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A negative shift in the calcium isotopic composition of marine carbonate rocks spanning the end-Permian extinction horizon in South China has been used to argue for an ocean acidification event coincident with mass extinction. This interpretation has proven controversial, both because the excursion has not been demonstrated across multiple, widely separated localities, and because modeling results of coupled carbon and calcium isotope records illustrate that calcium cycle imbalances alone cannot account for the full magnitude of the isotope excursion. Here, we further test potential controls on the Permian-Triassic calcium isotope record by measuring calcium isotope ratios from shallow-marine carbonate successions spanning the Permian-Triassic boundary in Turkey, Italy, and Oman. All measured sections display negative shifts in δ44/40Ca of up to 0.6‰. Consistency in the direction, magnitude, and timing of the calcium isotope excursion across these widely separated localities implies a primary and global δ44/40Ca signature. Based on the results of a coupled box model of the geological carbon and calcium cycles, we interpret the excursion to reflect a series of consequences arising from volcanic CO2 release, including a temporary decrease in seawater δ44/40Ca due to short-lived ocean acidification and a more protracted increase in calcium isotope fractionation associated with a shift toward more primary aragonite in the sediment and, potentially, subsequently elevated carbonate saturation states caused by the persistence of elevated CO2 delivery from volcanism. Locally, changing balances between aragonite and calcite production are sufficient to account for the calcium isotope excursions, but this effect alone does not explain the globally observed negative excursion in the δ13C values of carbonate sediments and organic matter as well. Only a carbon release event and related geochemical consequences are consistent both with calcium and carbon isotope data. The carbon release scenario can also account for oxygen isotope evidence for dramatic and protracted global warming as well as paleontological evidence for the preferential extinction of marine animals most susceptible to acidification, warming, and anoxia.

The geological calcium cycle is linked to the geological carbon cycle through the weathering and burial of carbonate rocks. As a result, calcium (Ca) isotope ratios (44Ca/40Ca, expressed as δ44/40Ca) can help to constrain ancient carbon cycle dynamics if Ca cycle behavior can be reconstructed. However, the δ44/40Ca of carbonate rocks is influenced not only by the δ44/40Ca of seawater but also by diagenetic processes and fractionation associated with carbonate precipitation. In this study, we investigate the dominant controls on carbonate δ44/40Ca in Upper Permian to Middle Triassic limestones (ca. 253 to 244 Ma) from south China and Turkey. This time interval is ideal for assessing controls on Ca isotope ratios in carbonate rocks because fluctuations in seawater δ44/40Ca may be expected based on several large carbon isotope (δ13C) excursions ranging from − 2 to + 8‰. Parallel negative δ13C and δ44/40Ca excursions were previously identified across the end-Permian extinction horizon. Here, we find a second negative excursion in δ44/40Ca of ~ 0.2‰ within Lower Triassic strata in both south China and Turkey; however, this excursion is not synchronous between regions and thus cannot be interpreted to reflect secular change in the δ44/40Ca of global seawater. Additionally, δ44/40Ca values from Turkey are consistently 0.3‰ lower than contemporaneous samples from south China, providing further support for local or regional influences. By measuring δ44/40Ca and Sr concentrations ([Sr]) in two stratigraphic sections located at opposite margins of the Paleo-Tethys Ocean, we can determine whether the data represent global conditions (e.g., secular variations in the δ44/40Ca of seawater) versus local controls (e.g., original mineralogy or diagenetic alteration). The [Sr] and δ44/40Ca data from this study are best described statistically by a log-linear correlation that also exists in many previously published datasets of various geological ages. Using a model of early marine diagenetic water-rock interaction, we illustrate that this general correlation can be explained by the chemical evolution of bulk carbonate sediment samples with different initial mineralogical compositions that subsequently underwent recrystallization. Although early diagenetic resetting and carbonate mineralogy strongly influence the carbonate δ44/40Ca values, the relationship between [Sr] and δ44/40Ca holds potential for reconstructing first-order secular changes in seawater δ44/40Ca composition.

The end-Triassic mass extinction coincided with a negative δ13C excursion, consistent with release of 13C-depleted CO2 from the Central Atlantic Magmatic Province. However, the amount of carbon released and its effects on ocean chemistry are poorly constrained. The coupled nature of the carbon and calcium cycles allows calcium isotopes to be used for constraining carbon cycle dynamics and vice versa. We present a high-resolution calcium isotope (δ44/40Ca) record from 100 m of marine limestone spanning the Triassic/Jurassic boundary in two stratigraphic sections from northern Italy. Immediately above the extinction horizon and the associated negative excursion in δ13C, δ44/40Ca decreases by ∼0.8‰ in 20 m of section and then recovers to preexcursion values. Coupled numerical models of the geological carbon and calcium cycles demonstrate that this δ44/40Ca excursion is too large to be explained by changes to seawater δ44/40Ca alone, regardless of CO2 injection volume and duration. Less than 20% of the δ44/40Ca excursion can be attributed to acidification. The remaining 80% likely reflects a higher proportion of aragonite in the original sediment, based largely on high concentrations of Sr in the samples. Our study demonstrates that coupled models of the carbon and calcium cycles have the potential to help distinguish contributions of primary seawater isotopic changes from local or diagenetic effects on the δ44/40Ca of carbonate sediments. Differentiating between these effects is critical for constraining the impact of ocean acidification during the end-Triassic mass extinction, as well as for interpreting other environmental events in the geologic past.

