Categoricity Theorems and Conceptions of Set

Two models of second-order ZFC need not be isomorphic to each other, but at least one is isomorphic to an initial segment of the other. The situation is subtler for impure set theory, but Vann McGee has recently proved a categoricity result for second-order ZFCU plus the axiom that the urelements form a set. Two models of this theory with the same universe of discourse need not be isomorphic to each other, but the pure sets of one are isomorphic to the pure sets of the other.This paper argues that similar results obtain for considerably weaker second-order axiomatizations of impure set theory that are in line with two different conceptions of set, the iterative conception and the limitation of size doctrine.     

Mental maps in memory retrieval and comprehension.

How do people use spatial information stored in maps? This question has been explored in a number of domains, such as memory and language comprehension, with differing results. Some studies of how experimentally learned maps are organised in memory, using primed recognition, have found temporal information to influence mental map organisation. In contrast, studies of narrative comprehension, using probe identification and anaphoric reading times, have observed spatial effects. This study combines these two research traditions and shows that the organisation observed in long-term memory differs from the organisation in narrative comprehension, even when both tasks refer to the same map.     

The Role of School-based Group Mentoring in Promoting Resilience among Vulnerable High School Students

This study examined the role of participation in a year-long school-based group mentoring program, Project Arrive (PA), on increasing resilience during the first year of high school among students identified as being at high risk for school dropout. Participants were 114, ninth grade students taking part in one of 32 PA mentoring groups, and 71 statistically matched comparison students (53% male, 75% eligible for free/reduced-price lunch, 62% Latinx). Using a propensity score with inverse probability of treatment weighting (IPTW) to reduce selection bias, and a multi-level model to account for non-independence of data within mentoring groups, we examined changes from pre-test to program exit on seven external resilience resources (developmental supports and opportunities) and four internal resilience assets (personal strengths). At program exit, PA participants had higher adjusted means than comparisons on six external resources, including school support, school belonging, school meaningful participation, peer caring relationships, prosocial peers, and home meaningful participation. PA participants also had higher adjusted means on one internal asset, problem solving. Results point to the promise of group mentoring as an approach for increasing resilience among academically vulnerable adolescents.     

Color and intensity discrimination in <Emphasis Type="Italic">Xenopus laevis</Emphasis> tadpoles

Investigations into the physiology of Xenopus laevis have the potential to greatly accelerate biomedical research, especially concerning neural plasticity and sensory systems, but are limited by the lack of available information on behavioral learning in this species. Here, we attempt to lay the foundations for a behavioral assay in Xenopus that can be used in conjunction with biological manipulations. We tested cohorts of Xenopus tadpoles across four light-mediated active-avoidance experiments, using either wavelength or intensity as the salient discriminative cue. In the wavelength task, we determine a baseline learning rate and characterize retention of learning, identifying active extinction effects as far more potent than the passage of time in the loss of behavior. In the intensity task, we examine the effects of varying differences between the discriminative stimuli on acquisition and extinction and identify a critical range of intensity differences where learning changes. The results of our experiments demonstrate that Xenopus is a tractable model organism for cognitive research and can learn a variety of associative tasks in the laboratory settings. These data reveal new aspects of the Xenopus larval visual processing system and facilitate future research between cognitive methods and biological/chemical manipulations to study mechanisms of brain structure and function.     

Mother's marital satisfaction associated with the quality of mother‐father‐child triadic interaction

Low marital satisfaction has been shown to be a risk factor for early parenthood and parent‐child relationship problems (Erel & Burman, 1995 ; McHale, 1995 ). The aim of this study was to assess how parental reports of marital satisfaction related to family alliance and coordination in the observed triadic interaction. The study group included 120 families. Marital satisfaction was evaluated during pregnancy, at 4 months, and at 18 months using the Revised Dyadic Adjustment Scale (RDAS; Busby, Christensen, Crane & Larsson, 1995 ) for both parents. Mother‐father‐child interaction was analyzed in the Lausanne Triadic Play setting and coded using the Family Alliance Assessment Scale (Favez, Lavanchy Scaiola, Tissot, Darwiche & Frascarolo, 2011 ) when the child reached 18 months of age. The mother's higher marital satisfaction at every measuring point was associated with a cooperative family alliance and/or higher family coordination at 18 months. The father's experience of marital satisfaction was not related to family interaction at any assessment point. Our study suggests that a mother's experience of lower marital satisfaction during pregnancy may be an early sign of later problems in family relationships.