Human Behavioral Ecology Essay Example | Topics and Well Written Essays - 1250 words

Human Behavioral Ecology - Essay Example As a result a person develops behavioral strategies to solve different problems that are set by nature like arranging for food, mating, looking after the offspring and maintaining interactions with kin, offspring and other individual. HBE gained popularity between 1960s and the 1970s when there was growing emphasis on animal behavior and evolutionary biology. J.B.S Haldane a British evolutionary biologist by 1956 had already argued that differences of human behavior could be analyzed as responses of different individuals with similar genetic composition exposed to varying environments. But the initial developments of HBE were in the field of foraging, drawn for the optimal foraging theory (OFT). This was because OFT was sophisticated and testable theory by 1980s and because much of the history of human species was spent as foragers. Foragers offer experiments for studying human behavioral variability. If people of today forage for living are constrained by aspects of ecology, then the variations in these limitations, the difficulties imposed by these constraints and the solutions that different individuals adopt to overcome the constraints are open to ethnographic observations. The OFT consists of a groups of mod els addressing resource choice, time allocation and patch choice and diet breadth model that is most commonly used in studying humans. In accordance to this model, individual foragers select food resources that promise to provide maximum nutrition, by trading off the handling and search times associated with acquiring that food source. Foragers often bypass those food sources that yield low post encounter mean rate of nutrition when more profitable food sources are common, but they take a broader array of prey species when more profitable items are rare (Kaplan and Hill, 167-201). Changes in subsistence pattern over a period time can be explained by changes in response to factors like technology, climate changes and availability of foreign imports. Thus new technology can either expand or contract the diet breadth (prey choice), depending on whether the cost of searching and handling the food resources have been affected. The diet breadth models even deals with archaeological deposi ts. For instance, deposits associated with societies that are on the brink of adopting agricultural activities, show increasing exploitation of previously unused sources, like plant food and seeds that require extensive processing. The diet breadth model as such suggests that agriculture emerged many times in history as an alternative in response to decrease in encounter rate with higher ranked nutritional items. Failures to support the foraging model predictions have been just as intriguing as the successes. For instance despite what foraging model suggest that humans acquire food that maximizes their mean acquisition, men go for large preys like animals, ignoring the small food items like plants that are more profitable for increasing their mean acquisition rate. Women on the other hand frequently do the opposite and favor small food items over large preys like animals. These observations have helped in generating two alternative hypotheses. The first hypotheses relates to the differences of constraints, that men maximize their nutritional acquisition through paying attention to the currency that gives more weightage to protein rather than

E-Business Strategy-Company Report Essay Example | Topics and Well Written Essays - 2000 words

E-Business Strategy-Company Report - Essay Example Finally, these three proposals are evaluated on the basis of advantages, risks, cost, resourcing and development timescales of each. A new concept that has emerged from the World Wide Web is of education on the web: E-learning [1], [2]. E-learning has provided students an opportunity to learn even after school hours. Through such platforms they can interact with their teachers, fellow students [3]. Saudi Arabia has launched its efforts in the field of e-learning; it is being used in several schools and universities [6], [7], [8]. The following figure shows the results of a study conducted by Al-Nuaim [11], in which students were compared on the basis of their performance when some of them were taught the same content face-to-face and some were taught online. King Abdulaziz University is named after the establisher of Saudi Arabia. It was made in 1967 with the vision of spreading quality education in the western part of the country. It is located in the city of Jeddah. A group of entrepreneurs went to King Faisal with the proposal of making a university of world class standard so that their youth can also compete with the world. King Faisal gave his full support to the idea and announced that it will be a national university. A committee was formed which was headed by King Faisal himself [4]. It has contributed to the field of e-learning to a great extent due to which Deanship of Distance Learning was established in 2004 [10]. The university has the objective to spread the knowledge of Islamic values and the highest quality of academic knowledge. They want to promote the element of innovative, superior and comprehensive research in a diverse range of fields, so that they can play their part in the development of the society. Their objective is to make their students competent professionals who possess exceptional skills [4]. The university has more than 120,000 students; there is an almost

Endangered Species Act of 1973 Assignment Example | Topics and Well Written Essays - 250 words

Endangered Species Act of 1973 - Assignment Example As it is, there are already many in society that would argue that no exceptions whatsoever should be made.   In the end, to open up an exception to private enterprises as well, no matter how well-intentioned the organization might be.   In effect, were the government to open up such exceptions to others, the floodgates would literally come alive with individuals or organizations who felt their work was so important to the public welfare that it should be permitted to continue, no matter what the cost to a given species might be.   This would go against the very intent of the Endangered Species Act, not to mention create a bureaucratic nightmare for all affected agencies as they would be charged with the task of determining who to grant an exception to, and who to deny.   At some point, it would simply not work and would be ethically improper to proceed with that course of action.  

