Fracture in teeth—a diagnostic for inferring bite force and tooth function

Teeth are brittle and highly susceptible to cracking. We propose that observations of such cracking can be used as a diagnostic tool for predicting bite force and inferring tooth function in living and fossil mammals. Laboratory tests on model tooth structures and extracted human teeth in simulated biting identify the principal fracture modes in enamel. Examination of museum specimens reveals the presence of similar fractures in a wide range of vertebrates, suggesting that cracks extended during ingestion or mastication. The use of ‘fracture mechanics’ from materials engineering provides elegant relations for quantifying critical bite forces in terms of characteristic tooth size and enamel thickness. The role of enamel microstructure in determining how cracks initiate and propagate within the enamel (and beyond) is discussed. The picture emerges of teeth as damage-tolerant structures, full of internal weaknesses and defects and yet able to contain the expansion of seemingly precarious cracks and fissures within the enamel shell. How the findings impact on dietary pressures forms an undercurrent of the study.

Falling Labor Share and Rising Unemployment: Long-Run Consequences of Institutional Shocks? CES Germany & Europe Working Papers, No. 00.2, 1999

The literature on unemployment has mostly focused on labor market issues while the impact of capital foonation is largely neglected Job-creation is often thought to be a matter of encouraging more employment on a given capital stock. In contrast, this paper explicitly deals with the long-run consequences of institutional shocks on capital foonation and employment. It is shown that the usual trade off between employment and wages disappears in the long run. In line with an appropriation model, the estimated values for the long-run elasticities of substitution between capital and labor for Germany and France are substantially greater than one.

Revised seasonally adjusted labor force statistics, 1978-87.

The material in this book is supplemented by Employment and earnings and Monthly labor review.

Departments of Labor, Health and Human Services, Education, and related agencies appropriations for 2013 : hearings before a subcommittee of the Committee on Appropriations, House of Representatives, One Hundred Twelfth Congress, second session /

Shipping list no. 2012-0243-P (pt. 1, 4), 2012-0266-P (pt. 2A), 2012-0267-P (pt. 2B), 2012-0250-P (pt. 3), 2013-0038 (pt. 5), 2013-0040-P (pt. 6), 2012-0298-P (pt. 7).

Counting the labor force /

Mode of access: Internet.

Counting the labor force : appendix /

Vol. 3 edited by Diane Werneke.

A profile, professional women in the Dane County labor force.

WI docs. no.: EMP 2.2:W 5/1962

County & municipal labor force report, 1991-2000.

Geographic area includes Adams, Kane, Kankakee, Tazewell, Union, and Woodford Counties, and Addison, Maywood, Moline and Woodridge municipal areas in Illinois.

Labor force information report.

Description based on: Aug. 1977.

Labor force information for affirmative action programs, 1975 : Chicago standard metropolitan statistical area.

Mode of access: Internet.

Labor force information for affirmative action programs, 1978 : [Springfield SMSA].

Chiefly tables.

Youth in the labor force /

Includes bibliographical references.

Some sources of error in labor force estimates from the current population survey /

"August 1978"--Cover.

Survey of occupational mobility, conducted by the cooperating university research centers and the Social Science Research Council for the U. S. Department of the Air Force and the U. S. Bureau of the Census. Voluntary shifts of St. Paul workers 1940-44 and 1945-50.

Mimeographed.

Analysis of Georgia's technical, skilled, and clerical labor requirements and training needs, 1962 to 1967,

"Contract A-636."