A further note on Kiritani and Nakasuji’s model for stage-frequency data including comments on the use of Tukey’s jackknife technique for estimating variances

Summary Some general equations for stage-frequency estimation are presented and their applications discussed.Tukey’s (1958) jackknife technique is suggested for the calculation of the approximate variances associated with estimators of population parameters.     

Estimating developmental and mortality rates and stage recruitment from insect stage-frequency data

A model for the analysis of insect stage-frequency data is developed which includes stage-specific variable developmental periods and stage-specific daily survival rates. The model can predict the development of an insect population through its developmental stages and consequently may form the basis for a simulation model of the population.     

A method for estimating natural survival rate and mean fecundity of an adult insect population by dissecting the female reproductive organs

Several problems were discussed in relation toMacDonald' s method (MacDonald , 1957) for estimating the survival rate of a natural population of adults with varying survival rates and unstable age structure.

1. Random samplings with a fixed sampling ratio and an appropriate census interval is pre-requisite during the occurrence of the adults.
2. At each sampling, female adults are dissected to know the ratio, p_i, of nulliparous females in ith sample (i=0, 1, 2, 3, …,). The Σn_ip_i/Σn_i gives an estimate of the ratio, Fα/F, of nulliparous females in the population where n_i refers to the population size on ith census date. If a constant daily survival rate is assumed, the daily survival rate is estimated from equation (4′). When the survival rate is not constant over the period of adult occurrence, e. g. before and after the initiation of oviposition, the survival rate during pre-ovipositional period is estimated by equation (4″).
3. Decision of an economic census interval to obtain a reliable estimate of the ratio, Fα/F, is depending on the form of emergence curve, particularly on its duration and the length of pre-ovipositional period. If the normal distribution can be assumed for the emergence curve, an interval less than one third of the emergence period is recommended. Concerning with insects having a long pre-ovipositional period, a census interval which exceeds one third of the emergence period still gives a good estimate of Fα/F.
4. The mean realized fecundity of some kind of insects can be estimated by equation (5′ or 5″) using the estimates obtained by the present method.

     

Extensions to Kiritani and Nakasuji’s method for analysing insect stage-frequency data

Summary There is evidence that the simple method ofKiritani andNakasuji (1967) for the analysis of insect stage-frequency data produces estimates of stage-specific survival rates that compare well with the estimates from more complicated methods (Manly, 1975). However the method as originally proposed byKiritani andNakasuji cannot always be applied because it assumes that the insect population involved was sampled at regular intervals of time. Furthermore, parameters such as the durations of stages are not estimated. In this note modifications to the basic method are suggested with the idea of overcoming these limitations.     

A simulation study of population interaction between the greenhouse whitefly,Trialeurodes vaporariorum Westwood (Homoptera: Aleyrodidae), and the parasitoidEncarsia formosa gahan (Hymenoptera: Aphelinidae) I. Description of the model

A simple simulation model was developed to simulate the population dynamics of the system of the greenhouse whitefly (Trialeurodes vaporariorumWestwood ) and the parasitoid Encarsia formosaGahan . On the assumption that temperature is constant, the whitefly population was described as theLeslie Matrix model. Parasitization and host feeding by the parasitoid population were modelled by means of a modified disc equation. The validity of the model was demonstrated by comparing the predictions of the model with the observed values obtained in greenhouse experiments.     

Application of a marking-and-recapture method for the analysis of larval-adult populations of an insect,Nezara viridula (Hemiptera: Pentatomidae)

Difficulty arises in applying marking-and-recapture methods to insects when the probability of recapture of marked individuals is changed with advancing age, either due to detachment of the mark by moulting (in the case of larvae) or to changes in their survival rate or their behaviour. A modification of the re-recapture method (Leslie et al., 1953) has been devised to analyze the capture-recapture data of the 5th-instar larvae and adults of Nezara viridula L. Estimation of the rate of moulting to the adult stage is made with the aid of additional information on larval survival. Migration rates of the larvae between the two halves of the census field is estimated byIwao's (1963) method. Through these analyses, the dynamic feature of the population during transition from the 5th instar to, adult is revealed. Several problems involved in the application of marking-and-recapture methods to insect populations are discussed.     

