Carnapian inductive logic for Markov chains

Carnap's Inductive Logic, like most philosophical discussions of induction, is designed for the case of independent trials. To take account of periodicities, and more generally of order, the account must be extended. From both a physical and a probabilistic point of view, the first and fundamental step is to extend Carnap's inductive logic to the case of finite Markov chains. Kuipers (1988) and Martin (1967) suggest a natural way in which this can be done. The probabilistic character of Carnapian inductive logic(s) for Markov chains and their relationship to Carnap's inductive logic(s) is discussed at various levels of Bayesian analysis.     

Serotonin Depletion Does Not Prevent Intrinsic Sensitization in the Leech

Intrinsic sensitization is a form of behavioral facilitation that is distinct from the extrinsic sensitization normally studied. To examine whether intrinsic and extrinsic sensitization are mediated by different physiological processes, the effects of 5,7-dihydroxytryptamine-induced serotonin (5-HT) depletion on intrinsic sensitization of the leech whole-body shortening response were observed. Previous experiments have shown that 5-HT depletion disrupts dishabituation and extrinsic sensitization of this behavior in the leech. Intrinsic sensitization was observed in preparations from both control and 5-HT-depleted animals, indicating that this form of behavioral facilitation was not affected by 5-HT depletion. The differences in the effects of 5-HT depletion on intrinsic versus extrinsic sensitization suggest that there are distinct neurophysiological processes mediating these two forms of behavioral facilitation. In addition, 5-HT depletion appeared to disrupt a putative extrinsic form of habituation of the shortening reflex. These data support the hypothesis that both intrinsic and extrinsic processes of neuromodulation mediate habituation and sensitization.     

Anxiety Symptomatology in Mexican-American Adolescents

Mexican-American adults and adolescents in general have been reported to have high levels of anxiety symptomatology. In our study of a tri-ethnic sample of 2528 junior and senior high school students, the Youth Self Report (YSR) version of the Child Behavior Checklist (CBCL) and a sociodemographic questionnaire was used to assess the anxiety symptoms of Hispanic youth. We compared the ratings on anxiety symptoms, using Achenbach's anxiety subscale on the YSR, between two populations. The anxiety levels of youth in coastal southeast Texas (Galveston County) were compared to the anxiety levels of youth in the lower Rio Grande Valley. We found that Mexican-Americans of the Lower Rio Grande Valley scored higher on anxiety symptoms than the tri-ethnic population of Galveston County. Other factors associated with higher anxiety scores for Mexican-American youths included being born outside the US, linguistic fluency, father absent from the home, mother's education, and household size. Multiple regression analyses showed that socio-economic status (SES), family composition, and linguistic fluency had a greater relative impact on anxiety symptomatology than all other factors, both for the total sample as well as for the Mexican-American sample. These results parallel previous findings, with Mexican-American adults, which suggest either higher risk for anxiety symptomatology or a culturally related bias in the reporting of such symptoms.     

Gossip as a Burdened Virtue

Gossip is often serious business, not idle chitchat. Gossip allows those oppressed to privately name their oppressors as a warning to others. Of course, gossip can be in error. The speaker may be lying or merely have lacked sufficient evidence. Bias can also make those who hear the gossip more or less likely to believe the gossip. By examining the social functions of gossip and considering the differences in power dynamics in which gossip can occur, we contend that gossip may be not only permissible but virtuous, both as the only reasonable recourse available and as a means of resistance against oppression.