Title: Extra Slides
1Extra Slides
2Scientific Models and Inquiry
- Models of atoms, periodic table, bonding, shape
- Inquiry
- Hot and cold packs
- Well Wishes case study
3Scientific Inquiry Model
Is it accurate? Is it sufficient have you done
anything that is not found in the model? What is
missing?
4Model 2 Simplest
From http//acept.la.asu.edu/courses/phs110/si/c
hapter1/main.html
5Model 3 Table
Goal the objective of doing the study
Model any and all abstractions of what is being studied or manipulated
Data observations made to represent "nature"
Evaluation comparing the model to the data, to decide if the model is okay
Revision changing the model if it is not okay
From http//www.utexas.edu/courses/bio301d/Topic
s/Scientific.method/Text.html
6Model 4 The Inquiry Cycle
Generate alternative competing hypotheses
Summarize and explain Draw conclusions relevant
to other studies
Apply model to other situations, determine its
limits
Find patterns
Experiment to determine correctness of hypothesis
http//thinkertools.soe.berkeley.edu/Pages/curricu
la.html
7Model 5 Inquiry Wheel
- Robinson, W.R. J. Chem. Educ. 2004, 81, 6,
791-792.
8Comparing models
- What are similarities?
- Differences?
- Which model is most useful?
- Which is most comprehensive?
- Which do you like the best?
- What are the key must haves?
9Communication of Inquiry
Lab Report Research Paper Inquiry Models
Introduction/background/questions/hypothesis Experimental/method/procedure Results/data Discussion/evaluation Conclusion/communication Introduction/background/questions/hypothesis Experimental/method/procedure Results/data Discussion/evaluation Conclusion/communication Introduction/background/questions/hypothesis Experimental/method/procedure Results/data Discussion/evaluation Conclusion/communication
If you dont report your work where other
scientist can use it, have you completed the
scientific process??
10Ann Arbor Water
- 1,4-Dioxane from Pall (Gelman)
Carcinogen Between 1976 and 1985, wastewater
containing 1,4 dioxane was sprayed on their lawns
and stored in unlined lagoons.
11Dioxane
12Ann Arbor Water
Huron
Liberty
7th
Stadium
- Picture from http//www.hvcn.org/info/srsw/graph
.JPG
13Water Treatment
- Picture from http//www.mlive.com/aanews/special
/pall/map
14Algae Blooms
15Millers Creek
- Millers Creek
- Eroding banks
- Flooding
http//www.aamillerscreek.org/Watershed.htm
16Finishing Thermochemistry Heat and Phase Change
A
- Why do we cool down when we sweat?
17Silicon-Based Life
Is silicon-based life likely to be more stable or
less stable than carbon-based life?
J. Chem. Ed. 1988, 65, 414.
18Stability of Silicon vs Carbon
- Consider decomposition of alkanes and silanes to
the elements (no oxygen in space for that slug to
worry about). - Consider combustion of silanes and alkanes (will
those silicon-based life forms make it on
earth?).
19Thermochemical Behavior with Respect to Reversion
to the Elements
Si2H6 (g) ? 2 Si (s) 3 H2 (g)
C2H6 (g) ? 2 C(s) 3 H2 (g)
DHof Si2H6 (g) 80.4 kJ/mol
DHof C2H6 (g) -84.7 kJ/mol
DHrxn 0 0 20.9 -80.4 kJ/mol
DHrxn 0 0 (-84.7) 84.7 kJ/mol
Exothermic !
Endothermic!
20A
Enthalpies of Vaporization
H2O(l) ? H2O(g) DH gt0
21Thermochemical Behavior with Respect to Combustion
7/2 O2 (g) Si2H6 (g) ? 2 SiO2 (s) 3 H2O (g)
DHf Si2H6 (g) -80.4 kJ/mol SiO2 (s) -911
kJ/mol H2O(g) -242 kJ/mol CO2 (g) -394
kJ/mol C2H6 (g) -85 kJ/mol
7/2 O2 (g) C2H6 (g) ? 2 CO2 (s) 3 H2O (g)
DHrxn 2(-911) 3(-242) 1(-80.4)
-2468 kJ
DHrxn 2(-394) 3(-242) 1 (-85)
-1429 kJ
Exothermic !
