The sex of organ geometry.

Organs have a distinctive yet often overlooked spatial arrangement in the body1-5. We propose that there is a logic to the shape of an organ and its proximity to its neighbours. Here, by using volumetric scans of many Drosophila melanogaster flies, we develop methods to quantify three-dimensional features of organ shape, position and interindividual variability. We find that both the shapes of organs and their relative arrangement are consistent yet differ between the sexes, and identify unexpected interorgan adjacencies and left-right organ asymmetries. Focusing on the intestine, which traverses the entire body, we investigate how sex differences in three-dimensional organ geometry arise. The configuration of the adult intestine is only partially determined by physical constraints imposed by adjacent organs; its sex-specific shape is actively maintained by mechanochemical crosstalk between gut muscles and vascular-like trachea. Indeed, sex-biased expression of a muscle-derived fibroblast growth factor-like ligand renders trachea sexually dimorphic. In turn, tracheal branches hold gut loops together into a male or female shape, with physiological consequences. Interorgan geometry represents a previously unrecognized level of biological complexity which might enable or confine communication across organs and could help explain sex or species differences in organ function.

Enteric neurons increase maternal food intake during reproduction.

Reproduction induces increased food intake across females of many animal species1-4, providing a physiologically relevant paradigm for the exploration of appetite regulation. Here, by examining the diversity of enteric neurons in Drosophila melanogaster, we identify a key role for gut-innervating neurons with sex- and reproductive state-specific activity in sustaining the increased food intake of mothers during reproduction. Steroid and enteroendocrine hormones functionally remodel these neurons, which leads to the release of their neuropeptide onto the muscles of the crop-a stomach-like organ-after mating. Neuropeptide release changes the dynamics of crop enlargement, resulting in increased food intake, and preventing the post-mating remodelling of enteric neurons reduces both reproductive hyperphagia and reproductive fitness. The plasticity of enteric neurons is therefore key to reproductive success. Our findings provide a mechanism to attain the positive energy balance that sustains gestation, dysregulation of which could contribute to infertility or weight gain.

A combination of Notch signaling, preferential adhesion and endocytosis induces a slow mode of cell intercalation in the Drosophila retina.

Movement of epithelial cells in a tissue occurs through neighbor exchange and drives tissue shape changes. It requires intercellular junction remodeling, a process typically powered by the contractile actomyosin cytoskeleton. This has been investigated mainly in homogeneous epithelia, where intercalation takes minutes. However, in some tissues, intercalation involves different cell types and can take hours. Whether slow and fast intercalation share the same mechanisms remains to be examined. To address this issue, we used the fly eye, where the cone cells exchange neighbors over ∼10 h to shape the lens. We uncovered three pathways regulating this slow mode of cell intercalation. First, we found a limited requirement for MyosinII. In this case, mathematical modeling predicts an adhesion-dominant intercalation mechanism. Genetic experiments support this prediction, revealing a role for adhesion through the Nephrin proteins Roughest and Hibris. Second, we found that cone cell intercalation is regulated by the Notch pathway. Third, we show that endocytosis is required for membrane removal and Notch activation. Taken together, our work indicates that adhesion, endocytosis and Notch can direct slow cell intercalation during tissue morphogenesis.

Examining the impact of major life events on the frequency and experience of daily social events.

OBJECTIVE: Life events can impact people's dispositional functioning by changing their state-level patterns of thoughts, feelings, and behavior. One pathway through which this change may be facilitated is changes in the experience of daily social events. METHOD: We examined the dynamic relationship between major life events and the subsequent experience of positive and negative daily social events in a year-long longitudinal study (initial N = 1247). RESULTS: Experiencing positive and negative major life events moderated the effects of positive and negative social events on event-contingent state well-being and ill-being in ways that were mostly (but not always) consistent with both endowment and contrast effects on judgments of well-being. Furthermore, negative life events predicted an increase in the subsequent trajectory of negative social events, while the experience of daily ill-being predicted the subsequent experience of negative social events. CONCLUSIONS: These findings highlight the possible impact of major life events by explaining how they shape the subsequent experience of daily social events.

