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The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Dale F Denardo – 1st expert on this subject based on the ideXlab platform
postural shifts during egg Brooding and their impact on egg water balance in children s pythons antaresia childreniEthology, 2008Co-Authors: Zachary R Stahlschmidt, Ty C M Hoffman, Dale F DenardoAbstract:
Parental care typically consists of distinct behavioral components that are balanced to address the multiple needs of offspring. Female pythons exhibit post-oviposition parental care in which they coil around their parchment-shelled eggs throughout incubation (40‐80 d). Subtle postural shifts during egg-Brooding facilitate embryonic gas exchange but may entail hydric costs to the clutch. This study used a simple behavioral model to (1) further quantify the costs and benefits of specific parental behaviors to developing offspring and (2) determine the influence that developmental stage and relative clutch mass have on parental behavior. Although previous research has demonstrated that egg-Brooding as a whole reduces clutch water loss, we hypothesized that eggBrooding female pythons specifically adopt a tightly coiled posture to conserve embryonic water, but must make postural adjustments to enhance gas exchange between the clutch and nest environments at the cost of increased clutch water loss. We measured rates of water loss in Brooding Children’s pythons (Antaresia childreni) and their respective clutches (i.e., Brooding units) and monitored changes in Brooding posture. We conducted serial trials to elucidate the effect of developmental stage on postural adjustments and water loss. Results demonstrated that the proportion of time females spent in a tightly coiled posture was inversely related to mean water loss from the Brooding unit. Analyses indicated that slight adjustments in posture led to bursts in Brooding unit water loss. Indeed, Brooding unit water loss during postural adjustments was significantly higher than during tight coiling. These findings imply that python egg-Brooding provides an adjustable diffusive barrier that leads to discontinuous gas exchange, which minimizes clutch water loss. Because females with larger relative clutch masses spent more time tightly coiled, egg-Brooding female pythons may use a ‘water first’ strategy in which they intentionally conserve clutch water at the cost of reduced embryonic respiratory gas exchange.
alternating egg Brooding behaviors create and modulate a hypoxic developmental micro environment in children s pythons antaresia childreniThe Journal of Experimental Biology, 2008Co-Authors: Zachary R Stahlschmidt, Dale F DenardoAbstract:
SUMMARY Parental care is a widespread and ecologically relevant adaptation known to
enhance the developmental environment of offspring. Parental behaviors,
however, may entail both costs and benefits for developing offspring. In
Children9s pythons ( Antaresia childreni ), we monitored both maternal
egg-Brooding behavior and intra-clutch oxygen partial pressure
( P O 2 ) in real-time to assess the effects of
various Brooding behaviors on P O 2 in the clutch
micro-environment at three stages of development. Furthermore, at the same
developmental stages, we measured O 2 consumption rates
( V O 2 ) of eggs at
varying P O 2 to determine their critical oxygen
tension (i.e. the minimal P O 2 that supports
normal respiratory gas exchange) and to predict the impact that naturally
brooded intra-clutch P O 2 has on embryonic
metabolism. At all three stages of development, a tightly coiled Brooding
posture created an intra-clutch P O 2 that was
significantly lower than the surrounding nest environment. Maternal postural
adjustments alleviated this hypoxia, and the magnitude of such corrections
increased with developmental stage. Mean intra-clutch
P O 2 decreased with stage of development,
probably because of increasing egg
V O 2 .
Additionally, embryo critical oxygen tension increased with developmental
stage. Together, these results suggest that python embryos are unable to
maintain normal metabolism under brooded conditions during the final 10% of
incubation. These results demonstrate that specific parental behaviors can
impose obligatory costs to developing offspring and that balancing these
behaviors can mediate deleterious consequences.