Exothermic!
22Silicon-Based Life
Is silicon-based life likely to be more stable or
less stable than carbon-based life? Thermochemica
l considerations indicate that silicon-based life
would tend to decompose exothermically! Our
space slug unlikely to survive.
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24Water Rights
- Tri-state water war between Georgia, Alabama
and Florida. - The City of Atlanta permit from Corps of
Engineers to create reservoirs on the
Chattahoochee, Flint, and Coosa Rivers - Retain an additional 529 million gallons of water
per day - Stored in Lake Sidney Lanier, Atlanta's major
source of drinking water. - Atlanta's long-term plan included an increase in
withdrawals of 50 from the Chattahoochee and
Flint by the year 2010.
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26Problems
- A 200. g sample of Al is heated in a flame and
then immersed in 500. mL of water in an insulated
container. The initial temperature of the water
was 22.0oC. After the Al and water reach thermal
equilibrium, the temperature of both was 33.6oC.
What was the temperature of the Al just before it
was plunged into the water. - (Al 0.902 J/goC)
27Practice with Units
- The MCL for arsenic is 0.01 mg/L. What is that
in ppm, ppb, M (moles/L)?
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29Problem
- 17) Specifications for lactated Ringers
solution, used for IV injections, are as follows
For each 100 mL of solution - 285-315 mg Na
- 14.1-17.3 mg K
- 4.9-6.0 mg Ca2
- 368-408 mg Cl-
- 231-261 mg C3H5O4-
- Specify the amounts of NaCl, KCl, CaCl22H2O, and
NaC3H5O3needed to prepare 100 mL of lactated
Ringers solution.
30The Polyprotics (Multiples)
- http//www.okinawa.usmc.mil/Public20Affairs20Inf
o/Archive20News20Pages/2003/030131-twins.html
http//www.emory.edu/EMORY_MAGAZINE/spring97/tripl
ets.htmlhttp//www.emory.edu/EMORY_MAGAZINE/spring
97/triplets.html
31H3PO4
- How many acidic protons?
- How many ions in solution?
- Calculate the concentrations of all of the ions
in a 0.1 M solution of phosphoric acid. - How many ICE tables will it take?
32Triprotic Acid
- Phosphoric acid has three acidic protons
- Ka1 6.9 x10-3
- Ka2 6.2 x10-8
- Ka3 4.8 x10-13
- What trend do you observe in the Ka's and what is
the chemical explanation for that trend?
33Titration of H3PO4
34- Ka1 6.9 x10-3
- Ka2 6.2 x10-8
- Ka3 4.8 x10-13
35When pH pKa
- 10 mL 0.1 M H3PO4 add 5 mL 0.1 M NaOH
H3PO4 H2O ? H2PO4- H3O
I C E
x H3O
pKa -log Ka
-logH3O pH
36Shortcuts
37Acid/Base Titration Curves A Closer Look
Plot pH vs. volume of NaOH added.
Equivalence/stoichiometric point ½ equivalence
point
38HA H2O ?? A- H3O
39Are all acid/base titrations the same?
40Titrating Base with Acid
pH at Starting line
What governs the reaction until the equivalence
point is reached?
Whats going on at the stoichiometric point?
What happens after the stoichiometric point?
41Titration of Weak Base with Strong Acid
42Buffers
- http//www.fws.gov/r5crc/Habitat/Riparianbuffers.h
tml
43Acidosis
- Acidosis
- Acidosis is caused by an accumulation of acid or
a significant loss of bicarbonate - Kidney and lungs control your bodys pH
- Lungs cant remove CO2 (an acid)
- Kidney not able to regulate bicarbonate
ingestion of too much acid - Generation of lactic acid upon breakdown of
glucose.
44Buffers
- Acid/base equilibria at work!
- If we need an equilibrium, can strong acids/bases
work as buffers?
