A novel copro-diagnostic molecular method for qualitative detection and identification of parasitic nematodes in amphibians and reptiles

© 2017 Huggins et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Anthropogenic disturbance via resource acquisition, habitat fragmentation and climate change, amongst other factors, has led to catastrophic global biodiversity losses and species extinctions at an accelerating rate. Amphibians are currently one of the worst affected classes with at least a third of species categorised as being threatened with extinction. At the same time, they are also critically important for many habitats and provide man with a powerful proxy for ecosystem health by acting as a bioindicator group. Whilst the causes of synchronised amphibian losses are varied recent research has begun to highlight a growing role that macroparasites are playing in amphibian declines. However, diagnosing parasite infection in the field can be problematic, principally relying on collection and euthanasia of hosts, followed by necropsy and morphological identification of parasites in situ. The current study developed a non-invasive PCR-based methodology for sensitive detection and identification of parasitic nematode DNA released in the faeces of infected amphibians as egg or tissue fragments (environmental DNA). A DNA extraction protocol optimised for liberation of DNA from resilient parasite eggs was developed alongside the design of a novel, nematode universal, degenerate primer pair, thus avoiding the difficulties of using species specific primers in situations where common parasite species are unknown. Used in conjunction this protocol and primer pair was tested on a wide range of faecal samples from captive and wild amphibians. The primers and protocol were validated and detected infections, including a Railletnema nematode infection in poison dart frogs from ZSL London Zoo and Mantella cowani frogs in the wild. Furthermore, we demonstrate the efficacy of our PCR-based protocol for detecting nematode infection in other hosts, such as the presence of pinworm (Aspiculuris) in two tortoise species and whipworm (Trichuris muris) in mice. Our environmental DNA approach mitigates problems associated with microscopic identification and can be applied to detect nematode parasitoses in wild and captive hosts for infection surveillance and maintenance of healthy populations

Social coping by masking? Parental support and peer victimization as mediators of the relationship between depressive symptoms and expressive suppression in adolescents

Contains fulltext : 102892pub.pdf (publisher's version ) (Open Access)Expressive suppression is regarded as a generally ineffective emotion regulation strategy and appears to be associated with the development of depressive symptoms among adolescents. However, the mechanisms linking suppression to depressive symptoms are not well understood. The main aim of this study was to examine two potential mediators of the prospective relationship from depressive symptoms to expressive suppression among adolescents: parental support and peer victimization. Structural equation modelling was used to construct a three-wave cross-lagged model (n = 2,051 adolescents, 48.5 % female, at baseline; 1,465 with data at all three time points) with all possible longitudinal linkages. Depressive symptoms preceded decreases in perceived parental support 1 year later. Decreases in parental support mediated the relationship between depressive symptoms and increases in expressive suppression over a 2-year period. Multi-group analyses show that the mediation model tested was significant for girls, but not for boys. No evidence for other mediating models was found. Although initial suppression preceded increases in depressive symptoms 1 year later, we did not find any evidence for the reversed link from suppression to depressive symptoms. Clear evidence for a reciprocal relationship between depressive symptoms and parental support was found. However, only limited and inconsistent support was found for a reciprocal relationship between depressive symptoms and peer victimization. Finally, although some evidence for a unidirectional relationship from parental support to increases in suppression was found, no significant prospective relationship was found between peer victimization and suppression. The implications of our clear results for parental support, and mostly lacking results for peer victimization, are discussed

Perceptions of parenting styles and their associations with mental health and life satisfaction among urban Indonesian adolescents

The study aimed at investigating the association between maternal and paternal parenting styles and psychological well-being among Indonesian adolescents. The Parental Authority Questionnaire (PAQ), General Health Questionnaire-12 (GHQ-12), and the Brief Multidimensional Students’ Life Satisfaction Scale, were administered to 500 adolescents. We were unable to replicate the three-factor solution of the PAQ using confirmatory factor analysis. The permissive subscale demonstrated poor psychometric properties; it was therefore not included in any further analysis. Mothers were perceived to be more authoritative than fathers; on the other hand, fathers were perceived to be more authoritarian than mothers. Both maternal and paternal authoritative parenting styles were positively associated with outcomes. Authoritarian parenting was not associated with any outcome. Scores computed to represent perceived differences between maternal and paternal use of various parenting styles were associated with reported GHQ-12 and life satisfaction scores. Our results confirm Western findings on the positive effects of authoritative parenting, but do not replicate the negative associations of authoritarian parenting. Future studies that examine different parenting styles at the construct level are needed to elucidate the association between parenting styles and adolescent psychological functioning in the Indonesian and other similar contexts