maternal Brooding in the children s python antaresia childreni promotes egg water balanceJournal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2007Co-Authors: Olivier Lourdais, Ty C M Hoffman, Dale F DenardoAbstract:
Parental care provides considerable benefits to offspring and is widespread among animals, yet it is relatively uncommon among squamate reptiles (e.g., lizards and snakes). However, all pythonine snakes show extended maternal egg Brooding with some species being facultatively endothermic. While facultative endothermy provides thermal benefits, the presence of Brooding in non-endothermic species suggests other potential benefits of Brooding. In this study we experimentally tested the functional significance of maternal Brooding relative to water balance in the children’s python, Antaresia childreni, a small species that does not exhibit facultative endothermy. Clutch evaporative water loss (EWL) was positively correlated with clutch mass and was much lower than expected values based on individual eggs. The conglomerate clutch behaved as a single unit with a decreasing surface area to volume ratio as clutch size increased. Maternal Brooding had a dramatic impact on evaporation from eggs, reducing and possibly eliminating clutch EWL. In a separate experiment, we found that viability of unattended eggs is highly affected by humidity level, even in the narrow range from 75 to 100% relative humidity at 30.5°C (20–33 mg m−3 absolute humidity). However, the presence of the Brooding female ameliorated this sensitivity, as viability of brooded clutches at 75% relative humidity was higher than that of non-brooded eggs at either the same absolute humidity or at near-saturated conditions. Overall, these results demonstrate that Brooding behavior strongly promotes egg water balance (and thus egg viability) in children’s pythons.
Regina Miranda – 2nd expert on this subject based on the ideXlab platform
cognitive inflexibility and suicidal ideation mediating role of Brooding and hopelessnessPsychiatry Research-neuroimaging, 2013Co-Authors: Regina Miranda, Jorge Valderrama, Aliona Tsypes, Erin Gadol, Michelle GallagherAbstract:
Previous research suggests that cognitive inflexibility prospectively increases vulnerability to suicidal ideation, but the specific cognitive factors that may explain the relation have not been examined empirically. The present study examined the Brooding subtype of rumination and hopelessness as potential mediators of the prospective relation between cognitive inflexibility and suicidal ideation. Fifty-six young adults who completed a measure of cognitive inflexibility and suicidal ideation at baseline were followed up 2–3 years later and completed measures of Brooding, hopelessness, and suicidal ideation. Cognitive inflexibility at baseline predicted suicidal ideation at follow up, adjusting for baseline ideation. This relation was mediated by Brooding but not by hopelessness. However, there was an indirect relation between perseverative errors and suicidal ideation through Brooding, followed by hopelessness, such that Brooding was associated with greater hopelessness and hopelessness, in turn, was associated with greater suicidal ideation. Cognitive inflexibility may increase vulnerability to suicidal thinking because it is associated with greater Brooding rumination, while Brooding, in turn, is associated with hopelessness.
Brooding and reflective rumination among suicide attempters cognitive vulnerability to suicidal ideationBehaviour Research and Therapy, 2009Co-Authors: Katherine Surrence, Regina Miranda, Brett Marroquin, Shirley ChanAbstract:
Previous research suggests that the Brooding subtype of rumination is associated with increased suicidal ideation, but findings are inconsistent with respect to reflection, considered to be the more adaptive form of rumination. This study investigated the circumstances under which reflective rumination might be associated with increased suicidal ideation by examining whether a suicide attempt history moderated the relationship between the ruminative subtypes and current suicidal ideation. Thirty-seven young adults who reported a past suicide attempt and fifty-nine young adults without a suicide attempt history completed measures of rumination and depression symptoms in an initial study session. They then completed a measure of suicidal ideation and hopelessness during a second study session. Overall, Brooding was associated with higher self-reported suicidal ideation, whereas reflection was not significantly associated with ideation. However, reflection – but not Brooding – interacted with suicide attempt history to statistically predict suicidal ideation, even after adjusting for symptoms of depression and hopelessness, whereas Brooding no longer predicted ideation after adjusting for these symptoms. These findings qualify earlier suggestions that reflection is a more adaptive form of rumination by indicating that among vulnerable individuals – in particular those with a history of a suicide attempt – a higher degree of reflective rumination is associated with increased suicidal ideation.
Brooding and reflection rumination predicts suicidal ideation at 1 year follow up in a community sampleBehaviour Research and Therapy, 2007Co-Authors: Regina Miranda, Susan NolenhoeksemaAbstract:
The cognitive processes underlying suicidal thinking and behavior are not well understood. The present study examined Brooding and reflection, two dimensions of rumination, as predictors of suicidal ideation among a community sample of 1134 adults. Participants completed self-report measures of rumination and depression, and a semi-structured clinical interview that included an assessment of suicidal ideation, at baseline and 1-year follow-up. Brooding was more strongly related to degree of ideation at baseline than was reflection. However, both Brooding and reflection predicted whether an individual thought about suicide at 1-year follow-up, even after adjusting for baseline suicidal ideation. Symptoms of depression mediated the relationship between Brooding and ideation but not that between reflection and ideation. Implications for the nature of thought processes that result in suicidal thinking are discussed.