- Seeing a buffer in actionhuman buffer simulation
HA H2O ? H3O A- When more acid is added to
this solution H3O A- ? H2O HA When
more base is added, OH- HA ? H2O A-
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46Titration Curves and Buffers
Where does pH change the least while base is
added?
47Looking for a specific pH?
48Henderson-Hasselbalch Rules Buffers
HA H2O ? H3O A-
A-H3O
HA
pH pKa log (A-) HA
logH3O log (A-) HA
49Image from http//cwx.prenhall.com/bookbind/pubb
ooks/hillchem3/medialib/media_portfolio/04.html
50Question 4
- You are given three different aqueous solutions
and told that they each contain either NaOH,
Na2CO3, or NaHCO3. You do some experiments and
gather the following data - Sample A Phenolphthalein is colorless in the
solution. Methyl orange is orange. - Sample B The sample was titrated with HCl until
the pink color of phenolphthalein disappeared,
then methyl orange was added to the solution.
The solution became a pink color. - Sample C Two equal volumes of the sample were
titrated with standardized HCl. Using
phenolphthalein as the indicator, it took 15.00
mL of acid to reach the equivalence point using
methyl orange as the indicator required 30.00 mL
of HCl to achieve neutralization. - Methyl orange changes colors from pH 3.01 (red)
to pH 4.4 (orange) - Phenolphthalein changes color from pH 8 (clear)
to pH 9 (pink)
51- (a) Orange K2Cr2O7(aq) is about to be added to
colorless ethanol (CH3CH2OH(aq)) that has been
acidified with H2SO4. (b) The ethanol solution
becomes colored due to the Cr2O7-2(aq). (c) After
the reaction, the solution becomes a pale violet
color, signifying that the Cr2O7-2(aq) is gone
and that Cr3 is now present (along with CH3COOH)
52(No Transcript)
53Fuel Cells
- H2 ½ O2 ? H2O
- http//science.howstuffworks.com/fuel-cell1.htm
- A fuel cell converts the chemicals hydrogen and
oxygen into water, and in the process it produces
electricity. - Combustion engines like the turbine and the
gasoline engine burn fuels and use the pressure
created by the expansion of the gases to do
mechanical work. Batteries converted chemical
energy back into electrical energy when needed.
Fuel cells should do both tasks more efficiently.
54- the pressurized hydrogen gas (H2) entering the
fuel cell on the anode side. This gas is forced
through the catalyst by the pressure. When an H2
molecule comes in contact with the platinum on
the catalyst, it splits into two H ions and two
electrons (e-). The electrons are conducted
through the anode, where they make their way
through the external circuit (doing useful work
such as turning a motor) and return to the
cathode side of the fuel cell. - Meanwhile, on the cathode side of the fuel cell,
oxygen gas (O2) is being forced through the
catalyst, where it forms two oxygen atoms. Each
of these atoms has a strong negative charge. This
negative charge attracts the two H ions through
the membrane, where they combine with an oxygen
atom and two of the electrons from the external
circuit to form a water molecule (H2O). - This reaction in a single fuel cell produces only
about 0.7 volts. To get this voltage up to a
reasonable level, many separate fuel cells must
be combined to form a fuel-cell stack. - PEMFCs operate at a fairly low temperature (about
176 degrees Fahrenheit, 80 degrees Celsius),
which means they warm up quickly and don't
require expensive containment structures.
Constant improvements in the engineering and
materials used in these cells have increased the
power density to a level where a device about the
size of a small piece of luggage can power a car.
55- Anode side2H2 gt 4H 4e- Cathode sideO2
4H 4e- gt 2H2O - Net reaction2H2 O2 gt 2H2O
56- The electrolyte is the proton exchange membrane.
This specially treated material, which looks
something like ordinary kitchen plastic wrap,
only conducts positively charged ions. The
membrane blocks electrons. - The catalyst is a special material that
facilitates the reaction of oxygen and hydrogen.
