Utilizing Pumpkins as a “Reverse” Trap Crop Essay Example

Utilizing Pumpkins as a â€Å"Reverse† Trap Crop Essay In the world of agriculture, trap crops are normally used to lure pests away from a commercial crop by presenting the pest with a more attractive alternative. But when conducting research to develop new seed traits that provide better yield, drought resistance, or even insect resistance, trap crops can be used to test the performance of a new trait.The western corn rootworm beetle (Diabrotica virgifera virgifera) causes billions of dollars in damage to corn crops throughout the United States each year. Recent seed research has helped develop new corn varieties to combat this problem. These new varieties of corn have a protein (Bt protein) that causes stomach distress in adult western corn rootworm beetles that result in death. Thus, the pest resistance is literally bred into the seed, eliminating the need for harmful pesticides. This type of corn is considered to be rootworm resistant.Normally, in order to be able to â€Å"test† the performance of a specific rootworm resistant corn variety, a test plot has to be infested with western corn rootworm eggs manually. This tends to be costly and very labor intensive. The infested eggs then develop into larva, which feed on underground roots. Adult rootworms feed on the above ground tissue of the corn plant. Both the roots and the above ground tissue contain the Bt protein. The corn plant is then â€Å"harvested† prior to the pollination period in a process called a â€Å"root dig†.During a ‘root dig† the corn plant is cut off at approximately two feet above the ground, the roots are dug up and rinsed with a high power stream of water to expose the roots which are then rated for damage by the corn rootworm larva. Based on the data collected during the â€Å"root dig†, researchers are able to evaluate the effectiveness of the resistance that is bred into that variety of corn. Root dig washing process is shown in picture on the left. Diagram of corn root damage by corn rootworm be etles is shown in picture on the right.HYPOTHESIS: What if one could utilize a â€Å"trap crop† to entice the adult western corn rootworm beetle to a test plot, allowing the adults to feed and eventually lay their eggs? I predict that by adding pumpkins (independent variable) as a trap crop in rootworm resistant corn will allow for a greater number of eggs (dependent variable) to be deposited in the test plot naturally versus the rootworm resistant corn without the trap crop, therefore eliminating the need for manual infestation.To test this hypothesis, we selected pumpkins to plant as a trap crop in a one acre square plot containing rootworm resistant corn. This would be the independent variable in this experiment. It is known that the adult western corn rootworm beetle is highly attracted to pumpkin vines and flowers. A second test plot of the same size (same farm) would be planted with the same variety of rootworm resistant corn without the pumpkin crop. The dependent vari able would be the egg counts in both test plots. The control in this experiment would be utilizing acreage on the same farm.Special steps were taken to replicate the exact soil conditions by a pre-planting soil analysis; utilizing the same â€Å"batch† of chemical in herbicide spray applications, and the close proximity to each other to control factors such as precipitation, number of days with full sunshine, humidity, etc. This will aid in controlling the experiment’s internal validity and act as a guide in any subsequent replications of this experiment. Adult western corn rootworm beetles are shown on a pumpkin flower in the picture on the left.Damage by rootworm beetles on a mature pumpkin shown in picture on the right. Pumpkins were planted in the test plot # 2 in the spring of 2012 and were allowed to mature naturally. During flowering, a sizable increase in the adult rootworm beetle was observed in test plot #2. Based on the observable increase in adults, we pred icted that there will also be an increase in the number of eggs in said test plot when compared to the number of eggs in the test plot without trap crop (pumpkins). Soil samples will then be collected and analyzed for egg counts.If it is proven that planting a trap crop increases egg counts naturally, there could be a considerable cost savings in the process of evaluating the effectiveness of desirable traits in corn. This experiment was conducted at an agricultural Ramp;D site in northwestern Indiana during the summer of 2012 in preparation for this