ABSTRACT Antipredator behaviour reflects both evolutionary history and individual experience, yet how populations respond to changes in predator exposure remains poorly understood, particularly for large invertebrates. We examined antipredator behaviour in two populations of stone wētā (Hemideina maori Pictet & Saussure, 1891) inhabiting weka‐free Mou Tapu and nearby Mou Waho, where weka (Gallirallus australis hectori—a large flightless rail) were translocated in 2004 and persist. Wētā were collected from both islands and assayed under controlled laboratory conditions to quantify refuge use, locomotor activity, exploratory behaviour, and defensive responses to simulated attack. Morphological traits did not differ between islands, aside from a weak trend toward longer hind femora in Mou Waho individuals. Refuge‐seeking behaviour and open‐field activity did not vary between populations, nor did exploratory tendencies. However, predator‐experienced Mou Waho wētā were substantially more defensive: 84% responded aggressively to the first simulated attack compared with 58% of Mou Tapu individuals, and larger wētā showed stronger defensive responses irrespective of origin. Defensive behaviour types (fending, fleeing, rasping) were conserved across populations, suggesting that differing recent exposure to weka altered the threshold at which antipredator behaviours were deployed rather than the underlying behavioural repertoire itself. Field observations revealed striking microhabitat restriction on Mou Waho, where wētā were found only beneath large summit rocks, consistent with sustained predation pressure. Our findings demonstrate that predator experience selectively enhances reactive components of antipredator behaviour without altering proactive behaviours such as refuge‐seeking or activity. These results highlight the importance of behavioural assessments in conservation planning, especially when predator‐naïve populations may face re‐exposure to native predators through restoration or translocation programmes.

AbstractTemperature is a key environmental factor influencing animal behavior, including foraging, predator avoidance, and habitat use. Intertidal fishes already experience extreme thermal variability and may be especially vulnerable to further environmental change; therefore, understanding how their behavior responds to temperature fluctuations is essential. This study investigates how chronic exposure to two ecologically relevant temperatures (10 °C and 20 °C) shapes the behavior of the intertidal common triplefin, Forsterygion lapillum. We use a series of behavioral assays to assess activity, emergence, feeding, evasive responses, and aggression. During the 6-week acclimation period, fish in the 20 °C treatment consumed more food and spent less time hidden within refuges. Fish acclimated to 20 °C also exhibited greater overall activity, increased aggression, and a shorter latency to initiate movement. However, evasive responses to a simulated bird strike did not differ significantly between treatments. These findings demonstrate that warmer conditions can substantially alter the behavior of intertidal triplefins. While elevated activity and aggression may bolster foraging success and territorial defense, they also bring higher energetic demands and increased risk of predator exposure. These trade-offs may ultimately influence individual survival, reproductive success, and population-level outcomes. In the context of ongoing climate change, our findings underscore the need to understand species-specific behavioral responses to warming. Even subtle behavioral shifts could cascade through intertidal communities, affecting ecological stability.

Males of many species compete with one another, allowing access to mating opportunities. During combat, contestants are constantly making decisions, e.g. to continue competing or retreat, based on the relative difference in resource holding potential (RHP) or some internal threshold. The outcome of these interactions is often based on the competitors RHP, which can be measured as the size of exaggerated traits (e.g. horns, mandibles, etc.) or overall body size. Competitive assessment models have been used to describe these behaviours and determine how animals assess their RHP and their opponent's RHP. This study looked at the contests of the Helm's stag beetle, Geodorcus helmsi, in a controlled laboratory environment. We found that larger males were more likely to win in an agonistic interaction and assumed that mandible length is a suitable proxy for RHP in this species. However, we did not find support for any assessment model being used in these contests. We also detail competitive behaviours of G. helmsi in a wild population for the first time. This study contributes to the research about the fighting behaviour in stag beetles and adds to the body of knowledge on New Zealand stag beetle behaviour, which has not been well studied.

