Policing the Races: Attempts to Enforce Racial Purity in Virginia (1630 -1930)

This paper examines Virginia\u27s Racial Purity Laws enacted to deny equal opportunity to black men and women who could pass as whites from the early 1600s to the U. S. Supreme Court decision (Loving v. Virginia) in 1967. When physi­cal charac­teristics failed to match the legal definition of race, the state used records of vital statistics for boundary mainte­nance. Birth certificates, in particu­lar, served as internal passports to school assignments, work eligibility, and marriage, denying citizens defined as Negro life chances available to whites. It was also found that over time the definition of Negro was expanded to include citizens with smaller proportions of African or even Native American blood in their ancestry. An example is presented illustrating how racial identity was defined and enforced

The cause of complications: understanding the relation between post-operative complications and the systems and processes of a hospital by means of an influence diagram

Care for the patient is the core process of hospital care. Hospitals are becoming ever more complex and it is increasingly difficult to have a good overview of the hospital to ensure the quality of care. Among others, additional quality assurance and validation is required to remain in control of the situation. To acquire insight into the most important parameters in patient care, an influence diagram is made of the patient treatment process in the operating room. The outcome of this approach is an extensive diagram, giving an overview of the influences on post-operative complications in a hospital. Based on this, a concise abstraction is made, in which the occurrence of post-operative complications is summarized using a simple system diagram. The main challenges within the current system are identified, and will be used for further research. Preliminary solutions follow from the influence diagram: the essential parameters and the complex interrelations between these parameters are described

Using the right slope of the 970nm absorption feature for estimating canopy water content

Canopy water content (CWC) is important for understanding the functioning of terrestrial ecosystems. Biogeochemical processes like photosynthesis, transpiration and net primary production are related to foliar water. The first derivative of the reflectance spectrum at wavelengths corresponding to the left slope of the minor water absorption band at 970 nm was found to be highly correlated with CWC and PROSAIL model simulations showed that it was insensitive to differences in leaf and canopy structure, soil background and illumination and observation geometry. However, these wavelengths are also located close to the water vapour absorption band at about 940 nm. In order to avoid interference with absorption by atmospheric water vapour, the potential of estimating CWC using the first derivative at the right slope of the 970 nm absorption feature was studied. Measurements obtained with an ASD FieldSpec spectrometer for three test sites were related to CWC (calculated as the difference between fresh and dry weight). The first site was a homogeneous grassland parcel with a grass/clover mixture. The second site was a heterogeneous floodplain with natural vegetation like grasses and various shrubs. The third site was an extensively grazed fen meadow. Results for all three test sites showed that the first derivative of the reflectance spectrum at the right slope of the 970 nm absorption feature was linearly correlated with CWC. Correlations were a bit lower than those at the left slope (at 942.5 nm) as shown in previous studies, but better than those obtained with water band indices. FieldSpec measurements showed that one may use any derivative around the middle of the right slope within the interval between 1015 nm and 1050 nm. We calculated the average derivative at this interval. The first site with grassland yielded an R2 of 0.39 for the derivative at the previously mentioned interval with CWC (based on 20 samples). The second site at the heterogeneous floodplain yielded an R2 of 0.45 for this derivative with CWC (based on 14 samples). Finally, the third site with the fen meadow yielded an R2 of 0.68 for this derivative with CWC (based on 40 samples). Regression lines between the derivative at the right slope of the 970 nm absorption feature and CWC for all three test sites were similar although vegetation types were quite different. This indicates that results may be transferable to other vegetation types and other sites