task. Egg count data has been received and is currently being evaluated in preparation for the 2013 planting season. In preparation for this experiment, several independent scientific papers were reviewed. Sorghum as a Trap Crop for Nezara viridula L. (Heteroptera: Pentatomidae) in Cotton in the Southern United States†, P. G. Tillman (1); â€Å"Case Study: Trap Crop with Pheromone Traps for Suppressing Euschistus servus (Heteropt era: Pentatomidae) in Cotton†, P. G. Tillman and T. E. Cottrell (2) and â€Å"Trap Cropping to Manage Green Vegetable Bug Zezara viridula (L. ) (Hereroptera: Pentatomidae) in Sweet Corn in New Zealand†, James H. Rea, Stephen D. Warren, Richard Sedcole, Peter J. Cameron, Stuart I. Davis, R. Bruce Chapman (3) were considered for background information.These studies were helpful in explaining the commercial use of trap crops as an effective method of removing pests from cash crops and served as a basis for our unique application of a â€Å"reverse† trap crop in testing the effectiveness of ongoing corn research. Testing methods were similar but our research did not include any type of Pheromone study. Our experiment was based on the premise that by planting pumpkins in the test plot (known to attract western corn rootworm beetle), we could naturally increase the numbers of western corn rootworm beetle eggs in that plot.An increase in the number of naturally occurrin g eggs could result in a significant reduction in our annual research expenses. - KEY WORDS:western corn rootworm beetle (Diabrotica virgifera virgifera), trap crop, rootworm resistant corn. - METHODS and MATERIALS: This experiment was conducted at a seed research and development facility in northwestern Indiana during the 2012 growing season in preparation for RINT Task 3.This method of scientific design was chosen because it is a replication of a similar experiment conducted at a research and development facility in Iowa and has shown viable results. It was designed to compare the viability of planting a trap crop to attract the western corn rootworm beetle to evaluate the performance of corn containing rootworm resistant traits from different areas of the Midwest. The acreage, chemicals, sampling tools and laboratory facilities were readily available. In addition, if the hypothesis can be proven to be true, there is a potential for cost savings in other areas of our research.Inse ct Species: Western corn rootworm beetle (Diabrotica virgifera virgifera). Corn rootworm larvae can destroy significant percentages of corn if left untreated. In the United States, current estimates show that 30 million acres (120,000  km? ) of corn (out of 80 million grown) are infested with corn rootworms and that area is expected to grow over the next 20 years. The USDA estimates that corn rootworms cause $1 billion in lost revenue each year, which includes $800 million in yield loss and $200 million in cost of treatment for corn growers (The Dow Chemical Company). (4)Shown above from left to right, corn plant damage in the field and examples of actual root damage done by western corn rootworm beetles in the center and right picture. Healthy roots are shown as a full root system; damaged roots are short to nonexistent. Sampling Technique: Using a golf course cup cutter, take 4† diameter x 4† deep soil core samples. Collect ten (10) core samples per acre (trial area) . Core samples should be taken at various locations within the test plot. Include samples taken from within the corn rows and between rows. Place core samples in individual gallon bags.Be sure to break up any large clumps and remove stalks and other residue. Making the soil as fine as possible will aid in the washing process. Send individual samples to a laboratory with capabilities to wash eggs and provide egg counts. Taking multiple core samples at various locations throughout the test plot and then analyzing all ten (10) samples separately allows for a broader analysis of the entire test plot. The measuring unit of one (1) pint that was chosen for the final sample allows the lab sufficient soil to run the required tests.Once the samples arrive at the laboratory, each individual sample is mixed with a saturated salt solution. A sample of this mixture is then placed on a special microscope slide (Whitlock Universal or Whitlock McMaster). The saturated salt solution makes the rootwo rm eggs float to the top of the mixture in the slide where they are then counted. Data was collected from each individual sample to obtain egg counts for each test plot. EXPERIMENT: Two, one (1) acre test