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1.
时间-温度、时间-湿度对球孢白僵菌孢子的互作效应 总被引:1,自引:1,他引:0
球孢白僵菌孢子的时间温度、时间湿度死亡率曲面经互补重对数(CLL)模型拟合,所得方程经HosmerLemoshow统计量检验显著,各处理强度(温度、湿度)与时间效应参数的t测验值大大超过极显著水平(P<0.0001).比较单因素分析与CLL模型估计的LT50值发现,有效时区内,不同水浴温度下,前者估计偏高;在较低湿度下(RH<33%),前者估计偏高,较高湿度下(RH>44%),前者估计偏低.较传统方法分析而言,该模型的优点在于反映出作用效应随时间变化和时间效应随作用因子变化的趋势信息 相似文献
2.
The study of life history dynamics of the pine sawyer beetle Monochamus carolinensis (Olivier) is of interest because the beetles are vectors for the pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, the causal agent of pine wilt in susceptible pine trees. Previous observation of a laboratory colony of M. carolinensis suggested numbers of adult beetles reared from logs varied little in relation to oviposition densities among individual logs. Logs in laboratory colonies are routinely subjected to artificially high oviposition rates. The objectives of this study were to examine the relationship between initial oviposition rate, holding time (time between log cut and oviposition), log volume and area and adult survivorship in laboratory colony. This study examined the number of eggs, larvae, adults and generation survivorship in logs over a 2‐year period. The number of adults emerged per log was not related to the number of eggs laid. Late larval and adult numbers were significantly correlated with log size. Only 12% of the initial cohort completed development and emerged as adults. We attribute the high within‐log mortality of beetles to intraspecific competition and cannibalism. 相似文献
3.
Kazuo Nakamura 《Population Ecology》1968,10(1):45-53
An wolf spider, Lycosa pseudoannulata, collected from the field were reared in test tubes supplied with fruit flies as the food, and the number and weight of fruit flies killed per unit time and the weight of residuum of killed flies were recorded. When the cumulative number of flies killed by a spider was plotted against time after the beginning of food supply, the angle of the curve obtained decreased gradually until a constant value. In this time, it seems that the gut of spider had saturated with food and the increase rate of number of flies killed reflects the rate of food disappeared from gut by assimilation and egestion. The amount of ingestion was obtained by subtracting the weight of residuum and the gain of live weight of the spider from the weight of killed flies. After the gut has saturated, the amount of food remained in the gut is considered to be equal to the capacity of gut, which is an essential factor in the study of predation. The amount of food disappearance from gut was also estimated. There was a linear relationship between the log body weight of spiders and the log capacity of gut. The linear relationship was also seen between the log total amount of ingestion and the log total amount of food disappeared from gut. 相似文献
4.
A method is described for the measurement of narcotic potencies of chemical compounds, using houseflies. Narcotic potency measurements give rise to statistical problems which differ from those encountered in toxicity determinations in so far as the narcotic process is reversible, and successive values of the number of affected insects in a group subjected to the test do not normally increase monotonically and in some case considerable oscillation occurs. An earlier method (Bradbury & Armstrong, 1954) used probit analysis, but it is now shown that this treatment and also regression analysis both fail to provide a valid method of dealing with variability in this type of test. A test based on the response of two flies, one male and one female per flask, is now described. The test, based on sixteen flies per compound, gave figures for: α0, the partial saturation of the test compound giving the same average knock-down time as chloroform at a partial saturation of 0.005; α1, the partial saturation of the test compound giving knock-down in I hr.; b, the slope of the straight line relating log. knock-down time to log. partial saturation; s, the residual standard deviation of log. knock-down time about its regression line on log. partial saturation. From these values the 95% confidence limits for the slope and for the values of α0 were calculated. The test also provided information on the convulsive action of compounds and a modification of it was used to determine knock-down times of very potent narcotics at high dosages. Results are presented for fifty-seven halogenated hydrocarbons and the hypothesis that variations in potency between narcotics are determined mainly by rates of diffusion is examined. The results do not support this hypothesis. Narcotic and convulsant potencies measured by the method described are a useful guide to the behaviour of compounds in mouse tests. 相似文献
5.
