Mass spectrometry-based metabolomics for the elucidation of alkaloid biosynthesis and function in invasive Vincetoxicum rossicum populations.

The genus Vincetoxicum includes a couple of highly invasive vines in North America that threaten biodiversity and challenge land management strategies. Vincetoxicum species are known to produce bioactive phenanthroindolizidine alkaloids that might play a role in the invasiveness of these plants via chemical interactions with other organisms. Untargeted, high-resolution mass spectrometry-based metabolomics approaches were used to explore specialized metabolism in Vincetoxicum plants collected from invaded sites in Ontario, Canada. All metabolites corresponding to alkaloids in lab and field samples of V. rossicum and V. nigrum were identified, which collectively contained 25 different alkaloidal features. The biosynthesis of these alkaloids was investigated by the incorporation of the stable isotope-labelled phenylalanine precursor providing a basis for an updated biosynthetic pathway accounting for the rapid generation of chemical diversity in invasive Vincetoxicum. Aqueous extracts of aerial Vincetoxicum rossicum foliage had phytotoxic activity against seedlings of several species, resulting in identification of tylophorine as a phytotoxin; tylophorine and 14 other alkaloids from Vincetoxicum accumulated in soils associated with full-sun and a high-density of V. rossicum. Using desorption-electrospray ionization mass spectrometry, 15 alkaloids were found to accumulate at wounded sites of V. rossicum leaves, a chemical cocktail that would be encountered by feeding herbivores. Understanding the specialized metabolism of V. rossicum provides insight into the roles and influences of phenanthroindolizidine alkaloids in ecological systems and enables potential, natural product-based approaches for the control of invasive Vincetoxicum and other weedy species.

Rapid entry to phenanthroindolizidine alkaloids via an acid-catalysed acyliminium ion-electrocyclization cascade.

A rapid total synthesis of seco-phenanthroindolizidine alkaloids was achieved involving a one-pot acid catalyzed deprotection- condensation-electrocyclization strategy. This synthetic route provided a concise synthesis of (±)-seco-antofine and (±)-septicine in only 4 steps with an overall yield of 22% and 17%, respectively.

Are changes in marital satisfaction sustained and steady, or sporadic and dramatic?

Although prominent theories of intimate relationships, and couples themselves, often conceive of relationships as fluctuating widely in their degree of closeness, longitudinal studies generally describe partners' satisfaction as stable and continuous or as steadily declining over time. The increasing use of group-based trajectory models (GBTMs) to identify distinct classes of change has reinforced this characterization, but these models fail to account for individual differences within classes and within-person variability across classes and may thus misrepresent how couples' satisfaction changes. The goal of the current analyses was to determine whether accounting for these additional sources of variance through growth mixture models (GMMs) alters characterizations of satisfaction changes over time. Applied to longitudinal data from 12 independent studies of first-married couples (combined N = 1,249 couples), GMMs that allowed for class-specific individual differences and within-person variability fit the data better than the GBTMs that constrained these to be equal across classes. Most notably, considerable within-person variability was evident within each class, consistent with the idea that spouses do indeed fluctuate in their satisfaction. Spouses who dissolved their marriages were 3.8-5.7 times more likely to be in classes characterized by greater volatility in satisfaction. Because the early years of marriage appear to be characterized by within-person fluctuations in satisfaction, time-varying correlates of these fluctuations are likely to be at least as important as time-invariant correlates in explaining why some marriages thrive where others falter. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Pursuing safety in social connection regulates the risk-regulation, social-safety, and behavioral-immune systems.

