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51.
Octopus joubini Robson were hatched and reared in a closed circulating sea-water system. Mortality was greatest during the period of hatching. The longest surviving octopus lived for 128 days—it had increased its weight × 5, from 0·04–0·19 g, mantle length × 3, from 3–9 mm, head width × 2, from 3–5 mm. Observations of (1) general behaviour, (2) feeding behaviour, (3) social behaviour of the newly hatched octopuses (0–3 days) and the three longest surviving octopuses (93–119 days) are described. In particular it was observed that the older octopuses would readily grasp and eat small live crabs when these were made to touch the suckers or arms. On no occasion did the attacks appear to be visually elicited. This result is discussed with reference to the memory and learning experiments using O. vulgaris. Possible reasons for the limited survival are also discussed. 相似文献
52.
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54.
Increased free-cystine content of fibroblasts cultured from patients with cystinosis 总被引:3,自引:0,他引:3
Schneider JA Rosenbloom FM Bradley KH Seegmiller JE 《Biochemical and biophysical research communications》1967,29(4):527-531
The presence of a significantly increased content of free-cystine in skin fibroblasts from both homozygotes and heterozygotes for cystinosis emphasizes the central role of cystine in this disease, even though the primary defect responsible for cystine accumulation is yet to be determined. The studies described in this communication provide evidence that cystine is compartmentalized in a subcellular location in cystinotic cells. In fact, the very growth of cystinotic fibroblasts in the presence more than 100 times the usual content of free-cystine is evidence that the accumulated cystine is not freely dispersed throughout the cell, since would otherwise inhibit many enzymes requiring free sulfhydryl groups for activity (Patrick, 1965). We have no evidence as to whether the cystine is located in a known subcellular organelle or in a previously unrecognized location. Skin fibroblasts may provide a convenient tool to pursue these questions. 相似文献
55.
We have examined the nature of the circular dichroism band at 330 mμ for a series of copolymers of β-p-nitrobenzyl L -aspartate with β-benzyl L -aspartate. The circular dichroism band arises from an electronic transition in the nitroaromatic group. In order to interpret the effect quantitatively, we employed a simplified statistical treatment and curve fitting for six copolymers. Both approaches gave consistent results, which indicates that the dichroism comes from pairwise interactions between two nitrobenzyl groups. We constructed a molecular model that meets the constraints and requirements of the analyses developed in this paper. In this model, it is proposed that the main chain forms a right-handed α-helix and that nitrobenzyl groups separated by four residues interact with each other. 相似文献
56.
The ultrastructure of the flagella of three chrysomonads with particular reference to the mastigonemes 总被引:2,自引:0,他引:2
D E Bradley 《Experimental cell research》1966,41(1):162-173
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58.
Olwin BB 《Cytotechnology》1989,2(4):351-365
Heparin-binding growth factors modulate diverse biological activities including cellular proliferation, cellular differentiation, morphogenesis, and angiogenesis. Biochemical characterization for two members of the heparin-binding growth factor family, acidic and basic fibroblast growth factors, is extensive, while characterization of the remaining five members is forthcoming. Cell surface receptors have been identified for acidic and basic fibroblast growth factors, but little is known concerning their sites of action in vivo or the mechanisms involved in transducing the energy of growth factor binding to a biological response. An understanding of the biological basis for the diversity of the heparin binding growth factor family and the in vivo actions of these factors will prove a major challenge to future research efforts. 相似文献
59.
Partners in general practice have to buy any equipment they want themselves. As a result partners in high investing practices have lower net incomes. Of the 297 practices in Devon and Cornwall, 265 responded to a questionnaire listing 115 possible items of practice equipment. Overall, practices seemed to be fairly well equipped. Key findings were that 193 of those who responded had an electrocardiograph, 206 had a kit for minor operations, 119 owned a computer, and less than one third owned a microscope. Most of these practices were high investors. There seems to be a shift away from some traditional instruments towards expensive information technology. Government policies are encouraging the use of computers and such equipment, though funds are not necessarily being made available for this purpose. 相似文献
60.
Bradley C. Hyman 《Journal of nematology》1990,22(1):24-30
Genetic variation within nuclear and mitochondrial DNA of Meloidogyne species and host races has been evaluated for the development of root-knot nematode molecular diagnostics. This review summarizes the distinctive features of several useful DNA-based assays for plant-parasitic nematodes, focusing upon the direct application of these procedures for Meloidogyne detection, identification, and systematics. 相似文献