What can vigilance tell us about fear?

Animal vigilance is concerned with the monitoring of potential threats caused by predators and conspecifics. Researchers have argued that threats are part of a landscape of fear tracking the level of risk posed by predators and conspecifics. Vigilance, which is expected to vary with the level of risk, could thus be used as a measure of fear. Here, I explore the relationship between vigilance and fear caused by predators and conspecifics. The joint occurrence of vigilance and other physiological responses to fear, such as increased heart rate and stress hormone release, would bolster the idea that vigilance can be a useful marker of fear. While there is some support for a positive relationship between vigilance and physiological correlates of fear, a common theme in much of the empirical research is that vigilance and physiological correlates of fear are often uncoupled. Uncoupling can arise for several reasons. In particular, vigilance is not always a sensitive or specific marker of the internal state of vigilance. Vigilance might occur in animals who do not appear overtly vigilant or conversely an animal might appear vigilant without necessarily maintaining a state of vigilance. Animals in a fearful state might also be unable to allocate time to vigilance if they are too hungry. Vigilant animals might not show physiological responses associated with fear if they become desensitized to threats. For all these reasons, inferring fear from vigilance is fraught with ambiguity

Coordination and Synchronisation of Anti-Predation Vigilance in Two Crane Species

Much of the previous research on anti-predation vigilance in groups has assumed independent scanning for threats among group members. Alternative patterns that are based on monitoring the vigilance levels of companions can also be adaptive. Coordination of vigilance, in which foragers avoid scanning at the same time as others, should decrease the odds that no group member is alert. Synchronisation of vigilance implies that individuals are more likely to be vigilant when companions are already vigilant. While synchronisation will increase the odds that no one is vigilant, it may allow a better assessment of potential threats. We investigated temporal sequences of vigilance in family flocks consisting of two parents and at most two juveniles in two species of cranes in coastal China. We established whether the observed probability that at least one parent is alert was greater (coordination) or lower (synchronisation) than that predicted under the null hypothesis of independent vigilance. We documented coordination of vigilance in common cranes (Grus grus) foraging in an area with high potential for disturbance by people. We documented synchronisation of vigilance in red-crowned cranes (Grus japonensis) in the less but not in the more disturbed area. Coordination in small flocks leads to high collective vigilance but low foraging rates that may not be suitable in areas with low disturbance. We also argue that synchronisation should break down in areas with high disturbance because periods with low vigilance are riskier. Results highlight the view that temporal patterns of vigilance can take many forms depending on ecological factors

Comparison of peak flow velocity through the left ventricular outflow tract and effective orifice area indexed to body surface area in Golden Retriever puppies to predict development of subaortic stenosis in adult dogs.

Objective — To evaluate the usefulness of Doppler-derived peak flow velocity through the left ventricular outflow tract (LVOT Vmax) and effective orifice area indexed to body surface area (EOAi) in puppies to predict development of subaortic stenosis (SAS) in the same dogs as adults. Design — Prospective, longitudinal, observational study. Animals — 38 Golden Retrievers. Procedures — Cardiac auscultation and echocardiography were performed on 2- to 6-monthold puppies, then repeated at 12 to 18 months. Subaortic stenosis was diagnosed when LVOT Vmax was = 2.3 m/s in adult dogs with left basilar systolic murmurs. Results—All puppies with EOAi < 1.46 cm2/m2 had SAS as adults. All adults with EOAi <1.29 cm2/m2 had SAS. An LVOT Vmax > 2.3 m/s in puppyhood was 63% sensitive and 100% specific for SAS in adulthood. In puppies, LVOT Vmax was more strongly associated with a future diagnosis of SAS (area under the curve [AUC], 0.89) than was EOAi (AUC, 0.80). In puppies, the combination of LVOT Vmax and EOAi yielded slightly higher sensitivity (69%) and specificity (100%) for adult SAS than did LVOT Vmax alone. In unaffected and affected dogs, LVOT Vmax increased significantly from puppyhood to adulthood but EOAi did not. Conclusions and Clinical Relevance — In Golden Retriever puppies, LVOT Vmax > 2.3 m/s and EOAi < 1.46 cm2/m2 were both associated with a diagnosis of SAS at adulthood. The combination of these 2 criteria may result in higher sensitivity for SAS screening. Unlike LVOT Vmax, EOAi did not change during growth in either unaffected Golden Retrievers or those with SAS. (J Am Vet Med Assoc 2014;245:1367–1374

Réussite scolaire, symptômes anxieux et dépressifs rapport de recherche /

"La présente recherche a été subventionnée par le Ministère de l'éducation, du loisir et du sport dans le cadre du Programme d'aide à la recherche sur l'enseignement et l'apprentissage (PAREA)"Titre de l'écran-titre (visionné le 19 février 2008).Également disponible en format papier.Bibliogr

Predator eavesdropping in a mixed-species environment : how prey species may use grouping, confusion, and the cocktail party effect to reduce predator detection

