摘要:

A dynamic model has been developed to quantitate the dynamics of growth ofEscherichia coli. The model integrates the pre-existing models of chromosome replication and cell division by incorporating a description of the synthesis and degradation of ribosomes and protein. Relevant features of the model are: a threshold control for DNA synthesis and a double feedback mechanism that controls ribosome synthesis.

ISSN:0373-4137    

DOI:10.1080/11250007909440291

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A deterministic model is used to describe a typical cell population growth. In particular the Moebs (1977) model has been studied by taking into account the mean “decay” time of one cell in two cells and the ordinary differential equation system of the parameter sensitivity coefficients has been derived. Both the systems have been simultaneously numerically integrated. The results show that the use of the sensitivity coefficient analysis can provide an important standard for the model adequancy and a clearer identification of the biological quantities, which play a major role.

ISSN:0373-4137    

DOI:10.1080/11250007909440292

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

In Lake Santo Parmense, an oligotrophy high-mountain lake in the Northern Apennines, zooplankton is mainly constituted by two species:Eudiaptomus intermediusandDaphnia longispina.

ISSN:0373-4137    

DOI:10.1080/11250007909440293

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An attempt was made to estimate the main demographic parameters in two populations of the tubificids T.tubifexandL. hoffmeisteri. The eggs and worms were counted and the individual weights measured in adequate sub-samples. It was possible to subdivide each population into four groups: eggs and embryos (E), young (G1), young and regressed adults (G2), adults (A), so allowing the adoption of a four compartments model.

ISSN:0373-4137    

DOI:10.1080/11250007909440294

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Density of natural and experimental populations fluctuates. Oscillations may depend either from density-independent mechanisms, or from density-dependent mechanisms.

ISSN:0373-4137    

DOI:10.1080/11250007909440295

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Capacity for increase in 7 species of macrochelid mites is compared with that ofMusca domestica, whose eggs are natural food for these mites.

ISSN:0373-4137    

DOI:10.1080/11250007909440296

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Some recent results on ecology and population dynamics in fresh water filter feeding zooplankton are presented.

ISSN:0373-4137    

DOI:10.1080/11250007909440297

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

In this paper a possible environment is modelled as a chemostat with an input and output flow at a rate v and with a fixed nutrient concentration in the input flow. Three state variables are introduced: the nutrient concentration in the environment and the concentration of two competing species. One species is efficient at low nutrient concentration, the other one at high nutrient concentration. The possibility of coexistence is mathematically proved when a periodic step variation is imposed to the flow v.

ISSN:0373-4137    

DOI:10.1080/11250007909440298

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

This paper is an application of the theory of periodic optimal control to an ecological system. The problem, known as minimum interception problem, consists of finding the periodic control policy which allows a given amount of a main species to be harvested while minimizing the amount intercepted of the secondary species.

ISSN:0373-4137    

DOI:10.1080/11250007909440299

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

The aim of the present study was to analyse the effects of heavy metals (Cd, Zn) on the lifespan and the reproductive activity of a bdelloid speciesPhilodina roseola(Rotifera).

ISSN:0373-4137    

DOI:10.1080/11250007909440300

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor