Characterizing the momentary association between loneliness, depression, and social interactions: Insights from an ecological momentary assessment study.

Evidence suggests that loneliness causes people to feel more depressed. It is unknown, however, why this association occurs and whether momentary versus chronic experiences of loneliness are implicated. Theoretical accounts suggest that momentary feelings of loneliness produce two competing motivations: social reaffiliation and social withdrawal.

An Automated Virtual Reality Program Accurately Diagnoses HIV-Associated Neurocognitive Disorders in Older People With HIV.

Background: HIV-associated neurocognitive disorders (HANDs) remain prevalent despite antiretroviral therapy, particularly among older people with HIV (PWH). However, the diagnosis of HAND is labor intensive and requires expertise to administer neuropsychological tests. Our prior pilot work established the feasibility and accuracy of a computerized self-administered virtual reality program (DETECT; Display Enhanced Testing for Cognitive Impairment and Traumatic Brain Injury) to measure cognition in younger PWH.

Practical Guide to Measuring Wetland Carbon Pools and Fluxes.

Unlabelled: Wetlands cover a small portion of the world, but have disproportionate influence on global carbon (C) sequestration, carbon dioxide and methane emissions, and aquatic C fluxes. However, the underlying biogeochemical processes that affect wetland C pools and fluxes are complex and dynamic, making measurements of wetland C challenging. Over decades of research, many observational, experimental, and analytical approaches have been developed to understand and quantify pools and fluxes of wetland C.

Mild Cognitive Impairment, But Not HIV Status, is Related to Reduced Awareness of Level of Cognitive Performance Among Older Adults.

Objective: Self-assessment of cognitive abilities can be an important predictor of clinical outcomes. This study examined impairments in self-assessments of cognitive performance, assessed with traditional neuropsychological assessments and novel virtual reality tests among older persons with and without human immunodeficiency virus (HIV) and mild cognitive impairment (MCI).

Methods: One hundred twenty-two participants (82 persons with HIV; 79 MCI+) completed a traditional neuropsychological battery, DETECT virtual reality cognitive battery, and self-reported their general cognitive complaints, depressive symptoms, and perceptions of DETECT performance.

Dirt cheap: an experimental test of controls on resource exchange in an ectomycorrhizal symbiosis.

To distinguish among hypotheses on the importance of resource-exchange ratios in outcomes of mutualisms, we measured resource (carbon (C), nitrogen (N), and phosphorus (P)) transfers and their ratios, between Pinus taeda seedlings and two ectomycorrhizal (EM) fungal species, Rhizopogon roseolus and Pisolithus arhizus in a laboratory experiment. We evaluated how ambient light affected those resource fluxes and ratios over three time periods (10, 20, and 30 wk) and the consequences for plant and fungal biomass accrual, in environmental chambers. Our results suggest that light availability is an important factor driving absolute fluxes of N, P, and C, but not exchange ratios, although its effects vary among EM fungal species.

Distress among undergraduates: Marginality, stressors and resilience resources.

This study addresses mental health concerns among university students, examining cumulative stress exposure as well as resilience resources. : Participants were 253 first- and second-year undergraduate students (age = 18.76; 49.

College from home during COVID-19: A mixed-methods study of heterogeneous experiences.

This mixed-method study examined the experiences of college students during the COVID-19 pandemic through surveys, experience sampling data collected over two academic quarters (Spring 2019 n1 = 253; Spring 2020 n2 = 147), and semi-structured interviews with 27 undergraduate students. There were no marked changes in mean levels of depressive symptoms, anxiety, stress, or loneliness between 2019 and 2020, or over the course of the Spring 2020 term. Students in both the 2019 and 2020 cohort who indicated psychosocial vulnerability at the initial assessment showed worse psychosocial functioning throughout the entire Spring term relative to other students.

Brown meets green: light and nutrients alter detritivore assimilation of microbial nutrients from leaf litter.

In aquatic detrital-based food webs, research suggests that autotroph-heterotroph microbial interactions exert bottom-up controls on energy and nutrient transfer. To address this emerging topic, we investigated microbial responses to nutrient and light treatments during Liriodendron tulipifera litter decomposition and fed litter to the caddisfly larvae Pycnopsyche sp. We measured litter-associated algal, fungal, and bacterial biomass and production.

Functional importance and diversity of fungi during standing grass litter decomposition.

Although microbial participation in litter decomposition is widely known within terrestrial soils, the role and significance of microorganisms during the aerial standing litter phase of decomposition remains poorly investigated. We examined the fungi inhabiting standing leaf litter of Schizachyrium scoparium and Schizachyrium tenerum in a Longleaf Pine savanna ecosystem and estimated their contribution to litter decomposition. We identified fungal phylotypes associated with leaf litter and quantified leaf C mass loss, fungal biomass production, and microbial respiration during decomposition.