Correlation of the light scattering properties of transparent Dissertation

Correlation of the light scattering properties of transparent conducting oxides to PV efficiency - Dissertation Example As the results show that, there is a difference between the thicknesses of the two samples, the difference between thicknesses of the two samples is due to the passes, as 236 has 18 passes and 238 has 20 passes. The more the number of passes the more will be the thickness of the surface. At 870 nm wavelength of light, the transmission remains at 79.7%, Hf (Io) is 2.5%, Hf (T) is 3.1%, Hr (Io) is 1.9%, Hr (Sp) is 40.5%, Is remains at 2.8% while absorption is 15.5%. As the wavelength decreases to 627 nm, the transmission increases to 80.3%, Hf (Io) increases to 4.6%, Hf (T) increases to 5.7%, Is increases to 9.2% while Hr (Io) decreases to 1.4%, Hr (Sp) decreases to 13.0% and absorption decreases to 9.2%. As the wavelength decreases to 530 nm, the transmission decreases to 77.9%, Is decreases to 8.3% while Hf (Io) increases to 7.1%, Hf (T) increases to 9.1%, Hr (Io) increases to 2.1%, Hr (Sp) increases to 20.0% and absorption increases to 11.7%. As the wavelength decreases to 455 nm, the transmission decreases to 74.3%, Is decreases to 5.1% while Hf (Io) increases to 13.1%, Hf (T) increases to 17.6%, Hr (Io) increases to 4.2%, Hr (Sp) increases to 45.0% and absorption increases to 16.4%.... As the wavelength decreases to 455 nm, the transmission decreases to 74.3%, Hf (Io) increases to 17.8%, Hf (T) increases to 24.0%, Hr (Io) increases to 5.7%, Hr (Sp) increases to 59.0%, absorption increases to 16.1% while Is decreases to 4.0%. And for sample 238 Wavelength Transmission Hf (Io) Hf (T) Hr (Io) Hr (Sp) Is Abs 870 82.4% 2.0% 2.4% 1.5% 11.2% 11.5% 4.6% 627 81.1% 6.3% 7.8% 2.9% 28.6% 7.3% 8.7% 530 78.0% 10.2% 13.0% 3.4% 34.8% 6.4% 12.3% 455 74.3% 17.8% 24.0% 5.7% 59.0% 4.0% 16.1% B- Transmission as a function of wavelength: For sample 238, the transmission is directly proportion to the wavelength of the projected light. As the wavelength increases, the percentage transmission increases but a rapid increase in the percentage transmission can be seen by the projection of light from wavelength of 455nm to 627nm. But for the sample 236, the percentage transmission increases in response to the light projection having wavelength from 455nm to 627nm and from 627nm to 870nm, the p ercentage transmission decreases from 80.2% to 79.8%. The little decrease in the percentage transmission provides great characteristics to indentify the material. Figure show transmission with respect to wavelength for sample 238. Figure show transmission with respect to wavelength for sample 236. C- Summery The thickness of the thin film influences the percentage transmission. As the sample 238 has less thickness as compared to the sample 236. The efficiency in terms of percentage transmission for the sample 238 is more than the sample 236. With the help of optical scattering system, which utilizes different wavelengths of light to analyze the optical properties of the thin film, it

