Cricket frogs (Acris crepitans) from several different sites in Illinois were collected to assess the effects of environmental contamination on the prevalence of intersex gonads. Of 341 frogs collected in 1993, 1994, and 1995, 2.7% were intersex individuals. There was no statistically significant relationship between the chemical compounds detected and cricket frog intersexuality. However, there was an association approaching significance (p = 0.07) between the detection of atrazine and intersex individuals. A comparison of reference sites with sites that had point polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF) contamination revealed a significant relationship between sex-ratio reversal and contamination with PCBs and PCDFs. The sex ratio of juvenile frogs studied from three sites with PCB and PCDF point contamination favored males over females, which was the opposite of the sex ratio in control ponds (p = 0.0007). The statistically significant correlation between organochlorine contamination and sex-ratio reversal suggests PCBs and PCDFs can influence cricket frog sexual differentiation. The current study suggests that in cricket frogs, sex ratios and the prevalence of intersex gonads are altered by environmental contamination.ImagesFigure 1Figure 2

Exposure to anthropogenic endocrine disruptors has been listed as one of several potential causes of amphibian declines in recent years. We examined gonads of 814 cricket frogs (Acris crepitans) collected in Illinois and deposited in museum collections to elucidate relationships between the decline of this species in Illinois and the spatial and temporal distribution of individuals with intersex gonads. Compared with the preorganochlorine era studied (1852–1929), the percentage of intersex cricket frogs increased during the period of industrial growth and initial uses of polychlorinated biphenyls (PCBs) (1930–1945), was highest during the greatest manufacture and use of p,p-dichlorodiphenyltrichloroethane (DDT) and PCBs (1946–1959), began declining with the increase in public concern and environmental regulations that reduced and then prevented sales of DDT in the United States (1960–1979), and continued to decline through the period of gradual reductions in environmental residues of organochlorine pesticides and PCBs in the midwestern United States (1980–2001). The proportion of intersex individuals among those frogs was highest in the heavily industrialized and urbanized northeastern portion of Illinois, intermediate in the intensively farmed central and northwestern areas, and lowest in the less intensively managed and ecologically more diverse southern part of the state. Records of deposits of cricket frog specimens into museum collections indicate a marked reduction in numbers from northeastern Illinois in recent decades. These findings are consistent with the hypothesis that endocrine disruption contributed to the decline of cricket frogs in Illinois.

This study examines the impacts of maternal and paternal influences on the educational attainment of women and whether these parental effects operate similarly for white and black women. Specifically, the study measures the differential effects of mother's and father's education, occupation, and encouragement. Using data from the National Longitudinal Survey of Labor Market Experience ( N U ) , 428 white and 145 black women were examined. Findings indicate different patterns in the way mothers and fathers affect their daughters' educational attainments. For both groups of women, father's education was found to be a generally better predictor than mother's education, while mother's occupation was more important than father's occupation. Mother's occupation and parental expectation variables were relatively more important for black women, and parental education variables were more important for white women.Increasing interest in the status attainment of women reflects an important change in traditional thought, which at one time considered the social position of females almost entirely in terms of the accomplishments of their fathers or husbands (Parsons, 1954;Turner, 1964). Women have rightly become a more important focus of sociological research (see Falk and Cosby, 1975,1978). Their educational and occupational accomplishments are usually studied using a model of socialization based on earlier research involving males (Alexander and Eckland, 1974;Sewell and Shah, 1968;Treiman and Terrell, 1975; Waite and Moore, 1978). The first aim of this study was to reexamine certain aspects of this approach in order to determine whether there are differential parental influences on women's educational achievement. Our emphasis was not on comparisons between males and females; rather, we were concerned with the relative importance of certain variables in the model for a representative group of young women. The second objective of this research was to determine whether parental influences on educational attainment operate differently for black and white women. Given our interest in sex-and race-specific influences on the attainment process, we briefly review previous research that addresses each of these issues.

No abstract