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811.
Marluce Bibbo Peter H. Bartels Harvey E. Dytch James H. Puls Frederick T. Pishotta George L. Wied 《Cell biochemistry and biophysics》1983,5(1):61-69
Comparison was made between cytophotometric measurements obtained using two data acquisition systems, one a microphotometer
and the other a rapid video camera system, to ascertain whether the degradation of data with the faster video acquisition
system still results in recorded images of sufficient quality to permit computer discrimination between cells of very similar
appearance. Normal-appearing intermediate cells from cases with normal cytology and those from patients with dysplasia or
malignant disease, as well as the subvisual markers within these cells that have rendered them capable of cytophotometric
discrimination, were used for the study. Comparison of the data recorded by the two systems indicates that the diagnostic
information is preserved in the change-over to a full-field, video-rate scanning system, with differences in the data caused
primarily by differences in the spectral response of the two systems. This was reflected in the substantial differences observed
in the color-related features and the lesser differences seen in the textural features, while the morphometric features (outline
and shape) were virtually unaffected. The differences were primarily expressed on a cell-to-cell basis; in sets of about 300
cells, which would be used in patient-to-patient comparisons, the feature values showed remarkable consistency between the
two systems. 相似文献
812.
Maikottia属骨骼微细构造及其分类 总被引:1,自引:1,他引:0
Maikottia Laurusevich,1967属是泡沫珊瑚目中较特殊的类型,呈多角块状复体。经电镜研究表明,其骨骼微细构造以晶片型层状骨骼为主,隔壁刺由复式杆晶榍组成,层状骨骼包绕隔壁刺,在隔壁刺内包绕和联结单杆晶榍。体壁和横板均由层状骨骼组成。本属的纤状骨骼属较原始简单类型-晶粒和短轴晶柱,它组成复式杆晶榍内单杆晶榍的轴带,并呈分散状排列。根据该属为泡沫珊瑚类型隔壁及复式杆晶榍,将其归入泡 相似文献
813.
Catherine Serres Xavier Montagutelli Reiner A. Veitia Daniel Vaiman 《BioEssays : news and reviews in molecular, cellular and developmental biology》2010,32(2):132-142
Positional cloning of the quantitative trait locus (QTL) still encounters numerous difficulties, which explains why thousands of QTL have been mapped, while only a few have been identified at the molecular level. Here, we focus on a specific mapping tool that exists in plant and animal model species: interspecific recombinant congenic strains (IRCSs) or interspecific nearly isogenic lines (NILs). Such panels exhibit a much higher sequence diversity than intraspecific sets, thus enhancing the contrasts between phenotypes. In animals, it allows statistical significance to be reached even when using a limited number of individuals. Therefore, we argue that interspecific resources may constitute a major genetic tool for positional cloning and for understanding some bases of speciation mechanisms. 相似文献
814.
Carolyn M. Crockett 《American journal of primatology》1984,6(2):121-122
This study examines the positional and activity behavior of a captive slow loris, Nycticebus coucang. The male individual was housed in a primate facility providing a seminatural environment and was subjected to a series of videotape recordings from which 1,878 point observations were taken. The enclosure was designed to allow maximum flexibility of substrate use. Quantitative information detailing activity, positional mode, and substrate geometry was collected using a checklist of 15 variables. Data were tabulated and compared as frequency distributions to describe activity budgets, the use of locomotor and postural modes, and the relation of posture to activity behavior and substrate geometry. The results indicated that almost 90% of the active day may be devoted to behaviors directly or indirectly related to dietary functions. For locomotor behavior, both climbing and walking were associated with the use of diagonal couplets. The loris devoted 52% of its positional behavior to postural modes, favoring the quadrupedal stand, triplets, and sitting. Suspension was found to be used more often in posture than locomotion. Overall, the loris's repertory of positional modes accommodated a wide range of substrate geometries. 相似文献
815.
K. ARORA J. GRACE F. STEWART 《Botanical journal of the Linnean Society. Linnean Society of London》1982,85(3):169-177
Leaf surfaces of the native Heracleum sphondylium, the alien Heracleum mantegazzianum and the interspecific hybrid were examined using SEM and light microscopy. The surfaces differed in hairiness, especially in the length of the hairs, although the hairs did not differ in general form, or distribution on the leaf surface. Stomata differed little in length, width or frequency, but there were differences in the sort of stomata in relation to the surrounding epidermal cells. The hybrid material was intermediate between the parental species, and sometimes displayed aberrant trichomes that were contorted in contiguous pairs. The results are discussed in relation to other work on the epidermal features of the Umbelliferae: as a means of discriminating the three taxa, and in relation to the ecological distributions of the species. 相似文献
816.