Filip Raes – 3rd expert on this subject based on the ideXlab platform
moderating effects of Brooding and co rumination on the relationship between stress and depressive symptoms in early adolescence a multi wave studyJournal of Abnormal Child Psychology, 2015Co-Authors: Margot Bastin, Filip Raes, Amy H. Mezulis, Josh Ahles, Patricia BijttebierAbstract:
The current study investigated Brooding and co-rumination as moderators of the relationship between interpersonal and noninterpersonal stress and depressive symptom trajectories. The sample consisted of 368 early adolescents ages 9 to 15 (M = 11.72, 63 % female) who completed self-report measures of Brooding, co-rumination, stress, and depressive symptoms at baseline with follow-up assessments of stress and depressive symptoms at 3, 8, and 12 months post-baseline. Data were analyzed using multi-level modeling. Results showed that the association between interpersonal stress and depressive symptoms was stronger for adolescents high on Brooding, compared to adolescents low on Brooding. Sex moderated a co-rumination × stress interaction, with girls high on co-rumination and boys low on co-rumination reporting the highest levels of depressive symptoms when faced with interpersonal stress across the 1-year study period. These findings shed light on pathways to depressive symptoms in early adolescence and suggest that adolescent boys and girls may differ in these pathways.
Brooding and reflecting in an interpersonal contextPersonality and Individual Differences, 2014Co-Authors: Margot Bastin, Patricia Bijttebier, Filip Raes, Michael W. VaseyAbstract:
Abstract Rumination consists of two components: Brooding, which increases depressive feelings, and reflection, which appears to be unrelated to or protective against depression. The present study is the first to extend the intrapersonal constructs of Brooding and reflection to the interpersonal context, thereby relying on previous work in the domain of co-rumination. In this two-wave longitudinal study, a community sample of 371 pupils (63.1% girls) aged 9–15 years was followed up over a three-month interval. Using items drawn from the Co-Rumination Questionnaire (Rose, 2002), a two-factor model distinguishing between co-Brooding and co-reflection was validated using confirmatory factor analysis. Both co-Brooding and co-reflection emerged as significant unique predictors of depressive symptoms over a three-month interval, above and beyond sex and baseline depressive symptoms. Co-Brooding had a positive association with prospective depressive symptoms, whereas co-reflection was inversely related to prospective symptom levels. This pattern of results was unchanged when controlling for intrapersonal Brooding and reflection. Post-hoc analyses revealed that co-Brooding and co-reflection could be framed as higher order factors, each encompassing two lower-order factors and that the effects are carried by specific aspects of co-Brooding and co-reflection, i.e., co-Brooding on consequences and co-reflecting on causes of problems.
Brooding and reflection as subtypes of rumination evidence from confirmatory factor analysis in nonclinical samples using the dutch ruminative response scaleJournal of Psychopathology and Behavioral Assessment, 2010Co-Authors: Hanne Schoofs, Dirk Hermans, Filip RaesAbstract:
Previous research has shown that depressive rumination is an important vulnerability factor for experiencing depressive symptoms. The most widely used measure to assess depressive rumination is the Ruminative Response Scale (RRS). According to Treynor et al. (Cognitive Therapy and Research 27:247–259, 2003), the RRS contains two subscales, reflecting two different rumination subcomponents: Brooding and reflection. The present study examined the psychometric properties of the RRS in two samples (N = 432 and N = 407). Based on a confirmatory factor analysis (CFA), results confirmed that a two-dimensional model with Brooding and reflection factors provided an adequate fit to the data. Reliability, convergent and discriminant validity of the rumination subcomponents were appropriate. Furthermore, Brooding but not reflection predicted depressive symptoms prospectively, even when accounting for concurrent depressive feelings. The results provide the first confirmatory factor-analytical support for the widely assumed two-factor model of the RRS and add to the accumulating body of evidence supporting the multidimensional nature of depressive rumination.