Thermal shock resistance of brittle ceramic materials with embedded elliptical cracks

An analytical model is established for the prediction of the thermal shock resistance of a ceramic plate with an embedded elliptical crack with ideal thermal insulation. The thermal stress intensity factors at the crack fronts are formulated by fitting the thermal stress to a polynomial form in an un-cracked plate. The thermal shock resistance of sapphire ceramic is evaluated as an example. In addition, the numerical solution of thermal shock resistance suitable for practical engineering applications is provided. The model developed applies to any brittle material in high temperature applications.     

Behavioral momentum: the effects of the temporal separation of rates of reinforcement.

In Part 1 of the experiment, rats responded under a variable-interval (VI) 30-s schedule and a VI 120-s schedule, with each in effect for a block of consecutive sessions. That is, the two VI schedules were presented in successive conditions. In Part 2 the VI schedules alternated each day, and in Part 3 the schedules alternated within the session as a multiple schedule. For half of the rats in Parts 1 and 2, the VI schedule alternated every few minutes within the session with a stimulus that signaled extinction. For each part, once response rates had stabilized, resistance to change was measured by prefeeding and extinction. When the schedules were examined in successive conditions (Part 1), resistance to extinction was greater under the VI 120-s schedule of reinforcement than under the VI 30-s schedule, but no consistent differences in resistance to prefeeding were observed between the two VI schedules. When the VI schedules alternated each day (Part 2), resistance to extinction was greater under the VI 120-s schedule. However, no consistent differences in resistance to prefeeding were observed between the VI schedules without extinction in Group A, but resistance to prefeeding was greater under the VI 30-s schedule for rats with the added extinction component in Group B. When the VI schedules alternated within the session as a multiple schedule (Part 3), resistance to extinction and resistance to prefeeding were greater under the VI 30-s schedule. The data suggest that different rates of reinforcement, and their accompanying discriminative stimuli, must be compared within the same session (or at least on alternate days) to produce data consistent with the behavioral momentum model.     

Effects of unsignaled delay of reinforcement on preference and resistance to change

In Phase 1, pigeons were trained on a concurrent chain in which a 3-s unsignaled delay of reinforcement was imposed on responding in a terminal link in some conditions. Preference for that terminal link was always reduced in comparison with conditions in which there was no delay, substantially so for 3 of the 4 pigeons. In Phase 2, pigeons responded in a two-component multiple schedule. The scheduled rates of reinforcement were equal, but a 3-s unsignaled delay was imposed in one component. Resistance of responding to prefeeding and extinction was reduced in the delay component for the same 3 subjects for which the data had shown strong effects of delay on preference. Systematic observation revealed differences in response topography. In the delay component, subjects oriented more closely to the key and responses were less forceful compared with the no-delay component. Our results give further evidence that preference and resistance to change covary within subjects. However, they challenge the premise that the critical determiners of preference (i.e., terminal-link value) and resistance to change (behavioral mass) may be quantified purely in terms of stimulus—reinforcer relations.     

A modern psychoanalytic approach to caregiver support groups

Caregiver support groups traditionally focus on education, reduction of social isolation, and supportive sharing. However, the support group literature has increasingly reflected an interest in the emotional effects of caregiving. While some authors promote the therapeutic value of supporting defenses against painful feelings, others have documented the value of encouraging their expression in groups. This paper is based on the author’s experience in co-leading an Alzheimer’s family support group, using a modern psychoanalytic approach which encourages the full expression of the caregivers’ emotional experience. Using emotional communication to explore resistances to intimacy and aggression in groups, the author demonstrates how the interplay of co-leadership and Modern Psychoanalytic theory and techniques promotes group cohesion and encourages maturational growth in group members. This model is also prescribed as an antidote to leader “burnout,” a not uncommon phenomenon for leaders of such emotionally charged groups. Private Practice, New York, New York.     

Effects of response preference on resistance to change

Treatments based on differential reinforcement of alternative behavior, such as functional communication training, are widely used. Research regarding the maintenance of related treatment effects is limited. Nevin and Wacker (2013) provided a conceptual framework, rooted in behavioral momentum theory, for the study of treatment maintenance that addressed two components: (a) reemergence of problem behavior, and (b) continued expression of appropriate behavior. In the few studies on this topic, focus has been on variables impacting the reemergence of problem behavior, with fewer studies evaluating the persistence of appropriate behavior. Given the findings from applied research related to functional communication training, variables related to response topography, such as response preference, may impact this aspect of maintenance. In the current study, the impact of response preference on persistence was evaluated in the context of functional communication training for individuals who did not exhibit problem behavior (Experiment 1) and for individuals with a history of reinforcement for problem behavior (Experiment 2). High‐preferred mands were more persistent than low‐preferred mands. These findings suggest that response related variables, such as response preference, impact response persistence and further suggest that response related variables should be considered when developing interventions such as functional communication training.     