The net export of organic matter from the surface ocean and its respiration at depth create vertical gradients in nutrient and oxygen availability that play a primary role in structuring marine ecosystems. Changes in the properties of this 'biological pump' have been hypothesized to account for important shifts in marine ecosystem structure, including the Cambrian explosion. However, the influence of variation in the behavior of the biological pump on ocean biogeochemistry remains poorly quantified, preventing any detailed exploration of how changes in the biological pump over geological time may have shaped long-term shifts in ocean chemistry, biogeochemical cycling, and ecosystem structure. Here, we use a 3-dimensional Earth system model of intermediate complexity to quantitatively explore the effects of the biological pump on marine chemistry. We find that when respiration of sinking organic matter is efficient, due to slower sinking or higher respiration rates, anoxia tends to be more prevalent and to occur in shallower waters. Consequently, the Phanerozoic trend toward less bottom-water anoxia in continental shelf settings can potentially be explained by a change in the spatial dynamics of nutrient cycling rather than by any change in the ocean phosphate inventory. The model results further suggest that the Phanerozoic decline in the prevalence ocean anoxia is, in part, a consequence of the evolution of larger phytoplankton, many of which produce mineralized tests. We hypothesize that the Phanerozoic trend toward greater animal abundance and metabolic demand was driven more by increased oxygen concentrations in shelf environments than by greater food (nutrient) availability. In fact, a lower-than-modern ocean phosphate inventory in our closed system model is unable to account for the Paleozoic prevalence of bottom-water anoxia. Overall, these model simulations suggest that the changing spatial distribution of photosynthesis and respiration in the oceans has exerted a first-order control on Earth system evolution across Phanerozoic time.

Determining which biological traits affect taxonomic durations is critical for explaining macroevolutionary patterns. Two approaches are commonly used to investigate the associations between traits and durations and/or extinction and origination rates: analyses of taxonomic occurrence patterns in the fossil record and comparative phylogenetic analyses, predominantly of extant taxa. By capitalizing upon the empirical record of past extinctions, paleontological data avoid some of the limitations of existing methods for inferring extinction and origination rates from molecular phylogenies. However, most paleontological studies of extinction selectivity have ignored phylogenetic relationships because there is a dearth of phylogenetic hypotheses for diverse non-vertebrate higher taxa in the fossil record. This omission inflates the degrees of freedom in statistical analyses and leaves open the possibility that observed associations are indirect, reflecting shared evolutionary history rather than the direct influence of particular traits on durations. Here we investigate global patterns of extinction selectivity in Devonian terebratulide brachiopods and compare the results of taxonomic vs. phylogenetic approaches. Regression models that assume independence among taxa provide support for a positive association between geographic range size and genus duration but do not indicate an association between body size and genus duration. Brownian motion models of trait evolution identify significant similarities in body size, range size, and duration among closely related terebratulide genera. We use phylogenetic regression to account for shared evolutionary history and find support for a significant positive association between range size and duration among terebratulides that is also phylogenetically structured. The estimated range size - duration relationship is moderately weaker in the phylogenetic analysis due to the down-weighting of closely related genera that were both broadly distributed and long lived; however, this change in slope is not statistically significant. These results provide evidence for the phylogenetic conservatism of organismal and emergent traits, yet also the general phylogenetic independence of the relationship between range size and duration.

We sought to evaluate the prevalence rate and factors associated with post adoption depression. One hundred and twelve adoptive mothers of infants under 12 months of age were recruited from local and national adoption organizations. A modified Edinburgh Postnatal Depression Scale (EPDS) and a questionnaire collecting medical and psychiatric history, perceived stress, and demographics were administered retrospectively. The rates of significant depressive symptoms (defined as EPDS >or=12) were calculated at three time points post adoption, and associations with specific clinical variables (personal or family psychiatric history, stress, and adjustment difficulty) were assessed. Eighty-six mothers were included. Rates of significant depressive symptoms (EPDS >or=12) were found in 27.9% of subjects at 0-4 weeks, 25.6% at 5-12 weeks, and 12.8% at 13-52 weeks post adoption. Significant depressive symptoms were not associated with personal or family psychiatric history but were associated with stress (p = 0.0011) and adjustment difficulties (p = 0.042) post adoption. Significant depressive symptoms were relatively common in adoptive mothers within the first year after adoption and were associated with environmental stress. Prospective studies are needed to confirm the existence of post adoption depression and the factors associated with it. [ABSTRACT FROM AUTHOR]

The treatment of depression during pregnancy is both a common and complex clinical challenge. The decision to expose the fetus to antidepressant medication during pregnancy must be weighed against the risks of untreated maternal depression to both mother and fetus. Maternal depression during pregnancy has been associated with increased rates of preterm birth and maternal substance use. The safety of antidepressant use during pregnancy seems to be largely reassuring but there remain 2 areas of controversy including neonatal withdrawal syndrome and primary pulmonary hypertension of the newborn. Individualized treatment recommendations based on the patient's history are essential to optimize outcomes. [ABSTRACT FROM AUTHOR]

