If the waveform in Fig. 7.116(a) is applied to the circuit of Fig. 7.116(b), find Assume v(t). v(0) 0.
Week Thirteen Class Notes Tuesday, 19 April 2016 Drugs and Alcohol I. Drinking Patterns in the US a. 2/3 of US adults are “current drinkers” i. e.g. drink at least 1 drink during past year and 12 in lifetime 1. of those, 10% engage in binge drinking a. Binge drinking = 5 or more drinks in the same occasion at least once per month b. 15 % are “former drinkers c. 20% are lifetime abstainers II. Binge Drinking a. Most common in people ages 18-24 i. About 1/3 are binge drinkers ii. More common among males b. Levels of binge drinking drop off significantly after college III. Underage Drinking a. 35% of 15-year-olds report that they have had at least 1 drink in their lives b. Regular alcohol use during teenage years can interfere with normal adolescent brain development IV. Alcohol Consumption in the US (1790-2005) a. Difficult to access safe drinking water i. Alcohol would kill off the bacteria b. Alcohol consumption decreased as access to safer drinking water increased i. Temperance also was occurring (Starting in 1840) that reduced consumption of most substances c. Alcohol consumption peaked in mid-1800s (plentiful grain, difficult to transport) and declined around time of temperance movement. d. The declining share of youth in the U.S. population can account for 42% to 93% of the decline in per capita alcohol consumption in the 1980s. i. For example, the percentage of the population aged 18 to 29 declined 4.9 percentage points or 22% from 1978 to 2009 e. U.S. producers of distilled spirits adopted a voluntary Code of Good Practice that barred radio advertising after 1936 and television advertising after 1948. f. When this voluntary agreement ended in late 1996, cable television stations began carrying ads for distilled spirits. V. Consequences of Alcohol (Direct and Indirect Hazards) a. Cirrhosis (Direct Hazard) i. Alcohol Dehydrogenase = an enzyme contained in the liver, metabolizes alcohol 1. Metabolism of large amount of alcohol over time may be damaging ii. Cirrhosis = formation of scar tissue on the liver 1. Cirrhosis is irreversible 2. Also caused by hepatitis B and C infection 3. Increases risk for liver cancer, bleeding disorders 4. Treatment mainly includes reducing risk factors a. E.g. alcohol intake b. Fetal Alcohol Syndrome (FAS) i. Affects infants of mothers who drank heavily during pregnancy 1. Especially binge drinking ii. Can produce facial abnormalities 1. Cognitive deficiencies, ETC iii. About 5 cases per 1000 births 1. Most dangerous in second and third trimester. 2. Most research compares drinking to no drinking, making it difficult to examine safe amounts. c. Social Costs of Alcohol i. Related to aggressive behavior 1. Violent crime a. Alcohol is indicated in 2/3 of homicides ii. Also indicated in suicide attempts 1. More so than other drug use iii. Alcohol is involved in 40% of MVA fatalities 1. MVA = Motor Vehicle Accidents Benefits of Alcohol I. Evidence for a U-shaped curve between alcohol consumption and all-cause mortality a. Discussion: What does this mean exactly i. The left side of the “U” is the people who never/low rate drink alcohol = high mortality ii. The low center are the people who drink moderately = lowest mortality rate iii. Right side of is the binge drinkers = high mortality rates b. How does cigarette smoking compare i. This relationship is positively linear 1. The more you smoke, the higher the mortality c. http://www.reuters.com/article/us-health-drinking-idUSKCN0WO2DX d. “Most of the studies compared moderate drinkers – people who had one or two drinks a day – with current abstainers. The problem is the studies didn’t account for medical reasons that may have driven abstainers to avoid alcohol, potentially exaggerating the health benefits seen with moderate drinking. e. After taking this so-called abstainer bias into account, “our study found no net benefits overall,” f. The analysis didn’t look at whether certain types of alcohol such as red wine might be tied to longer life, the authors note. It also focused on mortality from all causes, which means it’s still possible that drinking might be associated with a longer life for people with certain conditions such as heart disease, Stockwell said.” II. CVD a. Light to moderate drinking associates with lower CVD risk i. Moderate = 1. 1/day for women 2. 2/day for men ii. Light = 1. <1 /day, but not an “abstainer” iii. Abstainers and heavy drinkers had highest mortality b. Reduces atherosclerosis III. BUT à NOT ALWAYS GOOD a. Alcohol consumption is linked to breast cancer risk i. No increased risk 1/day ii. But greater risk for each drink after that b. All alcohol is not created equal i. Wine has greater health benefits than beer or hard liquor c. A daily intake of one glass of wine or beer -- or less -- would correspond to a risk value of 1. However, if we increase our intake to two daily glasses of wine or beer, our risk would rise by 4 percent." Screening for Alcohol and Drug Abuse I. CAGE a. Who would use these forms i. Rehab centers ii. In-take forms at hospitals b. Used to screen for potential alcohol and drug problems in medical settings c. Positive screen requires follow-up and additional screening i. 1 or more items “yes” Treatment for Problem Drinking II. Alcoholics Anonymous (AA) a. Most widely