A NEW PROCEDURE FOR RAPIDLY ESTIMATING EUROPEAN PINE SAWFLY (HYMENOPTERA: DIPRIONIDAE) POPULATION LEVELS IN YOUNG PINE PLANTATIONS

1971 ◽  
Vol 103 (9) ◽  
pp. 1315-1322 ◽  
Author(s):  
Louis F. Wilson ◽  
Douglas J. Gerrard
Keyword(s):  
Negative Binomial ◽  
Confidence Bands ◽  
Pine Plantations ◽  
Scotch Pine ◽  
Simple Criterion ◽  
Pine Sawfly ◽  
Insect Populations ◽  
The Mean ◽  
European Pine Sawfly ◽  
Image Position

AbstractA method is proposed for rapidly estimating the population levels of European pine sawfly in young red and Scotch pine plantations. On the hypothesis that the numbers of larval colonies per tree are distributed within a stand according to a negative binomial series, it is shown that an estimate Y of the mean sawfly count per tree in any relevant pine stand may be predicted from knowledge of the proportion p of trees infested, by means of the equationin which k is an estimate of a distribution parameter. The estimate k is derived beforehand, by Maximum Likelihood from a series of insect populations representative of those in which predictions are contemplated.Approximate 95% confidence limits for estimated densities are computed from a variance estimator reflecting two sources of error. The plotted confidence bands pertaining to samples of various size furnish a simple criterion for judging directly from the proportion of infested trees whether or not suppression measures are needed in a plantation.

Monitoring European pine sawfly population densities with pheromone traps in young pine plantations

1999 ◽  
Vol 124 (2-3) ◽  
pp. 113-121 ◽  
Author(s):  
Päivi Lyytikäinen-Saarenmaa ◽  
Olle Anderbrant ◽  
Jan Löfqvist ◽  
Erik Hedenström ◽  
Hans-Erik Högberg
Keyword(s):  
Pine Plantations ◽  
Pheromone Traps ◽  
Population Densities ◽  
Pine Sawfly ◽  
European Pine Sawfly

scholarly journals The dynamics of the spread of pine sawfly in the forests of the Bryansk region

2015 ◽  
Vol 5 (1) ◽  
pp. 54-65
Author(s):  
Кистерный ◽  
Grigoriy Kisternyy ◽  
Шепель ◽  
Igor Shepel
Keyword(s):  
Weather Conditions ◽  
Forest Litter ◽  
Pine Plantations ◽  
Fodder Trees ◽  
Sawfly Larvae ◽  
Pine Sawfly ◽  
Pest Outbreaks ◽  
Wide Range ◽  
Definition Of ◽  
European Pine Sawfly

On the basis of forest pathology survey of pine plantations of the Bryansk region for the period of 2011-2014, the nature of the centers of the European pine sawfly is studied and the reasons for their change are established. Works are made in the definition of the number of larvae per one tree in the growth phase of the outbreak, cocoons, male adults, and the sanitary conditions of pine forests on 5 plots in pest outbreaks are evaluated. The area of distribution of foci ranged from 896.6 to 8176.8 ha depending on the year of survey and prevailed in maturing pine plantations. There was a wide range of defoliation of trees - from mild to complete. Average condition category of plots in pine plantations, partially restored after damage was 1.84-2.42. The average number of sawfly larvae per tree has reached an average of 308 pieces. Previously unknown method for selecting the place of their cocoon - a thicker crust of fodder trees is discovered. Relatively low density of sawfly cocoons in the forest litter - 1-17 pcs/m2 is set. At the regional level for the first time, to assess the intensity of the flight of the European pine sawfly and prognosis of foci used pheromone traps were used. The number of males caught in traps varied over wide limits. Mixed results when comparing the two observation periods in 2013 and 2014 are got and the dependence of flight on the weather conditions at that time is shown. Broad ecological plasticity of this species in its ability to form foci in various conditions is confirmed.