A new goal-systems model is proposed to help explain when individuals will protect themselves against the risks inherent to social connection. This model assumes that people satisfy the goal to feel included in safe social connections-connections where they are valued and protected rather than at risk of being harmed-by devaluing rejecting friends, trusting in expectancy-consistent relationships, and avoiding infectious strangers. In the hypothesized goal system, frustrating the fundamental goal to feel safe in social connection sensitizes regulatory systems that afford safety from the risk of being interpersonally rejected (i.e., the risk-regulation system), existentially uncertain (i.e., the social-safety system), or physically infected (i.e., the behavioral-immune system). Conversely, fulfilling the fundamental goal to feel safe in social connection desensitizes these self-protective systems. A 3-week experimental daily diary study (N = 555) tested the model hypotheses. We intervened to fulfill the goal to feel safe in social connection by repeatedly conditioning experimental participants to associate their romantic partners with highly positive, approachable words and images. We then tracked how vigilantly experimental versus control participants protected themselves when they encountered social rejection, unexpected behavior, or contagious illness in everyday life. Multilevel analyses revealed that the intervention lessoned self-protective defenses against each of these risks for participants who ordinarily felt most vulnerable to them. The findings provide the first evidence that the fundamental goal to feel safe in social connection can co-opt the risk-regulation, social-safety, and behavioral-immune systems as independent means for its pursuit. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Leveraging impression management motives to increase the use of face masks.

Three pilot studies (Ntotal = 832) revealed that people held more positive attitudes toward targets wearing protective face masks. Therefore, we examined whether knowledge of this self-presentational benefit would increase people's intentions to wear face masks. Participants (N = 997) were randomly assigned to read a passage about the COVID-19 pandemic, the safety benefit of mask-wearing, the self-presentational benefit of mask-wearing, or a combination of the latter two. Although this manipulation failed, findings revealed that preexisting beliefs about masked targets being more likable were positively associated with mask-wearing intentions, particularly among participants less concerned with disease or more politically conservative.

Identification of haemanthamine as a phytotoxic alkaloid in Narcissus pseudonarcissus L. (Daffodil) emerging buds.

Emerging buds of Narcissus pseudonarcissus were found to accumulate the alkaloid haemanthamine (1) at high concentrations, exceeding that of narciclasine (2), the most abundant constituent in bulbs of the plant. A phytoactivity screening assay demonstrated the novel phytotoxicity of haemanthamine against Raphanus sativus (radish), Lactuca sativus (lettuce), Triticum aestivum (red wheat), Solanum lycopersicum (tomato), Cucumis sativus (cucumber), Ipomoea (Morning glory), and Lens culinaris (lentil). Haemanthamine (1) phytotoxicity was found to exceed that of the commercial herbicide glyphosate and less toxic than narciclasine (2).

Truncated ring-A amaryllidaceae alkaloid modulates the host cell integrated stress response, exhibiting antiviral activity to HSV-1 and SARSCoV-2.

The total synthesis of four novel mono-methoxy and hydroxyl substituted ring-A dihydronarciclasine derivatives enabled identification of the 7-hydroxyl derivative as a potent and selective antiviral agent targeting SARSCoV-2 and HSV-1. The concentration of this small molecule that inhibited HSV-1 infection by 50% (IC50), determined by using induced pluripotent stem cells (iPCS)-derived brain organ organoids generated from two iPCS lines, was estimated to be 0.504 µM and 0.209 µM. No significant reduction in organoid viability was observed at concentrations up to 50 mM. Genomic expression analyses revealed a significant effect on host-cell innate immunity, revealing activation of the integrated stress response via PERK kinase upregulation, phosphorylation of eukaryotic initiation factor 2α (eIF2α) and type I IFN, as factors potentiating multiple host-defense mechanisms against viral infection. Following infection of mouse eyes with HSV-1, treatment with the compound dramatically reduced HSV-1 shedding in vivo.

Eyes Fixed on Heaven's Gate: An Empirical Examination of Blink Rate and Suicide.

Anecdotal and theoretical work suggests blink rate as an indicator of imminent suicide risk. We sought to empirically examine whether suicide decedents displayed a reduced blink rate in goodbye videos filmed before death, compared to several control groups. Independent raters coded blink rates from videos of 34 suicide decedents and four comparison groups: "mundane" product review, non-suicidal arousal, non-suicidal depression, and non-imminent risk of suicidal ideation. Mean blink rate was lower in the suicide decedent group relative to all comparison groups (ps < .001), except the depressed (p = .976) and suicidal ideation (p = .393) groups. Findings indicate blink rate may be reduced among individuals at imminent risk for suicide, exhibiting clinically-significant depressive symptoms, or experiencing suicidal ideation.

Leveraging smartphones to observe couples remotely and illuminate how COVID-19 stress shaped marital communication.