Solitary bees (Hymenoptera: Insecta) are key pollinators for natural ecosystems and agricultural crops. Unlike social bees, such as bumblebees and honeybees, solitary bees forage and build their nests independently and are more vulnerable to ongoing threats, including habitat loss and pesticides, than social bees. New Zealand has 27 native solitary bee species, and understanding foraging and nestingbehaviours of native bees is critical for conservation efforts. However, few New Zealand studies have investigatedthe behavioural ecology of native bees. We looked at three native bee species in Dunedin: Lasioglossum sordidum (Halictidae), Nesocolletes fulvescens (syn. Leioproctus fulvescens), and Nesocolletes pekanui (syn. Leioproctus pekanui) (both Colletidae). These three native bee species were found at four urban nesting sites. Diurnal female nesting and foraging behaviours were observed and recorded regularly over a single summer. Both L. sordidum and N. fulvescens foraged more frequently and for longer periods in the morning than during midday and afternoon periods. Activity peaked when temperatures were between 20 degrees C and 25 degrees C at all four nesting sites. Wind speed significantly decreased general activity whereas ambient temperature significantly increased activity at one site. Additionally, both environmental factors influenced the number of nest entries and foraging trips of L. sordidum. Foraging trips of N . pekanui could last more than one hour, compared to L. sordidum and N. fulvescens, which foraged for c. 24 minutes on average before returning to the nest. In contrast, all three species spent similar lengths of time in the nest throughout the day. These findings contribute to an understanding of New Zealand native bees, but more research is needed to aid future conservation efforts.

IntroductionEpidemiological research has shown those with bipolar disorders (BD) are more likely to work in creative professions. The current work is the first to examine ambition, exploration versus exploitation ratio, and insensitivity to effort/rewards among individuals with and without BD in an Asian cultural context.MethodsWriters and visual artists from Hong Kong who were diagnosed with BD completed a questionnaire to assess lifetime creative accomplishments, a self-rated measure of ambition, and two laboratory-based tasks: the observe-or-bet task to detect exploration versus exploitation tendencies, and an effort discounting task to measure sensitivity to effort required and reward level.ResultsThe sample included 44 participants diagnosed with BD and 69 control participants, with 87 (77%) being female and an average age of 35.1 years (range: 18 to 65). Bayesian analyses found no group differences in creativity or related mechanisms between BD and control participants. However, decision tree algorithms revealed multivariate contributors to creative accomplishments. Replicating prior work, high ambition was key, with the most productive also willing to persevere despite high effort. Among lower-ambition individuals, control participants who engaged in balancing exploration versus exploitation had greater accomplishments. Importantly, there was no evidence that the effects of ambition or effort-based decision-making on creativity differed based on BD diagnosis. Bipolar group had lower socioeconomic status potentially impacting their self-rated creativity scores and creative potential. However, these findings remain tentative and await further investigation due to limited sample size.DiscussionThe findings suggest the mechanisms underlying creativity may not inherently differ for those with BD compared to controls. Ambition, especially when combined with effort and willingness, drives creative accomplishments. Strategic use of exploration versus exploitation was associated with greater creativity among less ambitious individuals without BD. A nuanced, multivariate approach is needed to understand the bipolar-creativity relationship across cultures. Study limitations included small sample size and over-representation of female participants.

