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1.
R J Ballou  M T Tseng 《In vitro》1983,19(11):805-806
A modification of an established procedure for autoradiographic processing of cultured cells is described. This method eliminates the need for pipetting each individual well and also for cutting and dismantling the multiwell plate for slide preparation. In this procedure the entire plate can be processed as a single unit and the cells can be analyzed in situ, thus eliminating the time consuming pipetting and cutting procedures. Furthermore, the entire experiment can be filed without use of additional slides or storage boxes. Hence, this is a simpler, time conserving, and economical way to process large numbers of cultures for thymidine labeling indices.  相似文献   

2.
Thermal imaging is a potential tool for estimating plant temperature, which can be used as an indicator of stomatal closure and water deficit stress. In this study, a new method for processing and analysing thermal images was developed. By using remote sensing software, the information from thermal and visible images was combined, the images were classified to identify leaf area and sunlit and shaded parts of the canopy, and the temperature statistics for specific canopy components were calculated. The method was applied to data from a greenhouse water-stress experiment of Vicia faba L. and to field data for Vitis vinifera L. Vaseline-covered and water-sprayed plants were used as dry and wet references, respectively, and two thermal indices, based on temperature differences between the canopy and reference surfaces, were calculated for single Vicia faba plants. The thermal indices were compared with measured stomatal conductance. The temperature distributions of sunlit and shaded leaf area of Vitis vinifera canopies from natural rainfall and irrigation treatments were compared. The present method provides two major improvements compared with earlier methods for calculating thermal indices. First, it allows more accurate estimation of the indices, which are consequently more closely related to stomatal conductance. Second, it gives more accurate estimates of the temperature distribution of the shaded and sunlit parts of canopy, and, unlike the earlier methods, makes it possible to quantify the relationship between temperature variation and stomatal conductance.  相似文献   

3.
4.
通过盆栽试验,用刺槐根瘤菌(Rhizobium of Robinia pseudoacacia)与纤维素分解菌(Cellulose-decomposing Bacteria)对高粱和上海青进行单独接种和混合接种,采用针刺、浸种和涂叶3种接种方法,测量其各种生长指标。初步探究刺槐根瘤菌与纤维素分解菌联合对禾本科作物高粱和双子叶作物上海青两种非豆科植物的促生效应。结果表明,在非针刺条件下,两种菌混接组(B组)比单独接种根瘤菌组(D组)的促生效应更显著,上海青B组在灭菌条件下的根长促生率比D组高出48.97%,高粱B组在非灭菌条件下干重的促生率比D组高出30.76%;而且除了高粱的B组干重以外,盆栽试验条件下,B、D两组的其他生长指标在灭菌情况下的促生率比非灭菌条件下的促生率高,差别最大的为上海青B组鲜重,灭菌条件下比非灭菌条件下高出47.13%。根瘤菌与纤维素分解菌混合接种非针刺组,对高粱和上海青的各项生长指标促生效应明显,可为今后进一步开发非豆科作物菌肥提供试验依据。  相似文献   

5.
The literature is reviewed to summarize the major indices of interspecific competition used in De Wit replacement experiments. Of the many indices that have been defined, some are less than clear as to their meaning, so interpretations are often difficult to make. In an effort to explore the performance of individual indices and to permit cross-correlation among indices, a series of hypothetical results in different competition scenarios is created. A standardized notation for all indices is also provided, along with equations and proofs. Nine indices are reviewed and analyzed for their behavior under the hypothetical scenarios and a new index that provides increased clarification and interpretability over other indices is proposed. Relative Yield Total, Aggressivity, and Relative Replacement Rate were shown to be poor measures of competition. Relative Crowding Coefficient has many restrictions to its use. The clearest index that includes two or more species is Relative Yield of Mixture. Indices that describe single species accurately were found to be Relative Yield (RY) and Relative Competition Intensity (RCI), both of which are mathematically convertible. An index introduced here, Change in Contribution (CC), is a single species index that differs from RY and RCI because it takes into account the overall biomass each species contributes.  相似文献   

6.
In vivo experiment alkaline polypeptide in kidney was established to have anticoagulant effect and increases the expression of receptors on T lymphocytes in burned patients. In the experiment renalin decreases the percentage of perished animals, normalizes the indices of homeostasis and energy metabolism in animals with the developed Mazugi nephritis. In rats, which received renalin, less proliferation of mesangial cells and the absence of balloon dystrophy was found histologically.  相似文献   

