The article “Brain Shunt Tested to Treat Alzheimer’s” (San Francisco Chronicle, October 23, 2002) summarizes the findings of a study that appeared in the journal Neurology. Doctors at Stanford Medical Center were interested in determining whether a new surgical approach to treating Alzheimer’s disease results in improved memory functioning. The surgical procedure involves implanting a thin tube, called a shunt, which is designed to drain toxins from the fluid-filled space that cushions the brain. Eleven patients had shunts implanted and were followed for a year, receiving quarterly tests of memory
- a. What were the researchers trying to learn? What questions motivated their research?
- b. Do you think that the study was conducted in a reasonable way? What additional information would you want in order to evaluate this study?
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Chapter 1 Solutions
Introduction To Statistics And Data Analysis
- Neurologists have found that the hippocampus, a structure located in the brain, plays an important role in short-term memory. Data was collected on 21 Vietnam veterans with combat related post-traumatic stress disorder. Magnetic resonance imaging was used to measure the volume of the right hippocampus (in cubic millimeters) of each subject, while the verbal memory retention of each subject was measured by the percent retention subscale of the Wechsler Memory Scale. The least squares line relating verbal memory (y) with right hippocampal volume (x) was found to be 4 + 3x. The slope of the regression line can be interpreted in the following way: ŷ = When right hippocampal volume decreases by one cubic millimeter, the verbal memory score increases by 3%. When right hippocampal volume decreases by one cubic millimeter, the verbal memory score increases by 4%. When right hippocampal volume increases by one cubic millime decreases by 3%. the verbal memory score When right hippocampal volume…arrow_forwardPatients immobilized for a substantial amount of time can develop deep vein thrombosis (DVT), a blood clot in a leg or pelvis vein. DVT can have serious adverse health effects and can be difficult to diagnose. On its website, drug manufacturer Pfizer reports the outcome of a study looking at the effectiveness of the drug Fragmin (dalteparin) in preventing DVT in immobilized patients. Of the 1518 randomly chosen immobilized patients given Fragmin, 42 experienced a complication from DVT. Of the 1473 randomly chosen immobilized patients given a placebo, 73 experienced a complication from DVT. Compute the proportion (risk) of patients experiencing DVT complications for immobilized patients treated with Fragmin. (Enter the proportion with 4 decimal places. DO NOT enter the percent.)arrow_forwardAppalachian Bear Rescue (ABR) is a not-for-profit organization located near the Great Smoky Mountains National Park. ABR's programs include the rehabilitation of orphaned and injured black bears, as well as research and education about Appalachian black bears. ABR provides the most natural environment possible for rehabilitating black bears before their release back into the wild. Recently, Katie Settlage performed a study to learn more about the Appalachian black bear population in the Great Smoky Mountains National Park. She and a team of researchers found 68 black bears in the park and took measurements such as paw size, weight, and shoulder height. The stem-and-leaf plots below show the shoulder heights (in centimeters) of the 40 male and 28 female bears from the study. Shoulder Heights (in cm) of Male Bears Shoulder Heights (in cm) of Female Bears 4 9 Key: 4 9 = 49 Key: 5|0 = 50 5 7 8 9 71 1 2 2 2 2 2 3 3 3 4 4 5 5 6 6 788 8 123 4 4 5 6 79 90 0 3 6 79 7 8 1 2 3 3 3 33 4 6 7 555 5…arrow_forward
- Measles is a highly contagious infection of the respiratory system and is caused by a virus. Despite the fact that more than 80% of the world’s population is vaccinated for it, measles remains the fifth leading cause of death worldwide. In general, the term pathogenesis refers to the way a disease originates and develops over time. In the case of measles, the virus enters through the respiratory tract and replicates there before spreading into the bloodstream and then the skin.The measles pathogenesis function used to model the development of the disease is given by the following equation: f (t) = −t (t − 21) (t + 1) Where t is measured in days and f (t) represents the number of infected cells per millilitre [mL] of plasma. What is the peak infection time for the measles virus? Solve the above problem through the following steps: (a)Expand equation f (t) = −t (t − 21) (t + 1) in fully. (b) Calculate the first derivative f′ (t), of the equation found in part (a). (c) Find the…arrow_forwardDo Left-Handers Die Earlier? According to a study published in the Journal of the American Public Health Association, lefthanded people do not die at an earlier age than right-handed people, contrary to the conclusion of a highly publicized report done 2 years earlier. The investigation involved a 6-year study of 3800 people in East Boston older than age 65. Researchers at Harvard University and the National Institute of Aging found that the “lefties” and “righties” died at exactly the same rate. “There was no difference, period,” said Dr. J. Guralnik, an epidemiologist at the institute and one of the coauthors of the report.arrow_forwardMeasles is a highly contagious infection of the respiratory system and is caused by a virus. Despite the fact that more than 80% of the world’s population is vaccinated for it, measles remains the fifth leading cause of death worldwide. In general, the term pathogenesis refers to the way a disease originates and develops over time. In the case of measles, the virus enters through the respiratory tract and replicates there before spreading into the bloodstream and then the skin.Figure 1: Shown is a transmission electron micrograph of a measles virus.1The measles pathogenesis function used to model the development of the disease is given by the following equation: f (t) = −t(t − 21)(t + 1) (2)where t is measured in days and f (t) represents the number of infected cells per milliliter [mL] of plasma. What is the peak infection time for the measles virus? Solve the above problem through the following steps:(a) Expand equation 2 fully. [1] (b) Calculate the first derivative f′ (t), of the…arrow_forward
