Hot-blooded singers: endothermy facilitates crepuscular signaling in African platypleurine cicadas (Hemiptera: Cicadidae:<Emphasis Type="Italic"> Platypleura</Emphasis> spp.)

The cicada genus Platypleura has a wide distribution across Africa and southern Asia. We describe endothermic thermoregulation in four South African species that show crepuscular signaling behavior. This is the first evidence of thermoregulation in platypleurine cicadas. Field measurements of body temperature ( T _b) show that these animals regulate T _b through endogenous heat production. Maximum T _b measured was 22.1°C above ambient temperature during calling activity at dusk. The mean T _b during dusk activity did not differ from the mean T _b during diurnal activity. A unique behavior for cicadas, a temperature-dependent telescoping pulsation of the abdomen, was observed in the laboratory during endogenous warm-up. This behavior is part of a unique method of heat generation in endothermic cicadas. Males generally call from trunks and branches within the canopy and appear to use endothermy even when the sun is available to elevate T _b. Endothermy may provide the cicadas with the advantage of decreasing predation and acoustic competition by permitting calling from perches that most complement their cryptic coloration patterns and that ectotherms cannot use due to thermal constraints. In addition, endothermy may permit calling activity during crepuscular hours when atmospheric conditions are optimal for acoustic communication and predation risks are minimal.     

Cultivated cells from mid-trimester amniotic fluids. IV. Cell type identification via one and two-dimensional electrophoresis of clonal whole cell homogenates

Clones of cultivated amniotic fluid cells that have distinct morphologic and growth characteristics (F, AF and E-type) were examined by one-dimensional SDS polyacrylamide gel electrophoresis (SDS-PAGE) and by two-dimensional electrophoresis employing isoelectric focusing and SDS-PAGE (IEF-PAGE). No qualitative differences in band pattern were observed in SDS-PAGE between the various amniotic fluid cell types, but consistent quantitative differences in the ratios of four bands of presumed filamentous proteins provided good distinction between amniotic fluid cells and postnatal skin fibroblast-like cells. By adding separation on the basis of electrical charge to that of molecular size (IEF-PAGE), we observed reproducible qualitative differences in the protein spot patterns between F and both AF and E-type amniotic fluid cells. At least eight discrete proteins appear not to be synthesized by prenatal F-type cells in comparison with their isogenic AF and E counterparts under identical culture conditions. The two-dimensional electrophoretic patterns thus confirm that F and AF amniotic cells, in spite of their morphologic and growth kinetic similarities, are developmentally distinct cell types that retain their differentiated states in culture.     

Federal Decentralization and Adaptive Management of Water Resources: Reservoir Reallocation by the U.S. Army Corps of Engineers

Reservoir operations must respond to changing conditions, such as climate, water demand, regulations, and sedimentation. The U.S. Army Corps of Engineers (Corps) can reallocate reservoir storage to respond to such changes. We assembled and analyzed a database of reservoir reallocations implemented and proposed by the Corps. While only a small portion of total reservoir storage nationwide has been reallocated, there are substantial differences in reallocation frequency and magnitude across the nation: some Corps Districts and Divisions use reallocation while others do not, relying more on discretion and small‐scale adaptation of operations. This difference illustrates how water resource agencies like the Corps decentralize management decisions to allow responding to disparate conditions. Decentralized decision‐making provides a responsive approach to water management, while centralized and hierarchical decision‐making is a slower, more deliberative approach. Decentralized decision‐making may lead to the accumulation of short‐term, local decisions over time to the point that the system is managed differently than anticipated. Reallocation, which is a form of planned adaptive management, can be accommodating of multiple competing demands and different stakeholders, yet expensive and less temporally responsive. The challenge for any large water resource management agency is to balance between local‐level, responsive discretion vs. centralized, planned decision‐making.     

Insectivorous birds consume an estimated 400–500 million tons of prey annually

In this paper, we present an estimate of the predation impact of the global population of insectivorous birds based on 103 (for the most part) published studies of prey consumption (kg ha^?1 season^?1) of insectivorous birds in seven biome types. By extrapolation—taking into account the global land cover of the various biomes—an estimate of the annual prey consumption of the world’s insectivorous birds was obtained. We estimate the prey biomass consumed by the world’s insectivorous birds to be somewhere between 400 and 500 million metric tons year^?1, but most likely at the lower end of this range (corresponding to an energy consumption of ≈?2.7?×?10¹⁸ J year^?1 or ≈?0.15% of the global terrestrial net primary production). Birds in forests account for >?70% of the global annual prey consumption of insectivorous birds (≥?300 million tons year^?1), whereas birds in other biomes (savannas and grasslands, croplands, deserts, and Arctic tundra) are less significant contributors (≥?100 million tons year^?1). Especially during the breeding season, when adult birds feed their nestlings protein-rich prey, large numbers of herbivorous insects (i.e., primarily in the orders Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, and Orthoptera) supplemented by spiders are captured. The estimates presented in this paper emphasize the ecological and economic importance of insectivorous birds in suppressing potentially harmful insect pests on a global scale—especially in forested areas.