BAcTrace, a tool for retrograde tracing of neuronal circuits in Drosophila.

Animal behavior is encoded in neuronal circuits in the brain. To elucidate the function of these circuits, it is necessary to identify, record from and manipulate networks of connected neurons. Here we present BAcTrace (Botulinum-Activated Tracer), a genetically encoded, retrograde, transsynaptic labeling system. BAcTrace is based on Clostridium botulinum neurotoxin A, Botox, which we engineered to travel retrogradely between neurons to activate an otherwise silent transcription factor. We validated BAcTrace at three neuronal connections in the Drosophila olfactory system. We show that BAcTrace-mediated labeling allows electrophysiological recording of connected neurons. Finally, in a challenging circuit with highly divergent connections, BAcTrace correctly identified 12 of 16 connections that were previously observed by electron microscopy.

Trauma exposure and short-term volitional personality trait change.

OBJECTIVE: Research into post-traumatic growth (PTG) finds individuals report positive changes in their identity, relationships, and worldviews after trauma. In a pre-registered 16-week longitudinal study, we examined trait change after recent trauma exposure to test an operationalization of PTG as positive personality change. We examined the influence of intrapersonal and social factors including motivation to change traits, perceived social support, and event centrality. METHOD: Participants (n = 1004) reported on trauma exposure in past 1-month, centrality of each traumatic event, and social support. Participants with trauma exposure (n = 146) and a matched control group reported on their traits in 8 waves at 2-week intervals, and motivation to change traits in 3 waves. RESULTS: Although some trait change was observed, it was not consistent with PTG. We found agreeableness declined in the trauma relative to the control group among participants who did not want to change in this trait. Conscientiousness declined for individuals with highly central traumas. Social support predicted increases in emotional stability, conscientiousness, and openness but only for individuals in the control group. CONCLUSIONS: We discuss the value of defining PTG as positive trait change and suggest future directions including assessment of facet-level changes and ideographic methods.

Do We Know Whether We're Happier? Corroborating Perceived Retrospective Assessments of Improvements in Well-Being.

To what extent do our beliefs about how our well-being has improved over time correspond to observed changes? Participants (N = 1,247 from Qualtrics Panels) completed questionnaires measuring dispositional well-being and ill-being (depressive symptoms) at three time points over the course of one year, as well as 44 weekly assessments of state well-being and ill-being over 52 weeks. They additionally completed measures of perceived improvements in well-being and ill-being at Weeks 45 and 52 as well as a measure of broad personality traits. We estimated latent change scores and latent growth curves, which allowed us to obtain more accurate estimates of the convergence between retrospective improvements and veridical change compared to past methods utilized. Stability in both global and state well-being and ill-being were observed. People who agreed more strongly that their well-being had improved (or their ill-being had increased) tended to show greater increases in actual well-being (or ill-being) across the past year. Additionally, we observed meaningful relationships between personality traits and perceived improvements. On average, people have some insight in assessing whether they became happier (or unhappier) over one year.

Post-traumatic growth as positive personality change: Challenges, opportunities, and recommendations.

OBJECTIVE: Post-traumatic growth typically refers to enduring positive psychological change experienced as a result of adversity, trauma, or highly challenging life circumstances. Critics have challenged insights from much of the prior research on this topic, pinpointing its significant methodological limitations. In response to these critiques, we propose that post-traumatic growth can be more accurately captured in terms of personality change-an approach that affords a more rigorous examination of the phenomenon. METHOD: We outline a set of conceptual and methodological questions and considerations for future work on the topic of post-traumatic growth. RESULTS: We provide a series of recommendations for researchers from across the disciplines of clinical/counseling, developmental, health, personality, and social psychology and beyond, who are interested in improving the quality of research examining resilience and growth in the context of adversity. CONCLUSION: We are hopeful that these recommendations will pave the way for a more accurate understanding of the ubiquity, durability, and causal processes underlying post-traumatic growth.

Validation of the Parental Facilitation of Mastery Scale-II.

