Three different macromolecular structures of poly(ethylene oxide-b-propylene oxide) copolymers, used in formulations of commercial demulsifiers for breaking water-in-crude oil emulsions, were investigated. The interfacial activity (), the lower interfacial tension (m), the critical micelle concentration (CMC), the interfacial concentration (Γ) and the molecular area (A) adsorbed at the interface of the surfactant solutions were evaluated. These results were correlated to surfactant performance in coalescing three different asphaltene model emulsions. The PEO-b-PPO commercial demulsifiers, that were capable to dewater asphaltene model emulsions, exhibited interfacial activity to the oil-water interface, reduced the interfacial tension to low values, reached the CMC at low concentration and presented low molecular area adsorbed at the interface.

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Background: Long-term studies of community and population dynamics indicate that abrupt disturbances often catalyse changes in vegetation and carbon stocks. These disturbances include the opening of clearings, rainfall seasonality, and drought, as well as fire and direct human disturbance. Such events may be superimposed on longerterm trends in disturbance, such as those associated with climate change (heating, drying), as well as resources. Intact neotropical forests have recently experienced increased drought frequency and fire occurrence, on top of pervasive increases in atmospheric CO 2 concentrations, but we lack long-term records of responses to such changes especially in the critical transitional areas at the interface of forest and savanna biomes. Here, we present results from 20 years monitoring a valley forest (moist tropical forest outlier) in central Brazil. The forest has experienced multiple drought events and includes plots which have and which have not experienced fire. We focus on how forest structure (stem density and aboveground biomass carbon) and dynamics (stem and biomass mortality and recruitment) have responded to these disturbance regimes. Results: Overall, the biomass carbon stock increased due to the growth of the trees already present in the forest, without any increase in the overall number of tree stems. Over time, both recruitment and especially mortality of trees tended to increase, and periods of prolonged drought in particular resulted in increased mortality rates of larger trees. This increased mortality was in turn responsible for a decline in aboveground carbon toward the end of the monitoring period. Conclusion: Prolonged droughts influence the mortality of large trees, leading to a decline in aboveground carbon stocks. Here, and in other neotropical forests, recent droughts are capable of shutting down and reversing biomass carbon sinks. These new results add to evidence that anthropogenic climate changes are already adversely impacting tropical forests.

Lesbian, gay, bisexual, transgender, queer and/or questioning, intersex, and asexual (LGBTQIA) youth are more likely than cisgender heterosexual youth to experience traumatic stress across all social systems, including within family, school, and health care settings. LGBTQIA youth may be particularly susceptible to traumatic stressors associated with medical illness or injury and health care, due to both to higher baseline levels of stress and adversity and unique identity-linked stressors pervasive across systems of care. Pediatric providers can greatly impact mental health in their LGBTQIA patients by providing trauma-informed care that is affirming of gender and sexual identities. This article presents foundational concepts pertaining to medical trauma and practice priorities for pediatric providers, who are uniquely positioned to mitigate medical traumatic stress experienced by LGBTQIA youth. [ Pediatr Ann . 2021;50(9):e379–e383.]

Background: Adolescents today have unprecedented and uninterrupted access to news and current events through broadcast and social media. Lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQ) adolescents may be especially cognizant of media and public discourse pertaining to law and policy changes affecting the legal rights of their communities. The minority stress framework explains how sociopolitical discourse impacts mental health among sexual and gender minority youths. Objectives: This paper identifies and describes contemporary sociopolitical and legal issues that may impact LGBTQ adolescents’ mental health. Methods: Authors describe the minority stress framework as applied to gender and sexual identity and explore key sociopolitical and legal topics relevant to LGBTQ adolescents, including employment; medical care bans; health insurance coverage; conversion therapy; religious exemptions in health care; housing rights; and rights in schools and school districts, including participation in sports. Results: LGBTQ youth experience rejection, prejudice, and discrimination directly through adverse legislative or administrative action and more pervasively through the dominant cultural beliefs and sociopolitical messaging that such developments manifest. Conclusion: Mental health clinicians who are aware of legal issues and sociopolitical debate pertinent to LGBTQ rights are better prepared to address their significant impact on LGBTQ adolescents’ mental health.