plots were selected at opposite ends of a ten (10) acre field. Soil type, topography, and precipitation were identical.Each plot was measured at 200 ft. wide by 220’ deep and marked off with flags. This is approximately one (1) square acre. Both fallow (empty ground) test plots were plowed utilzing a chisel plow set at a depth of six (6) inches to turn the soil over and prepare the soil for planting. Both test plots were then planted using a four (4) row custom bulk planter and a rootworm resistant variety of corn. The corn rows were spaced 30† apart. The corn seed within the rows was spaced 6† inches apart. Each test plot had a total of 80 rows of corn. Both test plots were also treated with Glyphosate in a concentration of 1. quarts to 15 gallons of water to ki ll any existing weeds. This amount of Glyphosate solution was enough to cover one (1) test plot. It was replicated twice to cover both test plots in the experiment. Once the rootworm resistant corn had been planted in both test plots, a trap crop of pumpkins was also planted throughout the test plot #2 (independent variable), utilizing a custom two (2) row planter. Pumpkin seeds were planted in between the rows of corn, spaced five (5’) feet apart. A cable winder was used to mark off the five (5’) foot increments needed to plant the pumpkins.A cable winder is used with a custom planter and calibrated to â€Å"click† when it is time to manually drop the seed. Both plots were allowed to grow throughout the summer. Visual observations were made in each plot, on the first Monday of each week between July 1st and September 1st to obtain adult rootworm beetle population counts. Ten observations in multiple locations across the test plots were taken each time. Random p umpkin plants were selected to count the total number of adult rootworm beetles in each observation. After harvest, prior to the first hard frost, soil core samples were taken, following the above mentioned sampling procedure.Core samples were then sent to an outside laboratory for analysis. - RESULTS: An increase in adult rootworm beetles was observed in test plot #2 (with pumpkins) when compared to test plot #1 (without pumpkins) but without soil egg count analysis, this data in inconclusive. Solid data is available once soil samples are analyzed for egg counts (dependent variable). Historically more than ten (10) eggs in a pint sample of soil are considered to be a high amount. In 2012, test plot #1 and #2 both showed an average of approximately two (2) eggs per pint sample.Samples taken at four different test sites in Iowa yielded six (6), zero (0), one (1) and four (4) eggs respectively or an average of 2. 75 eggs per pint sample. All data collected is reflecting little to no m easurable increase in the total number of western corn rootworm eggs that are occurring naturally when using a trap crop. Egg Count Core Sample Data for Test Plot #1 and Test Plot #2 Test Plot #1|   |   | Test Plot #2|   | |   |   |   |   | Core Sample #| Egg Count #|   | Core Sample #| Egg Count #| 1| 0|   | 1| 0| 2| 1|   | 2| 3| 3| 0|   | 3| 2| 4| 1|   | 4| 2| 5| 4|   | 5| 3| 6| 3|   | 6| 2| | 2|   | 7| 1| 8| 2|   | 8| 0| 9| 1|   | 9| 2| 10| 0|   | 10| 2| Ave # of Eggs| 1. 4|   | Ave # of Eggs| 1. 7| Egg Counts in Test Plot #1 Compared to Test Plot #2 Number of Eggs/Pint Sample Number of Samples/ One (1) Acre Test Plot - CONCLUSION: Based on the data that was collected, there did not seem to be a significant increase in the number of western corn rootworm eggs occurring naturally in test plot #2 when compared to test plot #1, even though there was an observable increase in adult western corn rootworm beetles in test plot #2.Where test plot #2 contained the trap crop (independent variable) and test plot #1 that did not contain a trap crop (dependant variable) in a single ten (10) acre test strip (constant variable). After carefully analyzing the data that was collected during this experiment, I have concluded that the introduction of a trap crop (pumpkins) to attract adult western rootworm beetles in rootworm resistant corn does not significantly increase naturally occurring corn rootworm beetle eggs. This data disproves my hypothesis that it would significantly increase the number of naturally occurring eggs.No cost savings can be associated with this experiment and conventional infestation methods are just as effective as this experimental method. DESIGN AND REPLICATION: The experimental design to test this hypothesis was constructed with ease of replication in mind. It utilizes simple techniques and