How effective are acoustic signals in territorial defence in the Lusitanian toadfish?

The function of fish sounds in territorial defence, in particular its influence on the intruder's behaviour during territorial invasions, is poorly known. Breeding Lusitanian toadfish males (Halobatrachus didactylus) use sounds (boatwhistles) to defend nests from intruders. Results from a previous study suggest that boatwhistles function as a 'keep-out signal' during territorial defence. To test this hypothesis we performed territorial intrusion experiments with muted Lusitanian toadfish. Males were muted by making a cut and deflating the swimbladder (the sound-producing apparatus) under anaesthesia. Toadfish nest-holder males reacted to intruders mainly by emitting sounds (sham-operated and control groups) and less frequently with escalated bouts of fighting. When the nest-holder produced a boatwhistle, the intruder fled more frequently than expected by chance alone. Muted males experienced a higher number of intrusions than the other groups, probably because of their inability to vocalise. Together, our results show that fish acoustic signals are effective deterrents in nest/territorial intrusions, similar to bird song.

Unemployment as a source of mental distress to individuals and their family: Unemployed parents perceptions during the economic recession

Background: Due to the economic recession, several people in Europe became unemployed. This situation may risk their mental health. Aim: This study explored parents’ perceptions about their unemployment’s effects in daily life during the recession. Methods: A total of 59 unemployed parents (40.7% fathers and 59.3% mothers), ageing 44.4 years (±6.2), answer a question on how the unemployment affected their family lives. Thematic analysis was used to analyse data. Results: The findings suggest that unemployment is a source of adult and youth mental distress and of economic hardship and changes in family relations. Conclusion: Support to unemployed individuals and their families could benefit from these insights when granting the needed financial and socioemotional assistance.

A Quantitative analysis of pulsed signals emitted by wild bottlenose dolphins

Common bottlenose dolphins (Tursiops truncatus), produce a wide variety of vocal emissions for communication and echolocation, of which the pulsed repertoire has been the most difficult to categorize. Packets of high repetition, broadband pulses are still largely reported under a general designation of burst-pulses, and traditional attempts to classify these emissions rely mainly in their aural characteristics and in graphical aspects of spectrograms. Here, we present a quantitative analysis of pulsed signals emitted by wild bottlenose dolphins, in the Sado estuary, Portugal (2011-2014), and test the reliability of a traditional classification approach. Acoustic parameters (minimum frequency, maximum frequency, peak frequency, duration, repetition rate and inter-click-interval) were extracted from 930 pulsed signals, previously categorized using a traditional approach. Discriminant function analysis revealed a high reliability of the traditional classification approach (93.5% of pulsed signals were consistently assigned to their aurally based categories). According to the discriminant function analysis (Wilk's Λ = 0.11, F3, 2.41 = 282.75, P < 0.001), repetition rate is the feature that best enables the discrimination of different pulsed signals (structure coefficient = 0.98). Classification using hierarchical cluster analysis led to a similar categorization pattern: two main signal types with distinct magnitudes of repetition rate were clustered into five groups. The pulsed signals, here described, present significant differences in their time-frequency features, especially repetition rate (P < 0.001), inter-click-interval (P < 0.001) and duration (P < 0.001). We document the occurrence of a distinct signal type-short burst-pulses, and highlight the existence of a diverse repertoire of pulsed vocalizations emitted in graded sequences. The use of quantitative analysis of pulsed signals is essential to improve classifications and to better assess the contexts of emission, geographic variation and the functional significance of pulsed signals.

Distress and unemployment: The related economic and noneconomic factors in a sample of unemployed adults

Objectives To examine the associations between economic and noneconomic factors and psychological distressin a group of 748 unemployed adults during economic recession. Methods Data were collected through a questionnaire. Bivariate and logistic regression analyses were used to test the associations between distress and the deprivation of income and latent benefits of employment (time structure, activity, status, collective purpose and social contact). Results The participants’ mean of distress was higher than the national population mean, and 46.5% of the participants scored above that. All economic and noneconomic factors emerged as strong predictors of distress; particularly financial deprivation (OR 1.06; CI 95 % 1.04–1.09) and lack of structured time (OR 1.07; CI 95 % 1.05–1.09). Women (OR 1.40; CI 95 % 1.04–1.86) and people with lower education levels (OR 0.45; CI 95 % 0.34–0.61) were more affected. Conclusions The unemployed individuals score high on distress, especially those facing financial strain and lack of structured time, and women and individuals with lower education in particular. Given the recessionary context and high unemployment rates, these insights raise awareness for policies and actions targeting the needs of unemployed people.

Unemployment, parental distress and youth emotional well-being: The moderation roles of parent-youth relationship and financial deprivation

We investigated, in a sample of 112 unemployed parents of adolescents aged 10-19 years, the links between parental distress and change in youth emotional problems related to parental unemployment, and the moderation roles of parent-youth relationship and financial deprivation. Data were analyzed using descriptive statistics and correlations. Further, simple moderation, additive moderation, and moderated moderation models of regression were performed to analyze the effects of parental distress, parent-youth relationship and financial deprivation in predicting change in youth emotional problems related to parental unemployment. Results show that parental distress moderated by parent-youth relationship predicted levels of change in youth emotional problems related to parental unemployment. This study provides evidence that during job loss, parental distress is linked to youth emotional well-being and that parent-youth relationships play an important moderation role. This raises the importance of further researching parental distress impacts on youth well-being, especially during periods of high unemployment rates.