Search

Net ecosystem production (NEP) by submerged aquatic vegetation plays a substantial role in capturing atmospheric carbon dioxide into aquatic ecosystems. In lakes and estuaries, the net uptake of carbon dioxide by submerged aquatic vegetation is mediated by stratification of the water column which suppresses the vertical flux of carbon dioxide between the upper and lower layers. The presence of submerged aquatic vegetation can also affect the strength of stratification such that the interactions between vegetation, stratification, and NEP can moderate the carbon dioxide emissions. Since stratification can occur in lakes and estuaries, there is need for a new numerical approach able to consider the effect of submerged aquatic vegetation on stratification, NEP, and carbon dioxide. This study aims to develop a model to investigate how stratification, mediated by vegetation density and flexibility, affects the partial pressure of carbon dioxide (pCO2) and dissolved inorganic carbon (DIC). After initial parameterization of coefficients based on experimental work, horizontal and vertical variations in DIC were successfully modeled by a spatially (horizontally) integrated DIC (SiDIC) model, which was validated with field observations from an estuarine and freshwater lake case study. The SiDIC model was able to reproduce the pCO2 changes between daytime and nighttime throughout the water column. Sensitivity tests showed that the fluctuation of pCO2 was controlled by the suppression of stratification due to the density of submerged aquatic vegetation. The results highlight the importance of resolving vegetation‐induced stratification when modeling the carbon budget within freshwater lakes and coastal environments. Plain Language Summary: The key idea of the present study is that "vegetation‐induced stratification" suppresses vertical mixing in lakes and plays a substantial role in determining how much atmospheric carbon dioxide exchanges with the water. Field observations in Komuke Lagoon and Lake Monger were used to create a representative data set for understanding dissolved inorganic carbon (DIC) metabolism in coastal and freshwater lake ecosystems, respectively. A spatially integrated DIC model was then created to reveal that the fluctuation of partial pressure of carbon dioxide was controlled by the suppression of stratification which is related to the density of submerged aquatic vegetation. The results demonstrate the effect of submerged aquatic vegetation on the vertical mixing of DIC, with implications for our understanding of carbon capture within aquatic ecosystems. Key Points: Submerged vegetation promotes stratification in shallow freshwater and coastal lakes which can impact net CO2 captureModel results demonstrate that vegetation properties mediate the diurnal pCO2 excursion by influencing vertical exchange with the canopyThe results highlight the importance of resolving vegetation‐mediated changes in mixing when estimating carbon uptake by submerged canopies [ABSTRACT FROM AUTHOR]

Aquatic models used for both freshwater and marine systems frequently need to account for submerged aquatic vegetation (SAV) due to its influence on flow and water quality. Despite its importance, parameterizations are generally adopted that simplify feedbacks from SAV, such as canopy properties (e.g., considering the deflected vegetation height) and the bulk friction coefficient. This study reports the development of a fine‐scale non‐hydrostatic model that demonstrates the two‐way effects of SAV motion interaction with the flow. An object‐oriented approach is applied to capture the multiphase phenomena, whereby a leaf‐scale SAV model based on a discrete element method is combined with a flow dynamics model to resolve stresses from currents and waves. The model is verified through application to a laboratory‐scale seagrass bed. A force balance analysis revealed that leaf elasticity and buoyancy are the most significant components influencing the horizontal and vertical momentum equations, respectively. The sensitivity of canopy‐scale bulk friction coefficients to water depth, current speeds, and vegetation density of seagrass was explored. Deeper water was also shown to lead to a smaller decrease in vegetation height. The model approach can contribute to improving assessment of processes influencing water quality, sediment stabilization, carbon sequestration, and SAV restoration, thereby supporting an understanding of how waterways and coasts will respond to changes brought about by development and a changing climate. Plain Language Summary: Aquatic system models that capture aquatic vegetation are increasingly important to help us understand processes controlling carbon budgets (e.g., "blue carbon") and for planning restoration efforts (e.g., Adams et al., 2016, https://doi.org/10.1002/lno.10319). Current models all rely on "static" approaches to account for vegetation via bulk parameterizations, though we know vegetation motion is important (e.g., Abdolahpour et al., 2018, https://doi.org/10.1002/lno.11008). Our study is the first to model the feedback between blade‐scale vegetation motion and hydrodynamics to show it is crucial in shaping bottom mixing processes with implications for carbon and nutrient deposition. Key Points: A model is presented to capture the changing position of Submerged Aquatic Vegetation blades and validated using laboratory experimentsForcing terms that control seagrass movement within a meadow are evaluatedEstimates of deflected vegetation height and bulk meadow friction coefficients demonstrate the importance of simulating SAV motion [ABSTRACT FROM AUTHOR]