Neuroactive steroids including allopregnanolone are implicated in the pathophysiology of peripartum depressive symptoms (PDS). We performed a systematic review searching PubMed/Embase/PsychInfo/Cinhail through 08/2023 (updated in 07/2024), and conducted a random-effects meta-analysis of studies comparing allopregnanolone blood concentrations in women with versus without PDS at various timepoints during the 2 nd and 3 rd trimester and the postpartum period, calculating standardized mean differences (SMDs) and 95% confidence intervals (CIs). Meta-regression and subgroup analyses included age, diagnoses of affective disorders before pregnancy, antidepressant treatment, analytical methods, and sample type. Study quality was assessed using the Newcastle-Ottawa-scale. The study protocol was registered on PROSPERO (registration number CRD42022354495). We retrieved 13 studies with 2509 women (n = 849 with PDS). Allopregnanolone concentrations did not differ between women with versus without PDS at any timepoint (p > 0.05). Allopregnanolone concentrations assessed during pregnancy did not differ for women with versus without PDS at postpartum follow-up (p > 0.05). Subgroup analyses indicated higher allopregnanolone concentrations in women with versus without PDS at gestational weeks 21-24 and 25-28 (SMD = 1.07, 95% CI = 0.04, 2.11 and SMD = 0.92, 95% CI = 0.26, 1.59 respectively). Moreover, we reported differences between studies using mass-spectrometry combined with chromatography versus immunoassays at gestational weeks 25-28 (p = 0.01) and plasma versus serum samples at gestational weeks 21-24 (p = 0.005). Study quality was rated as poor, good, and fair for two, one and ten studies respectively. PDS were not associated with differences for allopregnanolone concentrations. The use of heterogenous peripartum time points, study cohorts, depression symptom measures and analytical methods has hampered progress in elucidating neuroactive steroid signaling linked to PDS., Competing Interests: Competing interests: KMD serves as a consultant to Sage Therapeutics, Brii Biosciences, Gerbera Therapeutics, GH Research, Neuroscience Software and Reunion Neuroscience. KMD served as a study principal investigator for contracted research awarded to the Feinstein Institutes for Medical Research from Sage Therapeutics, Woebot Health and Premier Healthcare. JLP receives research support from NIMH and Janssen Pharmaceuticals. JLP has two patents: “Epigenetic Biomarkers of Postpartum Depression” and “Epigenetic Biomarkers of Premenstrual Dysphoric Disorder and SSRI Response.” JLP has Founder’s Stock options in Dionysus Health. JLP has received consulting fees from SAGE Therapeutics, Biogen, Flo Health, Pure Tech, Brii Biosciences, and Merck. She receives royalties from UpToDate and Elsevier. She has produced content for and received honoraria from CMEToGo, Peerview Institute for Medical Education, Global Learning Collaborative, and Karuna Therapeutics. Georgios Schoretsanitis has served as a consultant for Dexcel Pharma, HLS Therapeutics and Thermo Fisher and has received speaker fees from HLS Therapeutics and Saladax. All other authors declare no conflicts of interest. Ethics: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. No informed consent was necessary for this type of research., (© 2024. The Author(s).)

Postpartum depression (PPD) affects ~10-15% of childbearing individuals, with deleterious consequences for two generations. Recent research has explored the biological mechanisms of PPD, particularly neuroactive steroids (NAS). We sought here to investigate associations between NAS levels and ratios during pregnancy and the subsequent development of depressive symptoms with postpartum onset. NAS levels and psychological scales were measured in individuals with and without mood disorders at up to eight visits across pregnancy and postpartum. Generalized linear mixed-effects regression models were used to assess relationships in euthymic pregnant individuals between each of the NAS biomarkers and ratios and subsequent PPD. Participants with a one-unit increase in the log isoallopregnanolone/pregnanolone ratio at the third trimester (T3) had higher odds (OR = 1.64, 95% CI: 1.13-2.37, FDR adjusted p = 0.038, C-index = 0.82), and those with a one-unit increase in the log pregnanolone/progesterone ratio at T3 had lower odds (OR = 0.64, 95% CI: 0.47-0.88, FDR adjusted p = 0.036, C-index = 0.82) of developing PPD; those with a one-unit increase in the log progesterone level at T3 had higher odds of developing PPD (OR = 4.00, 95% CI: 1.54-10.37, FDR adjusted p = 0.035, C-index = 0.80). We found key differences in the progesterone metabolic pathway at the third trimester, indicating likely decreased activity/expression of the 3α-HSD enzyme and/or increased activity/expression of 3β-HSD., Competing Interests: Competing interests: JLP holds the rights to two patents: “DNA Methylation Biomarkers of PPD Risk” and “Epigenetic Biomarkers Predictive of Premenstrual Dysphoric Disorder, Perimenopausal Depression and SSRI Response.” JLP owns founders’ stock in Dionysus Health. She has served as a consultant to the following companies: Biogen, SAGE Therapeutics, Merck, Brii Biologics, Pure Tech, Flo Health. JLP also receives research support from Janssen and Myriad. GP served as a paid consultant to PureTech Health (Boston, MA, USA), GABA Therapeutics, and NeuroTrauma Sciences (Alpharetta, GA, USA). He has two patent applications, one on N-palmitoylethanolamine (PEA) and peroxisome proliferator-activated receptor alpha (PPAR-α) agonists US20180369171A1 allowed on May 16, 2023, and one on allopregnanolone analogs US11266663B2 allowed on March 8, 2022, in the treatment of neuropsychiatric disorders. The other authors report no relevant financial interests., (© 2025. The Author(s), under exclusive licence to American College of Neuropsychopharmacology.)

