Effects of Trophic Skewing of Species Richness on Ecosystem Functioning in a Diverse Marine Community

Widespread overharvesting of top consumers of the world’s ecosystems has “skewed” food webs, in terms of biomass and species richness, towards a generally greater domination at lower trophic levels. This skewing is exacerbated in locations where exotic species are predominantly low-trophic level consumers such as benthic macrophytes, detritivores, and filter feeders. However, in some systems where numerous exotic predators have been added, sometimes purposefully as in many freshwater systems, food webs are skewed in the opposite direction toward consumer dominance. Little is known about how such modifications to food web topology, e.g., changes in the ratio of predator to prey species richness, affect ecosystem functioning. We experimentally measured the effects of trophic skew on production in an estuarine food web by manipulating ratios of species richness across three trophic levels in experimental mesocosms. After 24 days, increasing macroalgal richness promoted both plant biomass and grazer abundance, although the positive effect on plant biomass disappeared in the presence of grazers. The strongest trophic cascade on the experimentally stocked macroalgae emerged in communities with a greater ratio of prey to predator richness (bottom-rich food webs), while stronger cascades on the accumulation of naturally colonizing algae (primarily microalgae with some early successional macroalgae that recruited and grew in the mesocosms) generally emerged in communities with greater predator to prey richness (the more top-rich food webs). These results suggest that trophic skewing of species richness and overall changes in food web topology can influence marine community structure and food web dynamics in complex ways, emphasizing the need for multitrophic approaches to understand the consequences of marine extinctions and invasions

Loss of Mir146b with aging contributes to inflammation and mitochondrial dysfunction in thioglycollate-elicited peritoneal macrophages

Macrophages undergo programmatic changes with age, leading to altered cytokine polarization and immune dysfunction, shifting these critical immune cells from protective sentinels to disease promoters. The molecular mechanisms underlying macrophage inflammaging are poorly understood. Using an unbiased RNA sequencing (RNA-seq) approach, we identifie

Healthcare workers' perception of gender and work roles during the COVID-19 pandemic: A mixed-methods study

Objectives A high functioning healthcare workforce is a key priority during the COVID-19 pandemic. We sought to determine how work and mental health for healthcare workers changed during the COVID-19 pandemic in a universal healthcare system, stratified by gender factors. Design A mixed-methods study was employed. Phase 1 was an anonymous, internet-based survey (7 May-15 July 2020). Phase 2 was semistructured interviews offered to all respondents upon survey completion to describe how experiences may have differed by gender identity, roles and relations. Setting National universal healthcare system (Canada). Participants 2058 Canadian healthcare worker survey respondents (87% women, 11% men, 1% transgender or Two-Spirit), including 783 health professionals, 673 allied health professionals, 557 health support staff. Of the 63 unique healthcare worker types reported, registered nurses (11.5%), physicians (9.9%) and pharmacists (4.5%) were most common. Forty-six healthcare workers were interviewed. Main outcome measures Reported pandemic-induced changes to occupational leadership roles and responsibilities, household and caregiving responsibilities, and anxiety levels by gender identity. Results Men (19.8%) were more likely to hold pandemic leadership roles compared with women (13.4%). Women (57.5%) were more likely to report increased domestic responsibilities than men (45%). Women and those with dependents under the age of 10 years reported the greatest levels of anxiety during the pandemic. Interviews with healthcare workers further revealed a perceived imbalance in leadership opportunities based on gender identity, a lack of workplace supports disproportionately affecting women and an increase in domestic responsibilities influenced by gender roles. Conclusions The COVID-19 pandemic response has important gendered effects on the healthcare workforce. Healthcare workers are central to effective pandemic control, highlighting an urgent need for a gender-transformative pandemic response strategy