In these patients, DOC monotherapy or gemcitabine was the most common treatment approach (two patients), followed by paclitaxel (PTX) monotherapy, PTX/trastuzumab or DOC/trastuzumab. Dear Editor, Metastatic extramammary Paget disease (EMPD) is an intractable condition refractory to conventional treatments; outcomes remain unsatisfactory.1 Establishing an effective regimen with higher response rates and long-term efficacy is needed. Nevertheless, our study revealed that S-1/DOC may be more efficacious than conventional chemotherapy in patients with chemotherapy-naïve metastatic EMPD, with the potential to become a first-line treatment or key regimen in cases of DOC monotherapy failure. [Extracted from the article]

Presents a study which characterized the growth interruption interface in organometallic vapor-phase epitaxial silicon-doped gallium arsenide layers by mobility profiling. Methodology; Results and discussion; Conclusion.

The demand for miniaturized parts and miniaturized semi-finished products is increasing nowadays, because microforming processes can improve production rate and minimize material waste due to less forming passes. However, traditional macro metal forming processes and modelling cannot be simply scaled down to produce miniaturized micro parts. In this study, a 2-Hi micro rolling mill has been successfully built. Experimental and numerical investigations on the micro rolling process for ultra-thin SUS 304 stainless steel strip have been conducted. The experimental results show that the micro rolling deformation of ultra-thin strip is influenced by size effect which results from the specimen size difference and this size effect is embodied in the flow stress and the friction coefficient. Analytical and finite element (FE) models in describing size effect related phenomena, such as flow stress, friction, rolling force and deformation behaviour, are proposed. The material surface constraint and the material deformation mode are critical in determination of material flow stress curve. The analysis of surface roughness evolution with rolling conditions has also been performed. The identified analysis on deformation mechanics provides a basis for further exploration of the material behaviour in plastic deformation of micro scale and the development of micro scale products via micro rolling. [ABSTRACT FROM AUTHOR]

We studied a relation between distal right coronary arterial (dRCA) flow demonstration and perinatal outcome in growth-restricted fetuses (FGR). We investigated fetal biometry, cardiothoracic area ratio (CTAR), amniotic fluid index, Doppler examinations (umbilical artery, middle cerebral artery, aortic isthmus, ductus venosus). OC04.08: Distal right coronary arterial flow demonstration in growth-restricted fetuses: a sign of heart-sparing effect related to adverse perinatal outcome. [Extracted from the article]

An abstract for the article "Prenatal demonstration of distal right coronary artery in normal and growth-restricted fetuses: a plausible sign of heart-sparing effect?" by S. Miyashita and others is presented.

Association of the C825T G-protein β3 subunit (GNB3) gene polymorphism with cardiovascular disease (CVD) incidence was examined in a population-based longitudinal study of the Japanese individuals. The incidence of CVD (stroke and coronary heart disease (CHD)) was assessed in a cohort population (n=1524) consisting of participants of the 2001-2005 Funagata study through March 2008. Cumulative incidences according to genotype were compared with the Kaplan-Meier product-limit method. During the follow-up, 78 subjects experienced a CVD event (stroke: n=54; CHD: n=30; both consecutively: n=6). At the end of the follow-up (longest and median follow-up periods: 81 and 68 months, respectively), the cumulative incidence of CVD for the TT genotype was significantly higher than that of the C-carriers (0.077 vs 0.042, P=0.004). Blood pressures and the prevalence of hypertension were not different between the genotypes. Cox's proportional hazard analysis showed that the TT genotype is a significant risk factor for CVD (hazard ratio (HR)=1.82 (95% confidence interval (CI) 1.14-2.89); P=0.012) and stroke (HR=1.76 (95% CI: 1.01-3.07); P=0.048) incidences after adjustment for age, sex, hypertension, hyperlipidemia, diabetes, alcohol drinking and smoking at baseline. The TT genotype of the C825T GNB3 gene polymorphism was found to be a significant risk factor for the incidence of CVD and stroke independent of hypertension and other established CVD risk factors in a Japanese population. [ABSTRACT FROM AUTHOR]