BACKGROUND:A key goal of clinical neuroscience is to uncover reliable neurobiological targets for treatment. Urgency (negative or positive urgency subdomains, or N.urg/P.urg respectively), or affect-based impulsivity, is clinically relevant in bipolar disorder (BD). However, the neurocognitive correlates of positive and negative urgency have been mixed, with few considering the moderating effects of BD diagnosis and positive emotional context. METHODS:We conducted a 2 (group: BD vs. gender-matched healthy controls, or HC) by 2 (condition: positive vs. neutral affect) by 2 (task difficulty; within subjects) mixed, single-blind study. We examined neurocognitive correlates of urgency using EF performance and neuroimaging data from 74 participants (60 % females, Mage = 36). RESULTS:Between-group differences (HC > BD) in EF performance ranged from negligible to large (ηp2: 0 to 0.18). At the p < .05 threshold, positive urgency was correlated with lower cognitive control and working memory efficiency (r ranging from 0.25 to 0.34, p < .05). N.urg was correlated with reduced activity in the ventrolateral PFC (vlPFC) during cognitive control (r = -0.26 to -0.29, p < .05). Multivariate Analysis of Variance (MANOVA) and subsequent simple slopes analyses revealed significant moderation by emotional context and BD diagnosis. High N.urg predicted hypoactivity in the left orbitofrontal cortex in BD only, whereas high P.urg predicted hyperactivity in the right vlPFC in positive emotion context condition only. No correlations/MANOVA findings remained significant after p-value correction. CONCLUSION:Notwithstanding the study's limitations, the nature of the relationship between urgency and neurocognitive factors may be person- and context dependent.

BackgroundCognitive rigidity and working memory impairment are established features of internalizing syndromes. Growing evidence suggests that deficits in affective control –cognitive control in the context of emotion – may underpin elevated emotion-related impulsivity in various psychiatric disorders.ObjectiveThis study examines two components of affective control (affective flexibility and emotional working memory) as potential neurocognitive processes linking emotion-related impulsivity to internalizing psychopathology.MethodUndergraduate participants (analysis n = 120) completed the Memory and Affective Flexibility Task (MAFT), a novel behavioral assessment designed to assess hot cognition in affective flexibility and emotional working memory performance, alongside self-report measures of impulsivity and symptoms of internalizing disorders.ResultsStructural equation modeling suggested that less accurate working memory during neutral trials (cool cognition) was associated with more symptoms of internalizing psychopathology. However, effects of hot working memory and affective flexibility were not significantly related to emotion-related impulsivity or psychopathology scores.ConclusionsAlthough findings provide no support for the validity of MAFT indices of hot cognition, these results replicate and extend work on the importance of cool working memory and emotion-related impulsivity as correlates of psychopathology.

Misophonia is a disorder involving sensitivity to certain sounds and related stimuli. Here, we explore the relationship between misophonia and affective flexibility, which describes cognitive shifting abilities in the face of emotion-evoking stimuli. The secondary aim of this study is to test the potential association between misophonia and cognitive flexibility, building upon findings from previous research. The third objective is to examine the relationship between misophonia and rumination. One hundred and forty participants completed the Memory and Affective Flexibility Task (MAFT), designed to assess affective flexibility, as well as a battery of self-report measures to evaluate misophonia severity, cognitive flexibility, and rumination. Results suggested an inverse relationship between affective flexibility as measured by switch accuracy, but not reaction time, and misophonia severity. Cognitive flexibility was also inversely associated with misophonia severity, but was not attributed to task-based affective flexibility, suggesting two independent constructs both involved in misophonia manifestation. Rumination associated positively with misophonia severity and inversely with cognitive flexibility, but not affective flexibility. Taken together, these findings highlight a unique cognitive profile of misophonia, characterized by rigidity at the psychological level through cognitive inflexibility and rumination, as well as at the executive function level in terms of affective switching difficulties.

