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Little is known about the effects of enriched CO(2) atmospheres, which may exist in the next century, on natural plant-insect herbivore interactions. Larvae of a specialist insect herbivore, Junonia coenia (Lepidoptera: Nymphalidae), were reared on one of its host plants, Plantago lanceolata (Plantaginaceae), grown in either current low (350 parts per million) or high (700 ppm) CO(2) environments. Those larvae raised on high-CO(2) foliage grew more slowly and experienced greater mortality, especially in early instars, than those raised on low-CO(2) foliage. Poor larval performance on high-CO(2) foliage was probably due to the reduced foliar water and nitrogen concentrations of those plants and not to changes in the concentration of the defensive compounds, iridoid glycosides. Adult pupal weight and female fecundity were not affected by the CO(2) environment of the host plant. These results indicate that interactions between plants and herbivorous insects will be modified under the predicted CO(2) conditions of the 21st century. 相似文献
123.
Rausher MD 《Science (New York, N.Y.)》2007,315(5811):461; author reply 461
Although Whibley et al. (Reports, 18 August 2006, p. 963) argue for the presence of high-fitness ridges in the Antirrhinum floral-color adaptive landscape, their data are equally compatible with adaptive landscapes having a single peak and no ridges. Their demonstration of divergent selection across a hybrid zone argues against the presence of adaptive ridges. 相似文献
124.
Does rejection hurt? An FMRI study of social exclusion 总被引:1,自引:0,他引:1
A neuroimaging study examined the neural correlates of social exclusion and tested the hypothesis that the brain bases of social pain are similar to those of physical pain. Participants were scanned while playing a virtual ball-tossing game in which they were ultimately excluded. Paralleling results from physical pain studies, the anterior cingulate cortex (ACC) was more active during exclusion than during inclusion and correlated positively with self-reported distress. Right ventral prefrontal cortex (RVPFC) was active during exclusion and correlated negatively with self-reported distress. ACC changes mediated the RVPFC-distress correlation, suggesting that RVPFC regulates the distress of social exclusion by disrupting ACC activity. 相似文献
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A high-temperature plasma is created when an intense laser pulse is focused onto the surface of a solid. An ultrafast pulse of x-ray radiation is emitted from such a plasma when the laser pulse length is less than a picosecond. A high-speed streak camera detector was used to determine the duration of these x-ray pulses, and computer simulations of the plasmas agree with the experimental results. Scaling laws predict that brighter and more efficient x-ray sources will be obtained by the use of more intense laser pulses. These sources can be used for time-resolved x-ray scattering studies and for the development of x-ray lasers. 相似文献
127.
Queens of Lasioglossum zephyrum, a primitively eusocial bee, are considerably more active than workers. The queen's behavior stimulates worker activities; removal of the queen results in a marked reduction in activities of other bees. The queen not only activates workers but also directs them by a primitive recruitment behavior suggestive of tandem running of highly eusocial ants. 相似文献
128.
Terracciano A Abdel-Khalek AM Adám N Adamovová L Ahn CK Ahn HN Alansari BM Alcalay L Allik J Angleitner A Avia MD Ayearst LE Barbaranelli C Beer A Borg-Cunen MA Bratko D Brunner-Sciarra M Budzinski L Camart N Dahourou D De Fruyt F de Lima MP del Pilar GE Diener E Falzon R Fernando K Ficková E Fischer R Flores-Mendoza C Ghayur MA Gülgöz S Hagberg B Halberstadt J Halim MS Hrebícková M Humrichouse J Jensen HH Jocic DD Jónsson FH Khoury B Klinkosz W Knezević G Lauri MA Leibovich N Martin TA 《Science (New York, N.Y.)》2005,310(5745):96-100
Most people hold beliefs about personality characteristics typical of members of their own and others' cultures. These perceptions of national character may be generalizations from personal experience, stereotypes with a "kernel of truth," or inaccurate stereotypes. We obtained national character ratings of 3989 people from 49 cultures and compared them with the average personality scores of culture members assessed by observer ratings and self-reports. National character ratings were reliable but did not converge with assessed traits. Perceptions of national character thus appear to be unfounded stereotypes that may serve the function of maintaining a national identity. 相似文献
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130.
White fat progenitor cells reside in the adipose vasculature 总被引:1,自引:0,他引:1
Tang W Zeve D Suh JM Bosnakovski D Kyba M Hammer RE Tallquist MD Graff JM 《Science (New York, N.Y.)》2008,322(5901):583-586
White adipose (fat) tissues regulate metabolism, reproduction, and life span. Adipocytes form throughout life, with the most marked expansion of the lineage occurring during the postnatal period. Adipocytes develop in coordination with the vasculature, but the identity and location of white adipocyte progenitor cells in vivo are unknown. We used genetically marked mice to isolate proliferating and renewing adipogenic progenitors. We found that most adipocytes descend from a pool of these proliferating progenitors that are already committed, either prenatally or early in postnatal life. These progenitors reside in the mural cell compartment of the adipose vasculature, but not in the vasculature of other tissues. Thus, the adipose vasculature appears to function as a progenitor niche and may provide signals for adipocyte development. 相似文献