Dominici F Zanobetti A Zeger SL Schwartz J Samet JM 《Biostatistics (Oxford, England)》2004,5(3):341-360
In this paper we develop a hierarchical bivariate time series model to characterize the relationship between particulate matter less than 10 microns in aerodynamic diameter (PM10) and both mortality and hospital admissions for cardiovascular diseases. The model is applied to time series data on mortality and morbidity for 10 metropolitan areas in the United States from 1986 to 1993. We postulate that these time series should be related through a shared relationship with PM10. At the first stage of the hierarchy, we fit two seemingly unrelated Poisson regression models to produce city-specific estimates of the log relative rates of mortality and morbidity associated with exposure to PM10 within each location. The sample covariance matrix of the estimated log relative rates is obtained using a novel generalized estimating equation approach that takes into account the correlation between the mortality and morbidity time series. At the second stage, we combine information across locations to estimate overall log relative rates of mortality and morbidity and variation of the rates across cities. Using the combined information across the 10 locations we find that a 10 microg/m3 increase in average PM10 at the current day and previous day is associated with a 0.26% increase in mortality (95% posterior interval -0.37, 0.65), and a 0.71% increase in hospital admissions (95% posterior interval 0.35, 0.99). The log relative rates of mortality and morbidity have a similar degree of heterogeneity across cities: the posterior means of the between-city standard deviations of the mortality and morbidity air pollution effects are 0.42 (95% interval 0.05, 1.18), and 0.31 (95% interval 0.10, 0.89), respectively. The city-specific log relative rates of mortality and morbidity are estimated to have very low correlation, but the uncertainty in the correlation is very substantial (posterior mean = 0.20, 95% interval -0.89, 0.98). With the parameter estimates from the model, we can predict the hospitalization log relative rate for a new city for which hospitalization data are unavailable, using that city's estimated mortality relative rate. We illustrate this prediction using New York as an example. 相似文献
6.
Romanovskiĭ IuE 《Zhurnal obshche? biologii》2001,62(1):25-33
Although the life history evolution of small- and large-bodied mammals seems to be governed by different factors, the both shows relative neonate size and juvenile survival to be slightly dependent on body mass. I propose a hypothesis that natural selection simultaneously maximizes a time to maturity (minimizes somatic growth rate) and a number of newborn survived to reproduction. In this case optimal juvenile survival of large-bodied mammals must be close to e-beta and that of small-bodied approximately e-(1 + beta), where beta is the slope of the regression of log annual fecundity on log annual juvenile mortality. Analysis of vital characters for 71 mammal species revealed the slope to be close to unity. As a result frequency distribution of log juvenile survival shows bimodality which coincides well with predicted optimal survival for large- and small-bodies species. It is shown that the relative neonate size can be directly proportional to the juvenile survival and inversely proportional to the lifetime offspring production irrespective of mortality factors. 相似文献
7.
Disinfection kinetic studies of sodium dodecyl sulphate, benzalkonium chloride and sodium hypochlorite against Staphylococcus aureus revealed that when a higher inoculum level of Staph. aureus than normal was used (approximately 1 log higher), the efficacy of disinfection was severely attenuated. Kinetic analysis using the Hom model for experiments carried out on tests using 3 x 108 organisms ml-1 were unable to account for the large increase in disinfection power observed when smaller inoculum levels were used. Since the inoculum was the same in every way except for the numbers used, the large variations in the log reduction/time curves could not be explained by a variation in the resistance of the population to the biocide, as identical log reduction-time curves should have resulted. The level of disinfection achieved for a given concentration of biocide was found to be approximately linearly related to the cell number ml-1 of test solution and not to the log number. The variation observed is believed to occur due to intrinsic self-quenching of the biocide by the microbes during the course of the disinfection test. As the level of free biocide decreases, the rate of reaction decreases, giving the tails of the log reduction/time curves. Such intrinsic self-quenching could explain the large variations known to occur in the legally required disinfection suspension tests. 相似文献
8.
J. P. Aggleton J. M. Bland R. W. Kentridge N. J. Neave 《BMJ (Clinical research ed.)》1994,309(6970):1681-1684
OBJECTIVE--To test whether handedness is associated with a change in longevity. DESIGN--Archival survey. SETTING--British Isles. SUBJECTS--All first class cricketers born before 1961 whose bowling hand was specified (right, n = 5041; left, n = 1132) in a comprehensive encyclopaedia. MAIN OUTCOME MEASURES--Bowling hand and life span. RESULTS--Regression analysis of the 5960 players born between 1840 and 1960 (3387 dead, 2573 alive) showed no significant relation between mortality and handedness (P = 0.3). Left handedness was, however, associated with an increased likelihood of death from unnatural causes (P = 0.03, log hazard 0.37, 95% confidence interval 0.04 to 0.70). This effect was especially related to deaths during warfare (P = 0.009, log hazard 0.53, 0.13 to 0.92). CONCLUSION--Left handedness is not, in general, associated with an increase in mortality. 相似文献
9.
