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Perimenopausal Increase in Serum Cholesterol: A 10-Year Longitudinal Study
van Beresteijn, Emerentia C. H.
Korevaar, Joke C.
Huijbregts, Patricia C. W.
Schouten, Evert G.
Burema, Jan
Kok, Frans J.
ORIGINAL CONTRIBUTIONS
The relative contribution of menopause to the age-related increase in serum total cholesterol concentration in women is not exactly known. Cross-sectional studies suggest a considerable contribution of menopause, whereas in short-term longitudinal studies, only a small increase was observed around menopause In a 10-year follow-up study (1979–1989), serum total cholesterol concentration and dietary intake were measured annually in 167 healthy perimenopausal women (initially aged 49–56 years) who lived in the mixed rural/industrial community of Ede, the Netherlands. The longitudinal design enabled us to study the “natural course” of serum total cholesterol concentration and the influence of dietary fat intake during and after cessation of ovulation. For data analysis, three menopausal cohorts were created based on years relative to menopause: 2 years before (“perimenopausal”), 2 years after (“early post-menopausal”), and 6 years after (“late postmenopausal”). In each cohort, the analysis was conducted on data from 4 years of follow-up. The results show that from 2 years before to 6 years after menopause, serum total cholesterol concentration increased on average by at least 1 1 mmol/liter (19%). Thereafter, only a minor increase was observed. The rise was significantly lower in women who increased their intake of polyunsaturated fatty acids as compared with women who reduced their intake during that period. It is concluded that cessation of ovulation appears to be associated with a major increase of 19% in serum total cholesterol concentration during an 8-year period around menopause. This increase may be reduced by increasing the intake of polyunsaturated fatty acids.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/383
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Copyright (C) 1993, Oxford University Press
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Diet and Endometrial Cancer: A Case-Control Study
Barbone, Fabio
Austin, Harland
Partridge, Edward E.
ORIGINAL CONTRIBUTIONS
A case-control study of 168 cases with endometrial cancer and 334 controls was conducted in Birmingham, Alabama, between June 1985 and December 1988. Cases were identified at the University of Alabama Hospital and in a private practice; controls were selected from among women who attented the University optometry clinic. A food frequency questionnaire that evaluated the intake of 55 nutrients and 116 foods was obtained for 103 cases and 236 controls. Logistic regression was used to evaluable the effect of diet on endometrial cancer after adjustment for total calones, age, race, education, obesity, smoking status, age at menarche, number of pregnancies, age at menopause, diabetes, hypertension, and use of exogenous estrogens. High intake of certain micronutrients was associated with a decreased risk of endometrial cancer, the odds ratio for subjects in the upper tertile versus those in the lower tertile was 0.4 for both carotene and nitrate (95% confidence interval (CI) 0 2–0 8 and 0.2–0.9, respectively). There also was an inverse association between endometrial cancer and protein consumption (trend test; <it>p</it> = 0 002), and a moderate direct association with cholesterol intake (OR = 1.9, 95% CI 0.9–3.7) when terms for both these macronutrients were included in a logistic model. Total intake of animal and vegetables fat were not associated with endometrial cancer. More frequent consumption of several vegetables and certain dairy products was associated with a statistically significant decreased risk of endometrial cancer. These results suggest that diet plays an important role in the etiology of endometrial cancer.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/393
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4042015-05-11HighWireOUPamjepid:137:4
Calcium, Magnesium, and Free Fatty Acids in the Formation of Gallstones: A Nested Case-Control Study
Rudnicki, Martin
Jørgensen, Torben
Jensen, Kirsten Hougaard
Thode, Jørgen
ORIGINAL CONTRIBUTIONS
In a nested case-control study, calcium status was assessed by measurements of serum total calcium, magnesium, phosphate, ionized calcium, parathyroid hormone, albumin, total CO<inf>2</inf> (bicarbonate), and free fatty acids in relation to gallstone formation The subjects were recruited from a cohort study (<it>n</it> = 4,581) on the epidemiology of gallstones in Denmark. The cohort was examined with ultrasonography twice, in 1983 and 1988; 63 subjects developed gallstones, and among those who did not, 122 were randomly selected as controls Subjects with gallstones had significantly increased serum concentrations of total calcium, magnesium, and bicarbonate as compared with normal subjects. The difference was only observed in women Age, body mass index, alcohol consumption, and smoking did not influence the results when included as covariables in a logistic regression analysis Multivanate analysis showed increased concentrations of magnesium, bicarbonate, and parathyroid hormone to be significantly associated with gallstone disease in women No significant association was observed between gallstone disease and serum variables in men.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/404
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4092015-05-11HighWireOUPamjepid:137:4
Copper in Human Mammary Carcinogenesis: A Case-Cohort Study
Overvad, Kim
Wang, Dennis Y
Olsen, Jøm
Allen, Diane S
Thorling, Eivind B.