Rationale: Premenstrual dysphoric disorder (PMDD) is characterized by severe affective symptoms during the luteal phase of the menstrual cycle. There is some evidence of altered interactions between the hypothalamic pituitary gonadal (HPG) and hypothalamic pituitary adrenal (HPA) axes in PMDD. There is also evidence that similar affective disorders such as major depression and perinatal depression are associated with dysregulation in immune factors, but this has not been characterized in PMDD., Aims: The goals of this exploratory study were to identify 1) whether HPA-HPG axis interactions and immune markers differ between PMDD patients and controls across the menstrual cycle; 2) how luteal phase sertraline treatment impacts stress and inflammatory markers., Methods: Participants were females age 18-50 with regular menstrual cycles, not using psychotropic or hormonal medications, and were assigned to a control group or PMDD group based on prospective daily symptom ratings and clinical interview. Blood was drawn in the follicular and luteal phases, during laboratory sessions involving a mildly stressful task. In a second luteal phase, PMDD participants received open-label sertraline (50 mg/d) from ovulation to menses. Serum cortisol and ACTH were measured via ELISA and operationalized as area under the curve with respect to ground (AUCg), and peak level following laboratory task. Serum TNF-α, IL-6, CXCL-8, and IL-1β were measured using multiplex kits. Serum allopregnanolone (ALLO) was measured by gas chromatography/mass spectroscopy. To characterize HPA-HPG axis interactions across the menstrual cycle in PMDD participants and controls, multilevel linear models predicted cortisol and ACTH from the interaction of cycle phase (controlling for sertraline treatment), ALLO, and group. To determine the effects of sertraline treatment on inflammatory markers and how groups might differ in cyclical change on each marker, multilevel linear models predicted inflammatory markers from cycle phase (controlling for sertraline treatment) and group. A final set of exploratory models tested whether inflammatory markers predict premenstrual symptom score severity., Results: The sample included n=77 participants (41 controls, 36 PMDD); 28 participants with PMDD completed sertraline treatment. Group x phase x ALLO interactions showed that higher ALLO levels predicted lower cortisol peak in the treated luteal phase (interaction between phase and ALLO, p=0.042), and there was a higher cortisol peak in the treated luteal phase than the untreated luteal phase (p=0.038). CXCL-8 was significantly associated with premenstrual symptom severity after controlling for group and cycle phase (p=0.011). There were no main effects of group, phase, or ALLO on cortisol AUCg, ACTH AUCg, IL-6, CXCL-8, IL-1β, nor TNF-α (p's>0.05)., Conclusion: Serum markers of HPA axis and immune function did not vary by menstrual cycle phase nor PMDD status. However, sertraline treatment in the luteal phase was associated with higher ALLO levels predicting lower cortisol peak in response to mild laboratory stress, suggesting that sertraline treatment may normalize HPG-HPA axis interactions among individuals with PMDD. Greater premenstrual symptomatology was associated with higher levels of the inflammatory marker CXCL-8, but further research is needed into the potential role of inflammation in PMDD., Competing Interests: Declaration of Competing Interest ALM holds a provisional patent on the anti-inflammatory effects of allopregnanolone and related neurosteroids, and has current and previous funding from Sage Therapeutics related to the anti-inflammatory actions of allopregnanolone. LH has consulted for PureTech Health and Flo Health. JLP has research funding from NIMH and Janssen Pharmaceuticals; served as a consultant to SAGE Therapeutics, Biogen, Merck, Brii Biologics, Pure Tech, Dionysus Health, and Flo Health; speaker for employees of Karuna Therapeutics; founder’s stock in Dionysus Health; two patents: “Epigenetic Biomarkers of Postpartum Depression” and “Epigenetic Biomarkers of PMDD and SSRI Response.” LMO reports no conflicts of interest, but has research funding from NIMH and NICHD and receives royalties and editorial fees from APA Publishing, Elsevier, and UpToDate., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Gastrointestinal (GI) symptoms such as bloating, constipation, and nausea are common in the days before menstruation, experienced by as many as 73 % of menstruating individuals. Mood may influence the link between menstrual cycle and GI symptoms, with prior studies indicating that even among healthy controls, GI symptoms worsen premenstrually and are associated with worsening mood. Associations between GI symptoms and mood are poorly understood among those with premenstrual syndrome (PMS), a cluster of mood and/or physical symptoms that occur in the week before menses affecting roughly 20 % of menstruators. Our primary aim was to examine associations between GI symptoms and mood symptoms across the menstrual cycle, in those who do and do not report PMS using a menstrual tracking app. We hypothesized that GI symptoms would be reported more frequently in the luteal phase than follicular phase, and that frequency of GI symptoms would be positively associated with mood symptoms in those with PMS. We analyzed data from 33,628 menstrual cycles across 32,241 participants, including n = 27,897 controls (29,137 menstrual cycles) and n = 4344 PMS participants (4491 menstrual cycles). GI symptoms were reported significantly more frequently in the luteal phase than the follicular phase in both control and PMS groups (p < 0.001). Mood symptoms were significantly positively associated with GI symptoms in both groups, in both follicular and luteal phases (p < 0.001). Results suggest that premenstrual GI symptoms are a common issue, and additional work is needed to explore associations between mood and GI symptoms in the context of the menstrual cycle., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Premenstrual Syndrome (PMS) and Premenstrual Dysphoric Disorder (PMDD), collectively known as Premenstrual Disorders (PMDs), cause significant distress and functional impairment, and premenstrual exacerbation (PME) affects a large proportion of women with psychiatric diagnoses. Childhood trauma is one factor that may contribute to PMD/PME risk. This study examines the relationship between childhood trauma and PMDs, PME, and non-PMD psychiatric illness., Methods: This study is a secondary analysis of data from a prospective cohort. Participants completed self-assessments on childhood trauma using the Childhood Traumatic Event Scale (CTE-S) and on premenstrual symptoms using the Premenstrual Symptoms Screening Tool (PSST). Psychiatric diagnoses were assessed through structured clinical interviews. Participants were divided into four groups based on their PSST scores and psychiatric illness status: (1) Premenstrual Disorders (PMDs; moderate to severe PMS and PMDD), (2) PME, (3) psychiatric controls (PC; individuals with psychiatric illness but no significant premenstrual symptoms), and (4) healthy controls (HC; individuals with no psychiatric illness and no significant premenstrual symptoms). Statistical analyses, including ANOVA, Tukey's HSD test, Fisher's exact test, and logistic regression, were conducted to examine differences among the groups., Results: Data from 391 participants were analyzed. Participants with PME and PC reported a higher quantity and severity of childhood traumatic events compared to HCs (p <.05). There was a weak but significant correlation between childhood trauma and premenstrual symptom burden across all groups (R = .18, p <.001). Within-group analysis revealed moderate correlations between childhood trauma and premenstrual symptoms driven by the PMD group (R = .42, p = .01)., Conclusions: The findings underscore the impact of childhood traumatic events on mental health and premenstrual symptoms and highlight the need for additional research to explore the underlying mechanisms linking childhood trauma to the continuum of premenstrual disorders, to improve the efficacy of trauma-focused interventions for affected individuals., Competing Interests: JP has research funding from NIMH, Janssen Pharmaceuticals and Myriad. She has served as a consultant to SAGE Therapeutics, Biogen, Merck, Brii Biologics, Pure Tech, Dionysus Health, and Flo Health. She has founders stock in Dionysus Health. She has two patents: “Epigenetic Biomarkers of Postpartum Depression” and “Epigenetic Biomarkers of PMDD and SSRI Response.” The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Standeven, Bajaj, McEvoy, Shirinian, Voegtline, Osborne, Payne and Hantsoo.)