T J Pickering S Garforth J R Sayers J A Grasby 《The Journal of biological chemistry》1999,274(25):17711-17717
T5 5'-3'-exonuclease is a member of a family of homologous 5'-nucleases essential for DNA replication and repair. We have measured the variation of the steady state parameters of the enzyme with pH. The log of the association constant of the enzyme and substrate is pH-independent between pH 5 and 7, but at higher pH, it decreases (gradient -0.91 +/- 0.1) with increasing pH. The log of the turnover number increases (gradient 0.9 +/- 0.01) with increasing pH until a pH-independent plateau is reached. The T5 5'-3'-exonuclease-catalyzed reaction requires the protonation of a single residue for substrate binding, whereas kcat depends on a single deprotonation as demonstrated by the bell-shaped dependence of log (kcat/Km) on pH. To investigate the role of a conserved lysine (Lys-83), the pH profile of log (kcat/Km) of a K83A mutant was determined and found to increase with pH (gradient 1.01 +/- 0. 01) until a pH-independent plateau is reached. We therefore conclude that protonation of Lys-83 in the wild type protein facilitates DNA binding. The origin of the pH dependence of the kcat parameter of the wild type enzyme is discussed. 相似文献
10.
1. The Lobular Giant Movement Detector neurone (LGMD) of Schistocerca responds with spikes when small areas of the visual field change in luminance. Previous work has shown that changes of +/- 1 log 10 unit are enough to produce maximal ON and OFF responses. 2. Using a 5 degree test area, it is shown that the number of spikes generated by such a stimulus depends on the luminance of the surrounding area. When the surround is dark, the response is maximal; when it is brightly lit, the response is minimal. Intermediate intensities produce intermediate values of response. A X 2 change in response is produced by about 3 log 10 units change in surround intensity. 3. A bright annulus, with diameters of 10-5 degrees and 25-8 degrees, inhibits both ON and OFF responses when concentric with the 5 degree test area, but not when it is 30 degrees eccentric to the test area. The inhibitory effect shows no decrease after 4 min. 4. These results are interpreted to indicate a tonic lateral inhibitory network, sited peripherally in the optic lobe prior to the divergence of the separate ON and OFF channels found in the projection from the medulla to the LGMD. It is probably identical with that described for the lamina by previous workers. 相似文献
11.
FINNEY DJ 《The Annals of applied biology》1946,33(2):160-165
When a set of insecticidal toxicity tests yields parallel regression lines for the relationship between mortality probit and log dose, the potencies of the materials or conditions under test may be compared purely in terms of log L.D. 50's. The purpose of this paper is to suggest that, when tests have been made with all combinations of several different factors, standard methods for the statistical analysis of factorial experiments may be adapted to the examination of the relative potencies.
Data obtained by Potter & Gillham (1046), in a 2' factorial experiment on alternative storage conditions for insects before and after spraying and the adjuvant action of terpineol in a pyrethrins spray, are used in an example of the computations. Details are given of the test of parallelism of the regression lines, the factorial analysis of the log L.D. '50s, the estimation of the mean effects and interactions and their standard errors, the significance tests, and the preparation of summary tables. 相似文献
Data obtained by Potter & Gillham (1046), in a 2' factorial experiment on alternative storage conditions for insects before and after spraying and the adjuvant action of terpineol in a pyrethrins spray, are used in an example of the computations. Details are given of the test of parallelism of the regression lines, the factorial analysis of the log L.D. '50s, the estimation of the mean effects and interactions and their standard errors, the significance tests, and the preparation of summary tables. 相似文献
12.
D M Zucker 《Biometrics》1992,48(3):893-899
For comparison of two survival distributions, it is natural to use a weighted log-rank test with weight function given by the log hazard ratio function that is anticipated a priori. This paper investigates the efficiency of this test when the a priori estimate of the log hazard ratio is subject to a specified percentage error. The test is shown to be the maximum efficiency robust test over the class of alternatives in question and a simple expression for the maximum efficiency is established. 相似文献
13.
