Italian ryegrass (Lolium multiflorum L.) is a highly competitive weed widely disseminated worldwide that affects both summer and winter crops. The development of predictive emergence models can contribute to optimizing management. aim this study was develop validate an empirical model based on soil thermal time. For development, cumulative in two locations obtained, the validated with data coll...

The Gompertz distribution has many applications, particularly in medical and actuarial studies. However, there has been little recent work on the Gompertz in comparison with its early investigation. The problem of analyzing and estimating parameters of bivariate Gompertz distribution with shared frailty is of interest and the focus of this paper. We propose maximum likelihood estimation procedu...

The critical period for weed control (CPWC) is the period in the crop growth cycle during which weeds must be controlled to prevent unacceptable yield losses. Field studies were conducted in 2005 and 2006 in the University of Birjand at the south east of Iran to determine CPWC of corn using a randomized complete block design with 14 treatments and four replications. The treatments consisted of ...

the effect of weeds on yield of plants is variable during the plant growing periods. recognition of these critical periods is basically important for weed control. the gompertz and logistic are two mathematical models, which are suitable to study the presence of weed effect on the yield of plants. the main problem of using these models is calibration. in this study, a method is developed for mo...

Toxicity testing in populations probe for responses in demographic variables to anthropromorphic or natural chemical changes in the environment. Importantly, these tests are performed on species in isolation of adjacent tropic levels in their ecosystem. The development and validation of coupled species models may aid in predicting adverse outcomes at the ecosystems level. Here, we aim to valida...

This work is about the Gompertz-Makeham distribution. The distribution has been applied plenty of times. The properties of the Gompertz-Makeham distribution investigated in this work are unimodality of the Gompertz-Makeham distribution and relationship between the median value and the mean residual life time of the Gompertz-Makeham distribution. For most of the realistic set of parameter values...

This study investigated, for the first time, age and growth of spotted lanternfish Myctophum punctatum through an analysis otolith microstructure. A total 377 individuals were collected from Strait Messina (central Mediterranean Sea), ranging between 20.3 73.7 mm standard length. Their length–weight relationship was estimated, these outputs indicated isometric growth, all specimens when males f...

Gompertz curve has been used to estimate the number of residual faults in testing phases of software development, especially by Japanese software development companies. Since the Gompertz curve is a deterministic function, the curve cannot be applied to estimating software reliability which is the probability that software system does not fail in a prefixed time period. In this article, we prop...

Using a first-order model to describe ruminal in situ digestion implies that the rate of digestion is affected only by the quantity of potentially digestible substrate remaining. Other factors, like the microbial efficacy for digesting substrate, are assumed to be constant. However, microbes are not only the cause but also the result of digestion, being one of the digestion end-products. Two si...