materials that are readily available at most seed research and development sites. If the design is poor or if proper samp ling procedures are not followed then data in the experiment can be skewed, resulting in unreliable data.Based on potential cost savings in research, unreliable data can be an expensive mistake. In addition, if the design is well done, an increase of reliable data is shown time and time again with the same results. Replication is so important because it gives validity to the experiment’s results. As the same data shows the same results and the same conclusions over multiple replications, that data can become accepted as scientific fact. REFERENCES: (1) http://www. ars. usda. gov/sp2UserFiles/person/5648/PDF/ARIS 8-Sorghum as a Trap Crop for SGSB. d Tillman, P. G. 2006. Sorghum as a trap crop for Nezara viridula L. (Heteroptera: Pentatomidae) in cotton in the southern United States. Environmental Entomology. 35(3):771-783. (2) http://www. hindawi. com/journals/psyche/aip/401703 Tillman, P. G. , Cottrell, T. E. 2012. Case Study: Trap crop with pheromone traps for suppressing eu schistus servus (Heteroptera: Pentatomidae) in cotton. Psyche. DOI: 10. 1155/2012/401703. (3) http://onlinelibrary. wiley. com/doi/10. 1046/j. 1461-9563. 2002. 00130. x/full Rea, J.H. , Wratten, S. D. , Sedcole, R. , Cameron, P. J. , Davis, S. I. and Chapman, R. B. (2002), Trap cropping to manage green vegetable bug Nezara virdula (L. ) (Heteroptera: Pentatomidae) in sweet corn in New Zealand. Agricultural and Forest Entomology, 4: 101-107. doi: 10. 1046/j. 1461 (4) http://en. wikipedia. org/wiki/Diabrotica_virgifera; The Dow Chemical Company. Product Safety Assessment (PSA): Herculex RW Rootworm Protection. September 26, 2006. URL: http://www. dow. com/productsafety/finder/herculex. htm.

Free Essays on Teenage Pregnancy

As today’s family values slowly decline, teenage pregnancy becomes a major concern in today's society. Each year teenage girls are getting pregnant at a younger and younger age with no guarantee of a father by their side. Many girls are left with the responsibility of supporting young children financially, and many girls aren’t even ready for the responsibility of caring for another human being. As far as I am concerned, this family issue is very interesting because the teenage parent has a lot of challenges that must be overcame and decided. The two main ones are continuing education, and financial problems. Pregnant teenagers have the right to finish their education. It may be hard, but it is not impossible. The outcome of teenage pregnancy turns out better if the mother goes back to school after she has given birth. Staying in school may help to prevent teenage mothers from having a second pregnancy. In some schools they stay in their regular classes, but in others they are placed in special classes for pregnant teenagers. These classes’ help parents learn about pregnancy, prenatal care, and parenting skills. Some schools even have childcare. Schools that provide daycare centers on campus reduce the incidence of teenagers dropping out of school. These school programs also decrease the likelihood that the teen mother will have more children. It is important for teenage parents to complete high school. A lot of jobs require high school diplomas. The statistics show that teenagers who dropout usually work minimum wage jobs in the community. Having a high school diploma enables them to have more career choices. The other most important challenge of a teenage parent is financial problems. Teenagers face more financial problems than older parents. Even if both parents work, they lack the education or skills needed to obtain a job that can support a family. This is why many teen mothers rely on welfare. Many teen parents ... Free Essays on Teenage Pregnancy Free Essays on Teenage Pregnancy I’m quite sure most of us came back to school in August thinking, â€Å"Dang! Some people had a very interesting summer.† I don’t know how it was for you guys, but every time I turned around I saw a new face, a new expecting mother. This article is not written to offend or criticize anyone, but it is meant to inform students of the risks and responsibilities of teen pregnancy. Every year, nearly one million teen girls get pregnant. At first I thought that girls just â€Å"slipped up†, but after asking for the opinions of several students and staff members, I have learned that most teen pregnancies are planned. According to the National Campaign to Prevent Teen Pregnancy, almost 60% of teen pregnancies are intended. Of that percentage, more than half of teen mothers cite emotional void as the reason they became pregnant. P.E. Instructor Sherry Jackson said, â€Å"Pregnancy at Thornridge High School is a competition to fill a void. Some girls are not receiving the love and attention they require and are therefore turning to pregnancy as a solution.† Senior Jennifer Stazzone said, â€Å"In some situations, girls have kids because they want that feeling of being loved or they want someone to love. This happens because they may not get that kind of attention from their parents, and they feel like it’s them against the world. Girls also get pregnant to keep the guy they’re with.† Of the remaining teen mothers whose pregnancies are intended, 40% cite a desire to hold on to the baby’s father as the reason they got pregnant. Fact #1: Sex won’t make him yours, and a baby won’t make him stay. Not only does getting pregnant result in having a child, but it could result in medical problems including, but not limited to, poor weight gain, pregnancy-induced hypertension, anemia, sexual transmitted diseases, and even death. It has been proven that teens experience a maternal death rate 2.5 times greater than t... Free Essays on Teenage Pregnancy As today’s family values slowly decline, teenage pregnancy becomes a major concern in today's society. Each year teenage girls are getting pregnant at a younger and younger age with no guarantee of a father by their side. Many girls are left with the responsibility of supporting young children financially, and many girls aren’t even ready for the responsibility of caring for another human being. As far as I am concerned, this family issue is very interesting because the teenage parent has a lot of challenges that must be overcame and decided. The two main ones are continuing education, and financial problems. Pregnant teenagers have the right to finish their education. It may be hard, but it is not impossible. The outcome of teenage pregnancy turns out better if the mother goes back to school after she has given birth. Staying in school may help to prevent teenage mothers from having a second pregnancy. In some schools they stay in their regular classes, but in others they are placed in special classes for pregnant teenagers. These classes’ help parents learn about pregnancy, prenatal care, and parenting skills. Some schools even have childcare. Schools that provide daycare centers on campus reduce the incidence of teenagers dropping out of school. These school programs also decrease the likelihood that the teen mother will have more children. It is important for teenage parents to complete high school. A lot of jobs require high school diplomas. The statistics show that teenagers who dropout usually work minimum wage jobs in the community. Having a high school diploma enables them to have more career choices. The other most important challenge of a teenage parent is financial problems. Teenagers face more financial problems than older parents. Even if both parents work, they lack the education or skills needed to obtain a job that can support a family. This is why many teen mothers rely on welfare. Many teen parents ...

Branches of Government Paper Essay Example | Topics and Well Written Essays - 500 words

Branches of Government Paper - Essay Example This principle of the separation of powers is embedded in the American system of checks and balances. The system is quite a complex set-up but has amazingly worked for the past centuries since this country gained its independence from its former colonial master (Hargrove, 2000, p. 8). Main Benefits – besides safeguarding democracy and freedom in the new nation by ensuring no one individual gains absolute political power, each of the three branches are also independent and co-equal from each other. In other words, the three branches which are the executive, legislative and judicial branches can check and balance on the other two branches. It was the great French political philosopher and social commentator Montesquieu who gave the founding fathers this idea of separation of powers as a preventive measure against abuses and some critics of this system had said it had led to periods of political paralysis in which an agenda of the government cannot be pursued due to blocks within this system. The main benefit of this separation of powers through checks and balances is that all three branches are encouraged to do their best in performing their duties and responsibilities least they be criticized and censured by the other two branches of the government.

