Hemispheric asymmetries in semantic processing: Evidences from false memories for ambiguous words

Abstract Previous research suggests that the left hemisphere (LH) focuses on strongly related word meanings; the right hemisphere (RH) may contribute uniquely to the processing of lexical ambiguity by activating and maintaining a wide range of meanings, including subordinate meanings. The present study used the word-lists false memory paradigm [Roediger, H. L. III., & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803-814.] to examine whether these differences between the two cerebral hemispheres in semantic processing also affect memory representations for different meanings of ambiguous words. Specifically, we tested the differences between the LH and RH in recollecting unpresented, semantically related, ambiguous words following the presentation of lists of words all related to either the dominant or the subordinate meanings of these ambiguous words. Findings showed that for the unpresented ambiguous words, the LH made more false alarms than the RH for the dominant lists, whereas the opposite pattern emerged for subordinate lists. Moreover, d 0 analyses showed that, whereas the LH was more sensitive to subordinate than dominant meanings, the RH showed no differences in sensitivity for the two types of word-lists. Taken as a whole, these results support the RH coarse semantic coding theory [Beeman, M. (1998) , 9, 512-518.] indicating that during word recognition, the RH activates and maintains a broader and less differentiated range of related meanings than the LH, including both dominant and subordinate meanings of ambiguous words. Furthermore, the findings suggest that hemispheric differences in ambiguity resolution during language processing extend also to verbal memory

Specificity of pheromonal and kairomonal response of the Israeli pine bast scale Matsucoccus josephi and its predator Elatophilus hebraicus

Abstract-It has been demonstrated previously that the sex pheromone of the Israeli pine bast scale, Matsucoccus josephi, (2E,5R,6E,8E )-5,7-dimethyl-2,6,8-decatrien-4-one (1) is also a potent kairomone of the scale insect's predator Elatophilus hebraicus. Surprisingly, the sex pheromones of M. feytaudi (2) and M. matsumurae (3) also attract E. hebraicus. These results have prompted us to prepare a series of analogs of 1 with variations in the two moieties attached to the C --O group (4-9) in order to probe the structure-activity relationship of the pheromonal / kairomonal response of M. josephi and E. hebraicus. The most selective and active pheromone analog is 8, attracting only M. josephi males and the most selective and active kairomone analog is the M. feytaudi pheromone 2, attracting only adults of E. hebraicus. A dose-response field test of these analogs and the chiral and racemic M. josephi pheromone 1 indicates that the specificity is maintained at a broad range between 25 and 400 mg corresponding to 1. Analog 5, which is neither a parapheromone nor a kairomone, and analog 8, which is only a parapheromone, are not inhibitory to M. josephi or to E. hebraicus. Our study indicates that alterations in the diene side chain of 1, common to all three Matsucoccus pheromones, strongly reduce the kairomonal activity while structural changes in the second side chain significantly reduce the pheromonal activity. The discovery of selective analogs of 1 has practical implications and enables specific monitoring of M. josephi or E. hebraicus. Particularly important is the possibility to mass-trap males of M. josephi without reducing the population of E. hebraicus

Thermal manipulations in late-term chick embryos have immediate and longer term effects on myoblast proliferation and skeletal muscle hypertrophy

We investigated the cellular and molecular bases for the promotion of muscle development and growth by temperature manipulations (TMs) during late-term chick embryogenesis. We show that incubation at 39.5°C (increase of 1.7°C from normal conditions) from embryonic days 16 to 18 (E16 to E18) for 3 or 6 h daily increased diameter of myofibers as of day 13 of age and enhanced absolute muscle growth relative to controls, until day 35 of age. TMs had immediate (E17) and later (up to 2 wk posthatch) effects in elevating muscle cell proliferation relative to controls. This was indicated by higher DNA incorporation of thymidine and a higher number of cells expressing PCNA in intact muscle, accompanied by higher Pax7 levels, all reflecting a higher number of myogenic cells, and suggesting that the increased hypertrophy can be attributed to a higher reservoir of myogenic progeny cells produced in response to the TM. IGF-I levels were higher in the TM groups than in controls, implying a mechanism by which heat manipulations in chicks affect muscle development, with locally secreted IGF-I playing a major role. Whereas hypertrophy was similar in both TM groups, cell proliferation and Pax7 levels were more robust in the 6-h muscle, mainly posthatch, suggesting a differential effect of various TM periods on cell reservoir vs. hypertrophy and a high sensitivity of myoblasts to relatively small changes in heat duration with respect to these processes, which is manifested in the short and long term

Immunization with Recombinant Sao Protein Confers Protection against Streptococcus suis Infection▿

Sao is a Streptococcus suis surface protein recently identified as a potential vaccine candidate. In this study, recombinant Sao in combination with Quil A provided cross-protection against S. suis serotype 2 disease in mouse and pig vaccination protocols. Subcutaneous immunization of mice elicited strong immunoglobulin G (IgG) antibody responses. All four IgG subclasses were induced, with the IgG2a titer being the highest, followed by those of IgG1, IgG2b, and IgG3. Challenge of the mice with S. suis strain 31533 resulted in a mortality rate of 80% for the control group, which received Quil A only. In contrast, all of the mice immunized with Sao survived. In a pig vaccination protocol, intramuscular immunization with Sao also elicited significant humoral antibody responses, and both the IgG1 and IgG2 subclasses were induced, with a predominance of IgG2 production. In vitro assay showed that Sao-induced antibodies significantly promoted the ability of porcine neutrophils in opsonophagocytic killing of S. suis. An aerosol challenge of the pigs with S. suis strain 166 resulted in clinical signs characteristic of S. suis infection in diseased pigs. The vaccine group showed significantly better survival, lower clinical scores, and less S. suis recovery from postmortem tissue samples than did the control group. Furthermore, this study also revealed that although challenge S. suis strains express Sao size variants, recombinant Sao conferred cross-protection. These data demonstrate that recombinant Sao formulated with Quil A triggers strong opsonizing antibody responses which confer efficient immunity against challenge infection with heterologous S. suis type 2