- Measles is a highly contagious infection of the respiratory system and is caused by a virus. Despite the fact that more than 80% of the world’s population is vaccinated for it, measles remains the fifth leading cause of death worldwide. In general, the term pathogenesis refers to the way a disease originates and develops over time. In the case of measles, the virus enters through the respiratory tract and replicates there before spreading into the bloodstream and then the skin. Figure 1: Shown is a transmission electron micrograph of a measles virus. The measles pathogenesis function used to model the development of the disease is given by the following equation: f (t) = −t (t − 21) (t + 1) Where t is measured in days and f (t) represents the number of infected cells per millilitre [mL] of plasma. What is the peak infection time for the measles virus? Solve the above problem through the following steps: (a) Expand equation 2 fully. (b) Calculate the first derivative f′ (t), of the…arrow_forwardA biochemist is testing the effect of a new antibiotic on a particulararrow_forwardDairy cattle are cattle that are bred for their ability to produce large quantities of milk. Lameness is a condition that can be detrimental to cattle since it can be painful and result in deleterious effects on the animal’s welfare. It is a condition in which cows have difficulty moving and especially walking. Investigators are interested in whether milk production in dairy cows is associated with whether or not the cow becomes lame. They think that the age of the cow (young or old) may confound and/or modify the relationship between milk production and lameness and so they collect information on the age of the cows as well. The data that cross classifies lame status and milk production status is stratified by age and provided in the tables below. Use SAS to complete each part. (a) Ignoring age, report the estimate for the OR and its corresponding 95% confidence interval. Interpret both. (b) Ignoring age, is milk production associated with lameness? Justify your response using a…arrow_forward
- In August and September 2005, Hurricanes Katrina and Rita caused extraordinary flooding in New Orleans, Louisiana. Many homes were severely damaged or destroyed; of those that survived, many required extensive cleaning. It was thought that cleaning flood-damaged homes might present a health hazard due to the large amounts of mold present in many of the homes. The article “Health Effects of Exposure to Water-Damaged New Orleans Homes Six Months After Hurricanes Katrina and Rita” (K. Cummings, J. Cox-Ganser, et al., American Journal of Public Health, 2008:869–875) reports that in a sample of 365 residents of Orleans Parish who had participated in the cleaning of one or more homes, 77 had experienced symptoms of wheezing, and in a sample of 179 residents who had not participated in cleaning, 23 reported wheezing symptoms (numbers read from a graph). Can you conclude that the frequency of wheezing symptoms is greater among those residents who participated in the cleaning of flood-damaged…arrow_forwardA researcher hypothesized that children's cholesterol levels may be affected by educating their parents on proper nutrition and exercise. A random sample of 40 families with a child between the ages of 10 to 15 who had been diagnosed with high cholesterol were recruited to participate in the study. All parents were provided with educational information on nutrition and exercise. After following the prescribed program, the child's total cholesterol was measured. The children's (the sample) mean cholesterol level was 185 with a standard deviation of 19.5. Is there significant evidence of that their cholesterol level after this intervention is lower than the population mean of 191?arrow_forwardCalcium is the most abundant mineral in the human body and has several important functions. Most of the body calcium is stored in the bones and teeth, where it functions to support their structure. Recommendations for calcium are provided in Dietary Reference Intakes, developed by the Institute of Medicine of the National Academy of Sciences. The recommended adequate intake (RAI) for calcium for adults (ages 19-50) is 1000 mg per day. A random sample of 18 adults with incomes below the poverty level gave the following calcium intakes:886 633 943 847 934 8411193 820 774 834 1050 10581192 975 1313 872 1079 809Assume the population standard deviation for daily calcium intake for adults with incomes below the poverty level is 188mg.At the 0.05 level of significance, does the data provided above provide evidence to suggest that the mean calcium intake of all adults with incomes below the poverty level is less than the RAI pf 1000mg per day? Step 1: Define the parameter & setup the…arrow_forward
- Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage Learning