Transcript Pres_winter_17_Omnivore

Sustainability
Winter 2009
Class 17
Jeff Fletcher
Logistics
• 1 on 1 meetings today
– If missed last time, be sure to see me after
class to reschedule
• Reminders for next time:
– Read Omnivore’s Dilemma Ch. 8 and 9
– HW 5 due next class
– Guest Speaker: Tom Ricciardi
Discussion on King Corn
• What did you learn?
• Most memorable facts?
• Does it change the way you look at your
food?
• How much of your spending goes towards
food?
– Groceries vs. eating out?
• Earl Butz effort to end hunger vs.
“Subsidizing Happy Meals not Healthy
Meals”
Corn and Corporations
• Cargill and ADM buy 1/3 of corn in
America
• 3/5 of grown corn goes to feed animals in
factory farms
• “Industrial thinking over logic of evolution”
• 4 companies butcher 4/5 cows in America
Diseases From Food
• Besides diseases of overconsumption and bad
diets
• Most common foodborne infections (from CDC)
– Bacteria: Campylobacter, Salmonella, and E. coli
O157:H7
– Viruses: Norwalk and Norwalk-like viruses.
– Occasionally foodborne, infections by Shigella,
hepatitis A, and the parasites Giardia lamblia,
Cryptosporidia, tapeworms.
• Foodborne toxins
– pesticides, herbicides
– Natural toxins:
• Bacteria grow on food: Staphylococcus aureus, Clostridium
botulinum. Harmful even after cooking and bacteria have
been killed
• Other: poisonous mushrooms; poisonous reef fish
• Fungi that grow on foods, e.g. peanuts
Biological Reproduction Differences
• Basic Transcription and Translation of DNA into
Protein
• Bacteria
– Most scientists consider this LIFE: a living organism
• Viruses
– Some scientist consider this LIFE, many don’t
• Multi-cell parasites
– Giardia
– Tapeworms
New Form of Disease Causing
Agent
• Protein Structure (e.g. Hemoglobin)
• Prions (proteinaceous infectious particles)
• Stanley Prusiner first coined the word and first proposed
that these infectious proteins were the cause of the
disease scrapie in sheep and more importantly
Creutzfeldt-Jakob disease in humans.
• Prusiner also proposed that the way that this protein
multiplied was not though genetic information like DNA
or RNA, but rather through the conformation change of
normal proteins into rogue proteins.
• Affects nerve cells in mammals
– Cannot Kill
– Not neutralized by digestion, cooking, even normal autoclaving
– Kills nerve cells, but slow process
Consequences of Cheap Corn
Policies?
• In groups construct a causal diagram
– Include as many details as you have time for
• Both positive and negative effects
• Capture as many of the intermediary steps as possible
• Example: Cows eating corn
– What are upstream causes?
• Farmers get paid more the more they grow, more corn on market
drives down price, cattle raisers go for cheapest calories.
• More subtle: USDA grades corn fed beef higher
– What are down stream consequences?
• Cows get sick (bloat, acidosis), need antibiotics, increased
resistance, increased human disease, need for more expensive
antibiotics
• More subtle: acid environment causes E. coli and other bacteria to
evolve to be acid resistant, so if humans eat these bacteria are not
killed, leads to more human infections