198,932 research outputs found
Carbonyl sulfide (COS) as a tracer for canopy photosynthesis, transpiration and stomatal conductance : potential and limitations
No full textThe theoretical basis for the link between the leaf exchange of carbonyl sulfide (COS), carbon dioxide (CO2) and water vapour (H2O) and the assumptions that need to be made in order to use COS as a tracer for canopy net photosynthesis, transpiration and stomatal conductance, are reviewed. The ratios of COS to CO2 and H2O deposition velocities used to this end are shown to vary with the ratio of the internal to ambient CO2 and H2O mole fractions and the relative limitations by boundary layer, stomatal and internal conductance for COS. It is suggested that these deposition velocity ratios exhibit considerable variability, a finding that challenges current parameterizations, which treat these as vegetation-specific constants. COS is shown to represent a better tracer for CO2 than H2O. Using COS as a tracer for stomatal conductance is hampered by our present poor understanding of the leaf internal conductance to COS. Estimating canopy level CO2 and H2O fluxes requires disentangling leaf COS exchange from other ecosystem sources/sinks of COS. We conclude that future priorities for COS research should be to improve the quantitative understanding of the variability in the ratios of COS to CO2 and H2O deposition velocities and the controlling factors, and to develop operational methods for disentangling ecosystem COS exchange into contributions by leaves and other sources/sinks. To this end, integrated studies, which concurrently quantify the ecosystem-scale CO2, H2O and COS exchange and the corresponding component fluxes, are urgently needed.
We investigate the potential of carbonyl sulfide (COS) for being used as a tracer for canopy net photosynthesis, transpiration and stomatal conductance by examining the theoretical basis of the link between leaf COS, carbon dioxide (CO2) and water vapour (H2O) exchange. Our analysis identifies several limitations that need to be overcome to this end, however at present we lack appropriate ecosystem-scale field measurements for assessing their practical significance. It however appears that COS represents a better tracer for CO2 than H2O. Concurrent measurements of ecosystem scale COS, CO2 and H2O exchange are advocated
J-Cos/Alladale_Paper: v1.0.0
No full text<p>First release of completed analysis - figure remain indicative.</p>
J-Cos/Alladale_Paper: v1.3.0
No full text<p>Updates in response to peer review at "Ecological Solutions and Evidence".</p>
<p><strong>Full Changelog</strong>: https://github.com/J-Cos/Alladale_Paper/compare/v1.2.0...v1.3.0</p>
Characterization of Frobenius Groups of Special Type
No full textWe define a Con-Cos group G to be one having a proper
normal subgroup N whose cosets other than N itself are conjugacy classes. It follows easily that N = G’, the derived group of G. Most of the paper is devoted to trying to classify finite Con-Cos groups satisfying the additional requirement that N has just two conjugacy classes. We show that for such groups the center Z(G) has order at most 2, and if Z(G) = {1}, then G is a Frobenius group of a rather special type.</p
Disentangling the rates of carbonyl sulfide (COS) production and consumption and their dependency on soil properties across biomes and land use types
No full textSoils both emit and consume the trace gas carbonyl sulfide (COS) leading to a soil-air COS exchange rate that is the net result of two opposing fluxes. Partitioning these two gross fluxes and understanding their drivers are necessary to estimate the contribution of soils to the current and future atmospheric COS budget.
Previous efforts to disentangle the gross COS fluxes from soils have used flux measurements on air-dried soils as a proxy for the COS emission rates of moist soils. However, this method implicitly assumes that COS uptake becomes negligible and that COS emission remains steady while soils are drying. We tested this assumption by simultaneously estimating the soil COS sources and sinks and their temperature sensitivity (Q(10)); these estimates were based on soil-air COS flux measurements on fresh soils at different COS concentrations and two soil temperatures. Measurements were performed on 27 European soils from different biomes and land use types in order to obtain a large range of physical-chemical properties and identify the drivers of COS consumption and production rates.