Control of data quality for population-based cancer survival analysis

BackgroundPopulation-based cancer survival is an important measure of the overall effectiveness of cancer care in a population. Population-based cancer registries collect data that enable the estimation of cancer survival. To ensure accurate, consistent and comparable survival estimates, strict control of data quality is required before the survival analyses are carried out. In this paper, we present a basis for data quality control for cancer survival.MethodsWe propose three distinct phases for the quality control. Firstly, each individual variable within a given record is examined to identify departures from the study protocol; secondly, each record is checked and excluded if it is ineligible or logically incoherent for analysis; lastly, the distributions of key characteristics in the whole dataset are examined for their plausibility.ResultsData for patients diagnosed with bladder cancer in England between 1991 and 2010 are used as an example to aid the interpretation of the differences in data quality. The effect of different aspects of data quality on survival estimates is discussed.ConclusionsWe recommend that the results of data quality procedures should be reported together with the findings from survival analysis, to facilitate their interpretation.     

Altruism and antagonistic pleiotropy in Penna ageing model

The Penna ageing model is based on mutation accumulation theory. We show that it also allows for self-organization of antagonistic pleiotropy which helps at young age at the expense of old age. This can be interpreted as emergence of altruism.     

Use of a general model to examine control procedures for a cockroach population

A matrix model for populations is described. The model breaks the population into an appropriate number of stadia to allow for reproductive cycles and includes individual daily survival rates and simple density dependence together with migration. Mortality due to insecticidal treatments may be applied on specified days to simulate space spraying while residual insecticides may be simulated with constant or declining effect. The use of the model is exemplified using a simulated population of Blattella germanica with various treatment regimes. This simulation emphasised the importance of immigration.     

Accelerated failure time (AFT) modeling for the development and survival of Russian wheat aphid, <Emphasis Type="Italic">Diuraphis noxia</Emphasis> (Mordvilko)

Accelerated failure time model (AFT) and Cox’s proportional hazards model (PHM) are considered the two most significant models in survival analysis, which has become a de facto standard for biomedical data analysis and modeling. AFT not only plays an extremely significant role in survival analysis but also finds extensive applications in engineering reliability. Survival analysis studies a special type of random variables: time-to-event (also known as failure time, lifetime or survival time) random variables. Examples of time-to-event random variables include survival times of patients in a clinical trial and failure times of machine components. Since molting and death times of insect individuals are also perfect examples of time-to-event random variables, we argue that survival analysis including AFT modeling is ideal for analyzing insect development and survival data, and further for building dynamic models of insect development and survival. Here we demonstrate such an application with data collected by observing stage-to-stage development and survival of 1,800 Russian wheat aphids (RWA), Diuraphis noxia, reared in laboratory growth chambers arranged in 25 treatments (each with 72 individuals). The main advantages of survival analysis, including the unified modeling of survival and development as well as handling of information censoring, are also discussed.     

ESTABLISHING THE DOSE-DEPENDENT DAILY VARIATIONS OF A LOW MOLECULAR WEIGHT HEPARIN (FRAXIPARINE®) THROUGH A POPULATION APPROACH ANALYSIS IN THE RAT

The effects of dose and dosing time on the anticoagulant activity of a low molecular weight heparin (Fraxiparine®) were studied in rats. Three doses were administered at four evenly spaced dosing times. Rats were kept under a light-dark cycle of 24h, and all the main external factors were constant. The bleeding time, the anti-Xa activity of the drug, and the activated partial thromboplastin time (APTT) were measured. A population approach analysis to assess daily variations was used. With standard methods, interindividual variability may mask potential time-related effects, while the population approach analysis overcomes this difficulty.

Bleeding time was at its peak at 04:00 and at its trough at 22:00, suggesting that platelet activity was time of day dependent. For the pharmacological activity of the drug, we compared several pharmacokinetic models derived from a monocompartmental model. The model that describes the anti-Xa pharmacological activity best is expressed through parameters that depend on animal weight and drug level. The model for APTT is of a sinusoidal type for which the clearance depends on the dosing time. The most interesting result is that the amplitude of this daily variation is linearly dependent on drug level. (Chronobiology International, 17(2), 173–185, 2000)     

Establishing the dose-dependent daily variations of a low molecular weight heparin (Fraxiparine) through a population approach analysis in the rat

The effects of dose and dosing time on the anticoagulant activity of a low molecular weight heparin (Fraxiparine®) were studied in rats. Three doses were administered at four evenly spaced dosing times. Rats were kept under a light-dark cycle of 24h, and all the main external factors were constant. The bleeding time, the anti-Xa activity of the drug, and the activated partial thromboplastin time (APTT) were measured. A population approach analysis to assess daily variations was used. With standard methods, interindividual variability may mask potential time-related effects, while the population approach analysis overcomes this difficulty.