Body size is a fundamental biological trait shaping ecological interactions, evolutionary processes, and our understanding of the structure and dynamics of marine communities on a global scale. Accurately defining a species' body size, despite the ease of measurement, poses significant challenges due to varied methodologies, tool usage, and subjectivity among researchers, resulting in multiple, often discrepant size estimates. These discrepancies, stemming from diverse measurement approaches and inherent variability, could substantially impact the reliability and precision of ecological and evolutionary studies reliant on body size data across extensive species datasets. This study examines the variation in reported maximum body sizes across 69,570 individual measurements of maximum size, ranging from <0.2 μm to >45 m, for 27,271 species of marine metazoans. The research aims to investigate how reported maximum size variations within species relate to organism size, taxonomy, habitat, and the presence of skeletal structures. The investigation particularly focuses on understanding why discrepancies in maximum size estimates arise and their potential implications for broader ecological and evolutionary studies relying on body size data. Variation in reported maximum sizes is zero for 38% of species, and low for most species, although it exceeds two orders of magnitude for some species. The likelihood of zero variation in maximum size decreased with more measurements and increased in larger species, though this varied across phyla and habitats. Pelagic organisms consistently had low maximum size range values, while small species with unspecified habitats had the highest variation. Variations in maximum size within a species were notably smaller than interspecific variation at higher taxonomic levels. Significant variation in maximum size estimates exists within marine species, and partially explained by organism size, taxonomic group, and habitat. Variation in maximum size could be reduced by standardized measurement protocols and improved meta-data. Despite the variation, egregious errors in published maximum size measurements are rare, and their impact on comparative macroecological and macroevolutionary research is likely minimal., Competing Interests: None Declared., (© 2024 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)

