PR 680 Lecture Notes - Lecture 59: Traumatic Brain Injury

11 views3 pages

periwinklemammoth360

23 Mar 2020

School

Ball State University

Department

Public Relations

Course

PR 680

Professor

Dr. Sungwon Chung

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

There are three types to an experimental design: independent measures/between groups: This basically means that you use different participants in each condition of whatever your independent variable is. It avoids fatigue from people participating because they only have to participate in a single condition. You need more people than you would a design that repeats participants use in the study. The differences of the people participating could alter results: repeated measures/within groups: This is when the same participants are used in each condition of your independent variable. There is a reduction of the variables between participants because the same people are used. You don"t need as many people because the same participants are used in all conditions. There could be order effects like fatigue or bias because some participants might know what to do in a certain condition because they"ve practiced it before: matched pairs:

Related Questions

You and your hypothetical lab partner each develop an experimental plan to test this hypothesis. The two experimental plans are presented below. Evaluate each plan for its pros and cons in the experimental design using the bullet points below. Both experimental plans have some good elements and areas that could be improved.

Experiment A) Mature 2 inch sections (sprigs) of Elodea will be used to measure oxygen production under different light conditions. 5 sprigs will be tested. One will be kept in the dark (no light). The others will be exposed to a light filtered with cellophane. One sprigâs light will be filtered through clear cellophane to receive all wavelengths of light, and the other sprigsâ light will be filtered through red, blue, and green cellophane, respectively. The no-light plant will be kept in a dark cabinet, while the other plants will be together on a counter. Each plant sprig will be placed in equal sized upside-down test tubes in 100ml of tap water so that oxygen bubbles produced by the plant will be trapped at the top of the test tube. A ruler will be used to measure the length of the oxygen pocket collected at the top of the test tube. The experiment will continue until one sprig produces 5 cm of oxygen in the tube.

Experiment B) 3 cm sections (sprigs) of Elodea of various ages will be used to measure oxygen production under different light conditions. 15 sprigs will be divided into 3 groups of 5 sprigs each. One group will receive natural sunlight, one group will be exposed to a blue light bulb under a box to block natural light, and the final group will be exposed to a red light bulb under a similar box to block natural light. Each group of plant sprigs will be trapped under a clear plastic funnel that is covered by an upside-down test tube to collect oxygen bubbles produced by all the sprigs in the group. All groups will be in 100ml of water of the same temperature and pH. The experiment will continue for 24 hours, and then the volume of oxygen gas produced will be measured by multiplying the length of the oxygen pocket by the circle described by the test tube, ?r². The average volume produced by all groups will be graphed and compared to determine which condition produced the most total volume of oxygen.

Consider the following questions to evaluate experimental plans A and B (DO NOT ANSWER THESE QESTIONS)

What is the independent variable suggested by the hypothesis? Do both plans test the independent variable equally well?

What is the dependent variable in each experiment? Which experimentâs dependent variable best matches the prediction in the hypothesis?

What are the experimental and control groups for each experiment? Which experiment gives the best opportunity to assess the effect of the independent variable?

How does each experiment account for standardized variables? Which experiment do you think is the better controlled experiment?

How is sample size addressed in each experiment? Which would you find to be more convincing?

Does either experiment describe any statistical analyses to be performed on the data?

ANSWER THIS QUESTION: BELOW

Considering your analysis of each of the questions above,write an improved experimental design to test the hypothesis âIf blue light is more effective at promoting photosynthesis, then more oxygen gas (O₂) will be produced when plants are exposed to blue-filtered light compared to other wavelengths.âYou may use elements of the above experiments

lilaccod491

1. The risk of acquiring disease is measured by the

a. Incidence rate

b. Incidence rate times the average duration of the disease

c. Incidence rate divided by the prevalence rate

d. Prevalence rate

e. Prevalence rate times the average duration of the disease

2. The strength of an association between a factor and a disease is best measure by .

a. Incubation rate

b. Incidence of the disease in the total population

c. Prevalence of the factor

d. Attributable risk

e. Relative risk

3. Case fatality rate for a given disease refers to

a. The crude mortality rate per 100,000 population

b. Cause-specific mortality rate due to the disease

c. A fatal outcome of any disease

d. The percentage of deaths among cases of the disease

e. The proportion of deaths due to the disease among all deaths from all causes

4. An investigator is interested in etiology of neonatal jaundice. To study this condition, he selected 100 children who were diagnosed with this condition and 100 children born in the same period and in the same hospital who did not have a diagnosis of neonatal jaundice. He then reviewed the obstetrical and delivery records of their mothers to determine various prenatal and perinatal exposures. This is an example of a(n):

a. Cross-sectional study

b. Case-control study

c. Cohort study

d. Clinical trial

e. Experiment

5. Which of the following statements describes the major advantages of a randomized clinical trial?

a. It avoids observer bias

b. It lends itself to ethical justification

c. It yields results replicable in other patients

d. It rules out self-selection of participants to the different treatment groups

d. It enrolls representative patients

a. Correct b.

Incorrect because of failure to distinguish between incidence and prevalence

c. Incorrect because a proportionate ratio is used when a rate is required to support the inference

d. Incorrect because a failure to recognize a possible cohort phenomenon

e. Incorrect because there is no control or comparison group.

7. An investigator determines the correlation coefficient between triglyceride levels and degree of atherosclerosis in sampled blood vessels to be +1.67. On the basis of this you would conclude that:

a. Triglyceride level is a good predictor of atherosclerosis

b. Triglyceride level is not a good predictor of atherosclerosis

c. High triglyceride levels cause atherosclerosis

d. Atherosclerosis cause high triglyceride levels

e. The investigator has incorrectly determined the correlation coefficient

a. The percent of all negative tests that have false-negative results is lower in population A than in population B.

b. Specificity is lower in population A than in population B.

c. Reliability is higher in population A than in population B.

d. The percent of all positive tests that have false-positive results is lower in population A than in population B.

e. Specificity is higher in population A than in population B.

