Stereotypes Possess Heterogeneous Directionality: A Theoretical and Empirical Exploration of Stereotype Structure and Content

We advance a theory-driven approach to stereotype structure, informed by connectionist theories of cognition. Whereas traditional models define or tacitly assume that stereotypes possess inherently Group → Attribute activation directionality (e.g., Black activates criminal), our model predicts heterogeneous stereotype directionality. Alongside the classically studied Group → Attribute stereotypes, some stereotypes should be bidirectional (i.e., Group ⇄ Attribute) and others should have Attribute → Group unidirectionality (e.g., fashionable activates gay). We tested this prediction in several large-scale studies with human participants (N_Combined = 4,817), assessing stereotypic inferences among various groups and attributes. Supporting predictions, we found heterogeneous directionality both among the stereotype links related to a given social group and also between the links of different social groups. These efforts yield rich datasets that map the networks of stereotype links related to several social groups. We make these datasets publicly available, enabling other researchers to explore a number of questions related to stereotypes and stereotyping. Stereotype directionality is an understudied feature of stereotypes and stereotyping with widespread implications for the development, measurement, maintenance, expression, and change of stereotypes, stereotyping, prejudice, and discrimination.     

Chromosomal localization of several families of repetitive sequences by in situ hybridization.

Four recombinant DNA clones (H1, H7, H12, and H15) carrying low-repetitive human DNA were previously isolated from a human genomic library based on their specificity for chromosome 21 and were studied for their distribution as determined by in situ hybridization. Clone H7 hybridized to the satellite regions of chromosomes 13, 14, 15, 21, and 22 as well as to the centromere region of chromosome 1. Clone H12 hybridized strongly to chromosomes 11 and 17 and the centromere of the X. Clones H1 and H15 had a very widespread distribution throughout the genome. Clone H15 hybridized significantly more to the short arm of chromosome 18 than to any other chromosomal segment. Clone H1 hybridized strongly to the centromere of chromosome 19 and also showed random distribution on all the other human chromosomes. We conclude that these probes appear to represent four repetitive families that demonstrate in situ hybridization patterns that do not correspond with those of any other repetitive family. Further, the in situ hybridization patterns do not show the strong chromosome 21 specificity originally defined by Southern blot analysis. The nature and chromosomal localization of these repetitive families should be useful in regional mapping and evolutionary studies and give additional insight into chromosomal organization.     

The Versatility of Human Locomotion

Human locomotion was studied for 160 societies through the use of early travel accounts, missionaries' reports, and the ethnographic literature. As a result of the value Western society has placed on a sedentary way of life, and the consequent devaluation of movement, the common "striding gait" of humans has taken on a kind of misplaced concreteness. Humans facultatively employ a number of locomotor patterns besides the habitual bipedal gait: long-distance running, climbing, leaping, crawling, swimming, and skiing (the latter two are not dealt with in this paper). Human locomotion, like that of animals, is an analogous rather than a univocal concept, admitting great variation, plasticity, and subtle differences in gait, style, speed, and endurance. These multiple concepts have important implications for the construction of models of the evolution of hominid bipedalism.     

Herbicide Chlorsulfuron Decreases Assimilate Transport Out of Treated Leaves of Field Pennycress (Thlaspi arvense L.) Seedlings

Treatment of field pennycress (Thlaspi arvense L.) leaves with the herbicide chlorsulfuron resulted in a decrease in the export of assimilate. Twelve hours after a spot application of 1 microgram, assimilate translocation was 70% of that in control leaves. In excised leaves treated with chlorsulfuron the total amounts of sugars and free amino acids were 150 and 170%, respectively, of the amounts in control leaves, 30 hours after herbicide treatment. The amount of sucrose was 247% of that in control leaves. The increase in the concentration of sucrose in the chlorsulfuron-treated leaves, combined with the absence of an effect of chlorsulfuron on carbon dioxide fixation, suggests that the decrease in assimilate transport is not due to an effect on the synthesis of assimilates, but rather to an effect on their movement out of the leaves. Supplying branched-chain amino acids to the field pennycress seedlings prior to the application of chlorsulfuron prevented the occurrence of the effects described.     

Cross-Resistance of a Chlorsulfuron-Resistant Biotype of Stellaria media to a Triazolopyrimidine Herbicide

A biotype of Stellaria media (L.) Vill. has been identified that is highly resistant to the herbicide chlorsulfuron. Resistance is due to an altered acetolactate synthase (ALS) that is much less sensitive to chlorsulfuron than the ALS from the susceptible (S) biotype. The S biotype was extremely sensitive to D489 (N-[2,6-dichlorophenyl]-5,7-dimethyl-1,2,4-triazolo[1,5a] pyrimidine-2-sulfonamide), a member of a new class of triazolopyrimidine herbicides, while the chlorsulfuron-resistant biotype exhibited complete cross-resistance at both the whole plant and enzyme levels. ALS activity of the S biotype was reduced by approximately 90% in the presence of 0.1 micromolar D489, while that of the R biotype was reduced by less than 10%. This result suggests that the two herbicides share a common binding site on ALS. Only very slight cross-resistance at the ALS level was found to imazamethabenz, an imidazolinone herbicide.     

Genetic control of bacterial suicide: regulation of the induction of PBSX in Bacillus subtilis.

PBSX is a phage-like bacteriocin (phibacin) of Bacillus subtilis 168. Bacteria carrying the PBSX genome are induced by DNA-damaging agents to lyse and produce PBSX particles. The particles cannot propagate the PBSX genome. The particles produced by this suicidal response kill strains nonlysogenic for PBSX. A 5.2-kb region which controls the induction of PBSX has been sequenced. The genes identified include the previously identified repressor gene xre and a positive control factor gene, pcf. Pcf is similar to known sigma factors and acts at the late promoter PL, which has been located distal to pcf. The first two genes expressed from the late promoter show homology to genes encoding the subunits of phage terminases.     

A reusable adapter for collection of cerebrospinal fluid in chronically cannulated goats

A lightweight, adjustable adapter has been designed for chronic cannulation of goats (Capra hircus) which provides an accurate, safe means of sampling cerebrospinal fluid (CSF). This cisternal cannula has been used for continuous perfusion of synthetic CSF into the fourth ventricle in unanesthetized goats. This method also has been used for examining changes in ionic composition of the CSF and cerebral interstitial fluid (ISF) during physiologic adaptations to high altitude (2-5).     

Quantitative electrophoretic transfer of DNA from polyacrylamide or agarose gels to nitrocellulose

A method for efficient electrophoretic transfer of DNA fragments from polyacrylamide gels to nitrocellulose sheets was developed. Hybridization to these fragments can be performed by standard techniques. The method is also applicable to agarose gels, allowing this transfer method to be used for DNA ranging from 40 to at least 23,000 bp.