It is usually made of platinum powder very thinly
coated onto carbon paper or cloth. The catalyst
is rough and porous so that the maximum surface
area of the platinum can be exposed to the
hydrogen or oxygen. The platinum-coated side of
the catalyst faces the PEM.
57Problems
- H2 sourceHydrogen is difficult to store and
distribute, so it would be much more convenient
if fuel cells could use fuels that are more
readily available. This problem is addressed by a
device called a reformer. A reformer turns
hydrocarbon or alcohol fuels into hydrogen, which
is then fed to the fuel cell. Unfortunately,
reformers are not perfect. They generate heat and
produce other gases besides hydrogen. They use
various devices to try to clean up the hydrogen,
but even so, the hydrogen that comes out of them
is not pure, and this lowers the efficiency of
the fuel cell. - Some of the more promising fuels are natural gas,
propane and methanol. Many people have
natural-gas lines or propane tanks at their house
already, so these fuels are the most likely to be
used for home fuel cells. Methanol is a liquid
fuel that has similar properties to gasoline. It
is just as easy to transport and distribute, so
methanol may be a likely candidate to power
fuel-cell cars. - In the next sections, we will take a look at how
fuel cells
58- How stuff works compares efficiencies
- Biodiesel
59A Copper-Zinc battery What Matters?
What occurs at Copper electrode?
What occurs at Zinc electrode?
Zinc is oxidized and dissolves, mass decreases
Copper plates out, mass increases
Prevent direct reduction of copper at Zinc
electrode Force electrons to flow through
external circuit Allows sulfate ions to flow
maintaining charge balance
60Polymer Structure
61Product Monomer units btwn crosslinks Flexibility Strength
Calculator casing 5-10 small very high
Tires 10-20 restricted high
Tire tubes 20-30 moderate moderate
Artificial heart membrane 30-40 moderate moderate
Kitchen gloves 50-80 moderate low
Surgical gloves 100-150 high low
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63Synthesis Radical
- Monomers which contain a double bond in between
two carbon atoms (called a vinyl group.)
64Radical (Addition) Polymerization
- A radical is an unpaired electron.
- An initiator containing a radical is added to the
vinyl monomer. - The radical steals one of the electrons from the
double bond to form a single bond between the
initiator and one of the carbon atoms. - This leaves an unpaired electron on the other
carbon atom allowing the process to continue.
65Synthesis Condensation
- Do the polymers weigh as much as their monomers?
66Polymer Recycling
- PET - Polyethylene Terephthalate is a transparent
plastic with good gas barrier properties. It is
also relatively cheap and strong. This makes it
especially suitable for producing soft drink
bottles - HDPE - High Density Polyethylene is another
plastic commonly used for drink bottles. It is
translucent and strong with a good resistance
against chemicals. Pigments are used to add color
to HDPE bottles. - PVC - Polyvinyl Chloride is frequently used for
drainage pipes because of its superior chemical
resistance. It also a good insulator and is used
for cable jacketing. - LDPE - Low Density Polyethylene is a tough and
highly flexible plastic that is used for
producing plastic bags, cable jacketing and
bottles. Other applications include products that
can be heat sealed.
Taken from http//www.visionengineer.com/env/plas
tic_recycling_symbols.shtml
67Recycling Continued
- PP - Polypropylene is a strong and light plastic.
It has a relatively high melting point and is
used in products exposed to high temperatures.
These include yogurt and ice cream containers
that are filled while hot. - PS - Polystyrene is rather stiff and rigid. In
this form, it is used in disposable cutlery and
CD jewel cases. Packing foam is also produced by
blowing air bubbles into PS while it is still
setting. - Other - This designation is used for plastic
products that do not fall into any of the other
categories. Further sorting of these items is
required at recycling centers. An example is
melamine, which is often used in plastic plates
an cups. - Which kinds of polymers does Ann Arbor recycle?
Taken from http//www.visionengineer.com/env/plas
tic_recycling_symbols.shtml
68How are Polymers Recycled?