Story Essay Example | Topics and Well Written Essays - 250 words - 5

Story - Essay Example But the plagiarism was just too much to be ignored. There were entire passages and paragraphs that had been copy-pasted from the web. Jason Blair was a rising journalist in 2003 (Bailey). He was rendering his services to the New York Times as a reporter. Everything was going fine until one day, an editor at the San Antonio Express-News found out certain common things between a column written by Blair and a previous report authored by Macarena Hernandez. This led to the starting of an investigation by the Times into Blair. As a result of the investigation, 36 out of the total of 73 articles written by Blair were found to contain fabrication, plagiarism, or some other kind of unethical behavior (Bailey). Blair was left with no option but to resign from his job as a reporter and a journalist from the New York Times. Bailey, Jonathan. â€Å"5 Famous Plagiarists: Where Are They Now?† Plagiarism Today. 21 Aug. 2012. Web. 16 Apr. 2015. . Grimes, A. C. â€Å"5 Insanely Blatant Acts of Plagiarism by Famous People.† 18 Feb. 2014. Web. 16 Apr. 2015.

Reform Laws and Divorce Essay Example | Topics and Well Written Essays - 1500 words

Reform Laws and Divorce - Essay Example This paper shall argue on the causes of divorce, while pointing out to the reasons for reform laws on marriages and divorce in the process. A marriage is a standard union between two individuals that are committed to one another and they are to live for each other with the two parties developing common interest, which are economically related in some cases. In marriage, the husband and wife are expected to have a lifetime bond and the strength of this bond all depends on how they could effectively manage their relationship and it is the mismanagement of relationships that ultimately lead to divorce. It is a known fact that most of the divorce cases are filed by women and this is due to the fact that the society has made women to play second fiddle in relationships and when they feel they are no longer enjoying the relationship, they sue for divorce. According to the American Law and Economics Review, more than two-thirds of divorce cases in the United States are filed by women (Brini g & Douglas 126, Khun & John 31) A marriage would surely stand on a proper economic foundation and if the necessary things are not done, the foundation on which the marriage was built would collapse. This is to say that a marriage that the husband or the man of the house cannot meet up with the responsibility in the house in terms of matching his income with the finances at home would begin to crumble. A relationship that is marred by lack of finances or proper management of finance cannot stand and the marriage would ultimately fail. In this case, there needs to be some reform laws on the union of two people as it must be clearly stated that people that are not financially capable to start a family should not even make any attempt to get married in the first place. If this is done, divorce cases that arise as a result of the inability of the husband to cater for the financial needs of the family would never arise (Brinig & Douglas 127). There are several divorce situations that the bride accuses her husband of not being financially capable enough to cater for the family and then sues for divorce and after the hearing of the divorce, the two married parties are legally separated with the husband paying some sum of money for the upkeep of his ex-wife and if they have any issue between them, he is also responsible for the upkeep of the children. Thus, if there have been reform laws that have mandated the wife to ensure that she wants to get married to someone that would take care of the finances of herself and the issue that comes after the marriage, these cases of divorce would be to the barest minimum. Parents hold the responsibility of catering for their children and when this obligation is not fulfilled there could be some cracks in the walls in the family system and this could be the effect of an improperly planned marriage system. Divorce follows an improperly managed marriage, thus there should be some reforms law that seeks to monitor the management of m arriages and this would go a long way to teach the couples the consequences of mismanaging their homes. Some of the reasons women sue for divorce is due to the financial and economical incentives they stand to gain from the dissolution of their marriage and the fact that it is the women that gain more from

Additive Manufacturing; Stereolithography in Dentistry