The effect of habitat stability on benthic invertebrate communities: the utility of species abundance distributions 总被引:3,自引:1,他引:2
R. G. Death 《Hydrobiologia》1996,317(2):97-107
Spatial and temporal patterns in the species abundance distribution of benthic invertebrate communities of 11 freshwater habitats (10 streams and a wind-swept lake shore) were examined with respect to habitat stability. Abundance patterns varied markedly between seasons at most sites. However, mean abundance distributions at 4 of the 5 unstable sites and the 2 most stable sites were dominated by one or two taxa with a large number of rare species, whereas sites of intermediate stability had more equitable distributions. Both the log series and log normal distributions were statistically indistinguishable, at the 5% level, from all the observed mean abundance patterns. In contrast, graphical comparisons of the observed and fitted distributions suggested the log series may be the better fit at most of the unstable sites and the two most stable sites, whereas the more equitable distribution at sites of intermediate stability suggested the log normal distribution was the better fit. If conditions at a site favoured one or two species, either through severe physical conditions, or through competitive superiority in the absence of disturbance then the log series distribution may result. However, if no species in the community was strongly advantaged over others, a log normal distribution should result. Given the discriminating power of the appropriate statistical test it may not, however, be possible to pick up these differences without graphical comparisons as well. 相似文献
14.
Romanovskiĭ IuE 《Zhurnal obshche? biologii》2002,63(5):371-381
Most studies on life-history evolution discuss the necessity of distinguishing between extrinsic and intrinsic sources of variability in life-history traits. I use log/log plots of yearly neonate production in daugters (b) versus adult mortality (Ma) for 75 bird species and 88 mammal species to compare graphically life-history "fields" arranged by these selective forces along a "slow-fast continuum". Under the assumptions of steady-state and linear relationship between adult mortality and reproductive effort, as well as between juvenile survival and relative neonate weight, it is possible to place additional axes in the two-dimentional plot, and to predict covariations among demographic and individual growth traits. The functional regression analysis shows, that the assumptions are completely fulfilled, at least for birds, but mammals show nonlinear relationship between adult mortality and reproductive effort. This can be explained by peculiarities of metabolism and parental care in small mammals with high reproductive output. Hence, for birds the axis of relative neonate weight approximately coincides in direction with the juvenile survivorship axis, but this is not a case for mammals. In both taxa, the relative neonate weight is an invariant in relation to fecundity and adult mortality (but not in relation to adult body weight). This important feature, together with other intrinsic (energetic and phylogenetic) constraints, explains well-documented close covariations among traits, even when the effect of body size is factored out. It is argued that life-history and body size variations in birds and mammals mainly depend on a pattern of temporal resource deficiency, although this impact cannot be separated from that of extrinsic juvenile mortality. 相似文献
15.
Precautions when determining kinetically the order of inactivation of enzymes by functionally irreversible inhibitors 总被引:4,自引:0,他引:4
G M Carlson 《Biochimica et biophysica acta》1984,789(3):347-350
The number of molecules of an irreversible inhibitor that are responsible for inactivation of a catalytic site is often deduced from the slope of a plot of the log of the apparent rate of inactivation (k') at different concentrations of inhibitor versus the log of the inhibitor concentrations. The purpose of this note is to urge caution in experimental design and interpretation if one attempts to utilize this kinetic technique to characterize the order of inactivation brought about by functionally irreversible inhibitors that initially bind reversibly to an enzyme in the process of inactivation. Representative literature cases which have utilized plots of log k' versus log [I] for this type of inactivation are discussed. 相似文献
16.
Inhibitory effect of various lactobacilli against pathogenic strains of E. coli in model system Caco2 cells was determined by enumerating the number of adhering E. coli after pre-incubation (exclusion), post-incubation (displacement) or co-incubation (competition) with lactobacilli. Porcine E. coli strain F107 (F18ab, Stx2v) in the competition assay with porcine lactobacillus strain P10 gave bacterial counts 7.25 (log CFU per well); in the exclusion test it was only 7.05 while in displacement test it reached 7.29. The lowest E. coli counts adhering to Caco-2 cells were in exclusion assay (pre-incubation, Lactobacillus inoculated as the first). Pre-treatment of E. coli with our lactobacilli strains reduced the cultivable E. coli numbers. 相似文献
17.