Bleeding time was at its peak at 04:00 and at its trough at 22:00, suggesting that platelet activity was time of day dependent. For the pharmacological activity of the drug, we compared several pharmacokinetic models derived from a monocompartmental model. The model that describes the anti-Xa pharmacological activity best is expressed through parameters that depend on animal weight and drug level. The model for APTT is of a sinusoidal type for which the clearance depends on the dosing time. The most interesting result is that the amplitude of this daily variation is linearly dependent on drug level. (Chronobiology International, 17(2), 173-185, 2000)     

A possible discrepancy between the exposed and the whole population depending on range-size and trap-spacing in vole populations

Population Ecology - From a field study for the vole population (Clethrionomys rufocanus) in Hokkaido in the late summer of 1965, it has been proved that the range length may decrease from 25 to 18...     

A multiple regression method for analysing stage-frequency data

A linear regression method that allows survival rates to vary from stage to stage is described for the analysis of stage-frequency data. It has advantages over previously suggested methods since the calculations are not iterative, and it is not necessary to have independent estimates of stage durations, numbers entering stages, or the rate of entry to stage 1. Simulation is proposed to determine standard errors for estimates of population parameters, and to assess the goodness of fit of models.     

Population dynamics of the japanese clouded apolloParnassius glacialis butler (Lepidoptera: Papilionidae). I. changes in population size and related population parameters for three successive generations

1. Population dynamics of a univoltine butterfly Parnassius glacialis (Lepidoptera: Papilionidae) was studied with mark-recapture methods for three successive generations in a hilly region in Kanazawa City, Ishikawa Prefecture, Japan in 1981–1983.
2. Jolly (1965) andSeber's (1973) method was applied to the mark-recapture data to estimate population parameters (daily survival rate, longevity, population size, sex ratio, etc.).
3. Sampling ratios were at least 50% and 30% for males and females, respectively.
4. Mean daily survival rate for males ranged 0.81–0.86 and that for females 0.80–0.84. Mean longevity was about 4–7 days for the males and about 5 days for the females. Spiders killed more males than females. Maximum longevity for an individual recorded during the study was 31 days for males and 18 days for females.
5. Emergence of the butterflies was later and less synchronous in 1981 than in 1982 and 1983. This was thought to be due to later extinction of heavier snow in 1981 than in the other years.
6. The population remained relatively stable for the three successive generations, with estimated total numbers of 914, 1277, and 869.
7. Estimated sex ratio (% females) was 30–40% at emergence

     

不同玉米品种对截形叶螨种群参数的影响

在室内28±1℃条件下,应用叶盘法研究了中单2号、农大108、赤单202和巴丹3号个不同玉米品种对截形叶螨种群参数的影响.结果表明,在不同品种玉米上,截形叶螨卵期、若螨期、产卵前期、成螨寿命、单雌产卵量、日均产卵量、净增殖率、周限增长率、内禀增长率、世代平均周期和种群加倍时间均有明显差异(P＜0.05);其孵化率为中单2号95.8%、农大108 94.0%、赤单202 90.0%和巴单3号84.0%;幼、若螨期存活率相应地为90.5%、84.0%、86.0%和72.0%;存活曲线均为Ⅰ型.净增殖率在中单2号上最高为41.4,而在巴单3号上最低为16.8;中单2号是其最喜食的品种,其次为农大108,再次为赤单202,对巴单3号的嗜食性最差.     