The height of the COVID-19 pandemic was an exceptionally stressful time for families that offered a unique opportunity to understand how stressful experiences occurring outside the relationship shape behavior occurring inside the relationship. Given the social distancing requirements of the pandemic, however, most research addressing this issue has relied on self-reports of behavior, which are susceptible to bias. In the summer of 2020, we asked a sample of married individuals living in the United States, Canada, Ireland, and the United Kingdom to complete online questionnaires assessing neuroticism and attachment insecurity, their levels of chronic stress, and their levels of acute stress due to the COVID-19 pandemic. We then asked participants to submit a 10-min video of themselves and their spouse attempting to solve an important marital problem that they recorded on their smartphone or other device and uploaded to a secure server. Coders were able to reliably code the behavior of both partners using an established coding system, and the distribution of codes was similar to prior research. Consistent with predictions, participants' COVID-19 stress interacted with their neuroticism and attachment avoidance to predict their levels of oppositional behavior, controlling for their levels of chronic stress and their partner's behavior; neuroticism and attachment avoidance were associated with behaving in a more oppositional manner among participants who reported high but not low COVID-19 stress. Attachment anxiety trended toward predicting more oppositional behavior regardless of stress. These results shed light on how stress affects behavior and introduce a novel way to observe family behavior remotely. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Evidence of a Bidirectional Association Between Daily Sexual and Relationship Satisfaction That Is Moderated by Daily Stress.

Prior research provides mixed evidence regarding the direction of the association between sexual and marital satisfaction. Whereas some studies suggest a bidirectional association, other studies fail to document one direction or the other. The current investigation used a 12-day diary study of 287 married individuals to clarify the nature of this association. Results from time-lagged mixed modeling revealed a significant positive bidirectional association. Both higher global sexual satisfaction one day and satisfaction with sex that occurred that day predicted higher marital satisfaction the next day; likewise, higher marital satisfaction one day significantly predicted higher global sexual satisfaction the next day and higher satisfaction with sex that occurred the next day. Both associations remained significant after controlling for participant's gender/sex, neuroticism, attachment insecurity, self-esteem, stress, perceived childhood unpredictability and harshness, age of first intercourse, construal level, age, and length of marriage. We also explored whether these covariates moderated either direction of the association. Daily stress was the most reliable moderator, with three of the four interactions tested remaining significant after Bonferroni corrections. The bidirectional association between global sexual and marital satisfaction and the positive association between satisfaction with sex that occurred that day and marital satisfaction the next day were significantly stronger when individuals experienced high versus low stress. Although the exploratory nature of all moderation analyses suggests they should be replicated before drawing strong conclusions, these findings highlight the importance of sexual satisfaction to marital satisfaction and vice versa and point to the power of stress in strengthening these associations.

An empirical investigation of the roles of biological, relational, cognitive, and emotional factors in explaining sex differences in dyadic sexual desire.

One challenge many marital couples face is that they experience discrepant levels of sexual desire for one another. Such discrepancies are particularly likely to arise in mixed-sex relationships because, at least in long-term relationships, men tend to have higher levels of sexual desire for their partner than do women. But what underlies this sex difference? We used a dyadic study of 100 mixed-sex community-based newlywed spouses to investigate the role of biological, relational, cognitive, and emotional factors in explaining sex differences in dyadic sexual desire for a long-term partner. Consistent with predictions, wives on average reported lower daily sexual desire for their spouse than did husbands. Moreover, individual differences in men's and women's levels of circulating testosterone explained this sex difference whereas relational (marital satisfaction, commitment), cognitive (sex-role identification, stress, self-esteem), and emotional (mood, depressive symptoms) factors did not. These findings advance our knowledge of factors that influence dyadic sexual desire and may have practical implications for treating relationship distress in mixed-sex marriages.

A flavin-dependent monooxygenase produces nitrogenous tomato aroma volatiles using cysteine as a nitrogen source.

