Exam 2 T 4/5 in class (bring cheat sheet) Take-home 2 due 4/5

Q&A M 4/4from 5-6:30pmTBA

Today: Smoking andReliable Sources

Tobacco Use in the US, 1900-1999

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

190019051910191519201925193019351940194519501955196019651970197519801985199019952000Year

Per Capita Cigarette Consumption

0

10

20

30

40

50

60

70

80

90

100

Age-Adjusted Lung Cancer Death

Rates*

*Age-adjusted to 2000 US standard population.

Source: Death rates: US Mortality Public Use Tapes, 1960-1999, US Mortality Volumes, 1930-1959, National Center for Health Statistics, Centers for Disease Control and Prevention, 2001. Cigarette consumption: Us Department of Agriculture, 1900-1999.

Per capita cigarette consumption

Male lung cancer death rate

Female lung cancer death rate

Development: differentiating cells to become an organism

Inverse relationship between smoking and weight: more smoking : less weight

Effect of smoking on fetal development and how that can affect adults

Adults exposed to smoke as fetuses have higher risk of obesity and heart disease

What is the connection?

Obesity, Diabetes, Heart Disease, High Blood Pressure, Some Cancers all may have some origins during fetal development.

Adults metabolism may react to poor nutrition as fetuses…

Adaptation of Thriftiness/Catch Up Growth.

Adults metabolism may react to poor nutrition as fetuses…Adaptation of Thriftiness/Catch Up Growth.

Study of babies born during Dutch famine of 1944-45…

Adults metabolism may react to poor nutrition as fetuses…Adaptation of Thriftiness/Catch Up Growth.

Study of babies born during Dutch famine of 1944-45…

20 years later found that these babies had higher rates of obesity.

Adults metabolism may react to poor nutrition as fetuses…Adaptation of Thriftiness/Catch Up Growth.

Study of babies born during Dutch famine of 1944-45…

20 years later found that these babies had higher rates of obesity.

Precise mechanism is not known

What about smoking?

17,000 births studied and checked at age 16 and 33.

Fetuses exposed to smoking had increased rate of obesity.

What about smoking?

17,000 births studied and checked at age 16 and 33.

Fetuses exposed to smoking had increased rate of obesity and more smoking meant more obesity.

What about smoking?

17,000 births studied and checked at age 16 and 33.

Fetuses exposed to smoking had increased rate of obesity and more smoking meant more obesity.

For Mom’s who abstained during pregnancy, no effect on fetus or as adult.

What about smoking?

17,000 births studied and checked at age 16 and 33.

Fetuses exposed to smoking had increased rate of obesity and more smoking meant more obesity.

Smoking during first trimester had same effect as during whole pregnancy.

What about smoking?

For diabetes more than 10 cigarettes per day gave a 4 times greater risk of diabetes.

What about smoking?

Risk of high blood pressure also increases with increased exposure to fetus of smoking during pregnancy

Why?

Why?

Nicotine can inhibit hunger and increase energy expenditure.

This can lead to poor fetal nutrition.

Why?

Nicotine causes constriction of blood vessels, and may limit blood flow to the fetus.

AAL 38.8

Mammalian circulation

Nicotine causes blood vessels to constrict

Why?

CO in blood decreases delivery of O2 to fetus.

Why?

These are all indirect affects leading to “adaptation to thriftiness”…

Nicotine can inhibit hunger and increase energy expenditure.

Nicotine causes constriction of blood vessels, and may limit blood flow to the fetus.

CO in blood decreases delivery of O2 to fetus.

Why?

Nicotine and other toxins in smoke may directly affect hormones that direct fetal development.

Hormones are molecules produced in one cell and signal another.

Why?

Nicotine and other toxins in smoke may directly affect hormones that direct fetal development.

Including hormones that direct brain development.

So,

Smoking during pregnancy may have indirect and/or direct affects on fetal development, and these affects may manifest themselves in adults.

Correlation of weight (BMI) %

Identical twins reared together 80

Identical twins reared apart 72

Fraternal twins reared together 43

Biological siblings 34

Parents and children living together 26

Adopted children and parents 4

Unrelated children living together 1

Nature and Nurture:Correlation of weight and relatedness

The nature of environmental influences on weight and obesity: A behavior genetic analysis. Grilo, Carlos M.; Pogue-Geile, Michael F.; Psychological Bulletin, Vol 110(3), Nov 1991. pp. 520-537. And two books by Matt Ridley: Nature via Nurture (2003) and Genome: the Autobiography of a Species in 23 Chapters (1999)

See:http://sciencenow.sciencemag.org/cgi/content/full/2009/203/3?rss=1(and/or)

Disentangling prenatal and inherited influences in humans with an experimental designFrances Ricea, Gordon T. Haroldb, Jacky Boivinb, Dale F. Hayb, Marianne van den Breea, and Anita ThaparaPNAS early editioncgidoi10.1073pnas.0808798106

Fetal exposure to smoking can have several affects on children, including:-decreased birth weight-increased anti-social behavior

Are these affects genetic or environmental?

In Vitro Fertilization- fertilization occurs in a lab, and then the embryo is implanted into a woman's uterus.

Usually the pregnant woman is related to the embryo, but sometimes they are unrelated.

The average birth weight for all babies born to smoking mothers was lower...

Anti-social behavior was only different if the child and mother were related...

birth weight

anti-social behavior

...So birth weight reductions were strongly nurture (environmental)

...while increases in anti-social behavior were strongly nature (genetic)

Experiment Written Report:Title- Concisely describe your experiment.AuthorAbstract- Summarize your work. Do not exceed 250 words.Introduction-Results-Discussion-Materials and Methods-References- include: author name(s), article title, journal or book title, volume and page number, and year of publication

Staple your approved proposal to the back of your written report.

What is a reliable source?

xkcd.com

Building Blocks of Scientific Literature

peer review

What is peer review?

In a peer reviewed journal each article is looked at by an editor, and then it is then sent to two anonymous reviewers.

These reviewers send comments back to the associate editor.

After each article is sent to the editor, it is then sent to two anonymous reviewers.

These reviewers send comments back to the editor.

They give suggestions for improvement as well as an opinion about whether it should be published or not.

The editor then has three choices:

Accept paper as is. (rare)

Accept paper and ask for some changes.

Reject paper. (20-80% rejection rate in physical sciences*)

*Scholarly Consensus and Journal Rejection Rates. Lowell L. Hargens (Feb., 1988) American Sociological Review 53: 139-151andBang for Your Buck: Rejection Rates and Impact Factors in Ecological Journals. The Open Ecology Journal (2008) L.W. Aarssen, T. Tregenza, A.E. Budden, C.J. Lortie, J. Koricheva and R. Leimu 1: 14-19

Who reviews papers?

Other researchers knowledgeable in the field.

What is a reliable source?

xkcd.com

What is a reliable source?

What is a reliable source?

Can be a great source of sources...

What is a reliable source?

Who was the author(s)?Why was it written?Where was it published?Who checked/reviewed the article?

xkcd.com

Exam 2 T 4/5 in class (bring cheat sheet) Take-home 2 due 4/5

Q&A M 4/4from 5-6:30pmTBA

Today: Smoking andReliable Sources