38 research outputs found
Suspended particles are hotspots of microbial remineralization in the ocean's twilight zone
The sinking of photosynthetically produced organic carbon from the ocean surface to its interior is a significant term in the global carbon cycle. Most sinking organic carbon is, however, remineralized in the mesopelagic zone (âŒ100 mâ1000 m), thereby exerting control over ocean-atmosphere carbon dioxide (CO2) partitioning and hence global climate. Sinking particles are considered hotspots of microbial respiration in the dark ocean. However, our observations in the contrasting Scotia Sea and the Benguela Current show that >90% of microbial remineralisation is associated with suspended, rather than sinking, organic matter, resulting in rapid turnover of the suspended carbon pool and demonstrating its central role in mesopelagic carbon cycling. A non-steady-state model indicates that temporally variable particle fluxes, particle injection pumps and local chemoautotrophy are necessary to help balance the observed mesopelagic respiration. Temperature and oxygen exert control over microbial respiration, particularly for the suspended fraction, further demonstrating the susceptibility of microbial remineralisation to the ongoing decline in oxygen at mid-ocean depths. These observations suggest a partial decoupling of carbon cycling between non-sinking and fast-sinking organic matter, challenging our understanding of how oceanic biological processes regulate climate
TRY plant trait database â enhanced coverage and open access
Plant traitsâthe morphological, anatomical, physiological, biochemical and phenological characteristics of plantsâdetermine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traitsâalmost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Caught in between:neoliberal rhetoric and middle-income families in Canada and the United States
In both Canada and the United States, middle-income families feel neglected by policymakers but struggle to balance their financial need and desire for government support on the one hand with neoliberal beliefs in self-reliance and self-responsibility on the other. The focus of this paper is on the tensions experienced by middle-income participants in both countries as they try to negotiate a place for themselves amid these competing discourses. Specifically, this paper analyzes participantsâ struggle to juxtapose their place in the âshrinking' or âforgotten' middle class, against their desire to be âgood' citizens who take responsibility for themselves and their families. This analysis plays out against the backdrop of different socio-political environments and in the context of the 2007â2009 global recession which exacerbated the already increasing pressure on the middle class. It is argued that these contexts have shaped how participants in each country feel about the government support they require, deserve, and reject
The distribution and production of Gammarus pseudolimnaeus (Crustacea: Amphipoda) along a reach of the Credit River, Ontario
Attitudes toward capital punishment: Educational, demographic, and neighborhood crime influences
The design and uses of an employability index to evaluate the vertical workforce development process
BenzocaĂna e eugenol como anestĂ©sicos para o quinguio (Carassius auratus)
Avaliaram-se os tempos de indução e recuperação de quinguios (Carassius auratus) expostos a dois anestĂ©sicos, eugenol e benzocaĂna. Foram utilizados 128 juvenis com peso mĂ©dio de 2,07±0,53g e comprimento total mĂ©dio de 5,51±0,56cm. A benzocaĂna mostrou ser mais eficiente do que o eugenol em relação ao tempo, tanto para indução ao coma quanto para a recuperação Ă fuga e tambĂ©m no que diz respeito Ă sobrevivĂȘncia. As doses de benzocaĂna com melhores resultados foram de 87,5 e 100mg.L-1. O eugenol proporcionou demora na indução e na recuperação dos animais, alĂ©m de ter apresentado mortalidades quando as doses anestĂ©sicas foram elevadas