Do Individual Differences in Emotion Regulation Mediate the Relationship Between Mental Toughness and Symptoms of Depression?

Mental Toughness (MT) provides crucial psychological capacities for achievement in sports,
education, and work settings. Previous research examined the role of MT in the domain of
mental health and showed that MT is negatively associated with and predictive of fewer
depressive symptoms in non-clinical populations. The present study aimed at 1) investigating
to what extent mentally tough individuals use two emotion regulation strategies: cognitive
reappraisal and expressive suppression; 2) exploring whether individual differences in
emotion regulation strategy use mediate the relationship between MT and depressive
symptoms. Three hundred sixty-four participants (M = 24.31 years, SD = 9.16) provided
self-reports of their levels of MT, depressive symptoms, and their habitual use of cognitive
reappraisal and expressive suppression. The results showed a statistically significant
correlation between MT and two commonly used measures of depressive symptoms. A small
statistically significant positive correlation between MT and the habitual use of cognitive
reappraisal was also observed. The correlation between MT and the habitual use of
expressive suppression was statistically significant, but the size of the effect was small. A
statistical mediation model indicated that individual differences in the habitual use of
expressive suppression mediate the relationship between MT and depressive symptoms. No
such effect was found for the habitual use of cognitive reappraisal. Implications of these
findings and possible avenues for future research are discussed.

Contact as a Policy Mechanisim in Integrated schools in Israel and Northern Ireland

Policy initiatives in inter-group education evolved in Northern Ireland and Israel at around the same
time. In each jurisdiction, the emphasis is on improving relations between protagonist groups in
ethnically divided societies. Central to this objective and at the core of integrated education
(Northern Ireland) and bilingual/bi-national education (Israel) is sustained contact in a shared
learning environment. Based on qualitative research in four schools, this paper examines the nature
of the contact experience in two integrated schools in Northern Ireland and two bilingual/binational
schools in Israel. Through comparative analysis, and with reference to contact theory, it
illuminates some of the contextual and process variables that seemingly mediate the quality and
moderate the effectiveness of contact in each school setting.

Parasite mediated predation between native and invasive amphipods.

Parasites can structure biological communities directly through population regulation and indirectly by processes such as apparent competition. However, the role of parasites in the process of biological invasion is less well understood and mechanisms of parasite mediation of predation among hosts are unclear. Mutual predation between native and invading species is an important factor in determining the outcome of invasions in freshwater amphipod communities. Here, we show that parasites mediate mutual intraguild predation among native and invading species and may thereby facilitate the invasion process. We find that the native amphipod Gammarus duebeni celticus is host to a microsporidian parasite, Pleistophora sp. (new species), with a frequency of infection of 0-90%. However, the parasite does not infect three invading species, G. tigrinus, G. pulex and Crangonyx pseudogracilis. In field and laboratory manipulations, we show that the parasite exhibits cryptic virulence: the parasite does not affect host fitness in single-species populations, but virulence becomes apparent when the native and invading species interact. That is, infection has no direct effect on G. d. celticus survivorship, size or fecundity; however, in mixed-species experiments, parasitized natives show a reduced capacity to prey on the smaller invading species and are more likely to be preyed upon by the largest invading species. Thus, by altering dominance relationships and hierarchies of mutual predation, parasitism strongly influences, and has the potential to change, the outcome of biological invasions.

Effects of trauma on bipolar disorder: the mediational role of interpersonal difficulties and alcohol dependence

Objectives: This study examined: (i) the prevalence of trauma in a bipolar disorder (BD) sample, and (ii) how trauma histories mediated by interpersonal difficulties and alcohol dependence impact on the severity of BD. The prevalence of posttraumatic stress disorder (PTSD) and its relationship to outcomes in BD were also examined.

Methods: Sixty participants were recruited from a geographically well-defined mental health service in Northern Ireland. Self-reported trauma histories, PTSD, interpersonal difficulties and alcohol dependence and were examined in relation to illness severity.

Results: A high prevalence of trauma was found. Trauma predicted the frequency of hospital admissions (R-2 = 0.08), quality of life (R-2 = 0.23) and inter-episode depressive symptoms (R-2 = 0.13). Interpersonal difficulties, but not alcohol dependence, appeared to play an important role in mediating these adverse effects. While only 8% of the sample met criteria for active PTSD, this comorbid disorder was associated with BD severity.

