Asbestos is a potent carcinogen associated with malignant mesothelioma and lung cancer but its carcinogenic mechanisms are still poorly understood. Asbestos toxicity is ascribed to its particular physico-chemical characteristics, and one of them is the presence of and ability to adsorb iron, which may cause an alteration of iron homeostasis in the tissue. This observational study reports a comb...

Abstract. In this paper we have considered a nonautonomous predator-prey model with time delay due to gestation, in which a disease that can be transmitted by contact spreads among the prey only. Here, we have established some sufficient conditions on the permanence of the system by using inequality analytical technique. By Lyapunov functional method, we have also obtained some sufficient condi...

Two experiments systematically examined factors that influence infants' manual search for hidden objects (N=96). Experiment 1 used a new procedure to assess infants' search for partially versus totally occluded objects. Results showed that 8.75-month-old infants solved partial occlusions by removing the occluder and uncovering the object, but these same infants failed to use this skill on total...

Dogs were tested for object permanence using an invisible displacement in which an object was hidden in one of two containers at either end of a beam and the beam was rotated. Consistent with earlier research, when the beam was rotated 180 degrees , the dogs failed to find the object. However, when the beam was rotated only 90 degrees , they were successful. Furthermore, when the dogs were led ...

In this paper we consider one-predator-two-prey population dynamics described by a control system. We study and compare conditions for permanence of the system for three types of predator feeding behaviors: (i) specialized feeding on the more profitable prey type, (ii) generalized feeding on both prey types, and (iii) optimal foraging behavior. We show that the region of parameter space leading...

A study was conducted in two selected areas of the Brazilian cerrado using Landsat imagery during a five years period (1996-2000), to address the following estimation issues: (1) burnt area using statistical sample techniques; (2) burnt scars permanence; and (3) recurrence of biomass burning. Regarding the burnt area estimates, a decrease of approximately 60% was observed during the period and ...

Combined with all density-dependent factors, the per capita growth rate of a species may be nonmonotonic. One important consequence is that species may suffer from weak Allee effects or strong Allee effects. In this paper, we study the permanence of a discrete-time two-species-interaction model with non-monotonic per capita growth rates for the first time. By using the average Lyapunov function...

This paper investigates the dynamics of a competitive single-prey n-predators model of integrated pest management, which is subject to periodic and impulsive controls, from the viewpoint of finding sufficient conditions for the extinction of prey and for prey and predator permanence. The per capita death rates of prey due to predation are given in abstract, unspecified forms, which encompass la...

and Applied Analysis 3 To the best of the authors’ knowledge, for the nonautonomous case of predatorprey systems with two predators which consume immature prey and stage structure for prey, whether one could obtain the sufficient and necessary conditions which insure the permanence of the system or not is still an open problem. The aim of this paper is, by further developing the analysis techni...

This cohort study included 254 adult patients who used a urinary catheter (UC) during their hospitalization in a university hospital ward. The following were evaluated: catheter use, indication, time of permanence, urinary infection density, mortality, and hospital stay. Throughout the studied period, 14% of the hospitalized patients received UC, totaling 1735 UC-day. In 23% of cases, the proce...