Bulbrook, Richard D
Hayward, John L.
ORIGINAL CONTRIBUTIONS
In 1968–1975, a cohort of 5,100 ostensibly healthy women was established on the island of Guernsey, England, for investigation of the influence of hormonal factors on breast cancer. At the women's entry into the study, blood samples were drawn from each participant, and each woman completed a questionnaire that provided information on established risk indicators in human mammary carcinogenesis. Plasma copper levels were measured in 46 breast cancer cases diagnosed an average of 11 years (standard deviation (SD), 4) after entry into the study cohort and in an age-stratified random sample of 138 women drawn from the total initial cohort at risk Plasma copper levels were 1.31 mg/liter (SD, 037) in the cases and 1 26 mg/liter (SD, 0.36) in the controls; the 95% confidence interval for the overall difference was −0 07 to 0.17. A U-shaped relation between premorbid plasma copper levels and the risk of developing breast cancer was seen Adjusted odds ratios for breast cancer were 1.8, 1.0, 1.6, and 3.2, respectively, in the four quartiles of the copper distribution. No major changes in the risk estimates were observed when statistical evaluation was restricted to cases diagnosed more than 10 years after collection of blood samples.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/409
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4152015-05-11HighWireOUPamjepid:137:4
Maternal Risk Factors for Congenital Syphilis: A Case-Control Study
Webber, Mayns P.
Lambert, Genevieve
Bateman, David A.
Hauser, W. Allen
ORIGINAL CONTRIBUTIONS
This study estimated the strength of association between maternal cocaine use and congenital syphilis after adjustment for other factors, especially the use of prenatal care. The authors reviewed medical chart and laboratory data for 75 liveborn infants treated for congenital syphilis at Harlem Hospital Center (New York City) in 1987, 150 matched control infants, and their mothers. Cocaine use was determined from universal maternal medical histories and infant toxicology screenings, and the sensitivity of each method of ascertainment was evaluated. With the use of either maternal history or positive infant urine toxicology as evidence of cocaine use, 66.2% (49/74) of case infants versus 16 1% (24/149) of control infants were judged to have been exposed to cocaine in utero (odds ratio (OR) = 91, 95% confidence interval (CI) 4.7–292) However, in multiple logistic regression, lack of prenatal care was the single variable with the highest adjusted odds ratio (adjusted OR = 11.0, 95% CI 1.3–93 1); maternal cocaine use had the second-highest adjusted odds ratio (adjusted OR = 4.9, 95% CI 1.8–13.0). Thus, despite the emergence of maternal cocaine use as a new risk factor, underutilization of prenatal care remains the strongest predictor of congenital syphilis.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/415
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4232015-05-11HighWireOUPamjepid:137:4
Trends in the Incidence of Outcomes Defining Acquired Immunodeficiency Syndrome (AIDS) in the Multicenter AIDS Cohort Study: 1985-1991
Muñoz, Alvaro
Schrager, Lewis K.