Cross-Study, Cross-Method Associations Between Negative Urgency and Internalizing Symptoms.

There is a small body of research that has connected individual differences in negative urgency, the tendency to report rash actions in response to negative emotions, with self-report depressive and anxiety symptoms. Despite the conceptual overlap of negative urgency with negative emotionality, the tendency to experience frequent and intense negative emotions, even fewer studies have examined whether the association of negative urgency with internalizing symptoms hold when controlling for negative emotionality. In the current study, we estimated the bivariate association between negative urgency and internalizing symptoms, tested whether they remained significant after partialling out negative emotionality, and tested whether these effects generalized to real-time experiences of negative emotions.

Filter-feeders have differential bottom-up impacts on green and brown food webs.

Nutrient recycling by consumers can strongly impact nutrient availability for autotrophic and heterotrophic microbes, thus impacting functions such as primary production and decomposition. Filter-feeding freshwater mussels form dense, multispecies assemblages in aquatic ecosystems and have been shown to play a critical role in nutrient cycling. Mussel excretion can enhance benthic primary production and influence algal species composition.

Periphytic algae decouple fungal activity from leaf litter decomposition via negative priming.

1. Well-documented in terrestrial settings, priming effects describe stimulated heterotrophic microbial activity and decomposition of recalcitrant carbon by additions of labile carbon. In aquatic settings, algae produce labile exudates which may elicit priming during organic matter decomposition, yet the directions and mechanisms of aquatic priming effects remain poorly tested.

Passively-sensed Behavioral Correlates of Discrimination Events in College Students.

A deep understanding of how discrimination impacts psychological health and well-being of students could allow us to better protect individuals at risk and support those who encounter discrimination. While the link between discrimination and diminished psychological and physical well-being is well established, existing research largely focuses on chronic discrimination and long-term outcomes. A better understanding of the short-term behavioral correlates of discrimination events could help us to concretely quantify such experiences, which in turn could support policy and intervention design.

Emotion regulation processes linking peer victimization to anxiety and depression symptoms in adolescence.

Difficulties with emotion regulation can take many forms, including increased sensitivity to emotional cues and habitual use of maladaptive cognitive or behavioral regulation strategies. Despite extensive research on emotion regulation and youth adjustment, few studies integrate multiple measures of emotion regulation. The present study evaluated the underlying structure of emotion regulation processes in adolescence using both task- and survey-based measures and determined whether differences in these emotion regulation latent factors mediated the association between peer victimization and internalizing psychopathology.

Changes in nutrient stoichiometry, elemental homeostasis and growth rate of aquatic litter-associated fungi in response to inorganic nutrient supply.

Aquatic fungi mediate important energy and nutrient transfers in freshwater ecosystems, a role potentially altered by widespread eutrophication. We studied the effects of dissolved nitrogen (N) and phosphorus (P) concentrations and ratios on fungal stoichiometry, elemental homeostasis, nutrient uptake and growth rate in two experiments that used (1) liquid media and a relatively recalcitrant carbon (C) source and (2) fungi grown on leaf litter in microcosms. Two monospecific fungal cultures and a multi-species assemblage were assessed in each experiment.

Discrimination in Degradability of Soil Pyrogenic Organic Matter Follows a Return-On-Energy-Investment Principle.

A fundamental understanding of biodegradability is central to elucidating the role(s) of pyrogenic organic matter (PyOM) in biogeochemical cycles. Since microbial community and ecosystem dynamics are driven by net energy flows, then a quantitative assessment of energy value versus energy requirement for oxidation of PyOM should yield important insights into their biodegradability. We used bomb calorimetry, stepwise isothermal thermogravimetric analysis (isoTGA), and 5-year in situ bidegradation data to develop energy-biodegradability relationships for a suite of plant- and manure-derived PyOM (n = 10).

Ectomycorrhizal fungal mycelia turnover in a longleaf pine forest.

Elucidation of the patterns and controls of carbon (C) flow and nitrogen (N) cycling in forests has been hindered by a poor understanding of ectomycorrhizal fungal mycelia (EFM) dynamics. In this study, EFM standing biomass (based on soil ergosterol concentrations), production (based on ergosterol accrual in ingrowth cores), and turnover rate (the quotient of annual production and average standing biomass estimates) were assessed in a 25-yr-old longleaf pine (Pinus palustris) plantation where C flow was manipulated by foliar scorching and N fertilization for 5 yr before study initiation. In the controls, EFM standing biomass was 30 ± 7 g m(-2) , production was 279 ± 63 g m(-2)  yr(-1) , and turnover rate was 10 ± 3 times yr(-1) .