Continuous Monocyclic and Polycyclic Age Structured Models of Population Dynamics

This paper focuses on the study of continuous age-structured models, or more general, physiologically structured models, which used for detailed and accurate study of population dynamics in many ecological, biological applications and medicine. In contrast to simpler unstructured models, these models allow us to relate the individual life-histories described as fertility and mortality rates of an individual at a given age with population dynamics. Depending from the particularity of reproduction mechanism continuous age-structured models are divided into monocyclic (reproduction occurs only at the one fixed age of individuals) and polycyclic (reproduction occurs with age-dependent probability at some age reproductive window) models. The linear monocyclic age-structured models are used often in cell cycles modelling, in population dynamics of plants, etc. In this case continuous age-structured models allow for obtaining the exact analytical solution. Since the linear and non-linear polycyclic age-structured models are more general then monocyclic models, they coverwider  range of applications in life science. But in this case solution of model can be obtained only in the form of recurrent formulae and can be used only in numerical algorithms. Both solutions obtained in this work allow us to study numerically the important dynamical regimes population outbreaks of three types: oscillations with large magnitude, pulse sequence and single pulse. Thus, analysis of continuous age-structured models of population dynamics provides insight into features and particularities of complex dynamical regimes of populations in many applications in biology, ecology and medicine

Kl3γ+K^+_{l3\gamma} decays revisited: branching ratios and T-odd momenta correlations

We calculate the branching ratios of the $K^+ \to \pi^0 l^+ \nu_l\gamma (l = e, \mu)$ decays, and the T-odd triple momenta correlations $\xi=\vec{q}\cdot[\vec{p}_l \times \vec{p}_\pi]/M^3_K$, due to the electromagnetic final state interaction, in these processes. The contributions on the order of $\omega^{-1}$ and $\omega^0$ to the corresponding amplitudes are treated exactly. For the branching ratios, the corrections on the order of $\omega$ are estimated and demonstrated to be small. We compare the results with those of other authors. In some cases our results differ considerably from the previous ones.Comment: 13 pages, 11 figures; references adde

Development of Regional Maximum Permissible Concentrations of Oil, Lead, Chromium, Nickel, and Copper in the Ordinary Black Soils of Central Ciscaucasia

Contamination of ordinary chernozems of the Central Ciscaucasia with oil, lead, chromium, nickel and copper leads to a deterioration in their biological indicators. A significant decrease in the number of microflora, enzymatic activity and inhibition of the state of plants was established. The ecotoxicity sequence of heavy metals for ordinary black soils of Central Ciscaucasia is the following: Cr > Pb ≥Cu ≥ Ni. Ordinary black soils of Central Ciscaucasia, compared to similar black soils of Western Ciscaucasia, are somewhat less resistant to pollution with chromium, but are more resistant to pollution with copper and nickel. Resistance to pollution with lead and oil is the same. Regional maximum permissible concentrations of oil, lead, chromium, nickel and copper have been set for ordinary black soils of Central Ciscaucasia, based on disruptions of the environmental and the agricultural functions of the soil

Another Majorana Idea: Real and Imaginary in the Weinberg Theory

The Majorana discernment of neutrality is applied to the solutions of $j=1$ Weinberg equations in the $(j,0)\oplus (0,j)$ representation of the Poincar\`e group.Comment: ReVTeX file, 6pp., no figure

The changes of the tubular epithelium phenotype in the contralateral kidney nephrons while developing unilateral ureteral obstruction: an experimental study

Introduction. The high prevalence of renal diseases caused by urinary tract obstruction led to the need for experimental research of compensatory and pathological processes with kidney injury. It is also of relevance to study key mechanisms providing a compensatory function of the contralateral kidney for early diagnosis, treatment, and prognosis of obstructive renal diseases.Purpose of the study. To examine epithelial nephron cells phenotype dynamics changes in contralateral kidney using unilateral ureteral obstruction experimental model.Materials and methods. Model of unilateral ureteral obstruction was established using adult rabbits. The studies were carried out on days 7, 14 and 21 of complete obstruction of the left ureter. Immunophenotyping was performed on contralateral kidney tissue samples using epithelial (cytokeratin 7, E-cadherin) and mesenchymal (vimentin, α-smooth muscle actin) markers.Results. The contralateral kidney under additional load can maintain the morphological and functional characteristics of the nephron for a long time. The first transmogrify signs in the nephron epithelium phenotype were detected by day 21 as the diffuse appearance of mesenchymal marker vimentin with unaltered visualization of epithelial phenotype markers.Conclusion. The results obtained allow us to assume that the compensatory reserve of the contralateral kidney is gradually decreasing when the duration of the obstruction increases. Thus, the likelihood of developing negative disorders increases

Measurement of the K+→μ+νμγK^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma} decay form factors in the OKA experiment

A precise measurement of the vector and axial-vector form factors difference $F_V-F_A$ in the $K^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma}$ decay is presented. About 95K events of $K^+\rightarrow{\mu^+}{\nu_{\mu}}{\gamma}$ are selected in the OKA experiment. The result is $F_V-F_A=0.134\pm0.021(stat)\pm0.027(syst)$. Both errors are smaller than in the previous $F_V-F_A$ measurements.Comment: 9 pages, 8 figure