Water hardness is a property depending on the presence of alkaline earth metals, mainly calcium and magnesium. Among the strategies for water quality monitoring, ecotoxicological assays are performed to minimize impacts and classify water bodies. For these laboratory evaluations parameters are previously defined in the guidelines, including water hardness for both cultivation and testing medium...

The standard Dynamic Energy Budget (DEB) model assumes that food is converted to reserve and a fraction κ of mobilised reserve of an individual is allocated to somatic maintenance plus growth, while the rest is allocated to maturity maintenance plus maturation (in embryos and juveniles) or reproduction (in adults). The add_my_pet collection of over 300 animal species from most larger phyla, and...

In order to investigate the transmission mechanism of the infectious individual with Ebola virus, we establish an SEIT (susceptible, exposed in the latent period, infectious, and treated/recovery) epidemic model. The basic reproduction number is defined. The mathematical analysis on the existence and stability of the disease-free equilibrium and endemic equilibrium is given. As the applications...

Interspecific interactions can be modulated by the community context in which they occur. In this paper I focus on plant–pollinator interactions and their modulation by introduced herbivores through changes in plant population density. I first develop a mathematical model that relates the population density of an animal-pollinated plant species with pollinator visitation frequency, pollination,...

The paper elaborates on understanding, measuring and optimizing perceived color quality of natural images. We introduce a model for optimal color reproduction of natural scenes which is based on the assumption that color quality of natural images is constrained by perceived naturalness and colorfulness of these images. To verify the model, a few experiments were carried out where subjects estim...

We have analyzed the relations between the mutational pressure, recombination and selection pressure in the bit-string model with sexual reproduction. For specific sets of these parameters we have found three phase transitions with one phase where populations can survive. In this phase, recombination enhances the survival probability. Even if recombination is associated, to some extent, with ad...

backgrand: cotinine (cot) is a major degradation product of nicotine (nic). the participation of leptin in female reproduction is well-established, but any role in male reproductive function is at the best tenuous. objective: the aim of this study was to evaluate the in-vitro effects of nicotine, cotinine and leptin on sperm parameters in normal semen of non-smokers fertile men. materials and m...

We present new mathematical models that include the impact of using selected preventative measures such as insecticide treated nets (ITN) in controlling or ameliorating the spread of the Zika virus. For these models, we derive the basic reproduction number and sharp estimates for the final size relation. We first present a single-stage model which is later extended to a new multistage model for...

Background Male fertility and reproduction can affect by stress. The means by which stress influences reproduction is not clearly understood. The aim of the present study was to examine, using stereological methods, the role of glucocorticoids during chronic restraint stress on spermatogenesis. MaterialsAndMethods Twenty four male adult Sprague- Dawley rats were allocated to four equal groups; ...