5 research outputs found
Predator odours as reproductive inhibitors for Norway rats
We examined the influence of predator odor on reproductive output of Norway rats (Rattus norvegicus). Naive laboratory rats responded to predator chemical cues with reduced litter sire and skewed sex ratio. We found that exposure to predator urine had its greatest effect on implantation and maintenance of implantation when predator urine was applied to the bedding of rats during the first third of gestation. Based on the physical appearance of corpora lutea and uterine implantation scars, we found that the reduction in litter sire was due to resolution of the embryos during the early part of gestation. Subsequently, we discovered that the reduction in litter sizes in rats exposed to predator urine could be attributed to suppressed progesterone levels affecting implantation of embryos. Chronically high corticoslerone levels did not suppress reproductive output. Suppression of reproduction also occurred when rats were exposed to urine of conspecifics housed under high population densities. The evolutionary adaptive response for reduced litter sire is to produce high-quality offspring in an environment where food resources are scarce. The fact that rats respond to certain chemical signals in predator urine in a similar fashion may be fortuitous, and may have more to do with the coincidence that the urine contains similar cues resulting from protein digestion in carnivores and protein catabolism in nutritionally deprived rodents, rather than specific predator-prey adaptations
Cooling-Triggered Release from Mesoporous Poly(N-isopropylacrylamide) Microgels at Physiological Conditions
The formation and development of health-saving competencies of university students
The importance of the presented paper is determined by the fact
that the worldview of Russian society is characterized by the
emergence of awareness of the priority of the value of human health. It
has been proved that the process of developing the health-saving
competency of university students has positive dynamics provided that
modern educational technologies are introduced into programs of
study, namely, socio-psychological training which provides a
concretization of the concept of “health-saving competency of a
specialist”. It includes the implementation of a set of pedagogical
conditions that ensure the effective formation of health-saving
competency of students.La importancia del documento presentado está determinada por
el hecho de que la cosmovisión de la sociedad rusa se caracteriza por
la aparición de la conciencia de la prioridad del valor de la salud
humana. Se ha demostrado que el proceso de desarrollo de la
competencia para el ahorro de la salud de los estudiantes universitarios
tiene una dinámica positiva, siempre que las tecnologías educativas
modernas se introduzcan en los programas de estudio, a saber, la
formación sociopsicológica que proporciona una concreción del
concepto de "ahorro de la salud". Competencia de un especialista "; La
implementación de un conjunto de condiciones pedagógicas que
aseguren la formación efectiva de la competencia de los estudiantes
para salvar la salud