- One of the keys to recycling is the ability to
melt a polymer and reform it. - Thermoplasts Soften and melt when heated, and
therefore can be reshaped. (Ex the polyethylene
used to make a pop bottle) - Thermosets are harder, stiffer and more rigid
than thermoplasts. They are processed at
temperatures above their melting point. Once
they are cooled and become hard they cannot be
reshaped (hence thermo-"set").. (Ex epoxy,
polyester, bakelite, and fiberglass.) - Elastomers are very stretchy, pliable materials,
like anything made out of rubber (Ex rubber
bands or tires)
From www.risfc.org/ print.php?sid452
691998 MMR Vaccine linked to Autism
- From www-student.newn.cam.ac.uk/
nigma/site6/sc.htm
70Autism
- Isolation (some born with it sometimes it seems
to develop) - Many experts argue that improved diagnosis and
deeper awareness among professionals have led to
more accurate and earlier identification of the
problem. Others contend that the absolute number
of cases is rising, not just medicine's ability
to find them. In their view, something in the
environment must be to blame.
71MMR
- Measles (1964) is a virus which causes a rash,
cough, runny nose, eye irritation, and fever in
most people, but can also lead to pneumonia,
seizures, brain damage, and death in some 1 in
2500 cases. - Mumps (1967) virus causes fever, headache, and
swollen glands, but can also lead to deafness,
meningitis, swollen testicles or ovaries, and
death in some cases. - Rubella, (1970) also known as the German Measles,
is generally a mild disease, but can cause
serious birth defects in the child of a woman who
becomes infected while pregnant.
http//www.nlm.nih.gov/medlineplus/ency/article/00
2026.htm
72Measles in the US
- Prior to licensure of the first measles vaccine
in 1963, virtually every person in the U.S. got
the measles by age 20. Since the vaccine became
available, there has been a 99 reduction in the
incidence of measles. However, measles is still
being imported from other countries. The most
recent outbreaks occurred in the U.S. between
1989 and 1991, resulting in 755,000 cases and 123
reported deaths. - From http//www.immunizationinfo.org/vaccineInfo/
vaccine_detail.cfv?id8
73The Triple Vaccine
- Given 15 months and then again at 4-6 or 11-13
years - Mild to moderate side effects
- fever (1 in 6 children)
- rash (1 in 20)
- swollen glands (rare)
- seizure (1 in 3,000)
- Joint pain/stiffness (1 in 4, usually young
women) - low platelet count/bleeding (1 in 30,000)
- Severe adverse effects may include
- allergic reaction (less than 1 per million)
- long-term seizure/brain damage/deafness (so rare
that the association with the vaccine is
questionable)
74Vaccine Source
- Product M-M-R II Manufacturer Merck Year
licensed 1971 - (First used in US and Scandanavia 1972)
- MMR is a live vaccine containing measles, mumps
and rubella viruses that have been modified so
they do not cause symptoms. It produces an immune
response sufficient to protect children from the
diseases.
75- 1988 The MMR (measles, mumps and rubella) triple
vaccine is introduced in the UK, a year after
Britain had a measles outbreak which killed 17
children
76The Wakefield Study
- Ileal-lymphoid-nodular hyperplasia, non-specific
colitis, and pervasive developmental disorder in
children - A J Wakefield, S H Murch, A Anthony, J Linnell, D
M Casson, M Malik, M Berelowitz, A P Dhillon, M
A Thomson, P Harvey, A Valentine, S E Davies, J A
Walker-Smith - The Lancet, Volume 351, Number 9103 28 February
1998 - Inflammatory Bowel Disease Study Group,
University Departments of Medicine and
Histopathology (and the University Departments of
Paediatric Gastroenterology Child and Adolescent
Psychiatry Neurology (and Radiology (Royal Free
Hospital and School of Medicine, London NW3 2QG,
UK - Correspondence to Dr A J Wakefield
77Background
- Evidence gastrointestinal disorders and autism
are linked. - Fudenberg16 noted that for 15 of 20 autistic
children, the first symptoms developed within a
week of MMR vaccination. - Gupta17 commented on the striking association
between measles, mumps, and rubella vaccination
and the onset of behavioral symptoms in all the
children that he had investigated for regressive
autism.
