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Members of the tumor necrosis factor receptor (TNFR) family regulate the activation, differentiation, and function of many cell types, including cells of the immune system. TNFR-associated factors (TRAFs) function as adapter molecules controlling signaling pathways triggered by TNFR family members, such as activation of nuclear factor B (NF-B). Despite intensive research, the function of TRAF4 in signaling pathways triggered by TNFR-related proteins remains enigmatic. Intriguingly, our functional studies indicated that TRAF4 augments NF-B activation triggered by glucocorticoid-induced TNFR (GITR), a receptor expressed on T cells, B cells, and macrophages. Further analyses revealed that TRAF4-mediated NF-B activation downstream of GITR depends on a previously mapped TRAF-binding site in the cytoplasmic domain of the receptor and is inhibited by the cytoplasmic protein A20. GITR is thought to inhibit the suppressive function of regulatory T cells (Treg cells) and to promote activation of T cells. Taken together, our studies provide the first indications that TRAF4 elaborates GITR signaling and suggest that TRAF4 can modulate the suppressive functions of Treg cells.Received 20 September 2004; received after revision 8 October 2004; accepted 18 October 2004  相似文献   

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Conclusion Geminus account of lunar motion in chapter 18 of hisIntroductio astronomiae is, in our view, an important contribution to Greco-Latin astronomy because, in attempting to reconstruct arithmetically (the parameters of) the Moon's motion in longitude, he undermines the task astronomers had hitherto set for themselves. This undermining of a commonly acknowledged view of the purpose of astronomy is articulated in a whole new set of questions concerning the nature and place of both observation and mathematical reasoning in the science of the heavens. Yet, one must not overlook the fact thatGeminus reconstruction also indicates resources for addressing these questions. Of these resources, the most powerful proved to be the idea that irregular motion could be quantified as a systematic departure from a mean motion, and the idea that observational data could be organized and structured by means of genetic arithmetical reconstructions.But, since we limit our attention to extant treatises and decline to speculate about works or parts of works that have not survived, we must say that it would takePtolemy to discern the new direction for astronomy thatGeminus opened up and to pursue it. In part, this involved straightening out the conflated conception of mean motion in chapter 18 — the qua arithmetic mean daily displacement can only be anapparent lunar motion in longitude and not one the Moonreally makes, but the same need not be true of the qua periodic mean daily displacement — and determining its proper relation to real and apparent planetary motion. Indeed,Ptolemy's genius lay, we think, in seeing that even though, in assimilating Babylonian astronomy, earlier and contemporary Greco-Latin writers betrayed a confused, inconsistent, and unsophisticated grasp of the proper role of arithmetic, geometry, and observation in astronomical argument [seeBowen 1994], the solution lay in a mathematical reconstruction of the observed celestial motions, in which mean motion played an essential role.  相似文献   

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-Spermophilus brunneus . , 13 18 ,S. brunneus S. townsendii mollis (2n=38) , , ; ;S. brunneus . S. brunneus , Spermophilus.

Supported by National Science Foundation Grants No. GB32114X and No. GB 29131X, and the Sprague Foundation. We thankD. Pozin for technical assistance.  相似文献   

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Citellus (s. str.) relictus, C. dauricus C. pygmaeus (2=36, NF=72). . (Colobotis) erythrogenys . fulvus -. . (Urocitellus) undulatus (2n=32, NF=64) . columbianus. Citellus, , Citellus, . , .  相似文献   

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rII T2L , rII T4B. rII T2L rII T4B. T2L rII T4B.  相似文献   

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- . Ovis musimon (2n=54) O. orientalis (2n=54) - - -O. canadensis mexicana (2n=54) O. musimon x O. canadensis 12 - . 2 27 . - .

Supported by National Science Foundation Grant no. GB 32114X and the Sprague Foundation. We thank Dr. T. C. Hsu for assistance in making the chromosome preparations and for advice and encouragement. The Trustees of the Rachelwood Wildlife Research Preserve generously allowed the biopsy of specimens of their custody. Mr.Arthur Popham kindly provided the specimens from Iran while Dr.R. M. Robinson obtained biopsies from the desert sheep.  相似文献   

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Conclusion (1) The maximal reactions of cerebral resistance vessels arise at the stimulation frequency of 30 cps, the maximal reactions of capacitance vessels at the frequency of 10 cps. (2) Reactions of resistance vessels in the pulmonary lobe increase in the range of stimulation frequencies from 11–50 cps, maximal reactions of pulmonary capacitance vessels are observed at the frequency of 30–40 cps. (3) Reactions of resistance vessels situated below the abdominal aorta bifurcation increase progressively in the range of frequencies from 6–50 cps, the magnitude of capacitance vessel reaction reaching its maximum value at 20 cps.
30 /, — 10 /. 50 /. 30–40 /, 20 /.
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a aaa a aa aa a a E. coli aa, a aa aa a , a a aa - a .

Laboratory of Biological Investigations.

Laboratory for Chemistry of Antibiotics.  相似文献   

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