The standard genetic code defines the rules of translation for nearly every life form on Earth. It also determines the amino acid changes accessible via single-nucleotide mutations, thus influencing protein evolvability-the ability of mutation to bring forth adaptive variation in protein function. One of the most striking features of the standard genetic code is its robustness to mutation, yet it remains an open question whether such robustness facilitates or frustrates protein evolvability. To answer this question, we use data from massively parallel sequence-to-function assays to construct and analyze 6 empirical adaptive landscapes under hundreds of thousands of rewired genetic codes, including those of codon compression schemes relevant to protein engineering and synthetic biology. We find that robust genetic codes tend to enhance protein evolvability by rendering smooth adaptive landscapes with few peaks, which are readily accessible from throughout sequence space. However, the standard genetic code is rarely exceptional in this regard, because many alternative codes render smoother landscapes than the standard code. By constructing low-dimensional visualizations of these landscapes, which each comprise more than 16 million mRNA sequences, we show that such alternative codes radically alter the topological features of the network of high-fitness genotypes. Whereas the genetic codes that optimize evolvability depend to some extent on the detailed relationship between amino acid sequence and protein function, we also uncover general design principles for engineering nonstandard genetic codes for enhanced and diminished evolvability, which may facilitate directed protein evolution experiments and the bio-containment of synthetic organisms, respectively., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Rozhoňová et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Childhood and adolescent stress increase the risk of postpartum depression (PPD), often providing an increased probability of treatment refractoriness. Nevertheless, the mechanisms linking childhood/adolescent stress to PPD remain unclear. Our study investigated the longitudinal effects of adolescent stress on the hypothalamic-pituitary-adrenal (HPA) axis and postpartum behaviors in mice and humans. Adolescent social isolation prolonged glucocorticoid elevation, leading to long-lasting postpartum behavioral changes in female mice. These changes were unresponsive to current PPD treatments but improved with post-delivery glucocorticoid receptor antagonist treatment. Childhood/adolescent stress significantly impacted HPA axis dysregulation and PPD in human females. Repurposing glucocorticoid receptor antagonists for some cases of treatment-resistant PPD may be considered., Competing Interests: Competing Interests Statement The authors declare no competing interests.

The absence of non-invasive tests that can monitor the status of the brain is a major obstacle for psychiatric care. In order to address this need, we assessed the feasibility of using tissue-specific gene expression to determine the origin of extracellular vesicle (EV) mRNAs in peripheral blood. Using the placenta as a model, we discovered that 26 messenger RNAs that are specifically expressed in the placenta are present in EVs circulating in maternal blood. Twenty-three of these transcripts were either exclusively or highly expressed in maternal blood during pregnancy only and not in the postpartum period, verifying the feasibility of using tissue-specific gene expression to infer the tissue of origin for EV mRNAs. Using the same bioinformatic approach, which provides better specificity than isolating L1 cell-adhesion molecule containing EVs, we discovered that 181 mRNAs that are specifically expressed in the female brain are also present in EVs circulating in maternal blood. Gene set enrichment analysis revealed that these transcripts, which are involved in synaptic functions and myelination, are enriched for genes implicated in mood disorders, schizophrenia, and substance use disorders. The EV mRNA levels of 13 of these female brain-specific transcripts are associated with postpartum depression (adjusted p-vals = 3 × 10 -5 to 0.08), raising the possibility that they can be used to infer the state of the brain. In order to determine the extent to which EV mRNAs reflect transcription in the brain, we compared mRNAs isolated from cells and EVs in an iPSC-derived brain microphysiological system differentiated for 3 and 9 weeks. We discovered that, although cellular and extracellular mRNA levels are not identical, they do correlate, and it is possible to extrapolate cellular RNA expression changes in the brain via EV mRNA levels. Our findings bring EV mRNAs to the forefront of peripheral biomarker development efforts in psychiatric diseases by demonstrating the feasibility of inferring transcriptional changes in the brain via blood EV mRNA levels., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

This perspective reviews how atmospheric compositions, animals and marine algae evolved together to determine global ocean habitability during the past 500 million years., (© The Author(s) 2024. Published by Oxford University Press on behalf of China Science Publishing & Media Ltd.)

Rationale: Premenstrual dysphoric disorder (PMDD) affects approximately 5% of menstruating individuals, with significant negative mood symptoms in the luteal phase of the menstrual cycle. PMDD's pathophysiology and treatment mechanisms are poorly characterized, but may involve altered neuroactive steroid function in the brain. Selective serotonin reuptake inhibitors (SSRIs), a first-line PMDD treatment, reportedly alter gamma-aminobutyric acid (GABA)ergic neuroactive steroid levels in PMDD., Aims: The aims of this study were to determine whether the SSRI sertraline increased serum levels of neuroactive steroids that modulate the effect of GABA at GABA-A receptors (GABAAR) and if so, whether an increase was associated with improvement in PMDD symptoms., Methods: Participants included controls and individuals with PMDD. Serum levels of 9 neuroactive steroids were measured (3α,5α-THP; 3α5β-THP; pregnenolone; 3α,5α-androsterone; 3α,5β-androsterone; 3α,5α-A-diol; 3α5β-A-diol; 3α,5α-THDOC; 3α5β-THDOC) in the follicular and luteal phases. In the subsequent luteal phase, neuroactive steroids were measured during sertraline treatment (50 mg sertraline from approximate ovulation to menses onset) in the PMDD group. Mixed models assessed associations among diagnostic group, menstrual cycle phase, and sertraline treatment., Results: Participants included 38 controls and 32 women with PMDD. There were no significant differences in neuroactive steroid levels between controls and participants with PMDD in the luteal phase (p > 0.05). Within the PMDD group, sertraline treatment significantly increased serum pregnanolone levels and the pregnanolone:progesterone ratio, and decreased 3α,5α-androsterone., Conclusions: This was the first study to assess the impact of SSRI treatment on peripheral levels of GABAergic neuroactive steroids in PMDD. Within the PMDD group, sertraline treatment was associated with a significant increase in luteal phase serum pregnanolone levels and a significantly increased pregnanolone:progesterone ratio, a novel finding. Future research should examine alterations in the metabolic pathways among GABAergic neuroactive steroids in individuals with PMDD, in a placebo-controlled design., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: JLP: I have research funding from NIMH and Janssen Pharmaceuticals. I have served as a consultant to SAGE Therapeutics, Biogen, Merck, Brii Biologics, Pure Tech, Dionysus Health, and Flo Health. I have given a talk to the employees of Karuna Therapeutics. I have founders stock in Dionysus Health. I have two patents: “Epigenetic Biomarkers of Postpartum Depression” and “Epigenetic Biomarkers of PMDD and SSRI Response.”LH: Previously served as a consultant to Pure Tech Health, Flo Health. ALM: ALM holds a provisional patent on the anti-inflammatory effects of allopregnanolone and related neurosteroids, and has current and previous funding from Sage Therapeutics related to the anti-inflammatory actions of allopregnanolone., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