Background Inhibitory deficits are common in psychopathology. Emotion-related impulsivity (ERI) and rumination are general risk factors for psychiatric distress that are similarly associated with dysfunctional inhibition—particularly in affective contexts. A number of cognitive remediation procedures have been developed to improve inhibitory control; however, most remediation programs focus on “cold” cognition independent of affective processing. This pilot trial will gather preliminary evidence for a new cognitive training intervention targeting “hot” affective control (ie, inhibitory functions during elevated emotional arousal) in a transdiagnostic sample of adults who report heightened emotion dysregulation. Objective This manuscript describes a protocol for a pilot randomized waitlist-controlled trial to assess changes in ERI and rumination after neurobehavioral affective control training (N-ACT), an 8-week cognitive training intervention designed to improve emotional response inhibition and emotional working memory. Our primary aim is to evaluate the efficacy, feasibility, and acceptability of N-ACT in reducing rumination and ERI, which we respectively conceptualize as complementary cognitive and behavioral consequences of emotion dysregulation. Secondarily, we will examine whether N-ACT leads to improvements in inhibitory control and, more distally, psychopathology symptoms. Methods The final sample will comprise 80 adults who report high ERI or rumination. Participants will be randomized to (1) begin the N-ACT program without delay or (2) join a waitlist condition and then complete N-ACT. Exclusion criteria include active alcohol or substance use disorders, psychosis, and suicide risk. At the baseline and postintervention time points, participants will complete measures of emotion dysregulation and psychiatric symptoms, as well as a neuropsychological assessment of inhibitory control. Individuals assigned to the control group will undergo an identical assessment before joining the waitlist, followed by parallel assessments before and after N-ACT. Results This trial is funded by support from the University of California Board of Regents and the Peder Sather Foundation (funding period: October 2022-September 2025). Recruitment is scheduled to begin in spring 2025. We will begin data analysis once data collection is complete, which is planned to occur in fall 2025. Conclusions This pilot randomized waitlist-controlled trial is designed to assess the initial efficacy, feasibility, and acceptability of N-ACT, a novel cognitive remediation approach developed to address 2 key contributors to psychopathology: ERI and rumination. The N-ACT program uses computerized adaptive behavioral tasks to strengthen the affective control processes theoretically and empirically linked to ERI and rumination. We hope this work will help inform future studies with sufficient statistical power to ascertain whether enhancing affective control through cognitive training (N-ACT) produces downstream reductions in psychiatric symptoms via improved emotion regulation. Trial Registration ClinicalTrials.gov NCT06226467; https://www.clinicaltrials.gov/study/NCT06226467; Open Science Framework Registry rak5z; https://osf.io/rak5z International Registered Report Identifier (IRRID) PRR1-10.2196/54221

OBJECTIVES:The interpersonal-psychological theory of suicide identifies three risk factors for suicidal behaviours: perceived burdensomeness, thwarted belongingness, and acquired capability. We sought to clarify relationships between the interpersonal-psychological risk factors and two individual difference factors, emotion-related impulsivity (ERI) and intolerance of uncertainty (IU). METHODS:In the current study, we analysed self-report scales from a large community sample (N = 169) that was oversampled for individuals with elevated suicidality. We considered two separate factors of ERI: Pervasive Influence of Feelings, which measures how much a person's emotions shape their worldview, and Feelings Trigger Action, which measures impulsive behavioural reactivity to emotions. We tested unique effects of ERI and IU and the interactions of ERI × IU on the three interpersonal-psychological risk factors using linear regression models. RESULTS:Pervasive Influence of Feelings correlated with higher perceived burdensomeness and thwarted belongingness, whereas Feelings Trigger Action correlated with higher perceived burdensomeness and acquired capability. Within the regression models, IU correlated significantly with lower acquired capability but not perceived burdensomeness or thwarted belongingness. Interactions of ERI × IU were not significant. CONCLUSIONS:These results demonstrate the importance of considering both factors of ERI in understanding the risk for suicide. Our results also provide novel evidence that while IU may not impact risk factors such as perceived burdensomeness and thwarted belongingness, higher levels of IU may serve as some protection against individuals' acquired capability for suicidal action. Limitations and implications of findings are discussed.

Electrodermal activity (EDA) has been shown to reflect a physiological index of many cognitive processes, such as attention, orientation, and working memory. Crider (2008) has argued that EDA lability may index ability to successfully employ cognitive control so as to down-regulate emotion. We test this model by considering whether EDA lability would relate to emotion-related impulsivity and aggression, as well as cognitive control measured by the antisaccade task in a sample of 221 participants selected for a broad range of internalizing and externalizing syndromes. Baseline EDA was gathered at baseline, and task EDA was gathered during the antisaccade task. Partial correlation models controlled for prosaccade gaze accuracy in considering the association of EDA and antisaccade performance. Emotion-related impulsivity was unrelated to EDA indices. We discuss methodological and conceptual issues with regards to the nonconvergence of psychophysiological (EDA) indices with behavioral and self-report measures, and address challenges in identifying lab-based correlates of longer-term individual differences in aggression or impulsivity.