9. Serum cholesterol levels are obtained for four healthy men. The probability that all will fall below the 10th percentile of the distribution of cholesterol for healthy males is:

a. 0.4

b. 1 â (0.1)4

c. (0.1)4

d. (0.9)4

e. Cannot be determined from these data

10. In a diabetes screening program, the screening level for a positive blood sugar level in test 1 is set at 160 mg/dl, and in test 2 at 130 mg/dl. The sensitivity is:

a. Greater in test 1

b. Greater in test 2

c. Equal in test 1 and 2

d. Dependent on the size of the population being evaluated

1. The risk of acquiring disease is measured by the a. Incidence rate b. Incidence rate times the average duration of the disease c. Incidence rate divided by the prevalence rate d. Prevalence rate e. Prevalence rate times the average duration of the disease

2. The strength of an association between a factor and a disease is best measure by a. Incubation rate b. Incidence of the disease in the total population c. Prevalence of the factor d. Attributable risk e. Relative risk

3. Case fatality rate for a given disease refers to a. The crude mortality rate per 100,000 population b. Cause-specific mortality rate due to the disease c. A fatal outcome of any disease d. The percentage of deaths among cases of the disease e. The proportion of deaths due to the disease among all deaths from all causes

5. Which of the following statements describes the major advantages of a randomized clinical trial? a. It avoids observer bias b. It lends itself to ethical justification c. It yields results replicable in other patients d. It rules out self-selection of participants to the different treatment groups d. It enrolls representative patients

6. A survey conducted in England revealed that of 224 families in which there had been a known case of poliomyelitis, 56 maintained parakeets as a family pet. In another British survey, 30 out of 99 poliomyelitis patients questioned kept parakeets. The inference that there is some relationship between the presence of a parakeet in a household and the occurrence of poliomyelitis among household members is a. Correct b. Incorrect because of failure to distinguish between incidence and prevalence c. Incorrect because a proportionate ratio is used when a rate is required to support the inference d. Incorrect because a failure to recognize a possible cohort phenomenon e. Incorrect because there is no control or comparison group.

7. An investigator determines the correlation coefficient between triglyceride levels and degree of atherosclerosis in sampled blood vessels to be +1.67. On the basis of this you would conclude that: a. Triglyceride level is a good predictor of atherosclerosis b. Triglyceride level is not a good predictor of atherosclerosis c. High triglyceride levels cause atherosclerosis d. Atherosclerosis cause high triglyceride levels e. The investigator has incorrectly determined the correlation coefficient

8. A screening test of known sensitivity and specificity is applied to two populations. The prevalence of the disease being screened for is 10% in population A and is 1% in population B. Which of the following is true? a. The percent of all negative tests that have false-negative results is lower in population A than in population B. b. Specificity is lower in population A than in population B. c. Reliability is higher in population A than in population B. d. The percent of all positive tests that have false-positive results is lower in population A than in population B. e. Specificity is higher in population A than in population B.

9. Serum cholesterol levels are obtained for four healthy men. The probability that all will fall below the 10th percentile of the distribution of cholesterol for healthy males is: a. 0.4 b. 1 â (0.1)4 c. (0.1)4 d. (0.9)4 e. Cannot be determined from these data

10. In a diabetes screening program, the screening level for a positive blood sugar level in test 1 is set at 160 mg/dl, and in test 2 at 130 mg/dl. The sensitivity is: a. Greater in test 1 b. Greater in test 2 c. Equal in test 1 and 2 d. Dependent on the size of the population being evaluated

Part II 1.The California Occupational Mortality study data set was employed to assess mortality data for the years 1979-1981. A 2% sample of employed persons from the 1980 census of California was used. It contains the occupation of each person who had died. This study, like any occupation-based study, is restricted to the work life span as far as age of subjects is concerned. This study used ages 16-64 years. Certain persons, because of their source of work, were excluded as subjects: homemakers, retired persons, students, disabled, military personnel, etc. Only main-stream-type employment was used in this study to establish occupations at risk for heavy alcohol drinking. Using the Table below, answer the following:

1.What occupations are most vulnerable to acquiring cirrhosis of the liver from heavy drinking?

2.List several of the occupations identified by the research studies that are more vulnerable to alcohol-induced, cirrhosis related deaths and that have the highest mortality rates.

3. What are possible confounding variables for the research in occupations and heavy drinking that lead to fatal diseases?

4. Based on available research data, develop and construct a web of causation along with the appropriate decision trees for occupational group-related alcohol deaths. Table. Alcohol Related Deaths in California, 1979-1981 Cirrhosis 5.5% Digestive organ cancers 5.7% Injuries 13.7% Suicide and homicide 5.% All other causes 64.9%

Zika and microcephaly Since May 2015, Brazil has experienced a significant outbreak of Zika virus. In recent years, Brazilian officials reported an increase in the number of babies born with microcephaly.

1. Briefly describe what we know and what we do not know about Zika virus.

2. What has been done and what should be done to prevent Zika virus epidemic in US and world-wide?

PR 680 Lecture Notes - Lecture 59: Traumatic Brain Injury

Document Summary

Get access

Related Documents

PR 680 Chapter Notes - Chapter 9: Longitudinal Study, Unknown Caller, Likert Scale

PR 680 Chapter Notes - Chapter 10: Artificiality, Multivariate Analysis, Internal Validity

PR 680 Lecture Notes - Lecture 57: Statistical Unit, Sleep Deprivation

Related Questions