A novel binding layer (BL) as part of the diffusive gradients in thin films (DGT) technique was developed for the two-dimensional visualization and quantification of labile phosphorus (P) in soils. This BL was designed for P detection by synchrotron-based X-ray fluorescence microscopy (XFM). It differs from the conventional DGT BL as the hydrogel is eliminated to overcome the issue that the fluorescent X-rays of P are detected mainly from shallow sample depths. Instead, the novel design is based on a polyimide film (Kapton) onto which finely powdered titanium dioxide-based P binding agent (Metsorb) was applied, resulting in superficial P binding only. The BL was successfully used for quantitative visualization of P diffusion from three conventional P fertilizers applied to two soils. On a selection of samples, XFM analysis was confirmed by quantitative laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The XFM method detected significant differences in labile P concentrations and P diffusion zone radii with the P fertilizer incubation, which were explained by soil and fertilizer properties. This development paves the way for fast XFM analysis of P on large DGT BLs to investigate in situ diffusion of labile P from fertilizers and to visualize large-scale P cycling processes at high spatial resolution.

Academic psychiatry has slightly higher rates of women in the upper ranks and leadership positions than academic medicine as a whole but women continue to be seriously underrepresented. Psychiatry departments should take specific steps to address barriers for women in psychiatry including harassment and discrimination, Imposter Syndrome, lack of mentorship and sponsorship, work-life integration issues, and overinvolvement in nonpromotion generating activities. Addressing these barriers within academic psychiatry will improve the environment for all minorities., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2023 Elsevier Inc. All rights reserved.)

AbstractThe joint distribution of selection coefficients and mutation rates is a key determinant of the genetic architecture of molecular adaptation. Three different distributions are of immediate interest: (1) the "nominal" distribution of possible changes, prior to mutation or selection; (2) the "de novo" distribution of realized mutations; and (3) the "fixed" distribution of selectively established mutations. Here, we formally characterize the relationships between these joint distributions under the strong-selection/weak-mutation (SSWM) regime. The de novo distribution is enriched relative to the nominal distribution for the highest rate mutations, and the fixed distribution is further enriched for the most highly beneficial mutations. Whereas mutation rates and selection coefficients are often assumed to be uncorrelated, we show that even with no correlation in the nominal distribution, the resulting de novo and fixed distributions can have correlations with any combination of signs. Nonetheless, we suggest that natural systems with a finite number of beneficial mutations will frequently have the kind of nominal distribution that induces negative correlations in the fixed distribution. We apply our mathematical framework, along with population simulations, to explore joint distributions of selection coefficients and mutation rates from deep mutational scanning and cancer informatics. Finally, we consider the evolutionary implications of these joint distributions together with two additional joint distributions relevant to parallelism and the rate of adaptation.