BACKGROUND:Emotion-related impulsivity (ERI) describes the trait-like tendency toward poor self-control when experiencing strong emotions. ERI has been shown to be elevated across psychiatric disorders and predictive of the onset and worsening of psychiatric syndromes. Recent work has correlated ERI scores with the region-level neuroanatomical properties of the orbitofrontal cortex (OFC), but not posteromedial cortex (PMC). Informed by a growing body of research indicating that examining the morphology of specific cortical folds (sulci) can produce unique insights into behavioral outcomes, the present study modeled the association between ERI and the morphology of sulci within OFC and PMC, which is a finer scale than previously conducted. METHODS:Analyses were conducted in a transdiagnostic sample of 118 adult individuals with a broad range of psychiatric syndromes. First, we manually defined over 4,000 sulci across 236 cerebral hemispheres. Second, we implemented a model-based LASSO regression to relate OFC sulcal morphology to ERI. Third, we tested whether effects were specific to OFC sulci, sulcal depth, and ERI (as compared to PMC sulci, sulcal gray matter thickness, and non-emotion-related impulsivity). RESULTS:The LASSO regression revealed bilateral associations of ERI with the depths of eight OFC sulci. These effects were strongest for OFC sulci, sulcal depth, and ERI in comparison to PMC sulci, sulcal gray matter thickness, and non-emotion-related impulsivity. In addition, we identified a new transverse component of the olfactory sulcus in every hemisphere that is dissociable from the longitudinal component based on anatomical features and correlation with behavior, which could serve as a new transdiagnostic biomarker. CONCLUSIONS:The results of this data-driven investigation provide greater neuroanatomical and neurodevelopmental specificity on how OFC is related to ERI. As such, findings link neuroanatomical characteristics to a trait that is highly predictive of psychopathology.

Understanding the key pollinators of rare plants is important for a holistic assessment of ecosystem health, as the impact on a given species can travel through the network, affecting other species. Many specialist calcicolous (limestone-specific) plants are rare. Conservation management plans have been developed to assist in the survival of these rare plant species, but these rarely include information on pollinators. To increase our understanding of limestone ecosystem functioning, we investigated the pollinators of three critically threatened plant species, Lepidium sisymbrioides, Carmichaelia hollowayi, and Gentianella calcis subsp. calcis in two Otekaike limestone reserves, Wai O Toura Scenic Reserve and Waipata Scientific Reserve. We used community sampling and 10-minute observations to investigate which insect species are the most likely pollinators of these three plants species. Observed flower visitors were caught, identified, and swabbed for pollen. The ability to deposit conspecific pollen on stigmas was tested for selected insect species via single-pollinator visit assays to female L. sisymbrioides flowers. The community sampling experiments show that the most likely pollinators of L. sisymbrioides are the endemic bee, Lasioglossum sordidum, and Tachinid flies, including native Pales sp., and endemic Mallochomacquartia vexata. The most likely pollinator for G. calcis subsp. calcis is the endemic hover fly, Melanostoma fasciatum. This species was the most frequent visitor, with over half the hover flies captured carrying G. calcis subsp. calcis pollen. The native bee Leioproctus pango is the most likely pollinator for C. hollowayi, as it was the most observed visitor and nearly all captured bees were carrying C. hollowayi pollen. This research contributes to the literature on New Zealand's naturally uncommon ecosystems and provides an in-depth look into plant-pollinator interactions of these under-researched plant species.