Guru Nanak and Meera Bai Essay Example for Free

Guru Nanak and Meera Bai Essay Guru Nanak is the founder and first guru of the Sikh religion. He was born in a small town outside of Lahore, India (now Pakistan) to a family in the merchant caste. As a young man, Guru Nanak married and had children. Yet he didnt fit easily into family expectations. He seems to have only reluctantly entered the clerical profession suggested by his family, often feeling the call to turn inward in meditation at key points in his life. Guru Nanaks moment of enlightenment came when, after singing devotional songs, he bathed in the Vein River near Sultanpur. In that moment he was elevated to the heavenly state, where he received amrit, the drink of immortality in the form of the divine name. He remained in deep silence after this transcendent experience for some time, and then he started to formulate his revelation through the statement, There is neither Hindu nor Muslim suggesting the universal brotherhood we all share through the divine vision. After this awakening, Guru Nanak left his job and became a wandering holy man. He eventually settled at Kartarpur along the Ravi River, where he lived out the rest of his life. For others with the same name, see Meera (disambiguation) Meerabai (Rajasthani: ) (c. 1498-c. 1547AD) (alternate orthographies: Meera; Mira; Meera Bai) was an aristocratic Hindu mystical singer and sahajiya (apasampradaya) devotee of lord Krishna from Rajasthan and one of the most significant figures of the Sant tradition of the Vaishnava bhakti movement. Some 12-1300 prayerful songs or bhajans attributed to her are popular throughout India and have been published in several translations worldwide. In the bhakti tradition, they are in passionate praise of lord Krishna. Details of her life, which has been the subject of several films, are pieced together from her poetry and stories recounted by her community and are of debatable historical authenticity, particularly those that connect her with the later Tansen. On the other hand, the traditions that make her a disciple of Ravidas who disputed with Rupa Goswami are consonant with the usual account of her life.

Teen Pregnancy Essay Example for Free

Teen Pregnancy Essay For countless years in America teen pregnancy has been an issue for many young girls between the ages of 13 and 19 years of age. Our nation is facing an adolescent reproductive crisis, because one in three girls are becoming pregnant before the age of 20 in the United States alone. More and more teens in the United States become pregnant annually. Most if not all-teen pregnancies are unplanned and never end in abortion. Some teenagers dont plan to get pregnant, but many do. However, Teen moms often don’t have the time to focus on education, which as a result are less likely to complete high school, or enroll in community college or a four-year university. According to Teen Pregnancy Prevention 2010–2015 (2013), â€Å"As part of the Presidents Teen Pregnancy Prevention Initiative (TPPI), CDC is partnering with the federal Office of the Assistant Secretary for Health (OASH) to reduce teenage pregnancy and address disparities in teen pregnancy and birth rates. The OASH Office of Adolescent Health (OAH) is supporting public and private entities to fund medically accurate and age appropriate evidence-based or innovative program models to reduce teen pregnancy. The purpose of this program is to demonstrate the effectiveness of innovative, multicomponent, communitywide initiatives in reducing rates of teen pregnancy and births in communities with the highest rates, with a focus on reaching African American and Latino/Hispanic youth aged 15–19 years. A communitywide model is an intervention implemented in defined communities (specified geographic area) applying a common approach with different strategies. Communitywide approaches will be tailored to the specified community, and will include broad-based strategies that reach a majority of youth in the community (i. e. , through communication strategies and media campaigns); and intensive strategies reaching youth most in need of prevention programming (i. . , through implementation of evidence-based programs and improved links to services). † Pro-Choice America has long advocated for a more sensible approach to the issue of teen pregnancy programs, better access to birth control, and investing in critical after-school programs. These interventions over the next few years will reduce rates of teen pregnancy and promote more responsible behavior.