7.
Summary A modification of an established procedure for autoradiographic processing of cultured cells is described. This method eliminates the need for pipetting each individual well and also for cutting and dismantling the multiwell plate for slide preparation In this procedure the entire plate can be processed as a single unit and the cells can be analyzed in situ, thus eliminating the time consuming pipetting and cutting procedures. Furthermore, the entire experiment can be filed without use of additional slides or storage boxes. Hence, this is a simpler, time conserving, and economical way to process large numbers of cultures for thymidine labeling indices. This study was supported in part through a grant from the J. Graham Brown Regional Cancer Center, Louisville, Kentucky 40292.  相似文献   

8.
以富士苹果(Malus domestica‘Fuji’)为试材,测定其果实生长发育期间各生长指标的动态变化,选择5种理论生长方程对纵径、横径、单果重、体积、干重进行拟合,并根据拟合结果确定合适的生长方程建立各生长指标的数学模型,采用多项式拟合建立果形指数变化的数学模型,同时对果实各生长指标之间进行相关性分析。结果表明,果实纵径、横径生长适合选择Logistic方程,单果重、体积、干重适合选择Gompertz方程,果形指数的变化适合采用多项式拟合;果实纵径、横径、单果重、体积、干重两两之间均呈显著正相关,果形指数、果实干物质相对含量均与纵径、横径、单果重、体积、干重之间呈显著负相关,果实密度与纵径、横径、单果重、体积、干重之间呈显著负相关,而与果形指数、果实干物质相对含量之间呈显著正相关。  相似文献   

9.
Various diatom indices are routinely used in European countries to monitor water quality in waterways. In order to assess their sensitivities and their integration interval after a sudden and lasting environmental change, epilithic diatom biofilms were transferred from several polluted rivers to an unpolluted stream. To monitor the changes of the index values, the biofilms were sampled in a first experiment 20 and 40 days after transfer, and in a second experiment 30 and 60 days after transfer. Sensitivities of the indices to the water quality improvement were assessed calculating the differences between the index values of the reference and the transferred assemblages. Some indices have intermediate sensitivities (BDI, GDI, ILM, SLA), others higher sensitivities (CEE, EPI, ROT, SPI, TDI). The integration interval of these indices was 40–60 days. Some differences were observed between the indices, but their results were homogeneous when compared to those obtained with other metrics such as Bray-Curtis or Chord distances, used to assess the difference between the transferred and the reference diatom assemblages. These other metrics showed that even after 60 days, the transferred assemblages still differed from the reference. This underlines that metrics do not have the same integration intervals and do not assess the same stresses; the choice of the metric used to assess water quality is of prime importance.  相似文献   

10.
Leaf water status information is highly needed for monitoring plant physiological processes and assessing drought stress. Retrieval of leaf water status based on hyperspectral indices has been shown to be easy and rapid. However, a universal index that is applicable to various plants remains a considerable challenge, primarily due to the limited range of field-measured datasets. In this study, a leaf dehydration experiment was designed to obtain a relatively comprehensive dataset with ranges that are difficult to obtain in field measurements. The relative water content (RWC) and equivalent water thickness (EWT) were chosen as the surrogates of leaf water status. Moreover, five common types of hyperspectral indices including: single reflectance (R), wavelength difference (D), simple ratio (SR), normalized ratio (ND) and double difference (DDn) were applied to determine the best indices. The results indicate that values of original reflectance, reflectance difference and reflectance sensitivity increased significantly, particularly within the 350–700 nm and 1300–2500 nm domains, with a decrease in leaf water. The identified best indices for RWC and EWT, when all the species were considered together, were the first derivative reflectance based ND type index of dND (1415, 1530) and SR type index of dSR (1530, 1895), with R2 values of 0.95 (p < 0.001) and 0.97 (p < 0.001), respectively, better than previously published indices. Even so, different best indices for different species were identified, most probably due to the differences in leaf anatomy and physiological processes during leaf dehydration. Although more plant species and field-measured datasets are still needed in future studies, the recommend indices based on derivative spectra provide a means to monitor drought-induced plant mortality in temperate climate regions.  相似文献   