Research using zebrafish (Danio rerio) has begun to provide novel information in many fields, including the behavioral pharmacology of drug use and misuse. There have been limited studies on the effects of methamphetamine in adult zebrafish and the parameters of exposure (dose, test session length) have not been well-documented. Behavior following drug exposure is generally measured during relatively short sessions (6-10 min is common) in a novel tank environment. Many procedural variables (isolation, netting, novel tank) elicit anxiety-like behavior that is most apparent during the initial portion of a test session. This anxiety-like behavior might mask the initial effects of methamphetamine. During longer test sessions, these anxiety-like responses would be expected to habituate and drug effects should become more apparent. To test this idea, we measured several locomotor activity responses for 50-min following a range of methamphetamine doses (0.1-3.0 mg/L via immersion in methamphetamine solution). Methamphetamine failed to alter swimming velocity, distance travelled, or freezing time. In contrast, methamphetamine produced a dose-dependent decrease in time spent in the bottom of the tank, an increase in the number of visits to the top of the tank, and an increase in the number of transitions along the sides of the tank. The effects of methamphetamine were apparent 10-20 min following exposure and generally persisted throughout the session. These findings indicate that longer test sessions are required to measure methamphetamine-induced changes in behavior in zebrafish, as has been shown in other laboratory animals. The results also suggest that anxiety-like responses associated with various procedural aspects (netting, isolation, novel test apparatus) likely interfere with the ability to observe many behavioral effects of methamphetamine in zebrafish. Based on the current results, habituation to testing procedures to reduce anxiety-like behaviors is recommended in determining the effects of methamphetamine in zebrafish.

IntroductionUrgency has been defined as the tendency towards rash speech and behavior in the context of emotion. Measures of Urgency have been found to have robust predictive power for psychopathologies and problematic behaviors. In the current study, we question whether emotions are unique drivers of urgency, or if emotions are potent exemplars of contexts that lead to rash speech and behavior. The Emotion Specific model and the Broader Contexts model correspond with these two conceptualizations of urgency, and they frame our pre-registered hypotheses.MethodsParticipants from two well-powered samples (n = 600,n = 588) completed 9 modified items from the Urgency and Positive Urgency scales to assess rash responses in each of four contexts – “Upset,” “Excited,” “Tired,” and “Hungry” – and a fifth “In General” set. After data cleaning, we used principal components analysis to construct a unidimensional, 4-item set that was applied to capture impulsive behavior across the five contexts.ResultsWe found that this research tool, called the Contexts of Impulsive Behaviors (CIBS), replicated in the second dataset, and it had adequate internal reliability in both samples. Although the Emotion Specific model was supported by the fact that the Upset context had a greater mean and greater variance than the Tired and Hungry contexts, most results supported the Broader Contexts model. That is, CIBS contexts were highly intercorrelated, and bivariate correlations with psychopathology were not significantly different across contexts. In partial correlations, effects of the Upset and Excited contexts were partially or fully statistically mediated by the Tired and Hungry contexts.DiscussionThese findings suggest that emotions are potent contexts for impulsive behaviors. At the same time, those with high urgency are vulnerable to impulsivity in other contexts, such as fatigue and hunger, that challenge the regulatory functions of the prefrontal cortex. Limitations, future directions, and clinical implications are discussed.

