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Cover page of Introduction youth language at the intersection

Introduction youth language at the intersection

(2022)

This special issue examines the linguistic production of youth identities under conditions of cultural mobility. Building on theories of migration, transnationalism, and globalization that have emerged in anthropology, cultural studies, and other fields, the contributions to the special issue investigate not simply the large-scale cultural and political processes that shape the lives of youth but equally how youth identities emerge through the fine-grained details of interactional work and local linguistic practice. The introduction lays out the major themes that run through the special issue: the importance of scholarly attentiveness to the diversity of youth identities; the recognition of youth as social agents moving across national boundaries both physically and symbolically; the role of local ethnographic practice in investigations of global and transnational phenomena and especially the centrality of interaction as the primary site of social life; and the significance of language as a key resource for the articulation and negotiation of social identities, relations, and processes.

Cover page of Foundations for California's Water Security in a Changing Climate

Foundations for California's Water Security in a Changing Climate

(2022)

California’s water supplies are facing unprecedented stresses, and the state’s water-management systems are struggling to meet both environmental and human needs (agricultural, municipal, industrial). Supplies are highly vulnerable to climate variability and extreme events, limiting options to respond to the combined stresses of a changing climate, population, and land cover. Strategic, coordinated investments in California’s water infrastructure, institutions, and information will provide the foundation for a secure, equitable, and efficient water future. The cornerstone of water security, and priority need for California, is a modern, robust water-information system that enables accurate, timely, and transparent accounting through the water-supply and use cycle. This system must extend from mountain headwaters through valley groundwater. Investments are also needed in capacity building for use of water information among institutions and stakeholders across the state. Priority infrastructure improvements are needed for central elements of the state’s “green” infrastructure: restoration of Sierra Nevada and other forests in source-water areas, and additional groundwater recharge on farmland and expanded floodplains. With better-informed management, California’s existing water supplies could go further to meeting the state’s urban, agricultural, ecological, and industrial needs.

Cover page of Symbiotic organs: the nexus of host-microbe evolution.

Symbiotic organs: the nexus of host-microbe evolution.

(2022)

Diverse plants and animals have evolved specialized structures to filter and house beneficial microbes. These symbiotic organs form crucial points of exchange between host and symbiont, are often shaped by both partners, and exhibit features that facilitate a suite of microbial services. While symbiotic organs exhibit varied function, morphology, and developmental plasticity, they share core features linked to the evolutionary maintenance of beneficial symbiosis. Moreover, these organs can have a significant role in altering the demographic forces that shape microbial genomes, driving population bottlenecks and horizontal gene transfer (HGT). To advance our understanding of these 'joint phenotypes' across varied systems, future research must consider the emergent forces that can shape symbiotic organs, including fitness feedbacks and conflicts between interacting genomes.

Fungi are key players in extreme ecosystems.

(2022)

Extreme environments on Earth are typically devoid of macro life forms and are inhabited predominantly by highly adapted and specialized microorganisms. The discovery and persistence of these extremophiles provides tools to model how life arose on Earth and inform us on the limits of life. Fungi, in particular, are among the most extreme-tolerant organisms with highly versatile lifestyles and stunning ecological and morphological plasticity. Here, we overview the most notable examples of extremophilic and stress-tolerant fungi, highlighting their key roles in the functionality and balance of extreme ecosystems. The remarkable ability of fungi to tolerate and even thrive in the most extreme environments, which preclude most organisms, have reshaped current concepts regarding the limits of life on Earth.

Cover page of Ambient air pollution exposure and increasing depressive symptoms in older women: The mediating role of the prefrontal cortex and insula.

Ambient air pollution exposure and increasing depressive symptoms in older women: The mediating role of the prefrontal cortex and insula.

