地理信息影像化在长江上游土壤侵蚀敏感性评价中的应用

应用地理信息影像化方法,从土壤侵蚀的影响因素出发,在ERDAS软件支持下,建立长江上游降雨侵蚀力、地形起伏、土壤可蚀性、植被覆盖信息的专题数字模型。在此基础上,进行综合分析得到土壤侵蚀敏感性指数影像化图,并探讨长江上游土壤侵蚀敏感性空间分异特征。研究表明,评价结果信息客观细致,适用于生态环境的综合评价;长江上游土壤侵蚀敏感性总体水平较高,中度敏感和高度敏感面积占总面积82．8％;长江上游土壤侵蚀敏感性空间分异显著。     

Postnatal development of adrenergic and cholinergic sensitivity in the isolated rat atria

The sensitivity to adrenergic drugs in isolated rat atria increased with the postnatal development. The cholinergic chronotropic sensitivity did not further change after birth.     

Differential sensitivity to ethidium bromide of replicative DNA synthesis and bleomycin-induced unscheduled DNA synthesis in permeable mouse sarcoma cells

Replicative DNA synthesis in permeable mouse sarcoma cells was more sensitive to ethidium bromide (EtBr) than bleomycin-induced unscheduled DNA synthesis (UDS). A similar difference in sensitivity to EtBr was observed between DNA polymerases alpha and beta. The difference in sensitivity to EtBr of replicative DNA synthesis and UDS in the present system seems to reflect mainly the sensitivity difference between DNA polymerases alpha and beta.     

Sensitivity of human lymphocytes to bleomycin increases with age.

The sensitivity of human peripheral blood lymphocytes to bleomycin and mitomycin-C was assessed by measuring the inhibition of phytohemagglutinin stimulated proliferation. The sensitivity to bleomycin, and not to mitomycin-C, increased with the age.     

Change in taste preference related to aging of taste cells in rat

Following the suppression of renewal of rat taste cells by vinblastine sulphate, the preference for sucrose decreased markedly while the aversion to quinine did not change. The results suggest that the sensitivity of taste cells to sucrose decreases with their aging, but the sensitivity to quinine increases.     

Measuring toxicity in marine environments: critical appraisal of three commonly used methods

Toxicity quantification is important in environmental monitoring, in the field of natural products, and in chemical ecology. The sensitivity and precision of three commonly used methods detecting toxicity in marine environments were compared, using the toxic marine spongeCrambe crambe as a test organism. The paper disk diffusion method (run with marine bacteria) showed the least sensitivity and did not permit toxicity levels to be quantified. The sea urchin and the MICROTOX® tests showed greater sensitivity, and the latter had the higher precision. The relative performance of these methods is discussed. It is concluded that the MICROTOX® bioassay displays the best characteristics for toxicity quantification.     

Role of tropomyosin in the sensitivity of (Na+ + K+) ATPase to ouabain]

EDTA treatment of isolated plasma membranes from MF2S cells increased 1,000 fold the sensitivity of (Na+ + K+) ATPase activity to ouabain. The original sensitivity of the enzyme to the drug is recovered after addition of tropomyosin together with Ca++ ions to the treated membranes.     

Der Einfluß der Temperatur des Auges auf die spektrale Empfindlichkeitskurve

Summary The influence of the temperature of the eye on the spectral distribution of its sensitivity was studied. The leading idea was that the small long-wave light quanta could only decompose a molecule of the photochemical substances if this molecule had already a sufficient thermal energy. One must therefore expect the sensitivity for long wavelengths to be higher at high temperatures; moreover this influence of temperature is most pronounced for the longest wavelengths. In the measurements the sensitivity for the wavelengths of 660 mµ and 730 mµ were comparedwith each other. In the accompanying figure the slit width of the apparatus at 660 mµ is shown as a function of temperature. The experimental points are close to the lines which were predicted by the theory.     

Spektrale Phototaxis von Planktonrotatorien

Summary The spectral sensitivity of 3 species of planktonic Rotatoria (Asplanchna priodonta, Polyarthra remata, Filinia longiseta) were measured by means of the positive phototactic reaction.Asplanchna andPolyarthra both have a broad maximum sensitivity range around 540 nm and a near maximum at 440 nm. In the UV direction (to 360 nm) the spectral sensitivity increases. In contrast,Filinia has only a maximum of 460 nm in the visible spectrum, but behaves similarly to the other species in the UV region. The ecological significance of these results is discussed, as well as their bearing on a possible dermal light sense.     

Vision in the ultraviolet

Sensitivity to ultraviolet light (UV) is achieved by photoreceptors in the eye that contain a class of visual pigments maximally sensitive to light at wavelengths <400 nm. It is widespread in the animal kingdom where it is used for mate choice, communication and foraging for food. UV sensitivity is not, however, a constant feature of the visual system, and in many vertebrate species, the UV-sensitive (UVS) pigment is replaced by a violet-sensitive (VS) pigment with maximal sensitivity between 410 and 435 nm. The role of protonation of the Schiff base-chromophore linkage and the mechanism for tuning of pigments into the UV is discussed in detail. Amino acid sequence analysis of vertebrate VS/UVS pigments indicates that the ancestral pigment was UVS, with loss of UV sensitivity occurring separately in mammals, amphibia and birds, and subsequently regained by a single amino acid substitution in certain bird species. In contrast, no loss of UV sensitivity has occurred in the UVS pigments of insects.     