Abstract Background The primary objective of this trial is to examine the mechanisms of time-restricted eating (TRE) as an adjunct to psychiatric care for people with bipolar disorder (BD) with sleep or circadian disruptions. This study builds on prior studies of circadian disruption in BD as well as growing evidence that TRE improves circadian functioning. Methods One-hundred fifty participants diagnosed with BD 1 or II will be recruited via advertising in the local community. Main inclusion criteria include: obtaining medical treatment for BD; current sleep or circadian problems; self-reported eating period of ≥ 12 h; no eating disorder or other health conditions that would hinder or limit the safety of following TRE; and not currently experiencing a mood episode, acute suicidality, psychosis, alcohol or substance use disorder. Participants will be asked to complete a baseline period in which daily food intake is logged online for two weeks. After baseline, participants will be asked to follow TRE for 8 weeks and to continue to complete daily food logging during this time. Symptom severity interviews will be conducted by phone or videoconference at baseline, mid-intervention (6 weeks post-baseline), end of intervention (10 weeks post-baseline), and 6 months post-baseline. Self-rated symptom severity and quality of life data will be gathered online at the same time points as symptom severity interviews, and at 16 weeks post-baseline (6 weeks after the TRE period ends). To assess potential mechanisms of change, we will examine the change in diurnal amplitude of ‘clock’ gene expression as a primary mediator at 8 weeks compared to baseline. We will further test whether diurnal amplitude of clock gene expression is predictive above and beyond the role of two covariate potential mediators, glucose tolerance and inflammation at 8 weeks relative to baseline. To provide an index of whether TRE successfully decreases emotional lability, participants will be asked to complete 5 mood assessments per day for 7 days at baseline and at 10 weeks. These mood assessments will be optional. Discussion The planned research will provide novel and important information on whether TRE improves sleep/circadian rhythm problems, along with reductions in mood symptoms and improvements in quality of life, for individuals with BD. Trial registration ClinicalTrials.gov ID: NCT06555406.

Abstract Background The primary objective of this randomized controlled trial (RCT) is to establish the effectiveness of time-restricted eating (TRE) compared with the Mediterranean diet for people with bipolar disorder (BD) who have symptoms of sleep disorders or circadian rhythm sleep–wake disruption. This work builds on the growing evidence that TRE has benefits for improving circadian rhythms. TRE and Mediterranean diet guidance will be offered remotely using self-help materials and an app, with coaching support. Methods This study is an international RCT to compare the effectiveness of TRE and the Mediterranean diet. Three hundred participants will be recruited primarily via social media. Main inclusion criteria are: receiving treatment for a diagnosis of BD I or II (confirmed via DIAMOND structured diagnostic interview), endorsement of sleep or circadian problems, self-reported eating window of ≥ 12 h, and no current mood episode, acute suicidality, eating disorder, psychosis, alcohol or substance use disorder, or other health conditions that would interfere with or limit the safety of following the dietary guidance. Participants will be asked to complete baseline daily food logging for two weeks and then will be randomly allocated to follow TRE or the Mediterranean diet for 8 weeks, during which time, they will continue to complete daily food logging. Intervention content will be delivered via an app. Symptom severity interviews will be conducted at baseline; mid-intervention (4 weeks after the intervention begins); end of intervention; and at 6, 9, and 15 months post-baseline by phone or videoconference. Self-rated symptom severity and quality of life data will be gathered at those timepoints, as well as at 16 weeks post baseline. To provide a more refined index of whether TRE successfully decreases emotional lability and improves sleep, participants will be asked to complete a sleep diary (core CSD) each morning and complete six mood assessments per day for eight days at baseline and again at mid-intervention. Discussion The planned research will provide novel and important information on whether TRE is more beneficial than the Mediterranean diet for reducing mood symptoms and improving quality of life in individuals with BD who also experience sleep or circadian problems. Trial registration ClinicalTrials.gov ID NCT06188754.

Male reproductive traits such as ejaculate size and quality, are expected to decline with advancing age due to senescence. It is however unclear whether this expectation is upheld across taxa. We perform a meta-analysis on 379 studies, to quantify the effects of advancing male age on ejaculate traits across 157 species of non-human animals. Contrary to predictions, we find no consistent pattern of age-dependent changes in ejaculate traits. This result partly reflects methodological limitations, such as studies sampling a low proportion of adult lifespan, or the inability of meta-analytical approaches to document non-linear ageing trajectories of ejaculate traits; which could potentially lead to an underestimation of senescence. Yet, we find taxon-specific differences in patterns of ejaculate senescence. For instance, older males produce less motile and slower sperm in ray-finned fishes, but larger ejaculates in insects, compared to younger males. Notably, lab rodents show senescence in most ejaculate traits measured. Our study challenges the notion of universal reproductive senescence, highlighting the need for controlled methodologies and a more nuanced understanding of reproductive senescence, cognisant of taxon-specific biology, experimental design, selection pressures, and life-history.