Abstract Energetic constraints on precipitation are useful for understanding the response of the hydrological cycle to ongoing climate change, its response to possible geoengi-neering schemes, and the limits on precipitation in very warm climates of the past. Much recent progress has been made

of discrete isochrone sampling as well as to the energetic constraints for a proper normalization of the main sequence vs. post-MS luminosity contribution in simple stellar populations. The case of template models for present-day elliptical galaxies is reviewed in more detail comparing the results from

1. The absolute energy needs of small animals are generally lower than those of larger animals. This should drive higher mortality of larger animals, when the environmental conditions deterio-rate. However, demonstration of the effect of energy constraints on survivals proved difficult, because

ABSTRACT The intertropical convergence zone (ITCZ) has been the focus of considerable research in recent years, with much of this work concerned with how the latitude of maximum tropical precipitation responds to natural climate variability and to radiative forcing. The width of the ITCZ, however, has received little attention despite its importance for regional climate and for understanding the general circulation of the atmosphere. This paper investigates the ITCZ width in simulations with an idealized general circulation model over a wide range of climates. The ITCZ, defined as the tropical region where there is time-mean ascent, displays rich behavior as the climate varies, widening with warming in cool climates, narrowing in temperate climates, and maintaining a relatively constant width in hot climates. The mass and energy budgets of the Hadley circulation are used to derive expressions for the area of the ITCZ relative to the area of the neighboring descent region, and for the sensitivity of the ITCZ area to changes in climate. The ITCZ width depends primarily on four quantities: the net energy input to the tropical atmosphere, the advection of moist static energy by the Hadley circulation, the transport of moist static energy by transient eddies, and the gross moist stability. Different processes are important for the ITCZ width in different climates, with changes in gross moist stability generally having a weak influence relative to the other processes. The results are likely to be useful for analyzing the ITCZ width in complex climate models and for understanding past and future climate change in the tropics.

Using principal component analysis, cyclic coordinate descent, and conjugate gradient minimization, physical conformations of HIV-1 protease were produced that captured the opening and closing motions of the flaps, thus modeling the flexibility of the binding site.

, it is also necessary to introduce suitable regularizations in order to improve the convergence of the reconstruction process toward a reliable solution. In this context, the paper presents a method that exploits an energetic constraint to define a regularization term of the cost functional. A numerical

/or behavioral) costs can be used to determine an energetic optimal size for individuals in such populations. Comparisons of the energetic optimal size to the maximum predicted size based on mechanical constraints, and the ensuing mortality schedule, provides a mechanism to study and explain organism size

Abstract. Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body

in two dimensions of energetics: (i) the absolute, mass-dependent dimension (BMR) and (ii) the relative, mass-independent dimension (MIBMR). The shapes of both relationships were similar and most consistent with that expected from the Energy Constraint Hypothesis, which was proposed previously to explain

was significantly associated with three different measures of predation risk, undermining the idea that they represent anti-predator adaptations. 4. Polyphasic sleep was associated with small body size, shorter sleep cycles and longer sleep durations. The correlation with size may reflect energetic constraints