There has been much controversy over the nature of the institution of slavery, the relative humanity or lack of it in those slave holding nations which practiced it, and its benign or baleful effects upon the blacks on whom it was inflicted. Much has been said about the harshness of Anglo-American slavery and the relatively mild nature of Spanish American slavery, which respected a slave's basic humanity and rights of person, property, and family. Yet little has been done to quantify and document how those attitudes applied in practice. We have had little precise information about the slave family as it existed in the Spanish American colonies and the extent or use of slave property, or about the slaves' access to the legal system that might protect and defend his person, his property, or his family. New sources and methodology have begun to challenge long-held assumptions about both Anglo-American as well as Spanish American slavery. If any conclusion is warranted, it may be that slavery varied widely from place to place and was influenced perhaps as much by differing economic circumstances as by differences in cultural attitudes.

Experiments were conducted from 1989 to 1991 to determine the critical period of johnsongrass control in field corn. Maximum weed-infested and weed-free periods of 0 to 20 wk after corn emergence were maintained by either hand weeding or nicosulfuron application. Interference duration effects on corn grain yield were not affected by johnsongrass control methods. The critical period for johnsongrass control was determined to be between 3 and 6.5 wk after corn emergence to avoid losses above 5% of yield produced by full-season weed-free corn.

Research was conducted to formulate a temperature-dependent population level model for johnsongrass seed germination and rhizome bud break. A nonlinear poikilotherm rate equation was used to describe development rate as a function of temperature, and a temperature-independent Weibull function was used to distribute development times for the population. Seed germination and initiation of rhizome bud break of johnsongrass were collected under constant temperature conditions to parameterize the model. Seed germination rate increased with temperature up to 36 C, then declined at 40 C. Rate of rhizome bud break increased with temperature up to 32 C, then rapidly decreased with further temperature increases. Rate of rhizome bud break was higher than for seed germination at temperatures of 32 C or below, but lower at higher temperatures. Time to first germination or bud break event was longer for seed than for rhizomes, but subsequent progression of development was higher for seed. A population level temperature-dependent model was developed by coupling the poikilotherm equation with the Weibull function. The model was validated against two independent seed germination and three independent rhizome bud germination data sets.

Field experiments were established to investigate the influence of terbufos on the response of five corn hybrids to postemergence applications of CGA-136872. In 1987, Asgrow RX404, Dekalb DK656, Funk's G4673A, and Pioneer P3165 were tolerant to CGA-136872 when no soil insecticides were applied. In 1988, terbufos was applied at 1.1 kg ai ha-1 in-furrow at planting. Injury was observed on all hybrids following CGA-136872 application in 1988. With the exception of Funk's G4307, all hybrids were tolerant to CGA-136872 in 1989 when no soil insecticide was used. When terbufos was applied in-furrow, injury increased with increasing herbicide rate for these hybrids.

Experiments were conducted from 1990 to 1994 to investigate the density-dependent effects of rhizome and seedling johnsongrass on the magnitude of full-season interference in field corn. Corn grain yield was decreased as rhizome johnsongrass density increased. A maximum density of 3 rhizome johnsongrass plants 9.8 m−1 of row was considered critical to avoid yield losses above 5% of full-season weed-free corn. Interference of johnsongrass plants originating from seed and growing at densities up to 128 plants 9.8 m−1 of row did not affect grain yield. Seedling johnsongrass plants growing at a constant density of 9.8 plants m−1 of row did not affect yield from corn planted at five densities.

Research was conducted to determine an effective morningglory control system for cotton grown in central Texas, Prometryn applied PRE or directed-POST applications of methazole or methazole + MSMA did not always adequately control ivyleaf, entireleaf, and seedling sharppod morningglories. However, adequate control of the above species plus pitted morningglory was achieved with a management system that used a dinitroaniline applied PPI or PRE, prometryn applied PRE (0.9 kg ai ha−1), followed by methazole (0.56 kg ha−1) or methazole + MSMA (0.56 + 1.80 kg ha−1) directed POST to cotton 10 to 15 cm high.

Research was conducted to formulate a temperature-dependent population-level model for rhizome johnsongrass flowering. A nonlinear poikilotherm rate equation was used to describe development as a function of temperature and a temperature-independent Weibull function was used to distribute development times for the population. Johnsongrass flowering data were collected under constant temperature conditions to parameterize the poikilotherm rate equation and Weibull function. Coupling the poikilotherm rate equation with the Weibull function resulted in a population level temperature-dependent model. The model was validated against independent field data sets. The model accurately predicted rhizome johnsongrass flowering from plants emerging in the spring. The model performed poorly for plants emerging in summer. Adjustments to the high-temperature inhibition parameter of the poikilotherm rate equation improved model performance in the summer without affecting spring predictions.

We describe here the use of calixarenes, methylene (-CH2-) linked phenolic macrocyclic molecules, to stabilize the formation of quantum-confined (Q-) CdS clusters. Specifically, we focus on the use of an amino-derivatized calixarene, para-[(dimethylamino)- methyl]calix[6]arene, to stabilize Q-CdS clusters which have been characterized by High Resolution TEM (HREM), as well as absorption and emission spectroscopies. Under typical preparative conditions, an average particle diameter of 36 Å is obtained. HREM, in combination with Selected Area Diffraction (SAD), confirms the structure of the clusters as zinc blende CdS. Spectroscopic studies using absorption and emission methods indicate that both particle size and cluster photophysics are sensitive to the ratio of CdS to calixarene.

We describe our complete sample of flat-spectrum radio sources with fluxes >0.5 Jy selected from the Parkes 2700 MHz catalogue. The sample covers all right ascensions and declinations from +10° to −45°, but excluding the galactic plane (b < 10°), and contains some 400 sources.

The social milieu in which slavery took place in Latin America, especially colonial Colombia and Ecuador, was markedly different than in Brazil, the Caribbean, or the thirteen colonies. Paternalistic attitudes of church and government, protective legislation, a slow, even stagnant, pace of economic development and other factors created a situation which a knowledgeable and enterprising slave could often turn to his advantage and even manipulate.

From the beginning the Catholic Church took the position that slavery was a contractual arrangement whereby the slave placed his time and the result of his labor at the disposal of his master, but that he remained a human being with certain innate rights: the right to life, limb, body and reputation. A master could not keep his slaves from marrying, for example, for to do so deprived him of the rights of the body. For a violation of any of these rights the master must make restitution to the slave, as if he were a free man. Moreover, in Catholic theology the soul of the black man was equally as important as the soul of any human being.