11.
Definition and Estimation of Higher-Order Gene Fixation Indices   总被引:1,自引:0,他引:1       下载免费PDF全文
Kermit Ritland 《Genetics》1987,117(4):783-793
Fixation indices summarize the associations between genes that arise from the joint effects of inbreeding and selection. In this paper, fixation indices are derived for pairs, triplets and quadruplets of genes at a single multiallelic locus. The fixation indices are obtained by dividing cumulants by constants; the cumulants describe the statistical distribution of alleles and the constants are functions of gene frequency. The use of cumulants instead of moments is necessary only for four-gene indices, when the fourth cumulant is used. A second type of four-gene index is also required, and this index is based upon the covariation of second-order cumulants. At multiallelic loci, a large number of indices is possible. If alleles are selectively neutral, the number of indices is reduced and the relationship between gene identity and gene cumulants is shown.--Two-gene indices can always be estimated from genotypic frequency data at a single polymorphic locus. Three-gene indices are also estimable except when allele frequency equals one-half. Four-gene indices are not estimable unless selection is assumed to have an equal effect upon each allele (such as under selective neutrality) and the locus contains at least three alleles of unequal frequency. For diallelic or selected loci, an alternative four-gene fixation index is proposed. This index incorporates both types of four-gene associations but cannot be related to gene identity.  相似文献   

12.
景观指数分类、应用及构建研究   总被引:193,自引:16,他引:193  
在景观生态学研究中,理解与把握景观格局变化的生态学原则至关重要,用景观指数描述景观格局及变化,建立格局与景观过程之间的联系,是景观生态学最常用的定量化研究方法,本文在综合前人对景观指数的基础上,对景观指数研究从景观指数的分类研究,指数对景观格局的描述研究,指数之间的相关性研究及指数构建研究等4方面进行了总结,并从单个景观指数与指数体系两个层次上提出了判定景观指数优劣及景观指数应用的一般性原则。  相似文献   

13.
14.
The study deals with a wide spectrum of indices of the electrolytic metabolism--sodium, potassium, calcium, chlorides, magnesium, iron, copper, zinc, cobalt and manganese--in blood, organs and tissues under the conditions of experimental chronic exposure of whole-body vibration frequency of 50 and 150 Hz and velocity of 85 mm.s-1 during a three months experiment (3 h daily) Reference methods were used for the determination of the indices--atom absorption spectrophotometry (variants with flame and without flame), coulometric chlorine titrator, flame photometry, etc. The indices were examined three times (1, 2 and 3rd months). Statistic analysis of the data showed significant changes in the number and the values of the indices and their character (increase or decrease) in comparison with the control values. The indices modifications occur early (at the end of the first month) and they proceed till the end of the experiment (till the end of the 3rd month) during the exposure to both frequencies, but are strongly expressed in the case of high frequency vibrations. The disorders in electrolytic metabolism established in the experiment testify that people exposed to vibrations are likely to suffer analogical changes and develop other pathologies--diseases of cardiovascular system, of blood and haematopoietic organs, etc. as well as an increase of specific disorders in connection with vibration exposure.  相似文献   

15.

1. 1. For the scientific evaluation of thermal environment in relatin to human health and comfort, a number of indices have been proposed in the recent 70 years.

2. 2. However, even the newest indices are still not sufficient to explain the general thermal environment for all people including infants, the aged, the disabled etc., because such indices are based more or less on experiments using college age persons.

3. 3. Series of studies to find required thermal conditions for the disabled and the aged have been carried out from 1976 in Japan and from 1988 in Hungary.

4. 4. In 1990, the Japanese and Hungarian research groups have collaborated in an international joint experiment on the thermal environment for the disabled.

5. 5. This paper reports on the results from the first step examinations of the data from above mentioned joint experiment.

