RESUMO
The correlation between the kinetic stability of molecules against temperature and variations in their geometric structure under optical excitation is investigated by the example of different organic pheromone molecules sensitive to temperature or ultraviolet radiation using the density functional theory. The kinetic stability is determined by the previously developed method based on the calculation of the probability of extension of any structural bond by a value exceeding the limit value LÐ¼Ð°Ñ corresponding to the breaking of the bond under temperature excitation. The kinetic stability calculation only requires the eigenfrequencies and vibrational mode vectors in the molecule ground state to be calculated, without determining the transition states. The weakest bonds in molecules determined by the kinetic stability method are compared with the bond length variations in molecules in the excited state upon absorption of light by a molecule. Good agreement between the results obtained is demonstrated and the difference between them is discussed. The universality of formulations within both approaches used to estimate the stability of different pheromone molecules containing strained cycles and conjugated, double, and single bonds allows these approaches to be applied for studying other molecules. Graphical Abstract Estimation of the thermal and photochemical stabilities of pheromones.
RESUMO
The paper deals with an approach to the description of the age and temporal dynamics of cancer, based on the model describing the dynamics of the age of cancer as a second order phase transition. This approach is widely used for studying physical systems. This model of cancer development as second order phase transitions is in a good agreement with medical statistics. The cancer incidence dynamics is described only with two free parameters, easily verified according to statistics and well interpreted. The applicability of the second order phase transition model for description of a non-physical system defines the universal nature of the processes occurring during phase transitions.
Assuntos
Modelos Estatísticos , Neoplasias/diagnóstico , Neoplasias/epidemiologia , Dinâmica Populacional/estatística & dados numéricos , Adulto , Distribuição por Idade , Fatores Etários , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oriente Médio/epidemiologia , Neoplasias/classificação , Neoplasias/patologia , Federação Russa/epidemiologia , Fatores Sexuais , Estados Unidos/epidemiologiaRESUMO
The analysis is conducted on population dynamics of gypsy moth from different habitats of the South Urals. The pattern of cyclic changes in population density is examined, the assessment of temporal conjugation in time series of gypsy moth population dynamics from separate habitats of the South Urals is carried out, the relationships between population density and weather conditions are studied. Based on the results obtained, a statistical model of gypsy moth population dynamics in the South Urals is designed, and estimations are given of regulatory and modifying factors effects on the population dynamics.