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1.
Shallow-water vegetated estuarine habitats, notably seagrass, mangrove and saltmarsh, are known to be important habitats for
many species of small or juvenile fish in temperate Australia. However, the movement of fish between these habitats is poorly
understood, and yet critical to the management of the estuarine fisheries resource. We installed a series of buoyant pop nets
in adjacent stands of seagrass, mangrove and saltmarsh in order to determine how relative abundance of fishes varied through
lunar cycles. Nets were released in all habitats at the peak of the monthly spring tide for 12 months, and in the seagrass
habitat at the peak of the neap tide also. The assemblage of fish in each habitat differed during the spring tides. The seagrass
assemblage differed between spring and neap tide, with the neap tide assemblage showing greater abundances of fish, particularly
those species which visited the adjacent habitats when inundated during spring tides. The result supports the hypothesis that
fish move from the seagrass to the adjacent mangrove and saltmarsh during spring tides, taking advantage of high abundances
of zooplankton, and use seagrass as a refuge during lower tides. The restoration and preservation of mangrove and saltmarsh
utility as fish habitat may in some situations be linked to the proximity of available seagrass. 相似文献
2.
3.
A Guha 《Journal of molecular biology》1971,56(1):53-62
4.
B Mukherji A Guha R Loomis M T Ergin 《Journal of immunology (Baltimore, Md. : 1950)》1987,138(6):1987-1991
The cytotoxic host immune response toward autologous human cancer may be regulated by the immunoregulatory network. Here we show that helper T cells, cloned from peripheral blood lymphocytes that were sensitized in vitro against an autologous human malignant paraganglioma, proliferated against and made interleukin 2 when cocultured with the tumor-associated antigen in the presence of autologous accessory cells. Furthermore, the helper cell clones amplified cytotoxic immune response by peripheral blood lymphocytes against the paraganglioma cells in coculture with the blood lymphocytes and the paraganglioma cells. An autologous T cell line bearing suppressor phenotype, established from a lymph node that had been infiltrated with the paraganglioma tumor cells, in contrast to the helper cells, selectively suppressed the cytotoxic immune response by the blood lymphocytes against the paraganglioma cells in identical coculture. These results, therefore, demonstrate the existence of cell-mediated immunologic regulations of the cytotoxic immune response (concurrent amplification and suppression in the same host) against an autologous human tumor. 相似文献
5.
The effect of cellulosic substrates on the production of extra-cellular cellulases and their cellulolytic activity inChaetomium globosum has been studied in shake flask cultures. Production of endoglucanase, exoglucanase and filter paper cellulase was highest with pure cellulose whereas -glucosidase was maximally induced by wheat straw. A suitable pretreatment for wheat straw was peracetic acid followed by NaOH and that of bagasse with NaOH for saccharification.
Résumé On a étudié l'effet de substrats cellulosiques sur la production de cellulases extracellulaires et leur activité cellulolytique chezChaetomium globosum en culture en flacons agités. La production d'endoglucanase, d'exoglucanase et de cellulase type papier-filtre est maximum avec la cellulose pure tandis que la -glucosidase est induite de manière maximum par la paille de froment. La paille de froment est traitée de manière adéquate pour la saccharification par l'acide peracétique suivi de NaOH, la bagasse, par NaOH.相似文献
6.
Cytogenetic effects in a group of traffic policemen in Cairo 总被引:3,自引:0,他引:3
The aim of this study was to evaluate the cytogenetic effects in humans exposed to automobile exhaust. The induction of chromosome damage was studied in an exposed group of 28 traffic policemen with exposure of over 10 years and a control group of 15 policemen trainers from the Faculty of Police. The percentage of chromosomal aberrations as well as the mean sister-chromatid exchanges were significantly higher among the traffic policemen than in the control group. The cause for this elevated chromosome damage is most likely due to their exposure to pollutants from automobile exhaust, however, the increase is not correlated with the blood lead level or the duration of employment. On the other hand, the increase in chromosome damage among the traffic policemen is enhanced further by smoking. 相似文献
7.