Author Keywords: Disabled; thermal environment; health; comfort; international experiment  相似文献   


16.
Rapid analysis of drug effects on the cell cycle   总被引:5,自引:0,他引:5  
Using a flow cytometric technique to analyse DNA content and chromatin structure simultaneously, the following parameters of cell cycle progression were estimated in control and drug-treated L1210 cell cultures: (a) the kinetics of cell exit from the G1 phase; (b) the probability of cell exit from the indeterminate portion of the G1 phase, measured as the half-time of cell residence in that state; (c) the duration of the deterministic portion of G1 phase; (d) the rates of cell transit through selected "windows" in S phase; (e) the rate of cell entrance into mitosis; (f) the mean duration of the cell cycle (Tc). These parameters are obtained in a single stathmokinetic experiment from measurements of individual samples withdrawn at 30 min-1 hr intervals from Vinblasatine-treated cultures. In the same experiment mitotic indices are obtained with high statistical accuracy, and may be used to determine the terminal point of drug action. In addition to cell cycle analysis the method makes it possible to detect drug-induced changes in nuclear chromatin that are manifested by varying sensitivity of DNA in situ to denaturation by acid. Such changes were found to be associated with defective chromatin condensation, altered histone modifications or intercalation of the drugs into DNA. Using this technique the effects of sodium n-butyrate and two new antitumor drugs on L1210 cells were investigated.  相似文献   

17.
18.
In experiment on 25 cats reproducing small intestinal obstruction it has been established that the number of endocrine cells (EC) and the degree of their saturation with secretory granules increase in 3 and 6 h after the experiment. These indices decrease by 12 and 25 h after the experiment. The results obtained enable to reveal the EC participation in acute intestinal obstruction pathogenesis and to suppose the influence of released serotonin by paracrine way on mucous membrane as well as distant action on peristalsis and blood flow through intramural nerve plexus.  相似文献   

19.
Fresh crop and garden residues were applied both under laboratory conditions and in commercial greenhouse in order to asses their effect on soil nematodes populations and soil fertility. In the laboratory experiments, dosages of 5 to 20 g of cabbage residues, chicken manure, cabbage residues+chicken manure, grass+chicken manure, as well as leaves and stems of orange tree, pine tree, oleander, olive tree, palm tree and boxwood were mixed with 500 g soil having root-knot nematodes (Meloidogyne incognita) and soil moisture was adjusted at field capacity. A control treatment without residues was also included. The mixtures were kept into plastic bags, with four replications, and the bags were incubated for four weeks at 30 degrees C, when nematological and soil fertility analyses were carried out. In general, all these materials significantly (P < 0.05) reduced M. incognita populations and increased saprophagous nematodes, with slight effects on soil fertility except for the K increase with residues application. Tomato plants susceptible to M. incognita were planted in pots with 300 cm3 of the treated soils and kept for five weeks in a growth chamber (24 +/- 1 degrees C, 14 hours light), when root galling indices were evaluated. Most materials applied reduced root galling indices as regards to the control. In the greenhouse experiment, cabbage residues, cabbage residues+chicken manure, grass+chicken manure and grass+cabbage residues were applied to the soil and covered with a polyethylene sheet for 5 weeks. A cabbage residues:chicken manure treatment and a control (not-amended) treatment, without polyethylene, were also included. At the end of the experiment, the nematological analysis showed that all materials successfully controlled M. incognita populations, reaching 86-100% mortality with organic amendments vs. 6% for the control. After the greenhouse biodesinfestation experiment, a tomato crop was grown for one month, when root galling indices were determined. All materials significantly reduced this value from 4.75 in the control to 1.0-2.25 with the organic amendments, except for the cabbage residues+chicken manure treatment without polyethylene (index = 4.0). Our results show that fresh crop and garden residues successfully reduced M. incognita populations and root galling indices when applied with polyethylene covers, having good potential to be considered in integrated management programs.  相似文献   

20.
The Fulton‐condition factor ( K ) and per cent whole‐body water content were examined to determine whether these indices can estimate the proximate composition of juvenile lake herring Coregonus artedi exposed to a simulated Lake Superior winter over a 225 day laboratory experiment. The K was positively correlated to whole‐body crude lipid, crude protein, and gross energy content and negatively correlated to whole‐body water content for each sampling period of the experiment (days 75, 150 and 225). In contrast, there was only a weak positive correlation between K and whole‐body ash content. While per cent water content was negatively correlated with crude lipid, crude protein and gross energy content for each of the three sampling periods, the correlation between this predictor and ash content was only weakly negative. The indices can be used to accurately estimate temporal changes in proximate composition of juvenile lake herring during winter periods.  相似文献   

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