OBJECTIVE: To develop a more reliable and comprehensive version of the Parental Facilitation of Mastery Scale (PFMS) METHOD: In Study 1, 387 undergraduates completed an expanded PFMS (PFMS-II) and measures of parenting, perceived control, responses to early life challenges, and psychopathology. In Study 2, 182 trauma-exposed community participants completed the PFMS-II and measures of perceived control, psychopathology, and well-being RESULTS: In Study 1, exploratory factor analysis of the PFMS-II revealed two factors. These factors replicated in Study 2; one item was removed to achieve measurement invariance across race. The final PFMS-II comprised a 10-item overprotection scale and a 7-item challenge scale. In both samples, this measure demonstrated good convergent and discriminant validity and was more reliable than the original PFMS. Parental challenge was a unique predictor of perceived control in both samples CONCLUSION: The PFMS-II is a valid measure of important parenting behaviors not fully captured in other measures.

Wisdom Gained? Assessing Relationships Between Adversity, Personality and Well-Being Among a Late Adolescent Sample.

How do late adolescents make sense of stressful life events they have experienced in their lives? In a sample of 1320 college students, 676 (58% White, 63% female) reported the stressful events they had experienced in their lifetime up until the present survey and indicated whether they considered each stressful event to be a turning point and/or an opportunity for wisdom. Students also completed measures of personality and well-being. We hypothesized that the tendency to interpret stressful events as turning points or opportunities for wisdom would explain the associations between three personality characteristics (Openness to Experience, Extraversion, and Emotionality) and well-being. We used a multi-step ESEM approach in which we first assessed the measurement structure of our items before testing partial and complete structural models. We tested partial and structural models according to extant guidelines associated with the evaluation of indirect effects models. We did not find support for the indirect effects model, but Openness was associated with the tendency to view stressful events as turning points, and Openness and Extraversion were associated with the tendency to view stressful events as leading to wisdom, as well as with increased well-being.

Personality science, resilience, and posttraumatic growth.

PASTOR represents an innovative development in the study of resilience. This commentary highlights how PASTOR can help both clarify critical questions in and benefit from engaging with new research in personality science on behavioral flexibility across situations in addition to stability over time, and also clarify the relationship between resilience and posttraumatic growth.

Daily emotional dynamics and changes in posttraumatic growth and posttraumatic depreciation among people living with HIV.

OBJECTIVE: Posttraumatic growth (PTG), and its negative reflection, posttraumatic depreciation (PTD), are two aspects of response to trauma. This study explores whether daily emotional dynamics (inertia and innovation) can translate into positive versus negative changes among people living with HIV (PLWH) in the form of long-term changes in PTG or PTD. METHODS: The study combined a classical longitudinal approach with two assessments of PTG and PTD within one year and a measurement burst diary design with three weekly electronic diaries. In total, 249 PLWH participated in this study, filling out an expanded version of the Posttraumatic Growth and Depreciation Inventory (PTGDI-X) and a survey of sociodemographic and clinical data. In addition, they assessed their positive affect (PA) and negative affect (NA) at the end of each day in online diaries using a shortened version of the PANAS-X. RESULTS: Although we observed stable significant inertia and innovation of PA and NA across all bursts, these parameters of daily emotional dynamics were unrelated to the longitudinal changes in PTG and PTD. The same null results were also noted for the average levels of NA and PA. CONCLUSIONS: The results indicated the relative stability of emotion regulation in PLWH over the course of one year and contributed to understanding its dynamic mechanisms in terms of trait-like characteristics. The null result of the relationship between the PTG and PTD change might suggest a weak role of emotion regulation in shaping these trajectories as well as a lack of validity of the PTG/PTD measures.

A Theoretical Qualitative Investigation Exploring Illness Perceptions and Decision-Making About COVID-19 in an Ethnically Diverse UK-Based Sample.