Sensitivity of human lymphocytes to bleomycin increases with age

Summary The sensitivity of human peripheral blood lymphocytes to bleomycin and mitomycin-C was assessed by measuring the inhibition of phytohemagglutinin stimulated proliferation. The sensitivity to bleomycin, and not to mitomycin-C, increased with the age.We thank Miss L. Bailey for excellent technical assistance and the Bristol-Myers Company for supply of bleomycin. This work was supported by the National Health and Medical Research Council of Australia and the Anti-Cancer Council of Adelaide University, South Australia.     

Differential sensitivity to photohemolysis of erythrocytes enriched with some liposome-carried substances

The sensitivity of human erythrocytes to photohemolysis sensitized by addition of protoporphyrin IX can be selectively affected by their enrichment with substances carried by cationic liposomes. In particular the enrichment which superoxide dismutase is accompanied by a copper-related greater sensitivity toward photohemolysis, as observed in the Down's syndrome (mongolism). Instead it is possible to protect the erythrocytes against the phototoxic effect of protoporphyrin by enrichment with small amounts of beta-carotene.     

Action of cadmium on a free dinoflagellate Prorocentrum micans E: growth, cadmium absorption and cell modifications]

The study of the growth of Prorocentrum micans E. submitted to sublethal doses of cadmium demonstrated a high sensitivity of this Dinoflagellate to the polluant starting with concentration of 5 microgram/l. The uptake of cadmium was measured by pulse polarographic analysis of the filtered culture medium. Structural modifications, not apparent in living cells, are visible after fixation. The high sensitivity of Prorocentrum micans to cadmium, also its easy culture, makes it a suitable pollution indicator of this heavy metal.     

Genetic and pharmacological models of cholinergic supersensitivity and affective disorders

Increased muscarinic sensitivity has been associated with altered hormonal states (hypothyroidism and hyperadrenocorticism), chronic administration of muscarinic antagonists or antidepressants with muscarinic actions, selective breeding for anticholinesterase sensitivity, and certain inbred strains of rats and mice. Thus, both genetic and environmental factors may influence muscarinic receptor sensitivity. The reasonably detailed studies on the selectively-bred rats have revealed that the Flinders Sensitive Line (FSL) rats weigh less, are less active, are more sensitive to muscarinic agonists and to stressors, and have higher concentrations of hippocampal and striatal muscarinic receptors than 'normal', or the selectively-bred, Flinders Resistant Line (FRL) rats. Thus, there are a number of parallels between FSL rats and depressed humans. The FSL rats may be the first animal model of depression to mimic the actual trait of depression, and not just the state.     

生物大分子的化学发光成像研究

本文介绍了三种化学发光成像法在人血清结合珠蛋白分型电泳的快速检测方面的应用。这三种方法都是基于鲁米诺一过氧化氢发光体系。使用免疫化学发光成像法，直接化学发光成像法和增强化学发光成像法，能够提高对结合珠蛋白检测的灵敏度，获得更宽的线性范围。我们使用这三种方法完成了对结合珠蛋白的快速、高灵敏、高选择性的检测。     

Differential sensitivity of pinna reflex and esophageal temperature to clonidine in mice depleted of central noradrenaline by DSP-4

Mice injected with DSP-4 [N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine], a selective noradrenergic neurotoxin, had marked depletions of central noradrenaline and an attenuated post-decapitation reflex. DSP-4-treated mice exhibited an increased sensitivity to the alpha 2-adrenoceptor agonist clonidine as measured by inhibition of the pinna reflex, but normal sensitivity as measured by hypothermia. This differential sensitivity may reflect the presence of supersensitive postsynaptic alpha 2-adrenoceptors in some, but not all, CNS regions after DSP-4 treatment.     

Differential sensitivity to tributyltin of cytochrome-containing and cytochrome-deficient cells of Escherichia coli SASX76

The effect of tributyltin (TBT) chloride on the growth of cytochrome-deficient and cytochrome-containing cells of Escherichia coli SASX76 was examined. The former cells were found to be at least 20 times more sensitive to TBT. It is proposed that the differential sensitivity of these two cell types to the biocide, TBT, may be due to a different mode of energy generation by cytochrome-deficient and cytochrome-sufficient cells. In addition to the energy state, the pH change caused by the presence and absence of cytochromes which occurred during growth also resulted in a differential sensitivity of these cells.     

Does the long term wear of contact lenses produce a loss of corneal sensitivity?

Summary Corneal sensitivity was measured with the Cochet-Bonnet aesthesiometer in a control group of 42 people and in 82 people who had worn hard contact lenses for various amounts of years. Corneal sensitivity was found to diminish significantly after a few years of wear, thus placing the wearer at some risk.     

17 Beta-estradiol-sensitivity of cultured myometrial cells

The estrogen sensitivity of cells cultured from the rat myometrium was studied by growing the cells in the absence or presence of 1 nM 17 beta-estradiol. Following a time lag of approximately 10 days, exposure to estrogen resulted in increased incorporation of radiothymidine by the cells. Estrogen treatment also decreased isoproterenol-dependent and GTP-dependent adenylate cyclase activity, but had no effect on basal activity. These cultured cells have been shown previously to have some properties of uterine smooth muscle. The effects estrogen has in vitro, therefore, may reflect important properties in vivo that account for the mechanism by which the sex steroid decreases the sensitivity of the myometrium to isoproterenol.     

Baroreceptor reflex sensitivity after acute blood volume expansion in anesthetized dogs

Summary Changes in heart rate resulting from mechanically induced changes in arterial blood pressure were used as a measure of baroreflex sensitivity. This sensitivity was shown to be decreased after volume expansion.This work was supported in part by PHS grant HL-23239 and a grant from the Central Ohio Heart Chapter of the American Heart Association.