911 research outputs found

    Seasonal contribution of terrestrial organic matter and biological oxygen demand to the Baltic Sea from three contrasting river catchments

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    To examine the potential influence of terrestrially derived DOM on the Baltic Sea, a year-long study of dissolved organic matter (DOM) was performed in three river catchments in Sweden. One catchment drains into the Bothnian Sea, while two southern catchments drain into the Baltic proper. Dissolved organic carbon (DOC) concentrations were positively correlated with discharge from forested catchments over the year. While the overall concentrations of DOC were several times higher in the southern two catchments, higher discharge in the northern catchment resulted in the annual loadings of DOC being on the same order of magnitude for all three catchments. Biological oxygen demand (BOD) was used as a proxy for the lability of carbon in the system. The range of BOD values was similar for all three catchments, however, the ratio of BOD to DOC (an indication of the labile fraction) in Ume river was four times higher than in the southern two catchments. Total annual BOD loading to the Baltic Sea was twice as high in the northern catchment than in the two southern catchments. Lower winter temperatures and preservation of organic matter in the northern catchment combined with an intense spring flood help to explain the higher concentrations of labile carbon in the northern catchment. Lower lability of DOM as well as higher colour in the southern catchments suggest that wetlands (i.e. peat bogs) may be the dominant source of DOM in these catchments, particularly in periods of low flow. With climate change expected to increase precipitation events and temperatures across the region, the supply and quality of DOM delivered to the Baltic Sea can also be expected to change. Our results indicate that DOM supply to the Baltic Sea from boreal rivers will be more stable throughout the year, and potentially have a lower bioavailability

    The presence and potential impact of psychological safety in the healthcare setting: an evidence synthesis

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    Introduction: Psychological safety is the shared belief that the team is safe for interpersonal risk taking. Its presence improves innovation and error prevention. This evidence synthesis had 3 objectives: explore the current literature regarding psychological safety, identify methods used in its assessment and investigate for evidence of consequences of a psychologically safe environment. Methods: We searched multiple trial registries through December 2018. All studies addressing psychological safety within healthcare workers were included and reviewed for methodological limitations. A thematic analysis approach explored the presence of psychological safety. Content analysis was utilised to evaluate potential consequences. Results: We included 62 papers from 19 countries. The thematic analysis demonstrated high and low levels of psychological safety both at the individual level in study participants and across the studies themselves. There was heterogeneity in responses across all studies, limiting generalisable conclusions about the overall presence of psychological safety. A wide range of methods were used. Twenty-five used qualitative methodology, predominantly semi-structured interviews. Thirty quantitative or mixed method studies used surveys. Ten studies inferred that low psychological safety negatively impacted patient safety. Nine demonstrated a significant relationship between psychological safety and team outcomes. The thematic analysis allowed the development of concepts beyond the content of the original studies. This analytical process provided a wealth of information regarding facilitators and barriers to psychological safety and the development of a model demonstrating the influence of situational context. Discussion: This evidence synthesis highlights that whilst there is a positive and demonstrable presence of psychological safety within healthcare workers worldwide, there is room for improvement. The variability in methods used demonstrates scope to harmonise this. We draw attention to potential consequences of both high and low psychological safety. We provide novel information about the influence of situational context on an individual’s psychological safety and offer more detail about the facilitators and barriers to psychological safety than seen in previous reviews. There is a risk of participation bias - centres involved in safety research may be more aligned to these ideals. The data in this synthesis are useful for institutions looking to improve psychological safety by providing a framework from which modifiable factors can be identified

    Effects of wastewater treatment plant effluent inputs on planktonic metabolic rates and microbial community composition in the Baltic Sea

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    The Baltic Sea is the world's largest area suffering from eutrophication-driven hypoxia. Low oxygen levels are threatening its biodiversity and ecosystem functioning. The main causes for eutrophication-driven hypoxia are high nutrient loadings and global warming. Wastewater treatment plants (WWTP) contribute to eutrophication as they are important sources of nitrogen to coastal areas. Here, we evaluated the effects of wastewater treatment plant effluent inputs on Baltic Sea planktonic communities in four experiments. We tested for effects of effluent inputs on chlorophyll <i>a</i> content, bacterial community composition, and metabolic rates: gross primary production (GPP), net community production (NCP), community respiration (CR) and bacterial production (BP). Nitrogen-rich dissolved organic matter (DOM) inputs from effluents increased bacterial production and decreased primary production and community respiration. Nutrient amendments and seasonally variable environmental conditions lead to lower alpha-diversity and shifts in bacterial community composition (e.g. increased abundance of a few cyanobacterial populations in the summer experiment), concomitant with changes in metabolic rates. An increase in BP and decrease in CR could be caused by high lability of the DOM that can support secondary bacterial production, without an increase in respiration. Increases in bacterial production and simultaneous decreases of primary production lead to more carbon being consumed in the microbial loop, and may shift the ecosystem towards heterotrophy

    A large-scale R-matrix calculation for electron-impact excitation of the Ne2+^{2+} O-like ion

