ecological and environmental forces. An ecological force such as human hunters are one hypothesis that is believed to have caused the extinction of the megafauna. This hypothesis is known as the “overkill hypothesis.” (Cushman lecture 2/15/18) This hypothesis believes that the excessive practices of human hunters are what caused the large mammals of the North Americas to go extinct. An environmental force hypothesis that is also widely proposed is climate
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It affects how you feel‚ think and behave and can lead to a variety of emotional and physical problems. There is not a quick and easy way to deal with depression. From the scientific view point‚ the only way to treat depression is with medication. But in recent studies‚ the serotonin hypothesis says differently. The medication does not treat the disorder but only the symptoms. The serotonin hypothesis dates back to the 1960s. Depression is associated with a reduction in serotonin uptake sites
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BACKGROUND AND STATEMENT OF THE PROBLEM Teenage pregnancy is a common social problem in both Western and Eastern cultures. In United States‚ the statistics show that more than 3‚000 teens get pregnant every day and the half them give births (McCoullough & Scherman(1991)‚ cited in Yucel‚ 2003). Although teenage pregnancy may be considered as a positive experience‚ studies show that teenage pregnancy is associated with psychological‚ social and physical problems. The pregnancy rates reveal that
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Describe the operon hypothesis and how it explains the control of the messenger RNA production and the regulation of protein synthesis in bacterial cells. The operon is a group of genes coding for proteins with related functions and they are arranged in units. The operon is made up of the promoter‚ structural genes and the operator. Transcription depends on the regulator‚ it may be located anywhere on the bacterial chromosome. The regulator codes for the repressor‚ which binds to the operator
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CHAPTER 8 Introduction to Hypothesis Testing 8.1 Inferential Statistics and Hypothesis Testing LEARNING OBJECTIVES 8.2 Four Steps to Hypothesis Testing After reading this chapter‚ you should be able to: 8.3 Hypothesis Testing and Sampling Distributions 8.4 Making a Decision: Types of Error 8.5 Testing a Research Hypothesis: Examples Using the z Test 8.6 Research in Focus: Directional Versus Nondirectional Tests 8.7 Measuring the Size
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“Accept” the Null Hypothesis by Keith M. Bower‚ M.S. and James A. Colton‚ M.S. Reprinted with permission from the American Society for Quality When performing statistical hypothesis tests such as a one-sample t-test or the AndersonDarling test for normality‚ an investigator will either reject or fail to reject the null hypothesis‚ based upon sampled data. Frequently‚ results in Six Sigma projects contain the verbiage “accept the null hypothesis‚” which implies that the null hypothesis has been proven
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1.) Were the North American megafauna wiped out by early human colonizers? The Overkill hypothesis is of the Clovis crossing into a “virgin continent” (The America’s) and wiped out the megafauna due to overhunting. First developed by Paul Martin in the 1960’s‚ Clovis started to occupy North and South America 13‚500-12‚500 years ago; soon after early sites were established 17 genera of North and South American megafauna went extinct between 13‚250-12‚900 (other species such as ground sloths become
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HYPOTHESIS TESTING WHAT IS THIS HYPOTHESIS???? • In simple words it means a mere assumption or supposition to be proved of disproved. • But‚ for a researcher it is a formal question that he intends to resolve. • Example: I assume that 1) under stress and anxiety a person goes into depression. 2) It leads to aggressive behaviour. Eg. : Students who get better counselling in a university will show a greater increase in creativity than students who were not counselled. • So‚ the hypothesis
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Null Hypothesis (McMillan‚ 2012‚ p. 49): A null hypothesis states that no significant statistical relationship or difference exists between the groups that are being compared in astudy. This term relates to all of the studies I read for my research study analyses. They all compared the academic achievement of high school athletes and non-athletes in some way or another. While the null hypotheses were not explicitly mentioned in the studies‚ they all would have been something along the lines of
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1993‚ 1996 the oldest continent is Ur. In Rogers’ reconstructions‚ however‚ Kaapvaal and Pilbara are placed far apart already in their Gondwana configuration‚ a reconstruction contradicted by later orogenic events and incompatible with the Vaalbara hypothesis.[3]
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