A matrix calculus for neural nets: II

In a previous paper a method was given by which the efferent activity of an idealized neural net could be calculated from a given afferent pattern. Those results are extended in the present paper. Conditions are given under which nets may be considered equivalent. Rules are given for the reduction or extension of a net to an equivalent net. A procedure is given for constructing a net which has the property of converting each of a given set of afferent activity patterns into its corresponding prescribed efferent activity pattern.     

Prerequisites for the on-line control of microbial processes by flow injection analysis.

Problems associated with the use of biosensors in process control, e.g. difficulties of sterilization and sensor fouling, are shortly displayed, and possibilities to overcome them are outlined. The advantages of flow injection analysis (FIA) are demonstrated and examples for efficient sampling systems connected with this method are reviewed. Special emphasis is given to problem-orientated sample pretreatments, preventing fast inactivation of immobilized enzymes in the analysis system. Examples of problem-orientated sample pretreatment units are given. A proposal for a computer-controlled self-calibrating FIA system is given.     

Maximum Likelihood Methods for Fitting the Burr Type XII Distribution to Life Test Data

This paper describes mathematical and computational methodology for estimating the parameters of the Burr Type XII distribution by the method of maximum likelihood. Expressions for the asymptotic variances and covariances of the parameter estimates are given, and the modality of the log-likelihood and conditional log-likelihood functions is analyzed. As a result of this analysis for various a priori known and unknown parameter combinations, conditions are given which guarantee that the parameter estimates obtained will, indeed, be maximum likelihood estimates. An efficient numerical method for maximizing the conditional log-likelihood function is described, and mathematical expressions are given for the various numerical approximations needed to evaluate the expressions given for the asymptotic variances and covariances of the parameter estimates. The methodology discussed is applied in a numerical example to life test data arising in a clinical setting.     

Likelihood Under the Mixed Model for Quantitative Traits

Mathematical details of obtaining the likelihood functions for testing hypotheses under the mixed model for quantitative traits are given. Since families are assumed to be chosen by the value of the trait of a particular family member, conditional distributions are required. Algorithms for efficient computation of the likelihood are given.     

THE POWER OF SENSORY DISCRIMINATION METHODS

Difference testing methods are extensively used in a variety of applications from small sensory evaluation tests to large scale consumer tests. A central issue in the use of these tests is their statistical power, or the probability that if a specified difference exists it will be demonstrated as a significant difference in a difference test. A general equation for the power of any discrimination method is given. A general equation for the sample size required to meet Type I and Type II error specifications is also given. Sample size tables for the 2-alternative forced choice (2-AFC), 3-AFC, the duo-trio and the triangular methods are given. Tables of the psychometric functions for the 2-AFC, 3-AFC, triangular and duo-trio methods are also given.     

Applications of Pick-Nevanlinna interpolation theory to retention-solubility studies in the lungs

Computational procedures for retention-solubility studies are given which determine data feasibility and some extreme properties of lung models compatible with given data. The procedures are analytic and are based on the interpolation theory of Pick and Nevanlinna.     

Conditions for the unlimited growth in multitype population size dependent galton-watson processes

Sufficient conditions are given for the unlimited growth or otherwise in multitype population size dependent Galton-Watson processes. These conditions are given in terms of moments of offspring distributions and extend known conditions for processes with one type.     

Testing Equality of Means and Simultaneous Confidence Intervals in Repeated Measures with Missing Data

In this paper, repeated measures with intraclass correlation model is considered when the observations are missing at random. An exact test for the equality of the mean components and simultaneous confidence intervals (Scheffé and Bonferroni inequality types) are given for linear contrasts of the mean components when the missing observations are of a monotone type. When the missing observations are not of the monotone type, the maximum likelihood estimates are obtained numerically by iterative methods given in Srivastava and Carter (1986). These estimators are then used to obtain asymptotic tests and confidence intervals for the equality of mean components and linear contrasts, respectively. An example is given to illustrate the method.     

Extensions of models for the estimation of mating systems using n independent loci

Inferences about plant mating systems increasingly use highly informative genetic markers, and investigate finer facets of the mating system. Here, four extensions of models for the estimation mating systems are described. (1) Multiallelic probabilities for the mixed selfing-random mating model are given; these are especially suitable for microsatellites; a generalized Kronecker operator is basis of this formula. (2) Multilocus probabilities for the "correlated-matings model" are given; interestingly, comparisons between single- vs multilocus estimates of correlated-paternity can provide a new measure of population substructure. (3) A measure of biparental inbreeding, the "correlation of selfing among loci", is shown to approximate the fraction of selfing due to uniparental (as opposed to biparental) inbreeding; also joint estimation of 1- 2- and 3-locus selfing rates allow separation, under a simple model, of the frequency vs the magnitude of biparental inbreeding. (4) Method-of-moments estimators for individual outcrossing rates are given. Formulae are given for both gymnosperms and angiosperms, and the computer program "MLTR" implements these methods.     

一类被开发的HollingⅢ类功能反应模型的定性分析

本文研究了一类捕食种群、食饵种群同时具有收获率的HollingⅢ类功能反应生态系统,其中食饵种群具有非线性密度制约,捕食者无密度制约.应用微分方程定性理论讨论了系统的平衡点,分析了中心焦点的阶数以及稳定性,所给定参数满足一定条件时系统不存在极限环,最后根据细焦点的稳定性判断出极限环的存在性,并验证了极限环的惟一性.     