A note on a simple criterion for choosing among sample joints for use in double sampling

1983 ◽  
Vol 36 (3) ◽  
pp. 493-495 ◽  
Author(s):  
G. L. Cook ◽  
D. W. Jones ◽  
A. J. Kempster
Keyword(s):  
Standard Deviation ◽  
Standard Error ◽  
Double Sampling ◽  
Simple Criterion ◽  
Optimum Proportion ◽  
The Mean ◽  
The One ◽  
Image Position ◽  
The Cost

ABSTRACTA simple criterion is described for selecting which of a number of sample joints estimates most precisely for a given cost (T) the mean lean percentage of a population of carcasses, using double sampling. It is shown that the best joint is the one giving the largest value of:where ρ is the correlation between the lean content of the sample joint and the lean content of a carcass side (y), and k is the cost of the sample joint dissection as a proportion of the cost of side dissection. The optimum proportion of carcasses to side dissect is:and the standard error of the estimated mean is then:where σyis the standard deviation of y and C is the cost of measuring y.

scholarly journals INFLUENCE OF STATISTICAL FLUCTUATIONS ON K/π RATIOS IN RELATIVISTIC HEAVY ION COLLISIONS

2001 ◽  
Vol 16 (07) ◽  
pp. 1227-1235 ◽  
Author(s):  
C. B. YANG ◽  
X. CAI
Keyword(s):  
Negative Binomial ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Relative Variance ◽  
Ion Collisions ◽  
Statistical Fluctuations ◽  
Binomial Distributions ◽  
The Mean ◽  
Multiplicity Distributions ◽  
Statistical Background

The influence of pure statistical fluctuations on K/π ratio is investigated in an event-by-event way. Poisson and the modified negative binomial distributions are used as the multiplicity distributions since they both have statistical background. It is shown that the distributions of the ratio in these cases are Gaussian, and the mean and relative variance are given analytically.

scholarly journals AVERAGING OF AN INCREASING NUMBER OF MOMENT CONDITION ESTIMATORS

2014 ◽  
Vol 32 (1) ◽  
pp. 30-70 ◽  
Author(s):  
Xiaohong Chen ◽  
David T. Jacho-Chávez ◽  
Oliver Linton
Keyword(s):  
Moment Condition ◽  
Moment Conditions ◽  
Parameter Heterogeneity ◽  
Class Of Estimators ◽  
Optimal Weighting ◽  
The Mean ◽  
The Moment ◽  
Image Position ◽  
Nonlinear Estimators ◽  
Available Information

We establish the consistency and asymptotic normality for a class of estimators that are linear combinations of a set of$\sqrt n$-consistent nonlinear estimators whose cardinality increases with sample size. The method can be compared with the usual approaches of combining the moment conditions (GMM) and combining the instruments (IV), and achieves similar objectives of aggregating the available information. One advantage of aggregating the estimators rather than the moment conditions is that it yields robustness to certain types of parameter heterogeneity in the sense that it delivers consistent estimates of the mean effect in that case. We discuss the question of optimal weighting of the estimators.

The focusing of radiation by a random surface when the source is at a finite distance

1960 ◽  
Vol 56 (1) ◽  
pp. 27-40 ◽  
Author(s):  
M. S. Longuet-Higgins
Keyword(s):  
Mean Curvature ◽  
Joint Distribution ◽  
Total Curvature ◽  
Statistical Distribution ◽  
Constant Parameter ◽  
Random Surface ◽  
Second Derivatives ◽  
Finite Distance ◽  
The Mean ◽  
Image Position

Imagine a nearly horizontal, statistically uniform, random surface ζ(x, y), Gaussian in the sense that the second derivatives , , have a normal joint distribution. The problem considered is the statistical distribution of the quantitywhere J and Ω denote the mean curvature and total curvature of the surface, respectively, and ν is a constant parameter.

