Evolutionary conflicts of interest between family members are expected to influence patterns of parental investment. In altricial birds, despite providing the same kind of parental care, patterns of investment in different offspring can differ between parents, a situation termed parentally biased favoritism. Previous explanations for parentally biased favoritism have received mixed theoretical ...

Despite a massive research effort, our understanding of why, in most vertebrates, males compete for mates and females care for offspring remains incomplete. Two alternative hypotheses have been proposed to explain the direction of causality between parental care and sexual selection. Traditionally, sexual selection has been explained as a consequence of relative parental investment, where the s...

Males play a variable parental role in reproduction, ranging from no male parental care to extensive male care. Females may acquire either direct or indirect fitness benefits from their mate choice, and direct fitness benefits include male parental care. Theoreticians have traditionally emphasized direct fitness benefits to females in species with extensive male parental care. We review the lit...

Male androgen responses to social challenges have been predicted to vary with mating system, male-male aggressiveness, and the degree of paternal investment in birds ("challenge hypothesis," Am. Nat. 136 (1990), 829). This study focused on the interspecific predictions of the challenge hypothesis. Comparative methods were used to control for effects of the phylogenetic relatedness among the sam...

The process of photopolymer stereo-lithography (SLA) provides a unique opportunity for the rapid prototyping of investment castings having both high surface quality and complex geometry from both ferrous and non-ferrous metals. A specific internal honeycomb structure gives a combination of high pattern stiffness needed for precise replication of geometry by investment shell molds with an extrem...

When environmental conditions vary stochastically, individuals accrue fitness benefits by exhibiting phenotypic plasticity. Here we analyze a general dynamic-programming model describing an individual's optimal energy allocation in a stochastic environment. After maturation, individuals repeatedly decide how to allocate incoming energy between reproduction and maintenance. We analyze the optima...

Predictability of financial time series (FTS) is a well-known dilemma. A typical approach to this problem is to apply a regression model, built on the historical data and then further extend it into the future. If however the goal is to support or even make investment decisions, regression-based FTS predictions are inappropriate as on top of being uncertain and unnecessarily complex, they requi...

The investment decisions of small‐scale farmers in developing countries are conditioned by their financial environment. Binding credit market constraints and incomplete insurance can reduce investment in activities with high expected profits. We conducted several experiments in northern Ghana in which farmers were randomly assigned to receive cash grants, grants of or opportunities to purchase ...

Using a newly constructed data set, we compare sources of funds and investment strategies of venture capital (VC) funds in Germany, Israel, Japan and the UK. Sources of VC funds differ significantly across countries, e.g. banks are particularly important in Germany, corporations in Israel, insurance companies in Japan, and pension funds in the UK. VC investment patterns also differ across count...