Bacellar, Helena
Speizer, Ilene
Vermund, Sten H
Detels, Roger
Saah, Alfred J.
Kingsley, Lawrence A.
Seminara, Daniela
Phair, John P.
ORIGINAL CONTRIBUTIONS
Incidence of clinical outcomes defining acquired immunodeficiency syndrome (AIDS) may be expected to change as a consequence of progressive immunosuppression and use of chemoprophylaxis before the onset of AIDS. Using Poisson regression methods, we examined trends in the incidence of initial and secondary AIDS-defining illnesses from 1985 to 1991 among 2,627 homosexual men participating in the Multicenter AIDS Cohort Study who were seropositive for human immunodeficiency virus type 1. The incidence of <it>Pneumocystis carinii</it> pneumonia rose steeply until 1987 but has declined since then (<it>P</it> < 0.001), while the other AIDS-defining conditions have showed significant (<it>P</it> ≤ 0.039) upward trends. Trends for Kaposi's sarcoma, lymphoma, neurologic disease, and cytomegalovirus/herpes simplex virus infections were explained by progressive immunosuppression, but residual downward and upward trends were present for <it>P. carinii</it> pneumonia and other opportunistic infections (bacterial, fungal, and protozoal infections and wasting syndrome). Despite selection bias, those receiving <it>P. carinii</it> pneumonia chemoprophylaxis showed a significantly lower incidence of <it>P. carinii</it> pneumonia (relative risk = 0.32, 95% confidence interval 0.16–0.63), and the time trends of <it>P. carinii</it> pneumonia were explained by progressive immunosuppression and use of prophylaxis. No significant effects on all other diagnoses were seen in those selected to receive antiretroviral therapy. Secondary diagnoses showed a strongly significant (<it>P</it> < 0.001) increase in non-<it>P. carinii</it> pneumonia and non-Kaposi's sarcoma among those with initial diagnoses of Kaposi's sarcoma. Overall, the trend observed in the incidence of other opportunistic infections underscores the need for developing and testing new strategies to curtail or delay the onset of these diseases.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/423
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4392015-05-11HighWireOUPamjepid:137:4
Clinical Factors Associated with Weight Loss Related to Infection with Human Immunodeficiency Virus Type 1 in the Multicenter AIDS Cohort Study
Graham, Neil M. H.
Muñoz, Alvaro
Bacellar, Helena
kingsley, Lawrence A
Visscher, Barbara R.
Phair, John P.
ORIGINAL CONTRIBUTIONS
The relation between a number of potential risk factors and change in body mass index per semester was examined in a community-based cohort of 1,809 homosexsual and bisexual men seropositive for human immunodeficiency virus type 1 (HIV-1). The men were followed semiannually for up to 6.5 years between 1984 and 1990. A total of 9,735 person-semesters of observations were available for analysis. A Markov-type autoregressive model, adjusting for previous body mass index, was used to predict the change in body mass index over each person-semester. Overall, the cohort was gaining weight An asymptomatic participant 1.8m in height whose CD4+cell count was >750/μl gained a mean of 0.5 kg each person-semester. In bivariate autoregressive models, diarrhea, fever, oral thrush, acquired immunodeficiency syndrome (AIDS), and CD4+lymphocyte counts of <100 and 100–199 cell/μl were all associated with a significant decrease in body mass index. A significant inverse association was also found between change in body mass index and lymphadenopathy and herpes zoster, but when the intercept coefficient was added, no overall decrease in body mass index was seen in these models. In a final multivarite model, diarrhea was less strongly associated with a change in body mass index (<it>p</it> = 0.057), althougth AIDS (<it>p</it> = 0.009), fever (<it>p</it> = 0.006), thrush (<it>p</it> = 0.002), and a CD4+lymphocyte count of <100 cell/μl (<it>p</it> < 0.001)all remained independently associated with a decrease in body mass index. Lymphadenopathy and a CD4+ lymphocyte count of 100–199 cells/μl were also significant covariates in the final model, but neither of the beta coefficients exceeded that of the intercept, indicating that they were not independently associated with a decrease in body mass index. These findings suggest that the importance of diarrhea as a cause of HIV-related weight loss may have been over -estimated in previous clinic-based studies. AIDS and nonspecific markers of progression (fever, thrush, and a CD4+ count of <100 cells/μl) were the best predictors of weight loss during a semester.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/439
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4472015-05-11HighWireOUPamjepid:137:4
Assessment of Blood Lead Levels in Children Living in a Historic Mining and Smelting Community
Cook, Magdalena
Chappell, Willard R.
