Serious impacts by nonindigenous species often occur via predation. The magnitude of impact is expected to be closely tied to the invading species niche breadth. For predatory impacts, diet breadth should be particularly important. We examined the relationship between a species foraging behaviour and its invasiveness and impact by comparing the feeding behaviour of four Gambusia species, two in...

We derive necessary and sufficient conditions in order for binary voting choices over a finite number of pairs of alternatives to be consistent with voter preferences that admit concave utility representations. These conditions imply simple testable restrictions on the location of voters’ ideal points, and can be used to predict individual voting behavior. On the other hand, if the location of ...

People’s choices can be predicted given information about their preferences. Learning people’s preferences is the inverse problem of inferring preferences from choices. Given the apparent relationship between choice prediction and preference learning, it is natural to ask whether the two are mutually consistent. Given weak assumptions, we show that no single, consistent model of the relationshi...

This paper studies differences in inequality perceptions, distributional norms, and redistributive preferences between East and West Germany. As expected, there are substantial differences with respect to all three of these measures. Surprisingly, however, differences in distributional norms are much smaller than differences with respect to inequality perceptions or redistributive preferences. ...

In allocating goods with no use of monetary transfers, random allocation mechanisms can be designed in order to elicit information on preference intensities. I study the nontransfer allocation of two ex-ante identical objects under Bayesian incentive compatibility, with symmetric agents and independent private valuations. I …nd the ex-ante utilitarian-optimal mechanism, in which the probability...

Among energy-maximizing animals, preferences for different prey can be explained by ranking the prey according to their energetic content. However, diet choice also depends on characteristics of the predator, such as the need to ingest necessary nutrients and the constraints imposed by digestion and toxins in food. In combination, these factors can lead to mixed diets in which the energetically...

The heritability of diet selection for mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb] Beetle) by grazing sheep was estimated from fecal samples collected from 549 Rambouillet ewes. Fecal samples were collected in September and October during 1996 and 1997 from free-grazing ewes on intermountain sagebrush-bunchgrass rangelands at the U.S. Sheep Experiment Station in Idah...

Some of the biggest public health problems in the world are: physical inactivity, sedentary lifestyle, obesity, which are generating non-communicable diseases [4]; these diseases are responsible for six of every ten deaths in the world [5]. One solution to this problem is the gyms, but they are not satisfactory because of its overall vision. This generalization leads to that persons are not con...