Background: Anxiety disorders are the most common psychiatric disorder during the perinatal period and one of the major risk factors for postpartum depression, yet we know little about biological factors in the etiology of perinatal anxiety. A growing literature points to neuroactive steroid (NAS) dysregulation in perinatal mental illness, but directionality has not been clearly demonstrated, results are not consistent, and no studies have investigated NAS in a population with pure anxiety without comorbid depression. We aimed to add to the limited literature by examining the association between anxiety without comorbid depression and metabolic pathways of NAS longitudinally across the peripartum., Methods: We measured anxiety symptoms by psychological scales and NAS levels using Gas Chromatography-Mass Spectrometry (GC-MS) at the second and third trimester (T2 and T3) and week 6 postpartum (W6) in n = 36 women with anxiety and n = 38 healthy controls. The anxiety group was determined by a data-driven approach, and cross-sectional and longitudinal statistical methods were used to examine the relationship between the study population and NAS., Results: We found that anxiety had a significant moderating effect on the relationship between progesterone and allopregnanolone, with no such effect for the relationships between progesterone and the intermediate (5α-DHP) or isomeric (isoallopregnanolone) compounds in this pathway, and no effects on the corresponding pathway converting progesterone to pregnanolone and epipregnanolone. We also found a less precipitous decline in the ratio of allopregnanolone to progesterone between T3 and W6 in the anxiety group compared to the non-anxiety group. A genotype analysis of a single-nucleotide polymorphism in the AKR1C2 gene demonstrated that the relationship of allopregnanolone to the intermediate metabolite, 5α-DHP, differed by genotype., Conclusion: Our exploratory findings indicate that, for pregnant people with anxiety, metabolism is shunted more aggressively toward the endpoint of the progesterone to allopregnanolone metabolic pathway than it is for those without anxiety., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr. Payne has served as a consultant for SAGE Therapeutics, Biogen, Brii Biologics, and Pure Tech. Dr. Payne also holds a patent entitled “Epigenetic Biomarkers of Postpartum Depression.” Dr. Pinna is a paid consultant to PureTech Health (Boston, MA, USA), GABA Therapeutics, and NeuroTrauma Sciences (Alpharetta, GA, USA). He has two patent applications, one on N-palmitoylethanolamine (PEA) and peroxisome proliferator-activated receptor alpha (PPAR-α) agonists US20180369171A1, pending, and one on allopregnanolone analogs US11266663B2 granted on March 8, 2022, in the treatment of neuropsychiatric disorders. The other authors declare no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Two of the traits most often observed to correlate with extinction risk in marine animals are geographical range and body size. However, the relative effects of these two traits on extinction risk have not been investigated systematically for either background times or during mass extinctions. To close this knowledge gap, we measure and compare extinction selectivity of geographical range and body size of genera within five classes of benthic marine animals across the Phanerozoic using capture-mark-recapture models. During background intervals, narrow geographical range is strongly associated with greater extinction probability, whereas smaller body size is more weakly associated with greater extinction probability. During mass extinctions, the association between geographical range and extinction probability is reduced in every class and fully eliminated in some, whereas the association between body size and extinction probability varies in strength and direction across classes. While geographical range is universally the stronger predictor of survival during background intervals, variation among classes during mass extinction suggests a fundamental shift in extinction processes during these global catastrophes., Competing Interests: We declare we have no competing interests., (© 2023 The Authors.)

Perinatal depression is a common psychiatric condition that has negative effects on pregnancy and infant outcomes. Screening for the condition is relatively easy and should be done routinely in all medical care of the pregnant and postpartum woman and her infant. The risk-benefit analysis favors the use of antidepressant medications during pregnancy and lactation compared with the risk of untreated maternal depression. Other, nonpharmacological treatments will be discussed as well as new treatments, including a new class of medications that act on the inhibitory GABAergic neurotransmitter system., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The notion that mutations are random relative to their fitness effects is central to the Neo-Darwinian view of evolution. However, a recent interpretation of the patterns of mutation accumulation in the genome of Arabidopsis thaliana has challenged this notion, arguing for the presence of a targeted DNA repair mechanism that causes a nonrandom association of mutation rates and fitness effects. Specifically, this mechanism was suggested to cause a reduction in the rates of mutations on essential genes, thus lowering the rates of deleterious mutations. Central to this argument were attempts to rule out selection at the population level. Here, we offer an alternative and parsimonious interpretation of the patterns of mutation accumulation previously attributed to mutation bias, showing how they can instead or additionally be caused by developmental selection, that is selection occurring at the cellular level during the development of a multicellular organism. Thus, the depletion of deleterious mutations in A. thaliana may indeed be the result of a selective process, rather than a bias in mutation. More broadly, our work highlights the importance of considering development in the interpretation of population-genetic analyses of multicellular organisms, and it emphasizes that efforts to identify mechanisms involved in mutational biases should explicitly account for developmental selection., (© The Author(s) 2023. Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution.)

Premenstrual dysphoric disorder (PMDD) is a severe mood disorder, with affective symptoms that rise and fall in concert with the hormonal fluctuations of the menstrual cycle. PMDD's pathophysiology is poorly understood. This review describes recent research on potential biological contributors to PMDD, with a focus on neuroactive steroids, genetics, neuroimaging and cellular studies. Studies suggest that a key contributor is abnormal central nervous system (CNS) response to fluctuations in neuroactive steroid hormones. Imaging studies are limited but support alterations in serotonergic and GABA transmission. Genetic studies suggest heritability, yet specific genetic contributors have not been characterized. Finally, recent cutting-edge cellular studies indicate an underlying vulnerability to the effect of sex hormones at a cellular level. Overall the findings across studies do not yet fit together into a complete description of the underlying biology of PMDD. It is possible that PMDD consists of biological subtypes, and future research may benefit from a subtyping approach., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Mutations to gene regulatory networks can be maladaptive or a source of evolutionary novelty. Epistasis confounds our understanding of how mutations affect the expression patterns of gene regulatory networks, a challenge exacerbated by the dependence of epistasis on the environment. We used the toolkit of synthetic biology to systematically assay the effects of pairwise and triplet combinations of mutant genotypes on the expression pattern of a gene regulatory network expressed in Escherichia coli that interprets an inducer gradient across a spatial domain. We uncovered a preponderance of epistasis that can switch in magnitude and sign across the inducer gradient to produce a greater diversity of expression pattern phenotypes than would be possible in the absence of such environment-dependent epistasis. We discuss our findings in the context of the evolution of hybrid incompatibilities and evolutionary novelties.