Tomato (Solanum lycopersicum) produces a wide range of volatile chemicals during fruit ripening, generating a distinct aroma and contributing to the overall flavor. Among these volatiles are several aromatic and aliphatic nitrogen-containing compounds for which the biosynthetic pathways are not known. While nitrogenous volatiles are abundant in tomato fruit, their content in fruits of the closely related species of the tomato clade is highly variable. For example, the green-fruited species Solanum pennellii are nearly devoid, while the red-fruited species S. lycopersicum and Solanum pimpinellifolium accumulate high amounts. Using an introgression population derived from S. pennellii, we identified a locus essential for the production of all the detectable nitrogenous volatiles in tomato fruit. Silencing of the underlying gene (SlTNH1;Solyc12g013690) in transgenic plants abolished production of aliphatic and aromatic nitrogenous volatiles in ripe fruit, and metabolomic analysis of these fruit revealed the accumulation of 2-isobutyl-tetrahydrothiazolidine-4-carboxylic acid, a known conjugate of cysteine and 3-methylbutanal. Biosynthetic incorporation of stable isotope-labeled precursors into 2-isobutylthiazole and 2-phenylacetonitrile confirmed that cysteine provides the nitrogen atom for all nitrogenous volatiles in tomato fruit. Nicotiana benthamiana plants expressing SlTNH1 readily transformed synthetic 2-substituted tetrahydrothiazolidine-4-carboxylic acid substrates into a mixture of the corresponding 2-substituted oxime, nitro, and nitrile volatiles. Distinct from other known flavin-dependent monooxygenase enzymes in plants, this tetrahydrothiazolidine-4-carboxylic acid N-hydroxylase catalyzes sequential hydroxylations. Elucidation of this pathway is a major step forward in understanding and ultimately improving tomato flavor quality.

Automatic and controlled antecedents of suicidal ideation and action: A dual-process conceptualization of suicidality.

Dual-process models of cognition distinguish relatively automatic from relatively controlled processes in terms of their interactive impact on perception, judgment, and behavior. Such models have advanced explanation and prediction in a variety of domains across psychology but have yet to be comprehensively applied to the pressing societal and public health problem of suicide. We propose a model of suicide that integrates dual-process models of social cognition with ideation-to-action conceptualizations of suicide. The model specifies: (a) suicide-relevant automatic associations involving the self, others, the future, death, and bodily harm, (b) suicide-relevant motives involving the self, interpersonal relations, the future, and the desire to die, and (c) hypotheses regarding the conditions under which automatic associations and motives individually and interactively impact suicidal ideation and lethal action at various stages of an ideation-to-action framework. The model recasts a number of suicide-relevant variables in terms of the opportunity factor of dual-process theories of attitudes, which encompasses capacity-relevant variables (e.g., time, cognitive resources) that determine whether suicide-relevant judgments and behavior are the result of relatively automatic associations or more controlled, deliberative cognition. Accordingly, the model articulates a number of novel predictions regarding the sources of suicide-relevant automatic associations, motives, and opportunity factors, as well as their interactive influences on suicidal ideation and action. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Perceptions of Infectability to Disease Moderate the Association between Daily Concerns about Contracting COVID-19 and Satisfaction with Sex.

The behavioral immune system is an evolved adaptation comprised of automatic behavioral, cognitive, and affective reactions that has allowed humans throughout evolutionary history to avoid situations that risk infection by pathogens (e.g., physical proximity to sick people). Although behavioral immune system activation may be functional by helping people avoid such situations, experiencing these automatic reactions during sexual interactions may undermine people's evaluations of those interactions because sex requires close physical contact. We examined whether two sources of behavioral immune system activation (daily concern over contracting COVID-19 and individual differences in infection concern) undermined satisfaction with sex among 318 partnered adults in the U.S. during the COVID-19 pandemic. Participants reported individual differences in perceived infectability and then, every night for two weeks, reported their (a) daily concern about contracting COVID-19, (b) daily stress, (c) whether they had sex with their partner, and (d) their satisfaction with sex when it occurred. People's perceived infectability moderated the association between their daily concern about contracting COVID-19 and the extent to which they enjoyed sex when it occurred, such that people higher, but not lower, in perceived infectability enjoyed sex less on days that they were more worried about contracting COVID-19 than usual. This effect was not moderated by biological sex and remained significant when controlling for biological sex, age, relationship length, and frequency of sex. Results highlight the importance of the behavioral immune system to sexual functioning and suggest a novel avenue through which the COVID-19 pandemic has disrupted relationships.