Methods of analysing data to compare effects on populations of carrot fly (Psila rosae) larvae on carrots of treatments with exponentially-increasing doses of granular insecticide formulations

Effects of insecticide treatments were assessed by comparing the percentages of undamaged carrot roots on insecticide-treated and untreated check plots. A dose-response relationship based on a log-log transformation was derived and illustrated with data for six insecticides from two field experiments. Formulae are provided for estimating doses corresponding to given levels of decrease in the numbers of carrot fly larvae. Guidance is given on sample sizes needed and constraints on the accuracy of the estimates are stated. Examples are given of the use of the dose-response relationship to compare insecticide treatments within and between experiments.     

Estimatingdendroctonus frontalis (Coleoptera: Scolytidae) daily infestation dynamics

Summary Mathematical procedures are given to estimate infestation totals and daily life stage arrivals, departures, and mortality ofDendroctonus frontalis Zimmermann for an infested tree in the field. These estimates are based on minimal sample data and are designed to utilize all available information. Daily arrival estimates for larvae, pupae, and callow adults are obtained by indirect analysis without direct observation of these stages. The procedures are applied to 147 infested trees, and the results are transformed to a common time basis to obtain daily expectations by life stage for an “average” tree. These expectations suggest optimal times for field sampling or relative times of sampling when optimal times are missed. Expected daily arrival distributions by life stage for a single egg and a single attacking adult are given. Procedures are given for utilizing collateral information to obtain an infestation total and daily arrival estimates for a boundary life stage. The results of this study are applicable to anyD. frontalis field study, and the procedures given are applicable to any bark inhabiting insect having similar habits.     

New records of the plant bug subfamilies Bryocorinae,Deraeocorinae, and Mirinae (Heteroptera: Miridae) from the European part of Russia

New records of plant bug species are given for selected regions of European Russia based on the extensive collections of the Zoological Institute, Russian Academy of Sciences (St. Petersburg). The locality data and general distribution are given for all the 71 species included.     

The Decompositions for Point Symmetry Models in Two-way Contingency Tables

The decomposition for the complete point symmetry model in a rectangular contingency table is shown. Also the respective decompositions for the local point symmetry model and the reverse local point symmetry model in a square contingency table are given. Moreover test procedures for the decomposed models and an example are given.     

ADDENDUM

Mechanical analysis of the three grades of sand employed inthe above experiments gave the figures included in the followingtable, British Standard sieves Nos. 16, 30, 60, 150 and 300being used, with mechanical agitation. The apertures of thesesieves are not in all cases simple fractions of a millimetre,and the figures in the first column are given to the nearestsecond place of decimals. Assistance in these analyses was given by the Mining Dept.,Glasgow Royal Technical College. The figures for the Finnishsand are based on those given by Wilson and Burton (1938). Theslight discrepancy between the above figures for the analysisof the coarse quartz sand and those given previously (Bond,1938a) is due to the use of square-mesh sieves in the lateranalysis.     

A Markov transition model in the analysis of the immune response

A method for the analysis of repeated measures of immune response is given. Typically the reactions of response to stimulus do not occur at the same time for all experimental units so that regression models are inappropriate for this type of data. Instead Markov transition models are suggested and procedures given for testing differences among response patterns.     

Integrating conservation and development: effective trade-offs between biodiversity and cost in the selection of protected areas

Strategies are needed for reconciling competing demands at the regional level when areas are to be selected for protection and there are associated costs, possibly equivalent to forgone development opportunties. As an alternative to the fixed scaling (or weighting) of costs and benefits required by cost-benefit analysis, multi-criteria analyses allow the exploration of alternative weightings and a summary trade-off curve to determine preferred solutions. For alternative sets of areas, total cost could be plotted against total represented biodiversity, but a more consistent approach should look at trade-off space at the level of individual areas. For a given weighting, an area is assigned protection if and only if its contribution to total biodiversity, CB, exceeds its equivalent cost, EC (in biodiversity units). Because CB for a given area depends on which other areas are also protected, it can be more or less than EC. Here we develop an iterative strategy for selecting areas, such that, for a given weighting, an area is in the final protected set if and only if its final CB value is greater than its EC value. Sensitivity analysis is used to identify those areas that: (1) are assigned protection even when low weight is given to biodiversity, or (2) are not assigned protection even when high weight is given to biodiversity. This approach is applicable in principle to any surrogate measure for biodiversity; here examples are presented in which environmental data are summarized as an environmental space.     

The extraction of plasma 3-hydroxy-17-oxo steroid sulphates and the measurement of the constituent dehydroepiandrosterone sulphate and androsterone sulphate

1. A simple method for the extraction of 17-oxo steroid sulphates of plasma is described; glucosiduronates and orthophosphates are extracted, but to a smaller extent. 2. Four methods of analyses of the extracts are given and are relatively simple. Three of these are specific for steroid sulphates and two measure the sulphate conjugates directly. 3. Values for dehydroepiandrosterone sulphate and androsterone sulphate concentrations of normal and pathological plasmas are given.     

三种竞争种群的古典Gause-Lotka-Volterra系统

本文讨论了三种竞争种群的古典GLV系统．对系统所有非负平衡点的稳定性,进行了分析,给出了正平衡点全局稳定的充分条件,应用Hopf分支定理,我们给出了系统具有分支值的充分条件．