D. J. Finney MA. 《The Annals of applied biology》1944,31(1):68-74
When data from toxicity tests have to be adjusted for a mortality rate amongst untreated controls, three modifications to the usual method of probit analysis need to be considered. The full solution is more laborious than that ordinarily used, as it requires the estimation of this mortality rate from the whole of the data. When the rate is. not high (e.g. up to 20 %) a satisfactory approximation may be obtained by a simple alteration in die weighting coefficients, especially if the precaution is taken of using two or three times as many test organisms as controls as for any dosage of the poison, thus decreasing the relative value of the information on natural mortality contributed by the treated batches. The modified weighting coefficients are tabulated for values of the natural mortality from zero to 20 %. An example of the more complex calculations required for the full maximum likelihood solution is discussed in detail. 相似文献
18.
Factors affecting the diversity of flora and vegetation in central European settlements 总被引:5,自引:0,他引:5
P. Pyšek 《Plant Ecology》1993,106(1):89-100
Published data on the number of plant species and/or communities were gathered for 77 European cities and 85 villages. The relationships between the floristic and vegetation diversity and some environmental variables were analysed. Species number in cities showed log linear increase with city size (expressed as the population size or city area). A linear increase in the species number with size was found in the village flora. The richness of both city and village flora was not significantly related to any climatic variable. On the contrary, the number of communities in both villages and cities was correlated not only with settlement size but also with altitude and mean annual temperature. The diversity of village vegetation was closely related to the climax type of the respective region. The features of human settlements that make it possible to consider them as landscape islands are discussed. 相似文献
19.
Annika Hofgaard 《植被学杂志》1993,4(6):773-782
Abstract. Changes in the tree layer (> 1.3m) and sapling layer (< 1.3m, including seedlings) of a Swedish boreal old-growth Picea abies (Norway spruce) forest from the 1930s to the 1980s were studied in permanent plots. The plots were established in 1938–1939 and re-analysed in 1983–1988. Regeneration, mortality, turnover rate in the tree layer and amount of decomposing logs as well as the time required for complete decomposition of logs were investigated using the detailed data from the 1930s. Ca. 25 % of the trees present during the first analysis were no longer alive. This mortality was balanced by recruitment from the sapling layer. The rate of mortality suggests a turnover time for the tree layer of ca. 200 yr. The number of spruces in the sapling layer has increased by ca. 85 %, hypothetically in response to an increase in amount of decomposing wood that can serve as nurse logs and stumps. The mean time for total decomposition was calculated as ca. 200 yr. Spruce regeneration on logs does not occur until the log is at least ca. 50 yr old. The survival pattern in the sapling layer suggests a high mortality rate at the seedling stage (≤ 1 yr) and a low mortality rate at the sapling stage. In conclusion, it is suggested that the amount of coarse woody debris available for regeneration, the occurrence of seedlings, and seedling mortality constitute concurrent factors through which climatic fluctuations, in a long-term perspective, direct stand recruitment and density. As a consequence, these boreal forests will be kept in a dynamical equilibrium. 相似文献
20.
CLIFFORD RAY JOHNSON 《Zoological Journal of the Linnean Society》1973,52(3):217-230
A collection in excess of 1000 specimens of Callionymus kaianus moretonensis, trawled off southern Queensland, afforded an opportunity to study various aspects of the biology of this species. It inhabits muddy bottoms at depths of 101–150 m off south-east Queensland between Noosa and Cape Moreton, Moreton Island. Penaeid prawns were the predominant food during all seasons and for all size groups. A great diversity of food items were ingested, especially in the pelecypod and gastropod categories. Factors influencing feeding and vulnerability of prey organisms are discussed. Of the 907 specimens that were sexed, 422 (46.7%) were males and 485 (53.3%) were females. C. k. moretonensis has a prolonged breeding period in which each female spawns a number of times. Only a few oocytes appear to be discharged at any one time from the ovary. Practically every stage of ovarian development was found in each ovary examined regardless of time of year. Oocyte diameter averaged 0.51 mm immediately prior to spawning and numbers of ova ranged from 1285 to 22,478. C. k. moretonensis may have either a benthic larvae or a short-lived planktonic one. Length-weight relationships are represented by the regressions, log W = -1 5.24 + 3.77 log L (males) and log W = -16.77 + 4.12 log L (females). Otoliths were used for age and growth determinations. C. k. moretonensis reaches age group IV+. Growth of males slightly exceeded that of females, with the greatest difference occurring between the third and fourth years of life. No evidence of high post-breeding mortality was found in spent males. 相似文献