S. Bellezza G. Paradossi R. De Philippis P. Albertano 《Journal of applied phycology》2003,15(2-3):193-200
Two strains of Leptolyngbya isolated from Roman hypogea were studied in order to characterise the ultrastructural features of the sheath and its composition in exopolysaccharides. Cytochemical stains used in light and transmission electron microscopy allowed detection of the presence of carboxylic groups within the sheath, composed by two different layers. The composition in monosaccharides of three fractions (released, hot and cold capsular polysaccharides) extracted from cultures was determined by reverse phase-high performance liquid chromatography, while the behaviour of the fractions at various pH values was studied by using the circular dichroism. The cytochemical and physico-chemical characterisation of exopolysaccharides should help both the conservation of lithic surfaces of artistic interest and the taxonomic identification of Leptolyngbya strains. 相似文献
817.
818.
Sebastian M. Frank Susanne Bründl Ulrike I. Frank Yuka Sasaki Mark W. Greenlee Takeo Watanabe 《Current biology : CB》2021,31(2):427-432.e5
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819.
BackgroundA high incidence of benign paroxysmal positional vertigo (BPPV) is reported in postmenopausal women, and the association between estradiol (E2) deficiency and the occurrence of BPPV was investigated.MethodsPostmenopausal women with and without BPPV were included from 2016 to 2019, and 1-year follow-up was performed. Serum otolin-1 and E2 levels were assayed before the canalith repositioning treatment. Bone mineral density (BMD) was measured with a dual-energy x-ray absorptiometry scan. Receiver operating characteristic analysis was performed to determine the occurrence of BPPV, and Pearson analysis was performed to indicate the correlation between E2, otolin-1, and BMD.ResultsEighty-six postmenopausal women with BPPV and 80 age-, demographics-, and clinical characteristics-matched normal postmenopausal women were enrolled. Decreased E2 levels, increased otolin-1 levels, and decreased BMD were observed in postmenopausal women with BPPV, and increased BMD and decreased otolin-1 levels were observed in patients with higher levels of serum E2. Receiver operating characteristic analysis revealed that E2, otolin-1, and BMD showed low sensitivity and moderate specificity to determine the occurrence of BPPV. On the other hand, a low correlation coefficient was found between E2 and otolin-1, or BMD. It is worth noting that low E2 levels were found in the relapsed patients with BPPV after a 1-year follow-up.ConclusionE2 deficiency is correlated with the occurrence of BPPV, which may be a potential risk biomarker for postmenopausal women. 相似文献
820.
Kristi L. Lewton 《American journal of physical anthropology》2015,156(4):511-530
Identification of positional behavior adaptation in the pelvis of primates is complicated by possible confounding effects of body size and phylogeny. Previous work on primate pelvic allometry has focused primarily on sexual dimorphism and its relationship to obstetric constraints in species with large fetal size relative to maternal size. This study investigates patterns of pelvic scaling with a specific aim to understand how pelvic scaling relates to locomotor function. Patterns of scaling of nine pelvic dimensions were examined in a broad comparative sample of 40 species of primates, covering both haplorhines and strepsirrhines, while accounting for phylogenetic nonindependence. Phylogenetic reduced major axis regressions on pelvic scaling patterns suggest that primate-wide patterns are reflected in haplorhine- and strepsirrhine-specific analyses. Many measures scale isometrically with pelvis size, but notably, features of the ilium tend to scale allometrically. As predicted, ilium width and lower ilium cross-sectional area scale with positive allometry, while lower iliac height scales with negative allometry. Further regression analyses by locomotor group suggest that these ilium measures, as well as pubic symphysis and ischium lengths, differ in their scaling patterns according to locomotor mode. These results suggest that scaling differences within primates, when present, are related to functional differences in locomotor behavior and mechanics. This study supports recent work that identifies adaptations to locomotor loading in the ilium and highlights the need for a better understanding of the relationship between pelvic structural mechanics and the mechanical requirements of primate locomotion. Am J Phys Anthropol 156:511–530, 2015. © 2015 Wiley Periodicals, Inc. 相似文献