Neural mechanisms of intimate partner aggression.

People sometimes hurt those they profess to love; yet our understanding of intimate partner aggression (IPA) and its causes remains incomplete. We examined brain activity using functional magnetic resonance imaging (fMRI) in an ethnically and racially diverse sample of 50 female-male, monogamous romantic couples as they completed an aggression task against their intimate partner, a close friend, and a different-sex stranger. Laboratory and real-world IPA were uniquely associated with altered activity within and connectivity between cortical midline structures that subserve social cognition and the computation of value. Men's IPA most corresponded to lower posterior cingulate reactivity during provocation and women's IPA most corresponded to lower ventromedial prefrontal cortex activity during IPA itself. Actor-partner independence modeling suggested women's IPA may correspond to their male partner's neural reactivity to provocation. Broadly, these findings highlight the importance of self-regulatory functions of the medial cortex and away from effortful inhibition subserved by dorsolateral cortices.

But What's Your Partner Up to? Associations Between Relationship Quality and Pornography Use Depend on Contextual Patterns of Use Within the Couple.

It is commonly assumed that exposure to pornography harms relationships because pornography changes the way that individuals think, feel, and behave in problematic ways. In the current research, we contribute to a small but growing body of work that challenges this assumption by carefully scrutinizing the relational context of pornography use. In contrast to dominant theoretical explanations in this field, we argue that at least some of the apparent negative "impacts" of pornography use on relationship quality may reflect partner dissimilarity in pornography use behavior rather than the consequences of exposure to such materials. Moreover, we further examine a particular type of pornography use - shared use with a partner - which previous evidence suggests may be positively associated with relationship quality. To this end, we sought to test whether dyadic patterns of pornography use, and related attributes, were associated with sexual and relationship satisfaction in two cross-sectional (N 1 = 200; N 3 = 207) and two longitudinal (N 2 = 77; N 4 = 277) samples of heterosexual couples. Across these samples, we found consistent evidence that partners who watch pornography together report higher relationship and sexual satisfaction than partners who do not, and notably, this association was not moderated by gender. Independent of this association, we also found evidence of a similarity-dissimilarity effect, such that the solitary pornography use of one partner was negatively associated with their own relationship and sexual satisfaction, but only in cases where their romantic partners used little or no pornography alone. Further consideration of several correlates of pornography use established comparable patterns of results for dissimilarity in attitudes toward pornography, erotophobia-erotophilia, sexual preferences, and sex drive. Importantly, only dissimilarity in sex drive statistically accounted for dissimilarity in solitary pornography use, suggesting that differences in sex drive may be implicated in the associations between pornography use and relationship quality. These findings demonstrate that links between pornography use and relationship health are partially a function of different dyadic patterns of pornography use within couples and do not always suggest relational harm.

How both partners' individual differences, stress, and behavior predict change in relationship satisfaction: Extending the VSA model.

We pooled data from 10 longitudinal studies of 1,104 married couples to test the Vulnerability-Stress-Adaptation (VSA) model of change in relationship satisfaction. Studies contained both spouses' self-reports of neuroticism, attachment anxiety, and attachment avoidance; observational measures of engagement and opposition during problem-solving discussions at baseline; and repeated reports of both spouses' stress and marital satisfaction over several years. Consistent with the VSA model, all three individual and partner qualities predicted changes in marital satisfaction that were mediated by observations of behavior and moderated by both partners' experiences with stress. In contrast to the VSA model, however, rather than accentuating the association between individual differences and behavior, both partners' stress moderated the strength, and even direction, of the association between behavior and changes in marital satisfaction over time. Taken together, these findings indicate that 1) qualities of both couple members shape their behavioral exchanges, 2) these behaviors explain how individuals and their partners' enduring qualities predict relationship satisfaction, and 3) stress experienced by both couple members strongly determines how enduring qualities and behavior predict changes in relationship satisfaction over time. The complex interplay among both partners' enduring qualities, stress, and behavior helps explain why studies may fail to document direct main effects of own and partner enduring qualities and behavior on changes in relationship satisfaction over time.