(2022)

Exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) have been associated with the emergence of depressive symptoms in older adulthood, although most studies used cross-sectional outcome measures. Elucidating the brain structures mediating the adverse effects can strengthen the causal role between air pollution and increasing depressive symptoms. We evaluated whether smaller volumes of brain structures implicated in late-life depression mediate associations between ambient air pollution exposure and changes in depressive symptoms. This prospective study included 764 community-dwelling older women (aged 81.6 ± 3.6 in 2008-2010) from the Women's Health Initiative Memory Study (WHIMS) Magnetic Resonance Imaging study (WHIMS-MRI; 2005-06) and WHIMS-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO; 2008-16). Three-year average annual mean concentrations (scaled by interquartile range [IQR]) of ambient PM2.5 (in μg/m3; IQR = 3.14 μg/m3) and NO2 (in ppb; IQR = 7.80 ppb) before WHIMS-MRI were estimated at participants' addresses via spatiotemporal models. Mediators included structural brain MRI-derived grey matter volumes of the prefrontal cortex and structures of the limbic-cortical-striatal-pallidal-thalamic circuit. Depressive symptoms were assessed annually by the 15-item Geriatric Depression Scale. Structural equation models were constructed to estimate associations between exposure, structural brain volumes, and depressive symptoms. Increased exposures (by each IQR) were associated with greater annual increases in depressive symptoms (βPM2.5 = 0.022; 95% Confidence Interval (CI) = 0.003, 0.042; βNO2 = 0.019; 95% CI = 0.001, 0.037). The smaller volume of prefrontal cortex associated with exposures partially mediated the associations of increased depressive symptoms with NO2 (8%) and PM2.5 (13%), and smaller insula volume associated with NO2 contributed modestly (13%) to the subsequent increase in depressive symptoms. We demonstrate the first evidence that the smaller volumes of the prefrontal cortex and insula may mediate the subsequent increases in depressive symptoms associated with late-life exposures to NO2 and PM2.5.

Mouse circulating extracellular vesicles contain virus-derived siRNAs active in antiviral immunity.

(2022)

Induction and suppression of antiviral RNA interference (RNAi) has been observed in mammals during infection with at least seven distinct RNA viruses, including some that are pathogenic in humans. However, while the cell-autonomous immune response mediated by antiviral RNAi is gradually being recognized, little is known about systemic antiviral RNAi in mammals. Furthermore, extracellular vesicles (EVs) also function in viral signal spreading and host immunity. Here, we show that upon antiviral RNAi activation, virus-derived small-interfering RNAs (vsiRNAs) from Nodamura virus (NoV), Sindbis virus (SINV), and Zika virus (ZIKV) enter the murine bloodstream via EVs for systemic circulation. vsiRNAs in the EVs are biologically active, since they confer RNA-RNA homology-dependent antiviral activity in both cultured cells and infant mice. Moreover, we demonstrate that vaccination with a live-attenuated virus, rendered deficient in RNAi suppression, induces production of stably maintained vsiRNAs and confers protective immunity against virus infection in mice. This suggests that vaccination with live-attenuated VSR (viral suppressor of RNAi)-deficient mutant viruses could be a new strategy to induce immunity.

Cover page of The air-inactivation of formate dehydrogenase FdsDABG from Cupriavidus necator.

The air-inactivation of formate dehydrogenase FdsDABG from Cupriavidus necator.

(2022)

The nature of air-inactivation of the formate dehydrogenase FdsDABG from Cupriavidus necator has been investigated. It is found that superoxide, generated in the reaction of reduced enzyme with oxygen, is responsible for the loss of activity and that superoxide dismutase protects the enzyme from air-inactivation. Inhibition appears to be due to the reaction of superoxide with the catalytically essential MoS group of the enzyme's molybdenum center in such a way that generates sulfite. SYNOPSIS: Superoxide generated in the reaction of reduced formate dehydrogenase FdsDABG from Cupriavidus necator with O2 is found to be responsible for the loss of activity. Catalytic amounts of superoxide dismutase are found to protect FdsDABG just as well as more generally used stabilizing inhibitors such as nitrate.