Effect Of UV Rays On Pool Chlorine Biology Essay

Effect Of UV Rays On Pool Chlorine Biology Essay Pools have always been a source of leisure for Australians. They provide enjoyment and good times for many households generated in a family or local swimming pool. Despite this, pools have to be maintained by using chemicals or disinfectants, lest unwanted pathogens create health hazards. However, the over use of these chemicals can also result in health hazards such as; serious irritation and breathing problems. A balance or equilibrium, therefore, must be achieved to maintain suitable conditions. This is where chemistry comes into play. The main type of chemicals used in pools to prevent unwanted pathogens is pool chlorine. Sodium hypochlorite is a commonly used as pool chlorine. It was discovered by Louis Pasteur in the late 19th century that sodium hypochlorite had disinfectant properties. Sodium hypochlorite effectively kills bacteria, viruses and fungi. When pool chlorine is added to water, a reaction takes place where hypochlorus acid is formed. In the past, most consumer chlorine bleach was sold in a 5.25% solution. Today, some more concentrated solutions are being sold and touted as an improvement over the less concentrated bleaches. To check for the concentration of the pool chlorine, excess potassium iodide is to be added to it and then it is to be titrated with a solution of sodium thiosulfate. The concentration of the liquid chlorine is then to be calculated using stoichiometry. The net ionic equations of the chemical reactions are: Source: Chemistry In use Book 2 There are also many factors that affect the effectiveness of pool chlorine such as sun radiation. Ultra-violet (UV) light degrades hypochlorous acid to hydrochloric acid (HCl). Ultraviolet (UV) radiation not only destroys light sensitive chemicals such as sodium hypochlorite (NaOCl), it also has the potential to significantly degrade the structural integrity of the storage tank or IBC containing the light sensitive material.   According to the NSW  Ministry of Health  (2010) roughly 1/3 of free chlorine exposed to UV lights in a outdoor swimming pool is destroyed every hour. UV light therefore lowers the concentration of the disinfection component of free chlorine. In this experiment, the concentration of sodium hypochlorite in pool chlorine, left under a UV lamps for different periods of times, was measured. Aim: To investigate the effects of Ultra Violet (UV) rays on sodium hypochlorite (a bleaching agent used commonly in pools). 2.0 Hypothesis: As pool chlorine is left for longer periods of time under UV rays, the concentration of the pool chlorine will decrease. This was hypothesised as the theory suggests that UV rays degrade the component in pool chlorine which allows it to disinfect bacteria. 3.0 Equipment/Material Material Diluted Sodium hypochlorite Sodium thiosulfate Potassium iodide Starch indicator Boiling water Equipment 2 x 100 mL Beaker 5 x 250 mL Beaker 15 x 100 mL Flask 2 x 1L Volumetric flask 1 x 500 mL Volumetric flask 1 x 100mL Measuring cylinder 2 x 20mL Measuring cylinder 3 x Funnel 5 x 20 mL Pipette 2 x 1mL Pipette 3 x Stirring rod Senior Balance Burette and stand UV Lamp Permanent marker Stopwatch 4.0 Safety To prevent any harm to the group during this experiment, safety precautions were taken to ensure the safety of the members. Refer to Appendix A for MSDS (Material Safety Data Sheet). Lots of glassware was used Refrain from holding too many pieces of glassware at once. Clean up glass immediately if any is broken. Handle boiling water with care Boiling water was used to create a solution of starch. Beaker tongs were used to carry the boiling water. Potassium iodide is irritating to eyes and skin Avoid contacting without gloves. Wash with water if contact occurs. Sodium thiosulfate is irritating to eyes and skin Avoid contacting without gloves. Wash with water if contact occurs. Starch gives skin discomfort Avoid contacting without gloves. 5.0 Procedure Refer to Appendix 1 for preparation of solutions Preparation of titration A burette and stand was filtered with the sodium thiosulfate solution. The burette was filled up with the sodium thiosulfate solution to around the 0mL mark. 100mL of diluted sodium hypochlorite was poured into 5 individual 250mL beakers. These beakers were labelled 0min, 15m, 30m, 1hr, 3hrs and 4hrs. All the beakers, except the 0min beaker, were placed under the UV lamp for the amounts of time labelled on them. At this point the stopwatch was started, once the samples had reach the specified time they were taken out. For each time sample, 20mL was measured with a pipette and placed into 3 100mL flasks. 10mL of potassium iodide solution and 2mL of starch indicator solution were prepared prior to every titration. Titration The mark of where the sodium thiosulfate solution in the burette was recorded before the titration occurred. 10mL of potassium iodide solution was added to each time sample of 20mL sodium hypochlorite solution in the 100mL flasks. The new solution was left until it has completed reacted (when the solution turns light yellow). The solution was then titrated until it turned a very pale yellow. 