Quantifying the drivers of ocean-atmosphere CO2 fluxes

A mechanistic framework for quantitatively mapping the regional drivers of air-sea CO2 fluxes at a global scale is developed. The framework evaluates the interplay between (1) surface heat and freshwater fluxes that influence the potential saturated carbon concentration, which depends on changes in sea surface temperature, salinity and alkalinity, (2) a residual, disequilibrium flux influenced by upwelling and entrainment of remineralized carbon- and nutrient-rich waters from the ocean interior, as well as rapid subduction of surface waters, (3) carbon uptake and export by biological activity as both soft tissue and carbonate, and (4) the effect on surface carbon concentrations due to freshwater precipitation or evaporation. In a steady state simulation of a coarse-resolution ocean circulation and biogeochemistry model, the sum of the individually determined components is close to the known total flux of the simulation. The leading order balance, identified in different dynamical regimes, is between the CO2 fluxes driven by surface heat fluxes and a combination of biologically driven carbon uptake and disequilibrium-driven carbon outgassing. The framework is still able to reconstruct simulated fluxes when evaluated using monthly averaged data and takes a form that can be applied consistently in models of different complexity and observations of the ocean. In this way, the framework may reveal differences in the balance of drivers acting across an ensemble of climate model simulations or be applied to an analysis and interpretation of the observed, real-world air-sea flux of CO2

Cytotoxic Activity of Paris quadrifolia Extract and Isolated Saponin Fractions Against Human Tumor Cell Lines

Steroidal saponins isolated from many plant species belonging to Monocotyledones display potent cytotoxic activity towards many human tumor cells. We examined the cytotoxic effects of crude Paris quadrifolia extract for the first time, testing isolated saponin-rich fractions against four different human cell lines using the [(3-(4,5- dimethylthiazol-2-yl)]-2,5-diphenyltetrazolium bromide (MTT) assay. Cytotoxic activity was tested against human promyelocytic leukemia (HL-60) cells, human cervical adenocarcinoma (HeLa) cells and human breast cancer (MDA-MB-468) cells. Human skin fibroblasts were used as non-neoplastic control cells. Our results show significant activity of the weakly water-soluble solid residue and butanolic fraction against HL-60 and HeLa cells. The solid residue exerted cytotoxicity against all tested cell lines

How do Workers with Common Mental Disorders Experience a Multidisciplinary Return-to-Work Intervention? A Qualitative Study

Purpose Long-term sick leave due to common mental disorders (CMD) is an increasing problem in many countries. Recent reviews indicate that return to work (RTW) interventions have limited effect on reducing sickness absence among this group of sick-listed. The aims of this study were to investigate how sick-listed persons with CMD experienced participating in an RTW intervention and how workability assessments and RTW activities influenced their RTW-process, and to examine the working mechanisms of the intervention. The gained knowledge can help improve future RTW intervention design and implementation. Methods In-depth interviews were conducted with 17 participants on sick leave due to CMD who participated in an RTW intervention. Interviews were conducted at three time points with each participant. Principles of interpretative phenomenological analyses guided the analysis. Results The workability assessment consultations and RTW activities such as psychoeducative group sessions and individual sessions with psychologist could result in both motivation and frustration depending on the extent to which the RTW professionals practiced what we have termed an individual approach to the sicklisted person. Conclusions The individual approach seems necessary for the realization of the positive potential in the RTW intervention. However, the fact that RTW professionals are both the facilitators and the controllers of the sick-listed persons’ RTW process is an inherent paradox in the intervention, which can impede the necessary establishment of a high-quality relationship between the sicklisted persons and RTW professionals