Conclusions: This study indicates that awareness of trauma is important in understanding individual differences in bipolar presentations. The theoretical and clinical implications of evidence that trauma is related to more adverse outcomes in BD are discussed. The finding that interpersonal difficulties mediate the relationship between trauma and BD severity is novel. The need for adjunctive evidence-based treatments targeting interpersonal difficulties is considered.

Entanglers: Beam splitters and thermal fields

Entanglement is an important ingredient for quantum information processing. We discuss some sources of entanglement, namely a beam splitter and a thermal field. For the generation of entangled continuous-variable states, we consider a beam splitter and find some conditions for input fields to see entanglement in the output. While a beam splitter is a unitary device to generate an entangled state for a bipartite continuous-variable system, a thermal field is shown to mediate entanglement of two qubits.

Validity, trustworthiness and rigour:reasserting realism in qualitative research

Aim The aim of this paper is to challenge recent sceptical approaches to the possibility of validating qualitative research and to underline the benefits of adopting a realist approach to validity. Background In recent discussion about the methodological bases for qualitative research it has been argued that, because different methodologies take different approaches to validity, attempts to develop a common set of validation criteria are futile. On the basis of this sceptical view, a number of strategies for judging qualitative research have been proposed. These include suggestions that: it should be judged according to aesthetic or rhetorical criteria, rather than epistemological validity; responsibility for appraisal should move from researchers to readers; each methodology should be assessed individually according to its own merits. Discussion None of these suggestions provide a viable alternative to validity, defined as the extent to which research reflects accurately that to which it refers. Because the form of research does not determine its content, replacement of epistemology by aesthetics is unsustainable. Because research reports mediate between writer and reader, a one-sided approach to this relationship constitutes a false dichotomy. If we accept the criterion of practitioner confidence as a means of judging methodological approaches, this involves rejection of judgement according to a methodology�s own merits. Conclusion If qualitative research is actually about something, and if it is required to provide beneficial information, then a realist approach to validity holds out greatest promise.

How parasites affect interactions between competitors and predators

We present a synthesis of empirical and theoretical work investigating how parasites influence competitive and predatory interactions between other species. We examine the direct and indirect effects of parasitism and discuss examples of density and parasite-induced trait-mediated effects. Recent work reveals previously unrecognized complexity in parasite-mediated interactions. In addition to parasite-modified and apparent competition leading to species exclusion or enabling coexistence, parasites and predators interact in different ways to regulate or destablize the population dynamics of their joint prey. An emerging area is the impact of parasites on intraguild predation (IGP). Parasites can increase vulnerability of infected individuals to cannibalism or predation resulting in reversed species dominance in IGP hierarchies. We discuss the potential significance of parasites for community structure and biodiversity, in particular their role in promoting species exclusion or coexistence and the impact of emerging diseases. Ongoing invasions provide examples where parasites mediate native/invader interactions and play a key role in determining the outcome of invasions. We highlight the need for more quantitative data to assess the impact of parasites on communities, and the combination of theoretical and empirical studies to examine how the effects of parasitism scale up to community-level processes.

Role of calcium influx through voltage-operated calcium channels and of calcium mobilization in the physiology of Schistosoma mansoni muscle contractions

We tested the hypothesis that voltage-operated Ca2+ channels mediate an extracellular Ca2+ influx in muscle fibres from the human parasite Schistosoma mansoni and, along with Ca2+ mobilization from the sarcoplasmic reticulum, contribute to Muscle contraction. Indeed, whole-cell voltage clamp revealed voltage-gated inward currents carried by divalent ions with a peak current elicited by steps to + 20 mV (from a holding potential of -70 mV). Depolarization of the fibres by elevated extracellular K+ elicited contractions that were completely dependent on extracellular Ca2+ and inhibited by nicardipine (half inhibition at 4(.)1 mu M). However these contractions were not very sensitive to other classical blockers of voltage-gated Ca2+ channels, indicating that the schistosome Muscle channels have an atypical pharmacology when compared to their mammalian counterparts. Furthermore, the contraction induced by 5 mM caffeine was inhibited after depletion of the sarcoplasmic reticulum either with thapsigargin (10 mu M) or ryanodine (10 mu M). These data suggest that voltage-operated Ca2+ channels docontribute to S. mansoni contraction as does the mobilization of stored Ca2+, despite the small volume of sarcoplasmic reticulum in schistosome smooth muscles.