Short- and long-term effects of winter and spring weather on growth and survival of red deer in Norway

Populations of red deer (Cervus elaphus) in Norway have increased continuously over the last decades. We tested the possible effects of climate and increase in population size on the survival rates and body condition of individuals in one of the northernmost populations of red deer in Europe. Based on 678 individuals of known age marked between 1977 and 1995, we estimated annual survival rates, the probabilities of being harvested and the recapture probability according to sex, age, year, winter and spring weather, population size, and, body weight and body condition, using capture-mark-recapture models. Winter harshness negatively influenced the body weight of yearlings and the survival of calves of both sexes. Spring weather influenced the survival of males in all age classes. A negative trend during the study period was detected in body weight and condition of calves and yearlings, but not in any age- or sex- specific survival rates. No significant gender differences in mean survival were shown in any age class. Moreover, there was little (male) or no (female) detectable between-year variation in survival rates for yearlings and adults. Winter weather acts as a limiting factor on population growth through a short-term effect on first-year survival and a long-term effect on body weight. We discuss the surprising low sex differences in natural survival rates and the differential effects of winter harshness on body weight, body condition and survival in relation to life history characteristics of red deer. Received: 10 November 1997 / Accepted: 2 June 1998     

Establishment, Survival and Activity of the Biocontrol Agents Pichia guilermondii and Bacillus mycoides Applied as a Mixture on Strawberry Plants

Establishment and survival of two biocontrol agents, the yeast Pichia guilermondii isolate Y2, and one of two isolates of the bacterium Bacillus mycoides (B16 and B17), were studied in commercial-like greenhouse experiments. The establishment of the biocontrol agents and their survival on strawberry leaflets and fruitlets were recorded in two experiments. Bacterial populations and their rate of decline over time did not differ significantly when applied alone or in a mixture with the yeast. In most cases, the results were similar for the yeast, but in two out of 27 comparisons the yeast populations, when applied in a mixture with the bacterium, were significantly larger than when applied separately. The biocontrol activity of the yeast and the bacterium against Botrytis cinerea on strawberry plants was examined in two experiments. In one experiment, the biocontrol agents reduced the number of diseased fruits by 50% when applied alone, whereas their mixture resulted in a 75% disease reduction. In this case, the effect of the biocontrol agnets in the mixture was additive. In a second experiment, the same yeast isolate and the other bacterial isolate (B17) were combined. The biocontrol agents did not significantly reduce the disease when applied separately. However, their mixture resulted in a synergistic effect and disease suppression was significantly improved compared to the biocontrol agents applied alone.     

Continuous population estimates forDendroctonus frontalis Zimm. (Coleoptera: Scolytidae) occurring in infestations

Infestations of Dendroctonus frontalisZimm. are often observed to enlarge continuously by the colonization of new hosts in a pattern similar to a forest fire. This pattern of infestation growth presents unique problems in quantitatively estimating populations of D. frontalis. Beetle populations on each infested tree in an infestation go through five processes: attack, oviposition, reemergence, survivorship, and emergence. These processes, which have been described mathematically in the literature, each take several days for completion. In order to follow the distribution and abundance of D. frontalis throughout the course of development of a spot, we need a daily estimate of the number of beetles involved in each process on every tree. Since it is not practical to sample each tree daily, we developed a procedure whereby quantitative estimation procedures for within-tree populations were used in combination with the mathematical models for the life processes to produce a daily record of the number of adults successfully attacking trees, the number of eggs oviposited, the number of beetles reemerging, number of beetles surviving within the trees, and the number of beetles emerging. These daily estimates were then summarized for all trees in the spot for the duration of the infestation. The daily record of populations of D. frontalis, used with information on infestation geometry, were suggested to be of value in describing and elucidating several important facets of population dynamics including dispersal patterns within infestations, between tree beetle loss (mortality), and time lags among the various population processes. The information reported can be used to develop simulation models of population dynamics or to validate existing models.     

秦岭太白红杉种群结构与动态的研究

在秦岭太白山、光头山、玉皇山和冰晶顶等4个地段分别设置了4个样地,用样方法对太白红杉种群进行了调查.共做样方280个.分析了太白红杉的群落学特征、径级结构及其密度变化规律;编制了太白红杉的静态生命表;绘制了存活曲线和死亡曲线;从多角度研究了太白红杉种群的动态变化规律结果表明该种群存活曲线趋向于Deevey-Ⅱ和Ⅲ之间,高径级种群趋向于稳定,低径级种群则反之.幼年个体补充不足,严重影响着该种群的生存和发展.