Hampshire College

About: Hampshire College is a education organization based out in Amherst Center, Massachusetts, United States. It is known for research contribution in the topics: Genetic programming & Population. The organization has 461 authors who have published 998 publications receiving 40827 citations.

The Effect of Chemosterilization on Sex Steroid Production in Male Sea Lampreys

Abstract: The sterile male release technique (SMRT) is currently used as part of an integrated effort to control Great Lakes populations of sea lampreys Petromyzon marinus, yet the effects of chemosterilization on the reproductive endocrinology of the sea lamprey are unknown. Male sea lampreys were chemosterilized with bisazir (P, P-bis(1-aziridinyl)-N-methylphosphinothioic amide) and given timed-release implants containing lamprey d-Arg(6)-GnRH I (where GnRH is an acronym for gonadotropin-releasing hormone) and lamprey d-Arg(6)-GnRH III. The effects of chemosterilization on the reproductive endocrine system were evaluated by measuring plasma concentrations of 17β-estradiol (E2) and 15α-hydroxytestosterone (15α-T) with radioimmunoassays. The effectiveness of the implants was evaluated by measuring plasma concentrations of steroids and determining the duration of steroidal responses. The E2 and 15α-T response profiles showed no difference between sterilized and untreated male sea lampreys (P = 0.53). Peak c...

Tags and the Evolution of Cooperation in Complex Environments.

Abstract: Cooperation in evolving populations of agents has been explained as arising from kin selection, reciprocity during repeated interactions, and indirect reciprocity through agent reputations. All of these mechanisms require signican t agent capabilities, but recent research using computational models has shown that arbitrary markers called \tags" can be used to achieve signican t levels of cooperation even in the absence of memory, repeated interactions or knowledge of kin. This is important because it helps to explain the evolution of cooperation in organisms with limited cognitive capabilities, and also because it may help us to engineer cooperative behaviors in multi-agent systems. The computational models used in previous studies, however, have typically been constrained such that cooperation is the only viable strategy for gaining an evolutionary advantage. Here we show that tagmediated recognition can lead to signican t levels of cooperation in a less constrained articial life simulation, even when other viable survival strategies exist. The results suggest that tags provide a simple yet eectiv e mechanism for promoting the emergence of collective behaviors in evolving agent populations.

Schrödinger's Cat and the Ethnography of Law

Abstract: Drawing on research regarding undocumented immigration and transnational adoption, this essay argues that legal and ethnographic accounts retroactively instantiate potential realities that were there all along but are only made visible by official recognition. In this sense, the “field” that is at the center of ethnographic inquiry is brought into being by the activities of the ethnographer, just as the field of (un)documented bodies is brought into being by a judicial decree. At the same time, such authorizations of the real are haunted by the noise that is left behind. This noise makes itself known by its pull on official representations, pointing to the instability of our objects of study, the multidimensionality of everyday life, and the gaps and disjunctions that compel us to return to what was overlooked in order to make our ethnographies real.

Continuous distributions arising from the Three Gap Theorem

Abstract: The well-known Three Gap Theorem states that there are at most three gap sizes in the sequence of fractional parts {αn}n