOID was not a spin off of there DVD rental service It was a totally new approach for the company to take. This would require for the company to have different marketing for VOID and a new concept of nothing through the mean, instead it's all online. Di ffusion of innovation came along when Nettles went into the VOID services. They were one of the innovators of this but shortly after they had many companies patting v I Nils mace It very competitive Ana Nora to De cutlets Decease other companies only did VOID and Nettles was not known for that service.Also, the time of entry for the other business was good because Nettles was not that successful introducing it to the market that when the competitors advertised they got more business then Nettles. (C) Using only the information provided in the case, evaluate alternative approaches to the current problem (VOID), and VOID had the problem of not being able to provide high quality video to the customer as do the cable companies. This problem is hard to fix because it will have to mean changing around Nettles servers to higher quality servers to stream movies n high-definition.Another problem they had was people can not play the movies on their TV but, instead only on their laptops or de sktops. The only was customers can play the movies on their TV's is if they buy either a ERG, S-Video, or HIDE cable so they can project the movie from the laptop to the TV. But, with this means that customers will have to go out and make a purchase to Just watch online movies on the TV. The solution to this problem would be is Nettles provided the cable needed to watch the movies from the computer to the TV for a low rental fee.As long as they have a Nettles VOID account they can pay a one time rental fee for a cable as long as they stay with the company. (D) Select the best alternative. Your choice should be supported by sound arguments and be realistic given the firm's resources. I feel that the best alternative for Nettles is to keep their rental services and also have the VOID services. I feel that both are very profitable services they can provide to customers. They have such a large customer base that they can pick up on shifts in the market.Nettles has been proven o make bot h incremental and disruptive innovation to help their company grow. Even my Android phone has Nettles on it that allows me to stream videos directly to my phone anywhere there is Wi-If. If the market turns to more VOID then Nettles will make that shift and turn their company into a VOID company. But, if it doesn't they still have their rental services for profit. Their rental services cost the most to up- keep because of all the workers and distributed facilities they need to keep up with the demand. VOID has a lot less running fees. They can greatly cut down on employees and facilities.

Describe why schools have policies and procedures Essay

Identify the main types of state and independent schools and describe the characteristics of different types of schools in relation to educational stages and school governance. The majority of state funded schools are maintained by local authorities and follow the national curriculum, national pay and conditions, they are overseen by local authority. The differences over state schools are who their staff, who owns the land and buildings and who controls admissions for example. Community schools are run by local authority and the local authorities employs the staff, owns the land and buildings and decide the admission policy. However, foundation and trust schools are run by the governing body but are maintained by local authority. They employ their own staff and decide their own admissions policy and the land and building are usually owned by the governing body or charity and is non-profitable. Both examples follow the national curriculum and the educational key stages. Key stage 1: 3-5 yrs Key stage 2: 5-7 yrs Key stage 3&4: 11-16 yrs Key stage 5: 16-18yrs Every state school has a governing body, the type and size of the school will decide the size of the governing body. The responsibilities vary for example community schools governing body consists of a specific number of governors for various categories, the following categories are parent governor, staff governor, authority governor and community governor. Foundation and trust schools usually decide their own governing body. Both have the role of monitoring schools process and setting targets. So basically they are both state school, but local authority runs community and foundation and run by governing body but maintained my LEA. Independent schools are not maintained by local authority or central government, they do not have to follow national curriculum but most choose to do so. The head and the governors decide on admission policies and staffing and the framework and structure of the school, they are obliged to register with the DfE so they can be monitored by ISI. They are profit  running schools and some have charitable status so they can apply for tax relief. Most independent schools educational stages are as follows: Prep school: 4-11yrs Senior school: 11-16yrs Sixth form: 16-18yrs The different types of independent schools are based on where the schools funding comes from for example. Parochial schools are mostly funded by religious groups and managed by the religious institution to which they belong. The schools are usually governed by interim executive board of governors where they have foundation governors which are appointed by the religion they are associated with. One of the main missions would be to teach the religion the school is associated with. Whereas proprietary or private career schools they are profit based schools and the schools directors are not ruled by the governing body if they choose to have a governing body. The main mission for these schools would be occupationally related education and market related. Whereas if proprietary school choose to have a governing body it is a limited system of governance, they are chosen by the governing body there and the proprietor with the proprietor having the final say in all matters.

Kate Spade Case - Free Essay Example

Sample details Pages: 2 Words: 630 Downloads: 3 Date added: 2017/09/22 Category Advertising Essay Type Argumentative essay Did you like this example? Critical Issue: Which options should Kate Spade take? As the company has become bigger and its financial results were very strong, the team had begun to feel pressured to take the company next level. One of the team member felt that they were losing their control little by little since they had not ready for handling this issue yet. The team wanted to someone who was experienced and could manage developing team to next level. When Kate Spade was looking for some helps, Kate Spade was faced with offers from number of buyers, and what Kate Spade really needed was strategic help. In March 1998, the team had to think about four offers and decide which option the team should take for its company growth. Those four offers had important factors for Kate Spade to grown in the future. In order to make a decision there were three important factors which were really important to make their decision. Those were in Option A, B and C. Factors Option A: â€Å"No perfect person for CEO s lot† This investment bank offered company’s 40% of share on a post-money valuation $40millinon, and this company sounds great, and it had great ability to manage financial task. However, this company was not aggressive enough to grow Kate Spade in the future. Moreover, what Kate Spade really needed was the person who could help inside its company and take CEO slot. The person who was coming was not experienced enough in fashion industry or could not help Kate Spade to be a big brand. Option B: â€Å"different positioning† This company offered to buy 80% of Kate Spade in return for company stock. This company had a lot of department stores and specialty retail location in over 80 countries. If they made a contract, Kate Spade could use their useful resource. However, this company’s targeting market was not appropriate for Kate Spade. Their target price range was quite lower than Kate Spade was. Lowering the level of target was not the growing company should do and one of team member thought that this trade seemed look down on the team. Option C: â€Å"earn-out† This option offered to buy 100% of Kate Spade for $70 million. Plus this company owned three large manufacturing facilities around New York City, and had wide spread distributions. However, this deal consisted of 30% of in cash up front and an earn-out provision over the next three years for remaining 70%. This was not fair price for the team, because the team would be paid on the valuation only three years period even though that they would work really hard. This was not completely fair to the team. Solution In order to make decision, those three factors were very important for Kate Spade not to choose those three options. Those three factors were not appropriate for Kate Spade for growing to next level. The solution here is to take the option D, even though that there was put and call rights which the team member really disagreed it or Brosnahan felt uncomfort able to be in the huge company, there was a great chance to expand Kate Spade. Since this buyer was high-end specialty retailer and it operated its own department store in many states offering many kinds of product lines, it knew how to manage growing the company and already had customers. Kate Spade really needed to go up next level and this company had ability to Kate Spade to take next level, so this company had a perfect spot. Some of the ambiguous questions about this trade like how much control do they want, private label, design, or employee issue, the team can negotiate and discuss about those things with this company. This company had strategies to grow the business and make Kate Spade be a bigger brand. Don’t waste time! Our writers will create an original "Kate Spade Case" essay for you Create order