A Negative Binomial Regression Model for Accuracy Tests

2012 ◽  
Vol 36 (2) ◽  
pp. 88-103 ◽  
Author(s):  
Lai-Fa Hung
Keyword(s):  
Negative Binomial ◽  
Social Science Research ◽  
Poisson Model ◽  
Negative Binomial Regression ◽  
Science Research ◽  
Likelihood Method ◽  
Estimation Methods ◽  
Negative Binomial Regression Model ◽  
Marginal Maximum Likelihood ◽  
The Mean

Rasch used a Poisson model to analyze errors and speed in reading tests. An important property of the Poisson distribution is that the mean and variance are equal. However, in social science research, it is very common for the variance to be greater than the mean (i.e., the data are overdispersed). This study embeds the Rasch model within an overdispersion framework and proposes new estimation methods. The parameters in the proposed model can be estimated using the Markov chain Monte Carlo method implemented in WinBUGS and the marginal maximum likelihood method implemented in SAS. An empirical example based on models generated by the results of empirical data, which are fitted and discussed, is examined.

scholarly journals VI.—The Body-Temperature of Fishes and other Marine Animals.

1908 ◽  
Vol 28 ◽  
pp. 66-84 ◽  
Author(s):  
Sutherland Simpson
Keyword(s):  
Body Temperature ◽  
Temperature Difference ◽  
Great Majority ◽  
The Body ◽  
Shore Crab ◽  
First Year ◽  
Marine Animals ◽  
Mean Temperature ◽  
The Mean ◽  
Image Position

SUMMARYThe body-temperature of the following fishes, crustaceans, and echinoderms has been examined and compared with the temperature of the water in which they live:—Cod-fish (Gadus morrhua), ling (Molva vulgaris), torsk (Brosmius brosme), coal-fish or saithe (Gadus virens), haddock (Gadus œgelfinus), flounder (Pleuronectes flesus), smelt (Osmerus eperlanus), dog-fish (Scyllium catulus), shore crab (Carcinus mœnas), edible crab (Cancer pagurus), lobster (Homarus vulgaris), sea-urchin (Echinus esculentus), and starfish (Asterias rubens). The minimum, maximum, and mean temperature difference for each species are given in the following table:—The excess of temperature is most evident in the larger specimens. This is well shown in the case of the coal-fish, where in the adult it was 0°·7 C., and in the great majority (11 out of 12) of the young of the first year, 0°·0 C. The body-weight and the conditions under which the fish are captured probably form the most important factors in determining the temperature difference.In 14 codfish, where the rectal, blood, and muscle temperatures were recorded in the same individual, it was found to be highest in the muscle and lowest in the rectum, the mean temperature difference being 0°·46 C. for the muscle, 0°·41 C for the blood, and 0°·36 C. for the rectum.

scholarly journals Effects of cell cycle variability on lineage and population measurements of mRNA abundance

2020 ◽  
Author(s):  
Ruben Perez-Carrasco ◽  
Casper Beentjes ◽  
Ramon Grima
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Negative Binomial ◽  
Eukaryotic Cell ◽  
Cycle Duration ◽  
Cell Cycle Duration ◽  
Monotonically Decreasing Function ◽  
Binomial Mixture ◽  
A Cell ◽  
The Mean

AbstractMany models of gene expression do not explicitly incorporate a cell cycle description. Here we derive a theory describing how mRNA fluctuations for constitutive and bursty gene expression are influenced by stochasticity in the duration of the cell cycle and the timing of DNA replication. Analytical expressions for the moments show that omitting cell cycle duration introduces an error in the predicted mean number of mRNAs that is a monotonically decreasing function of η, which is proportional to the ratio of the mean cell cycle duration and the mRNA lifetime. By contrast, the error in the variance of the mRNA distribution is highest for intermediate values of η consistent with genome-wide measurements in many organisms. Using eukaryotic cell data, we estimate the errors in the mean and variance to be at most 3% and 25%, respectively. Furthermore, we derive an accurate negative binomial mixture approximation to the mRNA distribution. This indicates that stochasticity in the cell cycle can introduce fluctuations in mRNA numbers that are similar to the effect of bursty transcription. Finally, we show that for real experimental data, disregarding cell cycle stochasticity can introduce errors in the inference of transcription rates larger than 10%.

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