Hoffman, Richard E.
Mangione, Ellen J.
ORIGINAL CONTRIBUTIONS
Lead poisoning in childhood is an important public health problem, and thus, it is important to determine how children are exposed to lead. In 1987, the authors conducted an exposure assessment and blood lead screening for children aged 6–71 months living in Leadville, Colorado. High levels of lead had been found in the soil as a result of both past mining and smelting activities and natural mineralization. Blood was collected from each child for lead analysis, and behavioral characteristics were identified through an interview with a parent or guardian. Three sources of exposure to lead were associated with blood lead levels: lead in a core sample taken from the backyard of the family's home, lead brought home on the clothes of a miner, and lead from soldering in the home. Two pathways of exposure were associated with blood lead levels: the child swallowing things other than food, and taking food or a bottle outside to play. Multivariate regression using these variables found effect modification by age. For children aged 6–36 months, only sources of exposure were independent predictors of blood lead levels, while in children aged 37–71 months, a pathway of exposure in addition to sources of exposure independently predicted blood lead levels.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/447
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4562015-05-11HighWireOUPamjepid:137:4
Association of Education with Reported Age of Onset and Severity of Alzheimer's Disease at Presentation: Implications for the use of Clinical Samples
Montz, Deborah J.
Petitti, Diana B.
ORIGINAL CONTRIBUTIONS
Clinical samples are commonly used to attempt to infer factors that are etiologically important in Alzheimer's disease. Use of clinical samples for these purposes is valid if and only if detection of Alzheimer's disease is unbiased with respect to the factors being studied. The issue of how education influences detection of Alzheimer's disease is controversial. The purpose of the present inverstigation was to shed light on the role of education in the detection of symptoms of Alzheimer's disease. To do so, we examined the association of education with age of symptom onset, severity of disease at diagnosis, and time from symptom onset until diagnosis in a large clinical sample of Alzheimer's disease patients from throughout California. The diagnosis of the 1,658 cases in the sample were made in 1985–1990. Age of onset was defined as the age at which symptoms first appeard, according to family members. Severity of dementia was measured with Blessed-Roth Dementia Rating Scale scores The reported age at symptom onset was later in those with less education (<it>p</it> < 0.0001). However, decreaseing education was associated with greater severity of disease at presentation (<it>p</it> < 0.008), suggesting that a lower educational level may lead to later detection of Alzheimer's disease and referral to clinical centers at a later stage of disease. This implies that using clinical samples of Alzheimer's disease patients to study factors correlated with age at onset may lead to biased conclusions, if these factors are also associated with education.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/456
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4632015-05-11HighWireOUPamjepid:137:4
A Novel Approach to the Characterization of Cumulative Exposure for the Study of Chronic Occupational Disease
Seixas, Noah S.