EG is grateful for the support of the Special Talents Recruitment Program of Guangxi University, and National Science Foundation of China grants 31560119 and 31770424.The field of predator eavesdropping concentrates on the detection by a predator or parasite of signals that prey direct at conspecifics, and the subsequent evolution by prey to avoid or lessen such detection. Here, we first point out that signaling prey species are often found in mixed-species moving groups or stationary aggregations, and ask the question of how simultaneous signaling, by members of one species or more, might affect predator eavesdropping behavior and the composition of the groups themselves. The detection risk of prey species will be affected by the other species they associate with, and prey should generally avoid joining a group with more detectable species. Yet prey may select to join other species that are preferred by predators, diluting their own risk of attack, as long as that does not lead to substantially greater detection and thereby increased predation. We next review the evidence that prey grouping and collective responses when attacked can confuse predators, leading to lower capture rates. Evidence for this confusion effect mostly involves visually orienting predators. We then ask if a similar phenomenon could occur when animals in a group simultaneously send acoustic signals, and find relevant evidence for predator confusion under such situations in the literature associated with the "cocktail party effect". As confusion is heightened by similarities among mixed-species group members, this provides a force at ecological or evolutionary timescales to make species that associate in groups, and their signals, more similar to each other. However, heterogeneous mixed-species groups may be favored if species are differentially preferred as prey. We suggest experiments to examine whether the success rates of acoustically orienting predators depend on the group size of their mixed-species prey. More observations on the relative positions of conspecifics and heterospecifics in space, and the temporal association of their signals, will also increase our understanding of the relationship between mixed-species grouping and predator eavesdropping.Publisher PDFPeer reviewe

Redução de fatores de risco em jovens suicidas através de oportunidades de estabelecimento de laços sociais em serviços comunitários

Aim: This study examined the trajectory (life course) of youths, referred to community services following their suicidal behavior, in order to measure the extent to which these young people have taken this opportunity to modify connectedness with family, school, and workplace, and to change high-risk factors related to suicidal behaviors (mental health problems, delinquency, drug consumption). Method: Fifteen youths (aged 16-19), who made one or more suicide attempts or had serious ideation in the previous 24 to 48 months, were referred to community services (Vallée-Jeunesse). They were interviewed using an intensive personal interview measures (Trajectory Instrument Measure, TIM) in order to document significant life events and adversities that occured during different periods of their life.In addition, we administered the Structured Clinical Interview for DSM-IV Axis-I and Axis-II disorders (SCID-I and SCID-II) to identify past and current psychopathologies. Results: Several important changes took place following their entry into the community services: a reduction in delinquency and substance abuse/dependence, and positive changes in occupational status and suicidal behaviors (ideation and suicide attempt). Conclusion: Our findings can inform policies and strategies that support the prevention of suicidal behavior among young adults. Community services providers can play a role in the prevention of suicidal behaviors for the most vulnerable youths. These types of services could complement traditional suicide prevention strategies, which are mostly mental-health based.Objetivo: Este estudo analisou a trajetória (curso de vida) de jovens encaminhados para serviços comunitários após comportamento suicida, a fim de verificar em que medida aproveitaram essa oportunidade para modificar a ligação à família, escola e local de trabalho, e mudar fatores de alto risco relacionados com comportamentos suicidas (problemas de saúde mental, delinquência, consumo de drogas). Método: Quinze jovens (16-19 anos) que fizeram uma ou mais tentativas de suicídio ou manifestaram ideação suicida nos últimos 24 a 48 meses foram referenciados para serviços comunitários (Vallée-Jeunesse). Estes foram entrevistados através de entrevistas pessoais intensivas (Trajectory Instrument Measure, TIM), a fim de registar eventos significativos e adversidades que ocorreram durante diferentes períodos de sua vida. Adicionalmente, foi utilizada a Entrevista Clínica Estruturada para perturbações do Eixo-I e Eixo-II do DSM-IV (SCID-I e SCID-II) para identificar psicopatologias passadas e atuais. Resultados: Várias mudanças importantes ocorreram após a sua entrada nos serviços comunitários: uma redução na delinquência e abuso/dependência de substâncias, e mudanças positivas na situação ocupacional e comportamentos suicidas (ideação e tentativa de suicídio). Conclusão: Os resultados podem fundamentar políticas e estratégias que apoiem a prevenção do comportamento suicida em jovens adultos. Os prestadores de serviços comunitários podem desempenhar um papel na prevenção de comportamentos suicidas para os jovens mais vulneráveis. Esses tipos de serviços poderão complementar estratégias tradicionais de prevenção do suicídio, que são principalmente baseadas em abordagens da saúde mental

Regulation of Cyclooxygenase-2 Expression by the Translational Silencer TIA-1

The cyclooxygenase-2 (COX-2) enzyme catalyzes the rate-limiting step of prostaglandin formation in inflammatory states, and COX-2 overexpression plays a key role in carcinogenesis. To understand the mechanisms regulating COX-2 expression, we examined its posttranscriptional regulation mediated through the AU-rich element (ARE) within the COX-2 mRNA 3′-untranslated region (3′UTR). RNA binding studies, performed to identify ARE-binding regulatory factors, demonstrated binding of the translational repressor protein TIA-1 to COX-2 mRNA. The significance of TIA-1-mediated regulation of COX-2 expression was observed in TIA-1 null fibroblasts that produced significantly more COX-2 protein than wild-type fibroblasts. However, TIA-1 deficiency did not alter COX-2 transcription or mRNA turnover. Colon cancer cells demonstrated to overexpress COX-2 through increased polysome association with COX-2 mRNA also showed defective TIA-1 binding both in vitro and in vivo. These findings implicate that TIA-1 functions as a translational silencer of COX-2 expression and support the hypothesis that dysregulated RNA-binding of TIA-1 promotes COX-2 expression in neoplasia

Rehaussement des interventions en santé mentale : la démarche d'implantation du programme Je tiens la route! : rapport de recherche /

La présente recherche a été rendue possible grâce au soutien financier du Programme d'aide à la recherche sur l'enseignement et l'apprentissage (PAREA) du ministère de l'Éducation, du Loisir et du Sport, du centre Emerging Minds, du regroupement CREO-TÉO-CAPS-Outaouais, de la Fondation du Cégep de l'Outaouais, de la Coopsco - Outaouais et du Cégep de l'Outaouais