We found that COS production rates from moist and air-dried soils were not significantly different for a given soil and that the COS production rates had Q(10) values (3.96 +/- 3.94) that were larger and more variable than the Q(10) for COS consumption (1.17 +/- 0.27). COS production generally contributed less to the net flux at lower temperatures but this contribution of COS production increased rapidly at higher temperatures, lower soil moisture contents and lower COS concentrations. Consequently, measurements at higher COS concentrations (viz. 1000 ppt) always increased the robustness of COS consumption estimates. Across the range of biomes and land use types COS production rates co-varied with total soil nitrogen concentrations (r = 0.52, P < 0.05) and mean annual precipitation (r = 0.53, P < 0.05), whilst the gross COS uptake rate and the first-order COS hydrolysis rate constant co-varied significantly with the microbial biomass nitrogen (N) content of the soils (r = 0.74 and 0.64, P < 0.05 and P < 0.05, respectively). Collectively our findings suggest a strong interaction between soil nitrogen and water cycling on COS production and uptake, providing new insights into how to upscale the contribution of soils to the global atmospheric COS budget
The flux of carbonyl sulfide and carbon disulfide between the atmosphere and a spruce forest
No full textTurbulent fluxes of carbonyl sulfide (COS) and carbon disulfide (CS2) were measured over a spruce forest in Central Germany using the relaxed eddy accumulation (REA) technique. A REA sampler was developed and validated using simultaneous measurements of CO2 fluxes by REA and by eddy correlation. REA measurements were conducted during six campaigns covering spring, summer, and fall between 1997 and 1999. Both uptake and emission of COS and CS2 by the forest were observed, with deposition occurring mainly during the sunlit period and emission mainly during the dark period. On the average, however, the forest acts as a sink for both gases. The average fluxes for COS and CS2 are -93 ± 11.7 pmol m-2 s-1 and -18 ± 7.6 pmol m-2 s-1, respectively. The fluxes of both gases appear to be correlated to photosynthetically active radiation and to the CO2 and \chem{H_2O} fluxes, supporting the idea that the air-vegetation exchange of both gases is controlled by stomata. An uptake ratio COS/CO2 of 10 ± 1.7 pmol m mol-1 has been derived from the regression line for the correlation between the COS and CO2 fluxes. This uptake ratio, if representative for the global terrestrial net primary production, would correspond to a sink of 2.3 ± 0.5 Tg COS yr-1
Parent and practitioner perspectives on Circle of Security Parenting (COS‐P): A qualitative study
No full textCircle of Security Parenting (COS-P) is an attachment-theory-informed program for parents of infants and young children. Designed for scalability, COS-P has been widely adopted internationally. Evidence for the program's effectiveness is limited, however, restricting capacity to make informed decisions about program allocation, and threatening ongoing program funding. To help address this evidence gap, this qualitative study explored the experiences and perceptions of 20 COS-P facilitators and 14 parent recipients in Australia, where COS-P uptake has been particularly widespread. Thematic analysis of combined interview and focus group data revealed a perception that COS-P primarily changes the lens through which parents view (a) their child, (b) themselves in the parenting role, and (c) the parent–child relationship, and that this was a pathway to increased empathy, compassion, and parenting confidence. Participants identified four components that underpinned program impact: key content, skills practice, group processes, and facilitator support. Although COS-P was considered suitable for broad application, limitations were noted. Findings can guide clinical application of COS-P and inform empirical research.This study was aided by an Australian GovernmentResearch Training Scholarship and the Macquarie Uni-versity Higher Degree Research Fun
COS-_Supplemental_Material – Supplemental material for Repertoires of political participation: Macroeconomic conditions, socioeconomic resources, and participation gaps in Europe
No full textSupplemental material, COS-_Supplemental_Material for Repertoires of political participation: Macroeconomic conditions, socioeconomic resources, and participation gaps in Europe by Mario Quaranta in International Journal of Comparative Sociology</p
Un cos amb nyaps
No full textEl Poema de Gilgamesh, escrit al voltant de l'any 1400 aC a partir de diversos textos sumeris més antics, és un dels primers de què es té constància escrita. No obstant, el més antic que es conserva, de fa més de 4.000 anys, va ser escrit per una poetessa, la princesa Enheduanna, de la ciutat d'Ur, que va viure al segle XXIII aC. La capacitat de fer poesia, així com de qualsevol altra manifestació artística, filosòfica o científica, està associada a un òrgan molt curiós del nostre cos, el cervell. Dic que és curiós per dos motius: d'una banda, perquè fa que sentim una gran curiositat per tot allò que ens envolta, i d'una altra, perquè la seva estructura i funcionalitat són també intrínsecament curioses. Per satisfer la curiositat dels més encuriosits, aquest mes us vull presentar dos llibres d'una mateixa col·lecció que es caracteritzen, precisament, per complaure i alhora estimular la curiositat del lector, relacionats amb el cos i el cervell humà
Effects of the ‘Circle of Security’ group parenting program (COS-P) with foster carers: An observational study
No full textThe Circle of Security-Parent DVD program (COS-P) is a widely used parenting intervention that is gaining popularity globally as it is currently being delivered across several continents. Despite the uptake of COS-P, there is limited research on its effectiveness for specific groups. Here we present a multi-site evaluation of a group delivery of the eight-week COS-P program to foster carers (n = 54) of 6–12 year-old children in an urban community as facilitated by community-based providers from a specialist child and youth mental health services (n = 2). Three measures, the Parent Stress Index, the Parent Child Relationship Inventory, and the Strengths and Difficulties Questionnaire, were used to assess functioning via a pre-post treatment design. Foster carers who participated in COS-P reported reductions in levels of emotional and behavioural difficulties for the children in their care. They also reported reductions in parent–child dysfunctional interactions and parental distress. Finally, program completion appeared to be associated with a reduction in foster carers’ perceptions of their foster child as being difficult to take care of, and with lower levels of overall stress related to their role as a foster carer. These findings, and their implications for service delivery and future research, are discussed
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