Metabolite profiling reveals a role for intercellular dihydrocamalexic acid in the response of mature Arabidopsis thaliana to Pseudomonas syringae.

The leaf intercellular space is a site of plant-microbe interactions where pathogenic bacteria such as Pseudomonas syringae grow. In Arabidopsis thaliana, the biosynthesis of tryptophan-derived indolic metabolites is induced by P. syringae infection. Using high-resolution mass spectrometry-based profiling and biosynthetic mutants, we investigated the role of indolic compounds and other small molecules in the response of mature Arabidopsis to P. syringae. We observed dihydrocamalexic acid (DHCA), the precursor to the defense-related compound camalexin, accumulating in intercellular washing fluids (IWFs) without further conversion to camalexin. The indolic biosynthesis mutant cyp71a12/cyp71a13 was more susceptible to P. syringae compared to mature wild-type plants displaying age-related resistance (ARR). DHCA and structural analogs inhibit P. syringae growth (MIC ~ 500 µg/mL), but not at concentrations found in IWFs, and DHCA did not inhibit biofilm formation in vitro. However, infiltration of exogenous DHCA enhanced resistance in mature cyp71a12/cyp71a13. These results provide evidence that DHCA derived from CYP71A12 and CYP71A13 activity accumulates in the intercellular space and contributes to the resistance of mature Arabidopsis to P. syringae without directly inhibiting bacterial growth.

CD38 is associated with bonding-relevant cognitions and relationship satisfaction over the first 3 years of marriage.

Although there are numerous benefits to having a satisfying romantic relationship, maintaining high levels of relationship satisfaction is difficult. Many couples experience declines in relationship satisfaction in the early years of marriage, and such declines predict not only relationship dissolution but also poor mental and physical health. Several recent studies indicate that genetic variation on the CD38 gene (CD38), at the single nucleotide polymorphism (SNP) rs3796863, is associated with cognitions and behaviors related to pair bonding; we thus leveraged longitudinal data from a sample of newlywed couples (N = 139 genotyped individuals; 71 couples) to examine whether rs3796863 is associated with relationship maintenance processes and, in turn, relationship satisfaction in the early years of marriage. Replicating and extending prior research, we found that individuals with the CC genotype (vs. AC/AA) of rs3796863 reported higher levels of gratitude, trust, and forgiveness and that trust mediated the association between rs3796863 and marital satisfaction. Moreover, the benefits conferred to CC individuals lasted over the first 3 years of marriage. To our knowledge, this is the first study to examine the link between variation in CD38 rs3796863 and marital functioning over time.

Do people realize how their partners make them feel? Relationship enhancement motives and stress determine the link between implicitly assessed partner attitudes and relationship satisfaction.

Do people realize the evaluative feelings that are spontaneously activated by their partner? If so, do they use those evaluations when judging their romantic relationships? To answer these questions, we investigated the association between automatic partner attitudes and judgments of relationship satisfaction in 7 studies. Study 1 was a meta-analysis of 86 correlations that revealed a very weak association between implicitly and explicitly assessed relationship evaluations, and Studies 2a-2c revealed that people failed to accurately report their automatic partner attitudes even when specifically asked to do so. Consistent with the idea that such inaccuracy emerged in part because motivational factors led people to override their automatic attitudes, Studies 3 and 4 demonstrated that automatic partner attitudes better aligned with relationship judgments when people were incentivized with money (Study 3) and had dissolved their relationship (Study 4). Nevertheless, consistent with the idea that overriding automatic attitudes requires the opportunity to deliberate, Studies 4 and 5 demonstrated that automatic partner attitudes better aligned with relationship judgments when people experienced more stress at the daily level (Study 4) and yearly for two years (Study 5). In Study 5, the interaction between stress and automatic attitudes emerged controlling indicators of negativity and was further moderated by relationship enhancing motivations among wives. These studies (a) help explain why automatic partner attitudes predict self-reported relationship satisfaction over time and (b) provide support for theories of social cognition suggesting that people have access to implicitly assessed attitudes that is obscured by motivations and opportunities to deliberate. (PsycInfo Database Record (c) 2021 APA, all rights reserved).