2mL of starch indicator solution was added to the titrating solution. This should make the solution a dark blue/black colour. Titration continued at a slower rate until the solution had turned clear. Record the finishing titre mark on the burette. These steps were repeated 3 times for each time sample (total of 18 titrations). Figure 1: Diagram of titration in progress. 6.0 Results Table 1: Table showing the amount of sodium thiosulfate solution added to sodium hypochlorite and potassium iodide solution at different times left under the UV ray. Refer to Appendix 2 for initial volume and final volume calculations and averages. Time (mins) Volume (mL) Average of 3 titrations 0 23.35 15 22.95 30 22.51 60 18.35 180 16.03 240 12.70 Table 2: Table showing the concentration of pool chlorine Refer to appendix 3 for converting of average volume of titration to concentration. Amount of time left under UV lamp (mins) Concentration of OCl (M) 0 0.03250 15 0.03198 30 0.03131 60 0.02558 180 0.02234 240 0.01770 Figure 1: Graph showing the concentrations of pool chlorine left under a UV lamp for different periods of time. 7.0 Discussion An experiment design was made to test and compare the effects of UV rays on pool environments, particularly on the impacts of chlorine concentration. In doing this, a total of 18 pool chlorine samples were put under a UV lamp for different periods of time. The concentrations of the chlorine when left untouched by UV rays were stable at around 0.03M. By exposing the pool chlorine samples to ultraviolet lights for given periods of time, the concentration of the chlorine decreased. The graph shows that as the sodium hypochlorite is more exposed to UV rays, the lower concentration of the pool chlorine was. A line of best fit was drawn to display the trend in the data. It showed that there is a linear relationship between the concentration and time left under a UV lamp. The data collected agrees with the theory that UV rays disrupt the structural integrity of the pool chlorine. The photodecomposition of chlorine is apparent as the initial levels of hypochlorite ion decreased by a signific ant amount when exposed to sunlight. The photochemical reaction that represents the situation of the experiment is: The main errors of the experiment were the inaccuracies of most aspects dealt with when implementing the experiment. One anomaly occurred when one sample of chlorine was left under the UV lamp for 60minutes. There is a major drop in concentration from 30min. This suggests that there was experimental error during the investigation. 8.0 Conclusion The results collected from this experiment suggest that the more pool chlorine is subject to UV lights, the lower the concentration of the chlorine will be. It has partially supported the hypothesis Bibliography Deb Smith, D. R. (2006). Chemistry in use Book 2. Sydney: Queensland Chemistry syllabus. Date retrieved: 05/09/12 Fletcher, D. J. (N/D). (The Sodium Hypochlorite Story). Retrieved September 5, 2012, from south shore gunite pools: http://www.southshoregunitepools.com/resources/htms/naocl.htm Gina A. Ishida, B. à ·. (N/D). IMPACT OF CHLORINE AND MONOCHLORAMINE ON ULTRAVIOLET. University of North Carolina, Chapel Hill, NC: N/A. Date retrieved: 05/09/12 N/A. (N/D, N/D N/D). Chlorination of pool water. Retrieved September 6, 2012, from pested: http://www.pested.msu.edu/resources/bulletins/pdf/2621/e2621chap7.pdf N/A. (1968). Stabiliser (Cyanurate) Use in Outdoor Swimming Pools. Retrieved September 5, 2012, from NSW Government Health: http://www.health.nsw.gov.au/utilities/copyright.asp Appendices Appendix A Going to add MSDS later†¦ Appendix 1 Diluting sodium hypochlorite 100mL of sodium hypochlorite was measured and put into a 1000mL volumetric flask. The flask was filled with distilled water up to the 1L mark The flask was inverted several times Sodium thiosulfate solution 8.82g of sodium thiosulfate was placed into a 1L volumetric flash The flask was filled with distilled water up to the 1L mark The flask was inverted several times Potassium iodide solution 5g of potassium iodide was weighed and placed into a 250mL beaker Distilled water was poured until it reached 105g on the scale The solution was thoroughly mixed Starch solution 1g of starch indicator was weighed and placed into a 250mL beaker 100mL of water was boiled and placed into the 250mL beaker The solution was thoroughly mixed and was left to cool down All solutions were labelled with the name of the solution, the concentration, a group members name and the teachers name. Appendix 2 Initial volume and final volume of sodium thiosulfate left under a UV lamp at different periods of time. 0 min 23.35-0.04 15 min 45.63-23.29 30min 22.34-0.07 = 23.31mL =22.34mL =22.27mL 46.76-23.31 23.04-0.14 44.78-22.32 = 23.45mL =22.90mL =22.46mL 23.54-0.13 46.66-23.04 23.01-0.21 =23.29mL =23.62mL =22.80mL Avg = = = =23.35mL =22.95mL =22.51mL 60 min 41.22-23.01 3 hour 15.62-1.23 4hours 13.23-0.12 =18.21mL =14.39mL =13.11mL 18.62-0.33 30.59-15.62 26.35-13.23 =18.29mL =14.97mL =13.12mL 37.26-18.72 49.32-30.59 38.21-26.35 =18.54mL =18.73mL =11.86mL Avg = = =18.35mL =16.03mL =12.70mL