Additive Manufacturing; Stereolithography in Dentistry Introduction: Digital revolution because of computers has made the previously manual tasks much easier, faster and more reliable at a reduced cost. Such modifications are always welcomed in dentistry, especially from materials and manufacturing perspective. The digital revolution in the form of dental CAD–CAM took place many years ago, since than many modified systems have appeared on the market with great rapidity. It is expected that another digital dental revolution will take over dentistry in the form of layered fabrication techniques, once they are able to produce high quality dental prostheses. This situation has also posed great challenge for the material scientists in the form of materials that are suitable for long term use in dentistry and oral environment. This can potentially take dental materials research in a totally different direction. Additive manufacturing: Dentistry is the most suited field for additive manufacturing, as it is associated with rapid production of customized units made to fit the patient with high degree of precision and accuracy. In principle it creates a series of cross-sectional slices from a 3D computer file which are then printed one on top of the other to create the 3D object without any material being wasted. Additive manufacturing technologies includes many and Stereolithography (SLA) is one of them. Stereolithography (SLA) Stereolithography (SLA) is the most widely used rapid prototyping technology. The term â€Å"Stereolithography† was first introduced in 1986 by Charles W. Hull, who defined it as a method for making solid objects by successively printing thin layers of an ultraviolet curable material, one on top of the other. Materials and Required time: A number of materials that the industry uses have increased greatly and modern machines can utilize a broad array of photo curable polymers. Timing depends on the size and number of objects being created, the laser might take a minute or two for each layer (a typical run 6 to 12 h). One can now even print 50 to 80 dental crown units in 56 minutes with high quality mode. Applications in dentistry: Dental applications are very suitable for processing by means of SLA due to their complex geometries, low volume and strong individualization. Most common are models fabricated from intraoral or impression scans. However, popularity is gaining for orthodontics and removable prosthodontics. 1. Production of anatomical models: SLA models are preferred because of higher strength, higher temperature resistance, lower moisture absorption, and lower shrinkage. They can be sterilized for surgical use, and literature has shown superior accuracy (Barker et al., 1994, Choi et al., 2002, Cunningham et al., 2005). Table-1 summarizes basic characteristics of the three most common types of 3-D models used in the United States. SLA clinical models are used as an aid to diagnosis, preoperative planning and implant design and manufacturing. Surgeons use models to help plan surgeries but prosthetists and technologists also use models as an aid to the design and manufacturing of custom-fitting implants. These models are particularly very useful for restorative rehabilitation of oral cancer patients. Medical models are frequently used to help in the construction of Cranioplasty plates. The models are effective tools to facilitate patient education and as a teaching aid for students and ju nior colleagues. 2. Manufacture of crowns and bridges, resin models: Its use is gradually being extended to include the manufacture of temporary crowns and bridges and resin working models for loss wax casting. 3. Production of removable partial denture frameworks: The removable partial denture frameworks is made using rapid prototyping, SLA technique. It was developed by 3D Systems of Valencia, CA, USA in 1986. 4. Production of individually-customized digital aligner models for orthodontic use: Whole trays of individually-customized aligner models which serve as extremely accurate base-mold tools upon which the clear aligners are then thermoformed, can be produced by this additive technique. 5. Manufacturing of scaffolds for bioengineering and nerve guide conduits: Scaffolds for bioengineering and nerve guide conduits for peripheral nerve regeneration are the newer applications of a similar process i.e. microstereolithography ( µ SLA). Future advancements: With the improvements in the speed, reliability, and accuracy of the hardware, additive manufacturing will seriously compete with traditional manufacturing in creating end-use products. Many possible biomedical engineering applications might be available in the coming years. Conclusion: It will still be many years before the machines will be able to produce work of a quality that can be achieved by the best dental technologists in the world. For the dental materials scientist these technologies will throw up a whole new way of materials processing and with it the opportunity to use a whole new range of materials. Table-1 Basic characteristics of 3 D models (Choi et al., 2002) References and further reading: