Positive Relationship between Signalling Time and Flight Capability in the Texas Field Cricket, Gryllus texensis

1. Should females increase or decrease reproduction when attacked by pathogens? Two hypotheses provide opposite predictions. Terminal reproductive investment theory predicts an increase in reproduction, but hypothesized physiological trade-offs between reproduction and immune function might be expected to produce a decrease. There is evidence for both hypotheses. What determines the choice between the two responses remains unclear. We examine the effect of age on the reproductive response to immune challenge in long-wing females of the Texas field cricket, Gryllus texensis, when fed an ecologically valid (limited) diet. 2. The limited diet reduced reproductive output. However, immune challenge had no effect on their reproductive output either in young or middle-aged crickets, which is contrary to either prediction. 3. Flight muscle maintenance correlated negatively with reproductive output, suggesting a physiological trade-off between flight muscle maintenance and reproduction. Within the long-wing variant there was considerable variability in flight muscle maintenance. This variability may mask physiological trade-offs between immunity and reproduction. 4. Middle-aged crickets had higher total phenoloxidase (PO) activity in their hemolymph, compared to young females, which is contrary to the terminal investment theory. Given that PO is involved in both immunity and reproduction, the increased PO may reflect simultaneous investment in both functions. 5. We identified four proPO transcripts in a published RNA-seq dataset (transcriptome). Three of the proPO genes were expressed either in the fat body or the ovaries (supporting the hypothesis that PO is bifunctional); however, the two organs expressed different subsets. The possible bifunctionality of PO suggests that it may not be an appropriate immune measure for immune/reproductive trade-offs in some species. 6. Increasing age may not cue terminal reproductive investment prior to senescence.

Download Full-text

Epistemic and relational conflicts in sharing identical vs. complementary information during cooperative learning

Swiss Journal of Psychology ◽

10.1024//1421-0185.61.3.139 ◽

2002 ◽

Vol 61 (3) ◽

pp. 139-151 ◽

Cited By ~ 20

Author(s):

Céline Darnon ◽

Céline Buchs ◽

Fabrizio Butera

Keyword(s):

Cooperative Learning ◽

Social Comparison ◽

Positive Relationship ◽

Learning Task ◽

Control Group ◽

Complementary Information ◽

Relational Conflict ◽

The Social ◽

The University

When interacting on a learning task, which is typical of several academic situations, individuals may experience two different motives: Understanding the problem, or showing their competences. When a conflict (confrontation of divergent propositions) emerges from this interaction, it can be solved either in an epistemic way (focused on the task) or in a relational way (focused on the social comparison of competences). The latter is believed to be detrimental for learning. Moreover, research on cooperative learning shows that when they share identical information, partners are led to compare to each other, and are less encouraged to cooperate than when they share complementary information. An epistemic vs. relational conflict vs. no conflict was provoked in dyads composed by a participant and a confederate, working either on identical or on complementary information (N = 122). Results showed that, if relational and epistemic conflicts both entailed more perceived interactions and divergence than the control group, only relational conflict entailed more perceived comparison activities and a less positive relationship than the control group. Epistemic conflict resulted in a more positive perceived relationship than the control group. As far as performance is concerned, relational conflict led to a worse learning than epistemic conflict, and - after a delay - than the control group. An interaction between the two variables on delayed performance showed that epistemic and relational conflicts were different only when working with complementary information. This study shows the importance of the quality of relationship when sharing information during cooperative learning, a crucial factor to be taken into account when planning educational settings at the university.

Download Full-text

Are Deficits in Social Cognition Linked to Autobiographical Memory in Patients with Alzheimer’s Disease?

Zeitschrift für Neuropsychologie ◽

10.1024/1016-264x/a000187 ◽

2016 ◽

Vol 27 (4) ◽

pp. 257-264 ◽

Cited By ~ 3

Author(s):

Johannes H. Scheidemann ◽

Franz Petermann ◽

Marc Schipper

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Social Cognition ◽

Theory Of Mind ◽

Autobiographical Memory ◽

Positive Relationship ◽

Neuropsychological Test ◽

Clinical Group ◽

Neuropsychological Test Battery ◽

Fluency Task

Abstract. We investigated theory of mind (ToM) deficits in Alzheimer‘s disease (AD) and its possible connection to autobiographical memory (ABM). Patients and matched controls were evaluated and compared using a video-based ToM test, an autobiographical fluency task, and a neuropsychological test battery. We found that ToM deficits were positively associated with semantic ABM in the clinical group, whereas a positive relationship appeared between ToM and episodic ABM in controls. We hypothesize that this reflects the course of the disease as well as that semantic ABM is used for ToM processing, being still accessible in AD. Furthermore, we assume that it is also less efficient, which in turn leads to a specific deficit profile of social cognition.

Download Full-text