A rapid, one-step procedure has been developed for inducing direct organogenesis and somatic embryogenesis in cultures of Phaseolus coccineus L., P. acutifolius A., P. aureus L. [Vigna radiata L. Wilczek] and P. wrightii L. Development of somatic embryos and shoot buds occurred within 6–8 weeks of culture from intact seedlings raised on MS (Murashige and Skoog 1962) medium supplemented with N6-benzylaminopurine (BAP). Shoot buds or embryoids originated from subepidermal tissue of the regions adjacent to the shoot apex, hypocotyl and cotyledonary axils. While P. acutifolius and P. aureus were regenerated via shoot formation and P. wrightii by somatic embryogenesis, both embryogenesis and shoot regeneration were observed in P. coccineus. Relatively higher levels of BAP, 50–80 M, were found to be optimal for inducing regeneration while lower concentrations were ineffective. About 40–70 shoots and 70–250 somatic embryos were produced per responding seedling. Regenerated shoots and somatic embryos developed into whole plants on a basal medium or the one supplemented with 1 M naphthaleneacetic acid. 相似文献
8.
Several investigations have been made for the heat flow problems in skin and subdermal tissues under normal physiological
and atmospheric conditions. This paper considers the existence of a malignant tumour in the underlying tissues of epidermis
of a human body. The surrounding tissues are assumed to have normal physiological functions, namely self-controlled metabolic
activity, variable blood flow and perspiration. For the malignant portion the metabolic activity is taken to be continuous
and uncontrolled. The effect of this factor is studied on the temperature profiles of the skin. 相似文献
9.
B Mukherji S A Wilhelm A Guha M T Ergin 《Journal of immunology (Baltimore, Md. : 1950)》1986,136(5):1888-1892
The potential existence of down-regulation of cytotoxic immune response against an autologous human melanoma line was investigated as a possible explanation for cytotoxic unresponsiveness against the autologous melanoma cells. The melanoma cell line, PJ-M, was established and lymph node resident lymphocytes (LNL) were isolated from a lymph node which was partially infiltrated with the melanoma cells. Autologous peripheral blood lymphocytes (PBL) were sensitized in in vitro co-culture (IVC) against radiated PJ-M cells in the presence or absence of PJ-M-sensitized LNL and enriched suppressor (OKT8+) or inducer (OKT4+) LNL populations, and were assayed for cytotoxicity in a 4-hr 51Cr-release microcytotoxicity assay. Significant cytotoxic response against PJ-M could be generated in the PBL, but not in the LNL. The addition of sensitized, unfractionated LNL, OKT8+, or OKT4+ LNL populations abrogated cytotoxic response in the PBL against PJ-M. The suppression of cytotoxic response was induced selectively against the PJ-M targets, because IVC of PBL in the presence of the sensitized LNL did not affect the generation of polyclonal cytotoxic alloreactivities, nor did they abrogate the generation of cytotoxic response against allogeneic targets in IVC against the corresponding allogeneic targets. These results suggest the possibility that cytotoxic immune response against the autologous melanoma cells might have been suppressed by the individual's own immunoregulatory circuit. 相似文献
10.
Platelet serotonin (5-HT) content and uptake were studied in male SHR and WKY at various ages. Blood was withdrawn from the carotid artery under anesthesia and 5-HT levels determined from platelet rich plasma (PRP) using a HPLC technique coupled with an electrochemical detection method. Platelet 5-HT uptake was studied by incubating PRP at 37 degrees C for 10 sec with increasing concentrations of 3H-5HT. Lineweaver- Burk plots of 3H-5HT uptake were linear suggesting simple Michaelis- Menten uptake kinetics. The SHR had more platelets than age-matched controls and consequently a higher blood circulating pool of 5-HT. Nevertheless, the 5-HT platelet levels were similar to those of their age-matched rats. The 5 week-old SHR and WKY had greater numbers of platelets and higher 5-HT platelet levels than the older rats of both strains. The affinity constants (Km) and the maximal velocities (Vmax) of platelet 5-HT uptake did not differ significantly between the 12 week- and the 6 month-old SHR and WKY. These data suggest that the SHR do not show the same impairment in platelet 5-HT metabolism as observed in essential hypertension in man. 相似文献