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    The five JΠ\Pi levels within a np2np^2 or np4np^4 ground state complex provide an excellent testing ground for the comparison of theoretical line ratios with astrophysically observed values, in addition to providing valuable electron temperature and density diagnostics. The low temperature nature of the line ratios ensure that the theoretically derived values are sensitive to the underlying atomic structure and electron-impact excitation rates. Previous R-matrix calculations for the Ne2+^{2+} O-like ion exhibit large spurious structure in the cross sections at higher electron energies, which may affect Maxwellian averaged rates even at low temperatures. Furthermore, there is an absence of comprehensive excitation data between the excited states that may provide newer diagnostics to compliment the more established lines discussed in this paper. To resolve these issues, we present both a small scale 56-level Breit-Pauli (BP) calculation and a large-scale 554 levels R-matrix Intermediate Coupling Frame Transformation (ICFT) calculation that extends the scope and validity of earlier JAJOM calculations both in terms of the atomic structure and scattering cross sections. Our results provide a comprehensive electron-impact excitation data set for all transitions to higher nn shells. The fundamental atomic data for this O-like ion is subsequently used within a collisional radiative framework to provide the line ratios across a range of electron temperatures and densities of interest in astrophysical observations.Comment: 17 pages, 8 figure

    K-shell photoionization of ground-state Li-like boron ions [B2+^{2+}]: Experiment and Theory

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    Absolute cross sections for the K-shell photoionization of ground-state Li-like boron [B2+^{2+}(1s2^22s 2^2S)] ions were measured by employing the ion-photon merged-beams technique at the Advanced Light Source synchrotron radiation facility. The energy ranges 197.5--200.5 eV, 201.9--202.1 eV of the [1s(2s\,2p)3^3P]2^2Po{\rm ^o} and [1s(2s\,2p)1^1P] 2^2Po{\rm ^o} resonances, respectively, were investigated using resolving powers of up to 17\,600. The energy range of the experiments was extended to about 238.2 eV yielding energies of the most prominent [1s(2ℓ\ell\,nℓâ€Č\ell^{\prime})]2^2Po^o resonances with an absolute accuracy of the order of 130 ppm. The natural linewidths of the [1s(2s\,2p)3^3P] 2^2Po{\rm ^o} and [1s(2s\,2p)1^1P] 2^2Po{\rm ^o} resonances were measured to be 4.8±0.64.8 \pm 0.6 meV and 29.7±2.529.7 \pm 2.5 meV, respectively, which compare favourably with theoretical results of 4.40 meV and 30.53 meV determined using an intermediate coupling R-matrix method.Comment: 6 figures and 2 table

    State-resolved valence shell photoionization of Be-like ions: experiment and theory

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    High-resolution photoionization experiments were carried out using beams of Be-like C2+^{2+}, N3+^{3+}, and O4+^{4+} ions with roughly equal populations of the 1^1S ground-state and the 3^3Po^o manifold of metastable components. The energy scales of the experiments are calibrated with uncertainties of 1 to 10 meV depending on photon energy. Resolving powers beyond 20,000 were reached allowing for the separation of contributions from the individual metastable 3^3P0o^o_0, 3^3P1o^o_1, and 3^3P2o^o_2 states. The measured data compare favourably with semi-relativistic Breit-Pauli R-matrixComment: 23 figures and 3 table

    Genetic Patterns in Peripheral Marine Populations of the Fusilier Fish Caesio Cuning Within the Kuroshio Current

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    Aim: Mayr’s central‐peripheral population model (CCPM) describes the marked differences between central and peripheral populations in genetic diversity, gene flow, and census size. When isolation leads to genetic divergence, these peripheral populations have high evolutionary value and can influence biogeographic patterns. In tropical marine species with pelagic larvae, powerful western‐boundary currents have great potential to shape the genetic characteristics of peripheral populations at latitudinal extremes. We tested for the genetic patterns expected by the CCPM in peripheral populations that are located within the Kuroshio Current for the Indo‐Pacific reef fish, Caesio cuning. Methods: We used a panel of 2,677 SNPs generated from restriction site‐associated DNA (RAD) sequencing to investigate genetic diversity, relatedness, effective population size, and spatial patterns of population connectivity from central to peripheral populations of C. cuning along the Kuroshio Current. Results: Principal component and cluster analyses indicated a genetically distinct lineage at the periphery of the C. cuning species range and examination of SNPs putatively under divergent selection suggested potential for local adaptation in this region. We found signatures of isolation‐by‐distance and significant genetic differences between nearly all sites. Sites closest to the periphery exhibited increased within‐population relatedness and decreased effective population size. Main Conclusions: Despite the potential for homogenizing gene flow along the Kuroshio Current, peripheral populations in C. cuning conform to the predictions of the CCPM. While oceanography, habitat availability, and dispersal ability are all likely to shape the patterns found in C. cuning across this central‐peripheral junction, the impacts of genetic drift and natural selection in increasing smaller peripheral populations appear to be probable influences on the lineage divergence found in the Ryukyu Islands

    K-shell photoionization of ground-state Li-like carbon ions [C3+^{3+}]: experiment, theory and comparison with time-reversed photorecombination

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    Absolute cross sections for the K-shell photoionization of ground-state Li-like carbon [C3+^{3+}(1s2^22s 2^2S)] ions were measured by employing the ion-photon merged-beams technique at the Advanced Light Source. The energy ranges 299.8--300.15 eV, 303.29--303.58 eV and 335.61--337.57 eV of the [1s(2s2p)3^3P]2^2P, [1s(2s2p)1^1P]2^2P and [(1s2s)3^3S 3p]2^2P resonances, respectively, were investigated using resolving powers of up to 6000. The autoionization linewidth of the [1s(2s2p)1^1P]2^2P resonance was measured to be 27±527 \pm 5 meV and compares favourably with a theoretical result of 26 meV obtained from the intermediate coupling R-Matrix method. The present photoionization cross section results are compared with the outcome from photorecombination measurements by employing the principle of detailed balance.Comment: 3 figures and 2 table
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