Adjustment to inflammatory bowel disease: The relative influence of illness perceptions and coping

Background: The Common Sense Model (CSM) of illness representations was used in the current study to examine the relative contribution of illness perceptions and coping strategies in explaining adjustment to inflammatory bowel disease (IBD). Methods: Participants were 80 adults consecutively attending an outpatients' clinic with a diagnosis of either Crohn's disease or ulcerative colitis. Respondents completed and returned a questionnaire booklet that assessed illness perceptions, coping, and adjustment. Adjustment was measured from the perspectives of psychological distress, quality of life, and functional independence. Results: Illness perceptions (particularly perception of consequences of IBD) were uniformly the most consistent variables explaining adjustment to IBD. Coping did not significantly add to predicting adjustment once illness perceptions were controlled for and therefore did not mediate the relationship between illness perceptions and adjustment, as proposed in the CSM. Conclusions: The results suggest the importance of addressing illness perceptions in developing appropriate psychological interventions for IBD.

Protein kinase B/Akt activity is involved in renal TGF-beta 1-driven epithelial-mesenchymal transition in vitro and in vivo

The molecular pathogenesis of diabetic nephropathy (DN), the leading cause of end-stage renal disease worldwide, is complex and not fully understood. Transforming growth factor-beta (TGF-beta1) plays a critical role in many fibrotic disorders, including DN. In this study, we report protein kinase B (PKB/Akt) activation as a downstream event contributing to the pathophysiology of DN. We investigated the potential of PKB/Akt to mediate the profibrotic bioactions of TGF-beta1 in kidney. Treatment of normal rat kidney epithelial cells (NRK52E) with TGF-beta1 resulted in activation of phosphatidylinositol 3-kinase (PI3K) and PKB/Akt as evidenced by increased Ser473 phosphorylation and GSK-3beta phosphorylation. TGF-beta1 also stimulated increased Smad3 phosphorylation in these cells, a response that was insensitive to inhibition of PI3K or PKB/Akt. NRK52E cells displayed a loss of zona occludins 1 and E-cadherin and a gain in vimentin and alpha-smooth muscle actin expression, consistent with the fibrotic actions of TGF-beta1. These effects were blocked with inhibitors of PI3K and PKB/Akt. Furthermore, overexpression of PTEN, the lipid phosphatase regulator of PKB/Akt activation, inhibited TGF-beta1-induced PKB/Akt activation. Interestingly, in the Goto-Kakizaki rat model of type 2 diabetes, we also detected increased phosphorylation of PKB/Akt and its downstream target, GSK-3beta, in the tubules, relative to that in control Wistar rats. Elevated Smad3 phosphorylation was also detected in kidney extracts from Goto-Kakizaki rats with chronic diabetes. Together, these data suggest that TGF-beta1-mediated PKB/Akt activation may be important in renal fibrosis during diabetic nephropathy.

Reducing the mapping between perception and action facilitates imitation

This study investigated two hypotheses regarding the mapping of perception to action during imitation. The first hypothesis predicted that as children’s cognitive capacities increase the tendency to map one goal and disregard others during imitation should decrease. This hypothesis was tested by comparing the performances of 168 4- to 7-year-olds in a gestural imitation task developed by Bekkering, Wohlschläger, and Gattis. The second hypothesis predicted that reducing the mapping between perception and action should reduce the demands on the cognitive resources of the child. This hypothesis was tested by creating a condition in which perception and action overlapped by sharing objects between experimenter and child. In three experimental conditions, an adult modelled four gestures, directed at either: 1) one of two sets of round stickers (proprietary objects); 2) the same location on the table, without any sticker (no objects); or 3) one set of round stickers, which were shared with the child (shared objects). The results confirmed both hypotheses. Four- and five-year-olds imitated less accurately when imitation involved mapping of both objects and movements (proprietary and shared objects) than when imitation involved mapping movements only (no objects). Seven-year-olds imitated accurately in all three conditions, demonstrating that increased cognitive capacity allowed them to map multiple goals from perception to action. Most importantly, reducing the mapping between perception and action in the shared objects condition facilitated imitation, specifically for the transitional group, 6-year-olds. We conclude that mapping between perception and action is not direct, but resembles mapping relations in analogical reasoning: cognitive processes mediate mapping from perception to action.

