Smoothed and Iterated Bootstrap Confidence Regions for Parameter Vectors

The construction of confidence regions for parameter vectors is a difficult problem in the nonparametric setting, particularly when the sample size is not large. The bootstrap has shown promise in solving this problem, but empirical evidence often indicates that some bootstrap methods have difficulty in maintaining the correct coverage probability, while other methods may be unstable, often resulting in very large confidence regions. One way to improve the performance of a bootstrap confidence region is to restrict the shape of the region in such a way that the error term of an expansion is as small an order as possible. To some extent, this can be achieved by using the bootstrap to construct an ellipsoidal confidence region. This paper studies the effect of using the smoothed and iterated bootstrap methods to construct an ellipsoidal confidence region for a parameter vector. The smoothed estimate is based on a multivariate kernel density estimator. This paper establishes a bandwidth matrix for the smoothed bootstrap procedure that reduces the asymptotic coverage error of the bootstrap percentile method ellipsoidal confidence region. We also provide an analytical adjustment to the nominal level to reduce the computational cost of the iterated bootstrap method. Simulations demonstrate that the methods can be successfully applied in practice

Social rank overrides environmental and community fluctuations in determining meat access by female chimpanzees in the Taï National Park, Côte d’Ivoire

Meat, long hypothesized as an important food source in human evolution, is still a substantial component of the modern human diet, with some humans relying entirely on meat during certain times of the year. Understanding the socio-ecological context leading to the successful acquisition and consumption of meat by chimpanzees (Pan troglodytes), our closest living relative, can provide insight into the emergence of this trait because humans and chimpanzees are unusual among primates in that they both (i) hunt mammalian prey, (ii) share meat with community members, and (iii) form long-term relationships and complex social hierarchies within their communities. However, females in both human hunter-gatherer societies as well as chimpanzee groups rarely hunt, instead typically accessing meat via males that share meat with group members. In general, female chimpanzee dominance rank affects feeding competition, but so far, the effect of female dominance rank on meat access found different results within and across studied chimpanzee groups. Here we contribute to the debate on how female rank influences meat access while controlling for several socio-ecological variables. Multivariate analyses of 773 separate meat-eating events collected over more than 25 years from two chimpanzee communities located in the Taï National Park, Côte d’Ivoire, were used to test the importance of female dominance rank for being present at, and for acquiring meat, during meat-eating events. We found that high-ranking females were more likely to be present during a meat-eating event and, in addition, were more likely to eat meat compared to the subordinates. These findings were robust to both large demographic changes (decrease of community size) and seasonal ecological changes (fruit abundance dynamics). In addition to social rank, we found that other female properties had a positive influence on presence to meat-eating events and access to meat given presence, including oestrus status, nursing of a small infant, and age. Similar to findings in other chimpanzee populations, our results suggest that females reliably acquire meat over their lifetime despite rarely being active hunters. The implication of this study supports the hypothesis that dominance rank is an important female chimpanzee property conferring benefits for the high-ranking females

Taylor v. Illinois: Supreme Court Approves Preclusion of Defense Witnesses for Discovery Violation

In Taylor v. Illinois, the United States Supreme Court held that preclusion of defense witnesses for discovery violations is not absolutely prohibited by the Compulsory Process Clause of the Sixth Amendment. This Note analyzes the Court\u27s reasoning in the context of past Supreme Court decisions on the Compulsory Process guarantees. The analysis reveals that the Court\u27s decision has substantial shortcomings. Holding that the compulsory process does not absolutely bar the preclusion sanction implies that under some circumstances compulsory process does bar the preclusion sanction, necessitating a balancing test. The test purportedly adopted by the Court is cast in such vague terms that it cannot help resolve the harder cases. In conclusion, the Court\u27s decision leaves the law relatively unchanged. The holding has little impact because few courts have held to the contrary. Moreover, the court\u27s equivocation provides little guidance to the lower courts for determining under what circumstances compulsory process would bar the preclusion sanction

Aristotle\u27s Demarcation of the Senses of Energeia in Metaphysics IX,6

Aristotle demarcates in Metaphysics IX.6 three most crucial senses of energeia. There is that which pertains to categorial being, and that which pertains to becoming. Finally, there is energeia involved in the cognitive and affective lives of animals

Plato’s \u3cem\u3eTheaetetus \u3c/em\u3e as Dialectic

Editor\u27s note: After blind peer review, this paper was selected for reading at the University of Dayton\u27s 10th annual Philosophy Colloquium, held Feb. 27-28, 1981. Plato\u27s Theaetetus, having episteme (knowledge or science) as its principal topic, attracts considerable interest. Two lines of interpretation dominate the literature. Each provides a way for explaining the two most prominent features of the dialogue — that it fails to define knowledge and that Socrates refrains from introducing the forms to help himself out. The majority of commentators, adhering to the standard view of Plato — that he has a doctrine of forms which he retains throughout his career, or once discovering never forsakes — think that the Theaetetus, since it does not appeal to the forms as the necessary objects of knowledge, shows their very necessity by its consequent failure to define knowledge. The Theaetetus, for them, offers an indirect proof that without the forms, Plato cannot give any account of what knowledge is. What this view sometimes assumes is that in other dialogues into which the forms enter, such as Republic or Sophist, there is a complete account. The Theaetetus, then, confirms the earlier treatments of knowledge, say in the Republic, or prepares for the answer coming in the Sophist