Psychotic disorder diagnoses are common in the United States and internationally. However, racial disparities in rates of psychotic disorder diagnoses have been reported across time and mental health professions. This literature review provides an updated and comprehensive summary of empirical research on race and diagnosis of psychotic disorders spanning a 24-year period. Findings reveal a clear and pervasive pattern wherein African American/Black consumers show a rate of on average three to four higher than Euro-American/White consumers. Latino American/Hispanic consumers were also disproportionately diagnosed with psychotic disorders on average approximately three times higher compared to Euro-American/White consumers. In addition, a trend among international studies suggests that immigrant racial minority consumers receiving mental health services may be assigned a psychotic disorder diagnosis more frequently than native consumers sharing a majority racial background. Potential explanations for this phenomenon are discussed, including possible clinical bias and sociological causes such as differential access to healthcare and willingness to participate in mental health services. Directions for future research should include the exploration of disproportionate diagnoses according to race through qualitative interviewing as well as empirical investigation.

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A reliable laboratory index of N availability would be useful for making N recommendations, but no single approach has received broad acceptance across a wide range of soils. We compared several indices over a range of soil conditions to test the possibility of combining indices for predicting potentially mineralizable N (N 0 ). Soils (0-5 and 5-15 cm) from nine tillage studies across the southern USA were used in the evaluations. Long-term incubation data were fit to a fi rst-order exponential

Despite numerous applications of time‐domain reflectometry (TDR), serious difficulties remain in estimating accurate soil water contents under field conditions, especially in fine‐textured soils. We developed a physically based calibration model to predict the frequency‐ and temperature‐dependent complex dielectric response of soils. The model was used to predict frequency‐dependent attenuation and a single “effective” frequency approximation of apparent permittivity of the soil. Effective frequency was predicted to decline from 450 to 160 MHz as water contents increased from air dry to saturation. Predicted frequency decline was small for an input bandwidth of 130 MHz, reflecting that modeled polarization mechanisms associated with relaxation frequencies above 100 MHz were responsible for most of the frequency‐dependent attenuation. For specific surface areas ranging from 150 to 300 m2 g−1, simulations indicate that ignoring dielectric and conductive losses or the associated decline in effective frequency results in a 5 to 22% underestimation of the apparent permittivity. Both the power‐law and de Loor–Dobson mixing models gave a reasonable approximation to the measured apparent permittivity for a silty clay loam (34% clay) across the entire water content range. Moreover, the models were able to describe the behavior of apparent permittivity in response to temperature for two soils with contrasting bulk electrical conductivity contributions to losses. These results demonstrate that loss mechanisms and declines in effective frequency need to be considered to accurately predict the soil water content of fine‐textured soils.

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