used alcohol treatment program b. Requires total abstinence, follows disease model of alcoholism i. Not all treatment models require this c. No experimental studies, little evidence of effectiveness d. May work for some people by providing peer support i. Low cost and widely found III. Controlled Drinking a. Movement started in late 1960s after study found that some patients were able to reduce problematic drinking to moderate levels and maintain this for years b. Tells you that you currently have a problem, but dropping down in consumption will not cause total relapse ii. Should the goal be total abstinence or controlled drinking 1. Depends on how you conceptualize problem drinking a. AA considers all levels to be a problem once you are in the program b. Controlled Drinking allows consumption given they are living a normal, productive life IV. Motivational Interviewing for Problem Drinking a. Can be used as brief intervention to help client explore their ambivalence regarding change b. Good tool for those who may not view drinking as a problem Marijuana I. Marijuana and Cannabinoids a. Cannabinoids – groups of compounds produced by cannabis species i. Delta-9-tetrahydrocannabinol (THC) = primary psychoactive ingredient ii. Cannabidiol (CBD) = analgesic and anti-inflammatory properties 1. Without the psychoactive effects of THC II. Marijuana Use in the US a. Second most widely smoked substance after tobacco b. 36.4% of high school seniors in the US reported using marijuana within the past year III. Is Marijuana Addictive a. It can be i. But not as much as alcohol or prescription opioids ii. Research shows similar disruption in dopamine processing among heavy marijuana users as those addicted to opioids and stimulants 1. E.g lower capacity to experience pleasure b. Some evidence of tolerance, withdrawal, and dependence among a small group of heavy, long-term users. i. The more often you use marijuana the more likely you are to become dependent. IV. Reward Deficiency Syndrome a. What is it i. A disruption in the reward system 1. Typically characterized by too few dopamine receptors a. Especially D2 receptors 2. Muted response to life’s pleasures 3. These people are more likely to suffer from addiction to a. Marijuana b. Alcohol c. Cigarettes d. Among other drugs b. Not specific to Marijuana use i. Happens with use of all drugs V. Marijuana and Symptom Management a. Studies have demonstrated beneficial effects in cancer populations from synthetically derived cannabinoids (EX: Marinol) i. Anti-nausea ii. Appetite stimulation iii. Analgesic effects VI. Marijuana and Cancer Risk a. Toxins and carcinogens are released from the combustion of materials i. Whether it be marijuana or tobacco 1. E.G. tar components like benzopyrene are similar to what is found in tobacco smoke b. Marijuana smoke contains carcinogens i. However, epidiological findings ate largely inconclusive for cancer risk 1. Why is this a. There are no huge longitudinal studies yet b. Cigarette smokers smoke extremely frequently i. Typically marijuana smokers smoke a lower volume than cigarette smokers 2. Best longitudinal study to date: 3. (n = 49,321) 18–20 years old 4. Heavy use (> 50 times) at baseline more than a twofold risk (hazard ratio 2.12) over the 40-year follow-up of developing lung cancer. 5. Controlled for baseline tobacco use, alcohol use, respiratory conditions, and SES. c. Marijuana use patterns are different from cigarette use patterns i. Marijuana smokers breathe more deeply and hold breathe longer than cigarette smokers ii. Marijuana smokers smoke less (avg. 1-3 joints/day) compared to cigarette smokes (avg. 20 cigs/day) VII. Marijuana and Cognitive Effects a. Some cross-sectional and longitudinal data suggest heavy marijuana use may be associated with long-term cognitive effects i. E.g 1. Poorer memories 2. Lowered attention processing speed ii. These studies have difficulty establishing causality though iii. Effects seem to be stronger for those who have heavy use and start at young age 1. When brain is still developing b. High level smoking Thursday, 21 April 2016 Eating and Weight I. MI (Body Mass Index) a. NOT A PERFECT MEASURE! b. BMI = kg/m^2 i. Weight in kilograms divided by height in meters squared c. BMI 25-29.9: Overweight d. BMI greater than or equal to 30: Obese e. BMI does not make distinction between i. Visceral fat vs. Subcutaneous 1. Visceral = Lies deep within abdominal cavity a. Can be harder, not soft like subcutaneous 2. Subcutaneous = lies closer to skin surface ii. Muscle vs. Fat 1. Bone and muscle weigh more than fat 2. Athletes may have high BMI II. Waist- to- Hip Ratio a. Assesses fat distribution, not just height and weight like the BMI i. Weight carried around waist is most concerning from a health perspective 1. Poorer health = high waist-to hip ratio Gender Excellent Good Average At Risk Male <0.85 0.85- 0.90-0.95 0.95+ 0.89 Female <0.75 0.75- 0.80-0.85 0.86+ 0.79 III. Obesity in the US a. Percent of adults age 20+ who are obese = 34% (as of 2011-12) b. Percent of adults age 20 and over who are overweight, including obesity = 69% (as of 2011-12) What Does a Healthy Diet Look Like I. The ‘Food Plate’ controversy a. Out with the food pyramid, in with the food plate b. USDA released ‘food plate’ in 2011 that was not without controversy i. Harvard followed with their own food plate, which