Robins, Thomas G
Becker, Mark
ORIGINAL CONTRIBUTIONS
Inappropriate parameterization of an exposure metric for the study of occupational and environmental hazards may lead to significant misclassification and biased results. A model for identification of an optimal expression for cumulative exposure that includes exponentiated terms for concentration and time was developed. When the values of the exponents are allowed to vary, an optimal expression for cumulative exposure may be identified. The approach has advantages for the study of chronic hazards, in that it is flexible, limits the number of assumptions, and incorporates many of the models generally suggested in the literature. In addition, the model results may be interpreted to suggest particular pathophysiologic mechanisms. The model was implemented with data from a previously studied cohort of underground coal miners, and the associations between the exposure metric and measures of obstructive lung disease were identified. The results demonstrated that the exposure metric can improve the association of dust exposure histories with various outcomes over the usual measure of cumulative exposure. However, in the particular data set used, the overall predictive power of alternative models was similar and the interpretability of the results was limited.
Oxford University Press
1993-02-15 00:00:00.0
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http://aje.oxfordjournals.org/cgi/content/short/137/4/463
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Copyright (C) 1993, Oxford University Press
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Comparison of Three Methods of Establishing Odds Ratios from a Job Exposure Matrix in Occupational Case-Control Studies
Bouyer, Jean
Hémon, Denis
ORIGINAL CONTRIBUTIONS
A job exposure matrix consists of jobs on one axis and substances on the other, with matrix elements describing the likelihood of an individual's exposure to a substance in a given job. This can be used in case-control studies to infer exposures of subjects whose jobs are known. The simplest form of job exposure matrix contains binary entries, but it is also possible to envisage continuous variables describing the probabiltity of exposure in the job (probabilistic matrix). In such a case, the user has various options for transforming and analyzing the data, including the following; 1) transform to binary variables and analyze as conventional binary exposure variables; 2) leave as continuous variables and analyze using logistic regression; 3) leave as continous variables and analyze using a linear model Simulations were carried out to compare the ability of the three methods to estimate odds ratios under 36 experimental conditions. The linear model produced unbiased estimates, the logistic model produced somewhat biased estimates at high odds ratios, and the transformation to a binary variable produced systematically low estimates in most experimental circumstances. With the linear and logistic models, the odds ratio estimators had similar precision when the bias of the latter was not too great. The authors conclude that the linear model permits optimal use of a probablistic matrix in an epidemiologic study and hope that these results will encourage the development of job exposure matrices containing probabilites rather than dichotomes.
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/472
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/482-a2015-05-11HighWireOUPamjepid:137:4
RE: "A SIMPLE, VALID STEP TEST FOR ESTIMATING MAXIMAL OXYGEN UPTAKE IN EPIDEMIOLOGIC STUDIES;"
Witkov, Carey
LETTERS TO THE EDITOR
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/482-a
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Copyright (C) 1993, Oxford University Press
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RE: "RISK FACTORS FOR MORTALITY FROM ALL CAUSES AND FROM CORONARY HEART DISEASE AMONG PERSON WITH DIABETES. FINDINGS FROM THE NATIONAL HEALTH AND NUTRITION SURVEY I EPIDEMIOLOGIC FOLLOW-UP STUDY"
Jarrett, R. J.
LETTERS TO THE EDITOR
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/482
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/4832015-05-11HighWireOUPamjepid:137:4
THE FIRST AUTHOR REPLIES
Siconolfi, Steven F.
LETTERS TO THE EDITOR
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/483
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Copyright (C) 1993, Oxford University Press
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Re: "Risk factors for mortality from all causes and from coronary heart disease among persons with diabetes: findings from the National Health and Nutrition Survey I Epidemiologic Follow-up Study"
Jarrett, RJ
LETTERS TO THE EDITOR
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/482a
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Copyright (C) 1993, Oxford University Press
oai:open-archive.highwire.org:amjepid:137/4/482b1993-02-15HighWireOUPamjepid:137:4
Re: "A simple, valid step test for estimating maximal oxygen uptake in epidemiologic studies"
Witkov, C
LETTERS TO THE EDITOR
Oxford University Press
1993-02-15 00:00:00.0
TEXT
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http://aje.oxfordjournals.org/cgi/content/short/137/4/482b
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Copyright (C) 1993, Oxford University Press