Purpose: The primary aim of the present investigation was to explore perceptions, experiences, and decision-making relating to the COVID-19 illness as the UK entered into a phase of "living safely with COVID-19". A secondary aim was to explore how perceptions around the COVID-19 vaccine might vary by ethnicity. Participants and Methods: We adopted a qualitative approach with a diverse sample of UK-based participants. One-hundred-and-ninety-three individuals completed an online survey measuring perceptions towards COVID-19 with questions conceptualized through the Common-Sense Model of Self-Regulation. Results: Through deductive thematic analysis we identified one overarching theme in our data, "The transition back to normal routines", with four themes illustrating individuals' perceptions and experiences with COVID-19: 1) "Living with the uncertainty", 2) "Concern for others", 3) "The multiple consequences of COVID-19", and 4) "Sense of control", with the sub-theme of "Should I vaccinate, should I not vaccinate?". Conclusion: Findings from the present investigation provide key insights for understanding how people's perceptions of COVID-19 during this transition period might impact their decisions and behavior moving forward. Specifically, findings suggest some prevailing concerns around catching the virus, while no strong qualitative evidence for concerns over long COVID were identified in this sample, the responsibility felt by individuals towards taking their own precautionary measures in light of the easing of all national restrictions, and some potential differences in perceptions towards the vaccine between individuals from different ethnic backgrounds.

Examining the protective function of perceptions of post-traumatic growth against entrapment and suicidal ideation.

BACKGROUND: Recent evidence has found that reporting post-traumatic growth (PTG) from a past stressful life event is associated with lower reports of suicidal ideation. Perceptions of PTG measure the extent to which an individual reports positive changes in their identity, relationships, and worldviews after a stressful event. However, little is known about how perceptions of PTG interact with feelings of defeat and entrapment to influence suicidal ideation. The current study examined this question through the Integrated Motivational-Volitional (IMV) Model of Suicidal Behavior. METHODS: 521 adult participants (315 females with age range of 18-82, M = 30.4 years, SD = 13.6) completed an online cross-sectional questionnaire with defeat, entrapment, suicidal ideation, PTG, depression and anxiety measures. Hypotheses and data analysis plans were pre-registered prior to data collection. RESULTS: PTG negatively correlated with defeat, entrapment and suicidal ideation. PTG predicted lower suicidal ideation when controlling for entrapment, depression and anxiety. PTG did not moderate the relationship between defeat on entrapment or the relationship between entrapment on suicidal ideation. LIMITATIONS: The findings were based on cross-sectional data where participants recalled experiences of defeat, entrapment and suicidal ideation from the past year. The sample was a large community (non-clinical) sample, and most of the participants identified as white (85%). CONCLUSION: Although PTG did not function as a moderator within the IMV model of suicidality, it predicted lower suicidal ideation while controlling for other known predictors of suicidal ideation. Future research could explore the function of PTG in appraisal-based models of suicidality.

Examining the protective influence of posttraumatic growth on interpersonal suicide risk factors in a 6-week longitudinal study.

Research has found an inverse relationship between posttraumatic growth (PTG) and suicidal ideation in military and community samples that holds when controlling for other suicide risk factors. However, further research is needed into the underlying mechanisms to clarify how PTG protects against the formation of suicidal ideation. The current two-wave longitudinal study examined whether perceiving PTG from recent adverse circumstances while in a national lockdown during the COVID-19 pandemic attenuated the positive relationship of two interpersonal suicide risk factors - perceived burdensomeness (PB) and thwarted belonginess (TB)-over 6 weeks. Participants (n = 170) were recruited online from Prolific from income-deprived areas in the United Kingdom (mean age = 37.65; SD = 12.50; 53.5% female). Post-hoc power analyses indicated we had insufficient power to examine the hypothesised mediation for TB. We examined whether PTG mediated the relationship between PB at wave 1 and wave 2 while controlling for depression and anxiety in a sample of individuals at-risk for suicidal ideation. PTG did significantly and partially mediate the positive relationship between PB at wave 1 and 2. We discuss the theoretical and clinical implications that could result if future research successfully replicates these initial exploratory findings.

