The significance of biparental care in the brown bullhead, Ictalurus nebulosus

Parental care in the brown bullhead is characterized by variation in the participation of each sex. Most broods are attended by both sexes, but some are attended by a male alone, or rarely, a female alone. Two care-givers were more successful than one alone in fostering offspring survival. However, there was no significant difference between two care-givers and one alone in the proportion of time that broods were unattended. Potential brood predators were chased less frequently by one adult alone than by adults aided by their mate. This difference may be unimportant since two adults simultaneously attended their brood only 19% of the time. Males alone attended their broods a significantly greater proportion of time than did either males or females aided by their mates. This difference suggests that males alone sustain a greater cost of care-giving (starvation and therefore reduced future reproduction) than do males aided by their mates. Thus, males alone may more often leave broods (and not return) than males that are aided in care-giving. The differential success observed may be due to a difference in the likelihood that the male (the principal care-giver) leaves the brood permanently, rather than differences in the quality of care one or two adults provide. I suggest that two care-givers are more successful than one because the net benefits of care-giving exceed the net benefits of leaving for males when aided by their mates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42631/1/10641_2004_Article_BF00005153.pd

Pion emission from the T2K replica target: method, results and application

The T2K long-baseline neutrino oscillation experiment in Japan needs precise predictions of the initial neutrino flux. The highest precision can be reached based on detailed measurements of hadron emission from the same target as used by T2K exposed to a proton beam of the same kinetic energy of 30 GeV. The corresponding data were recorded in 2007-2010 by the NA61/SHINE experiment at the CERN SPS using a replica of the T2K graphite target. In this paper details of the experiment, data taking, data analysis method and results from the 2007 pilot run are presented. Furthermore, the application of the NA61/SHINE measurements to the predictions of the T2K initial neutrino flux is described and discussed.Comment: updated version as published by NIM

The parental care behaviour of Paratilapia polleni (Perciformes, Labroidei), a phylogenetically primitive cichlid from Madagascar, with a discussion of the evolution of maternal care in the family Cichlidae

The parental behaviour of the Madagascan cichlid, Paratilapia polleni , was studied in the laboratory. According to current hypotheses of phylogenetic intrarelationship for the family Cichlidae, Paratilapia is a representative of a phylogenetically primitive cichlid lineage, and as such is of particular interest in comparative evolutionary studies. Given the basal phylogenetic placement of Paratilapia it seems reasonable to expect that, if maternal participation in brood care arose within the extant Cichlidae, then the proposed plesiomorphic system of extensive male care of eggs and embryos may be retained in this taxon. This is not the case, and already by the fertilized-egg interval male and female roles in Paratilapia are strongly differentiated with the female as the primary care giver. In addition to specialized behavioural roles, a unique egg morphology and mobile egg mass is described for Paratilapia . The results of the study are discussed in the context of theories of the evolution of maternal brood care within the Cichlidae.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42636/1/10641_2004_Article_BF00004768.pd

G.H. Mead: theorist of the social act

There have been many readings of Mead's work, and this paper proposes yet another: Mead, theorist of the social act. It is argued that Mead's core theory of the social act has been neglected, and that without this theory, the concept of taking the attitude of the other is inexplicable and the contemporary relevance of the concept of the significant symbol is obfuscated. The paper traces the development of the social act out of Dewey's theory of the act. According to Mead, Dewey's theory does not sufficiently account for consciousness. Grappling with this problematic leads Mead to several key ideas, which culminate in his theory of the social act. The social act and taking the attitude of the other are then illustrated by the analysis of a game of football. The interpretation presented has two novel aspects: first, symbolisation arises not simply through self taking the attitude of the other, but through the pairing of this attitude with the complementary attitude in self; second, self is able to take the attitude of the other to the extent that self has in actuality or in imagination previously been in the social position of the other. From this standpoint the key issue is how the attitude of self and other become integrated. New directions for empirical research, aimed at advancing this question are outlined. Finally, the paper shows how the social act can contribute to our contemporary concerns about the nature of the symbolic