Barker, T.M, Earwaker, W.J.S, Lisle D.A. (1994) Accuracy of stereolithographic models for human anatomy.Australas Radiol,38(106). Berman, B. (2012) 3-D printing: The new industrial revolution.Business horizons,55(2), 155-162. Cassetta, M., Giansanti, M., Di Mambro, A., Stefanelli, L. V. (2013) Accuracy of Positioning of Implants Inserted Using a Mucosa-Supported Stereolithographic Surgical Guide in the Edentulous Maxilla and Mandible.The International journal of oral maxillofacial implants,29(5), 1071-1078. Choi, J.Y., Choi, J.H., Kim N.K. (2002) Analysis of errors in medical rapid prototyping models.Int J Oral Maxillofac Surg, 31(23). doi: 10.1054/ijom.2000.0135. Cunningham, L., Madsen, M., Peterson, G. (2005) Stereolithographic modeling technology applied to tumor resection.J Oral Maxillofac Surg, 63, 873–878. Gauvin, R., Chen, Y. C., Lee, J. W., Soman, P., Zorlutuna, P., Nichol, J. W., Khademhosseini, A. (2012) Microfabrication of complex porous tissue engineering scaffolds using 3D projection stereolithography.Biomaterials, 33(15), 3824-3834. Mehra, P., Miner, J., D’Innocenzo, R., Nadershah, M. (2011) Use of 3-D stereolithographic models in oral and maxillofacial surgery.Journal of maxillofacial and oral surgery,10(1), 6-13. Melchels, F. P., Feijen, J., Grijpma, D. W. (2010) A review on stereolithography and its applications in biomedical engineering.Biomaterials, 31(24), 6121-6130. Morris, L., Sokoya, M., Cunningham, L., Gal, T. J. (2013) Utility of stereolithographic models in osteocutaneous free flap reconstruction of the head and neck.Craniomaxillofacial trauma reconstruction,6(2), 87. Patel, M., Al-Momani, Z., Hodson, N., Nixon, P., Mitchell, D. (2013) Computerized tomography, stereolithography and dental implants in the rehabilitation of oral cancer patients.Dental update,40(7), 564-6. Tasaki, S., Kirihara, S., Soumura, T. (2011, November) Fabrication of Ceramic Dental Crowns by using Stereolithography and Powder Sintering Process. In Ceramic Engineering and Science Proceedings (Vol. 32(8), 141-146). American Ceramic Society, Inc., 735 Ceramic Place Westerville OH 43081 United States. Van Noort, R. (2012) The future of dental devices is digital.Dental Materials, 28(1), 3-12.

The Human Foot and Ankle Essay -- Biology, Bones, Joints

Introduction The human foot and ankle are composed of 26 bones, 33 joints, and more than a hundred muscles, tendons and ligaments. These components work together to provide the body with support, balance and mobility. The foot acts as a â€Å"rigid lever and mobile adapter† (Amstrong [Prosthetic feet], 2010). The human foot must be capable of withstanding the body’s weight and functions as a shock absorber (Swierzewski, 2007; NYU, 1990). The prosthetic foot needs to be capable of mimicking the missing natural foot, to make for the most efficient gait pattern. When due to disease, accident or developmental malformation a natural foot is absent a prosthetic foot is used to mimic the missing limb in an attempt to create the most efficient gait pattern. The prosthetist must choose from numerous types of prosthetic feet, depending upon the patient’s physical condition and life-style needs (Swierzewski, 2007). Gait Cycle The human gait cycle is comprised of multiple sequential steps. It begins with the heel of the foot contacting the ground and ends when that same foot contacts the ground again (Perry, 1992). The period of the gait cycle that the foot is on the ground is called the stance phase. The period when the foot is in the air is called the swing phase. The phases of the gait cycle are initial contact (IC), loading response (LR), mid-stance (MSt), terminal stance (TSt), pre-swing (PSw), initial swing (ISw), mid-swing (MSw) and terminal swing (TSw). There are three primary functions of the gait cycle, which are weight acceptance, single limb support, and limb advancement. Weight acceptance occurs during initial contact and loading response. During these phases, the limb is stabilized to prevent falling and the foot fun... ...activities. The main disadvantage of this foot is that it costs more than other feet, and can only be used by patients at the K3 level or above (Lusardi & Nielsen, 2007). Manufactures There are several different manufactures of prosthetic feet such as Ossur, Ottobock, Ohio Willow Wood, and SPS. Most companies specialize in adult feet though there are some manufactures such as Ossur that have a special pediatric line. On the companies’ websites, feet are organized based on K level and further categorized based upon male or female. Prosthetic feet come in different lengths in centimeters and left or right. They also are grouped by weight of the patient that can safely use the foot. Some feet come in different skin colors and others have a space between the big toe and second toe to accommodate the user who wants to wear flip-flops or shoes with toe straps.