Baseline response rates affect resistance to change

The effect of response rates on resistance to change, measured as resistance to extinction, was examined in two experiments. In Experiment 1, responding in transition from a variable‐ratio schedule and its yoked‐interval counterpart to extinction was compared with pigeons. Following training on a multiple variable‐ratio yoked‐interval schedule of reinforcement, in which response rates were higher in the former component, reinforcement was removed from both components during a single extended extinction session. Resistance to extinction in the yoked‐interval component was always either greater or equal to that in the variable‐ratio component. In Experiment 2, resistance to extinction was compared for two groups of rats that exhibited either high or low response rates when maintained on identical variable‐interval schedules. Resistance to extinction was greater for the lower‐response‐rate group. These results suggest that baseline response rate can contribute to resistance to change. Such effects, however, can only be revealed when baseline response rate and reinforcement rate are disentangled (Experiments 1 and 2) from the more usual circumstance where the two covary. Furthermore, they are more cleanly revealed when the programmed contingencies controlling high and low response rates are identical, as in Experiment 2.     

Digging beneath the surface: Results from stage one of a qualitative analysis of factors influencing the well-being of trans youth in Quebec

ABSTRACT

Background: The literature on trans youth has been dominated by etiological studies interested in trans experience as a medical phenomenon. An emerging body of literature has begun to document that trans youth are a diverse, vulnerable, yet resilient population, and to investigate the role of various sites of support such as the family, peer groups, institutions, and community spaces in contributing to or impeding trans youth's well-being.

Method: This article presents the results of Stage One of interviews (n = 24) conducted for a Community-Based Participatory Action Research (CBPAR) qualitative research project based in Quebec. It studies the factors that enhance trans youth's well-being as well as the factors of oppression that negatively affect it. This paper offers a brief overview of the anti-oppressive methodology used for this project, emphasizing how CBPAR was combined with Grounded Theory (GT) methods to encourage the direct involvement of communities and the translation of knowledge into action.

Results: We present preliminary categories emerging through the ongoing axial coding process. These categories address trans youth's experiences in and perceptions of various “sites”: 1) healthcare services both for gender-related and general care, 2) other institutional spaces, 3) the family and other social circles, and 4) community spaces.

Conclusion: While much of this study's results support existing evidence on trans youth's experiences, they also provide a more nuanced portrayal of the complex ways in which recognition, as well as non-, mis-, or mal-recognition, influence trans youth's well-being at different sites. We also argue that recognition itself must be considered through the lens of intersectionality.     

Where Is Group Treatment Going in the 21st Century?

The author contends that group psychotherapy can be a dynamic force for social change. He shows how group psychotherapists have developed tools that reach far beyond the limits of that particular profession; they deal with the basic interaction among all peoples everywhere in all societies. These tools can be demonstrated, taught, and experienced. In as much as they can be learned, group therapists have to start teaching them to people at the earliest levels of cognitive development. That means that it has to start in our school systems as part of the educational process. A particular kind of specialist has to be trained who can function within the system itself and yet think psychodynamically. The author maintains that this can be accomplished.     

The Clinical Challenges of Assimilative Integration

S. B. Messer (1992) introduced the notion of assimilative integration in psychotherapy, theorizing that integrative practitioners adhere to their preferred theoretical paradigms while judiciously blending aspects from other models. His assimilative approach offers a conceptual and clinical middle ground between technical eclecticism and a grand, unified theory of psychotherapy. However, the practice of competent assimilative integration is fraught with many challenges, both theoretical and clinical. The goal of the present paper is to explore the challenges of implementing assimilative integration. First, the theoretical and clinical barriers to assimilative approaches are considered. Second, the use of assimilative integration to avoid therapeutic failures is discussed. Finally, a case example is presented to illustrate the author's attempt to assimilate narrative, interpretive interventions within his preferred cognitive–behavioral treatment paradigm.