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61.
Listed are 121 species of Scolytidae from Oregon. Ten species are reported from Oregon for the first time: Hylastes tenuis Eichhoff, Phloeosinus scopulorum scopulorum Swaine, Phloeosinus hoferi Blackman, Trypodendron betulae Swaine, Xyleborus xylographus (Say), Trypophloeus striatulus (Mannerheim), T. Thatcheri Wood, Procryphalus mucronatus (LeConte), Pityophthorus scalptor Blackman, and Monarthrum dentigerum (LeConte). The second Oregon specimen of an exotic species, Xyleborus californicus Wood, is reported also. 相似文献
62.
Eighteen species of Scolytidae are reported from Washington state for the first time or raised from obscurity: Scierus annectens LeConte, Hylesinus californicus (Swaine), Phloeotribus lecontei Schedl, Carphoborus vandykei Bruck, Polygraphus rufipennis (Kirby), Crypturgus borealis Swaine, Pityogenes knechteli Swaine, Ips mexicanus (Hopkins), Ips perturbatus (Eichhoff), Ips plastographus plastographus (LeConte), Ips woodi Thatcher, Trypodendron betulae Swaine, Trypophloeus striatulus (Mannerheim), Procryphalus mucronatus (LeConte), Procryphalus utahensis Hopkins, Pseudopityophthorus pubipennis (LeConte), Pityophthorus alpinensis G. Hopping, and Pityophthorus grandis Blackman. Host tree and collection data are given for these species. A total of 105 scolytid species known from Washington are listed. 相似文献
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The giant cells (multinucleate macrophages) of human sarcoidosis have been shown by the unlabelled antibody immunoperoxidase technique at electron microscope level to contain lysozyme within cytoplasmic granules. 相似文献
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Volatile content of lunar volcanic glasses and the presence of water in the Moon's interior 总被引:1,自引:0,他引:1
The Moon is generally thought to have formed and evolved through a single or a series of catastrophic heating events, during which most of the highly volatile elements were lost. Hydrogen, being the lightest element, is believed to have been completely lost during this period. Here we make use of considerable advances in secondary ion mass spectrometry to obtain improved limits on the indigenous volatile (CO(2), H(2)O, F, S and Cl) contents of the most primitive basalts in the Moon-the lunar volcanic glasses. Although the pre-eruptive water content of the lunar volcanic glasses cannot be precisely constrained, numerical modelling of diffusive degassing of the very-low-Ti glasses provides a best estimate of 745 p.p.m. water, with a minimum of 260 p.p.m. at the 95 per cent confidence level. Our results indicate that, contrary to prevailing ideas, the bulk Moon might not be entirely depleted in highly volatile elements, including water. Thus, the presence of water must be considered in models constraining the Moon's formation and its thermal and chemical evolution. 相似文献
65.
Although massive stars (commonly defined as those in excess of about eight solar masses, or with initial luminosities of a thousand times the solar luminosity or more) have an enormous impact on the galactic environment, how they form has been a mystery. The solution probably involves the existence of accretion disks. Rotational motions have been found in the gas surrounding young high-mass stars, which suggests that non-spherical accretion could be the fundamental ingredient of the massive-star formation recipe. 相似文献
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Vertebrate HoxA and HoxD cluster genes are required for proper limb development. However, early lethality, compensation and redundancy have made a full assessment of their function difficult. Here we describe mice that are lacking all Hoxa and Hoxd functions in their forelimbs. We show that such limbs are arrested early in their developmental patterning and display severe truncations of distal elements, partly owing to the absence of Sonic hedgehog expression. These results indicate that the evolutionary recruitment of Hox gene function into growing appendages might have been crucial in implementing hedgehog signalling, subsequently leading to the distal extension of tetrapod appendages. Accordingly, these mutant limbs may be reminiscent of an ancestral trunk extension, related to that proposed for arthropods. 相似文献
70.
It has recently been established that both acute human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections are accompanied by a dramatic and selective loss of memory CD4+ T cells predominantly from the mucosal surfaces. The mechanism underlying this depletion of memory CD4+ T cells (that is, T-helper cells specific to previously encountered pathogens) has not been defined. Using highly sensitive, quantitative polymerase chain reaction together with precise sorting of different subsets of CD4+ T cells in various tissues, we show that this loss is explained by a massive infection of memory CD4+ T cells by the virus. Specifically, 30-60% of CD4+ memory T cells throughout the body are infected by SIV at the peak of infection, and most of these infected cells disappear within four days. Furthermore, our data demonstrate that the depletion of memory CD4+ T cells occurs to a similar extent in all tissues. As a consequence, over one-half of all memory CD4+ T cells in SIV-infected macaques are destroyed directly by viral infection during the acute phase-an insult that certainly heralds subsequent immunodeficiency. Our findings point to the importance of reducing the cell-associated viral load during acute infection through therapeutic or vaccination strategies. 相似文献