Unique atomic structures at the edges of graphenes yield a variety of interesting phenomena. In spite of carbon-based material with only sp bonds, the zigzag-type atomic structure of graphene edges theoretically produces spontaneous spin polarization of electrons due to mutual Coulomb interaction of extremely high electron density of states localizing at the flat energy band. However, spin-based phenomena have been experimentally observed only in defect-related carbon systems. Here, we fabricate honeycomb-like arrays of low-defect hexagonal nanopores (graphene nanomeshes; GNMs) on graphenes, which produce a large amount of pore edges, by using a nonlithographic method (nanoporous alumina templates). We find large-magnitude ferromagnetism arising from polarized electron spins localizing at the zigzag-nanopore edges of monolayer GNMs. Moreover, spin pumping effect depending on GNM structures is found for magnetic fields applied in parallel with the few-layer GNM planes. These promise to be a realization of rare-element free magnets and also novel all-carbon spintronic devices. [ABSTRACT FROM AUTHOR]

To clarify the clinical features and outcome of Stenotrophomonas maltophilia infection among hematopoietic SCT (HCT) recipients, we retrospectively reviewed the records of 1085 consecutive HCT recipients and identified 42 episodes in 31 HCT recipients with S. maltophilia infection. We compared these recipients with 30 non-HCT patients with S. maltophilia infection. The mortality rate in HCT recipients was significantly higher than that in non-HCT patients (relative risk 5.7, P=0.04), and we identified seven patients with pulmonary hemorrhage due to S. maltophilia, exclusively in the HCT cohort. Six of these latter seven patients died within 1 day from the onset of hemorrhage and the isolate was identified after death in most cases; one patient, who received empiric therapy for S. maltophilia and granulocyte transfusion, survived for more than 2 weeks. The patients with pulmonary hemorrhage had a more severe and longer duration of neutropenia, persistent fever despite of the use of broad-spectrum antibiotics, complication by pneumonia and higher C-reactive protein levels than those without pulmonary hemorrhage. In conclusion, S. maltophilia was associated with fulminant and fatal pulmonary hemorrhage in HCT recipients. Empiric therapy with antibiotics before the onset of pulmonary hemorrhage may be effective in HCT recipients who carry the conditions identified. [ABSTRACT FROM AUTHOR]

The zigzag-type atomic structure at edges of graphenes theoretically produces flat energy band. Because electrons have infinite effective mass at the flat band, they localize at zigzag edges with high densities. The localized electron spins are spontaneously polarized due to mutual Coulomb interaction in spite of a material consisting of only carbon atom with sp2 bonds. However, in most experimental studies, spin polarization (such as ferromagnetism) has been observed in defect-related carbon systems. Here, we fabricate honeycomb-like arrays of low-defect hexagonal antidots (nanopores) terminated by hydrogen atoms on graphenes. They are prepared by a non-lithographic method using nanoporous alumina templates. We find large-magnitude ferromagnetism arising from polarized electron spins localizing at the zigzag antidot edges. Moreover, weak hysteresis loop in magnetoresistance and also spin pumping effect are found for perpendicular and parallel magnetic fields applied to the few-layer antidot lattices with larger inter-antidot space. These promise to be a realization of rare-element free magnets and also novel spintronic devices such as all-carbon spin transistors. [ABSTRACT FROM AUTHOR]

The so-called zigzag edge of graphenes has localized and strongly spin-polarized electrons. However, magnetoresistance (MR) behavior associated with the edge electrons has not been reported in graphenes. Here, we measure MR of graphene antidot-lattices, honeycomb-like arrays of hexagonal antidots with a large ensemble of hydrogen-terminated and low-defect antidot edges, prepared by a nonlithographic method using nanoporous alumina templates. We find anomalous MR oscillations arising from localized electron spins existing at the antidot edges. These are promising for realization of spintronic devices. [ABSTRACT FROM AUTHOR]