78- Methods 12 children (mean age 6 years range
3-10, 11 boys) were referred to a pediatric
gastroenterology unit with a history of normal
development followed by loss of acquired skills,
including language, together with diarrhea and
abdominal pain. Children underwent
gastroenterological, neurological, and
developmental assessment and review of
developmental records. Ileocolonoscopy and biopsy
sampling, magnetic-resonance imaging (MRI),
electroencephalography (EEG), and lumbar puncture
were done under sedation. Barium follow-through
radiography was done where possible. Biochemical,
haematological, and immunological profiles were
examined. - Findings Onset of behavioural symptoms was
associated, by the parents, with measles, mumps,
and rubella vaccination in eight of the 12
children, with measles infection in one child,
and otitis media in another. All 12 children had
intestinal abnormalities, ranging from lymphoid
nodular hyperplasia to aphthoid ulceration.
Histology showed patchy chronic inflammation in
the colon in 11 children and reactive ileal
lymphoid hyperplasia in seven, but no granulomas.
Behavioural disorders included autism (nine),
disintegrative psychosis (one), and possible
postviral or vaccinal encephalitis (two). There
were no focal neurological abnormalities and MRI
and EEG tests were normal. Abnormal laboratory
results were significantly raised urinary
methylmalonic acid compared with age-matched
controls (p0003), low hemoglobin in four
children, and a low serum IgA in four children. - Interpretation We identified associated
gastrointestinal disease and developmental
regression in a group of previously normal
children, which was generally associated in time
with possible environmental triggers.
79Results
- 9-10 of 12 children developed autism parents
noted behavioral change 24 h to 2 months after
vaccine (15-21 months old) - Some (3) autism diagnoses made by non-hospital
physicians
80Discussion
- Intestinal and behavioral pathologies may have
occurred together by chance, reflecting a
selection bias in a self-referred group however,
the uniformity of the intestinal pathological
changes and the fact that previous studies have
found intestinal dysfunction in children with
autistic-spectrum disorders, suggests that the
connection is real and reflects a unique disease
process. - We did not prove an association between measles,
mumps, and rubella vaccine and the syndrome
described. - If there is a causal link between measles,
mumps, and rubella vaccine and this syndrome, a
rising incidence might be anticipated after the
introduction of this vaccine in the UK in 1988.
Published evidence is inadequate to show whether
there is a change in incidence22 or a link with
measles, mumps, and rubella vaccine.23
81Conclusions
- We have identified a chronic enterocolitis in
children that may be related to neuropsychiatric
dysfunction. In most cases, onset of symptoms was
after measles, mumps, and rubella immunization.
Further investigations are needed to examine this
syndrome and its possible relation to this
vaccine.
82Recommendations
- Suspend MMR vaccination until further data is
collected - Hypothesis the ultimate culprit for the
children's autism was measles virus in the
vaccine
83More Information
- Other research in PhD dissertation from
Wakefields lab Results, no live measles,
mumps, or rubella virus. Conclusion. The results
do not support previous data implicating
persistent measles virus infection with the
aetiology of IBD or autistic enteropathy. - Funded by funds from a group of parents filing a
multibillion dollar lawsuit against the vaccine
companies. - Most patients in the journal study were not
routine admissions, but referred by the lawyers
in the lawsuit.
http//briandeer.com/mmr/wakefield-post.htm
84Investigation Reveals
- Wakefield filed a string of patents for vaccine
and products that would only succeed if MMR
vaccine went down - Ten of the 13 physicians involved in the original
report have withdrawn their support - The Journal editor was a former colleague of
Wakefields.
85Since the Scare
- The Institute of Medicine in Washington, part of
the National Academy of Sciences, has compiled 14
large-scale studies in the United States, Canada
and Europe that all exonerate the vaccine.
Wakefield suggests each study has been flawed
either because of its methodology or because its
authors massaged the findings to get the answers
they sought.