they described as “based exclusively on the best available science and was not subjected to political or commercial pressures from food industry lobbyists” II. Change in School Lunch Programs a. School lunches are not known for providing science-based healthy food b. This is starting to change in some places c. Video i. Pilot Program in San Francisco “The Future Dinning Experience” 1. Aim to make better choices for the students a. Creating a lounge type atmosphere for the kids b. Serve food in hallways in mobile cart to cut lines at lunch to make sure the kids get to eat during lunch period c. Problem i. Requires money and resources to make possible III. Trends Contributing to Obesity a. Increased portion sizes i. Restaurants and products advertise larger sizes 1. Ex: Double Gulp, Supersize 2. Average hamburger size: a. 1955: 2.9 ounces b. 2006: 12 ounces 3. Average man’s weight: a. 1955: 166lbs b. 2006: 194lbs 4. Calorie intake a. Average Pizza Slice i. 1955: 500 ii. 2006: 850 ii. Plate Size has increased to accommodate larger portions iii. One study looked at the date of introduction of “larger-sized” products over the past 40 years b. Increase in Fast Food Consumption i. Americans get about 12% of their daily calories from fast food ii. Fast food consumption in the US differs by: 1. Age a. Younger people (age 20-39) are intaking more % of calories fro fast food 2. SES a. Accessibility to grocery stores effects these decisions 3. Ethnicity a. Black people are also taking in more calories from fast food c. Increase in processed foods and sugar sweetened sodas i. Added sugars and sweeteners 1. USDA recommends that the average person on a 2,000- calorie daily diet consume <40grams of added sugars a. That’s about 10 teaspoons, or the amount of sugar in a 12-ounce soft drink 2. How many tsp do Americans consume per day a. 32 tsp b. Pound per capita of sugar consumption 1950 and 2000 1950-1959 2000-2009 Total Sweeteners 109 152 (in lbs) Cane and beet 97 66 sugar Corn sweeteners 11 85 Other 2 2 c. Is sugar addictive i. Some research 9mainly in animal models) has found that sugar can have dopaminergic and opioid effects that are similar to psychostimulant and opiate drugs ii. Sugar triggers activation of dopamine in the nucleus accumbens and release of endogenous opioids 1. Nucleus Accumbens = reward center 2. Endogenous Opioids = Withdrawal symptoms triggered after removal of sugar iii. Delivering opioid antagonist reduces consumption of sugar in mice d. Reduction in physical activity and increase in sedentary behavior i. EX: television watching ii. Television viewing has dramatically increased since the 1950s iii. According to Nielsen Research 1. The average American watches 4-5 hours of tv each day a. 2 months of nonstop tv watching per year 2. In 65 year life, that person will have spent 9 years glued to the television Bold Book Vocabulary: Chapter Fourteen: Eating and Weight 1. Amenorrhea – Cessation of the menses 2. Anemia – A low level of red blood cells, leading to generalized weakness and lack of vitality 3. Anorexia Nervosa – An eating disorder characterized by intentional starvation, distorted body image, excessive amount of energy, and an intense fear of gaining weight 4. Anus – Opening through which feces are eliminated 5. Bile Salts – Salts produced in the liver and stored in the gall bladder that aid in digestion of fats. 6. Body Mass Index (BMI) – An estimate of obesity determined by body weight and height 7. Bulimia – An eating disorder characterized by periodic binging and purging, the latter usually taking the form of self-induced vomiting or laxative abuse 8. Cholecystokinin (CCK) – A peptide hormone released by the intestines that may be involved in feelings of satiation after eating 9. Eating Disorder – Any serious and habitual disturbance in eating behavior that produces unhealthy consequences. 10.Electrolyte Imbalance – A condition caused by loss of body minerals 11.Esophagus – The tube leading from the pharynx to the stomach 12.Feces – Any material left over after digestion 13.Gall Bladder – A sac on the liver in which bile is stored 14.Gastric Juices – Stomach secretions that aid in digestion 15.Ghrelin – A peptide hormone produced primarily in the stomach, the level of which rise before and after meals 16.Hypoglycemia – Deficiency of sugar in the blood 17.Hypothalamus – A small structure beneath the thalamus, involved in the control of eating, drinking, and emotional behavior. 18.Leptin – A protein hormone produced by fat cells in the body that is related to eating and weight control 19.Liver – The largest gland in the body; it aids in digestion by producing bile, regulates organic compounds of the blood, and acts as a detoxifier of blood. 20.Pancreatic Juices – Acid-reducing enzymes secreted by the pancreas into the small intestines 21.Peristalsis –Contractions that propel food through the digestive tract 22.Pharynx – Part of the digestive tract between the mouth and the esophagus 23.Rectum – The end of the digestive tract leading to the anus 24.Salivary glands – Glands that furnish moisture that helps in tasting and digesting food. 25.Setpoint – A hypothetical ratio of fat to lean tissue at whish a person’s weight will tend to stabilize 26.Thalamus – Structure in the forebrain that acts as a relay center for incoming sensory information and outgoing motor information