Offspring thermal demands and parental brooding efficiency differ for precocial birds living in contrasting climates.

Background: Chicks of precocial birds hatch well-developed and can search actively for food but their homeothermy develops gradually during growth. This makes them dependent on heat provided by parents ("brooding"), which is then traded off against other activities, mainly foraging. Although brooding has been documented in many precocial birds, little is known about the differences in the amount and efficiency of brooding care, brooding diel rhythmicity, and impact on the chick's growth, particularly between species living in different climatic conditions.

Aggressiveness in a subtropical shorebird's nest defense is adjusted to the predator species and shared by conspecifics.

Aggression is an important component of an animal's defense when protecting offspring from predators. Ground nesting birds use a variety of defense strategies. However, their choice according to situation context is poorly known, especially in nonpasserines and in the subtropics and tropics.

Diel timing of nest predation changes across breeding season in a subtropical shorebird.

Predation is the most common cause of nest failure in birds. While nest predation is relatively well studied in general, our knowledge is unevenly distributed across the globe and taxa, with, for example, limited information on shorebirds breeding in subtropics. Importantly, we know fairly little about the timing of predation within a day.

Silicone rubber-hydrogel composites as polymeric biomaterials. VI. Transport properties in the water-swollen state.

Permeation of inorganic salts in water-swollen silicone rubber-hydrogel composites consisting of a silicone rubber matrix and lightly cross-linked particles of poly(2-hydroxyethyl methacrylate), poly(2-hydroxyethyl methacrylate-co-methacrylic acid), poly(methacrylic acid), polyacrylamide or poly(acrylamide-co-methacrylic acid) hydrogels was investigated. The results, together with earlier data on permeation of non-ionic low-molecular-weight substances through the composite materials, were evaluated in terms of the free-volume diffusion theory. It was found that the materials with water content exceeding a certain limit are highly permeable to the salts, and that, as regards permeation properties, they behave as homogeneous water-swollen hydrogels.

Silicone rubber-hydrogel composites as polymeric biomaterials. III. An investigation of phase distribution by scanning electron microscopy.

The structure of silicone rubber-hydrogel composite materials was investigated by scanning electron microscopy (SEM) and light microscopy. The polymer phases in these materials composed of the polysiloxane matrix and very small particles of lightly cross-linked poly(2-hydroxyethylmethacrylate) or poly(2-hydroxyethylmethacrylate-co-methacrylic acid) were visualized using both methods. The distribution of polymer phases was studied by SEM of fracture surfaces of the materials.