86One Study
- Madsen, K.M., et. al., New England Journal of
Medicine 2002, 347, 19, 1477-1482.) - Introduction
- Studies designed to evaluate the suggested link
between MMR vaccination and autism do not support
an association, but the evidence is weak and
based on case-series, cross-sectional, and
ecologic studies.
87Case series
http//servers.medlib.hscbklyn.edu/ebm/2600.htm
88Cross-sectional
- Collects data all at one time and one time only
from a variety of people, subjects, or
phenomena. Provides a snapshot of the variables
at one particular point in time in a
cross-section of a population. - Data on many variables but increased error
- Data from a large number of subjects
- Data from dispersed subjects but increased cost
with each location - Data on attitudes and behaviors
- Cannot measure change or establish cause and
effect - Good for exploratory research to generate
hypothesis - No control of independent variable
http//www.csulb.edu/msaintg/ppa696/696preex.htm
Cross-Sectional20Design
89Ecologic
- Looks at data on populations or groups of people
for correlations (this group has high blood
pressure and high cancer rates therefore there
might be a link.) - Dales, L. Hammer, S.J. Smith, N. J. JAMA 2001,
285, 9, 1183-1185. - Results Essentially no correlation was observed
between the secular trend of early childhood MMR
immunization rates in California and the secular
trend in numbers of children with autism enrolled
in Californias regional service center system.
For the 1980-1994 birth cohorts, a marked,
sustained increase in autism case numbers was
noted, from 44 cases per 100000 live births in
the 1980 cohort to 208 cases per 100000 live
births in the 1994 cohort (a 373 relative
increase), but changes in early childhood MMR
immunization coverage over the same time period
were much smaller and of shorter duration.
Immunization coverage by the age of 24 months
increased from 72 to 82, a relative increase of
only 14, over the same time period.
90(No Transcript)
91Back to the NEJM study
- Study includes all children born in Denmark
1991-1998 (440,655 received MMR vaccination
96,648 did not) - Conclusions No risk in vaccinated versus
unvaccinated children (adjusted relative risk
0.92) - Increase in autism from 2 cases/10,000 (1980s)
children to 10 cases/10,000 children (1990s)
92Strengths of Study
- Exposure data collected independent of parent
recall and before diagnosis of autism - Autism reporting independent of recording of MMR
vaccine - Controlled for cofounders (age, sex, calendar
period, socioeconomic status, mothers
education, gestational age, and birth weight) - Checked validity of autism diagnosis high since
only specialists in child and adolescent
psychiatry are authorized to code diagnosis of
autism in the Danish Psychiatric Central Register.
93Study Critiques
- Family history of autism not recorded may have
chosen not to receive MMR vaccine. (But would
have expected to see higher risks at beginning of
study before scare.)
94Ethics
M
- Name a situation in science where an ethical
decision must be made?
What behaviors/practices in science would you
consider unethical?
95M
- List all of the ethical issues in the case of
Millikan?
- List all of the ethical issues in the case of
Schön?
How are the situations in the two cases similar?
How are they different?
Did Millikan behave ethically in reporting his
data? Why or why not?
Did Schön behave ethically in reporting his data?
Why or why not?
96M
- If you were faced with a portion of your data
that "didn't fit" your hypothesis what would your
options be?
What are the consequences of publishing incorrect
data?
97From 9/12 Masses of Handfuls of Pennies
M
- 42.43
- 42.43
- 43.53
- 47.54
- 50.075
- 67.606
- 67.874
- 100.140
- 132.73
- 170.20
98Mark and Jerry
A
- List the ethical issues in this case
What are the consequences of reporting the data?
What are the consequences of NOT reporting the
data?
Does the fact that Jerry Elrod tells Mark that
anything under 5 unfavorable results is
insignificant relieve Mark of any further
responsibility?
If Mark wonders whether Jerry's 5 standard for
reporting data meets regulatory standards of
acceptability, how might he go about finding out?
99A
- Under what conditions, if any, do you think it is
ethical for scientists not to report all data in
cases related to pollution?