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1.
Summary Contrary to Srdi and Gloor's report, we find crystal cells (cc) in the lymph glands ofD. melanogaster larvae; the size and number of inclusions in the cc cannot be used to distinguish the 2 sibling species,D. melanogaster andD. simulans; cc in the hemocoel are not phagocytic cells; the surface properties of the lamellocytes are consistent with their derivation from plasmatocytes and not cc.Supported by grant No. CA16619 awarded by the National Cancer Institute, DHEW, USPHS. 相似文献
2.
C. Rose Broome 《西北部美国博物学家》2011,41(2)
An expression of Centaurium namophilum (Gentianaceae), long confused with C. exaltatum in the Great Basin of the western United States, is described and designated as var. nevadense. It may be separated from the Death Valley region endemic, var. namophilum, by its broader leaves, its diffuse corymbose cyme, the ultimate peduncles that are longer than the flowers, its medium to deep rose pink corolla, and its stamens that equal or exceed the style and are only slightly exserted from the corolla-tube. The var. nevadense occurs from eastern California to western Utah, and from southeastern Oregon and adjacent Idaho south to the northern Mojave Desert of southeastern California. Centaurium exaltatum may be distinguished from the new variety by its broader, more elliptical leaves, dichotomous peduncles, paler pink or bluish and generally four-merous flowers, shorter and more blunt corolla lobes, and a thicker, more included style and stigma. 相似文献
3.
New Sivapithecus humeri from Pakistan and the relationship of Sivapithecus and Pongo 总被引:2,自引:0,他引:2
New humeri of two species of the Miocene hominoid Sivapithecus are described from near Chinji in Pakistan from between approximately 9 and 11 Myr ago. Sivapithecus, a middle and late Miocene hominoid from Turkey and Indo-Pakistan, is overall unlike any living hominoid, although facial-palatal similarities to the extant orangoutan, Pongo, have been used to support a hypothesis of close relationship. Living hominoids have postcranial similarities assumed to be shared derived, among them features of the proximal humerus. However, the new Sivapithecus proximal humeri differ from those of living hominoids, supporting an alternative hypothesis in which Sivapithecus and Pongo are not closely related. It is not clear how to choose between these incompatible hypotheses. 相似文献
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Glycine: a new anti-inflammatory immunonutrient 总被引:7,自引:0,他引:7
7.
Résumé On a mis en évidence chez le Rat une formation de méthylhistamine-3H par décarboxylation de lal-3-méthylhistidine-3H. Cette réaction se produit in vitro et in vivo dans des tissus riches en histidine décarboxylase et elle est prévenue par un inhibiteur de cette enzyme. Les implications biologiques de l'existence de cette nouvelle voie métabolique sont envisagées. 相似文献
8.
Long alpha-helical coiled-coil proteins are involved in a variety of organizational and regulatory processes in eukaryotic cells. They provide cables and networks in the cyto- and nucleoskeleton, molecular scaffolds that organize membrane systems, motors, levers, rotating arms and possibly springs. A growing number of human diseases are found to be caused by mutations in long coiled-coil proteins. This review summarizes our current understanding of the multifaceted group of long coiled-coil proteins in the cytoskeleton, nucleus, Golgi and cell division apparatus. The biophysical features of coiled-coil domains provide first clues toward their contribution to the diverse protein functions and promise potential future applications in the area of nanotechnology. Combining the power of fully sequenced genomes and structure prediction algorithms, it is now possible to comprehensively summarize and compare the complete inventory of coiled-coil proteins of different organisms.Received 27 January 2004; received after revision 23 February 2004; accepted 10 March 2004 相似文献
9.
Genome sequence of enterohaemorrhagic Escherichia coli O157:H7 总被引:31,自引:0,他引:31
Perna NT Plunkett G Burland V Mau B Glasner JD Rose DJ Mayhew GF Evans PS Gregor J Kirkpatrick HA Pósfai G Hackett J Klink S Boutin A Shao Y Miller L Grotbeck EJ Davis NW Lim A Dimalanta ET Potamousis KD Apodaca J Anantharaman TS Lin J Yen G Schwartz DC Welch RA Blattner FR 《Nature》2001,409(6819):529-533
The bacterium Escherichia coli O157:H7 is a worldwide threat to public health and has been implicated in many outbreaks of haemorrhagic colitis, some of which included fatalities caused by haemolytic uraemic syndrome. Close to 75,000 cases of O157:H7 infection are now estimated to occur annually in the United States. The severity of disease, the lack of effective treatment and the potential for large-scale outbreaks from contaminated food supplies have propelled intensive research on the pathogenesis and detection of E. coli O157:H7 (ref. 4). Here we have sequenced the genome of E. coli O157:H7 to identify candidate genes responsible for pathogenesis, to develop better methods of strain detection and to advance our understanding of the evolution of E. coli, through comparison with the genome of the non-pathogenic laboratory strain E. coli K-12 (ref. 5). We find that lateral gene transfer is far more extensive than previously anticipated. In fact, 1,387 new genes encoded in strain-specific clusters of diverse sizes were found in O157:H7. These include candidate virulence factors, alternative metabolic capacities, several prophages and other new functions--all of which could be targets for surveillance. 相似文献
10.
This paper reports a case study where soft systems methodology (SSM) was used to help automate a largely manual administrative (examination) information system in a Pakistani university. Various design suggestions for information system improvements, both administrative and IT-supported were made (and implemented) through comparison with another university in Denmark which is well supported by computer systems. An action design research approach with an interpretative epistemology/ontology was adopted. Though the single comparison experience is difficult to generalise, we conclude that SSM (with some adaptations) can enable a socio-technical comparison and design effort and offer a prototype process. The comparison stimulates forward-looking design, but great care must be taken to accommodate cultural differences, and further research is necessary to integrate more sophisticated cultural analysis tools into the design process. The research extends SSM in information system development??from a single situational analysis to a comparative process and can be adapted as a pattern for practitioners with similar automation needs. 相似文献