Role of behaviour in biological invasions and species distributions; lessons from interactions between the invasive Gammarus pulex and the native G-duebeni (Crustacea : Amphipoda)

In attempting to understand the distributions of both introduced species and the native species on which they impact, there is a growing trend to integrate studies of behaviour with more traditional life history/ecological approaches. The question of what mechanisms drive the displacement of the freshwater amphipod Gammarus duebeni by the often introduced G pulex is presented as a case study Patterns of displacement are well documented throughout Europe, but the speed and direction of displacement between these species can be varied. From early studies proposing interspecific competition as causal in these patterns, I review research progress to date. I show there has been no evidence for interspecific competition operating, other than the field patterns themselves, a somewhat tautological argument. Rather, the increased recognition of behavioural attributes with respect to the cannibalistic and predatory nature of these species gave rise to a series of studies unravelling the processes driving field patterns. Both species engage in 'intraguild predation' (IGP), with moulting females particularly vulnerable to predation by congeneric males. G pulex is more able both to engage in and avoid this interaction with G duebeni. However, several factors mediate the strength and asymmetry of this IGP, some biotic (e.g. parasitism) and others abiotic (e.g. water chemistry). Further, a number of alternative hypotheses that may account for the displacement (hybridization; parasite transmission) have been tested and rejected. While interspecific competition has been modelled mathematically and found to be a weak interaction relative to IGP, mechanisms of competition between these Gammarus species remain largely untested empirically. Since IGP may be finely balanced in some circumstances, I conclude that the challenge to detect interspecific competition remains and we require assessment of its role, if any, in the interaction between these species. Appreciation of behavioural attributes and their mediation should allow us to more fully understand, and perhaps predict, species introductions and resultant distributions.

Potential roles for differential body size and microhabitat complexity in mediating biotic interactions within invasive freshwater amphipod assemblages

Cannibalism and intraguild predation (IGP) are common amongst freshwater amphipod crustacean aswsemblages, particularly between individuals of different body size, with IGP of smaller by larger species. The decline of Gammarus tigrinus Populations in mainland Europe has been accompanied by the arrival of the Ponto-Caspian invader Dikerogammarus villosus and previous studies have implicated IGP of G. tigrinus by the larger D. villosus as the principal driving force in this replacement. We examined how factors such as microhabitat and body size may mediate both cannibalism within G. tigrinus populations and IGP by D. villosus and thus contribute to field patterns of coexistence and exclusion. A field Survey of an invaded Dutch fake indicated that G. tigrinus and D. villosus differed in distribution. with D. villosus being the numerically dominant amphipod (80-96 %) on the rocky boulder Substrate of the shoreline and G. tigrinus being the dominant amphipod (100 %) in the crushed shell/sand matrix immediately adjacent to this. Laboratory microcosm experiments indicated that G. tigrinus cannibalism, particularly of smaller by larger size classes, may be common. In addition, although D. villosus predation of all G. tigrinus size classes was extreme, the smallest size classes Suffered the highest predation. Indeed, when exposed to D. villosus, predation of larger G. tigrinus was lowest when smaller G. tigrinus were also present. Increasing microhabitat complexity from a simple bare substrate littered with Dreissena polymorpha zebra mussels to a Crushed shell/sand matrix significantly reduced both cannibalism and IGP. Our Study emphasizes the need to consider both life history stages and habitat template, when considering the impacts of biotic interactions and it also emphasizes that complex, interacting factors may be mediating the range expansion of D. villosus.

An acanthocephalan parasite mediates intraguild predation between invasive and native freshwater amphipods (Crustacea)

1. The balance of predation between closely related invasive and native species can be an important determinant of the success or failure of biological invasions. In Irish freshwaters, the introduced amphipod Gammarus pulex has replaced the native G. duebeni celticus, possibly through differential mutual intraguild predation (IGP). Theoretically, parasitism could mediate such predation and hence the invasion outcome. However, this idea remains poorly studied.