Investigating corroboration of self-perceived posttraumatic growth among Sri Lankan Tamil survivors of ethnopolitical warfare through trait, domain, and profile agreement approaches.

Though research on assessing posttraumatic growth has been severely critiqued, some evidence suggests close others can observe and report changes in individuals following traumatic life events and are sensitive to idiosyncratic ways in which changes manifest. We extended these findings by investigating corroboration of self-perceived posttraumatic growth (PTG) and depreciation (PTD) as measured by the Posttraumatic Growth Inventory-42 (PTGI-42) among Sri Lankan Tamil war survivors (n = 200). Informants slightly corroborated overall levels of PTG and PTD, while a more nuanced profile analysis procedure revealed overall-but not distinctive-profile agreement. This suggests self-other agreement is modest and may partly reflect shared narratives and collective cultural understandings about how people change after trauma. Results demonstrate further that informants were not sensitive to idiosyncratic ways in which target individuals had changed. Together, the lack of validity evidence suggests that the PTGI-42 may be inadequate in some cross-cultural contexts as a measure of nuanced posttraumatic change (i.e., as a measure of specific changes in the five theorized domains of growth and depreciation). Future work should emphasize culture- and context-sensitive measurement of posttraumatic change, particularly focusing on methods other than retrospective self-reports, such as prospective longitudinal designs. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Antigen retrieval and clearing for whole-organ immunofluorescence by FLASH.

Advances in light-sheet and confocal microscopy now allow imaging of cleared large biological tissue samples and enable the 3D appreciation of cell and protein localization in their native organ environment. However, the sample preparations for such imaging are often onerous, and their capability for antigen detection is limited. Here, we describe FLASH (fast light-microscopic analysis of antibody-stained whole organs), a simple, rapid, fully customizable technique for molecular phenotyping of intact tissue volumes. FLASH utilizes non-degradative epitope recovery and membrane solubilization to enable the detection of a multitude of membranous, cytoplasmic and nuclear antigens in whole mouse organs and embryos, human biopsies, organoids and Drosophila. Retrieval and immunolabeling of epithelial markers, an obstacle for previous clearing techniques, can be achieved with FLASH. Upon volumetric imaging, FLASH-processed samples preserve their architecture and integrity and can be paraffin-embedded for subsequent histopathological analysis. The technique can be performed by scientists trained in light microscopy and yields results in <1 week.

Food, microbes, sex and old age: on the plasticity of gastrointestinal innervation.

The gastrointestinal tract is innervated by its own enteric nervous system and by extrinsic neurons that connect it with the central nervous system. Innervation allows the gastrointestinal tract to sense and respond to diverse stimuli, adjusting motility and secretion, but also affecting our physiology, behaviour and immunity. The mechanisms underlying the formation of gastrointestinal neurons are beginning to be elucidated; those that keep them plastic over an organism's lifetime remain to be explored. Here, we review the effects of microbiota, nutrients, sex and ageing on the morphology and function of gastrointestinal innervation in mammals, and discuss how this plasticity shapes gut-brain crosstalk and whole-body physiology. We also highlight insights gained by nascent studies of the enteric innervation of Drosophila melanogaster.

Cell-type-specific mechanical response and myosin dynamics during retinal lens development in Drosophila.

During organogenesis, different cell types need to work together to generate functional multicellular structures. To study this process, we made use of the genetically tractable fly retina, with a focus on the mechanisms that coordinate morphogenesis between the different epithelial cell types that make up the optical lens. Our work shows that these epithelial cells present contractile apical-medial MyosinII meshworks, which control the apical area and junctional geometry of these cells during lens development. Our study also suggests that these MyosinII meshworks drive cell shape changes in response to external forces, and thus they mediate part of the biomechanical coupling that takes place between these cells. Importantly, our work, including mathematical modeling of forces and material stiffness during lens development, raises the possibility that increased cell stiffness acts as a mechanism for limiting this mechanical coupling. We propose this might be required in complex tissues, where different cell types undergo concurrent morphogenesis and where averaging out of forces across cells could compromise individual cell apical geometry and thereby organ function.