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1.
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 (NCombined = 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. 相似文献
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4.
Chromosomal localization of several families of repetitive sequences by in situ hybridization. 总被引:2,自引:1,他引:1
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E A Devine S L Nolin G E Houck Jr E C Jenkins W T Brown 《American journal of human genetics》1985,37(1):114-123
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. 相似文献
5.
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. 相似文献
6.
Herbicide Chlorsulfuron Decreases Assimilate Transport Out of Treated Leaves of Field Pennycress (Thlaspi arvense L.) Seedlings 总被引:1,自引:0,他引:1
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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. 相似文献
7.
Cross-Resistance of a Chlorsulfuron-Resistant Biotype of Stellaria media to a Triazolopyrimidine Herbicide 总被引:1,自引:1,他引:0
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. 相似文献
8.
We have broadly defined the DNA regions regulating esterase6 activity in
several life stages and tissue types of D. melanogaster using P-
element-mediated transformation of constructs that contain the esterase6
coding region and deletions or substitutions in 5' or 3' flanking DNA.
Hemolymph is a conserved ancestral site of EST6 activity in Drosophila and
the primary sequences regulating its activity lie between -171 and -25 bp
relative to the translation initiation site: deletion of these sequences
decrease activity approximately 20-fold. Hemolymph activity is also
modulated by four other DNA regions, three of which lie 5' and one of which
lies 3' of the coding region. Of these, two have positive and two have
negative effects, each of approximately twofold. Esterase6 activity is
present also in two male reproductive tract tissues; the ejaculatory bulb,
which is another ancestral activity site, and the ejaculatory duct, which
is a recently acquired site within the melanogaster species subgroup.
Activities in these tissues are at least in part independently regulated:
activity in the ejaculatory bulb is conferred by sequences between -273 and
-172 bp (threefold decrease when deleted), while activity in the
ejaculatory duct is conferred by more distal sequences between -844 and
-614 bp (fourfold decrease when deleted). The reproductive tract activity
is further modulated by two additional DNA regions, one in 5' DNA (-613 to
-284 bp; threefold decrease when deleted) and the other in 3' DNA (+1860 to
+2731 bp; threefold decrease when deleted) that probably overlaps the
adjacent esteraseP gene. Collating these data with previous studies
suggests that expression of EST6 in the ancestral sites is mainly regulated
by conserved proximal sequences while more variable distal sequences
regulate expression in the acquired ejaculatory duct site.
相似文献
9.
Genetic control of bacterial suicide: regulation of the induction of PBSX in Bacillus subtilis. 总被引:2,自引:1,他引:1
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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. 相似文献
10.
Litman GW; Rast JP; Shamblott MJ; Haire RN; Hulst M; Roess W; Litman RT; Hinds- Frey KR; Zilch A; Amemiya CT 《Molecular biology and evolution》1993,10(1):60-72
Immunoglobulins are encoded by a large multigene system that undergoes
somatic rearrangement and additional genetic change during the development
of immunoglobulin-producing cells. Inducible antibody and antibody-like
responses are found in all vertebrates. However, immunoglobulin possessing
disulfide-bonded heavy and light chains and domain-type organization has
been described only in representatives of the jawed vertebrates. High
degrees of nucleotide and predicted amino acid sequence identity are
evident when the segmental elements that constitute the immunoglobulin gene
loci in phylogenetically divergent vertebrates are compared. However, the
organization of gene loci and the manner in which the independent elements
recombine (and diversify) vary markedly among different taxa. One striking
pattern of gene organization is the "cluster type" that appears to be
restricted to the chondrichthyes (cartilaginous fishes) and limits
segmental rearrangement to closely linked elements. This type of gene
organization is associated with both heavy- and light-chain gene loci. In
some cases, the clusters are "joined" or "partially joined" in the germ
line, in effect predetermining or partially predetermining, respectively,
the encoded specificities (the assumption being that these are expressed)
of the individual loci. By relating the sequences of transcribed gene
products to their respective germ-line genes, it is evident that, in some
cases, joined-type genes are expressed. This raises a question about the
existence and/or nature of allelic exclusion in these species. The
extensive variation in gene organization found throughout the vertebrate
species may relate directly to the role of intersegmental
(V<==>D<==>J) distances in the commitment of the individual
antibody-producing cell to a particular genetic specificity. Thus, the
evolution of this locus, perhaps more so than that of others, may reflect
the interrelationships between genetic organization and function.
相似文献